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         memset(&cl->request, 0, sizeof(cl->request));
 146         req->url = path;
 147
 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         blobmsg_add_string(&cl->hdr, "REQUEST", buf);
 172         ustream_consume(cl->us, newline + 2 - buf);
 173         cl->state = client_parse_request(cl, (char *) blobmsg_data(blob_data(cl->hdr.head)));
 174         if (cl->state == CLIENT_STATE_DONE)
 175                 uh_header_error(cl, 400, "Bad Request");
 176
 177         return true;
 178 }
 179
 180 static bool rfc1918_filter_check(struct client *cl)
 181 {
 182         if (!conf.rfc1918_filter)
 183                 return true;
 184
 185         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 186                 return true;
 187
 188         uh_client_error(cl, 403, "Forbidden",
 189                         "Rejected request from RFC1918 IP "
 190                         "to public server address");
 191         return false;
 192 }
 193
 194 static void client_header_complete(struct client *cl)
 195 {
 196         if (!rfc1918_filter_check(cl))
 197                 return;
 198
 199         if (cl->request.expect_cont)
 200                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 201
 202         uh_handle_request(cl);
 203 }
 204
 205 static void client_parse_header(struct client *cl, char *data)
 206 {
 207         struct http_request *r = &cl->request;
 208         char *err;
 209         char *name;
 210         char *val;
 211
 212         if (!*data) {
 213                 uloop_timeout_cancel(&cl->timeout);
 214                 cl->state = CLIENT_STATE_DATA;
 215                 client_header_complete(cl);
 216                 return;
 217         }
 218
 219         val = uh_split_header(data);
 220         if (!val) {
 221                 cl->state = CLIENT_STATE_DONE;
 222                 return;
 223         }
 224
 225         for (name = data; *name; name++)
 226                 if (isupper(*name))
 227                         *name = tolower(*name);
 228
 229         if (!strcmp(data, "expect")) {
 230                 if (!strcasecmp(val, "100-continue"))
 231                         r->expect_cont = true;
 232                 else {
 233                         uh_header_error(cl, 412, "Precondition Failed");
 234                         return;
 235                 }
 236         } else if (!strcmp(data, "content-length")) {
 237                 r->content_length = strtoul(val, &err, 0);
 238                 if (err && *err) {
 239                         uh_header_error(cl, 400, "Bad Request");
 240                         return;
 241                 }
 242         } else if (!strcmp(data, "transfer-encoding")) {
 243                 if (!strcmp(val, "chunked"))
 244                         r->transfer_chunked = true;
 245         }
 246
 247
 248         blobmsg_add_string(&cl->hdr, data, val);
 249
 250         cl->state = CLIENT_STATE_HEADER;
 251 }
 252
 253 static bool client_data_cb(struct client *cl, char *buf, int len)
 254 {
 255         struct dispatch *d = &cl->dispatch;
 256         struct http_request *r = &cl->request;
 257         int consumed = 0;
 258         int cur_len = 0;
 259
 260         if (!d->data_send)
 261                 return false;
 262
 263         while (len) {
 264                 int offset = 0;
 265                 char *sep;
 266
 267                 consumed += cur_len;
 268                 buf += cur_len;
 269                 len -= cur_len;
 270                 cur_len = min(r->content_length, len);
 271
 272                 if (cur_len) {
 273                         r->content_length -= cur_len;
 274                         if (d->data_send)
 275                                 d->data_send(cl, buf, cur_len);
 276                         continue;
 277                 }
 278
 279                 if (!r->transfer_chunked)
 280                         break;
 281
 282                 if (r->transfer_chunked > 1)
 283                         offset = 2;
 284
 285                 sep = strstr(buf + offset, "\r\n");
 286                 if (!sep)
 287                         break;
 288
 289                 *sep = 0;
 290                 cur_len = sep + 2 - buf;
 291
 292                 r->content_length = strtoul(buf + offset, &sep, 16);
 293                 r->transfer_chunked++;
 294
 295                 /* invalid chunk length */
 296                 if (sep && *sep)
 297                         goto abort;
 298
 299                 /* empty chunk == eof */
 300                 if (!r->content_length)
 301                         r->transfer_chunked = false;
 302
 303                 continue;
 304
 305 abort:
 306                 consumed = len;
 307                 r->content_length = 0;
 308                 r->transfer_chunked = 0;
 309                 break;
 310         }
 311
 312         ustream_consume(cl->us, consumed);
 313         if (!r->content_length && !r->transfer_chunked) {
 314                 if (cl->dispatch.data_done)
 315                         cl->dispatch.data_done(cl);
 316
 317                 cl->state = CLIENT_STATE_DONE;
 318         }
 319         return false;
 320 }
 321
 322 static bool client_header_cb(struct client *cl, char *buf, int len)
 323 {
 324         char *newline;
 325         int line_len;
 326
 327         newline = strstr(buf, "\r\n");
 328         if (!newline)
 329                 return false;
 330
 331         *newline = 0;
 332         client_parse_header(cl, buf);
 333         line_len = newline + 2 - buf;
 334         ustream_consume(cl->us, line_len);
 335         if (cl->state == CLIENT_STATE_DATA)
 336                 return client_data_cb(cl, newline + 2, len - line_len);
 337
 338         return true;
 339 }
 340
 341 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 342 static read_cb_t read_cbs[] = {
 343         [CLIENT_STATE_INIT] = client_init_cb,
 344         [CLIENT_STATE_HEADER] = client_header_cb,
 345         [CLIENT_STATE_DATA] = client_data_cb,
 346 };
 347
 348 static void client_read_cb(struct client *cl)
 349 {
 350         struct ustream *us = cl->us;
 351         char *str;
 352         int len;
 353
 354         do {
 355                 str = ustream_get_read_buf(us, &len);
 356                 if (!str || !len)
 357                         break;
 358
 359                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 360                         break;
 361
 362                 if (!read_cbs[cl->state](cl, str, len)) {
 363                         if (len == us->r.buffer_len &&
 364                             cl->state != CLIENT_STATE_DATA)
 365                                 uh_header_error(cl, 413, "Request Entity Too Large");
 366                         break;
 367                 }
 368         } while(1);
 369 }
 370
 371 static void client_close(struct client *cl)
 372 {
 373         n_clients--;
 374         uh_dispatch_done(cl);
 375         uloop_timeout_cancel(&cl->timeout);
 376         ustream_free(&cl->sfd.stream);
 377         close(cl->sfd.fd.fd);
 378         list_del(&cl->list);
 379         blob_buf_free(&cl->hdr);
 380         free(cl);
 381
 382         uh_unblock_listeners();
 383 }
 384
 385 static void client_ustream_read_cb(struct ustream *s, int bytes)
 386 {
 387         struct client *cl = container_of(s, struct client, sfd);
 388
 389         client_read_cb(cl);
 390 }
 391
 392 static void client_ustream_write_cb(struct ustream *s, int bytes)
 393 {
 394         struct client *cl = container_of(s, struct client, sfd);
 395
 396         if (cl->dispatch.write_cb)
 397                 cl->dispatch.write_cb(cl);
 398 }
 399
 400 static void client_notify_state(struct ustream *s)
 401 {
 402         struct client *cl = container_of(s, struct client, sfd);
 403
 404         if (!s->write_error) {
 405                 if (cl->state == CLIENT_STATE_DATA)
 406                         return;
 407
 408                 if (!s->eof || s->w.data_bytes)
 409                         return;
 410         }
 411
 412         return client_close(cl);
 413 }
 414
 415 static void set_addr(struct uh_addr *addr, void *src)
 416 {
 417         struct sockaddr_in *sin = src;
 418         struct sockaddr_in6 *sin6 = src;
 419
 420         addr->family = sin->sin_family;
 421         if (addr->family == AF_INET) {
 422                 addr->port = ntohs(sin->sin_port);
 423                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 424         } else {
 425                 addr->port = ntohs(sin6->sin6_port);
 426                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 427         }
 428 }
 429
 430 void uh_accept_client(int fd)
 431 {
 432         static struct client *next_client;
 433         struct client *cl;
 434         unsigned int sl;
 435         int sfd;
 436         static int client_id = 0;
 437         struct sockaddr_in6 addr;
 438
 439         if (!next_client)
 440                 next_client = calloc(1, sizeof(*next_client));
 441
 442         cl = next_client;
 443
 444         sl = sizeof(addr);
 445         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 446         if (sfd < 0)
 447                 return;
 448
 449         set_addr(&cl->peer_addr, &addr);
 450         sl = sizeof(addr);
 451         getsockname(fd, (struct sockaddr *) &addr, &sl);
 452         set_addr(&cl->srv_addr, &addr);
 453         cl->us = &cl->sfd.stream;
 454         cl->us->string_data = true;
 455         cl->us->notify_read = client_ustream_read_cb;
 456         cl->us->notify_write = client_ustream_write_cb;
 457         cl->us->notify_state = client_notify_state;
 458         ustream_fd_init(&cl->sfd, sfd);
 459
 460         cl->timeout.cb = client_timeout;
 461         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 462
 463         list_add_tail(&cl->list, &clients);
 464
 465         next_client = NULL;
 466         n_clients++;
 467         cl->id = client_id++;
 468 }
 469
 470 void uh_close_fds(void)
 471 {
 472         struct client *cl;
 473
 474         uloop_done();
 475         uh_close_listen_fds();
 476         list_for_each_entry(cl, &clients, list) {
 477                 close(cl->sfd.fd.fd);
 478                 if (cl->dispatch.close_fds)
 479                         cl->dispatch.close_fds(cl);
 480         }
 481 }