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 };
  43
  44 void uh_http_header(struct client *cl, int code, const char *summary)
  45 {
  46         struct http_request *r = &cl->request;
  47         const char *enc = "Transfer-Encoding: chunked\r\n";
  48         const char *conn;
  49
  50         if (!uh_use_chunked(cl))
  51                 enc = "";
  52
  53         if (r->connection_close)
  54                 conn = "Connection: close";
  55         else
  56                 conn = "Connection: Keep-Alive";
  57
  58         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  59                 http_versions[cl->request.version],
  60                 code, summary, conn, enc);
  61
  62         if (!r->connection_close)
  63                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
  64 }
  65
  66 static void uh_connection_close(struct client *cl)
  67 {
  68         cl->state = CLIENT_STATE_CLOSE;
  69         cl->us->eof = true;
  70         ustream_state_change(cl->us);
  71 }
  72
  73 static void uh_dispatch_done(struct client *cl)
  74 {
  75         if (cl->dispatch.free)
  76                 cl->dispatch.free(cl);
  77         if (cl->dispatch.req_free)
  78                 cl->dispatch.req_free(cl);
  79 }
  80
  81 static void client_timeout(struct uloop_timeout *timeout)
  82 {
  83         struct client *cl = container_of(timeout, struct client, timeout);
  84
  85         cl->state = CLIENT_STATE_CLOSE;
  86         uh_connection_close(cl);
  87 }
  88
  89 static void uh_set_client_timeout(struct client *cl, int timeout)
  90 {
  91         cl->timeout.cb = client_timeout;
  92         uloop_timeout_set(&cl->timeout, timeout * 1000);
  93 }
  94
  95 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
  96 {
  97         struct client *cl = container_of(timeout, struct client, timeout);
  98         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
  99
 100         uh_set_client_timeout(cl, sec);
 101         cl->us->notify_read(cl->us, 0);
 102 }
 103
 104 static void uh_poll_connection(struct client *cl)
 105 {
 106         cl->timeout.cb = uh_keepalive_poll_cb;
 107         uloop_timeout_set(&cl->timeout, 1);
 108 }
 109
 110 void uh_request_done(struct client *cl)
 111 {
 112         uh_chunk_eof(cl);
 113         uh_dispatch_done(cl);
 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 || req->method == UH_HTTP_MSG_POST ||
 185             !conf.http_keepalive)
 186                 req->connection_close = true;
 187
 188         return CLIENT_STATE_HEADER;
 189 }
 190
 191 static bool client_init_cb(struct client *cl, char *buf, int len)
 192 {
 193         char *newline;
 194
 195         newline = strstr(buf, "\r\n");
 196         if (!newline)
 197                 return false;
 198
 199         if (newline == buf) {
 200                 ustream_consume(cl->us, 2);
 201                 return true;
 202         }
 203
 204         *newline = 0;
 205         blob_buf_init(&cl->hdr, 0);
 206         cl->state = client_parse_request(cl, buf);
 207         ustream_consume(cl->us, newline + 2 - buf);
 208         if (cl->state == CLIENT_STATE_DONE)
 209                 uh_header_error(cl, 400, "Bad Request");
 210
 211         return true;
 212 }
 213
 214 static bool rfc1918_filter_check(struct client *cl)
 215 {
 216         if (!conf.rfc1918_filter)
 217                 return true;
 218
 219         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 220                 return true;
 221
 222         uh_client_error(cl, 403, "Forbidden",
 223                         "Rejected request from RFC1918 IP "
 224                         "to public server address");
 225         return false;
 226 }
 227
 228 static void client_header_complete(struct client *cl)
 229 {
 230         struct http_request *r = &cl->request;
 231
 232         if (!rfc1918_filter_check(cl))
 233                 return;
 234
 235         if (r->expect_cont)
 236                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 237
 238         switch(r->ua) {
 239         case UH_UA_MSIE_OLD:
 240                 if (r->method != UH_HTTP_MSG_POST)
 241                         break;
 242
 243                 /* fall through */
 244         case UH_UA_SAFARI:
 245                 r->connection_close = true;
 246                 break;
 247         default:
 248                 break;
 249         }
 250
 251         uh_handle_request(cl);
 252 }
 253
 254 static void client_parse_header(struct client *cl, char *data)
 255 {
 256         struct http_request *r = &cl->request;
 257         char *err;
 258         char *name;
 259         char *val;
 260
 261         if (!*data) {
 262                 uloop_timeout_cancel(&cl->timeout);
 263                 cl->state = CLIENT_STATE_DATA;
 264                 client_header_complete(cl);
 265                 return;
 266         }
 267
 268         val = uh_split_header(data);
 269         if (!val) {
 270                 cl->state = CLIENT_STATE_DONE;
 271                 return;
 272         }
 273
 274         for (name = data; *name; name++)
 275                 if (isupper(*name))
 276                         *name = tolower(*name);
 277
 278         if (!strcmp(data, "expect")) {
 279                 if (!strcasecmp(val, "100-continue"))
 280                         r->expect_cont = true;
 281                 else {
 282                         uh_header_error(cl, 412, "Precondition Failed");
 283                         return;
 284                 }
 285         } else if (!strcmp(data, "content-length")) {
 286                 r->content_length = strtoul(val, &err, 0);
 287                 if (err && *err) {
 288                         uh_header_error(cl, 400, "Bad Request");
 289                         return;
 290                 }
 291         } else if (!strcmp(data, "transfer-encoding")) {
 292                 if (!strcmp(val, "chunked"))
 293                         r->transfer_chunked = true;
 294         } else if (!strcmp(data, "connection")) {
 295                 if (!strcasecmp(val, "close"))
 296                         r->connection_close = true;
 297         } else if (!strcmp(data, "user-agent")) {
 298                 char *str;
 299
 300                 if (strstr(val, "Opera"))
 301                         r->ua = UH_UA_OPERA;
 302                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 303                         r->ua = UH_UA_MSIE_NEW;
 304                         if (str[5] && str[6] == '.') {
 305                                 switch (str[5]) {
 306                                 case '6':
 307                                         if (strstr(str, "SV1"))
 308                                                 break;
 309                                         /* fall through */
 310                                 case '5':
 311                                 case '4':
 312                                         r->ua = UH_UA_MSIE_OLD;
 313                                         break;
 314                                 }
 315                         }
 316                 }
 317                 else if (strstr(val, "Chrome/"))
 318                         r->ua = UH_UA_CHROME;
 319                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 320                         r->ua = UH_UA_SAFARI;
 321                 else if (strstr(val, "Gecko/"))
 322                         r->ua = UH_UA_GECKO;
 323                 else if (strstr(val, "Konqueror"))
 324                         r->ua = UH_UA_KONQUEROR;
 325         }
 326
 327
 328         blobmsg_add_string(&cl->hdr, data, val);
 329
 330         cl->state = CLIENT_STATE_HEADER;
 331 }
 332
 333 void client_poll_post_data(struct client *cl)
 334 {
 335         struct dispatch *d = &cl->dispatch;
 336         struct http_request *r = &cl->request;
 337         char *buf;
 338         int len;
 339
 340         if (cl->state == CLIENT_STATE_DONE)
 341                 return;
 342
 343         while (1) {
 344                 char *sep;
 345                 int offset = 0;
 346                 int cur_len;
 347
 348                 buf = ustream_get_read_buf(cl->us, &len);
 349                 if (!buf || !len)
 350                         break;
 351
 352                 if (!d->data_send)
 353                         return;
 354
 355                 cur_len = min(r->content_length, len);
 356                 if (cur_len) {
 357                         if (d->data_blocked)
 358                                 break;
 359
 360                         if (d->data_send)
 361                                 cur_len = d->data_send(cl, buf, cur_len);
 362
 363                         r->content_length -= cur_len;
 364                         ustream_consume(cl->us, cur_len);
 365                         continue;
 366                 }
 367
 368                 if (!r->transfer_chunked)
 369                         break;
 370
 371                 if (r->transfer_chunked > 1)
 372                         offset = 2;
 373
 374                 sep = strstr(buf + offset, "\r\n");
 375                 if (!sep)
 376                         break;
 377
 378                 *sep = 0;
 379
 380                 r->content_length = strtoul(buf + offset, &sep, 16);
 381                 r->transfer_chunked++;
 382                 ustream_consume(cl->us, sep + 2 - buf);
 383
 384                 /* invalid chunk length */
 385                 if (sep && *sep) {
 386                         r->content_length = 0;
 387                         r->transfer_chunked = 0;
 388                         break;
 389                 }
 390
 391                 /* empty chunk == eof */
 392                 if (!r->content_length) {
 393                         r->transfer_chunked = false;
 394                         break;
 395                 }
 396         }
 397
 398         buf = ustream_get_read_buf(cl->us, &len);
 399         if (!r->content_length && !r->transfer_chunked &&
 400                 cl->state != CLIENT_STATE_DONE) {
 401                 if (cl->dispatch.data_done)
 402                         cl->dispatch.data_done(cl);
 403
 404                 cl->state = CLIENT_STATE_DONE;
 405         }
 406 }
 407
 408 static bool client_data_cb(struct client *cl, char *buf, int len)
 409 {
 410         client_poll_post_data(cl);
 411         return false;
 412 }
 413
 414 static bool client_header_cb(struct client *cl, char *buf, int len)
 415 {
 416         char *newline;
 417         int line_len;
 418
 419         newline = strstr(buf, "\r\n");
 420         if (!newline)
 421                 return false;
 422
 423         *newline = 0;
 424         client_parse_header(cl, buf);
 425         line_len = newline + 2 - buf;
 426         ustream_consume(cl->us, line_len);
 427         if (cl->state == CLIENT_STATE_DATA)
 428                 return client_data_cb(cl, newline + 2, len - line_len);
 429
 430         return true;
 431 }
 432
 433 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 434 static read_cb_t read_cbs[] = {
 435         [CLIENT_STATE_INIT] = client_init_cb,
 436         [CLIENT_STATE_HEADER] = client_header_cb,
 437         [CLIENT_STATE_DATA] = client_data_cb,
 438 };
 439
 440 void uh_client_read_cb(struct client *cl)
 441 {
 442         struct ustream *us = cl->us;
 443         char *str;
 444         int len;
 445
 446         client_done = false;
 447         do {
 448                 str = ustream_get_read_buf(us, &len);
 449                 if (!str || !len)
 450                         break;
 451
 452                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 453                         break;
 454
 455                 if (!read_cbs[cl->state](cl, str, len)) {
 456                         if (len == us->r.buffer_len &&
 457                             cl->state != CLIENT_STATE_DATA)
 458                                 uh_header_error(cl, 413, "Request Entity Too Large");
 459                         break;
 460                 }
 461         } while (!client_done);
 462 }
 463
 464 static void client_close(struct client *cl)
 465 {
 466         client_done = true;
 467         n_clients--;
 468         uh_dispatch_done(cl);
 469         uloop_timeout_cancel(&cl->timeout);
 470         if (cl->tls)
 471                 uh_tls_client_detach(cl);
 472         ustream_free(&cl->sfd.stream);
 473         close(cl->sfd.fd.fd);
 474         list_del(&cl->list);
 475         blob_buf_free(&cl->hdr);
 476         free(cl);
 477
 478         uh_unblock_listeners();
 479 }
 480
 481 void uh_client_notify_state(struct client *cl)
 482 {
 483         struct ustream *s = cl->us;
 484
 485         if (!s->write_error) {
 486                 if (cl->state == CLIENT_STATE_DATA)
 487                         return;
 488
 489                 if (!s->eof || s->w.data_bytes)
 490                         return;
 491         }
 492
 493         return client_close(cl);
 494 }
 495
 496 static void client_ustream_read_cb(struct ustream *s, int bytes)
 497 {
 498         struct client *cl = container_of(s, struct client, sfd.stream);
 499
 500         uh_client_read_cb(cl);
 501 }
 502
 503 static void client_ustream_write_cb(struct ustream *s, int bytes)
 504 {
 505         struct client *cl = container_of(s, struct client, sfd.stream);
 506
 507         if (cl->dispatch.write_cb)
 508                 cl->dispatch.write_cb(cl);
 509 }
 510
 511 static void client_notify_state(struct ustream *s)
 512 {
 513         struct client *cl = container_of(s, struct client, sfd.stream);
 514
 515         uh_client_notify_state(cl);
 516 }
 517
 518 static void set_addr(struct uh_addr *addr, void *src)
 519 {
 520         struct sockaddr_in *sin = src;
 521         struct sockaddr_in6 *sin6 = src;
 522
 523         addr->family = sin->sin_family;
 524         if (addr->family == AF_INET) {
 525                 addr->port = ntohs(sin->sin_port);
 526                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 527         } else {
 528                 addr->port = ntohs(sin6->sin6_port);
 529                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 530         }
 531 }
 532
 533 bool uh_accept_client(int fd, bool tls)
 534 {
 535         static struct client *next_client;
 536         struct client *cl;
 537         unsigned int sl;
 538         int sfd;
 539         static int client_id = 0;
 540         struct sockaddr_in6 addr;
 541
 542         if (!next_client)
 543                 next_client = calloc(1, sizeof(*next_client));
 544
 545         cl = next_client;
 546
 547         sl = sizeof(addr);
 548         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 549         if (sfd < 0)
 550                 return false;
 551
 552         set_addr(&cl->peer_addr, &addr);
 553         sl = sizeof(addr);
 554         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 555         set_addr(&cl->srv_addr, &addr);
 556
 557         cl->us = &cl->sfd.stream;
 558         if (tls) {
 559                 uh_tls_client_attach(cl);
 560         } else {
 561                 cl->us->notify_read = client_ustream_read_cb;
 562                 cl->us->notify_write = client_ustream_write_cb;
 563                 cl->us->notify_state = client_notify_state;
 564         }
 565
 566         cl->us->string_data = true;
 567         ustream_fd_init(&cl->sfd, sfd);
 568
 569         uh_poll_connection(cl);
 570         list_add_tail(&cl->list, &clients);
 571
 572         next_client = NULL;
 573         n_clients++;
 574         cl->id = client_id++;
 575         cl->tls = tls;
 576
 577         return true;
 578 }
 579
 580 void uh_close_fds(void)
 581 {
 582         struct client *cl;
 583
 584         uloop_done();
 585         uh_close_listen_fds();
 586         list_for_each_entry(cl, &clients, list) {
 587                 close(cl->sfd.fd.fd);
 588                 if (cl->dispatch.close_fds)
 589                         cl->dispatch.close_fds(cl);
 590         }
 591 }