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         [UH_HTTP_MSG_PUT] = "PUT",
  44         [UH_HTTP_MSG_PATCH] = "PATCH",
  45         [UH_HTTP_MSG_DELETE] = "DELETE",
  46 };
  47
  48 void uh_http_header(struct client *cl, int code, const char *summary)
  49 {
  50         struct http_request *r = &cl->request;
  51         struct blob_attr *cur;
  52         const char *enc = "Transfer-Encoding: chunked\r\n";
  53         const char *conn;
  54         int rem;
  55
  56         cl->http_code = code;
  57
  58         if (!uh_use_chunked(cl))
  59                 enc = "";
  60
  61         if (r->connection_close)
  62                 conn = "Connection: close";
  63         else
  64                 conn = "Connection: Keep-Alive";
  65
  66         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  67                 http_versions[cl->request.version],
  68                 code, summary, conn, enc);
  69
  70         if (!r->connection_close)
  71                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
  72
  73         blobmsg_for_each_attr(cur, cl->hdr_response.head, rem)
  74                 ustream_printf(cl->us, "%s: %s\r\n", blobmsg_name(cur),
  75                                blobmsg_get_string(cur));
  76 }
  77
  78 static void uh_connection_close(struct client *cl)
  79 {
  80         cl->state = CLIENT_STATE_CLOSE;
  81         cl->us->eof = true;
  82         ustream_state_change(cl->us);
  83 }
  84
  85 static void uh_dispatch_done(struct client *cl)
  86 {
  87         if (cl->dispatch.free)
  88                 cl->dispatch.free(cl);
  89         if (cl->dispatch.req_free)
  90                 cl->dispatch.req_free(cl);
  91 }
  92
  93 static void client_timeout(struct uloop_timeout *timeout)
  94 {
  95         struct client *cl = container_of(timeout, struct client, timeout);
  96
  97         cl->state = CLIENT_STATE_CLOSE;
  98         uh_connection_close(cl);
  99 }
 100
 101 static void uh_set_client_timeout(struct client *cl, int timeout)
 102 {
 103         cl->timeout.cb = client_timeout;
 104         uloop_timeout_set(&cl->timeout, timeout * 1000);
 105 }
 106
 107 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
 108 {
 109         struct client *cl = container_of(timeout, struct client, timeout);
 110         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
 111
 112         uh_set_client_timeout(cl, sec);
 113         cl->us->notify_read(cl->us, 0);
 114 }
 115
 116 static void uh_poll_connection(struct client *cl)
 117 {
 118         cl->timeout.cb = uh_keepalive_poll_cb;
 119         uloop_timeout_set(&cl->timeout, 1);
 120 }
 121
 122 void uh_request_done(struct client *cl)
 123 {
 124         uh_chunk_eof(cl);
 125         uh_dispatch_done(cl);
 126         blob_buf_init(&cl->hdr_response, 0);
 127         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 128
 129         if (!conf.http_keepalive || cl->request.connection_close)
 130                 return uh_connection_close(cl);
 131
 132         cl->state = CLIENT_STATE_INIT;
 133         cl->requests++;
 134         uh_poll_connection(cl);
 135 }
 136
 137 void __printf(4, 5)
 138 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 139 {
 140         va_list arg;
 141
 142         uh_http_header(cl, code, summary);
 143         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 144
 145         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 146
 147         if (fmt) {
 148                 va_start(arg, fmt);
 149                 uh_chunk_vprintf(cl, fmt, arg);
 150                 va_end(arg);
 151         }
 152
 153         uh_request_done(cl);
 154 }
 155
 156 static void uh_header_error(struct client *cl, int code, const char *summary)
 157 {
 158         uh_client_error(cl, code, summary, NULL);
 159         uh_connection_close(cl);
 160 }
 161
 162 static int find_idx(const char * const *list, int max, const char *str)
 163 {
 164         int i;
 165
 166         for (i = 0; i < max; i++)
 167                 if (!strcmp(list[i], str))
 168                         return i;
 169
 170         return -1;
 171 }
 172
 173 static int client_parse_request(struct client *cl, char *data)
 174 {
 175         struct http_request *req = &cl->request;
 176         char *type, *path, *version;
 177         int h_method, h_version;
 178
 179         type = strtok(data, " ");
 180         path = strtok(NULL, " ");
 181         version = strtok(NULL, " ");
 182         if (!type || !path || !version)
 183                 return CLIENT_STATE_DONE;
 184
 185         blobmsg_add_string(&cl->hdr, "URL", path);
 186
 187         memset(&cl->request, 0, sizeof(cl->request));
 188         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 189         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 190         if (h_method < 0 || h_version < 0) {
 191                 req->version = UH_HTTP_VER_1_0;
 192                 return CLIENT_STATE_DONE;
 193         }
 194
 195         req->method = h_method;
 196         req->version = h_version;
 197         if (req->version < UH_HTTP_VER_1_1 || req->method == UH_HTTP_MSG_POST ||
 198             !conf.http_keepalive)
 199                 req->connection_close = true;
 200
 201         return CLIENT_STATE_HEADER;
 202 }
 203
 204 static bool client_init_cb(struct client *cl, char *buf, int len)
 205 {
 206         char *newline;
 207
 208         newline = strstr(buf, "\r\n");
 209         if (!newline)
 210                 return false;
 211
 212         if (newline == buf) {
 213                 ustream_consume(cl->us, 2);
 214                 return true;
 215         }
 216
 217         *newline = 0;
 218         blob_buf_init(&cl->hdr, 0);
 219         cl->state = client_parse_request(cl, buf);
 220         ustream_consume(cl->us, newline + 2 - buf);
 221         if (cl->state == CLIENT_STATE_DONE)
 222                 uh_header_error(cl, 400, "Bad Request");
 223
 224         return true;
 225 }
 226
 227 static bool rfc1918_filter_check(struct client *cl)
 228 {
 229         if (!conf.rfc1918_filter)
 230                 return true;
 231
 232         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 233                 return true;
 234
 235         uh_client_error(cl, 403, "Forbidden",
 236                         "Rejected request from RFC1918 IP "
 237                         "to public server address");
 238         return false;
 239 }
 240
 241 static bool tls_redirect_check(struct client *cl)
 242 {
 243         int rem, port;
 244         struct blob_attr *cur;
 245         char *ptr, *url = NULL, *host = NULL;
 246
 247         if (cl->tls || !conf.tls_redirect)
 248                 return true;
 249
 250         if ((port = uh_first_tls_port(cl->srv_addr.family)) == -1)
 251                 return true;
 252
 253         blob_for_each_attr(cur, cl->hdr.head, rem) {
 254                 if (!strcmp(blobmsg_name(cur), "host"))
 255                         host = blobmsg_get_string(cur);
 256
 257                 if (!strcmp(blobmsg_name(cur), "URL"))
 258                         url = blobmsg_get_string(cur);
 259
 260                 if (url && host)
 261                         break;
 262         }
 263
 264         if (!url || !host)
 265                 return true;
 266
 267         if ((ptr = strchr(host, ']')) != NULL)
 268                 *(ptr+1) = 0;
 269         else if ((ptr = strchr(host, ':')) != NULL)
 270                 *ptr = 0;
 271
 272         cl->request.disable_chunked = true;
 273         cl->request.connection_close = true;
 274
 275         uh_http_header(cl, 307, "Temporary Redirect");
 276
 277         if (port != 443)
 278                 ustream_printf(cl->us, "Location: https://%s:%d%s\r\n\r\n", host, port, url);
 279         else
 280                 ustream_printf(cl->us, "Location: https://%s%s\r\n\r\n", host, url);
 281
 282         uh_request_done(cl);
 283
 284         return false;
 285 }
 286
 287 static void client_header_complete(struct client *cl)
 288 {
 289         struct http_request *r = &cl->request;
 290
 291         if (!rfc1918_filter_check(cl))
 292                 return;
 293
 294         if (!tls_redirect_check(cl))
 295                 return;
 296
 297         if (r->expect_cont)
 298                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 299
 300         switch(r->ua) {
 301         case UH_UA_MSIE_OLD:
 302                 if (r->method != UH_HTTP_MSG_POST)
 303                         break;
 304
 305                 /* fall through */
 306         case UH_UA_SAFARI:
 307                 r->connection_close = true;
 308                 break;
 309         default:
 310                 break;
 311         }
 312
 313         uh_handle_request(cl);
 314 }
 315
 316 static void client_parse_header(struct client *cl, char *data)
 317 {
 318         struct http_request *r = &cl->request;
 319         char *err;
 320         char *name;
 321         char *val;
 322
 323         if (!*data) {
 324                 uloop_timeout_cancel(&cl->timeout);
 325                 cl->state = CLIENT_STATE_DATA;
 326                 client_header_complete(cl);
 327                 return;
 328         }
 329
 330         val = uh_split_header(data);
 331         if (!val) {
 332                 cl->state = CLIENT_STATE_DONE;
 333                 return;
 334         }
 335
 336         for (name = data; *name; name++)
 337                 if (isupper(*name))
 338                         *name = tolower(*name);
 339
 340         if (!strcmp(data, "expect")) {
 341                 if (!strcasecmp(val, "100-continue"))
 342                         r->expect_cont = true;
 343                 else {
 344                         uh_header_error(cl, 412, "Precondition Failed");
 345                         return;
 346                 }
 347         } else if (!strcmp(data, "content-length")) {
 348                 r->content_length = strtoul(val, &err, 0);
 349                 if ((err && *err) || r->content_length < 0) {
 350                         uh_header_error(cl, 400, "Bad Request");
 351                         return;
 352                 }
 353         } else if (!strcmp(data, "transfer-encoding")) {
 354                 if (!strcmp(val, "chunked"))
 355                         r->transfer_chunked = true;
 356         } else if (!strcmp(data, "connection")) {
 357                 if (!strcasecmp(val, "close"))
 358                         r->connection_close = true;
 359         } else if (!strcmp(data, "user-agent")) {
 360                 char *str;
 361
 362                 if (strstr(val, "Opera"))
 363                         r->ua = UH_UA_OPERA;
 364                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 365                         r->ua = UH_UA_MSIE_NEW;
 366                         if (str[5] && str[6] == '.') {
 367                                 switch (str[5]) {
 368                                 case '6':
 369                                         if (strstr(str, "SV1"))
 370                                                 break;
 371                                         /* fall through */
 372                                 case '5':
 373                                 case '4':
 374                                         r->ua = UH_UA_MSIE_OLD;
 375                                         break;
 376                                 }
 377                         }
 378                 }
 379                 else if (strstr(val, "Chrome/"))
 380                         r->ua = UH_UA_CHROME;
 381                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 382                         r->ua = UH_UA_SAFARI;
 383                 else if (strstr(val, "Gecko/"))
 384                         r->ua = UH_UA_GECKO;
 385                 else if (strstr(val, "Konqueror"))
 386                         r->ua = UH_UA_KONQUEROR;
 387         }
 388
 389
 390         blobmsg_add_string(&cl->hdr, data, val);
 391
 392         cl->state = CLIENT_STATE_HEADER;
 393 }
 394
 395 void client_poll_post_data(struct client *cl)
 396 {
 397         struct dispatch *d = &cl->dispatch;
 398         struct http_request *r = &cl->request;
 399         char *buf;
 400         int len;
 401
 402         if (cl->state == CLIENT_STATE_DONE)
 403                 return;
 404
 405         while (1) {
 406                 char *sep;
 407                 int offset = 0;
 408                 int cur_len;
 409
 410                 buf = ustream_get_read_buf(cl->us, &len);
 411                 if (!buf || !len)
 412                         break;
 413
 414                 if (!d->data_send)
 415                         return;
 416
 417                 cur_len = min(r->content_length, len);
 418                 if (cur_len) {
 419                         if (d->data_blocked)
 420                                 break;
 421
 422                         if (d->data_send)
 423                                 cur_len = d->data_send(cl, buf, cur_len);
 424
 425                         r->content_length -= cur_len;
 426                         ustream_consume(cl->us, cur_len);
 427                         continue;
 428                 }
 429
 430                 if (!r->transfer_chunked)
 431                         break;
 432
 433                 if (r->transfer_chunked > 1)
 434                         offset = 2;
 435
 436                 sep = strstr(buf + offset, "\r\n");
 437                 if (!sep)
 438                         break;
 439
 440                 *sep = 0;
 441
 442                 r->content_length = strtoul(buf + offset, &sep, 16);
 443                 r->transfer_chunked++;
 444                 ustream_consume(cl->us, sep + 2 - buf);
 445
 446                 /* invalid chunk length */
 447                 if ((sep && *sep) || r->content_length < 0) {
 448                         r->content_length = 0;
 449                         r->transfer_chunked = 0;
 450                         break;
 451                 }
 452
 453                 /* empty chunk == eof */
 454                 if (!r->content_length) {
 455                         r->transfer_chunked = false;
 456                         break;
 457                 }
 458         }
 459
 460         buf = ustream_get_read_buf(cl->us, &len);
 461         if (!r->content_length && !r->transfer_chunked &&
 462                 cl->state != CLIENT_STATE_DONE) {
 463                 if (cl->dispatch.data_done)
 464                         cl->dispatch.data_done(cl);
 465
 466                 cl->state = CLIENT_STATE_DONE;
 467         }
 468 }
 469
 470 static bool client_data_cb(struct client *cl, char *buf, int len)
 471 {
 472         client_poll_post_data(cl);
 473         return false;
 474 }
 475
 476 static bool client_header_cb(struct client *cl, char *buf, int len)
 477 {
 478         char *newline;
 479         int line_len;
 480
 481         newline = strstr(buf, "\r\n");
 482         if (!newline)
 483                 return false;
 484
 485         *newline = 0;
 486         client_parse_header(cl, buf);
 487         line_len = newline + 2 - buf;
 488         ustream_consume(cl->us, line_len);
 489         if (cl->state == CLIENT_STATE_DATA)
 490                 return client_data_cb(cl, newline + 2, len - line_len);
 491
 492         return true;
 493 }
 494
 495 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 496 static read_cb_t read_cbs[] = {
 497         [CLIENT_STATE_INIT] = client_init_cb,
 498         [CLIENT_STATE_HEADER] = client_header_cb,
 499         [CLIENT_STATE_DATA] = client_data_cb,
 500 };
 501
 502 void uh_client_read_cb(struct client *cl)
 503 {
 504         struct ustream *us = cl->us;
 505         char *str;
 506         int len;
 507
 508         client_done = false;
 509         do {
 510                 str = ustream_get_read_buf(us, &len);
 511                 if (!str || !len)
 512                         break;
 513
 514                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 515                         break;
 516
 517                 if (!read_cbs[cl->state](cl, str, len)) {
 518                         if (len == us->r.buffer_len &&
 519                             cl->state != CLIENT_STATE_DATA)
 520                                 uh_header_error(cl, 413, "Request Entity Too Large");
 521                         break;
 522                 }
 523         } while (!client_done);
 524 }
 525
 526 static void client_close(struct client *cl)
 527 {
 528         if (cl->refcount) {
 529                 cl->state = CLIENT_STATE_CLEANUP;
 530                 return;
 531         }
 532
 533         client_done = true;
 534         n_clients--;
 535         uh_dispatch_done(cl);
 536         uloop_timeout_cancel(&cl->timeout);
 537         if (cl->tls)
 538                 uh_tls_client_detach(cl);
 539         ustream_free(&cl->sfd.stream);
 540         close(cl->sfd.fd.fd);
 541         list_del(&cl->list);
 542         blob_buf_free(&cl->hdr);
 543         blob_buf_free(&cl->hdr_response);
 544         free(cl);
 545
 546         uh_unblock_listeners();
 547 }
 548
 549 void uh_client_notify_state(struct client *cl)
 550 {
 551         struct ustream *s = cl->us;
 552
 553         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
 554                 if (cl->state == CLIENT_STATE_DATA)
 555                         return;
 556
 557                 if (!s->eof || s->w.data_bytes)
 558                         return;
 559
 560 #ifdef HAVE_TLS
 561                 if (cl->tls && cl->ssl.conn && cl->ssl.conn->w.data_bytes) {
 562                         cl->ssl.conn->eof = s->eof;
 563                         if (!ustream_write_pending(cl->ssl.conn))
 564                                 return;
 565                 }
 566 #endif
 567         }
 568
 569         return client_close(cl);
 570 }
 571
 572 static void client_ustream_read_cb(struct ustream *s, int bytes)
 573 {
 574         struct client *cl = container_of(s, struct client, sfd.stream);
 575
 576         uh_client_read_cb(cl);
 577 }
 578
 579 static void client_ustream_write_cb(struct ustream *s, int bytes)
 580 {
 581         struct client *cl = container_of(s, struct client, sfd.stream);
 582
 583         if (cl->dispatch.write_cb)
 584                 cl->dispatch.write_cb(cl);
 585 }
 586
 587 static void client_notify_state(struct ustream *s)
 588 {
 589         struct client *cl = container_of(s, struct client, sfd.stream);
 590
 591         uh_client_notify_state(cl);
 592 }
 593
 594 static void set_addr(struct uh_addr *addr, void *src)
 595 {
 596         struct sockaddr_in *sin = src;
 597         struct sockaddr_in6 *sin6 = src;
 598
 599         addr->family = sin->sin_family;
 600         if (addr->family == AF_INET) {
 601                 addr->port = ntohs(sin->sin_port);
 602                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 603         } else {
 604                 addr->port = ntohs(sin6->sin6_port);
 605                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 606         }
 607 }
 608
 609 bool uh_accept_client(int fd, bool tls)
 610 {
 611         static struct client *next_client;
 612         struct client *cl;
 613         unsigned int sl;
 614         int sfd;
 615         static int client_id = 0;
 616         struct sockaddr_in6 addr;
 617
 618         if (!next_client)
 619                 next_client = calloc(1, sizeof(*next_client));
 620
 621         cl = next_client;
 622
 623         sl = sizeof(addr);
 624         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 625         if (sfd < 0)
 626                 return false;
 627
 628         set_addr(&cl->peer_addr, &addr);
 629         sl = sizeof(addr);
 630         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 631         set_addr(&cl->srv_addr, &addr);
 632
 633         cl->us = &cl->sfd.stream;
 634         if (tls) {
 635                 uh_tls_client_attach(cl);
 636         } else {
 637                 cl->us->notify_read = client_ustream_read_cb;
 638                 cl->us->notify_write = client_ustream_write_cb;
 639                 cl->us->notify_state = client_notify_state;
 640         }
 641
 642         cl->us->string_data = true;
 643         ustream_fd_init(&cl->sfd, sfd);
 644
 645         uh_poll_connection(cl);
 646         list_add_tail(&cl->list, &clients);
 647
 648         next_client = NULL;
 649         n_clients++;
 650         cl->id = client_id++;
 651         cl->tls = tls;
 652
 653         return true;
 654 }
 655
 656 void uh_close_fds(void)
 657 {
 658         struct client *cl;
 659
 660         uloop_done();
 661         uh_close_listen_fds();
 662         list_for_each_entry(cl, &clients, list) {
 663                 close(cl->sfd.fd.fd);
 664                 if (cl->dispatch.close_fds)
 665                         cl->dispatch.close_fds(cl);
 666         }
 667 }