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         cl->http_code = code;
  52
  53         if (!uh_use_chunked(cl))
  54                 enc = "";
  55
  56         if (r->connection_close)
  57                 conn = "Connection: close";
  58         else
  59                 conn = "Connection: Keep-Alive";
  60
  61         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  62                 http_versions[cl->request.version],
  63                 code, summary, conn, enc);
  64
  65         if (!r->connection_close)
  66                 ustream_printf(cl->us, "Keep-Alive: timeout=%d\r\n", conf.http_keepalive);
  67 }
  68
  69 static void uh_connection_close(struct client *cl)
  70 {
  71         cl->state = CLIENT_STATE_CLOSE;
  72         cl->us->eof = true;
  73         ustream_state_change(cl->us);
  74 }
  75
  76 static void uh_dispatch_done(struct client *cl)
  77 {
  78         if (cl->dispatch.free)
  79                 cl->dispatch.free(cl);
  80         if (cl->dispatch.req_free)
  81                 cl->dispatch.req_free(cl);
  82 }
  83
  84 static void client_timeout(struct uloop_timeout *timeout)
  85 {
  86         struct client *cl = container_of(timeout, struct client, timeout);
  87
  88         cl->state = CLIENT_STATE_CLOSE;
  89         uh_connection_close(cl);
  90 }
  91
  92 static void uh_set_client_timeout(struct client *cl, int timeout)
  93 {
  94         cl->timeout.cb = client_timeout;
  95         uloop_timeout_set(&cl->timeout, timeout * 1000);
  96 }
  97
  98 static void uh_keepalive_poll_cb(struct uloop_timeout *timeout)
  99 {
 100         struct client *cl = container_of(timeout, struct client, timeout);
 101         int sec = cl->requests > 0 ? conf.http_keepalive : conf.network_timeout;
 102
 103         uh_set_client_timeout(cl, sec);
 104         cl->us->notify_read(cl->us, 0);
 105 }
 106
 107 static void uh_poll_connection(struct client *cl)
 108 {
 109         cl->timeout.cb = uh_keepalive_poll_cb;
 110         uloop_timeout_set(&cl->timeout, 1);
 111 }
 112
 113 void uh_request_done(struct client *cl)
 114 {
 115         uh_chunk_eof(cl);
 116         uh_dispatch_done(cl);
 117         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
 118
 119         if (!conf.http_keepalive || cl->request.connection_close)
 120                 return uh_connection_close(cl);
 121
 122         cl->state = CLIENT_STATE_INIT;
 123         cl->requests++;
 124         uh_poll_connection(cl);
 125 }
 126
 127 void __printf(4, 5)
 128 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
 129 {
 130         va_list arg;
 131
 132         uh_http_header(cl, code, summary);
 133         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
 134
 135         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
 136
 137         if (fmt) {
 138                 va_start(arg, fmt);
 139                 uh_chunk_vprintf(cl, fmt, arg);
 140                 va_end(arg);
 141         }
 142
 143         uh_request_done(cl);
 144 }
 145
 146 static void uh_header_error(struct client *cl, int code, const char *summary)
 147 {
 148         uh_client_error(cl, code, summary, NULL);
 149         uh_connection_close(cl);
 150 }
 151
 152 static int find_idx(const char * const *list, int max, const char *str)
 153 {
 154         int i;
 155
 156         for (i = 0; i < max; i++)
 157                 if (!strcmp(list[i], str))
 158                         return i;
 159
 160         return -1;
 161 }
 162
 163 static int client_parse_request(struct client *cl, char *data)
 164 {
 165         struct http_request *req = &cl->request;
 166         char *type, *path, *version;
 167         int h_method, h_version;
 168
 169         type = strtok(data, " ");
 170         path = strtok(NULL, " ");
 171         version = strtok(NULL, " ");
 172         if (!type || !path || !version)
 173                 return CLIENT_STATE_DONE;
 174
 175         blobmsg_add_string(&cl->hdr, "URL", path);
 176
 177         memset(&cl->request, 0, sizeof(cl->request));
 178         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 179         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 180         if (h_method < 0 || h_version < 0) {
 181                 req->version = UH_HTTP_VER_1_0;
 182                 return CLIENT_STATE_DONE;
 183         }
 184
 185         req->method = h_method;
 186         req->version = h_version;
 187         if (req->version < UH_HTTP_VER_1_1 || req->method == UH_HTTP_MSG_POST ||
 188             !conf.http_keepalive)
 189                 req->connection_close = true;
 190
 191         return CLIENT_STATE_HEADER;
 192 }
 193
 194 static bool client_init_cb(struct client *cl, char *buf, int len)
 195 {
 196         char *newline;
 197
 198         newline = strstr(buf, "\r\n");
 199         if (!newline)
 200                 return false;
 201
 202         if (newline == buf) {
 203                 ustream_consume(cl->us, 2);
 204                 return true;
 205         }
 206
 207         *newline = 0;
 208         blob_buf_init(&cl->hdr, 0);
 209         cl->state = client_parse_request(cl, buf);
 210         ustream_consume(cl->us, newline + 2 - buf);
 211         if (cl->state == CLIENT_STATE_DONE)
 212                 uh_header_error(cl, 400, "Bad Request");
 213
 214         return true;
 215 }
 216
 217 static bool rfc1918_filter_check(struct client *cl)
 218 {
 219         if (!conf.rfc1918_filter)
 220                 return true;
 221
 222         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 223                 return true;
 224
 225         uh_client_error(cl, 403, "Forbidden",
 226                         "Rejected request from RFC1918 IP "
 227                         "to public server address");
 228         return false;
 229 }
 230
 231 static void client_header_complete(struct client *cl)
 232 {
 233         struct http_request *r = &cl->request;
 234
 235         if (!rfc1918_filter_check(cl))
 236                 return;
 237
 238         if (r->expect_cont)
 239                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 240
 241         switch(r->ua) {
 242         case UH_UA_MSIE_OLD:
 243                 if (r->method != UH_HTTP_MSG_POST)
 244                         break;
 245
 246                 /* fall through */
 247         case UH_UA_SAFARI:
 248                 r->connection_close = true;
 249                 break;
 250         default:
 251                 break;
 252         }
 253
 254         uh_handle_request(cl);
 255 }
 256
 257 static void client_parse_header(struct client *cl, char *data)
 258 {
 259         struct http_request *r = &cl->request;
 260         char *err;
 261         char *name;
 262         char *val;
 263
 264         if (!*data) {
 265                 uloop_timeout_cancel(&cl->timeout);
 266                 cl->state = CLIENT_STATE_DATA;
 267                 client_header_complete(cl);
 268                 return;
 269         }
 270
 271         val = uh_split_header(data);
 272         if (!val) {
 273                 cl->state = CLIENT_STATE_DONE;
 274                 return;
 275         }
 276
 277         for (name = data; *name; name++)
 278                 if (isupper(*name))
 279                         *name = tolower(*name);
 280
 281         if (!strcmp(data, "expect")) {
 282                 if (!strcasecmp(val, "100-continue"))
 283                         r->expect_cont = true;
 284                 else {
 285                         uh_header_error(cl, 412, "Precondition Failed");
 286                         return;
 287                 }
 288         } else if (!strcmp(data, "content-length")) {
 289                 r->content_length = strtoul(val, &err, 0);
 290                 if (err && *err) {
 291                         uh_header_error(cl, 400, "Bad Request");
 292                         return;
 293                 }
 294         } else if (!strcmp(data, "transfer-encoding")) {
 295                 if (!strcmp(val, "chunked"))
 296                         r->transfer_chunked = true;
 297         } else if (!strcmp(data, "connection")) {
 298                 if (!strcasecmp(val, "close"))
 299                         r->connection_close = true;
 300         } else if (!strcmp(data, "user-agent")) {
 301                 char *str;
 302
 303                 if (strstr(val, "Opera"))
 304                         r->ua = UH_UA_OPERA;
 305                 else if ((str = strstr(val, "MSIE ")) != NULL) {
 306                         r->ua = UH_UA_MSIE_NEW;
 307                         if (str[5] && str[6] == '.') {
 308                                 switch (str[5]) {
 309                                 case '6':
 310                                         if (strstr(str, "SV1"))
 311                                                 break;
 312                                         /* fall through */
 313                                 case '5':
 314                                 case '4':
 315                                         r->ua = UH_UA_MSIE_OLD;
 316                                         break;
 317                                 }
 318                         }
 319                 }
 320                 else if (strstr(val, "Chrome/"))
 321                         r->ua = UH_UA_CHROME;
 322                 else if (strstr(val, "Safari/") && strstr(val, "Mac OS X"))
 323                         r->ua = UH_UA_SAFARI;
 324                 else if (strstr(val, "Gecko/"))
 325                         r->ua = UH_UA_GECKO;
 326                 else if (strstr(val, "Konqueror"))
 327                         r->ua = UH_UA_KONQUEROR;
 328         }
 329
 330
 331         blobmsg_add_string(&cl->hdr, data, val);
 332
 333         cl->state = CLIENT_STATE_HEADER;
 334 }
 335
 336 void client_poll_post_data(struct client *cl)
 337 {
 338         struct dispatch *d = &cl->dispatch;
 339         struct http_request *r = &cl->request;
 340         char *buf;
 341         int len;
 342
 343         if (cl->state == CLIENT_STATE_DONE)
 344                 return;
 345
 346         while (1) {
 347                 char *sep;
 348                 int offset = 0;
 349                 int cur_len;
 350
 351                 buf = ustream_get_read_buf(cl->us, &len);
 352                 if (!buf || !len)
 353                         break;
 354
 355                 if (!d->data_send)
 356                         return;
 357
 358                 cur_len = min(r->content_length, len);
 359                 if (cur_len) {
 360                         if (d->data_blocked)
 361                                 break;
 362
 363                         if (d->data_send)
 364                                 cur_len = d->data_send(cl, buf, cur_len);
 365
 366                         r->content_length -= cur_len;
 367                         ustream_consume(cl->us, cur_len);
 368                         continue;
 369                 }
 370
 371                 if (!r->transfer_chunked)
 372                         break;
 373
 374                 if (r->transfer_chunked > 1)
 375                         offset = 2;
 376
 377                 sep = strstr(buf + offset, "\r\n");
 378                 if (!sep)
 379                         break;
 380
 381                 *sep = 0;
 382
 383                 r->content_length = strtoul(buf + offset, &sep, 16);
 384                 r->transfer_chunked++;
 385                 ustream_consume(cl->us, sep + 2 - buf);
 386
 387                 /* invalid chunk length */
 388                 if (sep && *sep) {
 389                         r->content_length = 0;
 390                         r->transfer_chunked = 0;
 391                         break;
 392                 }
 393
 394                 /* empty chunk == eof */
 395                 if (!r->content_length) {
 396                         r->transfer_chunked = false;
 397                         break;
 398                 }
 399         }
 400
 401         buf = ustream_get_read_buf(cl->us, &len);
 402         if (!r->content_length && !r->transfer_chunked &&
 403                 cl->state != CLIENT_STATE_DONE) {
 404                 if (cl->dispatch.data_done)
 405                         cl->dispatch.data_done(cl);
 406
 407                 cl->state = CLIENT_STATE_DONE;
 408         }
 409 }
 410
 411 static bool client_data_cb(struct client *cl, char *buf, int len)
 412 {
 413         client_poll_post_data(cl);
 414         return false;
 415 }
 416
 417 static bool client_header_cb(struct client *cl, char *buf, int len)
 418 {
 419         char *newline;
 420         int line_len;
 421
 422         newline = strstr(buf, "\r\n");
 423         if (!newline)
 424                 return false;
 425
 426         *newline = 0;
 427         client_parse_header(cl, buf);
 428         line_len = newline + 2 - buf;
 429         ustream_consume(cl->us, line_len);
 430         if (cl->state == CLIENT_STATE_DATA)
 431                 return client_data_cb(cl, newline + 2, len - line_len);
 432
 433         return true;
 434 }
 435
 436 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 437 static read_cb_t read_cbs[] = {
 438         [CLIENT_STATE_INIT] = client_init_cb,
 439         [CLIENT_STATE_HEADER] = client_header_cb,
 440         [CLIENT_STATE_DATA] = client_data_cb,
 441 };
 442
 443 void uh_client_read_cb(struct client *cl)
 444 {
 445         struct ustream *us = cl->us;
 446         char *str;
 447         int len;
 448
 449         client_done = false;
 450         do {
 451                 str = ustream_get_read_buf(us, &len);
 452                 if (!str || !len)
 453                         break;
 454
 455                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 456                         break;
 457
 458                 if (!read_cbs[cl->state](cl, str, len)) {
 459                         if (len == us->r.buffer_len &&
 460                             cl->state != CLIENT_STATE_DATA)
 461                                 uh_header_error(cl, 413, "Request Entity Too Large");
 462                         break;
 463                 }
 464         } while (!client_done);
 465 }
 466
 467 static void client_close(struct client *cl)
 468 {
 469         if (cl->refcount) {
 470                 cl->state = CLIENT_STATE_CLEANUP;
 471                 return;
 472         }
 473
 474         client_done = true;
 475         n_clients--;
 476         uh_dispatch_done(cl);
 477         uloop_timeout_cancel(&cl->timeout);
 478         if (cl->tls)
 479                 uh_tls_client_detach(cl);
 480         ustream_free(&cl->sfd.stream);
 481         close(cl->sfd.fd.fd);
 482         list_del(&cl->list);
 483         blob_buf_free(&cl->hdr);
 484         free(cl);
 485
 486         uh_unblock_listeners();
 487 }
 488
 489 void uh_client_notify_state(struct client *cl)
 490 {
 491         struct ustream *s = cl->us;
 492
 493         if (!s->write_error && cl->state != CLIENT_STATE_CLEANUP) {
 494                 if (cl->state == CLIENT_STATE_DATA)
 495                         return;
 496
 497                 if (!s->eof || s->w.data_bytes)
 498                         return;
 499         }
 500
 501         return client_close(cl);
 502 }
 503
 504 static void client_ustream_read_cb(struct ustream *s, int bytes)
 505 {
 506         struct client *cl = container_of(s, struct client, sfd.stream);
 507
 508         uh_client_read_cb(cl);
 509 }
 510
 511 static void client_ustream_write_cb(struct ustream *s, int bytes)
 512 {
 513         struct client *cl = container_of(s, struct client, sfd.stream);
 514
 515         if (cl->dispatch.write_cb)
 516                 cl->dispatch.write_cb(cl);
 517 }
 518
 519 static void client_notify_state(struct ustream *s)
 520 {
 521         struct client *cl = container_of(s, struct client, sfd.stream);
 522
 523         uh_client_notify_state(cl);
 524 }
 525
 526 static void set_addr(struct uh_addr *addr, void *src)
 527 {
 528         struct sockaddr_in *sin = src;
 529         struct sockaddr_in6 *sin6 = src;
 530
 531         addr->family = sin->sin_family;
 532         if (addr->family == AF_INET) {
 533                 addr->port = ntohs(sin->sin_port);
 534                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 535         } else {
 536                 addr->port = ntohs(sin6->sin6_port);
 537                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 538         }
 539 }
 540
 541 bool uh_accept_client(int fd, bool tls)
 542 {
 543         static struct client *next_client;
 544         struct client *cl;
 545         unsigned int sl;
 546         int sfd;
 547         static int client_id = 0;
 548         struct sockaddr_in6 addr;
 549
 550         if (!next_client)
 551                 next_client = calloc(1, sizeof(*next_client));
 552
 553         cl = next_client;
 554
 555         sl = sizeof(addr);
 556         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 557         if (sfd < 0)
 558                 return false;
 559
 560         set_addr(&cl->peer_addr, &addr);
 561         sl = sizeof(addr);
 562         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 563         set_addr(&cl->srv_addr, &addr);
 564
 565         cl->us = &cl->sfd.stream;
 566         if (tls) {
 567                 uh_tls_client_attach(cl);
 568         } else {
 569                 cl->us->notify_read = client_ustream_read_cb;
 570                 cl->us->notify_write = client_ustream_write_cb;
 571                 cl->us->notify_state = client_notify_state;
 572         }
 573
 574         cl->us->string_data = true;
 575         ustream_fd_init(&cl->sfd, sfd);
 576
 577         uh_poll_connection(cl);
 578         list_add_tail(&cl->list, &clients);
 579
 580         next_client = NULL;
 581         n_clients++;
 582         cl->id = client_id++;
 583         cl->tls = tls;
 584
 585         return true;
 586 }
 587
 588 void uh_close_fds(void)
 589 {
 590         struct client *cl;
 591
 592         uloop_done();
 593         uh_close_listen_fds();
 594         list_for_each_entry(cl, &clients, list) {
 595                 close(cl->sfd.fd.fd);
 596                 if (cl->dispatch.close_fds)
 597                         cl->dispatch.close_fds(cl);
 598         }
 599 }