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 void client_poll_post_data(struct client *cl)
 253 {
 254         struct dispatch *d = &cl->dispatch;
 255         struct http_request *r = &cl->request;
 256         char *buf;
 257         int len;
 258
 259         if (cl->state == CLIENT_STATE_DONE)
 260                 return;
 261
 262         while (1) {
 263                 char *sep;
 264                 int offset = 0;
 265                 int cur_len;
 266
 267                 buf = ustream_get_read_buf(cl->us, &len);
 268                 if (!buf || !len)
 269                         break;
 270
 271                 if (!d->data_send)
 272                         return;
 273
 274                 cur_len = min(r->content_length, len);
 275                 if (cur_len) {
 276                         if (d->data_blocked)
 277                                 break;
 278
 279                         if (d->data_send)
 280                                 cur_len = d->data_send(cl, buf, cur_len);
 281
 282                         r->content_length -= cur_len;
 283                         ustream_consume(cl->us, cur_len);
 284                         continue;
 285                 }
 286
 287                 if (!r->transfer_chunked)
 288                         break;
 289
 290                 if (r->transfer_chunked > 1)
 291                         offset = 2;
 292
 293                 sep = strstr(buf + offset, "\r\n");
 294                 if (!sep)
 295                         break;
 296
 297                 *sep = 0;
 298
 299                 r->content_length = strtoul(buf + offset, &sep, 16);
 300                 r->transfer_chunked++;
 301                 ustream_consume(cl->us, sep + 2 - buf);
 302
 303                 /* invalid chunk length */
 304                 if (sep && *sep) {
 305                         r->content_length = 0;
 306                         r->transfer_chunked = 0;
 307                         break;
 308                 }
 309
 310                 /* empty chunk == eof */
 311                 if (!r->content_length) {
 312                         r->transfer_chunked = false;
 313                         break;
 314                 }
 315         }
 316
 317         buf = ustream_get_read_buf(cl->us, &len);
 318         if (!r->content_length && !r->transfer_chunked &&
 319                 cl->state != CLIENT_STATE_DONE) {
 320                 if (cl->dispatch.data_done)
 321                         cl->dispatch.data_done(cl);
 322
 323                 cl->state = CLIENT_STATE_DONE;
 324         }
 325 }
 326
 327 static bool client_data_cb(struct client *cl, char *buf, int len)
 328 {
 329         client_poll_post_data(cl);
 330         return false;
 331 }
 332
 333 static bool client_header_cb(struct client *cl, char *buf, int len)
 334 {
 335         char *newline;
 336         int line_len;
 337
 338         newline = strstr(buf, "\r\n");
 339         if (!newline)
 340                 return false;
 341
 342         *newline = 0;
 343         client_parse_header(cl, buf);
 344         line_len = newline + 2 - buf;
 345         ustream_consume(cl->us, line_len);
 346         if (cl->state == CLIENT_STATE_DATA)
 347                 return client_data_cb(cl, newline + 2, len - line_len);
 348
 349         return true;
 350 }
 351
 352 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 353 static read_cb_t read_cbs[] = {
 354         [CLIENT_STATE_INIT] = client_init_cb,
 355         [CLIENT_STATE_HEADER] = client_header_cb,
 356         [CLIENT_STATE_DATA] = client_data_cb,
 357 };
 358
 359 static void client_read_cb(struct client *cl)
 360 {
 361         struct ustream *us = cl->us;
 362         char *str;
 363         int len;
 364
 365         do {
 366                 str = ustream_get_read_buf(us, &len);
 367                 if (!str || !len)
 368                         break;
 369
 370                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 371                         break;
 372
 373                 if (!read_cbs[cl->state](cl, str, len)) {
 374                         if (len == us->r.buffer_len &&
 375                             cl->state != CLIENT_STATE_DATA)
 376                                 uh_header_error(cl, 413, "Request Entity Too Large");
 377                         break;
 378                 }
 379         } while(1);
 380 }
 381
 382 static void client_close(struct client *cl)
 383 {
 384         n_clients--;
 385         uh_dispatch_done(cl);
 386         uloop_timeout_cancel(&cl->timeout);
 387         ustream_free(&cl->sfd.stream);
 388         close(cl->sfd.fd.fd);
 389         list_del(&cl->list);
 390         blob_buf_free(&cl->hdr);
 391         free(cl);
 392
 393         uh_unblock_listeners();
 394 }
 395
 396 static void client_ustream_read_cb(struct ustream *s, int bytes)
 397 {
 398         struct client *cl = container_of(s, struct client, sfd);
 399
 400         client_read_cb(cl);
 401 }
 402
 403 static void client_ustream_write_cb(struct ustream *s, int bytes)
 404 {
 405         struct client *cl = container_of(s, struct client, sfd);
 406
 407         if (cl->dispatch.write_cb)
 408                 cl->dispatch.write_cb(cl);
 409 }
 410
 411 static void client_notify_state(struct ustream *s)
 412 {
 413         struct client *cl = container_of(s, struct client, sfd);
 414
 415         if (!s->write_error) {
 416                 if (cl->state == CLIENT_STATE_DATA)
 417                         return;
 418
 419                 if (!s->eof || s->w.data_bytes)
 420                         return;
 421         }
 422
 423         return client_close(cl);
 424 }
 425
 426 static void set_addr(struct uh_addr *addr, void *src)
 427 {
 428         struct sockaddr_in *sin = src;
 429         struct sockaddr_in6 *sin6 = src;
 430
 431         addr->family = sin->sin_family;
 432         if (addr->family == AF_INET) {
 433                 addr->port = ntohs(sin->sin_port);
 434                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 435         } else {
 436                 addr->port = ntohs(sin6->sin6_port);
 437                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 438         }
 439 }
 440
 441 void uh_accept_client(int fd)
 442 {
 443         static struct client *next_client;
 444         struct client *cl;
 445         unsigned int sl;
 446         int sfd;
 447         static int client_id = 0;
 448         struct sockaddr_in6 addr;
 449
 450         if (!next_client)
 451                 next_client = calloc(1, sizeof(*next_client));
 452
 453         cl = next_client;
 454
 455         sl = sizeof(addr);
 456         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 457         if (sfd < 0)
 458                 return;
 459
 460         set_addr(&cl->peer_addr, &addr);
 461         sl = sizeof(addr);
 462         getsockname(fd, (struct sockaddr *) &addr, &sl);
 463         set_addr(&cl->srv_addr, &addr);
 464         cl->us = &cl->sfd.stream;
 465         cl->us->string_data = true;
 466         cl->us->notify_read = client_ustream_read_cb;
 467         cl->us->notify_write = client_ustream_write_cb;
 468         cl->us->notify_state = client_notify_state;
 469         ustream_fd_init(&cl->sfd, sfd);
 470
 471         cl->timeout.cb = client_timeout;
 472         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 473
 474         list_add_tail(&cl->list, &clients);
 475
 476         next_client = NULL;
 477         n_clients++;
 478         cl->id = client_id++;
 479 }
 480
 481 void uh_close_fds(void)
 482 {
 483         struct client *cl;
 484
 485         uloop_done();
 486         uh_close_listen_fds();
 487         list_for_each_entry(cl, &clients, list) {
 488                 close(cl->sfd.fd.fd);
 489                 if (cl->dispatch.close_fds)
 490                         cl->dispatch.close_fds(cl);
 491         }
 492 }