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