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                 char *sep;
 265
 266                 r->content_length -= cur_len;
 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                         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                 sep = strstr(buf, "\r\n");
 282                 if (!sep)
 283                         break;
 284
 285                 *sep = 0;
 286                 cur_len = sep + 2 - buf;
 287
 288                 r->content_length = strtoul(buf, &sep, 16);
 289
 290                 /* invalid chunk length */
 291                 if (sep && *sep)
 292                         return false;
 293
 294                 /* empty chunk == eof */
 295                 if (!r->content_length) {
 296                         r->transfer_chunked = false;
 297                         continue;
 298                 }
 299         }
 300
 301         ustream_consume(cl->us, consumed);
 302         return r->content_length || r->transfer_chunked;
 303 }
 304
 305 static bool client_header_cb(struct client *cl, char *buf, int len)
 306 {
 307         char *newline;
 308         int line_len;
 309
 310         newline = strstr(buf, "\r\n");
 311         if (!newline)
 312                 return false;
 313
 314         *newline = 0;
 315         client_parse_header(cl, buf);
 316         line_len = newline + 2 - buf;
 317         ustream_consume(cl->us, line_len);
 318         if (cl->state == CLIENT_STATE_DATA)
 319                 return client_data_cb(cl, newline + 2, len - line_len);
 320
 321         return true;
 322 }
 323
 324 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 325 static read_cb_t read_cbs[] = {
 326         [CLIENT_STATE_INIT] = client_init_cb,
 327         [CLIENT_STATE_HEADER] = client_header_cb,
 328         [CLIENT_STATE_DATA] = client_data_cb,
 329 };
 330
 331 static void client_read_cb(struct client *cl)
 332 {
 333         struct ustream *us = cl->us;
 334         char *str;
 335         int len;
 336
 337         do {
 338                 str = ustream_get_read_buf(us, &len);
 339                 if (!str || !len)
 340                         break;
 341
 342                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 343                         break;
 344
 345                 if (!read_cbs[cl->state](cl, str, len)) {
 346                         if (len == us->r.buffer_len)
 347                                 uh_header_error(cl, 413, "Request Entity Too Large");
 348                         if (cl->dispatch.data_done)
 349                                 cl->dispatch.data_done(cl);
 350                         break;
 351                 }
 352         } while(1);
 353 }
 354
 355 static void client_close(struct client *cl)
 356 {
 357         n_clients--;
 358         uh_dispatch_done(cl);
 359         uloop_timeout_cancel(&cl->timeout);
 360         ustream_free(&cl->sfd.stream);
 361         close(cl->sfd.fd.fd);
 362         list_del(&cl->list);
 363         blob_buf_free(&cl->hdr);
 364         free(cl);
 365
 366         uh_unblock_listeners();
 367 }
 368
 369 static void client_ustream_read_cb(struct ustream *s, int bytes)
 370 {
 371         struct client *cl = container_of(s, struct client, sfd);
 372
 373         client_read_cb(cl);
 374 }
 375
 376 static void client_ustream_write_cb(struct ustream *s, int bytes)
 377 {
 378         struct client *cl = container_of(s, struct client, sfd);
 379
 380         if (cl->dispatch.write_cb)
 381                 cl->dispatch.write_cb(cl);
 382 }
 383
 384 static void client_notify_state(struct ustream *s)
 385 {
 386         struct client *cl = container_of(s, struct client, sfd);
 387
 388         if (!s->write_error) {
 389                 if (cl->state == CLIENT_STATE_DATA)
 390                         return;
 391
 392                 if (!s->eof || s->w.data_bytes)
 393                         return;
 394         }
 395
 396         return client_close(cl);
 397 }
 398
 399 static void set_addr(struct uh_addr *addr, void *src)
 400 {
 401         struct sockaddr_in *sin = src;
 402         struct sockaddr_in6 *sin6 = src;
 403
 404         addr->family = sin->sin_family;
 405         if (addr->family == AF_INET) {
 406                 addr->port = ntohs(sin->sin_port);
 407                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 408         } else {
 409                 addr->port = ntohs(sin6->sin6_port);
 410                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 411         }
 412 }
 413
 414 void uh_accept_client(int fd)
 415 {
 416         static struct client *next_client;
 417         struct client *cl;
 418         unsigned int sl;
 419         int sfd;
 420         static int client_id = 0;
 421         struct sockaddr_in6 addr;
 422
 423         if (!next_client)
 424                 next_client = calloc(1, sizeof(*next_client));
 425
 426         cl = next_client;
 427
 428         sl = sizeof(addr);
 429         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 430         if (sfd < 0)
 431                 return;
 432
 433         set_addr(&cl->peer_addr, &addr);
 434         sl = sizeof(addr);
 435         getsockname(fd, (struct sockaddr *) &addr, &sl);
 436         set_addr(&cl->srv_addr, &addr);
 437         cl->us = &cl->sfd.stream;
 438         cl->us->string_data = true;
 439         cl->us->notify_read = client_ustream_read_cb;
 440         cl->us->notify_write = client_ustream_write_cb;
 441         cl->us->notify_state = client_notify_state;
 442         ustream_fd_init(&cl->sfd, sfd);
 443
 444         cl->timeout.cb = client_timeout;
 445         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 446
 447         list_add_tail(&cl->list, &clients);
 448
 449         next_client = NULL;
 450         n_clients++;
 451         cl->id = client_id++;
 452 }
 453
 454 void uh_close_fds(void)
 455 {
 456         struct client *cl;
 457
 458         uloop_done();
 459         uh_close_listen_fds();
 460         list_for_each_entry(cl, &clients, list) {
 461                 close(cl->sfd.fd.fd);
 462                 if (cl->dispatch.close_fds)
 463                         cl->dispatch.close_fds(cl);
 464         }
 465 }