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 #include "tls.h"
  25
  26 static LIST_HEAD(clients);
  27
  28 int n_clients = 0;
  29 struct config conf = {};
  30
  31 const char * const http_versions[] = {
  32         [UH_HTTP_VER_0_9] = "HTTP/0.9",
  33         [UH_HTTP_VER_1_0] = "HTTP/1.0",
  34         [UH_HTTP_VER_1_1] = "HTTP/1.1",
  35 };
  36
  37 const char * const http_methods[] = {
  38         [UH_HTTP_MSG_GET] = "GET",
  39         [UH_HTTP_MSG_POST] = "POST",
  40         [UH_HTTP_MSG_HEAD] = "HEAD",
  41 };
  42
  43 void uh_http_header(struct client *cl, int code, const char *summary)
  44 {
  45         const char *enc = "Transfer-Encoding: chunked\r\n";
  46         const char *conn;
  47
  48         if (!uh_use_chunked(cl))
  49                 enc = "";
  50
  51         if (cl->request.version != UH_HTTP_VER_1_1)
  52                 conn = "Connection: close";
  53         else
  54                 conn = "Connection: keep-alive";
  55
  56         ustream_printf(cl->us, "%s %03i %s\r\n%s\r\n%s",
  57                 http_versions[cl->request.version],
  58                 code, summary, conn, enc);
  59 }
  60
  61 static void uh_connection_close(struct client *cl)
  62 {
  63         cl->state = CLIENT_STATE_CLOSE;
  64         cl->us->eof = true;
  65         ustream_state_change(cl->us);
  66 }
  67
  68 static void uh_dispatch_done(struct client *cl)
  69 {
  70         if (cl->dispatch.free)
  71                 cl->dispatch.free(cl);
  72 }
  73
  74 void uh_request_done(struct client *cl)
  75 {
  76         uh_chunk_eof(cl);
  77         uh_dispatch_done(cl);
  78         cl->us->notify_write = NULL;
  79         memset(&cl->dispatch, 0, sizeof(cl->dispatch));
  80
  81         if (cl->request.version != UH_HTTP_VER_1_1 || !conf.http_keepalive) {
  82                 uh_connection_close(cl);
  83                 return;
  84         }
  85
  86         cl->state = CLIENT_STATE_INIT;
  87         uloop_timeout_set(&cl->timeout, conf.http_keepalive * 1000);
  88 }
  89
  90 void __printf(4, 5)
  91 uh_client_error(struct client *cl, int code, const char *summary, const char *fmt, ...)
  92 {
  93         va_list arg;
  94
  95         uh_http_header(cl, code, summary);
  96         ustream_printf(cl->us, "Content-Type: text/html\r\n\r\n");
  97
  98         uh_chunk_printf(cl, "<h1>%s</h1>", summary);
  99
 100         if (fmt) {
 101                 va_start(arg, fmt);
 102                 uh_chunk_vprintf(cl, fmt, arg);
 103                 va_end(arg);
 104         }
 105
 106         uh_request_done(cl);
 107 }
 108
 109 static void uh_header_error(struct client *cl, int code, const char *summary)
 110 {
 111         uh_client_error(cl, code, summary, NULL);
 112         uh_connection_close(cl);
 113 }
 114
 115 static void client_timeout(struct uloop_timeout *timeout)
 116 {
 117         struct client *cl = container_of(timeout, struct client, timeout);
 118
 119         cl->state = CLIENT_STATE_CLOSE;
 120         uh_connection_close(cl);
 121 }
 122
 123 static int find_idx(const char * const *list, int max, const char *str)
 124 {
 125         int i;
 126
 127         for (i = 0; i < max; i++)
 128                 if (!strcmp(list[i], str))
 129                         return i;
 130
 131         return -1;
 132 }
 133
 134 static int client_parse_request(struct client *cl, char *data)
 135 {
 136         struct http_request *req = &cl->request;
 137         char *type, *path, *version;
 138         int h_method, h_version;
 139
 140         type = strtok(data, " ");
 141         path = strtok(NULL, " ");
 142         version = strtok(NULL, " ");
 143         if (!type || !path || !version)
 144                 return CLIENT_STATE_DONE;
 145
 146         blobmsg_add_string(&cl->hdr, "URL", path);
 147
 148         memset(&cl->request, 0, sizeof(cl->request));
 149         h_method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 150         h_version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 151         if (h_method < 0 || h_version < 0) {
 152                 req->version = UH_HTTP_VER_1_0;
 153                 return CLIENT_STATE_DONE;
 154         }
 155
 156         req->method = h_method;
 157         req->version = h_version;
 158
 159         return CLIENT_STATE_HEADER;
 160 }
 161
 162 static bool client_init_cb(struct client *cl, char *buf, int len)
 163 {
 164         char *newline;
 165
 166         newline = strstr(buf, "\r\n");
 167         if (!newline)
 168                 return false;
 169
 170         *newline = 0;
 171         blob_buf_init(&cl->hdr, 0);
 172         cl->state = client_parse_request(cl, buf);
 173         ustream_consume(cl->us, newline + 2 - buf);
 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 void client_poll_post_data(struct client *cl)
 254 {
 255         struct dispatch *d = &cl->dispatch;
 256         struct http_request *r = &cl->request;
 257         char *buf;
 258         int len;
 259
 260         if (cl->state == CLIENT_STATE_DONE)
 261                 return;
 262
 263         while (1) {
 264                 char *sep;
 265                 int offset = 0;
 266                 int cur_len;
 267
 268                 buf = ustream_get_read_buf(cl->us, &len);
 269                 if (!buf || !len)
 270                         break;
 271
 272                 if (!d->data_send)
 273                         return;
 274
 275                 cur_len = min(r->content_length, len);
 276                 if (cur_len) {
 277                         if (d->data_blocked)
 278                                 break;
 279
 280                         if (d->data_send)
 281                                 cur_len = d->data_send(cl, buf, cur_len);
 282
 283                         r->content_length -= cur_len;
 284                         ustream_consume(cl->us, cur_len);
 285                         continue;
 286                 }
 287
 288                 if (!r->transfer_chunked)
 289                         break;
 290
 291                 if (r->transfer_chunked > 1)
 292                         offset = 2;
 293
 294                 sep = strstr(buf + offset, "\r\n");
 295                 if (!sep)
 296                         break;
 297
 298                 *sep = 0;
 299
 300                 r->content_length = strtoul(buf + offset, &sep, 16);
 301                 r->transfer_chunked++;
 302                 ustream_consume(cl->us, sep + 2 - buf);
 303
 304                 /* invalid chunk length */
 305                 if (sep && *sep) {
 306                         r->content_length = 0;
 307                         r->transfer_chunked = 0;
 308                         break;
 309                 }
 310
 311                 /* empty chunk == eof */
 312                 if (!r->content_length) {
 313                         r->transfer_chunked = false;
 314                         break;
 315                 }
 316         }
 317
 318         buf = ustream_get_read_buf(cl->us, &len);
 319         if (!r->content_length && !r->transfer_chunked &&
 320                 cl->state != CLIENT_STATE_DONE) {
 321                 if (cl->dispatch.data_done)
 322                         cl->dispatch.data_done(cl);
 323
 324                 cl->state = CLIENT_STATE_DONE;
 325         }
 326 }
 327
 328 static bool client_data_cb(struct client *cl, char *buf, int len)
 329 {
 330         client_poll_post_data(cl);
 331         return false;
 332 }
 333
 334 static bool client_header_cb(struct client *cl, char *buf, int len)
 335 {
 336         char *newline;
 337         int line_len;
 338
 339         newline = strstr(buf, "\r\n");
 340         if (!newline)
 341                 return false;
 342
 343         *newline = 0;
 344         client_parse_header(cl, buf);
 345         line_len = newline + 2 - buf;
 346         ustream_consume(cl->us, line_len);
 347         if (cl->state == CLIENT_STATE_DATA)
 348                 return client_data_cb(cl, newline + 2, len - line_len);
 349
 350         return true;
 351 }
 352
 353 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 354 static read_cb_t read_cbs[] = {
 355         [CLIENT_STATE_INIT] = client_init_cb,
 356         [CLIENT_STATE_HEADER] = client_header_cb,
 357         [CLIENT_STATE_DATA] = client_data_cb,
 358 };
 359
 360 void uh_client_read_cb(struct client *cl)
 361 {
 362         struct ustream *us = cl->us;
 363         char *str;
 364         int len;
 365
 366         do {
 367                 str = ustream_get_read_buf(us, &len);
 368                 if (!str || !len)
 369                         break;
 370
 371                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 372                         break;
 373
 374                 if (!read_cbs[cl->state](cl, str, len)) {
 375                         if (len == us->r.buffer_len &&
 376                             cl->state != CLIENT_STATE_DATA)
 377                                 uh_header_error(cl, 413, "Request Entity Too Large");
 378                         break;
 379                 }
 380         } while(1);
 381 }
 382
 383 static void client_close(struct client *cl)
 384 {
 385         n_clients--;
 386         uh_dispatch_done(cl);
 387         uloop_timeout_cancel(&cl->timeout);
 388         if (cl->tls)
 389                 uh_tls_client_detach(cl);
 390         ustream_free(&cl->sfd.stream);
 391         close(cl->sfd.fd.fd);
 392         list_del(&cl->list);
 393         blob_buf_free(&cl->hdr);
 394         free(cl);
 395
 396         uh_unblock_listeners();
 397 }
 398
 399 void uh_client_notify_state(struct client *cl)
 400 {
 401         struct ustream *s = cl->us;
 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 client_ustream_read_cb(struct ustream *s, int bytes)
 415 {
 416         struct client *cl = container_of(s, struct client, sfd);
 417
 418         uh_client_read_cb(cl);
 419 }
 420
 421 static void client_ustream_write_cb(struct ustream *s, int bytes)
 422 {
 423         struct client *cl = container_of(s, struct client, sfd);
 424
 425         if (cl->dispatch.write_cb)
 426                 cl->dispatch.write_cb(cl);
 427 }
 428
 429 static void client_notify_state(struct ustream *s)
 430 {
 431         struct client *cl = container_of(s, struct client, sfd);
 432
 433         uh_client_notify_state(cl);
 434 }
 435
 436 static void set_addr(struct uh_addr *addr, void *src)
 437 {
 438         struct sockaddr_in *sin = src;
 439         struct sockaddr_in6 *sin6 = src;
 440
 441         addr->family = sin->sin_family;
 442         if (addr->family == AF_INET) {
 443                 addr->port = ntohs(sin->sin_port);
 444                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 445         } else {
 446                 addr->port = ntohs(sin6->sin6_port);
 447                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 448         }
 449 }
 450
 451 bool uh_accept_client(int fd, bool tls)
 452 {
 453         static struct client *next_client;
 454         struct client *cl;
 455         unsigned int sl;
 456         int sfd;
 457         static int client_id = 0;
 458         struct sockaddr_in6 addr;
 459
 460         if (!next_client)
 461                 next_client = calloc(1, sizeof(*next_client));
 462
 463         cl = next_client;
 464
 465         sl = sizeof(addr);
 466         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 467         if (sfd < 0)
 468                 return false;
 469
 470         set_addr(&cl->peer_addr, &addr);
 471         sl = sizeof(addr);
 472         getsockname(sfd, (struct sockaddr *) &addr, &sl);
 473         set_addr(&cl->srv_addr, &addr);
 474
 475         cl->us = &cl->sfd.stream;
 476         if (tls) {
 477                 uh_tls_client_attach(cl);
 478         } else {
 479                 cl->us->notify_read = client_ustream_read_cb;
 480                 cl->us->notify_write = client_ustream_write_cb;
 481                 cl->us->notify_state = client_notify_state;
 482         }
 483
 484         cl->us->string_data = true;
 485         ustream_fd_init(&cl->sfd, sfd);
 486
 487         cl->timeout.cb = client_timeout;
 488         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 489
 490         list_add_tail(&cl->list, &clients);
 491
 492         next_client = NULL;
 493         n_clients++;
 494         cl->id = client_id++;
 495
 496         return true;
 497 }
 498
 499 void uh_close_fds(void)
 500 {
 501         struct client *cl;
 502
 503         uloop_done();
 504         uh_close_listen_fds();
 505         list_for_each_entry(cl, &clients, list) {
 506                 close(cl->sfd.fd.fd);
 507                 if (cl->dispatch.close_fds)
 508                         cl->dispatch.close_fds(cl);
 509         }
 510 }