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