use buffer_string_set_length() to truncate strings

[lighttpd.git] / src / mod_scgi.c

#include "first.h"

#include "buffer.h"
#include "server.h"
#include "keyvalue.h"
#include "log.h"

#include "http_chunk.h"
#include "fdevent.h"
#include "connections.h"
#include "response.h"
#include "joblist.h"

#include "plugin.h"

#include "inet_ntop_cache.h"

#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <assert.h>
#include <signal.h>

#include <stdio.h>

#include "sys-socket.h"

#ifdef HAVE_SYS_UIO_H
# include <sys/uio.h>
#endif

#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif

#include "version.h"

enum {EOL_UNSET, EOL_N, EOL_RN};

/*
 *
 * TODO:
 *
 * - add timeout for a connect to a non-scgi process
 *   (use state_timestamp + state)
 *
 */

typedef struct scgi_proc {
        size_t id; /* id will be between 1 and max_procs */
        buffer *socket; /* config.socket + "-" + id */
        unsigned port;  /* config.port + pno */

        pid_t pid;   /* PID of the spawned process (0 if not spawned locally) */


        size_t load; /* number of requests waiting on this process */

        time_t last_used; /* see idle_timeout */
        size_t requests;  /* see max_requests */
        struct scgi_proc *prev, *next; /* see first */

        time_t disable_ts; /* replace by host->something */

        int is_local;

        enum { PROC_STATE_UNSET,            /* init-phase */
                        PROC_STATE_RUNNING, /* alive */
                        PROC_STATE_DIED_WAIT_FOR_PID,
                        PROC_STATE_KILLED,  /* was killed as we don't have the load anymore */
                        PROC_STATE_DIED,    /* marked as dead, should be restarted */
                        PROC_STATE_DISABLED /* proc disabled as it resulted in an error */
        } state;
} scgi_proc;

typedef struct {
        /* list of processes handling this extension
         * sorted by lowest load
         *
         * whenever a job is done move it up in the list
         * until it is sorted, move it down as soon as the
         * job is started
         */
        scgi_proc *first;
        scgi_proc *unused_procs;

        /*
         * spawn at least min_procs, at max_procs.
         *
         * as soon as the load of the first entry
         * is max_load_per_proc we spawn a new one
         * and add it to the first entry and give it
         * the load
         *
         */

        unsigned short min_procs;
        unsigned short max_procs;
        size_t num_procs;    /* how many procs are started */
        size_t active_procs; /* how many of them are really running */

        unsigned short max_load_per_proc;

        /*
         * kick the process from the list if it was not
         * used for idle_timeout until min_procs is
         * reached. this helps to get the processlist
         * small again we had a small peak load.
         *
         */

        unsigned short idle_timeout;

        /*
         * time after a disabled remote connection is tried to be re-enabled
         *
         *
         */

        unsigned short disable_time;

        /*
         * same scgi processes get a little bit larger
         * than wanted. max_requests_per_proc kills a
         * process after a number of handled requests.
         *
         */
        size_t max_requests_per_proc;


        /* config */

        /*
         * host:port
         *
         * if host is one of the local IP adresses the
         * whole connection is local
         *
         * if tcp/ip should be used host AND port have
         * to be specified
         *
         */
        buffer *host;
        unsigned short port;
        sa_family_t family;

        /*
         * Unix Domain Socket
         *
         * instead of TCP/IP we can use Unix Domain Sockets
         * - more secure (you have fileperms to play with)
         * - more control (on locally)
         * - more speed (no extra overhead)
         */
        buffer *unixsocket;

        /* if socket is local we can start the scgi
         * process ourself
         *
         * bin-path is the path to the binary
         *
         * check min_procs and max_procs for the number
         * of process to start-up
         */
        buffer *bin_path;

        /* bin-path is set bin-environment is taken to
         * create the environement before starting the
         * FastCGI process
         *
         */
        array *bin_env;

        array *bin_env_copy;

        /*
         * docroot-translation between URL->phys and the
         * remote host
         *
         * reasons:
         * - different dir-layout if remote
         * - chroot if local
         *
         */
        buffer *docroot;

        /*
         * check_local tell you if the phys file is stat()ed
         * or not. FastCGI doesn't care if the service is
         * remote. If the web-server side doesn't contain
         * the scgi-files we should not stat() for them
         * and say '404 not found'.
         */
        unsigned short check_local;

        /*
         * append PATH_INFO to SCRIPT_FILENAME
         *
         * php needs this if cgi.fix_pathinfo is provied
         *
         */

        /*
         * workaround for program when prefix="/"
         *
         * rule to build PATH_INFO is hardcoded for when check_local is disabled
         * enable this option to use the workaround
         *
         */

        unsigned short fix_root_path_name;

        /*
         * If the backend includes X-Sendfile in the response
         * we use the value as filename and ignore the content.
         *
         */
        unsigned short xsendfile_allow;
        array *xsendfile_docroot;

        ssize_t load; /* replace by host->load */

        size_t max_id; /* corresponds most of the time to
        num_procs.

        only if a process is killed max_id waits for the process itself
        to die and decrements its afterwards */

        int listen_backlog;
} scgi_extension_host;

/*
 * one extension can have multiple hosts assigned
 * one host can spawn additional processes on the same
 *   socket (if we control it)
 *
 * ext -> host -> procs
 *    1:n     1:n
 *
 * if the scgi process is remote that whole goes down
 * to
 *
 * ext -> host -> procs
 *    1:n     1:1
 *
 * in case of PHP and FCGI_CHILDREN we have again a procs
 * but we don't control it directly.
 *
 */

typedef struct {
        buffer *key; /* like .php */

        int note_is_sent;
        scgi_extension_host **hosts;

        size_t used;
        size_t size;
} scgi_extension;

typedef struct {
        scgi_extension **exts;

        size_t used;
        size_t size;
} scgi_exts;


typedef struct {
        scgi_exts *exts;

        int debug;
} plugin_config;

typedef struct {
        char **ptr;

        size_t size;
        size_t used;
} char_array;

/* generic plugin data, shared between all connections */
typedef struct {
        PLUGIN_DATA;

        buffer *scgi_env;

        buffer *path;
        buffer *parse_response;

        plugin_config **config_storage;

        plugin_config conf; /* this is only used as long as no handler_ctx is setup */
} plugin_data;

/* connection specific data */
typedef enum { FCGI_STATE_INIT, FCGI_STATE_CONNECT, FCGI_STATE_PREPARE_WRITE,
                FCGI_STATE_WRITE, FCGI_STATE_READ
} scgi_connection_state_t;

typedef struct {
        buffer  *response;
        size_t   response_len;
        int      response_type;
        int      response_padding;

        scgi_proc *proc;
        scgi_extension_host *host;

        scgi_connection_state_t state;
        time_t   state_timestamp;

        int      reconnects; /* number of reconnect attempts */

        chunkqueue *wb;

        buffer   *response_header;

        int       delayed;   /* flag to mark that the connect() is delayed */

        size_t    request_id;
        int       fd;        /* fd to the scgi process */
        int       fde_ndx;   /* index into the fd-event buffer */

        pid_t     pid;
        int       got_proc;

        plugin_config conf;

        connection *remote_conn;  /* dumb pointer */
        plugin_data *plugin_data; /* dumb pointer */
} handler_ctx;


/* ok, we need a prototype */
static handler_t scgi_handle_fdevent(server *srv, void *ctx, int revents);

int scgi_proclist_sort_down(server *srv, scgi_extension_host *host, scgi_proc *proc);

static void reset_signals(void) {
#ifdef SIGTTOU
        signal(SIGTTOU, SIG_DFL);
#endif
#ifdef SIGTTIN
        signal(SIGTTIN, SIG_DFL);
#endif
#ifdef SIGTSTP
        signal(SIGTSTP, SIG_DFL);
#endif
        signal(SIGHUP, SIG_DFL);
        signal(SIGPIPE, SIG_DFL);
        signal(SIGUSR1, SIG_DFL);
}

static handler_ctx * handler_ctx_init(void) {
        handler_ctx * hctx;

        hctx = calloc(1, sizeof(*hctx));
        force_assert(hctx);

        hctx->fde_ndx = -1;

        hctx->response = buffer_init();
        hctx->response_header = buffer_init();

        hctx->request_id = 0;
        hctx->state = FCGI_STATE_INIT;
        hctx->proc = NULL;

        hctx->response_len = 0;
        hctx->response_type = 0;
        hctx->response_padding = 0;
        hctx->fd = -1;

        hctx->reconnects = 0;

        hctx->wb = chunkqueue_init();

        return hctx;
}

static void handler_ctx_free(handler_ctx *hctx) {
        buffer_free(hctx->response);
        buffer_free(hctx->response_header);

        chunkqueue_free(hctx->wb);

        free(hctx);
}

static scgi_proc *scgi_process_init(void) {
        scgi_proc *f;

        f = calloc(1, sizeof(*f));
        force_assert(f);
        f->socket = buffer_init();

        f->prev = NULL;
        f->next = NULL;

        return f;
}

static void scgi_process_free(scgi_proc *f) {
        if (!f) return;

        scgi_process_free(f->next);

        buffer_free(f->socket);

        free(f);
}

static scgi_extension_host *scgi_host_init(void) {
        scgi_extension_host *f;

        f = calloc(1, sizeof(*f));

        f->host = buffer_init();
        f->unixsocket = buffer_init();
        f->docroot = buffer_init();
        f->bin_path = buffer_init();
        f->bin_env = array_init();
        f->bin_env_copy = array_init();
        f->xsendfile_docroot = array_init();

        return f;
}

static void scgi_host_free(scgi_extension_host *h) {
        if (!h) return;

        buffer_free(h->host);
        buffer_free(h->unixsocket);
        buffer_free(h->docroot);
        buffer_free(h->bin_path);
        array_free(h->bin_env);
        array_free(h->bin_env_copy);
        array_free(h->xsendfile_docroot);

        scgi_process_free(h->first);
        scgi_process_free(h->unused_procs);

        free(h);

}

static scgi_exts *scgi_extensions_init(void) {
        scgi_exts *f;

        f = calloc(1, sizeof(*f));
        force_assert(f);

        return f;
}

static void scgi_extensions_free(scgi_exts *f) {
        size_t i;

        if (!f) return;

        for (i = 0; i < f->used; i++) {
                scgi_extension *fe;
                size_t j;

                fe = f->exts[i];

                for (j = 0; j < fe->used; j++) {
                        scgi_extension_host *h;

                        h = fe->hosts[j];

                        scgi_host_free(h);
                }

                buffer_free(fe->key);
                free(fe->hosts);

                free(fe);
        }

        free(f->exts);

        free(f);
}

static int scgi_extension_insert(scgi_exts *ext, buffer *key, scgi_extension_host *fh) {
        scgi_extension *fe;
        size_t i;

        /* there is something */

        for (i = 0; i < ext->used; i++) {
                if (buffer_is_equal(key, ext->exts[i]->key)) {
                        break;
                }
        }

        if (i == ext->used) {
                /* filextension is new */
                fe = calloc(1, sizeof(*fe));
                force_assert(fe);
                fe->key = buffer_init();
                buffer_copy_buffer(fe->key, key);

                /* */

                if (ext->size == 0) {
                        ext->size = 8;
                        ext->exts = malloc(ext->size * sizeof(*(ext->exts)));
                        force_assert(ext->exts);
                } else if (ext->used == ext->size) {
                        ext->size += 8;
                        ext->exts = realloc(ext->exts, ext->size * sizeof(*(ext->exts)));
                        force_assert(ext->exts);
                }
                ext->exts[ext->used++] = fe;
        } else {
                fe = ext->exts[i];
        }

        if (fe->size == 0) {
                fe->size = 4;
                fe->hosts = malloc(fe->size * sizeof(*(fe->hosts)));
                force_assert(fe->hosts);
        } else if (fe->size == fe->used) {
                fe->size += 4;
                fe->hosts = realloc(fe->hosts, fe->size * sizeof(*(fe->hosts)));
                force_assert(fe->hosts);
        }

        fe->hosts[fe->used++] = fh;

        return 0;

}

INIT_FUNC(mod_scgi_init) {
        plugin_data *p;

        p = calloc(1, sizeof(*p));
        force_assert(p);

        p->scgi_env = buffer_init();

        p->path = buffer_init();
        p->parse_response = buffer_init();

        return p;
}


FREE_FUNC(mod_scgi_free) {
        plugin_data *p = p_d;

        UNUSED(srv);

        buffer_free(p->scgi_env);
        buffer_free(p->path);
        buffer_free(p->parse_response);

        if (p->config_storage) {
                size_t i, j, n;
                for (i = 0; i < srv->config_context->used; i++) {
                        plugin_config *s = p->config_storage[i];
                        scgi_exts *exts;

                        if (NULL == s) continue;

                        exts = s->exts;

                        for (j = 0; j < exts->used; j++) {
                                scgi_extension *ex;

                                ex = exts->exts[j];

                                for (n = 0; n < ex->used; n++) {
                                        scgi_proc *proc;
                                        scgi_extension_host *host;

                                        host = ex->hosts[n];

                                        for (proc = host->first; proc; proc = proc->next) {
                                                if (proc->pid != 0) kill(proc->pid, SIGTERM);

                                                if (proc->is_local &&
                                                    !buffer_string_is_empty(proc->socket)) {
                                                        unlink(proc->socket->ptr);
                                                }
                                        }

                                        for (proc = host->unused_procs; proc; proc = proc->next) {
                                                if (proc->pid != 0) kill(proc->pid, SIGTERM);

                                                if (proc->is_local &&
                                                    !buffer_string_is_empty(proc->socket)) {
                                                        unlink(proc->socket->ptr);
                                                }
                                        }
                                }
                        }

                        scgi_extensions_free(s->exts);

                        free(s);
                }
                free(p->config_storage);
        }

        free(p);

        return HANDLER_GO_ON;
}

static int env_add(char_array *env, const char *key, size_t key_len, const char *val, size_t val_len) {
        char *dst;
        size_t i;

        if (!key || !val) return -1;

        dst = malloc(key_len + val_len + 3);
        force_assert(dst);
        memcpy(dst, key, key_len);
        dst[key_len] = '=';
        /* add the \0 from the value */
        memcpy(dst + key_len + 1, val, val_len + 1);

        for (i = 0; i < env->used; i++) {
                if (0 == strncmp(dst, env->ptr[i], key_len + 1)) {
                        /* don't care about free as we are in a forked child which is going to exec(...) */
                        /* free(env->ptr[i]); */
                        env->ptr[i] = dst;
                        return 0;
                }
        }

        if (env->size == 0) {
                env->size = 16;
                env->ptr = malloc(env->size * sizeof(*env->ptr));
                force_assert(env->ptr);
        } else if (env->size == env->used) {
                env->size += 16;
                env->ptr = realloc(env->ptr, env->size * sizeof(*env->ptr));
                force_assert(env->ptr);
        }

        env->ptr[env->used++] = dst;

        return 0;
}

#if !defined(HAVE_FORK)
static int scgi_spawn_connection(server *srv,
                                 plugin_data *p,
                                 scgi_extension_host *host,
                                 scgi_proc *proc) {
        UNUSED(srv);
        UNUSED(p);
        UNUSED(host);
        UNUSED(proc);
        return -1;
}

#else /* -> defined(HAVE_FORK) */

static int scgi_spawn_connection(server *srv,
                                 plugin_data *p,
                                 scgi_extension_host *host,
                                 scgi_proc *proc) {
        int scgi_fd;
        int status;
        struct timeval tv = { 0, 100 * 1000 };
#ifdef HAVE_SYS_UN_H
        struct sockaddr_un scgi_addr_un;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
        struct sockaddr_in6 scgi_addr_in6;
#endif
        struct sockaddr_in scgi_addr_in;
        struct sockaddr *scgi_addr;

        socklen_t servlen;

        if (p->conf.debug) {
                log_error_write(srv, __FILE__, __LINE__, "sdb",
                                "new proc, socket:", proc->port, proc->socket);
        }


        if (!buffer_string_is_empty(proc->socket)) {
#ifdef HAVE_SYS_UN_H
                memset(&scgi_addr_un, 0, sizeof(scgi_addr_un));
                scgi_addr_un.sun_family = AF_UNIX;
                if (buffer_string_length(proc->socket) + 1 > sizeof(scgi_addr_un.sun_path)) {
                        log_error_write(srv, __FILE__, __LINE__, "sB",
                                        "ERROR: Unix Domain socket filename too long:",
                                        proc->socket);
                        return -1;
                }
                memcpy(scgi_addr_un.sun_path, proc->socket->ptr, buffer_string_length(proc->socket) + 1);

#ifdef SUN_LEN
                servlen = SUN_LEN(&scgi_addr_un);
#else
                /* stevens says: */
                servlen = buffer_string_length(proc->socket) + 1 + sizeof(scgi_addr_un.sun_family);
#endif
                scgi_addr = (struct sockaddr *) &scgi_addr_un;
#else
                log_error_write(srv, __FILE__, __LINE__, "s",
                                "ERROR: Unix Domain sockets are not supported.");
                return -1;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
        } else if (host->family == AF_INET6 && !buffer_string_is_empty(host->host)) {
                memset(&scgi_addr_in6, 0, sizeof(scgi_addr_in6));
                scgi_addr_in6.sin6_family = AF_INET6;
                inet_pton(AF_INET6, host->host->ptr, (char *) &scgi_addr_in6.sin6_addr);
                scgi_addr_in6.sin6_port = htons(proc->port);
                servlen = sizeof(scgi_addr_in6);
                scgi_addr = (struct sockaddr *) &scgi_addr_in6;
#endif
        } else {
                memset(&scgi_addr_in, 0, sizeof(scgi_addr_in));
                scgi_addr_in.sin_family = AF_INET;

                if (buffer_string_is_empty(host->host)) {
                        scgi_addr_in.sin_addr.s_addr = htonl(INADDR_ANY);
                } else {
                        struct hostent *he;

                        /* set a usefull default */
                        scgi_addr_in.sin_addr.s_addr = htonl(INADDR_ANY);


                        if (NULL == (he = gethostbyname(host->host->ptr))) {
                                log_error_write(srv, __FILE__, __LINE__,
                                                "sdb", "gethostbyname failed: ",
                                                h_errno, host->host);
                                return -1;
                        }

                        if (he->h_addrtype != AF_INET) {
                                log_error_write(srv, __FILE__, __LINE__, "sd", "addr-type != AF_INET: ", he->h_addrtype);
                                return -1;
                        }

                        if (he->h_length != sizeof(struct in_addr)) {
                                log_error_write(srv, __FILE__, __LINE__, "sd", "addr-length != sizeof(in_addr): ", he->h_length);
                                return -1;
                        }

                        memcpy(&(scgi_addr_in.sin_addr.s_addr), he->h_addr_list[0], he->h_length);

                }
                scgi_addr_in.sin_port = htons(proc->port);
                servlen = sizeof(scgi_addr_in);

                scgi_addr = (struct sockaddr *) &scgi_addr_in;
        }

        if (-1 == (scgi_fd = socket(scgi_addr->sa_family, SOCK_STREAM, 0))) {
                log_error_write(srv, __FILE__, __LINE__, "ss",
                                "failed:", strerror(errno));
                return -1;
        }

        if (-1 == connect(scgi_fd, scgi_addr, servlen)) {
                /* server is not up, spawn in  */
                pid_t child;
                int val;

                if (!buffer_string_is_empty(proc->socket)) {
                        unlink(proc->socket->ptr);
                }

                close(scgi_fd);

                /* reopen socket */
                if (-1 == (scgi_fd = socket(scgi_addr->sa_family, SOCK_STREAM, 0))) {
                        log_error_write(srv, __FILE__, __LINE__, "ss",
                                "socket failed:", strerror(errno));
                        return -1;
                }

                val = 1;
                if (setsockopt(scgi_fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0) {
                        log_error_write(srv, __FILE__, __LINE__, "ss",
                                        "socketsockopt failed:", strerror(errno));
                        close(scgi_fd);
                        return -1;
                }

                /* create socket */
                if (-1 == bind(scgi_fd, scgi_addr, servlen)) {
                        log_error_write(srv, __FILE__, __LINE__, "sbds",
                                "bind failed for:",
                                proc->socket,
                                proc->port,
                                strerror(errno));
                        close(scgi_fd);
                        return -1;
                }

                if (-1 == listen(scgi_fd, host->listen_backlog)) {
                        log_error_write(srv, __FILE__, __LINE__, "ss",
                                "listen failed:", strerror(errno));
                        close(scgi_fd);
                        return -1;
                }

                switch ((child = fork())) {
                case 0: {
                        buffer *b;
                        size_t i = 0;
                        int fd = 0;
                        char_array env;


                        /* create environment */
                        env.ptr = NULL;
                        env.size = 0;
                        env.used = 0;

                        if (scgi_fd != 0) {
                                dup2(scgi_fd, 0);
                                close(scgi_fd);
                        }

                        /* we don't need the client socket */
                        for (fd = 3; fd < 256; fd++) {
                                close(fd);
                        }

                        /* build clean environment */
                        if (host->bin_env_copy->used) {
                                for (i = 0; i < host->bin_env_copy->used; i++) {
                                        data_string *ds = (data_string *)host->bin_env_copy->data[i];
                                        char *ge;

                                        if (NULL != (ge = getenv(ds->value->ptr))) {
                                                env_add(&env, CONST_BUF_LEN(ds->value), ge, strlen(ge));
                                        }
                                }
                        } else {
                                char ** const e = environ;
                                for (i = 0; e[i]; ++i) {
                                        char *eq;

                                        if (NULL != (eq = strchr(e[i], '='))) {
                                                env_add(&env, e[i], eq - e[i], eq+1, strlen(eq+1));
                                        }
                                }
                        }

                        /* create environment */
                        for (i = 0; i < host->bin_env->used; i++) {
                                data_string *ds = (data_string *)host->bin_env->data[i];

                                env_add(&env, CONST_BUF_LEN(ds->key), CONST_BUF_LEN(ds->value));
                        }

                        for (i = 0; i < env.used; i++) {
                                /* search for PHP_FCGI_CHILDREN */
                                if (0 == strncmp(env.ptr[i], "PHP_FCGI_CHILDREN=", sizeof("PHP_FCGI_CHILDREN=") - 1)) break;
                        }

                        /* not found, add a default */
                        if (i == env.used) {
                                env_add(&env, CONST_STR_LEN("PHP_FCGI_CHILDREN"), CONST_STR_LEN("1"));
                        }

                        env.ptr[env.used] = NULL;

                        b = buffer_init();
                        buffer_copy_string_len(b, CONST_STR_LEN("exec "));
                        buffer_append_string_buffer(b, host->bin_path);

                        reset_signals();

                        /* exec the cgi */
                        execle("/bin/sh", "sh", "-c", b->ptr, (char *)NULL, env.ptr);

                        log_error_write(srv, __FILE__, __LINE__, "sbs",
                                        "execl failed for:", host->bin_path, strerror(errno));

                        _exit(errno);

                        break;
                }
                case -1:
                        /* error */
                        close(scgi_fd);
                        break;
                default:
                        /* father */
                        close(scgi_fd);

                        /* wait */
                        select(0, NULL, NULL, NULL, &tv);

                        switch (waitpid(child, &status, WNOHANG)) {
                        case 0:
                                /* child still running after timeout, good */
                                break;
                        case -1:
                                /* no PID found ? should never happen */
                                log_error_write(srv, __FILE__, __LINE__, "ss",
                                                "pid not found:", strerror(errno));
                                return -1;
                        default:
                                /* the child should not terminate at all */
                                if (WIFEXITED(status)) {
                                        log_error_write(srv, __FILE__, __LINE__, "sd",
                                                        "child exited (is this a SCGI binary ?):",
                                                        WEXITSTATUS(status));
                                } else if (WIFSIGNALED(status)) {
                                        log_error_write(srv, __FILE__, __LINE__, "sd",
                                                        "child signaled:",
                                                        WTERMSIG(status));
                                } else {
                                        log_error_write(srv, __FILE__, __LINE__, "sd",
                                                        "child died somehow:",
                                                        status);
                                }
                                return -1;
                        }

                        /* register process */
                        proc->pid = child;
                        proc->last_used = srv->cur_ts;
                        proc->is_local = 1;

                        break;
                }
        } else {
                close(scgi_fd);

                proc->is_local = 0;
                proc->pid = 0;

                if (p->conf.debug) {
                        log_error_write(srv, __FILE__, __LINE__, "sb",
                                        "(debug) socket is already used, won't spawn:",
                                        proc->socket);
                }
        }

        proc->state = PROC_STATE_RUNNING;
        host->active_procs++;

        return 0;
}

#endif /* HAVE_FORK */

static int unixsocket_is_dup(plugin_data *p, size_t used, buffer *unixsocket) {
        size_t i, j, n;
        for (i = 0; i < used; ++i) {
                scgi_exts *exts = p->config_storage[i]->exts;
                for (j = 0; j < exts->used; ++j) {
                        scgi_extension *ex = exts->exts[j];
                        for (n = 0; n < ex->used; ++n) {
                                scgi_extension_host *host = ex->hosts[n];
                                if (!buffer_string_is_empty(host->unixsocket)
                                    && buffer_is_equal(host->unixsocket, unixsocket))
                                        return 1;
                        }
                }
        }

        return 0;
}

SETDEFAULTS_FUNC(mod_scgi_set_defaults) {
        plugin_data *p = p_d;
        data_unset *du;
        size_t i = 0;
        scgi_extension_host *df = NULL;

        config_values_t cv[] = {
                { "scgi.server",              NULL, T_CONFIG_LOCAL, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
                { "scgi.debug",               NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
                { NULL,                          NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
        };

        p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));
        force_assert(p->config_storage);

        for (i = 0; i < srv->config_context->used; i++) {
                data_config const* config = (data_config const*)srv->config_context->data[i];
                plugin_config *s;

                s = malloc(sizeof(plugin_config));
                force_assert(s);
                s->exts          = scgi_extensions_init();
                s->debug         = 0;

                cv[0].destination = s->exts;
                cv[1].destination = &(s->debug);

                p->config_storage[i] = s;

                if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
                        goto error;
                }

                /*
                 * <key> = ( ... )
                 */

                if (NULL != (du = array_get_element(config->value, "scgi.server"))) {
                        size_t j;
                        data_array *da = (data_array *)du;

                        if (du->type != TYPE_ARRAY) {
                                log_error_write(srv, __FILE__, __LINE__, "sss",
                                                "unexpected type for key: ", "scgi.server", "expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

                                goto error;
                        }


                        /*
                         * scgi.server = ( "<ext>" => ( ... ),
                         *                    "<ext>" => ( ... ) )
                         */

                        for (j = 0; j < da->value->used; j++) {
                                size_t n;
                                data_array *da_ext = (data_array *)da->value->data[j];

                                if (da->value->data[j]->type != TYPE_ARRAY) {
                                        log_error_write(srv, __FILE__, __LINE__, "sssbs",
                                                        "unexpected type for key: ", "scgi.server",
                                                        "[", da->value->data[j]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

                                        goto error;
                                }

                                /*
                                 * da_ext->key == name of the extension
                                 */

                                /*
                                 * scgi.server = ( "<ext>" =>
                                 *                     ( "<host>" => ( ... ),
                                 *                       "<host>" => ( ... )
                                 *                     ),
                                 *                    "<ext>" => ... )
                                 */

                                for (n = 0; n < da_ext->value->used; n++) {
                                        data_array *da_host = (data_array *)da_ext->value->data[n];

                                        config_values_t fcv[] = {
                                                { "host",              NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
                                                { "docroot",           NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
                                                { "socket",            NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 2 */
                                                { "bin-path",          NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 3 */

                                                { "check-local",       NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },      /* 4 */
                                                { "port",              NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 5 */
                                                { "min-procs-not-working",         NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 7 this is broken for now */
                                                { "max-procs",         NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 7 */
                                                { "max-load-per-proc", NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 8 */
                                                { "idle-timeout",      NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 9 */
                                                { "disable-time",      NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },        /* 10 */

                                                { "bin-environment",   NULL, T_CONFIG_ARRAY, T_CONFIG_SCOPE_CONNECTION },        /* 11 */
                                                { "bin-copy-environment", NULL, T_CONFIG_ARRAY, T_CONFIG_SCOPE_CONNECTION },     /* 12 */
                                                { "fix-root-scriptname",  NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },   /* 13 */
                                                { "listen-backlog",    NULL, T_CONFIG_INT,   T_CONFIG_SCOPE_CONNECTION },        /* 14 */
                                                { "x-sendfile",        NULL, T_CONFIG_BOOLEAN, T_CONFIG_SCOPE_CONNECTION },      /* 15 */
                                                { "x-sendfile-docroot",NULL, T_CONFIG_ARRAY,   T_CONFIG_SCOPE_CONNECTION },      /* 16 */


                                                { NULL,                NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
                                        };

                                        if (da_host->type != TYPE_ARRAY) {
                                                log_error_write(srv, __FILE__, __LINE__, "ssSBS",
                                                                "unexpected type for key:",
                                                                "scgi.server",
                                                                "[", da_host->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");

                                                goto error;
                                        }

                                        df = scgi_host_init();

                                        df->check_local  = 1;
                                        df->min_procs    = 4;
                                        df->max_procs    = 4;
                                        df->max_load_per_proc = 1;
                                        df->idle_timeout = 60;
                                        df->disable_time = 60;
                                        df->fix_root_path_name = 0;
                                        df->listen_backlog = 1024;
                                        df->xsendfile_allow = 0;

                                        fcv[0].destination = df->host;
                                        fcv[1].destination = df->docroot;
                                        fcv[2].destination = df->unixsocket;
                                        fcv[3].destination = df->bin_path;

                                        fcv[4].destination = &(df->check_local);
                                        fcv[5].destination = &(df->port);
                                        fcv[6].destination = &(df->min_procs);
                                        fcv[7].destination = &(df->max_procs);
                                        fcv[8].destination = &(df->max_load_per_proc);
                                        fcv[9].destination = &(df->idle_timeout);
                                        fcv[10].destination = &(df->disable_time);

                                        fcv[11].destination = df->bin_env;
                                        fcv[12].destination = df->bin_env_copy;
                                        fcv[13].destination = &(df->fix_root_path_name);
                                        fcv[14].destination = &(df->listen_backlog);
                                        fcv[15].destination = &(df->xsendfile_allow);
                                        fcv[16].destination = df->xsendfile_docroot;


                                        if (0 != config_insert_values_internal(srv, da_host->value, fcv, T_CONFIG_SCOPE_CONNECTION)) {
                                                goto error;
                                        }

                                        if ((!buffer_string_is_empty(df->host) || df->port) &&
                                            !buffer_string_is_empty(df->unixsocket)) {
                                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                                "either host+port or socket");

                                                goto error;
                                        }

                                        if (!buffer_string_is_empty(df->unixsocket)) {
                                                /* unix domain socket */
                                                struct sockaddr_un un;

                                                if (buffer_string_length(df->unixsocket) + 1 > sizeof(un.sun_path) - 2) {
                                                        log_error_write(srv, __FILE__, __LINE__, "s",
                                                                        "path of the unixdomain socket is too large");
                                                        goto error;
                                                }

                                                if (!buffer_string_is_empty(df->bin_path)
                                                    && unixsocket_is_dup(p, i+1, df->unixsocket)) {
                                                        log_error_write(srv, __FILE__, __LINE__, "sb",
                                                                        "duplicate unixsocket path:",
                                                                        df->unixsocket);
                                                        goto error;
                                                }

                                                df->family = AF_UNIX;
                                        } else {
                                                /* tcp/ip */

                                                if (buffer_string_is_empty(df->host) &&
                                                    buffer_string_is_empty(df->bin_path)) {
                                                        log_error_write(srv, __FILE__, __LINE__, "sbbbs",
                                                                        "missing key (string):",
                                                                        da->key,
                                                                        da_ext->key,
                                                                        da_host->key,
                                                                        "host");

                                                        goto error;
                                                } else if (df->port == 0) {
                                                        log_error_write(srv, __FILE__, __LINE__, "sbbbs",
                                                                        "missing key (short):",
                                                                        da->key,
                                                                        da_ext->key,
                                                                        da_host->key,
                                                                        "port");
                                                        goto error;
                                                }

                                                df->family = (!buffer_string_is_empty(df->host) && NULL != strchr(df->host->ptr, ':')) ? AF_INET6 : AF_INET;
                                        }

                                        if (!buffer_string_is_empty(df->bin_path)) {
                                                /* a local socket + self spawning */
                                                size_t pno;

                                                /* HACK:  just to make sure the adaptive spawing is disabled */
                                                df->min_procs = df->max_procs;

                                                if (df->min_procs > df->max_procs) df->max_procs = df->min_procs;
                                                if (df->max_load_per_proc < 1) df->max_load_per_proc = 0;

                                                if (s->debug) {
                                                        log_error_write(srv, __FILE__, __LINE__, "ssbsdsbsdsd",
                                                                        "--- scgi spawning local",
                                                                        "\n\tproc:", df->bin_path,
                                                                        "\n\tport:", df->port,
                                                                        "\n\tsocket", df->unixsocket,
                                                                        "\n\tmin-procs:", df->min_procs,
                                                                        "\n\tmax-procs:", df->max_procs);
                                                }

                                                for (pno = 0; pno < df->min_procs; pno++) {
                                                        scgi_proc *proc;

                                                        proc = scgi_process_init();
                                                        proc->id = df->num_procs++;
                                                        df->max_id++;

                                                        if (buffer_string_is_empty(df->unixsocket)) {
                                                                proc->port = df->port + pno;
                                                        } else {
                                                                buffer_copy_buffer(proc->socket, df->unixsocket);
                                                                buffer_append_string_len(proc->socket, CONST_STR_LEN("-"));
                                                                buffer_append_int(proc->socket, pno);
                                                        }

                                                        if (s->debug) {
                                                                log_error_write(srv, __FILE__, __LINE__, "ssdsbsdsd",
                                                                                "--- scgi spawning",
                                                                                "\n\tport:", df->port,
                                                                                "\n\tsocket", df->unixsocket,
                                                                                "\n\tcurrent:", pno, "/", df->min_procs);
                                                        }

                                                        if (!srv->srvconf.preflight_check
                                                            && scgi_spawn_connection(srv, p, df, proc)) {
                                                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                                                "[ERROR]: spawning fcgi failed.");
                                                                scgi_process_free(proc);
                                                                goto error;
                                                        }

                                                        proc->next = df->first;
                                                        if (df->first)  df->first->prev = proc;

                                                        df->first = proc;
                                                }
                                        } else {
                                                scgi_proc *fp;

                                                fp = scgi_process_init();
                                                fp->id = df->num_procs++;
                                                df->max_id++;
                                                df->active_procs++;
                                                fp->state = PROC_STATE_RUNNING;

                                                if (buffer_string_is_empty(df->unixsocket)) {
                                                        fp->port = df->port;
                                                } else {
                                                        buffer_copy_buffer(fp->socket, df->unixsocket);
                                                }

                                                df->first = fp;

                                                df->min_procs = 1;
                                                df->max_procs = 1;
                                        }

                                        if (df->xsendfile_docroot->used) {
                                                size_t k;
                                                for (k = 0; k < df->xsendfile_docroot->used; ++k) {
                                                        data_string *ds = (data_string *)df->xsendfile_docroot->data[k];
                                                        if (ds->type != TYPE_STRING) {
                                                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                                        "unexpected type for x-sendfile-docroot; expected: \"x-sendfile-docroot\" => ( \"/allowed/path\", ... )");
                                                                goto error;
                                                        }
                                                        if (ds->value->ptr[0] != '/') {
                                                                log_error_write(srv, __FILE__, __LINE__, "SBs",
                                                                        "x-sendfile-docroot paths must begin with '/'; invalid: \"", ds->value, "\"");
                                                                goto error;
                                                        }
                                                        buffer_path_simplify(ds->value, ds->value);
                                                        buffer_append_slash(ds->value);
                                                }
                                        }

                                        /* if extension already exists, take it */
                                        scgi_extension_insert(s->exts, da_ext->key, df);
                                        df = NULL;
                                }
                        }
                }
        }

        return HANDLER_GO_ON;

error:
        if (NULL != df) scgi_host_free(df);
        return HANDLER_ERROR;
}

static int scgi_set_state(server *srv, handler_ctx *hctx, scgi_connection_state_t state) {
        hctx->state = state;
        hctx->state_timestamp = srv->cur_ts;

        return 0;
}


static void scgi_connection_close(server *srv, handler_ctx *hctx) {
        plugin_data *p;
        connection  *con;

        p    = hctx->plugin_data;
        con  = hctx->remote_conn;

        if (hctx->fd != -1) {
                fdevent_event_del(srv->ev, &(hctx->fde_ndx), hctx->fd);
                fdevent_unregister(srv->ev, hctx->fd);
                close(hctx->fd);
                srv->cur_fds--;
        }

        if (hctx->host && hctx->proc) {
                hctx->host->load--;

                if (hctx->got_proc) {
                        /* after the connect the process gets a load */
                        hctx->proc->load--;

                        if (p->conf.debug) {
                                log_error_write(srv, __FILE__, __LINE__, "sddb",
                                                "release proc:",
                                                hctx->fd,
                                                hctx->proc->pid, hctx->proc->socket);
                        }
                }

                scgi_proclist_sort_down(srv, hctx->host, hctx->proc);
        }


        handler_ctx_free(hctx);
        con->plugin_ctx[p->id] = NULL;

        /* finish response (if not already finished) */
        if (con->mode == p->id
            && (con->state == CON_STATE_HANDLE_REQUEST || con->state == CON_STATE_READ_POST)) {
                /* (not CON_STATE_ERROR and not CON_STATE_RESPONSE_END,
                 *  i.e. not called from scgi_connection_reset()) */

                /* Send an error if we haven't sent any data yet */
                if (0 == con->file_started) {
                        con->http_status = 500;
                        con->mode = DIRECT;
                }
                else if (!con->file_finished) {
                        http_chunk_close(srv, con);
                        con->file_finished = 1;
                }
        }
}

static int scgi_reconnect(server *srv, handler_ctx *hctx) {
        plugin_data *p    = hctx->plugin_data;

        /* child died
         *
         * 1.
         *
         * connect was ok, connection was accepted
         * but the php accept loop checks after the accept if it should die or not.
         *
         * if yes we can only detect it at a write()
         *
         * next step is resetting this attemp and setup a connection again
         *
         * if we have more then 5 reconnects for the same request, die
         *
         * 2.
         *
         * we have a connection but the child died by some other reason
         *
         */

        fdevent_event_del(srv->ev, &(hctx->fde_ndx), hctx->fd);
        fdevent_unregister(srv->ev, hctx->fd);
        close(hctx->fd);
        srv->cur_fds--;

        scgi_set_state(srv, hctx, FCGI_STATE_INIT);

        hctx->request_id = 0;
        hctx->reconnects++;

        if (p->conf.debug) {
                log_error_write(srv, __FILE__, __LINE__, "sddb",
                                "release proc:",
                                hctx->fd,
                                hctx->proc->pid, hctx->proc->socket);
        }

        hctx->proc->load--;
        scgi_proclist_sort_down(srv, hctx->host, hctx->proc);

        return 0;
}


static handler_t scgi_connection_reset(server *srv, connection *con, void *p_d) {
        plugin_data *p = p_d;
        handler_ctx *hctx = con->plugin_ctx[p->id];
        if (hctx) scgi_connection_close(srv, hctx);

        return HANDLER_GO_ON;
}


static int scgi_env_add(buffer *env, const char *key, size_t key_len, const char *val, size_t val_len) {
        size_t len;

        if (!key || !val) return -1;

        len = key_len + val_len + 2;

        buffer_string_prepare_append(env, len);

        buffer_append_string_len(env, key, key_len);
        buffer_append_string_len(env, "", 1);
        buffer_append_string_len(env, val, val_len);
        buffer_append_string_len(env, "", 1);

        return 0;
}


/**
 *
 * returns
 *   -1 error
 *    0 connected
 *    1 not connected yet
 */

static int scgi_establish_connection(server *srv, handler_ctx *hctx) {
        struct sockaddr *scgi_addr;
        struct sockaddr_in scgi_addr_in;
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
        struct sockaddr_in6 scgi_addr_in6;
#endif
#ifdef HAVE_SYS_UN_H
        struct sockaddr_un scgi_addr_un;
#endif
        socklen_t servlen;

        scgi_extension_host *host = hctx->host;
        scgi_proc *proc   = hctx->proc;
        int scgi_fd       = hctx->fd;

        if (!buffer_string_is_empty(proc->socket)) {
#ifdef HAVE_SYS_UN_H
                /* use the unix domain socket */
                memset(&scgi_addr_un, 0, sizeof(scgi_addr_un));
                scgi_addr_un.sun_family = AF_UNIX;
                if (buffer_string_length(proc->socket) + 1 > sizeof(scgi_addr_un.sun_path)) {
                        log_error_write(srv, __FILE__, __LINE__, "sB",
                                        "ERROR: Unix Domain socket filename too long:",
                                        proc->socket);
                        return -1;
                }
                memcpy(scgi_addr_un.sun_path, proc->socket->ptr, buffer_string_length(proc->socket) + 1);

#ifdef SUN_LEN
                servlen = SUN_LEN(&scgi_addr_un);
#else
                /* stevens says: */
                servlen = buffer_string_length(proc->socket) + 1 + sizeof(scgi_addr_un.sun_family);
#endif
                scgi_addr = (struct sockaddr *) &scgi_addr_un;
#else
                return -1;
#endif
#if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
        } else if (host->family == AF_INET6 && !buffer_string_is_empty(host->host)) {
                memset(&scgi_addr_in6, 0, sizeof(scgi_addr_in6));
                scgi_addr_in6.sin6_family = AF_INET6;
                inet_pton(AF_INET6, host->host->ptr, (char *) &scgi_addr_in6.sin6_addr);
                scgi_addr_in6.sin6_port = htons(proc->port);
                servlen = sizeof(scgi_addr_in6);
                scgi_addr = (struct sockaddr *) &scgi_addr_in6;
#endif
        } else {
                memset(&scgi_addr_in, 0, sizeof(scgi_addr_in));
                scgi_addr_in.sin_family = AF_INET;
                if (0 == inet_aton(host->host->ptr, &(scgi_addr_in.sin_addr))) {
                        log_error_write(srv, __FILE__, __LINE__, "sbs",
                                        "converting IP-adress failed for", host->host,
                                        "\nBe sure to specify an IP address here");

                        return -1;
                }
                scgi_addr_in.sin_port = htons(proc->port);
                servlen = sizeof(scgi_addr_in);

                scgi_addr = (struct sockaddr *) &scgi_addr_in;
        }

        if (-1 == connect(scgi_fd, scgi_addr, servlen)) {
                if (errno == EINPROGRESS ||
                    errno == EALREADY ||
                    errno == EINTR) {
                        if (hctx->conf.debug) {
                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                "connect delayed, will continue later:", scgi_fd);
                        }

                        return 1;
                } else {
                        log_error_write(srv, __FILE__, __LINE__, "sdsddb",
                                        "connect failed:", scgi_fd,
                                        strerror(errno), errno,
                                        proc->port, proc->socket);

                        if (errno == EAGAIN) {
                                /* this is Linux only */

                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                "If this happend on Linux: You have been run out of local ports. "
                                                "Check the manual, section Performance how to handle this.");
                        }

                        return -1;
                }
        }
        if (hctx->conf.debug > 1) {
                log_error_write(srv, __FILE__, __LINE__, "sd",
                                "connect succeeded: ", scgi_fd);
        }



        return 0;
}

static int scgi_env_add_request_headers(server *srv, connection *con, plugin_data *p) {
        size_t i;

        for (i = 0; i < con->request.headers->used; i++) {
                data_string *ds;

                ds = (data_string *)con->request.headers->data[i];

                if (!buffer_is_empty(ds->value) && !buffer_is_empty(ds->key)) {
                        buffer_copy_string_encoded_cgi_varnames(srv->tmp_buf, CONST_BUF_LEN(ds->key), 1);

                        scgi_env_add(p->scgi_env, CONST_BUF_LEN(srv->tmp_buf), CONST_BUF_LEN(ds->value));
                }
        }

        for (i = 0; i < con->environment->used; i++) {
                data_string *ds;

                ds = (data_string *)con->environment->data[i];

                if (!buffer_is_empty(ds->value) && !buffer_is_empty(ds->key)) {
                        buffer_copy_string_encoded_cgi_varnames(srv->tmp_buf, CONST_BUF_LEN(ds->key), 0);

                        scgi_env_add(p->scgi_env, CONST_BUF_LEN(srv->tmp_buf), CONST_BUF_LEN(ds->value));
                }
        }

        return 0;
}


static int scgi_create_env(server *srv, handler_ctx *hctx) {
        char buf[LI_ITOSTRING_LENGTH];
        const char *s;
#ifdef HAVE_IPV6
        char b2[INET6_ADDRSTRLEN + 1];
#endif
        buffer *b;

        plugin_data *p    = hctx->plugin_data;
        scgi_extension_host *host= hctx->host;

        connection *con   = hctx->remote_conn;
        server_socket *srv_sock = con->srv_socket;

        sock_addr our_addr;
        socklen_t our_addr_len;

        buffer_string_prepare_copy(p->scgi_env, 1023);

        /* CGI-SPEC 6.1.2, FastCGI spec 6.3 and SCGI spec */

        li_itostrn(buf, sizeof(buf), con->request.content_length);
        scgi_env_add(p->scgi_env, CONST_STR_LEN("CONTENT_LENGTH"), buf, strlen(buf));
        scgi_env_add(p->scgi_env, CONST_STR_LEN("SCGI"), CONST_STR_LEN("1"));


        if (buffer_is_empty(con->conf.server_tag)) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_SOFTWARE"), CONST_STR_LEN(PACKAGE_DESC));
        } else {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_SOFTWARE"), CONST_BUF_LEN(con->conf.server_tag));
        }

        if (!buffer_is_empty(con->server_name)) {
                size_t len = buffer_string_length(con->server_name);

                if (con->server_name->ptr[0] == '[') {
                        const char *colon = strstr(con->server_name->ptr, "]:");
                        if (colon) len = (colon + 1) - con->server_name->ptr;
                } else {
                        const char *colon = strchr(con->server_name->ptr, ':');
                        if (colon) len = colon - con->server_name->ptr;
                }

                scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_NAME"), con->server_name->ptr, len);
        } else {
#ifdef HAVE_IPV6
                s = inet_ntop(srv_sock->addr.plain.sa_family,
                              srv_sock->addr.plain.sa_family == AF_INET6 ?
                              (const void *) &(srv_sock->addr.ipv6.sin6_addr) :
                              (const void *) &(srv_sock->addr.ipv4.sin_addr),
                              b2, sizeof(b2)-1);
#else
                s = inet_ntoa(srv_sock->addr.ipv4.sin_addr);
#endif
                force_assert(s);
                scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_NAME"), s, strlen(s));
        }

        scgi_env_add(p->scgi_env, CONST_STR_LEN("GATEWAY_INTERFACE"), CONST_STR_LEN("CGI/1.1"));

        li_utostrn(buf, sizeof(buf),
#ifdef HAVE_IPV6
               ntohs(srv_sock->addr.plain.sa_family ? srv_sock->addr.ipv6.sin6_port : srv_sock->addr.ipv4.sin_port)
#else
               ntohs(srv_sock->addr.ipv4.sin_port)
#endif
               );

        scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_PORT"), buf, strlen(buf));

        /* get the server-side of the connection to the client */
        our_addr_len = sizeof(our_addr);

        if (-1 == getsockname(con->fd, (struct sockaddr *)&our_addr, &our_addr_len)
            || our_addr_len > sizeof(our_addr)) {
                s = inet_ntop_cache_get_ip(srv, &(srv_sock->addr));
        } else {
                s = inet_ntop_cache_get_ip(srv, &(our_addr));
        }
        scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_ADDR"), s, strlen(s));

        li_utostrn(buf, sizeof(buf),
#ifdef HAVE_IPV6
               ntohs(con->dst_addr.plain.sa_family ? con->dst_addr.ipv6.sin6_port : con->dst_addr.ipv4.sin_port)
#else
               ntohs(con->dst_addr.ipv4.sin_port)
#endif
               );

        scgi_env_add(p->scgi_env, CONST_STR_LEN("REMOTE_PORT"), buf, strlen(buf));

        s = inet_ntop_cache_get_ip(srv, &(con->dst_addr));
        force_assert(s);
        scgi_env_add(p->scgi_env, CONST_STR_LEN("REMOTE_ADDR"), s, strlen(s));

        /*
         * SCRIPT_NAME, PATH_INFO and PATH_TRANSLATED according to
         * http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html
         * (6.1.14, 6.1.6, 6.1.7)
         */

        scgi_env_add(p->scgi_env, CONST_STR_LEN("SCRIPT_NAME"), CONST_BUF_LEN(con->uri.path));

        if (!buffer_string_is_empty(con->request.pathinfo)) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("PATH_INFO"), CONST_BUF_LEN(con->request.pathinfo));

                /* PATH_TRANSLATED is only defined if PATH_INFO is set */

                if (!buffer_string_is_empty(host->docroot)) {
                        buffer_copy_buffer(p->path, host->docroot);
                } else {
                        buffer_copy_buffer(p->path, con->physical.basedir);
                }
                buffer_append_string_buffer(p->path, con->request.pathinfo);
                scgi_env_add(p->scgi_env, CONST_STR_LEN("PATH_TRANSLATED"), CONST_BUF_LEN(p->path));
        } else {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("PATH_INFO"), CONST_STR_LEN(""));
        }

        /*
         * SCRIPT_FILENAME and DOCUMENT_ROOT for php. The PHP manual
         * http://www.php.net/manual/en/reserved.variables.php
         * treatment of PATH_TRANSLATED is different from the one of CGI specs.
         * TODO: this code should be checked against cgi.fix_pathinfo php
         * parameter.
         */

        if (!buffer_string_is_empty(host->docroot)) {
                /*
                 * rewrite SCRIPT_FILENAME
                 *
                 */

                buffer_copy_buffer(p->path, host->docroot);
                buffer_append_string_buffer(p->path, con->uri.path);

                scgi_env_add(p->scgi_env, CONST_STR_LEN("SCRIPT_FILENAME"), CONST_BUF_LEN(p->path));
                scgi_env_add(p->scgi_env, CONST_STR_LEN("DOCUMENT_ROOT"), CONST_BUF_LEN(host->docroot));
        } else {
                buffer_copy_buffer(p->path, con->physical.path);

                scgi_env_add(p->scgi_env, CONST_STR_LEN("SCRIPT_FILENAME"), CONST_BUF_LEN(p->path));
                scgi_env_add(p->scgi_env, CONST_STR_LEN("DOCUMENT_ROOT"), CONST_BUF_LEN(con->physical.basedir));
        }
        if (con->error_handler_saved_status >= 0) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("REQUEST_URI"), CONST_BUF_LEN(con->request.uri));
        } else {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("REQUEST_URI"), CONST_BUF_LEN(con->request.orig_uri));
        }
        if (!buffer_string_is_empty(con->uri.query)) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("QUERY_STRING"), CONST_BUF_LEN(con->uri.query));
        } else {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("QUERY_STRING"), CONST_STR_LEN(""));
        }

        s = get_http_method_name(con->request.http_method);
        force_assert(s);
        scgi_env_add(p->scgi_env, CONST_STR_LEN("REQUEST_METHOD"), s, strlen(s));
        /* set REDIRECT_STATUS for php compiled with --force-redirect
         * (if REDIRECT_STATUS has not already been set by error handler) */
        if (0 == con->error_handler_saved_status) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("REDIRECT_STATUS"), CONST_STR_LEN("200"));
        }
        s = get_http_version_name(con->request.http_version);
        force_assert(s);
        scgi_env_add(p->scgi_env, CONST_STR_LEN("SERVER_PROTOCOL"), s, strlen(s));

#ifdef USE_OPENSSL
        if (buffer_is_equal_caseless_string(con->uri.scheme, CONST_STR_LEN("https"))) {
                scgi_env_add(p->scgi_env, CONST_STR_LEN("HTTPS"), CONST_STR_LEN("on"));
        }
#endif

        scgi_env_add_request_headers(srv, con, p);

        b = buffer_init();

        buffer_append_int(b, buffer_string_length(p->scgi_env));
        buffer_append_string_len(b, CONST_STR_LEN(":"));
        buffer_append_string_buffer(b, p->scgi_env);
        buffer_append_string_len(b, CONST_STR_LEN(","));

        chunkqueue_append_buffer(hctx->wb, b);
        buffer_free(b);

        if (con->request.content_length) {
                chunkqueue *req_cq = con->request_content_queue;

                chunkqueue_steal(hctx->wb, req_cq, req_cq->bytes_in);
        }

        return 0;
}

static int scgi_response_parse(server *srv, connection *con, plugin_data *p, buffer *in, int eol) {
        char *ns;
        const char *s;
        int line = 0;

        UNUSED(srv);

        buffer_copy_buffer(p->parse_response, in);

        for (s = p->parse_response->ptr;
             NULL != (ns = (eol == EOL_RN ? strstr(s, "\r\n") : strchr(s, '\n')));
             s = ns + (eol == EOL_RN ? 2 : 1), line++) {
                const char *key, *value;
                int key_len;
                data_string *ds;

                ns[0] = '\0';

                if (line == 0 &&
                    0 == strncmp(s, "HTTP/1.", 7)) {
                        /* non-parsed header ... we parse them anyway */

                        if ((s[7] == '1' ||
                             s[7] == '0') &&
                            s[8] == ' ') {
                                int status;
                                /* after the space should be a status code for us */

                                status = strtol(s+9, NULL, 10);

                                if (status >= 100 && status < 1000) {
                                        /* we expected 3 digits got them */
                                        con->parsed_response |= HTTP_STATUS;
                                        con->http_status = status;
                                }
                        }
                } else {

                        key = s;
                        if (NULL == (value = strchr(s, ':'))) {
                                /* we expect: "<key>: <value>\r\n" */
                                continue;
                        }

                        key_len = value - key;
                        value += 1;

                        /* skip LWS */
                        while (*value == ' ' || *value == '\t') value++;

                        if (NULL == (ds = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
                                ds = data_response_init();
                        }
                        buffer_copy_string_len(ds->key, key, key_len);
                        buffer_copy_string(ds->value, value);

                        array_insert_unique(con->response.headers, (data_unset *)ds);

                        switch(key_len) {
                        case 4:
                                if (0 == strncasecmp(key, "Date", key_len)) {
                                        con->parsed_response |= HTTP_DATE;
                                }
                                break;
                        case 6:
                                if (0 == strncasecmp(key, "Status", key_len)) {
                                        int status = strtol(value, NULL, 10);
                                        if (status >= 100 && status < 1000) {
                                                con->http_status = status;
                                                con->parsed_response |= HTTP_STATUS;
                                        } else {
                                                con->http_status = 502;
                                        }
                                }
                                break;
                        case 8:
                                if (0 == strncasecmp(key, "Location", key_len)) {
                                        con->parsed_response |= HTTP_LOCATION;
                                }
                                break;
                        case 10:
                                if (0 == strncasecmp(key, "Connection", key_len)) {
                                        con->response.keep_alive = (0 == strcasecmp(value, "Keep-Alive")) ? 1 : 0;
                                        con->parsed_response |= HTTP_CONNECTION;
                                }
                                break;
                        case 14:
                                if (0 == strncasecmp(key, "Content-Length", key_len)) {
                                        con->response.content_length = strtoul(value, NULL, 10);
                                        con->parsed_response |= HTTP_CONTENT_LENGTH;
                                }
                                break;
                        default:
                                break;
                        }
                }
        }

        /* CGI/1.1 rev 03 - 7.2.1.2 */
        if ((con->parsed_response & HTTP_LOCATION) &&
            !(con->parsed_response & HTTP_STATUS)) {
                con->http_status = 302;
        }

        return 0;
}


static int scgi_demux_response(server *srv, handler_ctx *hctx) {
        plugin_data *p    = hctx->plugin_data;
        connection  *con  = hctx->remote_conn;

        while(1) {
                int n;

                buffer_string_prepare_copy(hctx->response, 1023);
                if (-1 == (n = read(hctx->fd, hctx->response->ptr, hctx->response->size - 1))) {
                        if (errno == EAGAIN || errno == EINTR) {
                                /* would block, wait for signal */
                                return 0;
                        }
                        /* error */
                        log_error_write(srv, __FILE__, __LINE__, "sdd", strerror(errno), con->fd, hctx->fd);
                        return -1;
                }

                if (n == 0) {
                        /* read finished */

                        con->file_finished = 1;

                        /* send final chunk */
                        http_chunk_close(srv, con);

                        return 1;
                }

                buffer_commit(hctx->response, n);

                /* split header from body */

                if (con->file_started == 0) {
                        char *c;
                        int in_header = 0;
                        int header_end = 0;
                        int cp, eol = EOL_UNSET;
                        size_t used = 0;
                        size_t hlen = 0;

                        buffer_append_string_buffer(hctx->response_header, hctx->response);

                        /* nph (non-parsed headers) */
                        if (0 == strncmp(hctx->response_header->ptr, "HTTP/1.", 7)) in_header = 1;

                        /* search for the \r\n\r\n or \n\n in the string */
                        for (c = hctx->response_header->ptr, cp = 0, used = buffer_string_length(hctx->response_header); used; c++, cp++, used--) {
                                if (*c == ':') in_header = 1;
                                else if (*c == '\n') {
                                        if (in_header == 0) {
                                                /* got a response without a response header */

                                                c = NULL;
                                                header_end = 1;
                                                break;
                                        }

                                        if (eol == EOL_UNSET) eol = EOL_N;

                                        if (*(c+1) == '\n') {
                                                header_end = 1;
                                                hlen = cp + 2;
                                                break;
                                        }

                                } else if (used > 1 && *c == '\r' && *(c+1) == '\n') {
                                        if (in_header == 0) {
                                                /* got a response without a response header */

                                                c = NULL;
                                                header_end = 1;
                                                break;
                                        }

                                        if (eol == EOL_UNSET) eol = EOL_RN;

                                        if (used > 3 &&
                                            *(c+2) == '\r' &&
                                            *(c+3) == '\n') {
                                                header_end = 1;
                                                hlen = cp + 4;
                                                break;
                                        }

                                        /* skip the \n */
                                        c++;
                                        cp++;
                                        used--;
                                }
                        }

                        if (header_end) {
                                if (c == NULL) {
                                        /* no header, but a body */

                                        if (con->request.http_version == HTTP_VERSION_1_1) {
                                                con->response.transfer_encoding = HTTP_TRANSFER_ENCODING_CHUNKED;
                                        }

                                        http_chunk_append_buffer(srv, con, hctx->response_header);
                                } else {
                                        size_t blen = buffer_string_length(hctx->response_header) - hlen;

                                        /* a small hack: terminate after at the second \r */
                                        buffer_string_set_length(hctx->response_header, hlen - 1);

                                        /* parse the response header */
                                        scgi_response_parse(srv, con, p, hctx->response_header, eol);

                                        if (hctx->host->xsendfile_allow) {
                                                data_string *ds;
                                                if (NULL != (ds = (data_string *) array_get_element(con->response.headers, "X-Sendfile"))) {
                                                        http_response_xsendfile(srv, con, ds->value, hctx->host->xsendfile_docroot);
                                                        return 1;
                                                }
                                        }

                                        /* enable chunked-transfer-encoding */
                                        if (con->request.http_version == HTTP_VERSION_1_1 &&
                                            !(con->parsed_response & HTTP_CONTENT_LENGTH)) {
                                                con->response.transfer_encoding = HTTP_TRANSFER_ENCODING_CHUNKED;
                                        }

                                        if (blen > 0) {
                                                http_chunk_append_mem(srv, con, hctx->response_header->ptr + hlen, blen);
                                        }
                                }

                                con->file_started = 1;
                        }
                } else {
                        http_chunk_append_buffer(srv, con, hctx->response);
                }

#if 0
                log_error_write(srv, __FILE__, __LINE__, "ddss", con->fd, hctx->fd, connection_get_state(con->state), b->ptr);
#endif
        }

        return 0;
}


static int scgi_proclist_sort_up(server *srv, scgi_extension_host *host, scgi_proc *proc) {
        scgi_proc *p;

        UNUSED(srv);

        /* we have been the smallest of the current list
         * and we want to insert the node sorted as soon
         * possible
         *
         * 1 0 0 0 1 1 1
         * |      ^
         * |      |
         * +------+
         *
         */

        /* nothing to sort, only one element */
        if (host->first == proc && proc->next == NULL) return 0;

        for (p = proc; p->next && p->next->load < proc->load; p = p->next);

        /* no need to move something
         *
         * 1 2 2 2 3 3 3
         * ^
         * |
         * +
         *
         */
        if (p == proc) return 0;

        if (host->first == proc) {
                /* we have been the first elememt */

                host->first = proc->next;
                host->first->prev = NULL;
        }

        /* disconnect proc */

        if (proc->prev) proc->prev->next = proc->next;
        if (proc->next) proc->next->prev = proc->prev;

        /* proc should be right of p */

        proc->next = p->next;
        proc->prev = p;
        if (p->next) p->next->prev = proc;
        p->next = proc;
#if 0
        for(p = host->first; p; p = p->next) {
                log_error_write(srv, __FILE__, __LINE__, "dd",
                                p->pid, p->load);
        }
#else
        UNUSED(srv);
#endif

        return 0;
}

int scgi_proclist_sort_down(server *srv, scgi_extension_host *host, scgi_proc *proc) {
        scgi_proc *p;

        UNUSED(srv);

        /* we have been the smallest of the current list
         * and we want to insert the node sorted as soon
         * possible
         *
         *  0 0 0 0 1 0 1
         * ^          |
         * |          |
         * +----------+
         *
         *
         * the basic is idea is:
         * - the last active scgi process should be still
         *   in ram and is not swapped out yet
         * - processes that are not reused will be killed
         *   after some time by the trigger-handler
         * - remember it as:
         *   everything > 0 is hot
         *   all unused procs are colder the more right they are
         *   ice-cold processes are propably unused since more
         *   than 'unused-timeout', are swaped out and won't be
         *   reused in the next seconds anyway.
         *
         */

        /* nothing to sort, only one element */
        if (host->first == proc && proc->next == NULL) return 0;

        for (p = host->first; p != proc && p->load < proc->load; p = p->next);


        /* no need to move something
         *
         * 1 2 2 2 3 3 3
         * ^
         * |
         * +
         *
         */
        if (p == proc) return 0;

        /* we have to move left. If we are already the first element
         * we are done */
        if (host->first == proc) return 0;

        /* release proc */
        if (proc->prev) proc->prev->next = proc->next;
        if (proc->next) proc->next->prev = proc->prev;

        /* proc should be left of p */
        proc->next = p;
        proc->prev = p->prev;
        if (p->prev) p->prev->next = proc;
        p->prev = proc;

        if (proc->prev == NULL) host->first = proc;
#if 0
        for(p = host->first; p; p = p->next) {
                log_error_write(srv, __FILE__, __LINE__, "dd",
                                p->pid, p->load);
        }
#else
        UNUSED(srv);
#endif

        return 0;
}

static int scgi_restart_dead_procs(server *srv, plugin_data *p, scgi_extension_host *host) {
        scgi_proc *proc;

        for (proc = host->first; proc; proc = proc->next) {
                if (p->conf.debug) {
                        log_error_write(srv, __FILE__, __LINE__,  "sbdbdddd",
                                        "proc:",
                                        host->host, proc->port,
                                        proc->socket,
                                        proc->state,
                                        proc->is_local,
                                        proc->load,
                                        proc->pid);
                }

                if (0 == proc->is_local) {
                        /*
                         * external servers might get disabled
                         *
                         * enable the server again, perhaps it is back again
                         */

                        if ((proc->state == PROC_STATE_DISABLED) &&
                            (srv->cur_ts - proc->disable_ts > host->disable_time)) {
                                proc->state = PROC_STATE_RUNNING;
                                host->active_procs++;

                                log_error_write(srv, __FILE__, __LINE__,  "sbdb",
                                                "fcgi-server re-enabled:",
                                                host->host, host->port,
                                                host->unixsocket);
                        }
                } else {
                        /* the child should not terminate at all */
                        int status;

                        if (proc->state == PROC_STATE_DIED_WAIT_FOR_PID) {
                                switch(waitpid(proc->pid, &status, WNOHANG)) {
                                case 0:
                                        /* child is still alive */
                                        break;
                                case -1:
                                        break;
                                default:
                                        if (WIFEXITED(status)) {
#if 0
                                                log_error_write(srv, __FILE__, __LINE__, "sdsd",
                                                                "child exited, pid:", proc->pid,
                                                                "status:", WEXITSTATUS(status));
#endif
                                        } else if (WIFSIGNALED(status)) {
                                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                "child signaled:",
                                                                WTERMSIG(status));
                                        } else {
                                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                "child died somehow:",
                                                                status);
                                        }

                                        proc->state = PROC_STATE_DIED;
                                        break;
                                }
                        }

                        /*
                         * local servers might died, but we restart them
                         *
                         */
                        if (proc->state == PROC_STATE_DIED &&
                            proc->load == 0) {
                                /* restart the child */

                                if (p->conf.debug) {
                                        log_error_write(srv, __FILE__, __LINE__, "ssdsbsdsd",
                                                        "--- scgi spawning",
                                                        "\n\tport:", host->port,
                                                        "\n\tsocket", host->unixsocket,
                                                        "\n\tcurrent:", 1, "/", host->min_procs);
                                }

                                if (scgi_spawn_connection(srv, p, host, proc)) {
                                        log_error_write(srv, __FILE__, __LINE__, "s",
                                                        "ERROR: spawning fcgi failed.");
                                        return HANDLER_ERROR;
                                }

                                scgi_proclist_sort_down(srv, host, proc);
                        }
                }
        }

        return 0;
}


static handler_t scgi_write_request(server *srv, handler_ctx *hctx) {
        plugin_data *p    = hctx->plugin_data;
        scgi_extension_host *host= hctx->host;
        connection *con   = hctx->remote_conn;

        int ret;

        /* sanity check */
        if (!host) {
                log_error_write(srv, __FILE__, __LINE__, "s", "fatal error: host = NULL");
                return HANDLER_ERROR;
        }
        if (((buffer_string_is_empty(host->host) || !host->port) && buffer_string_is_empty(host->unixsocket))) {
                log_error_write(srv, __FILE__, __LINE__, "sxddd",
                                "write-req: error",
                                host,
                                buffer_string_length(host->host),
                                host->port,
                                buffer_string_length(host->unixsocket));
                return HANDLER_ERROR;
        }


        switch(hctx->state) {
        case FCGI_STATE_INIT:
                if (-1 == (hctx->fd = socket(host->family, SOCK_STREAM, 0))) {
                        if (errno == EMFILE ||
                            errno == EINTR) {
                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                "wait for fd at connection:", con->fd);

                                return HANDLER_WAIT_FOR_FD;
                        }

                        log_error_write(srv, __FILE__, __LINE__, "ssdd",
                                        "socket failed:", strerror(errno), srv->cur_fds, srv->max_fds);
                        return HANDLER_ERROR;
                }
                hctx->fde_ndx = -1;

                srv->cur_fds++;

                fdevent_register(srv->ev, hctx->fd, scgi_handle_fdevent, hctx);

                if (-1 == fdevent_fcntl_set(srv->ev, hctx->fd)) {
                        log_error_write(srv, __FILE__, __LINE__, "ss",
                                        "fcntl failed: ", strerror(errno));

                        return HANDLER_ERROR;
                }

                /* fall through */
        case FCGI_STATE_CONNECT:
                if (hctx->state == FCGI_STATE_INIT) {
                        for (hctx->proc = hctx->host->first;
                             hctx->proc && hctx->proc->state != PROC_STATE_RUNNING;
                             hctx->proc = hctx->proc->next);

                        /* all childs are dead */
                        if (hctx->proc == NULL) {
                                hctx->fde_ndx = -1;

                                return HANDLER_ERROR;
                        }

                        if (hctx->proc->is_local) {
                                hctx->pid = hctx->proc->pid;
                        }

                        switch (scgi_establish_connection(srv, hctx)) {
                        case 1:
                                scgi_set_state(srv, hctx, FCGI_STATE_CONNECT);

                                /* connection is in progress, wait for an event and call getsockopt() below */

                                fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);

                                return HANDLER_WAIT_FOR_EVENT;
                        case -1:
                                /* if ECONNREFUSED choose another connection -> FIXME */
                                hctx->fde_ndx = -1;

                                return HANDLER_ERROR;
                        default:
                                /* everything is ok, go on */
                                break;
                        }


                } else {
                        int socket_error;
                        socklen_t socket_error_len = sizeof(socket_error);

                        /* try to finish the connect() */
                        if (0 != getsockopt(hctx->fd, SOL_SOCKET, SO_ERROR, &socket_error, &socket_error_len)) {
                                log_error_write(srv, __FILE__, __LINE__, "ss",
                                                "getsockopt failed:", strerror(errno));

                                return HANDLER_ERROR;
                        }
                        if (socket_error != 0) {
                                if (!hctx->proc->is_local || p->conf.debug) {
                                        /* local procs get restarted */

                                        log_error_write(srv, __FILE__, __LINE__, "ss",
                                                        "establishing connection failed:", strerror(socket_error),
                                                        "port:", hctx->proc->port);
                                }

                                return HANDLER_ERROR;
                        }
                }

                /* ok, we have the connection */

                hctx->proc->load++;
                hctx->proc->last_used = srv->cur_ts;
                hctx->got_proc = 1;

                if (p->conf.debug) {
                        log_error_write(srv, __FILE__, __LINE__, "sddbdd",
                                        "got proc:",
                                        hctx->fd,
                                        hctx->proc->pid,
                                        hctx->proc->socket,
                                        hctx->proc->port,
                                        hctx->proc->load);
                }

                /* move the proc-list entry down the list */
                scgi_proclist_sort_up(srv, hctx->host, hctx->proc);

                scgi_set_state(srv, hctx, FCGI_STATE_PREPARE_WRITE);
                /* fall through */
        case FCGI_STATE_PREPARE_WRITE:
                scgi_create_env(srv, hctx);

                scgi_set_state(srv, hctx, FCGI_STATE_WRITE);

                /* fall through */
        case FCGI_STATE_WRITE:
                ret = srv->network_backend_write(srv, con, hctx->fd, hctx->wb, MAX_WRITE_LIMIT);

                chunkqueue_remove_finished_chunks(hctx->wb);

                if (ret < 0) {
                        if (errno == ENOTCONN || ret == -2) {
                                /* the connection got dropped after accept()
                                 *
                                 * this is most of the time a PHP which dies
                                 * after PHP_FCGI_MAX_REQUESTS
                                 *
                                 */
                                if (hctx->wb->bytes_out == 0 &&
                                    hctx->reconnects < 5) {
                                        usleep(10000); /* take away the load of the webserver
                                                        * to let the php a chance to restart
                                                        */

                                        scgi_reconnect(srv, hctx);

                                        return HANDLER_COMEBACK;
                                }

                                /* not reconnected ... why
                                 *
                                 * far@#lighttpd report this for FreeBSD
                                 *
                                 */

                                log_error_write(srv, __FILE__, __LINE__, "ssosd",
                                                "connection was dropped after accept(). reconnect() denied:",
                                                "write-offset:", hctx->wb->bytes_out,
                                                "reconnect attempts:", hctx->reconnects);

                                return HANDLER_ERROR;
                        } else {
                                /* -1 == ret => error on our side */
                                log_error_write(srv, __FILE__, __LINE__, "ssd",
                                        "write failed:", strerror(errno), errno);

                                return HANDLER_ERROR;
                        }
                }

                if (hctx->wb->bytes_out == hctx->wb->bytes_in) {
                        fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
                        scgi_set_state(srv, hctx, FCGI_STATE_READ);
                } else {
                        fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN|FDEVENT_OUT);
                }

                return HANDLER_WAIT_FOR_EVENT;
        case FCGI_STATE_READ:
                /* waiting for a response */
                return HANDLER_WAIT_FOR_EVENT;
        default:
                log_error_write(srv, __FILE__, __LINE__, "s", "(debug) unknown state");
                return HANDLER_ERROR;
        }
}

static handler_t scgi_send_request(server *srv, handler_ctx *hctx) {
        /* ok, create the request */
        handler_t rc = scgi_write_request(srv, hctx);
        if (HANDLER_ERROR != rc) {
                return rc;
        } else {
                scgi_proc *proc = hctx->proc;
                scgi_extension_host *host = hctx->host;
                plugin_data *p  = hctx->plugin_data;
                connection *con = hctx->remote_conn;

                if (proc &&
                    0 == proc->is_local &&
                    proc->state != PROC_STATE_DISABLED) {
                        /* only disable remote servers as we don't manage them*/

                        log_error_write(srv, __FILE__, __LINE__,  "sbdb", "fcgi-server disabled:",
                                        host->host,
                                        proc->port,
                                        proc->socket);

                        /* disable this server */
                        proc->disable_ts = srv->cur_ts;
                        proc->state = PROC_STATE_DISABLED;
                        host->active_procs--;
                }

                if (hctx->state == FCGI_STATE_INIT ||
                    hctx->state == FCGI_STATE_CONNECT) {
                        /* connect() or getsockopt() failed,
                         * restart the request-handling
                         */
                        if (proc && proc->is_local) {

                                if (p->conf.debug) {
                                        log_error_write(srv, __FILE__, __LINE__,  "sbdb", "connect() to scgi failed, restarting the request-handling:",
                                                        host->host,
                                                        proc->port,
                                                        proc->socket);
                                }

                                /*
                                 * several hctx might reference the same proc
                                 *
                                 * Only one of them should mark the proc as dead all the other
                                 * ones should just take a new one.
                                 *
                                 * If a new proc was started with the old struct this might lead
                                 * the mark a perfect proc as dead otherwise
                                 *
                                 */
                                if (proc->state == PROC_STATE_RUNNING &&
                                    hctx->pid == proc->pid) {
                                        proc->state = PROC_STATE_DIED_WAIT_FOR_PID;
                                }
                        }
                        scgi_restart_dead_procs(srv, p, host);

                        con->mode = DIRECT;/*(avoid changing con->state, con->http_status)*/
                        scgi_connection_close(srv, hctx);
                        con->mode = p->id;

                        return HANDLER_COMEBACK;
                } else {
                        scgi_connection_close(srv, hctx);
                        con->http_status = 503;

                        return HANDLER_FINISHED;
                }
        }
}

SUBREQUEST_FUNC(mod_scgi_handle_subrequest) {
        plugin_data *p = p_d;

        handler_ctx *hctx = con->plugin_ctx[p->id];

        if (NULL == hctx) return HANDLER_GO_ON;

        /* not my job */
        if (con->mode != p->id) return HANDLER_GO_ON;

        if (con->state == CON_STATE_READ_POST) {
                handler_t r = connection_handle_read_post_state(srv, con);
                if (r != HANDLER_GO_ON) return r;
        }

        return (hctx->state != FCGI_STATE_READ)
          ? scgi_send_request(srv, hctx)
          : HANDLER_WAIT_FOR_EVENT;
}


static handler_t scgi_handle_fdevent(server *srv, void *ctx, int revents) {
        handler_ctx *hctx = ctx;
        connection  *con  = hctx->remote_conn;
        plugin_data *p    = hctx->plugin_data;

        scgi_proc *proc   = hctx->proc;
        scgi_extension_host *host= hctx->host;

        joblist_append(srv, con);

        if ((revents & FDEVENT_IN) &&
            hctx->state == FCGI_STATE_READ) {
                switch (scgi_demux_response(srv, hctx)) {
                case 0:
                        break;
                case 1:
                        /* we are done */
                        scgi_connection_close(srv, hctx);

                        return HANDLER_FINISHED;
                case -1:
                        if (proc->pid && proc->state != PROC_STATE_DIED) {
                                int status;

                                /* only fetch the zombie if it is not already done */

                                switch(waitpid(proc->pid, &status, WNOHANG)) {
                                case 0:
                                        /* child is still alive */
                                        break;
                                case -1:
                                        break;
                                default:
                                        /* the child should not terminate at all */
                                        if (WIFEXITED(status)) {
                                                log_error_write(srv, __FILE__, __LINE__, "sdsd",
                                                                "child exited, pid:", proc->pid,
                                                                "status:", WEXITSTATUS(status));
                                        } else if (WIFSIGNALED(status)) {
                                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                "child signaled:",
                                                                WTERMSIG(status));
                                        } else {
                                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                "child died somehow:",
                                                                status);
                                        }

                                        if (p->conf.debug) {
                                                log_error_write(srv, __FILE__, __LINE__, "ssdsbsdsd",
                                                                "--- scgi spawning",
                                                                "\n\tport:", host->port,
                                                                "\n\tsocket", host->unixsocket,
                                                                "\n\tcurrent:", 1, "/", host->min_procs);
                                        }

                                        if (scgi_spawn_connection(srv, p, host, proc)) {
                                                /* child died */
                                                proc->state = PROC_STATE_DIED;
                                        } else {
                                                scgi_proclist_sort_down(srv, host, proc);
                                        }

                                        break;
                                }
                        }

                        if (con->file_started == 0) {
                                /* nothing has been send out yet, try to use another child */

                                if (hctx->wb->bytes_out == 0 &&
                                    hctx->reconnects < 5) {

                                        log_error_write(srv, __FILE__, __LINE__, "ssdsd",
                                                "response not sent, request not sent, reconnection.",
                                                "connection-fd:", con->fd,
                                                "fcgi-fd:", hctx->fd);

                                        scgi_reconnect(srv, hctx);

                                        return HANDLER_COMEBACK;
                                }

                                log_error_write(srv, __FILE__, __LINE__, "sosdsd",
                                                "response not sent, request sent:", hctx->wb->bytes_out,
                                                "connection-fd:", con->fd,
                                                "fcgi-fd:", hctx->fd);

                                scgi_connection_close(srv, hctx);
                        } else {
                                /* response might have been already started, kill the connection */
                                log_error_write(srv, __FILE__, __LINE__, "ssdsd",
                                                "response already sent out, termination connection",
                                                "connection-fd:", con->fd,
                                                "fcgi-fd:", hctx->fd);

                                con->keep_alive = 0;
                                con->file_finished = 1;
                                con->mode = DIRECT; /*(avoid sending final chunked block)*/
                                scgi_connection_close(srv, hctx);
                        }

                        return HANDLER_FINISHED;
                }
        }

        if (revents & FDEVENT_OUT) {
                if (hctx->state == FCGI_STATE_CONNECT ||
                    hctx->state == FCGI_STATE_WRITE) {
                        /* we are allowed to send something out
                         *
                         * 1. in a unfinished connect() call
                         * 2. in a unfinished write() call (long POST request)
                         */
                        return scgi_send_request(srv, hctx); /*(might invalidate hctx)*/
                } else {
                        log_error_write(srv, __FILE__, __LINE__, "sd",
                                        "got a FDEVENT_OUT and didn't know why:",
                                        hctx->state);
                }
        }

        /* perhaps this issue is already handled */
        if (revents & FDEVENT_HUP) {
                if (hctx->state == FCGI_STATE_CONNECT) {
                        /* getoptsock will catch this one (right ?)
                         *
                         * if we are in connect we might get a EINPROGRESS
                         * in the first call and a FDEVENT_HUP in the
                         * second round
                         *
                         * FIXME: as it is a bit ugly.
                         *
                         */
                        scgi_send_request(srv, hctx);
                } else if (hctx->state == FCGI_STATE_READ &&
                           hctx->proc->port == 0) {
                        /* FIXME:
                         *
                         * ioctl says 8192 bytes to read from PHP and we receive directly a HUP for the socket
                         * even if the FCGI_FIN packet is not received yet
                         */
                } else {
                        log_error_write(srv, __FILE__, __LINE__, "sbSBSDSd",
                                        "error: unexpected close of scgi connection for",
                                        con->uri.path,
                                        "(no scgi process on host: ",
                                        host->host,
                                        ", port: ",
                                        host->port,
                                        " ?)",
                                        hctx->state);

                        scgi_connection_close(srv, hctx);
                }
        } else if (revents & FDEVENT_ERR) {
                log_error_write(srv, __FILE__, __LINE__, "s",
                                "fcgi: got a FDEVENT_ERR. Don't know why.");

                if (con->file_started) {
                        con->keep_alive = 0;
                        con->file_finished = 1;
                        con->mode = DIRECT; /*(avoid sending final chunked block)*/
                }
                scgi_connection_close(srv, hctx);
        }

        return HANDLER_FINISHED;
}
#define PATCH(x) \
        p->conf.x = s->x;
static int scgi_patch_connection(server *srv, connection *con, plugin_data *p) {
        size_t i, j;
        plugin_config *s = p->config_storage[0];

        PATCH(exts);
        PATCH(debug);

        /* skip the first, the global context */
        for (i = 1; i < srv->config_context->used; i++) {
                data_config *dc = (data_config *)srv->config_context->data[i];
                s = p->config_storage[i];

                /* condition didn't match */
                if (!config_check_cond(srv, con, dc)) continue;

                /* merge config */
                for (j = 0; j < dc->value->used; j++) {
                        data_unset *du = dc->value->data[j];

                        if (buffer_is_equal_string(du->key, CONST_STR_LEN("scgi.server"))) {
                                PATCH(exts);
                        } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("scgi.debug"))) {
                                PATCH(debug);
                        }
                }
        }

        return 0;
}
#undef PATCH


static handler_t scgi_check_extension(server *srv, connection *con, void *p_d, int uri_path_handler) {
        plugin_data *p = p_d;
        size_t s_len;
        int used = -1;
        size_t k;
        buffer *fn;
        scgi_extension *extension = NULL;
        scgi_extension_host *host = NULL;

        if (con->mode != DIRECT) return HANDLER_GO_ON;

        /* Possibly, we processed already this request */
        if (con->file_started == 1) return HANDLER_GO_ON;

        fn = uri_path_handler ? con->uri.path : con->physical.path;

        if (buffer_string_is_empty(fn)) return HANDLER_GO_ON;

        s_len = buffer_string_length(fn);

        scgi_patch_connection(srv, con, p);

        /* check if extension matches */
        for (k = 0; k < p->conf.exts->used; k++) {
                size_t ct_len;
                scgi_extension *ext = p->conf.exts->exts[k];

                if (buffer_is_empty(ext->key)) continue;

                ct_len = buffer_string_length(ext->key);

                if (s_len < ct_len) continue;

                /* check extension in the form "/scgi_pattern" */
                if (*(ext->key->ptr) == '/') {
                        if (strncmp(fn->ptr, ext->key->ptr, ct_len) == 0) {
                                extension = ext;
                                break;
                        }
                } else if (0 == strncmp(fn->ptr + s_len - ct_len, ext->key->ptr, ct_len)) {
                        /* check extension in the form ".fcg" */
                        extension = ext;
                        break;
                }
        }

        /* extension doesn't match */
        if (NULL == extension) {
                return HANDLER_GO_ON;
        }

        /* get best server */
        for (k = 0; k < extension->used; k++) {
                scgi_extension_host *h = extension->hosts[k];

                /* we should have at least one proc that can do something */
                if (h->active_procs == 0) {
                        continue;
                }

                if (used == -1 || h->load < used) {
                        used = h->load;

                        host = h;
                }
        }

        if (!host) {
                /* sorry, we don't have a server alive for this ext */
                con->http_status = 500;
                con->mode = DIRECT;

                /* only send the 'no handler' once */
                if (!extension->note_is_sent) {
                        extension->note_is_sent = 1;

                        log_error_write(srv, __FILE__, __LINE__, "sbsbs",
                                        "all handlers for ", con->uri.path,
                                        "on", extension->key,
                                        "are down.");
                }

                return HANDLER_FINISHED;
        }

        /* a note about no handler is not sent yet */
        extension->note_is_sent = 0;

        /*
         * if check-local is disabled, use the uri.path handler
         *
         */

        /* init handler-context */
        if (uri_path_handler) {
                if (host->check_local == 0) {
                        handler_ctx *hctx;
                        char *pathinfo;

                        hctx = handler_ctx_init();

                        hctx->remote_conn      = con;
                        hctx->plugin_data      = p;
                        hctx->host             = host;
                        hctx->proc             = NULL;

                        hctx->conf.exts        = p->conf.exts;
                        hctx->conf.debug       = p->conf.debug;

                        con->plugin_ctx[p->id] = hctx;

                        host->load++;

                        con->mode = p->id;

                        if (con->conf.log_request_handling) {
                                log_error_write(srv, __FILE__, __LINE__, "s",
                                "handling it in mod_scgi");
                        }

                        /* the prefix is the SCRIPT_NAME,
                         * everything from start to the next slash
                         * this is important for check-local = "disable"
                         *
                         * if prefix = /admin.fcgi
                         *
                         * /admin.fcgi/foo/bar
                         *
                         * SCRIPT_NAME = /admin.fcgi
                         * PATH_INFO   = /foo/bar
                         *
                         * if prefix = /fcgi-bin/
                         *
                         * /fcgi-bin/foo/bar
                         *
                         * SCRIPT_NAME = /fcgi-bin/foo
                         * PATH_INFO   = /bar
                         *
                         */

                        /* the rewrite is only done for /prefix/? matches */
                        if (host->fix_root_path_name && extension->key->ptr[0] == '/' && extension->key->ptr[1] == '\0') {
                                buffer_copy_string(con->request.pathinfo, con->uri.path->ptr);
                                buffer_string_set_length(con->uri.path, 0);
                        } else if (extension->key->ptr[0] == '/' &&
                            buffer_string_length(con->uri.path) > buffer_string_length(extension->key) &&
                            NULL != (pathinfo = strchr(con->uri.path->ptr + buffer_string_length(extension->key), '/'))) {
                                /* rewrite uri.path and pathinfo */

                                buffer_copy_string(con->request.pathinfo, pathinfo);
                                buffer_string_set_length(con->uri.path, buffer_string_length(con->uri.path) - buffer_string_length(con->request.pathinfo));
                        }
                }
        } else {
                handler_ctx *hctx;
                hctx = handler_ctx_init();

                hctx->remote_conn      = con;
                hctx->plugin_data      = p;
                hctx->host             = host;
                hctx->proc             = NULL;

                hctx->conf.exts        = p->conf.exts;
                hctx->conf.debug       = p->conf.debug;

                con->plugin_ctx[p->id] = hctx;

                host->load++;

                con->mode = p->id;

                if (con->conf.log_request_handling) {
                        log_error_write(srv, __FILE__, __LINE__, "s", "handling it in mod_scgi");
                }
        }

        return HANDLER_GO_ON;
}

/* uri-path handler */
static handler_t scgi_check_extension_1(server *srv, connection *con, void *p_d) {
        return scgi_check_extension(srv, con, p_d, 1);
}

/* start request handler */
static handler_t scgi_check_extension_2(server *srv, connection *con, void *p_d) {
        return scgi_check_extension(srv, con, p_d, 0);
}


TRIGGER_FUNC(mod_scgi_handle_trigger) {
        plugin_data *p = p_d;
        size_t i, j, n;


        /* perhaps we should kill a connect attempt after 10-15 seconds
         *
         * currently we wait for the TCP timeout which is on Linux 180 seconds
         *
         *
         *
         */

        /* check all childs if they are still up */

        for (i = 0; i < srv->config_context->used; i++) {
                plugin_config *conf;
                scgi_exts *exts;

                conf = p->config_storage[i];

                exts = conf->exts;

                for (j = 0; j < exts->used; j++) {
                        scgi_extension *ex;

                        ex = exts->exts[j];

                        for (n = 0; n < ex->used; n++) {

                                scgi_proc *proc;
                                unsigned long sum_load = 0;
                                scgi_extension_host *host;

                                host = ex->hosts[n];

                                scgi_restart_dead_procs(srv, p, host);

                                for (proc = host->first; proc; proc = proc->next) {
                                        sum_load += proc->load;
                                }

                                if (host->num_procs &&
                                    host->num_procs < host->max_procs &&
                                    (sum_load / host->num_procs) > host->max_load_per_proc) {
                                        /* overload, spawn new child */
                                        scgi_proc *fp = NULL;

                                        if (p->conf.debug) {
                                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                                "overload detected, spawning a new child");
                                        }

                                        for (fp = host->unused_procs; fp && fp->pid != 0; fp = fp->next);

                                        if (fp) {
                                                if (fp == host->unused_procs) host->unused_procs = fp->next;

                                                if (fp->next) fp->next->prev = NULL;

                                                host->max_id++;
                                        } else {
                                                fp = scgi_process_init();
                                                fp->id = host->max_id++;
                                        }

                                        host->num_procs++;

                                        if (buffer_string_is_empty(host->unixsocket)) {
                                                fp->port = host->port + fp->id;
                                        } else {
                                                buffer_copy_buffer(fp->socket, host->unixsocket);
                                                buffer_append_string_len(fp->socket, CONST_STR_LEN("-"));
                                                buffer_append_int(fp->socket, fp->id);
                                        }

                                        if (scgi_spawn_connection(srv, p, host, fp)) {
                                                log_error_write(srv, __FILE__, __LINE__, "s",
                                                                "ERROR: spawning fcgi failed.");
                                                scgi_process_free(fp);
                                                return HANDLER_ERROR;
                                        }

                                        fp->prev = NULL;
                                        fp->next = host->first;
                                        if (host->first) {
                                                host->first->prev = fp;
                                        }
                                        host->first = fp;
                                }

                                for (proc = host->first; proc; proc = proc->next) {
                                        if (proc->load != 0) break;
                                        if (host->num_procs <= host->min_procs) break;
                                        if (proc->pid == 0) continue;

                                        if (srv->cur_ts - proc->last_used > host->idle_timeout) {
                                                /* a proc is idling for a long time now,
                                                 * terminated it */

                                                if (p->conf.debug) {
                                                        log_error_write(srv, __FILE__, __LINE__, "ssbsd",
                                                                        "idle-timeout reached, terminating child:",
                                                                        "socket:", proc->socket,
                                                                        "pid", proc->pid);
                                                }


                                                if (proc->next) proc->next->prev = proc->prev;
                                                if (proc->prev) proc->prev->next = proc->next;

                                                if (proc->prev == NULL) host->first = proc->next;

                                                proc->prev = NULL;
                                                proc->next = host->unused_procs;

                                                if (host->unused_procs) host->unused_procs->prev = proc;
                                                host->unused_procs = proc;

                                                kill(proc->pid, SIGTERM);

                                                proc->state = PROC_STATE_KILLED;

                                                log_error_write(srv, __FILE__, __LINE__, "ssbsd",
                                                                        "killed:",
                                                                        "socket:", proc->socket,
                                                                        "pid", proc->pid);

                                                host->num_procs--;

                                                /* proc is now in unused, let the next second handle the next process */
                                                break;
                                        }
                                }

                                for (proc = host->unused_procs; proc; proc = proc->next) {
                                        int status;

                                        if (proc->pid == 0) continue;

                                        switch (waitpid(proc->pid, &status, WNOHANG)) {
                                        case 0:
                                                /* child still running after timeout, good */
                                                break;
                                        case -1:
                                                if (errno != EINTR) {
                                                        /* no PID found ? should never happen */
                                                        log_error_write(srv, __FILE__, __LINE__, "sddss",
                                                                        "pid ", proc->pid, proc->state,
                                                                        "not found:", strerror(errno));

#if 0
                                                        if (errno == ECHILD) {
                                                                /* someone else has cleaned up for us */
                                                                proc->pid = 0;
                                                                proc->state = PROC_STATE_UNSET;
                                                        }
#endif
                                                }
                                                break;
                                        default:
                                                /* the child should not terminate at all */
                                                if (WIFEXITED(status)) {
                                                        if (proc->state != PROC_STATE_KILLED) {
                                                                log_error_write(srv, __FILE__, __LINE__, "sdb",
                                                                                "child exited:",
                                                                                WEXITSTATUS(status), proc->socket);
                                                        }
                                                } else if (WIFSIGNALED(status)) {
                                                        if (WTERMSIG(status) != SIGTERM) {
                                                                log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                                "child signaled:",
                                                                                WTERMSIG(status));
                                                        }
                                                } else {
                                                        log_error_write(srv, __FILE__, __LINE__, "sd",
                                                                        "child died somehow:",
                                                                        status);
                                                }
                                                proc->pid = 0;
                                                proc->state = PROC_STATE_UNSET;
                                                host->max_id--;
                                        }
                                }
                        }
                }
        }

        return HANDLER_GO_ON;
}


int mod_scgi_plugin_init(plugin *p);
int mod_scgi_plugin_init(plugin *p) {
        p->version     = LIGHTTPD_VERSION_ID;
        p->name         = buffer_init_string("scgi");

        p->init         = mod_scgi_init;
        p->cleanup      = mod_scgi_free;
        p->set_defaults = mod_scgi_set_defaults;
        p->connection_reset        = scgi_connection_reset;
        p->handle_connection_close = scgi_connection_reset;
        p->handle_uri_clean        = scgi_check_extension_1;
        p->handle_subrequest_start = scgi_check_extension_2;
        p->handle_subrequest       = mod_scgi_handle_subrequest;
        p->handle_trigger          = mod_scgi_handle_trigger;

        p->data         = NULL;

        return 0;
}