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 static bool client_done = false;
  28
  29 int n_clients = 0;
  30 struct config conf = {};
  31
  32 const char * const http_versions[] = {
  33         [UH_HTTP_VER_0_9] = "HTTP/0.9",
  34         [UH_HTTP_VER_1_0] = "HTTP/1.0",
  35         [UH_HTTP_VER_1_1] = "HTTP/1.1",
  36 };
  37
  38 const char * const http_methods[] = {
  39         [UH_HTTP_MSG_GET] = "GET",
  40         [UH_HTTP_MSG_POST] = "POST",
  41         [UH_HTTP_MSG_HEAD] = "HEAD",
  42         [UH_HTTP_MSG_OPTIONS] = "OPTIONS",
  43 };
  44
  45 void uh_http_header(struct client *cl, int code, const char *summary)
  46 {
  47         struct http_request *r = &cl->request;
  48         const char *enc = "Transfer-Encoding: chunked\r\n";
  49         const char *conn;
  50
  51         cl->http_code = code;
  52
  53         if (!cl->request.respond_chunked)
  54                 enc = "";
  55
  56         if (r->connection_close)
  57                 conn = "Connection: close";
  58         else
  59                 conn = "Connection: Keep-Alive";
  60
  61         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  62                 http_versions[cl->request.version],
  63                 code, summary, conn, enc);
  64
  65         if (!r->connection_close)
  66                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
  67 }
  68
  69 static void uh_connection_close(struct client *cl)
  70 {
  71         cl->state = CLIENT_STATE_CLOSE;
  72         cl->us->eof = true;
  73         ustream_state_change(cl->us);
  74 }
  75
  76 static void uh_dispatch_done(struct client *cl)
  77 {
  78         if (cl->dispatch.free)
  79                 cl->dispatch.free(cl);
  80         if (cl->dispatch.req_free)
  81                 cl->dispatch.req_free(cl);
  82 }
  83
  84 static void client_timeout(struct uloop_timeout *timeout)
  85 {
  86         struct client *cl = container_of(timeout, struct client, timeout);
  87
  88         cl->state = CLIENT_STATE_CLOSE;
  89         uh_connection_close(cl);
  90 }
  91
  92 static void uh_set_client_timeout(struct client *cl, int timeout)
  93 {
  94         cl->timeout.cb = client_timeout;
  95         uloop_timeout_set(&cl->timeout, timeout * 1000);
  96 }
  97
  98 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
  99 {
 100         struct client *cl = container_of(timeout, struct client, timeout);
 101         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
 102
 103         uh_set_client_timeout(cl, sec);
 104         cl->us->notify_read(cl->us, 0);
 105 }
 106
 107 static void uh_poll_connection(struct client *cl)
 108 {
 109         cl->timeout.cb = uh_keepalive_poll_cb;
 110         uloop_timeout_set(&cl->timeout, 1);
 111 }
 112
 113 void uh_request_done(struct client *cl)
 114 {
 115         uh_chunk_eof(cl);
 116         uh_dispatch_done(cl);
 117         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 118
 119         if (!conf.http_keepalive || cl->request.connection_close)
 120                 return uh_connection_close(cl);
 121
 122         cl->state = CLIENT_STATE_INIT;
 123         cl->requests++;
 124         uh_poll_connection(cl);
 125 }
 126
 127 void __printf(4, 5)
 128 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 129 {
 130         va_list arg;
 131
 132         uh_http_header(cl, code, summary);
 133         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 134
 135         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 136
 137         if (fmt) {
 138                 va_start(arg, fmt);
 139                 uh_chunk_vprintf(cl, fmt, arg);
 140                 va_end(arg);
 141         }
 142
 143         uh_request_done(cl);
 144 }
 145
 146 static void uh_header_error(struct client *cl, int code, const char *summary)
 147 {
 148         uh_client_error(cl, code, summary, NULL);
 149         uh_connection_close(cl);
 150 }
 151
 152 static int find_idx(const char * const *list, int max, const char *str)
 153 {
 154         int i;
 155
 156         for (i = 0; i < max; i++)
 157                 if (!strcmp(list[i], str))
 158                         return i;
 159
 160         return -1;
 161 }
 162
 163 static int client_parse_request(struct client *cl, char *data)
 164 {
 165         struct http_request *req = &cl->request;
 166         char *type, *path, *version;
 167         int h_method, h_version;
 168
 169         type = strtok(data, " ");
 170         path = strtok(NULL, " ");
 171         version = strtok(NULL, " ");
 172         if (!type || !path || !version)
 173                 return CLIENT_STATE_DONE;
 174
 175         blobmsg_add_string(&cl->hdr, "URL", path);
 176
 177         memset(&cl->request, 0, sizeof(cl->request));
 178         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 179         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 180         if (h_method < 0 || h_version < 0) {
 181                 req->version = UH_HTTP_VER_1_0;
 182                 return CLIENT_STATE_DONE;
 183         }
 184
 185         req->method = h_method;
 186         req->version = h_version;
 187         if (req->version < UH_HTTP_VER_1_1 || req->method == UH_HTTP_MSG_POST ||
 188             !conf.http_keepalive)
 189                 req->connection_close = true;
 190
 191         req->respond_chunked = uh_use_chunked(cl);
 192
 193         return CLIENT_STATE_HEADER;
 194 }
 195
 196 static bool client_init_cb(struct client *cl, char *buf, int len)
 197 {
 198         char *newline;
 199
 200         newline = strstr(buf, "\r\n");
 201         if (!newline)
 202                 return false;
 203
 204         if (newline == buf) {
 205                 ustream_consume(cl->us, 2);
 206                 return true;
 207         }
 208
 209         *newline = 0;
 210         blob_buf_init(&cl->hdr, 0);
 211         cl->state = client_parse_request(cl, buf);
 212         ustream_consume(cl->us, newline + 2 - buf);
 213         if (cl->state == CLIENT_STATE_DONE)
 214                 uh_header_error(cl, 400, "Bad Request");
 215
 216         return true;
 217 }
 218
 219 static bool rfc1918_filter_check(struct client *cl)
 220 {
 221         if (!conf.rfc1918_filter)
 222                 return true;
 223
 224         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 225                 return true;
 226
 227         uh_client_error(cl, 403, "Forbidden",
 228                         "Rejected request from RFC1918 IP "
 229                         "to public server address");
 230         return false;
 231 }
 232
 233 static bool tls_redirect_check(struct client *cl)
 234 {
 235         int rem, port;
 236         struct blob_attr *cur;
 237         char *ptr, *url = NULL, *host = NULL;
 238
 239         if (cl->tls || !conf.tls_redirect)
 240                 return true;
 241
 242         if ((port = uh_first_tls_port(cl->srv_addr.family)) == -1)
 243                 return true;
 244
 245         blob_for_each_attr(cur, cl->hdr.head, rem) {
 246                 if (!strcmp(blobmsg_name(cur), "host"))
 247                         host = blobmsg_get_string(cur);
 248
 249                 if (!strcmp(blobmsg_name(cur), "URL"))
 250                         url = blobmsg_get_string(cur);
 251
 252                 if (url && host)
 253                         break;
 254         }
 255
 256         if (!url || !host)
 257                 return true;
 258
 259         if ((ptr = strchr(host, ']')) != NULL)
 260                 *(ptr+1) = 0;
 261         else if ((ptr = strchr(host, ':')) != NULL)
 262                 *ptr = 0;
 263
 264         cl->request.respond_chunked = false;
 265         cl->request.connection_close = true;
 266
 267         uh_http_header(cl, 307, "Temporary Redirect");
 268
 269         if (port != 443)
 270                 ustream_printf(cl->us, "Location: https://%s:%d%s\r\n\r\n", host, port, url);
 271         else
 272                 ustream_printf(cl->us, "Location: https://%s%s\r\n\r\n", host, url);
 273
 274         uh_request_done(cl);
 275
 276         return false;
 277 }
 278
 279 static void client_header_complete(struct client *cl)
 280 {
 281         struct http_request *r = &cl->request;
 282
 283         if (!rfc1918_filter_check(cl))
 284                 return;
 285
 286         if (!tls_redirect_check(cl))
 287                 return;
 288
 289         if (r->expect_cont)
 290                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 291
 292         switch(r->ua) {
 293         case UH_UA_MSIE_OLD:
 294                 if (r->method != UH_HTTP_MSG_POST)
 295                         break;
 296
 297                 /* fall through */
 298         case UH_UA_SAFARI:
 299                 r->connection_close = true;
 300                 break;
 301         default:
 302                 break;
 303         }
 304
 305         uh_handle_request(cl);
 306 }
 307
 308 static void client_parse_header(struct client *cl, char *data)
 309 {
 310         struct http_request *r = &cl->request;
 311         char *err;
 312         char *name;
 313         char *val;
 314
 315         if (!*data) {
 316                 uloop_timeout_cancel(&cl->timeout);
 317                 cl->state = CLIENT_STATE_DATA;
 318                 client_header_complete(cl);
 319                 return;
 320         }
 321
 322         val = uh_split_header(data);
 323         if (!val) {
 324                 cl->state = CLIENT_STATE_DONE;
 325                 return;
 326         }
 327
 328         for (name = data; *name; name++)
 329                 if (isupper(*name))
 330                         *name = tolower(*name);
 331
 332         if (!strcmp(data, "expect")) {
 333                 if (!strcasecmp(val, "100-continue"))
 334                         r->expect_cont = true;
 335                 else {
 336                         uh_header_error(cl, 412, "Precondition Failed");
 337                         return;
 338                 }
 339         } else if (!strcmp(data, "content-length")) {
 340                 r->content_length = strtoul(val, &err, 0);
 341                 if (err && *err) {
 342                         uh_header_error(cl, 400, "Bad Request");
 343                         return;
 344                 }
 345         } else if (!strcmp(data, "transfer-encoding")) {
 346                 if (!strcmp(val, "chunked"))
 347                         r->transfer_chunked = true;
 348         } else if (!strcmp(data, "connection")) {
 349                 if (!strcasecmp(val, "close"))
 350                         r->connection_close = true;
 351         } else if (!strcmp(data, "user-agent")) {
 352                 char *str;
 353
 354                 if (strstr(val, "Opera"))
 355                         r->ua = UH_UA_OPERA;
 356                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 357                         r->ua = UH_UA_MSIE_NEW;
 358                         if (str[5] && str[6] == '.') {
 359                                 switch (str[5]) {
 360                                 case '6':
 361                                         if (strstr(str, "SV1"))
 362                                                 break;
 363                                         /* fall through */
 364                                 case '5':
 365                                 case '4':
 366                                         r->ua = UH_UA_MSIE_OLD;
 367                                         break;
 368                                 }
 369                         }
 370                 }
 371                 else if (strstr(val, "Chrome/"))
 372                         r->ua = UH_UA_CHROME;
 373                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 374                         r->ua = UH_UA_SAFARI;
 375                 else if (strstr(val, "Gecko/"))
 376                         r->ua = UH_UA_GECKO;
 377                 else if (strstr(val, "Konqueror"))
 378                         r->ua = UH_UA_KONQUEROR;
 379         }
 380
 381
 382         blobmsg_add_string(&cl->hdr, data, val);
 383
 384         cl->state = CLIENT_STATE_HEADER;
 385 }
 386
 387 void client_poll_post_data(struct client *cl)
 388 {
 389         struct dispatch *d = &cl->dispatch;
 390         struct http_request *r = &cl->request;
 391         char *buf;
 392         int len;
 393
 394         if (cl->state == CLIENT_STATE_DONE)
 395                 return;
 396
 397         while (1) {
 398                 char *sep;
 399                 int offset = 0;
 400                 int cur_len;
 401
 402                 buf = ustream_get_read_buf(cl->us, &len);
 403                 if (!buf || !len)
 404                         break;
 405
 406                 if (!d->data_send)
 407                         return;
 408
 409                 cur_len = min(r->content_length, len);
 410                 if (cur_len) {
 411                         if (d->data_blocked)
 412                                 break;
 413
 414                         if (d->data_send)
 415                                 cur_len = d->data_send(cl, buf, cur_len);
 416
 417                         r->content_length -= cur_len;
 418                         ustream_consume(cl->us, cur_len);
 419                         continue;
 420                 }
 421
 422                 if (!r->transfer_chunked)
 423                         break;
 424
 425                 if (r->transfer_chunked > 1)
 426                         offset = 2;
 427
 428                 sep = strstr(buf + offset, "\r\n");
 429                 if (!sep)
 430                         break;
 431
 432                 *sep = 0;
 433
 434                 r->content_length = strtoul(buf + offset, &sep, 16);
 435                 r->transfer_chunked++;
 436                 ustream_consume(cl->us, sep + 2 - buf);
 437
 438                 /* invalid chunk length */
 439                 if (sep && *sep) {
 440                         r->content_length = 0;
 441                         r->transfer_chunked = 0;
 442                         break;
 443                 }
 444
 445                 /* empty chunk == eof */
 446                 if (!r->content_length) {
 447                         r->transfer_chunked = false;
 448                         break;
 449                 }
 450         }
 451
 452         buf = ustream_get_read_buf(cl->us, &len);
 453         if (!r->content_length && !r->transfer_chunked &&
 454                 cl->state != CLIENT_STATE_DONE) {
 455                 if (cl->dispatch.data_done)
 456                         cl->dispatch.data_done(cl);
 457
 458                 cl->state = CLIENT_STATE_DONE;
 459         }
 460 }
 461
 462 static bool client_data_cb(struct client *cl, char *buf, int len)
 463 {
 464         client_poll_post_data(cl);
 465         return false;
 466 }
 467
 468 static bool client_header_cb(struct client *cl, char *buf, int len)
 469 {
 470         char *newline;
 471         int line_len;
 472
 473         newline = strstr(buf, "\r\n");
 474         if (!newline)
 475                 return false;
 476
 477         *newline = 0;
 478         client_parse_header(cl, buf);
 479         line_len = newline + 2 - buf;
 480         ustream_consume(cl->us, line_len);
 481         if (cl->state == CLIENT_STATE_DATA)
 482                 return client_data_cb(cl, newline + 2, len - line_len);
 483
 484         return true;
 485 }
 486
 487 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 488 static read_cb_t read_cbs[] = {
 489         [CLIENT_STATE_INIT] = client_init_cb,
 490         [CLIENT_STATE_HEADER] = client_header_cb,
 491         [CLIENT_STATE_DATA] = client_data_cb,
 492 };
 493
 494 void uh_client_read_cb(struct client *cl)
 495 {
 496         struct ustream *us = cl->us;
 497         char *str;
 498         int len;
 499
 500         client_done = false;
 501         do {
 502                 str = ustream_get_read_buf(us, &len);
 503                 if (!str || !len)
 504                         break;
 505
 506                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 507                         break;
 508
 509                 if (!read_cbs[cl->state](cl, str, len)) {
 510                         if (len == us->r.buffer_len &&
 511                             cl->state != CLIENT_STATE_DATA)
 512                                 uh_header_error(cl, 413, "Request Entity Too Large");
 513                         break;
 514                 }
 515         } while (!client_done);
 516 }
 517
 518 static void client_close(struct client *cl)
 519 {
 520         if (cl->refcount) {
 521                 cl->state = CLIENT_STATE_CLEANUP;
 522                 return;
 523         }
 524
 525         client_done = true;
 526         n_clients--;
 527         uh_dispatch_done(cl);
 528         uloop_timeout_cancel(&cl->timeout);
 529         if (cl->tls)
 530                 uh_tls_client_detach(cl);
 531         ustream_free(&cl->sfd.stream);
 532         close(cl->sfd.fd.fd);
 533         list_del(&cl->list);
 534         blob_buf_free(&cl->hdr);
 535         free(cl);
 536
 537         uh_unblock_listeners();
 538 }
 539
 540 void uh_client_notify_state(struct client *cl)
 541 {
 542         struct ustream *s = cl->us;
 543
 544         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
 545                 if (cl->state == CLIENT_STATE_DATA)
 546                         return;
 547
 548                 if (!s->eof || s->w.data_bytes)
 549                         return;
 550         }
 551
 552         return client_close(cl);
 553 }
 554
 555 static void client_ustream_read_cb(struct ustream *s, int bytes)
 556 {
 557         struct client *cl = container_of(s, struct client, sfd.stream);
 558
 559         uh_client_read_cb(cl);
 560 }
 561
 562 static void client_ustream_write_cb(struct ustream *s, int bytes)
 563 {
 564         struct client *cl = container_of(s, struct client, sfd.stream);
 565
 566         if (cl->dispatch.write_cb)
 567                 cl->dispatch.write_cb(cl);
 568 }
 569
 570 static void client_notify_state(struct ustream *s)
 571 {
 572         struct client *cl = container_of(s, struct client, sfd.stream);
 573
 574         uh_client_notify_state(cl);
 575 }
 576
 577 static void set_addr(struct uh_addr *addr, void *src)
 578 {
 579         struct sockaddr_in *sin = src;
 580         struct sockaddr_in6 *sin6 = src;
 581
 582         addr->family = sin->sin_family;
 583         if (addr->family == AF_INET) {
 584                 addr->port = ntohs(sin->sin_port);
 585                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 586         } else {
 587                 addr->port = ntohs(sin6->sin6_port);
 588                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 589         }
 590 }
 591
 592 bool uh_accept_client(int fd, bool tls)
 593 {
 594         static struct client *next_client;
 595         struct client *cl;
 596         unsigned int sl;
 597         int sfd;
 598         static int client_id = 0;
 599         struct sockaddr_in6 addr;
 600
 601         if (!next_client)
 602                 next_client = calloc(1, sizeof(*next_client));
 603
 604         cl = next_client;
 605
 606         sl = sizeof(addr);
 607         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 608         if (sfd < 0)
 609                 return false;
 610
 611         set_addr(&cl->peer_addr, &addr);
 612         sl = sizeof(addr);
 613         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 614         set_addr(&cl->srv_addr, &addr);
 615
 616         cl->us = &cl->sfd.stream;
 617         if (tls) {
 618                 uh_tls_client_attach(cl);
 619         } else {
 620                 cl->us->notify_read = client_ustream_read_cb;
 621                 cl->us->notify_write = client_ustream_write_cb;
 622                 cl->us->notify_state = client_notify_state;
 623         }
 624
 625         cl->us->string_data = true;
 626         ustream_fd_init(&cl->sfd, sfd);
 627
 628         uh_poll_connection(cl);
 629         list_add_tail(&cl->list, &clients);
 630
 631         next_client = NULL;
 632         n_clients++;
 633         cl->id = client_id++;
 634         cl->tls = tls;
 635
 636         return true;
 637 }
 638
 639 void uh_close_fds(void)
 640 {
 641         struct client *cl;
 642
 643         uloop_done();
 644         uh_close_listen_fds();
 645         list_for_each_entry(cl, &clients, list) {
 646                 close(cl->sfd.fd.fd);
 647                 if (cl->dispatch.close_fds)
 648                         cl->dispatch.close_fds(cl);
 649         }
 650 }