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         cl->request.connection_close = true;
  99         uh_request_done(cl);
 100 }
 101
 102 static void uh_set_client_timeout(struct client *cl, int timeout)
 103 {
 104         cl->timeout.cb = client_timeout;
 105         uloop_timeout_set(&cl->timeout, timeout * 1000);
 106 }
 107
 108 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
 109 {
 110         struct client *cl = container_of(timeout, struct client, timeout);
 111         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
 112
 113         uh_set_client_timeout(cl, sec);
 114         cl->us->notify_read(cl->us, 0);
 115 }
 116
 117 static void uh_poll_connection(struct client *cl)
 118 {
 119         cl->timeout.cb = uh_keepalive_poll_cb;
 120         uloop_timeout_set(&cl->timeout, 1);
 121 }
 122
 123 void uh_request_done(struct client *cl)
 124 {
 125         uh_chunk_eof(cl);
 126         uh_dispatch_done(cl);
 127         blob_buf_init(&cl->hdr_response, 0);
 128         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 129
 130         if (!conf.http_keepalive || cl->request.connection_close)
 131                 return uh_connection_close(cl);
 132
 133         cl->state = CLIENT_STATE_INIT;
 134         cl->requests++;
 135         uh_poll_connection(cl);
 136 }
 137
 138 void __printf(4, 5)
 139 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 140 {
 141         struct http_request *r = &cl->request;
 142         va_list arg;
 143
 144         uh_http_header(cl, code, summary);
 145         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 146
 147         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 148
 149         if (fmt) {
 150                 va_start(arg, fmt);
 151                 uh_chunk_vprintf(cl, fmt, arg);
 152                 va_end(arg);
 153         }
 154
 155         /* Close the connection even when keep alive is set, when it
 156          * contains a request body, as it was not read and we are
 157          * currently out of sync. Without handling this the body will be
 158          * interpreted as part of the next request. The alternative
 159          * would be to read and discard the request body here.
 160          */
 161         if (r->transfer_chunked || r->content_length > 0) {
 162                 cl->state = CLIENT_STATE_CLOSE;
 163                 cl->request.connection_close = true;
 164         }
 165
 166         uh_request_done(cl);
 167 }
 168
 169 static void uh_header_error(struct client *cl, int code, const char *summary)
 170 {
 171         uh_client_error(cl, code, summary, NULL);
 172         uh_connection_close(cl);
 173 }
 174
 175 static int find_idx(const char * const *list, int max, const char *str)
 176 {
 177         int i;
 178
 179         for (i = 0; i < max; i++)
 180                 if (!strcmp(list[i], str))
 181                         return i;
 182
 183         return -1;
 184 }
 185
 186 static int client_parse_request(struct client *cl, char *data)
 187 {
 188         struct http_request *req = &cl->request;
 189         char *type, *path, *version;
 190         int h_method, h_version;
 191
 192         type = strtok(data, " ");
 193         path = strtok(NULL, " ");
 194         version = strtok(NULL, " ");
 195         if (!type || !path || !version)
 196                 return CLIENT_STATE_DONE;
 197
 198         blobmsg_add_string(&cl->hdr, "URL", path);
 199
 200         memset(&cl->request, 0, sizeof(cl->request));
 201         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 202         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 203         if (h_method < 0 || h_version < 0) {
 204                 req->version = UH_HTTP_VER_1_0;
 205                 return CLIENT_STATE_DONE;
 206         }
 207
 208         req->method = h_method;
 209         req->version = h_version;
 210         if (req->version < UH_HTTP_VER_1_1 || !conf.http_keepalive)
 211                 req->connection_close = true;
 212
 213         return CLIENT_STATE_HEADER;
 214 }
 215
 216 static bool client_init_cb(struct client *cl, char *buf, int len)
 217 {
 218         char *newline;
 219
 220         newline = strstr(buf, "\r\n");
 221         if (!newline)
 222                 return false;
 223
 224         if (newline == buf) {
 225                 ustream_consume(cl->us, 2);
 226                 return true;
 227         }
 228
 229         *newline = 0;
 230         blob_buf_init(&cl->hdr, 0);
 231         cl->state = client_parse_request(cl, buf);
 232         ustream_consume(cl->us, newline + 2 - buf);
 233         if (cl->state == CLIENT_STATE_DONE)
 234                 uh_header_error(cl, 400, "Bad Request");
 235
 236         return true;
 237 }
 238
 239 static bool rfc1918_filter_check(struct client *cl)
 240 {
 241         if (!conf.rfc1918_filter)
 242                 return true;
 243
 244         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 245                 return true;
 246
 247         uh_client_error(cl, 403, "Forbidden",
 248                         "Rejected request from RFC1918 IP "
 249                         "to public server address");
 250         return false;
 251 }
 252
 253 static bool tls_redirect_check(struct client *cl)
 254 {
 255         int rem, port;
 256         struct blob_attr *cur;
 257         char *ptr, *url = NULL, *host = NULL;
 258
 259         if (cl->tls || !conf.tls_redirect)
 260                 return true;
 261
 262         if ((port = uh_first_tls_port(cl->srv_addr.family)) == -1)
 263                 return true;
 264
 265         blob_for_each_attr(cur, cl->hdr.head, rem) {
 266                 if (!strncmp(blobmsg_name(cur), "host", 4))
 267                         host = blobmsg_get_string(cur);
 268
 269                 if (!strncmp(blobmsg_name(cur), "URL", 3))
 270                         url = blobmsg_get_string(cur);
 271
 272                 if (url && host)
 273                         break;
 274         }
 275
 276         if (!url || !host)
 277                 return true;
 278
 279         if ((ptr = strchr(host, ']')) != NULL)
 280                 *(ptr+1) = 0;
 281         else if ((ptr = strchr(host, ':')) != NULL)
 282                 *ptr = 0;
 283
 284         cl->request.disable_chunked = true;
 285         cl->request.connection_close = true;
 286
 287         uh_http_header(cl, 307, "Temporary Redirect");
 288
 289         if (port != 443)
 290                 ustream_printf(cl->us, "Location: https://%s:%d%s\r\n\r\n", host, port, url);
 291         else
 292                 ustream_printf(cl->us, "Location: https://%s%s\r\n\r\n", host, url);
 293
 294         uh_request_done(cl);
 295
 296         return false;
 297 }
 298
 299 static void client_header_complete(struct client *cl)
 300 {
 301         struct http_request *r = &cl->request;
 302
 303         if (!rfc1918_filter_check(cl))
 304                 return;
 305
 306         if (!tls_redirect_check(cl))
 307                 return;
 308
 309         if (r->expect_cont)
 310                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 311
 312         switch(r->ua) {
 313         case UH_UA_MSIE_OLD:
 314                 if (r->method != UH_HTTP_MSG_POST)
 315                         break;
 316
 317                 /* fall through */
 318         case UH_UA_SAFARI:
 319                 r->connection_close = true;
 320                 break;
 321         default:
 322                 break;
 323         }
 324
 325         uh_handle_request(cl);
 326 }
 327
 328 static void client_parse_header(struct client *cl, char *data)
 329 {
 330         struct http_request *r = &cl->request;
 331         char *err;
 332         char *name;
 333         char *val;
 334
 335         if (!*data) {
 336                 uloop_timeout_cancel(&cl->timeout);
 337                 cl->state = CLIENT_STATE_DATA;
 338                 client_header_complete(cl);
 339                 return;
 340         }
 341
 342         val = uh_split_header(data);
 343         if (!val) {
 344                 cl->state = CLIENT_STATE_DONE;
 345                 return;
 346         }
 347
 348         for (name = data; *name; name++)
 349                 if (isupper(*name))
 350                         *name = tolower(*name);
 351
 352         if (!strcmp(data, "expect")) {
 353                 if (!strcasecmp(val, "100-continue"))
 354                         r->expect_cont = true;
 355                 else {
 356                         uh_header_error(cl, 412, "Precondition Failed");
 357                         return;
 358                 }
 359         } else if (!strcmp(data, "content-length")) {
 360                 r->content_length = strtoul(val, &err, 0);
 361                 if ((err && *err) || r->content_length < 0) {
 362                         uh_header_error(cl, 400, "Bad Request");
 363                         return;
 364                 }
 365         } else if (!strcmp(data, "transfer-encoding")) {
 366                 if (!strcmp(val, "chunked"))
 367                         r->transfer_chunked = true;
 368         } else if (!strcmp(data, "connection")) {
 369                 if (!strcasecmp(val, "close"))
 370                         r->connection_close = true;
 371         } else if (!strcmp(data, "user-agent")) {
 372                 char *str;
 373
 374                 if (strstr(val, "Opera"))
 375                         r->ua = UH_UA_OPERA;
 376                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 377                         r->ua = UH_UA_MSIE_NEW;
 378                         if (str[5] && str[6] == '.') {
 379                                 switch (str[5]) {
 380                                 case '6':
 381                                         if (strstr(str, "SV1"))
 382                                                 break;
 383                                         /* fall through */
 384                                 case '5':
 385                                 case '4':
 386                                         r->ua = UH_UA_MSIE_OLD;
 387                                         break;
 388                                 }
 389                         }
 390                 }
 391                 else if (strstr(val, "Chrome/"))
 392                         r->ua = UH_UA_CHROME;
 393                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 394                         r->ua = UH_UA_SAFARI;
 395                 else if (strstr(val, "Gecko/"))
 396                         r->ua = UH_UA_GECKO;
 397                 else if (strstr(val, "Konqueror"))
 398                         r->ua = UH_UA_KONQUEROR;
 399         }
 400
 401
 402         blobmsg_add_string(&cl->hdr, data, val);
 403
 404         cl->state = CLIENT_STATE_HEADER;
 405 }
 406
 407 void client_poll_post_data(struct client *cl)
 408 {
 409         struct dispatch *d = &cl->dispatch;
 410         struct http_request *r = &cl->request;
 411         enum client_state st;
 412         char *buf;
 413         int len;
 414
 415         if (cl->state == CLIENT_STATE_DONE)
 416                 return;
 417
 418         while (1) {
 419                 char *sep;
 420                 int offset = 0;
 421                 int cur_len;
 422
 423                 buf = ustream_get_read_buf(cl->us, &len);
 424                 if (!buf || !len)
 425                         break;
 426
 427                 if (!d->data_send)
 428                         return;
 429
 430                 cur_len = min(r->content_length, len);
 431                 if (cur_len) {
 432                         if (d->data_blocked)
 433                                 break;
 434
 435                         if (d->data_send)
 436                                 cur_len = d->data_send(cl, buf, cur_len);
 437
 438                         r->content_length -= cur_len;
 439                         ustream_consume(cl->us, cur_len);
 440                         continue;
 441                 }
 442
 443                 if (!r->transfer_chunked)
 444                         break;
 445
 446                 if (r->transfer_chunked > 1)
 447                         offset = 2;
 448
 449                 sep = strstr(buf + offset, "\r\n");
 450                 if (!sep)
 451                         break;
 452
 453                 *sep = 0;
 454
 455                 r->content_length = strtoul(buf + offset, &sep, 16);
 456                 r->transfer_chunked++;
 457                 ustream_consume(cl->us, sep + 2 - buf);
 458
 459                 /* invalid chunk length */
 460                 if ((sep && *sep) || r->content_length < 0) {
 461                         r->content_length = 0;
 462                         r->transfer_chunked = 0;
 463                         break;
 464                 }
 465
 466                 /* empty chunk == eof */
 467                 if (!r->content_length) {
 468                         r->transfer_chunked = false;
 469                         break;
 470                 }
 471         }
 472
 473         buf = ustream_get_read_buf(cl->us, &len);
 474         if (!r->content_length && !r->transfer_chunked &&
 475                 cl->state != CLIENT_STATE_DONE) {
 476                 st = cl->state;
 477
 478                 if (cl->dispatch.data_done)
 479                         cl->dispatch.data_done(cl);
 480
 481                 if (cl->state == st)
 482                         cl->state = CLIENT_STATE_DONE;
 483         }
 484 }
 485
 486 static bool client_data_cb(struct client *cl, char *buf, int len)
 487 {
 488         client_poll_post_data(cl);
 489         return false;
 490 }
 491
 492 static bool client_header_cb(struct client *cl, char *buf, int len)
 493 {
 494         char *newline;
 495         int line_len;
 496
 497         newline = strstr(buf, "\r\n");
 498         if (!newline)
 499                 return false;
 500
 501         *newline = 0;
 502         client_parse_header(cl, buf);
 503         line_len = newline + 2 - buf;
 504         ustream_consume(cl->us, line_len);
 505         if (cl->state == CLIENT_STATE_DATA)
 506                 return client_data_cb(cl, newline + 2, len - line_len);
 507
 508         return true;
 509 }
 510
 511 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 512 static read_cb_t read_cbs[] = {
 513         [CLIENT_STATE_INIT] = client_init_cb,
 514         [CLIENT_STATE_HEADER] = client_header_cb,
 515         [CLIENT_STATE_DATA] = client_data_cb,
 516 };
 517
 518 void uh_client_read_cb(struct client *cl)
 519 {
 520         struct ustream *us = cl->us;
 521         char *str;
 522         int len;
 523
 524         client_done = false;
 525         do {
 526                 str = ustream_get_read_buf(us, &len);
 527                 if (!str || !len)
 528                         break;
 529
 530                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 531                         break;
 532
 533                 if (!read_cbs[cl->state](cl, str, len)) {
 534                         if (len == us->r.buffer_len &&
 535                             cl->state != CLIENT_STATE_DATA &&
 536                             cl->state != CLIENT_STATE_DONE)
 537                                 uh_header_error(cl, 413, "Request Entity Too Large");
 538                         break;
 539                 }
 540         } while (!client_done);
 541 }
 542
 543 static void client_close(struct client *cl)
 544 {
 545         if (cl->refcount) {
 546                 cl->state = CLIENT_STATE_CLEANUP;
 547                 return;
 548         }
 549
 550         client_done = true;
 551         n_clients--;
 552         uh_dispatch_done(cl);
 553         uloop_timeout_cancel(&cl->timeout);
 554         if (cl->tls)
 555                 uh_tls_client_detach(cl);
 556         ustream_free(&cl->sfd.stream);
 557         close(cl->sfd.fd.fd);
 558         list_del(&cl->list);
 559         blob_buf_free(&cl->hdr);
 560         blob_buf_free(&cl->hdr_response);
 561         free(cl);
 562
 563         uh_unblock_listeners();
 564 }
 565
 566 void uh_client_notify_state(struct client *cl)
 567 {
 568         struct ustream *s = cl->us;
 569
 570         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
 571                 if (cl->state == CLIENT_STATE_DATA)
 572                         return;
 573
 574                 if (!s->eof || s->w.data_bytes)
 575                         return;
 576
 577 #ifdef HAVE_TLS
 578                 if (cl->tls && cl->ssl.conn && cl->ssl.conn->w.data_bytes) {
 579                         cl->ssl.conn->eof = s->eof;
 580                         if (!ustream_write_pending(cl->ssl.conn))
 581                                 return;
 582                 }
 583 #endif
 584         }
 585
 586         return client_close(cl);
 587 }
 588
 589 static void client_ustream_read_cb(struct ustream *s, int bytes)
 590 {
 591         struct client *cl = container_of(s, struct client, sfd.stream);
 592
 593         uh_client_read_cb(cl);
 594 }
 595
 596 static void client_ustream_write_cb(struct ustream *s, int bytes)
 597 {
 598         struct client *cl = container_of(s, struct client, sfd.stream);
 599
 600         if (cl->dispatch.write_cb)
 601                 cl->dispatch.write_cb(cl);
 602 }
 603
 604 static void client_notify_state(struct ustream *s)
 605 {
 606         struct client *cl = container_of(s, struct client, sfd.stream);
 607
 608         uh_client_notify_state(cl);
 609 }
 610
 611 static void set_addr(struct uh_addr *addr, void *src)
 612 {
 613         struct sockaddr_in *sin = src;
 614         struct sockaddr_in6 *sin6 = src;
 615
 616         addr->family = sin->sin_family;
 617         if (addr->family == AF_INET) {
 618                 addr->port = ntohs(sin->sin_port);
 619                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 620         } else {
 621                 addr->port = ntohs(sin6->sin6_port);
 622                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 623         }
 624 }
 625
 626 bool uh_accept_client(int fd, bool tls)
 627 {
 628         static struct client *next_client;
 629         struct client *cl;
 630         unsigned int sl;
 631         int sfd;
 632         static int client_id = 0;
 633         struct sockaddr_in6 addr;
 634
 635         if (!next_client)
 636                 next_client = calloc(1, sizeof(*next_client));
 637
 638         cl = next_client;
 639
 640         sl = sizeof(addr);
 641         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 642         if (sfd < 0)
 643                 return false;
 644
 645         set_addr(&cl->peer_addr, &addr);
 646         sl = sizeof(addr);
 647         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 648         set_addr(&cl->srv_addr, &addr);
 649
 650         cl->us = &cl->sfd.stream;
 651         if (tls) {
 652                 uh_tls_client_attach(cl);
 653         } else {
 654                 cl->us->notify_read = client_ustream_read_cb;
 655                 cl->us->notify_write = client_ustream_write_cb;
 656                 cl->us->notify_state = client_notify_state;
 657         }
 658
 659         cl->us->string_data = true;
 660         ustream_fd_init(&cl->sfd, sfd);
 661
 662         uh_poll_connection(cl);
 663         list_add_tail(&cl->list, &clients);
 664
 665         next_client = NULL;
 666         n_clients++;
 667         cl->id = client_id++;
 668         cl->tls = tls;
 669
 670         return true;
 671 }
 672
 673 void uh_close_fds(void)
 674 {
 675         struct client *cl;
 676
 677         uloop_done();
 678         uh_close_listen_fds();
 679         list_for_each_entry(cl, &clients, list) {
 680                 close(cl->sfd.fd.fd);
 681                 if (cl->dispatch.close_fds)
 682                         cl->dispatch.close_fds(cl);
 683         }
 684 }