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