client.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include <libubox/blobmsg.h>
  21 #include <ctype.h>
  22
  23 #include "uhttpd.h"
  24 #include "tls.h"
  25
  26 static LIST_HEAD(clients);
  27
  28 int n_clients = 0;
  29 struct config conf = {};
  30
  31 const char * const http_versions[] = {
  32         [UH_HTTP_VER_0_9] = "HTTP/0.9",
  33         [UH_HTTP_VER_1_0] = "HTTP/1.0",
  34         [UH_HTTP_VER_1_1] = "HTTP/1.1",
  35 };
  36
  37 const char * const http_methods[] = {
  38         [UH_HTTP_MSG_GET] = "GET",
  39         [UH_HTTP_MSG_POST] = "POST",
  40         [UH_HTTP_MSG_HEAD] = "HEAD",
  41 };
  42
  43 void uh_http_header(struct client *cl, int code, const char *summary)
  44 {
  45         struct http_request *r = &cl->request;
  46         const char *enc = "Transfer-Encoding: chunked\r\n";
  47         const char *conn;
  48
  49         if (!uh_use_chunked(cl))
  50                 enc = "";
  51
  52         if (r->connection_close)
  53                 conn = "Connection: close";
  54         else
  55                 conn = "Connection: Keep-Alive";
  56
  57         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  58                 http_versions[cl->request.version],
  59                 code, summary, conn, enc);
  60
  61         if (!r->connection_close)
  62                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
  63 }
  64
  65 static void uh_connection_close(struct client *cl)
  66 {
  67         cl->state = CLIENT_STATE_CLOSE;
  68         cl->us->eof = true;
  69         ustream_state_change(cl->us);
  70 }
  71
  72 static void uh_dispatch_done(struct client *cl)
  73 {
  74         if (cl->dispatch.free)
  75                 cl->dispatch.free(cl);
  76         if (cl->dispatch.req_free)
  77                 cl->dispatch.req_free(cl);
  78 }
  79
  80 static void client_timeout(struct uloop_timeout *timeout)
  81 {
  82         struct client *cl = container_of(timeout, struct client, timeout);
  83
  84         cl->state = CLIENT_STATE_CLOSE;
  85         uh_connection_close(cl);
  86 }
  87
  88 static void uh_set_client_timeout(struct client *cl, int timeout)
  89 {
  90         cl->timeout.cb = client_timeout;
  91         uloop_timeout_set(&cl->timeout, timeout * 1000);
  92 }
  93
  94 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
  95 {
  96         struct client *cl = container_of(timeout, struct client, timeout);
  97         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
  98
  99         uh_set_client_timeout(cl, sec);
 100         cl->us->notify_read(cl->us, 0);
 101 }
 102
 103 static void uh_poll_connection(struct client *cl)
 104 {
 105         cl->timeout.cb = uh_keepalive_poll_cb;
 106         uloop_timeout_set(&cl->timeout, 1);
 107 }
 108
 109 void uh_request_done(struct client *cl)
 110 {
 111         uh_chunk_eof(cl);
 112         uh_dispatch_done(cl);
 113         cl->us->notify_write = NULL;
 114         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 115
 116         if (!conf.http_keepalive || cl->request.connection_close)
 117                 return uh_connection_close(cl);
 118
 119         cl->state = CLIENT_STATE_INIT;
 120         cl->requests++;
 121         uh_poll_connection(cl);
 122 }
 123
 124 void __printf(4, 5)
 125 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 126 {
 127         va_list arg;
 128
 129         uh_http_header(cl, code, summary);
 130         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 131
 132         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 133
 134         if (fmt) {
 135                 va_start(arg, fmt);
 136                 uh_chunk_vprintf(cl, fmt, arg);
 137                 va_end(arg);
 138         }
 139
 140         uh_request_done(cl);
 141 }
 142
 143 static void uh_header_error(struct client *cl, int code, const char *summary)
 144 {
 145         uh_client_error(cl, code, summary, NULL);
 146         uh_connection_close(cl);
 147 }
 148
 149 static int find_idx(const char * const *list, int max, const char *str)
 150 {
 151         int i;
 152
 153         for (i = 0; i < max; i++)
 154                 if (!strcmp(list[i], str))
 155                         return i;
 156
 157         return -1;
 158 }
 159
 160 static int client_parse_request(struct client *cl, char *data)
 161 {
 162         struct http_request *req = &cl->request;
 163         char *type, *path, *version;
 164         int h_method, h_version;
 165
 166         type = strtok(data, " ");
 167         path = strtok(NULL, " ");
 168         version = strtok(NULL, " ");
 169         if (!type || !path || !version)
 170                 return CLIENT_STATE_DONE;
 171
 172         blobmsg_add_string(&cl->hdr, "URL", path);
 173
 174         memset(&cl->request, 0, sizeof(cl->request));
 175         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 176         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 177         if (h_method < 0 || h_version < 0) {
 178                 req->version = UH_HTTP_VER_1_0;
 179                 return CLIENT_STATE_DONE;
 180         }
 181
 182         req->method = h_method;
 183         req->version = h_version;
 184         if (req->version < UH_HTTP_VER_1_1 || !conf.http_keepalive)
 185                 req->connection_close = true;
 186
 187         return CLIENT_STATE_HEADER;
 188 }
 189
 190 static bool client_init_cb(struct client *cl, char *buf, int len)
 191 {
 192         char *newline;
 193
 194         newline = strstr(buf, "\r\n");
 195         if (!newline)
 196                 return false;
 197
 198         if (newline == buf)
 199                 return true;
 200
 201         *newline = 0;
 202         blob_buf_init(&cl->hdr, 0);
 203         cl->state = client_parse_request(cl, buf);
 204         ustream_consume(cl->us, newline + 2 - buf);
 205         if (cl->state == CLIENT_STATE_DONE)
 206                 uh_header_error(cl, 400, "Bad Request");
 207
 208         return true;
 209 }
 210
 211 static bool rfc1918_filter_check(struct client *cl)
 212 {
 213         if (!conf.rfc1918_filter)
 214                 return true;
 215
 216         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 217                 return true;
 218
 219         uh_client_error(cl, 403, "Forbidden",
 220                         "Rejected request from RFC1918 IP "
 221                         "to public server address");
 222         return false;
 223 }
 224
 225 static void client_header_complete(struct client *cl)
 226 {
 227         struct http_request *r = &cl->request;
 228
 229         if (!rfc1918_filter_check(cl))
 230                 return;
 231
 232         if (r->expect_cont)
 233                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 234
 235         switch(r->ua) {
 236         case UH_UA_MSIE_OLD:
 237                 if (r->method != UH_HTTP_MSG_POST)
 238                         break;
 239
 240                 /* fall through */
 241         case UH_UA_SAFARI:
 242                 r->connection_close = true;
 243                 break;
 244         default:
 245                 break;
 246         }
 247
 248         uh_handle_request(cl);
 249 }
 250
 251 static void client_parse_header(struct client *cl, char *data)
 252 {
 253         struct http_request *r = &cl->request;
 254         char *err;
 255         char *name;
 256         char *val;
 257
 258         if (!*data) {
 259                 uloop_timeout_cancel(&cl->timeout);
 260                 cl->state = CLIENT_STATE_DATA;
 261                 client_header_complete(cl);
 262                 return;
 263         }
 264
 265         val = uh_split_header(data);
 266         if (!val) {
 267                 cl->state = CLIENT_STATE_DONE;
 268                 return;
 269         }
 270
 271         for (name = data; *name; name++)
 272                 if (isupper(*name))
 273                         *name = tolower(*name);
 274
 275         if (!strcmp(data, "expect")) {
 276                 if (!strcasecmp(val, "100-continue"))
 277                         r->expect_cont = true;
 278                 else {
 279                         uh_header_error(cl, 412, "Precondition Failed");
 280                         return;
 281                 }
 282         } else if (!strcmp(data, "content-length")) {
 283                 r->content_length = strtoul(val, &err, 0);
 284                 if (err && *err) {
 285                         uh_header_error(cl, 400, "Bad Request");
 286                         return;
 287                 }
 288         } else if (!strcmp(data, "transfer-encoding")) {
 289                 if (!strcmp(val, "chunked"))
 290                         r->transfer_chunked = true;
 291         } else if (!strcmp(data, "connection")) {
 292                 if (!strcasecmp(val, "close"))
 293                         r->connection_close = true;
 294                 else if (!strcasecmp(val, "keep-alive"))
 295                         r->connection_close = false;
 296         } else if (!strcmp(data, "user-agent")) {
 297                 char *str;
 298
 299                 if (strstr(val, "Opera"))
 300                         r->ua = UH_UA_OPERA;
 301                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 302                         r->ua = UH_UA_MSIE_NEW;
 303                         if (str[5] && str[6] == '.') {
 304                                 switch (str[5]) {
 305                                 case '6':
 306                                         if (strstr(str, "SV1"))
 307                                                 break;
 308                                         /* fall through */
 309                                 case '5':
 310                                 case '4':
 311                                         r->ua = UH_UA_MSIE_OLD;
 312                                         break;
 313                                 }
 314                         }
 315                 } else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 316                         r->ua = UH_UA_SAFARI;
 317                 else if (strstr(val, "Chrome/"))
 318                         r->ua = UH_UA_CHROME;
 319                 else if (strstr(val, "Gecko/"))
 320                         r->ua = UH_UA_GECKO;
 321                 else if (strstr(val, "Konqueror"))
 322                         r->ua = UH_UA_KONQUEROR;
 323         }
 324
 325
 326         blobmsg_add_string(&cl->hdr, data, val);
 327
 328         cl->state = CLIENT_STATE_HEADER;
 329 }
 330
 331 void client_poll_post_data(struct client *cl)
 332 {
 333         struct dispatch *d = &cl->dispatch;
 334         struct http_request *r = &cl->request;
 335         char *buf;
 336         int len;
 337
 338         if (cl->state == CLIENT_STATE_DONE)
 339                 return;
 340
 341         while (1) {
 342                 char *sep;
 343                 int offset = 0;
 344                 int cur_len;
 345
 346                 buf = ustream_get_read_buf(cl->us, &len);
 347                 if (!buf || !len)
 348                         break;
 349
 350                 if (!d->data_send)
 351                         return;
 352
 353                 cur_len = min(r->content_length, len);
 354                 if (cur_len) {
 355                         if (d->data_blocked)
 356                                 break;
 357
 358                         if (d->data_send)
 359                                 cur_len = d->data_send(cl, buf, cur_len);
 360
 361                         r->content_length -= cur_len;
 362                         ustream_consume(cl->us, cur_len);
 363                         continue;
 364                 }
 365
 366                 if (!r->transfer_chunked)
 367                         break;
 368
 369                 if (r->transfer_chunked > 1)
 370                         offset = 2;
 371
 372                 sep = strstr(buf + offset, "\r\n");
 373                 if (!sep)
 374                         break;
 375
 376                 *sep = 0;
 377
 378                 r->content_length = strtoul(buf + offset, &sep, 16);
 379                 r->transfer_chunked++;
 380                 ustream_consume(cl->us, sep + 2 - buf);
 381
 382                 /* invalid chunk length */
 383                 if (sep && *sep) {
 384                         r->content_length = 0;
 385                         r->transfer_chunked = 0;
 386                         break;
 387                 }
 388
 389                 /* empty chunk == eof */
 390                 if (!r->content_length) {
 391                         r->transfer_chunked = false;
 392                         break;
 393                 }
 394         }
 395
 396         buf = ustream_get_read_buf(cl->us, &len);
 397         if (!r->content_length && !r->transfer_chunked &&
 398                 cl->state != CLIENT_STATE_DONE) {
 399                 if (cl->dispatch.data_done)
 400                         cl->dispatch.data_done(cl);
 401
 402                 cl->state = CLIENT_STATE_DONE;
 403         }
 404 }
 405
 406 static bool client_data_cb(struct client *cl, char *buf, int len)
 407 {
 408         client_poll_post_data(cl);
 409         return false;
 410 }
 411
 412 static bool client_header_cb(struct client *cl, char *buf, int len)
 413 {
 414         char *newline;
 415         int line_len;
 416
 417         newline = strstr(buf, "\r\n");
 418         if (!newline)
 419                 return false;
 420
 421         *newline = 0;
 422         client_parse_header(cl, buf);
 423         line_len = newline + 2 - buf;
 424         ustream_consume(cl->us, line_len);
 425         if (cl->state == CLIENT_STATE_DATA)
 426                 return client_data_cb(cl, newline + 2, len - line_len);
 427
 428         return true;
 429 }
 430
 431 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 432 static read_cb_t read_cbs[] = {
 433         [CLIENT_STATE_INIT] = client_init_cb,
 434         [CLIENT_STATE_HEADER] = client_header_cb,
 435         [CLIENT_STATE_DATA] = client_data_cb,
 436 };
 437
 438 void uh_client_read_cb(struct client *cl)
 439 {
 440         struct ustream *us = cl->us;
 441         char *str;
 442         int len;
 443
 444         do {
 445                 str = ustream_get_read_buf(us, &len);
 446                 if (!str || !len)
 447                         break;
 448
 449                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 450                         break;
 451
 452                 if (!read_cbs[cl->state](cl, str, len)) {
 453                         if (len == us->r.buffer_len &&
 454                             cl->state != CLIENT_STATE_DATA)
 455                                 uh_header_error(cl, 413, "Request Entity Too Large");
 456                         break;
 457                 }
 458         } while(1);
 459 }
 460
 461 static void client_close(struct client *cl)
 462 {
 463         n_clients--;
 464         uh_dispatch_done(cl);
 465         uloop_timeout_cancel(&cl->timeout);
 466         if (cl->tls)
 467                 uh_tls_client_detach(cl);
 468         ustream_free(&cl->sfd.stream);
 469         close(cl->sfd.fd.fd);
 470         list_del(&cl->list);
 471         blob_buf_free(&cl->hdr);
 472         free(cl);
 473
 474         uh_unblock_listeners();
 475 }
 476
 477 void uh_client_notify_state(struct client *cl)
 478 {
 479         struct ustream *s = cl->us;
 480
 481         if (!s->write_error) {
 482                 if (cl->state == CLIENT_STATE_DATA)
 483                         return;
 484
 485                 if (!s->eof || s->w.data_bytes)
 486                         return;
 487         }
 488
 489         return client_close(cl);
 490 }
 491
 492 static void client_ustream_read_cb(struct ustream *s, int bytes)
 493 {
 494         struct client *cl = container_of(s, struct client, sfd.stream);
 495
 496         uh_client_read_cb(cl);
 497 }
 498
 499 static void client_ustream_write_cb(struct ustream *s, int bytes)
 500 {
 501         struct client *cl = container_of(s, struct client, sfd.stream);
 502
 503         if (cl->dispatch.write_cb)
 504                 cl->dispatch.write_cb(cl);
 505 }
 506
 507 static void client_notify_state(struct ustream *s)
 508 {
 509         struct client *cl = container_of(s, struct client, sfd.stream);
 510
 511         uh_client_notify_state(cl);
 512 }
 513
 514 static void set_addr(struct uh_addr *addr, void *src)
 515 {
 516         struct sockaddr_in *sin = src;
 517         struct sockaddr_in6 *sin6 = src;
 518
 519         addr->family = sin->sin_family;
 520         if (addr->family == AF_INET) {
 521                 addr->port = ntohs(sin->sin_port);
 522                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 523         } else {
 524                 addr->port = ntohs(sin6->sin6_port);
 525                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 526         }
 527 }
 528
 529 bool uh_accept_client(int fd, bool tls)
 530 {
 531         static struct client *next_client;
 532         struct client *cl;
 533         unsigned int sl;
 534         int sfd;
 535         static int client_id = 0;
 536         struct sockaddr_in6 addr;
 537
 538         if (!next_client)
 539                 next_client = calloc(1, sizeof(*next_client));
 540
 541         cl = next_client;
 542
 543         sl = sizeof(addr);
 544         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 545         if (sfd < 0)
 546                 return false;
 547
 548         set_addr(&cl->peer_addr, &addr);
 549         sl = sizeof(addr);
 550         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 551         set_addr(&cl->srv_addr, &addr);
 552
 553         cl->us = &cl->sfd.stream;
 554         if (tls) {
 555                 uh_tls_client_attach(cl);
 556         } else {
 557                 cl->us->notify_read = client_ustream_read_cb;
 558                 cl->us->notify_write = client_ustream_write_cb;
 559                 cl->us->notify_state = client_notify_state;
 560         }
 561
 562         cl->us->string_data = true;
 563         ustream_fd_init(&cl->sfd, sfd);
 564
 565         uh_poll_connection(cl);
 566         list_add_tail(&cl->list, &clients);
 567
 568         next_client = NULL;
 569         n_clients++;
 570         cl->id = client_id++;
 571
 572         return true;
 573 }
 574
 575 void uh_close_fds(void)
 576 {
 577         struct client *cl;
 578
 579         uloop_done();
 580         uh_close_listen_fds();
 581         list_for_each_entry(cl, &clients, list) {
 582                 close(cl->sfd.fd.fd);
 583                 if (cl->dispatch.close_fds)
 584                         cl->dispatch.close_fds(cl);
 585         }
 586 }