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