src/mod_proxy.c

   1 #include "first.h"
   2
   3 #include "buffer.h"
   4 #include "server.h"
   5 #include "keyvalue.h"
   6 #include "log.h"
   7
   8 #include "http_chunk.h"
   9 #include "fdevent.h"
  10 #include "connections.h"
  11 #include "response.h"
  12 #include "joblist.h"
  13
  14 #include "plugin.h"
  15
  16 #include "inet_ntop_cache.h"
  17 #include "crc32.h"
  18
  19 #include <sys/types.h>
  20
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include <ctype.h>
  27 #include <assert.h>
  28
  29 #include <stdio.h>
  30
  31 #include "sys-socket.h"
  32
  33 #define data_proxy data_fastcgi
  34 #define data_proxy_init data_fastcgi_init
  35
  36 #define PROXY_RETRY_TIMEOUT 60
  37
  38 /**
  39  *
  40  * the proxy module is based on the fastcgi module
  41  *
  42  * 28.06.2004 Jan Kneschke     The first release
  43  * 01.07.2004 Evgeny Rodichev  Several bugfixes and cleanups
  44  *            - co-ordinate up- and downstream flows correctly (proxy_demux_response
  45  *              and proxy_handle_fdevent)
  46  *            - correctly transfer upstream http_response_status;
  47  *            - some unused structures removed.
  48  *
  49  * TODO:      - delay upstream read if write_queue is too large
  50  *              (to prevent memory eating, like in apache). Shoud be
  51  *              configurable).
  52  *            - persistent connection with upstream servers
  53  *            - HTTP/1.1
  54  */
  55 typedef enum {
  56         PROXY_BALANCE_UNSET,
  57         PROXY_BALANCE_FAIR,
  58         PROXY_BALANCE_HASH,
  59         PROXY_BALANCE_RR
  60 } proxy_balance_t;
  61
  62 typedef struct {
  63         array *extensions;
  64         unsigned short debug;
  65
  66         proxy_balance_t balance;
  67 } plugin_config;
  68
  69 typedef struct {
  70         PLUGIN_DATA;
  71
  72         buffer *parse_response;
  73         buffer *balance_buf;
  74
  75         plugin_config **config_storage;
  76
  77         plugin_config conf;
  78 } plugin_data;
  79
  80 typedef enum {
  81         PROXY_STATE_INIT,
  82         PROXY_STATE_CONNECT,
  83         PROXY_STATE_PREPARE_WRITE,
  84         PROXY_STATE_WRITE,
  85         PROXY_STATE_READ
  86 } proxy_connection_state_t;
  87
  88 enum { PROXY_STDOUT, PROXY_END_REQUEST };
  89
  90 typedef struct {
  91         proxy_connection_state_t state;
  92         time_t state_timestamp;
  93
  94         data_proxy *host;
  95
  96         buffer *response;
  97         buffer *response_header;
  98
  99         chunkqueue *wb;
 100         off_t wb_reqlen;
 101
 102         int fd; /* fd to the proxy process */
 103         int fde_ndx; /* index into the fd-event buffer */
 104
 105         size_t path_info_offset; /* start of path_info in uri.path */
 106
 107         connection *remote_conn;  /* dump pointer */
 108         plugin_data *plugin_data; /* dump pointer */
 109 } handler_ctx;
 110
 111
 112 /* ok, we need a prototype */
 113 static handler_t proxy_handle_fdevent(server *srv, void *ctx, int revents);
 114
 115 static handler_ctx * handler_ctx_init(void) {
 116         handler_ctx * hctx;
 117
 118
 119         hctx = calloc(1, sizeof(*hctx));
 120
 121         hctx->state = PROXY_STATE_INIT;
 122         hctx->host = NULL;
 123
 124         hctx->response = buffer_init();
 125         hctx->response_header = buffer_init();
 126
 127         hctx->wb = chunkqueue_init();
 128         hctx->wb_reqlen = 0;
 129
 130         hctx->fd = -1;
 131         hctx->fde_ndx = -1;
 132
 133         return hctx;
 134 }
 135
 136 static void handler_ctx_free(handler_ctx *hctx) {
 137         buffer_free(hctx->response);
 138         buffer_free(hctx->response_header);
 139         chunkqueue_free(hctx->wb);
 140
 141         free(hctx);
 142 }
 143
 144 INIT_FUNC(mod_proxy_init) {
 145         plugin_data *p;
 146
 147         p = calloc(1, sizeof(*p));
 148
 149         p->parse_response = buffer_init();
 150         p->balance_buf = buffer_init();
 151
 152         return p;
 153 }
 154
 155
 156 FREE_FUNC(mod_proxy_free) {
 157         plugin_data *p = p_d;
 158
 159         UNUSED(srv);
 160
 161         buffer_free(p->parse_response);
 162         buffer_free(p->balance_buf);
 163
 164         if (p->config_storage) {
 165                 size_t i;
 166                 for (i = 0; i < srv->config_context->used; i++) {
 167                         plugin_config *s = p->config_storage[i];
 168
 169                         if (NULL == s) continue;
 170
 171                         array_free(s->extensions);
 172
 173                         free(s);
 174                 }
 175                 free(p->config_storage);
 176         }
 177
 178         free(p);
 179
 180         return HANDLER_GO_ON;
 181 }
 182
 183 SETDEFAULTS_FUNC(mod_proxy_set_defaults) {
 184         plugin_data *p = p_d;
 185         data_unset *du;
 186         size_t i = 0;
 187
 188         config_values_t cv[] = {
 189                 { "proxy.server",              NULL, T_CONFIG_LOCAL, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
 190                 { "proxy.debug",               NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
 191                 { "proxy.balance",             NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },      /* 2 */
 192                 { NULL,                        NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
 193         };
 194
 195         p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));
 196
 197         for (i = 0; i < srv->config_context->used; i++) {
 198                 data_config const* config = (data_config const*)srv->config_context->data[i];
 199                 plugin_config *s;
 200
 201                 s = malloc(sizeof(plugin_config));
 202                 s->extensions    = array_init();
 203                 s->debug         = 0;
 204
 205                 cv[0].destination = s->extensions;
 206                 cv[1].destination = &(s->debug);
 207                 cv[2].destination = p->balance_buf;
 208
 209                 buffer_reset(p->balance_buf);
 210
 211                 p->config_storage[i] = s;
 212
 213                 if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
 214                         return HANDLER_ERROR;
 215                 }
 216
 217                 if (buffer_string_is_empty(p->balance_buf)) {
 218                         s->balance = PROXY_BALANCE_FAIR;
 219                 } else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("fair"))) {
 220                         s->balance = PROXY_BALANCE_FAIR;
 221                 } else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("round-robin"))) {
 222                         s->balance = PROXY_BALANCE_RR;
 223                 } else if (buffer_is_equal_string(p->balance_buf, CONST_STR_LEN("hash"))) {
 224                         s->balance = PROXY_BALANCE_HASH;
 225                 } else {
 226                         log_error_write(srv, __FILE__, __LINE__, "sb",
 227                                         "proxy.balance has to be one of: fair, round-robin, hash, but not:", p->balance_buf);
 228                         return HANDLER_ERROR;
 229                 }
 230
 231                 if (NULL != (du = array_get_element(config->value, "proxy.server"))) {
 232                         size_t j;
 233                         data_array *da = (data_array *)du;
 234
 235                         if (du->type != TYPE_ARRAY) {
 236                                 log_error_write(srv, __FILE__, __LINE__, "sss",
 237                                                 "unexpected type for key: ", "proxy.server", "expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
 238
 239                                 return HANDLER_ERROR;
 240                         }
 241
 242                         /*
 243                          * proxy.server = ( "<ext>" => ...,
 244                          *                  "<ext>" => ... )
 245                          */
 246
 247                         for (j = 0; j < da->value->used; j++) {
 248                                 data_array *da_ext = (data_array *)da->value->data[j];
 249                                 size_t n;
 250
 251                                 if (da_ext->type != TYPE_ARRAY) {
 252                                         log_error_write(srv, __FILE__, __LINE__, "sssbs",
 253                                                         "unexpected type for key: ", "proxy.server",
 254                                                         "[", da->value->data[j]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
 255
 256                                         return HANDLER_ERROR;
 257                                 }
 258
 259                                 /*
 260                                  * proxy.server = ( "<ext>" =>
 261                                  *                     ( "<host>" => ( ... ),
 262                                  *                       "<host>" => ( ... )
 263                                  *                     ),
 264                                  *                    "<ext>" => ... )
 265                                  */
 266
 267                                 for (n = 0; n < da_ext->value->used; n++) {
 268                                         data_array *da_host = (data_array *)da_ext->value->data[n];
 269
 270                                         data_proxy *df;
 271                                         data_array *dfa;
 272
 273                                         config_values_t pcv[] = {
 274                                                 { "host",              NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },      /* 0 */
 275                                                 { "port",              NULL, T_CONFIG_SHORT, T_CONFIG_SCOPE_CONNECTION },       /* 1 */
 276                                                 { NULL,                NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
 277                                         };
 278
 279                                         if (da_host->type != TYPE_ARRAY) {
 280                                                 log_error_write(srv, __FILE__, __LINE__, "ssSBS",
 281                                                                 "unexpected type for key:",
 282                                                                 "proxy.server",
 283                                                                 "[", da_ext->value->data[n]->key, "](string); expected ( \"ext\" => ( \"backend-label\" => ( \"key\" => \"value\" )))");
 284
 285                                                 return HANDLER_ERROR;
 286                                         }
 287
 288                                         df = data_proxy_init();
 289
 290                                         df->port = 80;
 291
 292                                         buffer_copy_buffer(df->key, da_host->key);
 293
 294                                         pcv[0].destination = df->host;
 295                                         pcv[1].destination = &(df->port);
 296
 297                                         if (0 != config_insert_values_internal(srv, da_host->value, pcv, T_CONFIG_SCOPE_CONNECTION)) {
 298                                                 df->free((data_unset*) df);
 299                                                 return HANDLER_ERROR;
 300                                         }
 301
 302                                         if (buffer_string_is_empty(df->host)) {
 303                                                 log_error_write(srv, __FILE__, __LINE__, "sbbbs",
 304                                                                 "missing key (string):",
 305                                                                 da->key,
 306                                                                 da_ext->key,
 307                                                                 da_host->key,
 308                                                                 "host");
 309
 310                                                 df->free((data_unset*) df);
 311                                                 return HANDLER_ERROR;
 312                                         }
 313
 314                                         /* if extension already exists, take it */
 315
 316                                         if (NULL == (dfa = (data_array *)array_get_element(s->extensions, da_ext->key->ptr))) {
 317                                                 dfa = data_array_init();
 318
 319                                                 buffer_copy_buffer(dfa->key, da_ext->key);
 320
 321                                                 array_insert_unique(dfa->value, (data_unset *)df);
 322                                                 array_insert_unique(s->extensions, (data_unset *)dfa);
 323                                         } else {
 324                                                 array_insert_unique(dfa->value, (data_unset *)df);
 325                                         }
 326                                 }
 327                         }
 328                 }
 329         }
 330
 331         return HANDLER_GO_ON;
 332 }
 333
 334 static void proxy_connection_close(server *srv, handler_ctx *hctx) {
 335         plugin_data *p;
 336         connection *con;
 337
 338         p    = hctx->plugin_data;
 339         con  = hctx->remote_conn;
 340
 341         if (hctx->fd != -1) {
 342                 fdevent_event_del(srv->ev, &(hctx->fde_ndx), hctx->fd);
 343                 fdevent_unregister(srv->ev, hctx->fd);
 344
 345                 close(hctx->fd);
 346                 srv->cur_fds--;
 347         }
 348
 349         if (hctx->host) {
 350                 hctx->host->usage--;
 351         }
 352
 353         handler_ctx_free(hctx);
 354         con->plugin_ctx[p->id] = NULL;
 355
 356         /* finish response (if not already con->file_started, con->file_finished) */
 357         if (con->mode == p->id) {
 358                 http_response_backend_done(srv, con);
 359         }
 360 }
 361
 362 static int proxy_establish_connection(server *srv, handler_ctx *hctx) {
 363         struct sockaddr *proxy_addr;
 364         struct sockaddr_in proxy_addr_in;
 365 #if defined(HAVE_SYS_UN_H)
 366         struct sockaddr_un proxy_addr_un;
 367 #endif
 368 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
 369         struct sockaddr_in6 proxy_addr_in6;
 370 #endif
 371         socklen_t servlen;
 372
 373         plugin_data *p    = hctx->plugin_data;
 374         data_proxy *host= hctx->host;
 375         int proxy_fd       = hctx->fd;
 376
 377
 378 #if defined(HAVE_SYS_UN_H)
 379         if (strstr(host->host->ptr, "/")) {
 380                 if (buffer_string_length(host->host) + 1 > sizeof(proxy_addr_un.sun_path)) {
 381                         log_error_write(srv, __FILE__, __LINE__, "sB",
 382                                 "ERROR: Unix Domain socket filename too long:",
 383                                 host->host);
 384                         return -1;
 385                 }
 386
 387                 memset(&proxy_addr_un, 0, sizeof(proxy_addr_un));
 388                 proxy_addr_un.sun_family = AF_UNIX;
 389                 memcpy(proxy_addr_un.sun_path, host->host->ptr, buffer_string_length(host->host) + 1);
 390                 servlen = sizeof(proxy_addr_un);
 391                 proxy_addr = (struct sockaddr *) &proxy_addr_un;
 392         } else
 393 #endif
 394 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
 395         if (strstr(host->host->ptr, ":")) {
 396                 memset(&proxy_addr_in6, 0, sizeof(proxy_addr_in6));
 397                 proxy_addr_in6.sin6_family = AF_INET6;
 398                 inet_pton(AF_INET6, host->host->ptr, (char *) &proxy_addr_in6.sin6_addr);
 399                 proxy_addr_in6.sin6_port = htons(host->port);
 400                 servlen = sizeof(proxy_addr_in6);
 401                 proxy_addr = (struct sockaddr *) &proxy_addr_in6;
 402         } else
 403 #endif
 404         {
 405                 memset(&proxy_addr_in, 0, sizeof(proxy_addr_in));
 406                 proxy_addr_in.sin_family = AF_INET;
 407                 proxy_addr_in.sin_addr.s_addr = inet_addr(host->host->ptr);
 408                 proxy_addr_in.sin_port = htons(host->port);
 409                 servlen = sizeof(proxy_addr_in);
 410                 proxy_addr = (struct sockaddr *) &proxy_addr_in;
 411         }
 412
 413
 414         if (-1 == connect(proxy_fd, proxy_addr, servlen)) {
 415                 if (errno == EINPROGRESS || errno == EALREADY) {
 416                         if (p->conf.debug) {
 417                                 log_error_write(srv, __FILE__, __LINE__, "sd",
 418                                                 "connect delayed:", proxy_fd);
 419                         }
 420
 421                         return 1;
 422                 } else {
 423
 424                         log_error_write(srv, __FILE__, __LINE__, "sdsd",
 425                                         "connect failed:", proxy_fd, strerror(errno), errno);
 426
 427                         return -1;
 428                 }
 429         }
 430         if (p->conf.debug) {
 431                 log_error_write(srv, __FILE__, __LINE__, "sd",
 432                                 "connect succeeded: ", proxy_fd);
 433         }
 434
 435         return 0;
 436 }
 437
 438 static void proxy_set_header(connection *con, const char *key, const char *value) {
 439         data_string *ds_dst;
 440
 441         if (NULL == (ds_dst = (data_string *)array_get_unused_element(con->request.headers, TYPE_STRING))) {
 442                 ds_dst = data_string_init();
 443         }
 444
 445         buffer_copy_string(ds_dst->key, key);
 446         buffer_copy_string(ds_dst->value, value);
 447         array_insert_unique(con->request.headers, (data_unset *)ds_dst);
 448 }
 449
 450 static void proxy_append_header(connection *con, const char *key, const char *value) {
 451         data_string *ds_dst;
 452
 453         if (NULL == (ds_dst = (data_string *)array_get_unused_element(con->request.headers, TYPE_STRING))) {
 454                 ds_dst = data_string_init();
 455         }
 456
 457         buffer_copy_string(ds_dst->key, key);
 458         buffer_append_string(ds_dst->value, value);
 459         array_insert_unique(con->request.headers, (data_unset *)ds_dst);
 460 }
 461
 462
 463 static int proxy_create_env(server *srv, handler_ctx *hctx) {
 464         size_t i;
 465
 466         connection *con   = hctx->remote_conn;
 467         buffer *b;
 468
 469         /* build header */
 470
 471         b = buffer_init();
 472
 473         /* request line */
 474         buffer_copy_string(b, get_http_method_name(con->request.http_method));
 475         buffer_append_string_len(b, CONST_STR_LEN(" "));
 476
 477         buffer_append_string_buffer(b, con->request.uri);
 478         buffer_append_string_len(b, CONST_STR_LEN(" HTTP/1.0\r\n"));
 479
 480         proxy_append_header(con, "X-Forwarded-For", (char *)inet_ntop_cache_get_ip(srv, &(con->dst_addr)));
 481         /* http_host is NOT is just a pointer to a buffer
 482          * which is NULL if it is not set */
 483         if (!buffer_string_is_empty(con->request.http_host)) {
 484                 proxy_set_header(con, "X-Host", con->request.http_host->ptr);
 485         }
 486         proxy_set_header(con, "X-Forwarded-Proto", con->uri.scheme->ptr);
 487
 488         /* request header */
 489         for (i = 0; i < con->request.headers->used; i++) {
 490                 data_string *ds;
 491
 492                 ds = (data_string *)con->request.headers->data[i];
 493
 494                 if (!buffer_is_empty(ds->value) && !buffer_is_empty(ds->key)) {
 495                         if (buffer_is_equal_caseless_string(ds->key, CONST_STR_LEN("Connection"))) continue;
 496                         if (buffer_is_equal_caseless_string(ds->key, CONST_STR_LEN("Proxy-Connection"))) continue;
 497
 498                         buffer_append_string_buffer(b, ds->key);
 499                         buffer_append_string_len(b, CONST_STR_LEN(": "));
 500                         buffer_append_string_buffer(b, ds->value);
 501                         buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
 502                 }
 503         }
 504
 505         buffer_append_string_len(b, CONST_STR_LEN("Connection: close\r\n\r\n"));
 506
 507         hctx->wb_reqlen = buffer_string_length(b);
 508         chunkqueue_append_buffer(hctx->wb, b);
 509         buffer_free(b);
 510
 511         /* body */
 512
 513         if (con->request.content_length) {
 514                 chunkqueue_append_chunkqueue(hctx->wb, con->request_content_queue);
 515                 hctx->wb_reqlen += con->request.content_length;/* (eventual) total request size */
 516         }
 517
 518         return 0;
 519 }
 520
 521 static int proxy_set_state(server *srv, handler_ctx *hctx, proxy_connection_state_t state) {
 522         hctx->state = state;
 523         hctx->state_timestamp = srv->cur_ts;
 524
 525         return 0;
 526 }
 527
 528
 529 static int proxy_response_parse(server *srv, connection *con, plugin_data *p, buffer *in) {
 530         char *s, *ns;
 531         int http_response_status = -1;
 532
 533         UNUSED(srv);
 534
 535         /* [\r]\n -> [\0]\0 */
 536
 537         buffer_copy_buffer(p->parse_response, in);
 538
 539         for (s = p->parse_response->ptr; NULL != (ns = strchr(s, '\n')); s = ns + 1) {
 540                 char *key, *value;
 541                 int key_len;
 542                 data_string *ds;
 543                 int copy_header;
 544
 545                 ns[0] = '\0';
 546                 if (s != ns && ns[-1] == '\r') ns[-1] = '\0';
 547
 548                 if (-1 == http_response_status) {
 549                         /* The first line of a Response message is the Status-Line */
 550
 551                         for (key=s; *key && *key != ' '; key++);
 552
 553                         if (*key) {
 554                                 http_response_status = (int) strtol(key, NULL, 10);
 555                                 if (http_response_status < 100 || http_response_status >= 1000) http_response_status = 502;
 556                         } else {
 557                                 http_response_status = 502;
 558                         }
 559
 560                         con->http_status = http_response_status;
 561                         con->parsed_response |= HTTP_STATUS;
 562                         continue;
 563                 }
 564
 565                 if (NULL == (value = strchr(s, ':'))) {
 566                         /* now we expect: "<key>: <value>\n" */
 567
 568                         continue;
 569                 }
 570
 571                 key = s;
 572                 key_len = value - key;
 573
 574                 value++;
 575                 /* strip WS */
 576                 while (*value == ' ' || *value == '\t') value++;
 577
 578                 copy_header = 1;
 579
 580                 switch(key_len) {
 581                 case 4:
 582                         if (0 == strncasecmp(key, "Date", key_len)) {
 583                                 con->parsed_response |= HTTP_DATE;
 584                         }
 585                         break;
 586                 case 8:
 587                         if (0 == strncasecmp(key, "Location", key_len)) {
 588                                 con->parsed_response |= HTTP_LOCATION;
 589                         }
 590                         break;
 591                 case 10:
 592                         if (0 == strncasecmp(key, "Connection", key_len)) {
 593                                 copy_header = 0;
 594                         }
 595                         break;
 596                 case 14:
 597                         if (0 == strncasecmp(key, "Content-Length", key_len)) {
 598                                 con->response.content_length = strtoul(value, NULL, 10);
 599                                 con->parsed_response |= HTTP_CONTENT_LENGTH;
 600                         }
 601                         break;
 602                 default:
 603                         break;
 604                 }
 605
 606                 if (copy_header) {
 607                         if (NULL == (ds = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
 608                                 ds = data_response_init();
 609                         }
 610                         buffer_copy_string_len(ds->key, key, key_len);
 611                         buffer_copy_string(ds->value, value);
 612
 613                         array_insert_unique(con->response.headers, (data_unset *)ds);
 614                 }
 615         }
 616
 617         return 0;
 618 }
 619
 620
 621 static int proxy_demux_response(server *srv, handler_ctx *hctx) {
 622         int fin = 0;
 623         int b;
 624         ssize_t r;
 625
 626         plugin_data *p    = hctx->plugin_data;
 627         connection *con   = hctx->remote_conn;
 628         int proxy_fd       = hctx->fd;
 629
 630         /* check how much we have to read */
 631       #if !defined(_WIN32) && !defined(__CYGWIN__)
 632         if (ioctl(hctx->fd, FIONREAD, &b)) {
 633                 if (errno == EAGAIN) {
 634                         fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
 635                         return 0;
 636                 }
 637                 log_error_write(srv, __FILE__, __LINE__, "sd",
 638                                 "ioctl failed: ",
 639                                 proxy_fd);
 640                 return -1;
 641         }
 642       #else
 643         b = 4096;
 644       #endif
 645
 646
 647         if (p->conf.debug) {
 648                 log_error_write(srv, __FILE__, __LINE__, "sd",
 649                                 "proxy - have to read:", b);
 650         }
 651
 652         if (b > 0) {
 653                 if ((con->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)) {
 654                         off_t cqlen = chunkqueue_length(con->write_queue);
 655                         if (cqlen + b > 65536 - 4096) {
 656                                 if (!con->is_writable) {
 657                                         /*(defer removal of FDEVENT_IN interest since
 658                                          * connection_state_machine() might be able to send data
 659                                          * immediately, unless !con->is_writable, where
 660                                          * connection_state_machine() might not loop back to call
 661                                          * mod_proxy_handle_subrequest())*/
 662                                         fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
 663                                 }
 664                                 if (cqlen >= 65536-1) return 0;
 665                                 b = 65536 - 1 - (int)cqlen;
 666                         }
 667                 }
 668
 669                 buffer_string_prepare_append(hctx->response, b);
 670
 671                 if (-1 == (r = read(hctx->fd, hctx->response->ptr + buffer_string_length(hctx->response), buffer_string_space(hctx->response)))) {
 672                         if (errno == EAGAIN) {
 673                                 fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
 674                                 return 0;
 675                         }
 676                         log_error_write(srv, __FILE__, __LINE__, "sds",
 677                                         "unexpected end-of-file (perhaps the proxy process died):",
 678                                         proxy_fd, strerror(errno));
 679                         return -1;
 680                 }
 681
 682               #if defined(_WIN32) || defined(__CYGWIN__)
 683                 if (0 == r) return 1; /* fin */
 684               #endif
 685
 686                 /* this should be catched by the b > 0 above */
 687                 force_assert(r);
 688
 689                 buffer_commit(hctx->response, r);
 690
 691 #if 0
 692                 log_error_write(srv, __FILE__, __LINE__, "sdsbs",
 693                                 "demux: Response buffer len", hctx->response->used, ":", hctx->response, ":");
 694 #endif
 695
 696                 if (0 == con->got_response) {
 697                         con->got_response = 1;
 698                         buffer_string_prepare_copy(hctx->response_header, 1023);
 699                 }
 700
 701                 if (0 == con->file_started) {
 702                         char *c;
 703
 704                         /* search for the \r\n\r\n in the string */
 705                         if (NULL != (c = buffer_search_string_len(hctx->response, CONST_STR_LEN("\r\n\r\n")))) {
 706                                 size_t hlen = c - hctx->response->ptr + 4;
 707                                 size_t blen = buffer_string_length(hctx->response) - hlen;
 708                                 /* found */
 709
 710                                 buffer_append_string_len(hctx->response_header, hctx->response->ptr, hlen);
 711 #if 0
 712                                 log_error_write(srv, __FILE__, __LINE__, "sb", "Header:", hctx->response_header);
 713 #endif
 714                                 /* parse the response header */
 715                                 proxy_response_parse(srv, con, p, hctx->response_header);
 716
 717                                 con->file_started = 1;
 718                                 if (blen > 0) {
 719                                         if (0 != http_chunk_append_mem(srv, con, c + 4, blen)) {
 720                                                 /* error writing to tempfile;
 721                                                  * truncate response or send 500 if nothing sent yet */
 722                                                 fin = 1;
 723                                                 con->file_started = 0;
 724                                         }
 725                                 }
 726                                 buffer_reset(hctx->response);
 727                         } else {
 728                                 /* no luck, no header found */
 729                                 /*(reuse MAX_HTTP_REQUEST_HEADER as max size for response headers from backends)*/
 730                                 if (buffer_string_length(hctx->response) > MAX_HTTP_REQUEST_HEADER) {
 731                                         log_error_write(srv, __FILE__, __LINE__, "sb", "response headers too large for", con->uri.path);
 732                                         con->http_status = 502; /* Bad Gateway */
 733                                         con->mode = DIRECT;
 734                                         fin = 1;
 735                                 }
 736                         }
 737                 } else {
 738                         if (0 != http_chunk_append_buffer(srv, con, hctx->response)) {
 739                                 /* error writing to tempfile;
 740                                  * truncate response or send 500 if nothing sent yet */
 741                                 fin = 1;
 742                         }
 743                         buffer_reset(hctx->response);
 744                 }
 745         } else {
 746                 /* reading from upstream done */
 747                 fin = 1;
 748         }
 749
 750         return fin;
 751 }
 752
 753
 754 static handler_t proxy_write_request(server *srv, handler_ctx *hctx) {
 755         data_proxy *host= hctx->host;
 756         connection *con   = hctx->remote_conn;
 757
 758         int ret;
 759
 760         if (!host || buffer_string_is_empty(host->host) || !host->port) return HANDLER_ERROR;
 761
 762         switch(hctx->state) {
 763         case PROXY_STATE_CONNECT:
 764                 /* wait for the connect() to finish */
 765
 766                 /* connect failed ? */
 767                 if (-1 == hctx->fde_ndx) return HANDLER_ERROR;
 768
 769                 /* wait */
 770                 return HANDLER_WAIT_FOR_EVENT;
 771
 772         case PROXY_STATE_INIT:
 773 #if defined(HAVE_SYS_UN_H)
 774                 if (strstr(host->host->ptr,"/")) {
 775                         if (-1 == (hctx->fd = socket(AF_UNIX, SOCK_STREAM, 0))) {
 776                                 log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
 777                                 return HANDLER_ERROR;
 778                         }
 779                 } else
 780 #endif
 781 #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
 782                 if (strstr(host->host->ptr,":")) {
 783                         if (-1 == (hctx->fd = socket(AF_INET6, SOCK_STREAM, 0))) {
 784                                 log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
 785                                 return HANDLER_ERROR;
 786                         }
 787                 } else
 788 #endif
 789                 {
 790                         if (-1 == (hctx->fd = socket(AF_INET, SOCK_STREAM, 0))) {
 791                                 log_error_write(srv, __FILE__, __LINE__, "ss", "socket failed: ", strerror(errno));
 792                                 return HANDLER_ERROR;
 793                         }
 794                 }
 795                 hctx->fde_ndx = -1;
 796
 797                 srv->cur_fds++;
 798
 799                 fdevent_register(srv->ev, hctx->fd, proxy_handle_fdevent, hctx);
 800
 801                 if (-1 == fdevent_fcntl_set(srv->ev, hctx->fd)) {
 802                         log_error_write(srv, __FILE__, __LINE__, "ss", "fcntl failed: ", strerror(errno));
 803
 804                         return HANDLER_ERROR;
 805                 }
 806
 807                 switch (proxy_establish_connection(srv, hctx)) {
 808                 case 1:
 809                         proxy_set_state(srv, hctx, PROXY_STATE_CONNECT);
 810
 811                         /* connection is in progress, wait for an event and call getsockopt() below */
 812
 813                         fdevent_event_set(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
 814
 815                         return HANDLER_WAIT_FOR_EVENT;
 816                 case -1:
 817                         /* if ECONNREFUSED choose another connection -> FIXME */
 818                         hctx->fde_ndx = -1;
 819
 820                         return HANDLER_ERROR;
 821                 default:
 822                         /* everything is ok, go on */
 823                         proxy_set_state(srv, hctx, PROXY_STATE_PREPARE_WRITE);
 824                         break;
 825                 }
 826
 827                 /* fall through */
 828
 829         case PROXY_STATE_PREPARE_WRITE:
 830                 proxy_create_env(srv, hctx);
 831
 832                 fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
 833                 proxy_set_state(srv, hctx, PROXY_STATE_WRITE);
 834
 835                 /* fall through */
 836         case PROXY_STATE_WRITE:;
 837                 ret = srv->network_backend_write(srv, con, hctx->fd, hctx->wb, MAX_WRITE_LIMIT);
 838
 839                 chunkqueue_remove_finished_chunks(hctx->wb);
 840
 841                 if (-1 == ret) { /* error on our side */
 842                         log_error_write(srv, __FILE__, __LINE__, "ssd", "write failed:", strerror(errno), errno);
 843
 844                         return HANDLER_ERROR;
 845                 } else if (-2 == ret) { /* remote close */
 846                         log_error_write(srv, __FILE__, __LINE__, "ssd", "write failed, remote connection close:", strerror(errno), errno);
 847
 848                         return HANDLER_ERROR;
 849                 }
 850
 851                 if (hctx->wb->bytes_out == hctx->wb_reqlen) {
 852                         fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
 853                         shutdown(hctx->fd, SHUT_WR);/* future: remove if HTTP/1.1 request */
 854                         proxy_set_state(srv, hctx, PROXY_STATE_READ);
 855                 } else {
 856                         off_t wblen = hctx->wb->bytes_in - hctx->wb->bytes_out;
 857                         if (hctx->wb->bytes_in < hctx->wb_reqlen && wblen < 65536 - 16384) {
 858                                 /*(con->conf.stream_request_body & FDEVENT_STREAM_REQUEST)*/
 859                                 if (!(con->conf.stream_request_body & FDEVENT_STREAM_REQUEST_POLLIN)) {
 860                                         con->conf.stream_request_body |= FDEVENT_STREAM_REQUEST_POLLIN;
 861                                         con->is_readable = 1; /* trigger optimistic read from client */
 862                                 }
 863                         }
 864                         if (0 == wblen) {
 865                                 fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
 866                         } else {
 867                                 fdevent_event_add(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_OUT);
 868                         }
 869                 }
 870
 871                 return HANDLER_WAIT_FOR_EVENT;
 872         case PROXY_STATE_READ:
 873                 /* waiting for a response */
 874                 return HANDLER_WAIT_FOR_EVENT;
 875         default:
 876                 log_error_write(srv, __FILE__, __LINE__, "s", "(debug) unknown state");
 877                 return HANDLER_ERROR;
 878         }
 879 }
 880
 881 #define PATCH(x) \
 882         p->conf.x = s->x;
 883 static int mod_proxy_patch_connection(server *srv, connection *con, plugin_data *p) {
 884         size_t i, j;
 885         plugin_config *s = p->config_storage[0];
 886
 887         PATCH(extensions);
 888         PATCH(debug);
 889         PATCH(balance);
 890
 891         /* skip the first, the global context */
 892         for (i = 1; i < srv->config_context->used; i++) {
 893                 data_config *dc = (data_config *)srv->config_context->data[i];
 894                 s = p->config_storage[i];
 895
 896                 /* condition didn't match */
 897                 if (!config_check_cond(srv, con, dc)) continue;
 898
 899                 /* merge config */
 900                 for (j = 0; j < dc->value->used; j++) {
 901                         data_unset *du = dc->value->data[j];
 902
 903                         if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.server"))) {
 904                                 PATCH(extensions);
 905                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.debug"))) {
 906                                 PATCH(debug);
 907                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("proxy.balance"))) {
 908                                 PATCH(balance);
 909                         }
 910                 }
 911         }
 912
 913         return 0;
 914 }
 915 #undef PATCH
 916
 917 static handler_t proxy_send_request(server *srv, handler_ctx *hctx) {
 918         /* ok, create the request */
 919         handler_t rc = proxy_write_request(srv, hctx);
 920         if (HANDLER_ERROR != rc) {
 921                 return rc;
 922         } else {
 923                 data_proxy *host = hctx->host;
 924                 connection *con  = hctx->remote_conn;
 925                 plugin_data *p   = hctx->plugin_data;
 926                 log_error_write(srv, __FILE__, __LINE__,  "sbdd", "proxy-server disabled:",
 927                                 host->host,
 928                                 host->port,
 929                                 hctx->fd);
 930
 931                 /* disable this server */
 932                 host->is_disabled = 1;
 933                 host->disable_ts = srv->cur_ts;
 934
 935                 /* reset the enviroment and restart the sub-request */
 936                 con->mode = DIRECT;/*(avoid changing con->state, con->http_status)*/
 937                 proxy_connection_close(srv, hctx);
 938                 con->mode = p->id;
 939
 940                 return HANDLER_COMEBACK;
 941         }
 942 }
 943
 944
 945 static handler_t proxy_recv_response(server *srv, handler_ctx *hctx);
 946
 947
 948 SUBREQUEST_FUNC(mod_proxy_handle_subrequest) {
 949         plugin_data *p = p_d;
 950
 951         handler_ctx *hctx = con->plugin_ctx[p->id];
 952
 953         if (NULL == hctx) return HANDLER_GO_ON;
 954
 955         /* not my job */
 956         if (con->mode != p->id) return HANDLER_GO_ON;
 957
 958         if ((con->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
 959             && con->file_started) {
 960                 if (chunkqueue_length(con->write_queue) > 65536 - 4096) {
 961                         fdevent_event_clr(srv->ev, &(hctx->fde_ndx), hctx->fd, FDEVENT_IN);
 962                 } else if (!(fdevent_event_get_interest(srv->ev, hctx->fd) & FDEVENT_IN)) {
 963                         /* optimistic read from backend, which might re-enable FDEVENT_IN */
 964                         handler_t rc = proxy_recv_response(srv, hctx); /*(might invalidate hctx)*/
 965                         if (rc != HANDLER_GO_ON) return rc;            /*(unless HANDLER_GO_ON)*/
 966                 }
 967         }
 968
 969         if (0 == hctx->wb->bytes_in
 970             ? con->state == CON_STATE_READ_POST
 971             : hctx->wb->bytes_in < hctx->wb_reqlen) {
 972                 /*(64k - 4k to attempt to avoid temporary files
 973                  * in conjunction with FDEVENT_STREAM_REQUEST_BUFMIN)*/
 974                 if (hctx->wb->bytes_in - hctx->wb->bytes_out > 65536 - 4096
 975                     && (con->conf.stream_request_body & FDEVENT_STREAM_REQUEST_BUFMIN)){
 976                         con->conf.stream_request_body &= ~FDEVENT_STREAM_REQUEST_POLLIN;
 977                         if (0 != hctx->wb->bytes_in) return HANDLER_WAIT_FOR_EVENT;
 978                 } else {
 979                         handler_t r = connection_handle_read_post_state(srv, con);
 980                         chunkqueue *req_cq = con->request_content_queue;
 981                         if (0 != hctx->wb->bytes_in && !chunkqueue_is_empty(req_cq)) {
 982                                 chunkqueue_append_chunkqueue(hctx->wb, req_cq);
 983                                 if (fdevent_event_get_interest(srv->ev, hctx->fd) & FDEVENT_OUT) {
 984                                         return (r == HANDLER_GO_ON) ? HANDLER_WAIT_FOR_EVENT : r;
 985                                 }
 986                         }
 987                         if (r != HANDLER_GO_ON) return r;
 988                 }
 989         }
 990
 991         return (0 == hctx->wb->bytes_in || !chunkqueue_is_empty(hctx->wb))
 992           ? proxy_send_request(srv, hctx)
 993           : HANDLER_WAIT_FOR_EVENT;
 994 }
 995
 996
 997 static handler_t proxy_recv_response(server *srv, handler_ctx *hctx) {
 998
 999                 switch (proxy_demux_response(srv, hctx)) {
1000                 case 0:
1001                         break;
1002                 case -1:
1003                         http_response_backend_error(srv, hctx->remote_conn);
1004                         /* fall through */
1005                 case 1:
1006                         /* we are done */
1007                         proxy_connection_close(srv, hctx);
1008
1009                         return HANDLER_FINISHED;
1010                 }
1011
1012                 return HANDLER_GO_ON;
1013 }
1014
1015
1016 static handler_t proxy_handle_fdevent(server *srv, void *ctx, int revents) {
1017         handler_ctx *hctx = ctx;
1018         connection  *con  = hctx->remote_conn;
1019         plugin_data *p    = hctx->plugin_data;
1020
1021         joblist_append(srv, con);
1022
1023         if (revents & FDEVENT_IN) {
1024
1025                 if (p->conf.debug) {
1026                         log_error_write(srv, __FILE__, __LINE__, "sd",
1027                                         "proxy: fdevent-in", hctx->state);
1028                 }
1029
1030                 {
1031                 handler_t rc = proxy_recv_response(srv,hctx);/*(might invalidate hctx)*/
1032                 if (rc != HANDLER_GO_ON) return rc;          /*(unless HANDLER_GO_ON)*/
1033                 }
1034         }
1035
1036         if (revents & FDEVENT_OUT) {
1037                 if (p->conf.debug) {
1038                         log_error_write(srv, __FILE__, __LINE__, "sd",
1039                                         "proxy: fdevent-out", hctx->state);
1040                 }
1041
1042                 if (hctx->state == PROXY_STATE_CONNECT) {
1043                         int socket_error;
1044                         socklen_t socket_error_len = sizeof(socket_error);
1045
1046                         /* try to finish the connect() */
1047                         if (0 != getsockopt(hctx->fd, SOL_SOCKET, SO_ERROR, &socket_error, &socket_error_len)) {
1048                                 log_error_write(srv, __FILE__, __LINE__, "ss",
1049                                         "getsockopt failed:", strerror(errno));
1050
1051                                 return HANDLER_FINISHED;
1052                         }
1053                         if (socket_error != 0) {
1054                                 log_error_write(srv, __FILE__, __LINE__, "ss",
1055                                         "establishing connection failed:", strerror(socket_error),
1056                                         "port:", hctx->host->port);
1057
1058                                 return HANDLER_FINISHED;
1059                         }
1060                         if (p->conf.debug) {
1061                                 log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - connect - delayed success");
1062                         }
1063
1064                         proxy_set_state(srv, hctx, PROXY_STATE_PREPARE_WRITE);
1065                 }
1066
1067                 return proxy_send_request(srv, hctx); /*(might invalidate hctx)*/
1068         }
1069
1070         /* perhaps this issue is already handled */
1071         if (revents & FDEVENT_HUP) {
1072                 if (p->conf.debug) {
1073                         log_error_write(srv, __FILE__, __LINE__, "sd",
1074                                         "proxy: fdevent-hup", hctx->state);
1075                 }
1076
1077                 if (hctx->state == PROXY_STATE_CONNECT) {
1078                         /* connect() -> EINPROGRESS -> HUP */
1079
1080                         /**
1081                          * what is proxy is doing if it can't reach the next hop ?
1082                          *
1083                          */
1084
1085                         if (hctx->host) {
1086                                 hctx->host->is_disabled = 1;
1087                                 hctx->host->disable_ts = srv->cur_ts;
1088                                 log_error_write(srv, __FILE__, __LINE__,  "sbdd", "proxy-server disabled:",
1089                                                 hctx->host->host,
1090                                                 hctx->host->port,
1091                                                 hctx->fd);
1092
1093                                 /* disable this server */
1094                                 hctx->host->is_disabled = 1;
1095                                 hctx->host->disable_ts = srv->cur_ts;
1096
1097                                 /* reset the environment and restart the sub-request */
1098                                 con->mode = DIRECT;/*(avoid changing con->state, con->http_status)*/
1099                                 proxy_connection_close(srv, hctx);
1100                                 con->mode = p->id;
1101                         } else {
1102                                 proxy_connection_close(srv, hctx);
1103                                 con->http_status = 503;
1104                         }
1105                 } else if (con->file_started) {
1106                         /* drain any remaining data from kernel pipe buffers
1107                          * even if (con->conf.stream_response_body
1108                          *          & FDEVENT_STREAM_RESPONSE_BUFMIN)
1109                          * since event loop will spin on fd FDEVENT_HUP event
1110                          * until unregistered. */
1111                         handler_t rc;
1112                         do {
1113                                 rc = proxy_recv_response(srv,hctx);/*(might invalidate hctx)*/
1114                         } while (rc == HANDLER_GO_ON);             /*(unless HANDLER_GO_ON)*/
1115                         return rc; /* HANDLER_FINISHED or HANDLER_ERROR */
1116                 } else {
1117                         proxy_connection_close(srv, hctx);
1118                 }
1119         } else if (revents & FDEVENT_ERR) {
1120                 log_error_write(srv, __FILE__, __LINE__, "sd", "proxy-FDEVENT_ERR, but no HUP", revents);
1121
1122                 http_response_backend_error(srv, con);
1123                 proxy_connection_close(srv, hctx);
1124         }
1125
1126         return HANDLER_FINISHED;
1127 }
1128
1129 static handler_t mod_proxy_check_extension(server *srv, connection *con, void *p_d) {
1130         plugin_data *p = p_d;
1131         size_t s_len;
1132         unsigned long last_max = ULONG_MAX;
1133         int max_usage = INT_MAX;
1134         int ndx = -1;
1135         size_t k;
1136         buffer *fn;
1137         data_array *extension = NULL;
1138         size_t path_info_offset;
1139
1140         if (con->mode != DIRECT) return HANDLER_GO_ON;
1141
1142         /* Possibly, we processed already this request */
1143         if (con->file_started == 1) return HANDLER_GO_ON;
1144
1145         mod_proxy_patch_connection(srv, con, p);
1146
1147         fn = con->uri.path;
1148         if (buffer_string_is_empty(fn)) return HANDLER_ERROR;
1149         s_len = buffer_string_length(fn);
1150
1151         path_info_offset = 0;
1152
1153         if (p->conf.debug) {
1154                 log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - start");
1155         }
1156
1157         /* check if extension matches */
1158         for (k = 0; k < p->conf.extensions->used; k++) {
1159                 data_array *ext = NULL;
1160                 size_t ct_len;
1161
1162                 ext = (data_array *)p->conf.extensions->data[k];
1163
1164                 if (buffer_is_empty(ext->key)) continue;
1165
1166                 ct_len = buffer_string_length(ext->key);
1167
1168                 if (s_len < ct_len) continue;
1169
1170                 /* check extension in the form "/proxy_pattern" */
1171                 if (*(ext->key->ptr) == '/') {
1172                         if (strncmp(fn->ptr, ext->key->ptr, ct_len) == 0) {
1173                                 if (s_len > ct_len + 1) {
1174                                         char *pi_offset;
1175
1176                                         if (NULL != (pi_offset = strchr(fn->ptr + ct_len + 1, '/'))) {
1177                                                 path_info_offset = pi_offset - fn->ptr;
1178                                         }
1179                                 }
1180                                 extension = ext;
1181                                 break;
1182                         }
1183                 } else if (0 == strncmp(fn->ptr + s_len - ct_len, ext->key->ptr, ct_len)) {
1184                         /* check extension in the form ".fcg" */
1185                         extension = ext;
1186                         break;
1187                 }
1188         }
1189
1190         if (NULL == extension) {
1191                 return HANDLER_GO_ON;
1192         }
1193
1194         if (p->conf.debug) {
1195                 log_error_write(srv, __FILE__, __LINE__,  "s", "proxy - ext found");
1196         }
1197
1198         if (extension->value->used == 1) {
1199                 if ( ((data_proxy *)extension->value->data[0])->is_disabled ) {
1200                         ndx = -1;
1201                 } else {
1202                         ndx = 0;
1203                 }
1204         } else if (extension->value->used != 0) switch(p->conf.balance) {
1205         case PROXY_BALANCE_HASH:
1206                 /* hash balancing */
1207
1208                 if (p->conf.debug) {
1209                         log_error_write(srv, __FILE__, __LINE__,  "sd",
1210                                         "proxy - used hash balancing, hosts:", extension->value->used);
1211                 }
1212
1213                 for (k = 0, ndx = -1, last_max = ULONG_MAX; k < extension->value->used; k++) {
1214                         data_proxy *host = (data_proxy *)extension->value->data[k];
1215                         unsigned long cur_max;
1216
1217                         if (host->is_disabled) continue;
1218
1219                         cur_max = generate_crc32c(CONST_BUF_LEN(con->uri.path)) +
1220                                 generate_crc32c(CONST_BUF_LEN(host->host)) + /* we can cache this */
1221                                 generate_crc32c(CONST_BUF_LEN(con->uri.authority));
1222
1223                         if (p->conf.debug) {
1224                                 log_error_write(srv, __FILE__, __LINE__,  "sbbbd",
1225                                                 "proxy - election:",
1226                                                 con->uri.path,
1227                                                 host->host,
1228                                                 con->uri.authority,
1229                                                 cur_max);
1230                         }
1231
1232                         if ((last_max == ULONG_MAX) || /* first round */
1233                             (cur_max > last_max)) {
1234                                 last_max = cur_max;
1235
1236                                 ndx = k;
1237                         }
1238                 }
1239
1240                 break;
1241         case PROXY_BALANCE_FAIR:
1242                 /* fair balancing */
1243                 if (p->conf.debug) {
1244                         log_error_write(srv, __FILE__, __LINE__,  "s",
1245                                         "proxy - used fair balancing");
1246                 }
1247
1248                 for (k = 0, ndx = -1, max_usage = INT_MAX; k < extension->value->used; k++) {
1249                         data_proxy *host = (data_proxy *)extension->value->data[k];
1250
1251                         if (host->is_disabled) continue;
1252
1253                         if (host->usage < max_usage) {
1254                                 max_usage = host->usage;
1255
1256                                 ndx = k;
1257                         }
1258                 }
1259
1260                 break;
1261         case PROXY_BALANCE_RR: {
1262                 data_proxy *host;
1263
1264                 /* round robin */
1265                 if (p->conf.debug) {
1266                         log_error_write(srv, __FILE__, __LINE__,  "s",
1267                                         "proxy - used round-robin balancing");
1268                 }
1269
1270                 /* just to be sure */
1271                 force_assert(extension->value->used < INT_MAX);
1272
1273                 host = (data_proxy *)extension->value->data[0];
1274
1275                 /* Use last_used_ndx from first host in list */
1276                 k = host->last_used_ndx;
1277                 ndx = k + 1; /* use next host after the last one */
1278                 if (ndx < 0) ndx = 0;
1279
1280                 /* Search first active host after last_used_ndx */
1281                 while ( ndx < (int) extension->value->used
1282                                 && (host = (data_proxy *)extension->value->data[ndx])->is_disabled ) ndx++;
1283
1284                 if (ndx >= (int) extension->value->used) {
1285                         /* didn't found a higher id, wrap to the start */
1286                         for (ndx = 0; ndx <= (int) k; ndx++) {
1287                                 host = (data_proxy *)extension->value->data[ndx];
1288                                 if (!host->is_disabled) break;
1289                         }
1290
1291                         /* No active host found */
1292                         if (host->is_disabled) ndx = -1;
1293                 }
1294
1295                 /* Save new index for next round */
1296                 ((data_proxy *)extension->value->data[0])->last_used_ndx = ndx;
1297
1298                 break;
1299         }
1300         default:
1301                 break;
1302         }
1303
1304         /* found a server */
1305         if (ndx != -1) {
1306                 data_proxy *host = (data_proxy *)extension->value->data[ndx];
1307
1308                 /*
1309                  * if check-local is disabled, use the uri.path handler
1310                  *
1311                  */
1312
1313                 /* init handler-context */
1314                 handler_ctx *hctx;
1315                 hctx = handler_ctx_init();
1316
1317                 hctx->path_info_offset = path_info_offset;
1318                 hctx->remote_conn      = con;
1319                 hctx->plugin_data      = p;
1320                 hctx->host             = host;
1321
1322                 con->plugin_ctx[p->id] = hctx;
1323
1324                 host->usage++;
1325
1326                 con->mode = p->id;
1327
1328                 if (p->conf.debug) {
1329                         log_error_write(srv, __FILE__, __LINE__,  "sbd",
1330                                         "proxy - found a host",
1331                                         host->host, host->port);
1332                 }
1333
1334                 return HANDLER_GO_ON;
1335         } else {
1336                 /* no handler found */
1337                 con->http_status = 500;
1338
1339                 log_error_write(srv, __FILE__, __LINE__,  "sb",
1340                                 "no proxy-handler found for:",
1341                                 fn);
1342
1343                 return HANDLER_FINISHED;
1344         }
1345         return HANDLER_GO_ON;
1346 }
1347
1348 static handler_t mod_proxy_connection_reset(server *srv, connection *con, void *p_d) {
1349         plugin_data *p = p_d;
1350         handler_ctx *hctx = con->plugin_ctx[p->id];
1351         if (hctx) proxy_connection_close(srv, hctx);
1352
1353         return HANDLER_GO_ON;
1354 }
1355
1356 /**
1357  *
1358  * the trigger re-enables the disabled connections after the timeout is over
1359  *
1360  * */
1361
1362 TRIGGER_FUNC(mod_proxy_trigger) {
1363         plugin_data *p = p_d;
1364
1365         if (p->config_storage) {
1366                 size_t i, n, k;
1367                 for (i = 0; i < srv->config_context->used; i++) {
1368                         plugin_config *s = p->config_storage[i];
1369
1370                         if (!s) continue;
1371
1372                         /* get the extensions for all configs */
1373
1374                         for (k = 0; k < s->extensions->used; k++) {
1375                                 data_array *extension = (data_array *)s->extensions->data[k];
1376
1377                                 /* get all hosts */
1378                                 for (n = 0; n < extension->value->used; n++) {
1379                                         data_proxy *host = (data_proxy *)extension->value->data[n];
1380
1381                                         if (!host->is_disabled ||
1382                                             srv->cur_ts - host->disable_ts < 5) continue;
1383
1384                                         log_error_write(srv, __FILE__, __LINE__,  "sbd",
1385                                                         "proxy - re-enabled:",
1386                                                         host->host, host->port);
1387
1388                                         host->is_disabled = 0;
1389                                 }
1390                         }
1391                 }
1392         }
1393
1394         return HANDLER_GO_ON;
1395 }
1396
1397
1398 int mod_proxy_plugin_init(plugin *p);
1399 int mod_proxy_plugin_init(plugin *p) {
1400         p->version      = LIGHTTPD_VERSION_ID;
1401         p->name         = buffer_init_string("proxy");
1402
1403         p->init         = mod_proxy_init;
1404         p->cleanup      = mod_proxy_free;
1405         p->set_defaults = mod_proxy_set_defaults;
1406         p->connection_reset        = mod_proxy_connection_reset; /* end of req-resp cycle */
1407         p->handle_connection_close = mod_proxy_connection_reset; /* end of client connection */
1408         p->handle_uri_clean        = mod_proxy_check_extension;
1409         p->handle_subrequest       = mod_proxy_handle_subrequest;
1410         p->handle_trigger          = mod_proxy_trigger;
1411
1412         p->data         = NULL;
1413
1414         return 0;
1415 }