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 (!uh_use_chunked(cl))
  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         return CLIENT_STATE_HEADER;
 192 }
 193
 194 static bool client_init_cb(struct client *cl, char *buf, int len)
 195 {
 196         char *newline;
 197
 198         newline = strstr(buf, "\r\n");
 199         if (!newline)
 200                 return false;
 201
 202         if (newline == buf) {
 203                 ustream_consume(cl->us, 2);
 204                 return true;
 205         }
 206
 207         *newline = 0;
 208         blob_buf_init(&cl->hdr, 0);
 209         cl->state = client_parse_request(cl, buf);
 210         ustream_consume(cl->us, newline + 2 - buf);
 211         if (cl->state == CLIENT_STATE_DONE)
 212                 uh_header_error(cl, 400, "Bad Request");
 213
 214         return true;
 215 }
 216
 217 static bool rfc1918_filter_check(struct client *cl)
 218 {
 219         if (!conf.rfc1918_filter)
 220                 return true;
 221
 222         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 223                 return true;
 224
 225         uh_client_error(cl, 403, "Forbidden",
 226                         "Rejected request from RFC1918 IP "
 227                         "to public server address");
 228         return false;
 229 }
 230
 231 static bool tls_redirect_check(struct client *cl)
 232 {
 233         int rem, port;
 234         struct blob_attr *cur;
 235         char *ptr, *url = NULL, *host = NULL;
 236
 237         if (cl->tls || !conf.tls_redirect)
 238                 return true;
 239
 240         if ((port = uh_first_tls_port(cl->srv_addr.family)) == -1)
 241                 return true;
 242
 243         blob_for_each_attr(cur, cl->hdr.head, rem) {
 244                 if (!strcmp(blobmsg_name(cur), "host"))
 245                         host = blobmsg_get_string(cur);
 246
 247                 if (!strcmp(blobmsg_name(cur), "URL"))
 248                         url = blobmsg_get_string(cur);
 249
 250                 if (url && host)
 251                         break;
 252         }
 253
 254         if (!url || !host)
 255                 return true;
 256
 257         if ((ptr = strchr(host, ']')) != NULL)
 258                 *(ptr+1) = 0;
 259         else if ((ptr = strchr(host, ':')) != NULL)
 260                 *ptr = 0;
 261
 262         cl->request.disable_chunked = true;
 263         cl->request.connection_close = true;
 264
 265         uh_http_header(cl, 307, "Temporary Redirect");
 266
 267         if (port != 443)
 268                 ustream_printf(cl->us, "Location: https://%s:%d%s\r\n\r\n", host, port, url);
 269         else
 270                 ustream_printf(cl->us, "Location: https://%s%s\r\n\r\n", host, url);
 271
 272         uh_request_done(cl);
 273
 274         return false;
 275 }
 276
 277 static void client_header_complete(struct client *cl)
 278 {
 279         struct http_request *r = &cl->request;
 280
 281         if (!rfc1918_filter_check(cl))
 282                 return;
 283
 284         if (!tls_redirect_check(cl))
 285                 return;
 286
 287         if (r->expect_cont)
 288                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 289
 290         switch(r->ua) {
 291         case UH_UA_MSIE_OLD:
 292                 if (r->method != UH_HTTP_MSG_POST)
 293                         break;
 294
 295                 /* fall through */
 296         case UH_UA_SAFARI:
 297                 r->connection_close = true;
 298                 break;
 299         default:
 300                 break;
 301         }
 302
 303         uh_handle_request(cl);
 304 }
 305
 306 static void client_parse_header(struct client *cl, char *data)
 307 {
 308         struct http_request *r = &cl->request;
 309         char *err;
 310         char *name;
 311         char *val;
 312
 313         if (!*data) {
 314                 uloop_timeout_cancel(&cl->timeout);
 315                 cl->state = CLIENT_STATE_DATA;
 316                 client_header_complete(cl);
 317                 return;
 318         }
 319
 320         val = uh_split_header(data);
 321         if (!val) {
 322                 cl->state = CLIENT_STATE_DONE;
 323                 return;
 324         }
 325
 326         for (name = data; *name; name++)
 327                 if (isupper(*name))
 328                         *name = tolower(*name);
 329
 330         if (!strcmp(data, "expect")) {
 331                 if (!strcasecmp(val, "100-continue"))
 332                         r->expect_cont = true;
 333                 else {
 334                         uh_header_error(cl, 412, "Precondition Failed");
 335                         return;
 336                 }
 337         } else if (!strcmp(data, "content-length")) {
 338                 r->content_length = strtoul(val, &err, 0);
 339                 if (err && *err) {
 340                         uh_header_error(cl, 400, "Bad Request");
 341                         return;
 342                 }
 343         } else if (!strcmp(data, "transfer-encoding")) {
 344                 if (!strcmp(val, "chunked"))
 345                         r->transfer_chunked = true;
 346         } else if (!strcmp(data, "connection")) {
 347                 if (!strcasecmp(val, "close"))
 348                         r->connection_close = true;
 349         } else if (!strcmp(data, "user-agent")) {
 350                 char *str;
 351
 352                 if (strstr(val, "Opera"))
 353                         r->ua = UH_UA_OPERA;
 354                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 355                         r->ua = UH_UA_MSIE_NEW;
 356                         if (str[5] && str[6] == '.') {
 357                                 switch (str[5]) {
 358                                 case '6':
 359                                         if (strstr(str, "SV1"))
 360                                                 break;
 361                                         /* fall through */
 362                                 case '5':
 363                                 case '4':
 364                                         r->ua = UH_UA_MSIE_OLD;
 365                                         break;
 366                                 }
 367                         }
 368                 }
 369                 else if (strstr(val, "Chrome/"))
 370                         r->ua = UH_UA_CHROME;
 371                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 372                         r->ua = UH_UA_SAFARI;
 373                 else if (strstr(val, "Gecko/"))
 374                         r->ua = UH_UA_GECKO;
 375                 else if (strstr(val, "Konqueror"))
 376                         r->ua = UH_UA_KONQUEROR;
 377         }
 378
 379
 380         blobmsg_add_string(&cl->hdr, data, val);
 381
 382         cl->state = CLIENT_STATE_HEADER;
 383 }
 384
 385 void client_poll_post_data(struct client *cl)
 386 {
 387         struct dispatch *d = &cl->dispatch;
 388         struct http_request *r = &cl->request;
 389         char *buf;
 390         int len;
 391
 392         if (cl->state == CLIENT_STATE_DONE)
 393                 return;
 394
 395         while (1) {
 396                 char *sep;
 397                 int offset = 0;
 398                 int cur_len;
 399
 400                 buf = ustream_get_read_buf(cl->us, &len);
 401                 if (!buf || !len)
 402                         break;
 403
 404                 if (!d->data_send)
 405                         return;
 406
 407                 cur_len = min(r->content_length, len);
 408                 if (cur_len) {
 409                         if (d->data_blocked)
 410                                 break;
 411
 412                         if (d->data_send)
 413                                 cur_len = d->data_send(cl, buf, cur_len);
 414
 415                         r->content_length -= cur_len;
 416                         ustream_consume(cl->us, cur_len);
 417                         continue;
 418                 }
 419
 420                 if (!r->transfer_chunked)
 421                         break;
 422
 423                 if (r->transfer_chunked > 1)
 424                         offset = 2;
 425
 426                 sep = strstr(buf + offset, "\r\n");
 427                 if (!sep)
 428                         break;
 429
 430                 *sep = 0;
 431
 432                 r->content_length = strtoul(buf + offset, &sep, 16);
 433                 r->transfer_chunked++;
 434                 ustream_consume(cl->us, sep + 2 - buf);
 435
 436                 /* invalid chunk length */
 437                 if (sep && *sep) {
 438                         r->content_length = 0;
 439                         r->transfer_chunked = 0;
 440                         break;
 441                 }
 442
 443                 /* empty chunk == eof */
 444                 if (!r->content_length) {
 445                         r->transfer_chunked = false;
 446                         break;
 447                 }
 448         }
 449
 450         buf = ustream_get_read_buf(cl->us, &len);
 451         if (!r->content_length && !r->transfer_chunked &&
 452                 cl->state != CLIENT_STATE_DONE) {
 453                 if (cl->dispatch.data_done)
 454                         cl->dispatch.data_done(cl);
 455
 456                 cl->state = CLIENT_STATE_DONE;
 457         }
 458 }
 459
 460 static bool client_data_cb(struct client *cl, char *buf, int len)
 461 {
 462         client_poll_post_data(cl);
 463         return false;
 464 }
 465
 466 static bool client_header_cb(struct client *cl, char *buf, int len)
 467 {
 468         char *newline;
 469         int line_len;
 470
 471         newline = strstr(buf, "\r\n");
 472         if (!newline)
 473                 return false;
 474
 475         *newline = 0;
 476         client_parse_header(cl, buf);
 477         line_len = newline + 2 - buf;
 478         ustream_consume(cl->us, line_len);
 479         if (cl->state == CLIENT_STATE_DATA)
 480                 return client_data_cb(cl, newline + 2, len - line_len);
 481
 482         return true;
 483 }
 484
 485 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 486 static read_cb_t read_cbs[] = {
 487         [CLIENT_STATE_INIT] = client_init_cb,
 488         [CLIENT_STATE_HEADER] = client_header_cb,
 489         [CLIENT_STATE_DATA] = client_data_cb,
 490 };
 491
 492 void uh_client_read_cb(struct client *cl)
 493 {
 494         struct ustream *us = cl->us;
 495         char *str;
 496         int len;
 497
 498         client_done = false;
 499         do {
 500                 str = ustream_get_read_buf(us, &len);
 501                 if (!str || !len)
 502                         break;
 503
 504                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 505                         break;
 506
 507                 if (!read_cbs[cl->state](cl, str, len)) {
 508                         if (len == us->r.buffer_len &&
 509                             cl->state != CLIENT_STATE_DATA)
 510                                 uh_header_error(cl, 413, "Request Entity Too Large");
 511                         break;
 512                 }
 513         } while (!client_done);
 514 }
 515
 516 static void client_close(struct client *cl)
 517 {
 518         if (cl->refcount) {
 519                 cl->state = CLIENT_STATE_CLEANUP;
 520                 return;
 521         }
 522
 523         client_done = true;
 524         n_clients--;
 525         uh_dispatch_done(cl);
 526         uloop_timeout_cancel(&cl->timeout);
 527         if (cl->tls)
 528                 uh_tls_client_detach(cl);
 529         ustream_free(&cl->sfd.stream);
 530         close(cl->sfd.fd.fd);
 531         list_del(&cl->list);
 532         blob_buf_free(&cl->hdr);
 533         free(cl);
 534
 535         uh_unblock_listeners();
 536 }
 537
 538 void uh_client_notify_state(struct client *cl)
 539 {
 540         struct ustream *s = cl->us;
 541
 542         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
 543                 if (cl->state == CLIENT_STATE_DATA)
 544                         return;
 545
 546                 if (!s->eof || s->w.data_bytes)
 547                         return;
 548         }
 549
 550         return client_close(cl);
 551 }
 552
 553 static void client_ustream_read_cb(struct ustream *s, int bytes)
 554 {
 555         struct client *cl = container_of(s, struct client, sfd.stream);
 556
 557         uh_client_read_cb(cl);
 558 }
 559
 560 static void client_ustream_write_cb(struct ustream *s, int bytes)
 561 {
 562         struct client *cl = container_of(s, struct client, sfd.stream);
 563
 564         if (cl->dispatch.write_cb)
 565                 cl->dispatch.write_cb(cl);
 566 }
 567
 568 static void client_notify_state(struct ustream *s)
 569 {
 570         struct client *cl = container_of(s, struct client, sfd.stream);
 571
 572         uh_client_notify_state(cl);
 573 }
 574
 575 static void set_addr(struct uh_addr *addr, void *src)
 576 {
 577         struct sockaddr_in *sin = src;
 578         struct sockaddr_in6 *sin6 = src;
 579
 580         addr->family = sin->sin_family;
 581         if (addr->family == AF_INET) {
 582                 addr->port = ntohs(sin->sin_port);
 583                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 584         } else {
 585                 addr->port = ntohs(sin6->sin6_port);
 586                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 587         }
 588 }
 589
 590 bool uh_accept_client(int fd, bool tls)
 591 {
 592         static struct client *next_client;
 593         struct client *cl;
 594         unsigned int sl;
 595         int sfd;
 596         static int client_id = 0;
 597         struct sockaddr_in6 addr;
 598
 599         if (!next_client)
 600                 next_client = calloc(1, sizeof(*next_client));
 601
 602         cl = next_client;
 603
 604         sl = sizeof(addr);
 605         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 606         if (sfd < 0)
 607                 return false;
 608
 609         set_addr(&cl->peer_addr, &addr);
 610         sl = sizeof(addr);
 611         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 612         set_addr(&cl->srv_addr, &addr);
 613
 614         cl->us = &cl->sfd.stream;
 615         if (tls) {
 616                 uh_tls_client_attach(cl);
 617         } else {
 618                 cl->us->notify_read = client_ustream_read_cb;
 619                 cl->us->notify_write = client_ustream_write_cb;
 620                 cl->us->notify_state = client_notify_state;
 621         }
 622
 623         cl->us->string_data = true;
 624         ustream_fd_init(&cl->sfd, sfd);
 625
 626         uh_poll_connection(cl);
 627         list_add_tail(&cl->list, &clients);
 628
 629         next_client = NULL;
 630         n_clients++;
 631         cl->id = client_id++;
 632         cl->tls = tls;
 633
 634         return true;
 635 }
 636
 637 void uh_close_fds(void)
 638 {
 639         struct client *cl;
 640
 641         uloop_done();
 642         uh_close_listen_fds();
 643         list_for_each_entry(cl, &clients, list) {
 644                 close(cl->sfd.fd.fd);
 645                 if (cl->dispatch.close_fds)
 646                         cl->dispatch.close_fds(cl);
 647         }
 648 }