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 || !conf.http_keepalive)
 184                 req->connection_close = true;
 185
 186         return CLIENT_STATE_HEADER;
 187 }
 188
 189 static bool client_init_cb(struct client *cl, char *buf, int len)
 190 {
 191         char *newline;
 192
 193         newline = strstr(buf, "\r\n");
 194         if (!newline)
 195                 return false;
 196
 197         if (newline == buf) {
 198                 ustream_consume(cl->us, 2);
 199                 return true;
 200         }
 201
 202         *newline = 0;
 203         blob_buf_init(&cl->hdr, 0);
 204         cl->state = client_parse_request(cl, buf);
 205         ustream_consume(cl->us, newline + 2 - buf);
 206         if (cl->state == CLIENT_STATE_DONE)
 207                 uh_header_error(cl, 400, "Bad Request");
 208
 209         return true;
 210 }
 211
 212 static bool rfc1918_filter_check(struct client *cl)
 213 {
 214         if (!conf.rfc1918_filter)
 215                 return true;
 216
 217         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 218                 return true;
 219
 220         uh_client_error(cl, 403, "Forbidden",
 221                         "Rejected request from RFC1918 IP "
 222                         "to public server address");
 223         return false;
 224 }
 225
 226 static void client_header_complete(struct client *cl)
 227 {
 228         struct http_request *r = &cl->request;
 229
 230         if (!rfc1918_filter_check(cl))
 231                 return;
 232
 233         if (r->expect_cont)
 234                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 235
 236         switch(r->ua) {
 237         case UH_UA_MSIE_OLD:
 238                 if (r->method != UH_HTTP_MSG_POST)
 239                         break;
 240
 241                 /* fall through */
 242         case UH_UA_SAFARI:
 243                 r->connection_close = true;
 244                 break;
 245         default:
 246                 break;
 247         }
 248
 249         uh_handle_request(cl);
 250 }
 251
 252 static void client_parse_header(struct client *cl, char *data)
 253 {
 254         struct http_request *r = &cl->request;
 255         char *err;
 256         char *name;
 257         char *val;
 258
 259         if (!*data) {
 260                 uloop_timeout_cancel(&cl->timeout);
 261                 cl->state = CLIENT_STATE_DATA;
 262                 client_header_complete(cl);
 263                 return;
 264         }
 265
 266         val = uh_split_header(data);
 267         if (!val) {
 268                 cl->state = CLIENT_STATE_DONE;
 269                 return;
 270         }
 271
 272         for (name = data; *name; name++)
 273                 if (isupper(*name))
 274                         *name = tolower(*name);
 275
 276         if (!strcmp(data, "expect")) {
 277                 if (!strcasecmp(val, "100-continue"))
 278                         r->expect_cont = true;
 279                 else {
 280                         uh_header_error(cl, 412, "Precondition Failed");
 281                         return;
 282                 }
 283         } else if (!strcmp(data, "content-length")) {
 284                 r->content_length = strtoul(val, &err, 0);
 285                 if (err && *err) {
 286                         uh_header_error(cl, 400, "Bad Request");
 287                         return;
 288                 }
 289         } else if (!strcmp(data, "transfer-encoding")) {
 290                 if (!strcmp(val, "chunked"))
 291                         r->transfer_chunked = true;
 292         } else if (!strcmp(data, "connection")) {
 293                 if (!strcasecmp(val, "close"))
 294                         r->connection_close = true;
 295                 else if (!strcasecmp(val, "keep-alive"))
 296                         r->connection_close = false;
 297         } else if (!strcmp(data, "user-agent")) {
 298                 char *str;
 299
 300                 if (strstr(val, "Opera"))
 301                         r->ua = UH_UA_OPERA;
 302                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 303                         r->ua = UH_UA_MSIE_NEW;
 304                         if (str[5] && str[6] == '.') {
 305                                 switch (str[5]) {
 306                                 case '6':
 307                                         if (strstr(str, "SV1"))
 308                                                 break;
 309                                         /* fall through */
 310                                 case '5':
 311                                 case '4':
 312                                         r->ua = UH_UA_MSIE_OLD;
 313                                         break;
 314                                 }
 315                         }
 316                 } else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 317                         r->ua = UH_UA_SAFARI;
 318                 else if (strstr(val, "Chrome/"))
 319                         r->ua = UH_UA_CHROME;
 320                 else if (strstr(val, "Gecko/"))
 321                         r->ua = UH_UA_GECKO;
 322                 else if (strstr(val, "Konqueror"))
 323                         r->ua = UH_UA_KONQUEROR;
 324         }
 325
 326
 327         blobmsg_add_string(&cl->hdr, data, val);
 328
 329         cl->state = CLIENT_STATE_HEADER;
 330 }
 331
 332 void client_poll_post_data(struct client *cl)
 333 {
 334         struct dispatch *d = &cl->dispatch;
 335         struct http_request *r = &cl->request;
 336         char *buf;
 337         int len;
 338
 339         if (cl->state == CLIENT_STATE_DONE)
 340                 return;
 341
 342         while (1) {
 343                 char *sep;
 344                 int offset = 0;
 345                 int cur_len;
 346
 347                 buf = ustream_get_read_buf(cl->us, &len);
 348                 if (!buf || !len)
 349                         break;
 350
 351                 if (!d->data_send)
 352                         return;
 353
 354                 cur_len = min(r->content_length, len);
 355                 if (cur_len) {
 356                         if (d->data_blocked)
 357                                 break;
 358
 359                         if (d->data_send)
 360                                 cur_len = d->data_send(cl, buf, cur_len);
 361
 362                         r->content_length -= cur_len;
 363                         ustream_consume(cl->us, cur_len);
 364                         continue;
 365                 }
 366
 367                 if (!r->transfer_chunked)
 368                         break;
 369
 370                 if (r->transfer_chunked > 1)
 371                         offset = 2;
 372
 373                 sep = strstr(buf + offset, "\r\n");
 374                 if (!sep)
 375                         break;
 376
 377                 *sep = 0;
 378
 379                 r->content_length = strtoul(buf + offset, &sep, 16);
 380                 r->transfer_chunked++;
 381                 ustream_consume(cl->us, sep + 2 - buf);
 382
 383                 /* invalid chunk length */
 384                 if (sep && *sep) {
 385                         r->content_length = 0;
 386                         r->transfer_chunked = 0;
 387                         break;
 388                 }
 389
 390                 /* empty chunk == eof */
 391                 if (!r->content_length) {
 392                         r->transfer_chunked = false;
 393                         break;
 394                 }
 395         }
 396
 397         buf = ustream_get_read_buf(cl->us, &len);
 398         if (!r->content_length && !r->transfer_chunked &&
 399                 cl->state != CLIENT_STATE_DONE) {
 400                 if (cl->dispatch.data_done)
 401                         cl->dispatch.data_done(cl);
 402
 403                 cl->state = CLIENT_STATE_DONE;
 404         }
 405 }
 406
 407 static bool client_data_cb(struct client *cl, char *buf, int len)
 408 {
 409         client_poll_post_data(cl);
 410         return false;
 411 }
 412
 413 static bool client_header_cb(struct client *cl, char *buf, int len)
 414 {
 415         char *newline;
 416         int line_len;
 417
 418         newline = strstr(buf, "\r\n");
 419         if (!newline)
 420                 return false;
 421
 422         *newline = 0;
 423         client_parse_header(cl, buf);
 424         line_len = newline + 2 - buf;
 425         ustream_consume(cl->us, line_len);
 426         if (cl->state == CLIENT_STATE_DATA)
 427                 return client_data_cb(cl, newline + 2, len - line_len);
 428
 429         return true;
 430 }
 431
 432 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 433 static read_cb_t read_cbs[] = {
 434         [CLIENT_STATE_INIT] = client_init_cb,
 435         [CLIENT_STATE_HEADER] = client_header_cb,
 436         [CLIENT_STATE_DATA] = client_data_cb,
 437 };
 438
 439 void uh_client_read_cb(struct client *cl)
 440 {
 441         struct ustream *us = cl->us;
 442         char *str;
 443         int len;
 444
 445         do {
 446                 str = ustream_get_read_buf(us, &len);
 447                 if (!str || !len)
 448                         break;
 449
 450                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 451                         break;
 452
 453                 if (!read_cbs[cl->state](cl, str, len)) {
 454                         if (len == us->r.buffer_len &&
 455                             cl->state != CLIENT_STATE_DATA)
 456                                 uh_header_error(cl, 413, "Request Entity Too Large");
 457                         break;
 458                 }
 459         } while(1);
 460 }
 461
 462 static void client_close(struct client *cl)
 463 {
 464         n_clients--;
 465         uh_dispatch_done(cl);
 466         uloop_timeout_cancel(&cl->timeout);
 467         if (cl->tls)
 468                 uh_tls_client_detach(cl);
 469         ustream_free(&cl->sfd.stream);
 470         close(cl->sfd.fd.fd);
 471         list_del(&cl->list);
 472         blob_buf_free(&cl->hdr);
 473         free(cl);
 474
 475         uh_unblock_listeners();
 476 }
 477
 478 void uh_client_notify_state(struct client *cl)
 479 {
 480         struct ustream *s = cl->us;
 481
 482         if (!s->write_error) {
 483                 if (cl->state == CLIENT_STATE_DATA)
 484                         return;
 485
 486                 if (!s->eof || s->w.data_bytes)
 487                         return;
 488         }
 489
 490         return client_close(cl);
 491 }
 492
 493 static void client_ustream_read_cb(struct ustream *s, int bytes)
 494 {
 495         struct client *cl = container_of(s, struct client, sfd.stream);
 496
 497         uh_client_read_cb(cl);
 498 }
 499
 500 static void client_ustream_write_cb(struct ustream *s, int bytes)
 501 {
 502         struct client *cl = container_of(s, struct client, sfd.stream);
 503
 504         if (cl->dispatch.write_cb)
 505                 cl->dispatch.write_cb(cl);
 506 }
 507
 508 static void client_notify_state(struct ustream *s)
 509 {
 510         struct client *cl = container_of(s, struct client, sfd.stream);
 511
 512         uh_client_notify_state(cl);
 513 }
 514
 515 static void set_addr(struct uh_addr *addr, void *src)
 516 {
 517         struct sockaddr_in *sin = src;
 518         struct sockaddr_in6 *sin6 = src;
 519
 520         addr->family = sin->sin_family;
 521         if (addr->family == AF_INET) {
 522                 addr->port = ntohs(sin->sin_port);
 523                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 524         } else {
 525                 addr->port = ntohs(sin6->sin6_port);
 526                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 527         }
 528 }
 529
 530 bool uh_accept_client(int fd, bool tls)
 531 {
 532         static struct client *next_client;
 533         struct client *cl;
 534         unsigned int sl;
 535         int sfd;
 536         static int client_id = 0;
 537         struct sockaddr_in6 addr;
 538
 539         if (!next_client)
 540                 next_client = calloc(1, sizeof(*next_client));
 541
 542         cl = next_client;
 543
 544         sl = sizeof(addr);
 545         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 546         if (sfd < 0)
 547                 return false;
 548
 549         set_addr(&cl->peer_addr, &addr);
 550         sl = sizeof(addr);
 551         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 552         set_addr(&cl->srv_addr, &addr);
 553
 554         cl->us = &cl->sfd.stream;
 555         if (tls) {
 556                 uh_tls_client_attach(cl);
 557         } else {
 558                 cl->us->notify_read = client_ustream_read_cb;
 559                 cl->us->notify_write = client_ustream_write_cb;
 560                 cl->us->notify_state = client_notify_state;
 561         }
 562
 563         cl->us->string_data = true;
 564         ustream_fd_init(&cl->sfd, sfd);
 565
 566         uh_poll_connection(cl);
 567         list_add_tail(&cl->list, &clients);
 568
 569         next_client = NULL;
 570         n_clients++;
 571         cl->id = client_id++;
 572         cl->tls = tls;
 573
 574         return true;
 575 }
 576
 577 void uh_close_fds(void)
 578 {
 579         struct client *cl;
 580
 581         uloop_done();
 582         uh_close_listen_fds();
 583         list_for_each_entry(cl, &clients, list) {
 584                 close(cl->sfd.fd.fd);
 585                 if (cl->dispatch.close_fds)
 586                         cl->dispatch.close_fds(cl);
 587         }
 588 }