ctdb-scripts: Add default filesystem usage warnings

[Samba.git] / ctdb / common / ctdb_util.c

/* 
   ctdb utility code

   Copyright (C) Andrew Tridgell  2006

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "tdb.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"
#include "../include/ctdb_private.h"

/*
  return error string for last error
*/
const char *ctdb_errstr(struct ctdb_context *ctdb)
{
        return ctdb->err_msg;
}


/*
  remember an error message
*/
void ctdb_set_error(struct ctdb_context *ctdb, const char *fmt, ...)
{
        va_list ap;
        talloc_free(ctdb->err_msg);
        va_start(ap, fmt);
        ctdb->err_msg = talloc_vasprintf(ctdb, fmt, ap);
        DEBUG(DEBUG_ERR,("ctdb error: %s\n", ctdb->err_msg));
        va_end(ap);
}

/*
  a fatal internal error occurred - no hope for recovery
*/
void ctdb_fatal(struct ctdb_context *ctdb, const char *msg)
{
        DEBUG(DEBUG_ALERT,("ctdb fatal error: %s\n", msg));
        abort();
}

/*
  like ctdb_fatal() but a core/backtrace would not be useful
*/
void ctdb_die(struct ctdb_context *ctdb, const char *msg)
{
        DEBUG(DEBUG_ALERT,("ctdb exiting with error: %s\n", msg));
        exit(1);
}

/* Set the path of a helper program from envvar, falling back to
 * dir/file if envvar unset. type is a string to print in log
 * messages.  helper is assumed to point to a statically allocated
 * array of size bytes, initialised to "".  If file is NULL don't fall
 * back if envvar is unset.  If dir is NULL and envvar is unset (but
 * file is not NULL) then this is an error.  Returns true if helper is
 * set, either previously or this time. */
bool ctdb_set_helper(const char *type, char *helper, size_t size,
                     const char *envvar,
                     const char *dir, const char *file)
{
        const char *t;
        struct stat st;

        if (helper[0] != '\0') {
                /* Already set */
                return true;
        }

        t = getenv(envvar);
        if (t != NULL) {
                if (strlen(t) >= size) {
                        DEBUG(DEBUG_ERR,
                              ("Unable to set %s - path too long\n", type));
                        return false;
                }

                strncpy(helper, t, size);
        } else if (file == NULL) {
                return false;
        } else if (dir == NULL) {
                        DEBUG(DEBUG_ERR,
                              ("Unable to set %s - dir is NULL\n", type));
                return false;
        } else {
                if (snprintf(helper, size, "%s/%s", dir, file) >= size) {
                        DEBUG(DEBUG_ERR,
                              ("Unable to set %s - path too long\n", type));
                        return false;
                }
        }

        if (stat(helper, &st) != 0) {
                DEBUG(DEBUG_ERR,
                      ("Unable to set %s \"%s\" - %s\n",
                       type, helper, strerror(errno)));
                return false;
        }
        if (!(st.st_mode & S_IXUSR)) {
                DEBUG(DEBUG_ERR,
                      ("Unable to set %s \"%s\" - not executable\n",
                       type, helper));
                return false;
        }

        DEBUG(DEBUG_NOTICE,
              ("Set %s to \"%s\"\n", type, helper));
        return true;
}

/* Invoke an external program to do some sort of tracing on the CTDB
 * process.  This might block for a little while.  The external
 * program is specified by the environment variable
 * CTDB_EXTERNAL_TRACE.  This program should take one argument: the
 * pid of the process to trace.  Commonly, the program would be a
 * wrapper script around gcore.
 */
void ctdb_external_trace(void)
{
        int ret;
        static char external_trace[PATH_MAX+1] = "";
        char * cmd;

        if (!ctdb_set_helper("external trace handler",
                             external_trace, sizeof(external_trace),
                             "CTDB_EXTERNAL_TRACE", NULL, NULL)) {
                return;
        }

        cmd = talloc_asprintf(NULL, "%s %lu", external_trace, (unsigned long) getpid());
        DEBUG(DEBUG_WARNING,("begin external trace: %s\n", cmd));
        ret = system(cmd);
        if (ret == -1) {
                DEBUG(DEBUG_ERR,
                      ("external trace command \"%s\" failed\n", cmd));
        }
        DEBUG(DEBUG_WARNING,("end external trace: %s\n", cmd));
        talloc_free(cmd);
}

/*
  parse a IP:port pair
*/
int ctdb_parse_address(TALLOC_CTX *mem_ctx, const char *str,
                       ctdb_sock_addr *address)
{
        struct servent *se;
        int port;

        setservent(0);
        se = getservbyname("ctdb", "tcp");
        endservent();

        if (se == NULL) {
                port = CTDB_PORT;
        } else {
                port = ntohs(se->s_port);
        }

        if (! parse_ip(str, NULL, port, address)) {
                return -1;
        }

        return 0;
}


/*
  check if two addresses are the same
*/
bool ctdb_same_address(ctdb_sock_addr *a1, ctdb_sock_addr *a2)
{
        return ctdb_same_ip(a1, a2) &&
                ctdb_addr_to_port(a1) == ctdb_addr_to_port(a2);
}


/*
  hash function for mapping data to a VNN - taken from tdb
*/
uint32_t ctdb_hash(const TDB_DATA *key)
{
        return tdb_jenkins_hash(discard_const(key));
}

/*
  a type checking varient of idr_find
 */
static void *_idr_find_type(struct idr_context *idp, int id, const char *type, const char *location)
{
        void *p = idr_find(idp, id);
        if (p && talloc_check_name(p, type) == NULL) {
                DEBUG(DEBUG_ERR,("%s idr_find_type expected type %s  but got %s\n",
                         location, type, talloc_get_name(p)));
                return NULL;
        }
        return p;
}

uint32_t ctdb_reqid_new(struct ctdb_context *ctdb, void *state)
{
        int id = idr_get_new_above(ctdb->idr, state, ctdb->lastid+1, INT_MAX);
        if (id < 0) {
                DEBUG(DEBUG_DEBUG, ("Reqid wrap!\n"));
                id = idr_get_new(ctdb->idr, state, INT_MAX);
        }
        ctdb->lastid = id;
        return id;
}

void *_ctdb_reqid_find(struct ctdb_context *ctdb, uint32_t reqid, const char *type, const char *location)
{
        void *p;

        p = _idr_find_type(ctdb->idr, reqid, type, location);
        if (p == NULL) {
                DEBUG(DEBUG_WARNING, ("Could not find idr:%u\n",reqid));
        }

        return p;
}


void ctdb_reqid_remove(struct ctdb_context *ctdb, uint32_t reqid)
{
        int ret;

        ret = idr_remove(ctdb->idr, reqid);
        if (ret != 0) {
                DEBUG(DEBUG_ERR, ("Removing idr that does not exist\n"));
        }
}


static uint32_t ctdb_marshall_record_size(TDB_DATA key,
                                          struct ctdb_ltdb_header *header,
                                          TDB_DATA data)
{
        return offsetof(struct ctdb_rec_data, data) + key.dsize +
               data.dsize + (header ? sizeof(*header) : 0);
}

static void ctdb_marshall_record_copy(struct ctdb_rec_data *rec,
                                      uint32_t reqid,
                                      TDB_DATA key,
                                      struct ctdb_ltdb_header *header,
                                      TDB_DATA data,
                                      uint32_t length)
{
        uint32_t offset;

        rec->length = length;
        rec->reqid = reqid;
        rec->keylen = key.dsize;
        memcpy(&rec->data[0], key.dptr, key.dsize);
        offset = key.dsize;

        if (header) {
                rec->datalen = data.dsize + sizeof(*header);
                memcpy(&rec->data[offset], header, sizeof(*header));
                offset += sizeof(*header);
        } else {
                rec->datalen = data.dsize;
        }
        memcpy(&rec->data[offset], data.dptr, data.dsize);
}

/*
  form a ctdb_rec_data record from a key/data pair
  
  note that header may be NULL. If not NULL then it is included in the data portion
  of the record
 */
struct ctdb_rec_data *ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
                                           TDB_DATA key,
                                           struct ctdb_ltdb_header *header,
                                           TDB_DATA data)
{
        size_t length;
        struct ctdb_rec_data *d;

        length = ctdb_marshall_record_size(key, header, data);

        d = (struct ctdb_rec_data *)talloc_size(mem_ctx, length);
        if (d == NULL) {
                return NULL;
        }

        ctdb_marshall_record_copy(d, reqid, key, header, data, length);
        return d;
}


/* helper function for marshalling multiple records */
struct ctdb_marshall_buffer *ctdb_marshall_add(TALLOC_CTX *mem_ctx,
                                               struct ctdb_marshall_buffer *m,
                                               uint64_t db_id,
                                               uint32_t reqid,
                                               TDB_DATA key,
                                               struct ctdb_ltdb_header *header,
                                               TDB_DATA data)
{
        struct ctdb_rec_data *r;
        struct ctdb_marshall_buffer *m2;
        uint32_t length, offset;

        length = ctdb_marshall_record_size(key, header, data);

        if (m == NULL) {
                offset = offsetof(struct ctdb_marshall_buffer, data);
                m2 = talloc_zero_size(mem_ctx, offset + length);
        } else {
                offset = talloc_get_size(m);
                m2 = talloc_realloc_size(mem_ctx, m, offset + length);
        }
        if (m2 == NULL) {
                TALLOC_FREE(m);
                return NULL;
        }

        if (m == NULL) {
                m2->db_id = db_id;
        }

        r = (struct ctdb_rec_data *)((uint8_t *)m2 + offset);
        ctdb_marshall_record_copy(r, reqid, key, header, data, length);
        m2->count++;

        return m2;
}

/* we've finished marshalling, return a data blob with the marshalled records */
TDB_DATA ctdb_marshall_finish(struct ctdb_marshall_buffer *m)
{
        TDB_DATA data;
        data.dptr = (uint8_t *)m;
        data.dsize = talloc_get_size(m);
        return data;
}

/* 
   loop over a marshalling buffer 
   
     - pass r==NULL to start
     - loop the number of times indicated by m->count
*/
struct ctdb_rec_data *ctdb_marshall_loop_next(struct ctdb_marshall_buffer *m, struct ctdb_rec_data *r,
                                              uint32_t *reqid,
                                              struct ctdb_ltdb_header *header,
                                              TDB_DATA *key, TDB_DATA *data)
{
        if (r == NULL) {
                r = (struct ctdb_rec_data *)&m->data[0];
        } else {
                r = (struct ctdb_rec_data *)(r->length + (uint8_t *)r);
        }

        if (reqid != NULL) {
                *reqid = r->reqid;
        }
        
        if (key != NULL) {
                key->dptr   = &r->data[0];
                key->dsize  = r->keylen;
        }
        if (data != NULL) {
                data->dptr  = &r->data[r->keylen];
                data->dsize = r->datalen;
                if (header != NULL) {
                        data->dptr += sizeof(*header);
                        data->dsize -= sizeof(*header);
                }
        }

        if (header != NULL) {
                if (r->datalen < sizeof(*header)) {
                        return NULL;
                }
                memcpy(header, &r->data[r->keylen], sizeof(*header));
        }

        return r;
}

/*
   This is used to canonicalize a ctdb_sock_addr structure.
*/
void ctdb_canonicalize_ip(const ctdb_sock_addr *ip, ctdb_sock_addr *cip)
{
        char prefix[12] = { 0,0,0,0,0,0,0,0,0,0,0xff,0xff };

        memcpy(cip, ip, sizeof (*cip));

        if ( (ip->sa.sa_family == AF_INET6)
        && !memcmp(&ip->ip6.sin6_addr, prefix, 12)) {
                memset(cip, 0, sizeof(*cip));
#ifdef HAVE_SOCK_SIN_LEN
                cip->ip.sin_len = sizeof(*cip);
#endif
                cip->ip.sin_family = AF_INET;
                cip->ip.sin_port   = ip->ip6.sin6_port;
                memcpy(&cip->ip.sin_addr, &ip->ip6.sin6_addr.s6_addr[12], 4);
        }
}

bool ctdb_same_ip(const ctdb_sock_addr *tip1, const ctdb_sock_addr *tip2)
{
        ctdb_sock_addr ip1, ip2;

        ctdb_canonicalize_ip(tip1, &ip1);
        ctdb_canonicalize_ip(tip2, &ip2);
        
        if (ip1.sa.sa_family != ip2.sa.sa_family) {
                return false;
        }

        switch (ip1.sa.sa_family) {
        case AF_INET:
                return ip1.ip.sin_addr.s_addr == ip2.ip.sin_addr.s_addr;
        case AF_INET6:
                return !memcmp(&ip1.ip6.sin6_addr.s6_addr[0],
                                &ip2.ip6.sin6_addr.s6_addr[0],
                                16);
        default:
                DEBUG(DEBUG_ERR, (__location__ " CRITICAL Can not compare sockaddr structures of type %u\n", ip1.sa.sa_family));
                return false;
        }

        return true;
}

/*
  compare two ctdb_sock_addr structures
 */
bool ctdb_same_sockaddr(const ctdb_sock_addr *ip1, const ctdb_sock_addr *ip2)
{
        return ctdb_same_ip(ip1, ip2) && ip1->ip.sin_port == ip2->ip.sin_port;
}

char *ctdb_addr_to_str(ctdb_sock_addr *addr)
{
        static char cip[128] = "";

        switch (addr->sa.sa_family) {
        case AF_INET:
                inet_ntop(addr->ip.sin_family, &addr->ip.sin_addr, cip, sizeof(cip));
                break;
        case AF_INET6:
                inet_ntop(addr->ip6.sin6_family, &addr->ip6.sin6_addr, cip, sizeof(cip));
                break;
        default:
                DEBUG(DEBUG_ERR, (__location__ " ERROR, unknown family %u\n", addr->sa.sa_family));
                ctdb_external_trace();
        }

        return cip;
}

unsigned ctdb_addr_to_port(ctdb_sock_addr *addr)
{
        switch (addr->sa.sa_family) {
        case AF_INET:
                return ntohs(addr->ip.sin_port);
                break;
        case AF_INET6:
                return ntohs(addr->ip6.sin6_port);
                break;
        default:
                DEBUG(DEBUG_ERR, (__location__ " ERROR, unknown family %u\n", addr->sa.sa_family));
        }

        return 0;
}

/* Add a node to a node map with given address and flags */
static bool node_map_add(TALLOC_CTX *mem_ctx,
                         const char *nstr, uint32_t flags,
                         struct ctdb_node_map **node_map)
{
        ctdb_sock_addr addr;
        uint32_t num;
        size_t s;
        struct ctdb_node_and_flags *n;

        /* Might as well do this before trying to allocate memory */
        if (ctdb_parse_address(mem_ctx, nstr, &addr) == -1) {
                return false;
        }

        num = (*node_map)->num + 1;
        s = offsetof(struct ctdb_node_map, nodes) +
                num * sizeof(struct ctdb_node_and_flags);
        *node_map = talloc_realloc_size(mem_ctx, *node_map, s);
        if (*node_map == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
                return false;
        }

        n = &(*node_map)->nodes[(*node_map)->num];
        n->addr = addr;
        n->pnn = (*node_map)->num;
        n->flags = flags;

        (*node_map)->num++;

        return true;
}

/* Read a nodes file into a node map */
struct ctdb_node_map *ctdb_read_nodes_file(TALLOC_CTX *mem_ctx,
                                           const char *nlist)
{
        char **lines;
        int nlines;
        int i;
        struct ctdb_node_map *ret;

        /* Allocate node map header */
        ret = talloc_zero_size(mem_ctx, offsetof(struct ctdb_node_map, nodes));
        if (ret == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Out of memory\n"));
                return false;
        }

        lines = file_lines_load(nlist, &nlines, 0, mem_ctx);
        if (lines == NULL) {
                DEBUG(DEBUG_ERR, ("Failed to read nodes file \"%s\"\n", nlist));
                return false;
        }
        while (nlines > 0 && strcmp(lines[nlines-1], "") == 0) {
                nlines--;
        }

        for (i=0; i < nlines; i++) {
                char *node;
                uint32_t flags;
                size_t len;

                node = lines[i];
                /* strip leading spaces */
                while((*node == ' ') || (*node == '\t')) {
                        node++;
                }

                len = strlen(node);

                while ((len > 1) &&
                       ((node[len-1] == ' ') || (node[len-1] == '\t')))
                {
                        node[len-1] = '\0';
                        len--;
                }

                if (len == 0) {
                        continue;
                }
                if (*node == '#') {
                        /* A "deleted" node is a node that is
                           commented out in the nodes file.  This is
                           used instead of removing a line, which
                           would cause subsequent nodes to change
                           their PNN. */
                        flags = NODE_FLAGS_DELETED;
                        node = discard_const("0.0.0.0");
                } else {
                        flags = 0;
                }
                if (!node_map_add(mem_ctx, node, flags, &ret)) {
                        talloc_free(lines);
                        TALLOC_FREE(ret);
                        return NULL;
                }
        }

        talloc_free(lines);
        return ret;
}

struct ctdb_node_map *
ctdb_node_list_to_map(struct ctdb_node **nodes, uint32_t num_nodes,
                      TALLOC_CTX *mem_ctx)
{
        uint32_t i;
        size_t size;
        struct ctdb_node_map *node_map;

        size = offsetof(struct ctdb_node_map, nodes) +
                num_nodes * sizeof(struct ctdb_node_and_flags);
        node_map  = (struct ctdb_node_map *)talloc_zero_size(mem_ctx, size);
        if (node_map == NULL) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Failed to allocate nodemap array\n"));
                return NULL;
        }

        node_map->num = num_nodes;
        for (i=0; i<num_nodes; i++) {
                node_map->nodes[i].addr  = nodes[i]->address;
                node_map->nodes[i].pnn   = nodes[i]->pnn;
                node_map->nodes[i].flags = nodes[i]->flags;
        }

        return node_map;
}

const char *ctdb_eventscript_call_names[] = {
        "init",
        "setup",
        "startup",
        "startrecovery",
        "recovered",
        "takeip",
        "releaseip",
        "stopped",
        "monitor",
        "status",
        "shutdown",
        "reload",
        "updateip",
        "ipreallocated"
};

/* Runstate handling */
static struct {
        enum ctdb_runstate runstate;
        const char * label;
} runstate_map[] = {
        { CTDB_RUNSTATE_UNKNOWN, "UNKNOWN" },
        { CTDB_RUNSTATE_INIT, "INIT" },
        { CTDB_RUNSTATE_SETUP, "SETUP" },
        { CTDB_RUNSTATE_FIRST_RECOVERY, "FIRST_RECOVERY" },
        { CTDB_RUNSTATE_STARTUP, "STARTUP" },
        { CTDB_RUNSTATE_RUNNING, "RUNNING" },
        { CTDB_RUNSTATE_SHUTDOWN, "SHUTDOWN" },
        { -1, NULL },
};

const char *runstate_to_string(enum ctdb_runstate runstate)
{
        int i;
        for (i=0; runstate_map[i].label != NULL ; i++) {
                if (runstate_map[i].runstate == runstate) {
                        return runstate_map[i].label;
                }
        }

        return runstate_map[0].label;
}

enum ctdb_runstate runstate_from_string(const char *label)
{
        int i;
        for (i=0; runstate_map[i].label != NULL; i++) {
                if (strcasecmp(runstate_map[i].label, label) == 0) {
                        return runstate_map[i].runstate;
                }
        }

        return CTDB_RUNSTATE_UNKNOWN;
}

void ctdb_set_runstate(struct ctdb_context *ctdb, enum ctdb_runstate runstate)
{
        if (runstate <= ctdb->runstate) {
                ctdb_fatal(ctdb, "runstate must always increase");
        }

        DEBUG(DEBUG_NOTICE,("Set runstate to %s (%d)\n",
                            runstate_to_string(runstate), runstate));
        ctdb->runstate = runstate;
}

/* Convert arbitrary data to 4-byte boundary padded uint32 array */
uint32_t *ctdb_key_to_idkey(TALLOC_CTX *mem_ctx, TDB_DATA key)
{
        uint32_t idkey_size, *k;

        idkey_size = 1 + (key.dsize + sizeof(uint32_t)-1) / sizeof(uint32_t);

        k = talloc_zero_array(mem_ctx, uint32_t, idkey_size);
        if (k == NULL) {
                return NULL;
        }

        k[0] = idkey_size;
        memcpy(&k[1], key.dptr, key.dsize);

        return k;
}