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