client.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19
  20 #include <libubox/blobmsg.h>
  21 #include <ctype.h>
  22
  23 #include "uhttpd.h"
  24
  25 static LIST_HEAD(clients);
  26
  27 int n_clients = 0;
  28 struct config conf = {};
  29
  30 const char * const http_versions[] = {
  31         [UH_HTTP_VER_0_9] = "HTTP/0.9",
  32         [UH_HTTP_VER_1_0] = "HTTP/1.0",
  33         [UH_HTTP_VER_1_1] = "HTTP/1.1",
  34 };
  35
  36 const char * const http_methods[] = {
  37         [UH_HTTP_MSG_GET] = "GET",
  38         [UH_HTTP_MSG_POST] = "POST",
  39         [UH_HTTP_MSG_HEAD] = "HEAD",
  40 };
  41
  42 void uh_http_header(struct client *cl, int code, const char *summary)
  43 {
  44         const char *enc = "Transfer-Encoding: chunked\r\n";
  45         const char *conn;
  46
  47         if (!uh_use_chunked(cl))
  48                 enc = "";
  49
  50         if (cl->request.version != UH_HTTP_VER_1_1)
  51                 conn = "Connection: close";
  52         else
  53                 conn = "Connection: keep-alive";
  54
  55         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  56                 http_versions[cl->request.version],
  57                 code, summary, conn, enc);
  58 }
  59
  60 static void uh_connection_close(struct client *cl)
  61 {
  62         cl->state = CLIENT_STATE_CLOSE;
  63         cl->us->eof = true;
  64         ustream_state_change(cl->us);
  65 }
  66
  67 static void uh_dispatch_done(struct client *cl)
  68 {
  69         if (cl->dispatch.free)
  70                 cl->dispatch.free(cl);
  71 }
  72
  73 void uh_request_done(struct client *cl)
  74 {
  75         uh_chunk_eof(cl);
  76         uh_dispatch_done(cl);
  77         cl->us->notify_write = NULL;
  78         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
  79
  80         if (cl->request.version != UH_HTTP_VER_1_1 || !conf.http_keepalive) {
  81                 uh_connection_close(cl);
  82                 return;
  83         }
  84
  85         cl->state = CLIENT_STATE_INIT;
  86         uloop_timeout_set(&cl->timeout, conf.http_keepalive * 1000);
  87 }
  88
  89 void __printf(4, 5)
  90 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
  91 {
  92         va_list arg;
  93
  94         uh_http_header(cl, code, summary);
  95         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
  96
  97         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
  98
  99         if (fmt) {
 100                 va_start(arg, fmt);
 101                 uh_chunk_vprintf(cl, fmt, arg);
 102                 va_end(arg);
 103         }
 104
 105         uh_request_done(cl);
 106 }
 107
 108 static void uh_header_error(struct client *cl, int code, const char *summary)
 109 {
 110         uh_client_error(cl, code, summary, NULL);
 111         uh_connection_close(cl);
 112 }
 113
 114 static void client_timeout(struct uloop_timeout *timeout)
 115 {
 116         struct client *cl = container_of(timeout, struct client, timeout);
 117
 118         cl->state = CLIENT_STATE_CLOSE;
 119         uh_connection_close(cl);
 120 }
 121
 122 static int find_idx(const char * const *list, int max, const char *str)
 123 {
 124         int i;
 125
 126         for (i = 0; i < max; i++)
 127                 if (!strcmp(list[i], str))
 128                         return i;
 129
 130         return -1;
 131 }
 132
 133 static int client_parse_request(struct client *cl, char *data)
 134 {
 135         struct http_request *req = &cl->request;
 136         char *type, *path, *version;
 137         int h_method, h_version;
 138
 139         type = strtok(data, " ");
 140         path = strtok(NULL, " ");
 141         version = strtok(NULL, " ");
 142         if (!type || !path || !version)
 143                 return CLIENT_STATE_DONE;
 144
 145         blobmsg_add_string(&cl->hdr, "URL", path);
 146
 147         memset(&cl->request, 0, sizeof(cl->request));
 148         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 149         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 150         if (h_method < 0 || h_version < 0) {
 151                 req->version = UH_HTTP_VER_1_0;
 152                 return CLIENT_STATE_DONE;
 153         }
 154
 155         req->method = h_method;
 156         req->version = h_version;
 157
 158         return CLIENT_STATE_HEADER;
 159 }
 160
 161 static bool client_init_cb(struct client *cl, char *buf, int len)
 162 {
 163         char *newline;
 164
 165         newline = strstr(buf, "\r\n");
 166         if (!newline)
 167                 return false;
 168
 169         *newline = 0;
 170         blob_buf_init(&cl->hdr, 0);
 171         cl->state = client_parse_request(cl, buf);
 172         ustream_consume(cl->us, newline + 2 - buf);
 173         if (cl->state == CLIENT_STATE_DONE)
 174                 uh_header_error(cl, 400, "Bad Request");
 175
 176         return true;
 177 }
 178
 179 static bool rfc1918_filter_check(struct client *cl)
 180 {
 181         if (!conf.rfc1918_filter)
 182                 return true;
 183
 184         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 185                 return true;
 186
 187         uh_client_error(cl, 403, "Forbidden",
 188                         "Rejected request from RFC1918 IP "
 189                         "to public server address");
 190         return false;
 191 }
 192
 193 static void client_header_complete(struct client *cl)
 194 {
 195         if (!rfc1918_filter_check(cl))
 196                 return;
 197
 198         if (cl->request.expect_cont)
 199                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 200
 201         uh_handle_request(cl);
 202 }
 203
 204 static void client_parse_header(struct client *cl, char *data)
 205 {
 206         struct http_request *r = &cl->request;
 207         char *err;
 208         char *name;
 209         char *val;
 210
 211         if (!*data) {
 212                 uloop_timeout_cancel(&cl->timeout);
 213                 cl->state = CLIENT_STATE_DATA;
 214                 client_header_complete(cl);
 215                 return;
 216         }
 217
 218         val = uh_split_header(data);
 219         if (!val) {
 220                 cl->state = CLIENT_STATE_DONE;
 221                 return;
 222         }
 223
 224         for (name = data; *name; name++)
 225                 if (isupper(*name))
 226                         *name = tolower(*name);
 227
 228         if (!strcmp(data, "expect")) {
 229                 if (!strcasecmp(val, "100-continue"))
 230                         r->expect_cont = true;
 231                 else {
 232                         uh_header_error(cl, 412, "Precondition Failed");
 233                         return;
 234                 }
 235         } else if (!strcmp(data, "content-length")) {
 236                 r->content_length = strtoul(val, &err, 0);
 237                 if (err && *err) {
 238                         uh_header_error(cl, 400, "Bad Request");
 239                         return;
 240                 }
 241         } else if (!strcmp(data, "transfer-encoding")) {
 242                 if (!strcmp(val, "chunked"))
 243                         r->transfer_chunked = true;
 244         }
 245
 246
 247         blobmsg_add_string(&cl->hdr, data, val);
 248
 249         cl->state = CLIENT_STATE_HEADER;
 250 }
 251
 252 static bool client_data_cb(struct client *cl, char *buf, int len)
 253 {
 254         struct dispatch *d = &cl->dispatch;
 255         struct http_request *r = &cl->request;
 256         int consumed = 0;
 257         int cur_len = 0;
 258
 259         if (!d->data_send)
 260                 return false;
 261
 262         while (len) {
 263                 int offset = 0;
 264                 char *sep;
 265
 266                 consumed += cur_len;
 267                 buf += cur_len;
 268                 len -= cur_len;
 269                 cur_len = min(r->content_length, len);
 270
 271                 if (cur_len) {
 272                         r->content_length -= cur_len;
 273                         if (d->data_send)
 274                                 d->data_send(cl, buf, cur_len);
 275                         continue;
 276                 }
 277
 278                 if (!r->transfer_chunked)
 279                         break;
 280
 281                 if (r->transfer_chunked > 1)
 282                         offset = 2;
 283
 284                 sep = strstr(buf + offset, "\r\n");
 285                 if (!sep)
 286                         break;
 287
 288                 *sep = 0;
 289                 cur_len = sep + 2 - buf;
 290
 291                 r->content_length = strtoul(buf + offset, &sep, 16);
 292                 r->transfer_chunked++;
 293
 294                 /* invalid chunk length */
 295                 if (sep && *sep)
 296                         goto abort;
 297
 298                 /* empty chunk == eof */
 299                 if (!r->content_length)
 300                         r->transfer_chunked = false;
 301
 302                 continue;
 303
 304 abort:
 305                 consumed = len;
 306                 r->content_length = 0;
 307                 r->transfer_chunked = 0;
 308                 break;
 309         }
 310
 311         ustream_consume(cl->us, consumed);
 312         if (!r->content_length && !r->transfer_chunked) {
 313                 if (cl->dispatch.data_done)
 314                         cl->dispatch.data_done(cl);
 315
 316                 cl->state = CLIENT_STATE_DONE;
 317         }
 318         return false;
 319 }
 320
 321 static bool client_header_cb(struct client *cl, char *buf, int len)
 322 {
 323         char *newline;
 324         int line_len;
 325
 326         newline = strstr(buf, "\r\n");
 327         if (!newline)
 328                 return false;
 329
 330         *newline = 0;
 331         client_parse_header(cl, buf);
 332         line_len = newline + 2 - buf;
 333         ustream_consume(cl->us, line_len);
 334         if (cl->state == CLIENT_STATE_DATA)
 335                 return client_data_cb(cl, newline + 2, len - line_len);
 336
 337         return true;
 338 }
 339
 340 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 341 static read_cb_t read_cbs[] = {
 342         [CLIENT_STATE_INIT] = client_init_cb,
 343         [CLIENT_STATE_HEADER] = client_header_cb,
 344         [CLIENT_STATE_DATA] = client_data_cb,
 345 };
 346
 347 static void client_read_cb(struct client *cl)
 348 {
 349         struct ustream *us = cl->us;
 350         char *str;
 351         int len;
 352
 353         do {
 354                 str = ustream_get_read_buf(us, &len);
 355                 if (!str || !len)
 356                         break;
 357
 358                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 359                         break;
 360
 361                 if (!read_cbs[cl->state](cl, str, len)) {
 362                         if (len == us->r.buffer_len &&
 363                             cl->state != CLIENT_STATE_DATA)
 364                                 uh_header_error(cl, 413, "Request Entity Too Large");
 365                         break;
 366                 }
 367         } while(1);
 368 }
 369
 370 static void client_close(struct client *cl)
 371 {
 372         n_clients--;
 373         uh_dispatch_done(cl);
 374         uloop_timeout_cancel(&cl->timeout);
 375         ustream_free(&cl->sfd.stream);
 376         close(cl->sfd.fd.fd);
 377         list_del(&cl->list);
 378         blob_buf_free(&cl->hdr);
 379         free(cl);
 380
 381         uh_unblock_listeners();
 382 }
 383
 384 static void client_ustream_read_cb(struct ustream *s, int bytes)
 385 {
 386         struct client *cl = container_of(s, struct client, sfd);
 387
 388         client_read_cb(cl);
 389 }
 390
 391 static void client_ustream_write_cb(struct ustream *s, int bytes)
 392 {
 393         struct client *cl = container_of(s, struct client, sfd);
 394
 395         if (cl->dispatch.write_cb)
 396                 cl->dispatch.write_cb(cl);
 397 }
 398
 399 static void client_notify_state(struct ustream *s)
 400 {
 401         struct client *cl = container_of(s, struct client, sfd);
 402
 403         if (!s->write_error) {
 404                 if (cl->state == CLIENT_STATE_DATA)
 405                         return;
 406
 407                 if (!s->eof || s->w.data_bytes)
 408                         return;
 409         }
 410
 411         return client_close(cl);
 412 }
 413
 414 static void set_addr(struct uh_addr *addr, void *src)
 415 {
 416         struct sockaddr_in *sin = src;
 417         struct sockaddr_in6 *sin6 = src;
 418
 419         addr->family = sin->sin_family;
 420         if (addr->family == AF_INET) {
 421                 addr->port = ntohs(sin->sin_port);
 422                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 423         } else {
 424                 addr->port = ntohs(sin6->sin6_port);
 425                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 426         }
 427 }
 428
 429 void uh_accept_client(int fd)
 430 {
 431         static struct client *next_client;
 432         struct client *cl;
 433         unsigned int sl;
 434         int sfd;
 435         static int client_id = 0;
 436         struct sockaddr_in6 addr;
 437
 438         if (!next_client)
 439                 next_client = calloc(1, sizeof(*next_client));
 440
 441         cl = next_client;
 442
 443         sl = sizeof(addr);
 444         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 445         if (sfd < 0)
 446                 return;
 447
 448         set_addr(&cl->peer_addr, &addr);
 449         sl = sizeof(addr);
 450         getsockname(fd, (struct sockaddr *) &addr, &sl);
 451         set_addr(&cl->srv_addr, &addr);
 452         cl->us = &cl->sfd.stream;
 453         cl->us->string_data = true;
 454         cl->us->notify_read = client_ustream_read_cb;
 455         cl->us->notify_write = client_ustream_write_cb;
 456         cl->us->notify_state = client_notify_state;
 457         ustream_fd_init(&cl->sfd, sfd);
 458
 459         cl->timeout.cb = client_timeout;
 460         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 461
 462         list_add_tail(&cl->list, &clients);
 463
 464         next_client = NULL;
 465         n_clients++;
 466         cl->id = client_id++;
 467 }
 468
 469 void uh_close_fds(void)
 470 {
 471         struct client *cl;
 472
 473         uloop_done();
 474         uh_close_listen_fds();
 475         list_for_each_entry(cl, &clients, list) {
 476                 close(cl->sfd.fd.fd);
 477                 if (cl->dispatch.close_fds)
 478                         cl->dispatch.close_fds(cl);
 479         }
 480 }