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         if (cl->dispatch.req_free)
  77                 cl->dispatch.req_free(cl);
  78 }
  79
  80 static void client_timeout(struct uloop_timeout *timeout)
  81 {
  82         struct client *cl = container_of(timeout, struct client, timeout);
  83
  84         cl->state = CLIENT_STATE_CLOSE;
  85         uh_connection_close(cl);
  86 }
  87
  88 static void uh_set_client_timeout(struct client *cl, int timeout)
  89 {
  90         cl->timeout.cb = client_timeout;
  91         uloop_timeout_set(&cl->timeout, timeout * 1000);
  92 }
  93
  94 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
  95 {
  96         struct client *cl = container_of(timeout, struct client, timeout);
  97         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
  98
  99         uh_set_client_timeout(cl, sec);
 100         cl->us->notify_read(cl->us, 0);
 101 }
 102
 103 static void uh_poll_connection(struct client *cl)
 104 {
 105         cl->timeout.cb = uh_keepalive_poll_cb;
 106         uloop_timeout_set(&cl->timeout, 1);
 107 }
 108
 109 void uh_request_done(struct client *cl)
 110 {
 111         uh_chunk_eof(cl);
 112         uh_dispatch_done(cl);
 113         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 114
 115         if (!conf.http_keepalive || cl->request.connection_close)
 116                 return uh_connection_close(cl);
 117
 118         cl->state = CLIENT_STATE_INIT;
 119         cl->requests++;
 120         uh_poll_connection(cl);
 121 }
 122
 123 void __printf(4, 5)
 124 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 125 {
 126         va_list arg;
 127
 128         uh_http_header(cl, code, summary);
 129         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 130
 131         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 132
 133         if (fmt) {
 134                 va_start(arg, fmt);
 135                 uh_chunk_vprintf(cl, fmt, arg);
 136                 va_end(arg);
 137         }
 138
 139         uh_request_done(cl);
 140 }
 141
 142 static void uh_header_error(struct client *cl, int code, const char *summary)
 143 {
 144         uh_client_error(cl, code, summary, NULL);
 145         uh_connection_close(cl);
 146 }
 147
 148 static int find_idx(const char * const *list, int max, const char *str)
 149 {
 150         int i;
 151
 152         for (i = 0; i < max; i++)
 153                 if (!strcmp(list[i], str))
 154                         return i;
 155
 156         return -1;
 157 }
 158
 159 static int client_parse_request(struct client *cl, char *data)
 160 {
 161         struct http_request *req = &cl->request;
 162         char *type, *path, *version;
 163         int h_method, h_version;
 164
 165         type = strtok(data, " ");
 166         path = strtok(NULL, " ");
 167         version = strtok(NULL, " ");
 168         if (!type || !path || !version)
 169                 return CLIENT_STATE_DONE;
 170
 171         blobmsg_add_string(&cl->hdr, "URL", path);
 172
 173         memset(&cl->request, 0, sizeof(cl->request));
 174         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 175         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 176         if (h_method < 0 || h_version < 0) {
 177                 req->version = UH_HTTP_VER_1_0;
 178                 return CLIENT_STATE_DONE;
 179         }
 180
 181         req->method = h_method;
 182         req->version = h_version;
 183         if (req->version < UH_HTTP_VER_1_1 || req->method == UH_HTTP_MSG_POST ||
 184             !conf.http_keepalive)
 185                 req->connection_close = true;
 186
 187         return CLIENT_STATE_HEADER;
 188 }
 189
 190 static bool client_init_cb(struct client *cl, char *buf, int len)
 191 {
 192         char *newline;
 193
 194         newline = strstr(buf, "\r\n");
 195         if (!newline)
 196                 return false;
 197
 198         if (newline == buf) {
 199                 ustream_consume(cl->us, 2);
 200                 return true;
 201         }
 202
 203         *newline = 0;
 204         blob_buf_init(&cl->hdr, 0);
 205         cl->state = client_parse_request(cl, buf);
 206         ustream_consume(cl->us, newline + 2 - buf);
 207         if (cl->state == CLIENT_STATE_DONE)
 208                 uh_header_error(cl, 400, "Bad Request");
 209
 210         return true;
 211 }
 212
 213 static bool rfc1918_filter_check(struct client *cl)
 214 {
 215         if (!conf.rfc1918_filter)
 216                 return true;
 217
 218         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 219                 return true;
 220
 221         uh_client_error(cl, 403, "Forbidden",
 222                         "Rejected request from RFC1918 IP "
 223                         "to public server address");
 224         return false;
 225 }
 226
 227 static void client_header_complete(struct client *cl)
 228 {
 229         struct http_request *r = &cl->request;
 230
 231         if (!rfc1918_filter_check(cl))
 232                 return;
 233
 234         if (r->expect_cont)
 235                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 236
 237         switch(r->ua) {
 238         case UH_UA_MSIE_OLD:
 239                 if (r->method != UH_HTTP_MSG_POST)
 240                         break;
 241
 242                 /* fall through */
 243         case UH_UA_SAFARI:
 244                 r->connection_close = true;
 245                 break;
 246         default:
 247                 break;
 248         }
 249
 250         uh_handle_request(cl);
 251 }
 252
 253 static void client_parse_header(struct client *cl, char *data)
 254 {
 255         struct http_request *r = &cl->request;
 256         char *err;
 257         char *name;
 258         char *val;
 259
 260         if (!*data) {
 261                 uloop_timeout_cancel(&cl->timeout);
 262                 cl->state = CLIENT_STATE_DATA;
 263                 client_header_complete(cl);
 264                 return;
 265         }
 266
 267         val = uh_split_header(data);
 268         if (!val) {
 269                 cl->state = CLIENT_STATE_DONE;
 270                 return;
 271         }
 272
 273         for (name = data; *name; name++)
 274                 if (isupper(*name))
 275                         *name = tolower(*name);
 276
 277         if (!strcmp(data, "expect")) {
 278                 if (!strcasecmp(val, "100-continue"))
 279                         r->expect_cont = true;
 280                 else {
 281                         uh_header_error(cl, 412, "Precondition Failed");
 282                         return;
 283                 }
 284         } else if (!strcmp(data, "content-length")) {
 285                 r->content_length = strtoul(val, &err, 0);
 286                 if (err && *err) {
 287                         uh_header_error(cl, 400, "Bad Request");
 288                         return;
 289                 }
 290         } else if (!strcmp(data, "transfer-encoding")) {
 291                 if (!strcmp(val, "chunked"))
 292                         r->transfer_chunked = true;
 293         } else if (!strcmp(data, "connection")) {
 294                 if (!strcasecmp(val, "close"))
 295                         r->connection_close = true;
 296                 else if (!strcasecmp(val, "keep-alive"))
 297                         r->connection_close = false;
 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                 } else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 318                         r->ua = UH_UA_SAFARI;
 319                 else if (strstr(val, "Chrome/"))
 320                         r->ua = UH_UA_CHROME;
 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         do {
 447                 str = ustream_get_read_buf(us, &len);
 448                 if (!str || !len)
 449                         break;
 450
 451                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 452                         break;
 453
 454                 if (!read_cbs[cl->state](cl, str, len)) {
 455                         if (len == us->r.buffer_len &&
 456                             cl->state != CLIENT_STATE_DATA)
 457                                 uh_header_error(cl, 413, "Request Entity Too Large");
 458                         break;
 459                 }
 460         } while(1);
 461 }
 462
 463 static void client_close(struct client *cl)
 464 {
 465         n_clients--;
 466         uh_dispatch_done(cl);
 467         uloop_timeout_cancel(&cl->timeout);
 468         if (cl->tls)
 469                 uh_tls_client_detach(cl);
 470         ustream_free(&cl->sfd.stream);
 471         close(cl->sfd.fd.fd);
 472         list_del(&cl->list);
 473         blob_buf_free(&cl->hdr);
 474         free(cl);
 475
 476         uh_unblock_listeners();
 477 }
 478
 479 void uh_client_notify_state(struct client *cl)
 480 {
 481         struct ustream *s = cl->us;
 482
 483         if (!s->write_error) {
 484                 if (cl->state == CLIENT_STATE_DATA)
 485                         return;
 486
 487                 if (!s->eof || s->w.data_bytes)
 488                         return;
 489         }
 490
 491         return client_close(cl);
 492 }
 493
 494 static void client_ustream_read_cb(struct ustream *s, int bytes)
 495 {
 496         struct client *cl = container_of(s, struct client, sfd.stream);
 497
 498         uh_client_read_cb(cl);
 499 }
 500
 501 static void client_ustream_write_cb(struct ustream *s, int bytes)
 502 {
 503         struct client *cl = container_of(s, struct client, sfd.stream);
 504
 505         if (cl->dispatch.write_cb)
 506                 cl->dispatch.write_cb(cl);
 507 }
 508
 509 static void client_notify_state(struct ustream *s)
 510 {
 511         struct client *cl = container_of(s, struct client, sfd.stream);
 512
 513         uh_client_notify_state(cl);
 514 }
 515
 516 static void set_addr(struct uh_addr *addr, void *src)
 517 {
 518         struct sockaddr_in *sin = src;
 519         struct sockaddr_in6 *sin6 = src;
 520
 521         addr->family = sin->sin_family;
 522         if (addr->family == AF_INET) {
 523                 addr->port = ntohs(sin->sin_port);
 524                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 525         } else {
 526                 addr->port = ntohs(sin6->sin6_port);
 527                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 528         }
 529 }
 530
 531 bool uh_accept_client(int fd, bool tls)
 532 {
 533         static struct client *next_client;
 534         struct client *cl;
 535         unsigned int sl;
 536         int sfd;
 537         static int client_id = 0;
 538         struct sockaddr_in6 addr;
 539
 540         if (!next_client)
 541                 next_client = calloc(1, sizeof(*next_client));
 542
 543         cl = next_client;
 544
 545         sl = sizeof(addr);
 546         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 547         if (sfd < 0)
 548                 return false;
 549
 550         set_addr(&cl->peer_addr, &addr);
 551         sl = sizeof(addr);
 552         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 553         set_addr(&cl->srv_addr, &addr);
 554
 555         cl->us = &cl->sfd.stream;
 556         if (tls) {
 557                 uh_tls_client_attach(cl);
 558         } else {
 559                 cl->us->notify_read = client_ustream_read_cb;
 560                 cl->us->notify_write = client_ustream_write_cb;
 561                 cl->us->notify_state = client_notify_state;
 562         }
 563
 564         cl->us->string_data = true;
 565         ustream_fd_init(&cl->sfd, sfd);
 566
 567         uh_poll_connection(cl);
 568         list_add_tail(&cl->list, &clients);
 569
 570         next_client = NULL;
 571         n_clients++;
 572         cl->id = client_id++;
 573         cl->tls = tls;
 574
 575         return true;
 576 }
 577
 578 void uh_close_fds(void)
 579 {
 580         struct client *cl;
 581
 582         uloop_done();
 583         uh_close_listen_fds();
 584         list_for_each_entry(cl, &clients, list) {
 585                 close(cl->sfd.fd.fd);
 586                 if (cl->dispatch.close_fds)
 587                         cl->dispatch.close_fds(cl);
 588         }
 589 }