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
 138         type = strtok(data, " ");
 139         path = strtok(NULL, " ");
 140         version = strtok(NULL, " ");
 141         if (!type || !path || !version)
 142                 return CLIENT_STATE_DONE;
 143
 144         memset(&cl->request, 0, sizeof(cl->request));
 145         req->url = path;
 146         req->method = find_idx(http_methods, ARRAY_SIZE(http_methods), type);
 147         if (req->method < 0)
 148                 return CLIENT_STATE_DONE;
 149
 150         req->version = find_idx(http_versions, ARRAY_SIZE(http_versions), version);
 151         if (cl->request.version < 0)
 152                 return CLIENT_STATE_DONE;
 153
 154         return CLIENT_STATE_HEADER;
 155 }
 156
 157 static bool client_init_cb(struct client *cl, char *buf, int len)
 158 {
 159         char *newline;
 160
 161         newline = strstr(buf, "\r\n");
 162         if (!newline)
 163                 return false;
 164
 165         *newline = 0;
 166         blob_buf_init(&cl->hdr, 0);
 167         blobmsg_add_string(&cl->hdr, "REQUEST", buf);
 168         ustream_consume(cl->us, newline + 2 - buf);
 169         cl->state = client_parse_request(cl, (char *) blobmsg_data(blob_data(cl->hdr.head)));
 170         if (cl->state == CLIENT_STATE_DONE)
 171                 uh_header_error(cl, 400, "Bad Request");
 172
 173         return true;
 174 }
 175
 176 static bool rfc1918_filter_check(struct client *cl)
 177 {
 178         if (!conf.rfc1918_filter)
 179                 return true;
 180
 181         if (!uh_addr_rfc1918(&cl->peer_addr) || uh_addr_rfc1918(&cl->srv_addr))
 182                 return true;
 183
 184         uh_client_error(cl, 403, "Forbidden",
 185                         "Rejected request from RFC1918 IP "
 186                         "to public server address");
 187         return false;
 188 }
 189
 190 static void client_header_complete(struct client *cl)
 191 {
 192         if (!rfc1918_filter_check(cl))
 193                 return;
 194
 195         if (cl->request.expect_cont)
 196                 ustream_printf(cl->us, "HTTP/1.1 100 Continue\r\n\r\n");
 197
 198         uh_handle_request(cl);
 199 }
 200
 201 static void client_parse_header(struct client *cl, char *data)
 202 {
 203         char *name;
 204         char *val;
 205
 206         if (!*data) {
 207                 uloop_timeout_cancel(&cl->timeout);
 208                 cl->state = CLIENT_STATE_DATA;
 209                 client_header_complete(cl);
 210                 return;
 211         }
 212
 213         val = uh_split_header(data);
 214         if (!val) {
 215                 cl->state = CLIENT_STATE_DONE;
 216                 return;
 217         }
 218
 219         for (name = data; *name; name++)
 220                 if (isupper(*name))
 221                         *name = tolower(*name);
 222
 223         if (!strcasecmp(data, "Expect") &&
 224             !strcasecmp(val, "100-continue"))
 225                 cl->request.expect_cont = true;
 226
 227         blobmsg_add_string(&cl->hdr, data, val);
 228
 229         cl->state = CLIENT_STATE_HEADER;
 230 }
 231
 232 static bool client_data_cb(struct client *cl, char *buf, int len)
 233 {
 234         return false;
 235 }
 236
 237 static bool client_header_cb(struct client *cl, char *buf, int len)
 238 {
 239         char *newline;
 240         int line_len;
 241
 242         newline = strstr(buf, "\r\n");
 243         if (!newline)
 244                 return false;
 245
 246         *newline = 0;
 247         client_parse_header(cl, buf);
 248         line_len = newline + 2 - buf;
 249         ustream_consume(cl->us, line_len);
 250         if (cl->state == CLIENT_STATE_DATA)
 251                 client_data_cb(cl, newline + 2, len - line_len);
 252
 253         return true;
 254 }
 255
 256 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 257 static read_cb_t read_cbs[] = {
 258         [CLIENT_STATE_INIT] = client_init_cb,
 259         [CLIENT_STATE_HEADER] = client_header_cb,
 260         [CLIENT_STATE_DATA] = client_data_cb,
 261 };
 262
 263 static void client_read_cb(struct client *cl)
 264 {
 265         struct ustream *us = cl->us;
 266         char *str;
 267         int len;
 268
 269         do {
 270                 str = ustream_get_read_buf(us, &len);
 271                 if (!str)
 272                         break;
 273
 274                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 275                         break;
 276
 277                 if (!read_cbs[cl->state](cl, str, len)) {
 278                         if (len == us->r.buffer_len)
 279                                 uh_header_error(cl, 413, "Request Entity Too Large");
 280                         break;
 281                 }
 282         } while(1);
 283 }
 284
 285 static void client_close(struct client *cl)
 286 {
 287         uh_dispatch_done(cl);
 288         uloop_timeout_cancel(&cl->timeout);
 289         ustream_free(&cl->sfd.stream);
 290         close(cl->sfd.fd.fd);
 291         list_del(&cl->list);
 292         blob_buf_free(&cl->hdr);
 293         free(cl);
 294
 295         uh_unblock_listeners();
 296 }
 297
 298 static void client_ustream_read_cb(struct ustream *s, int bytes)
 299 {
 300         struct client *cl = container_of(s, struct client, sfd);
 301
 302         client_read_cb(cl);
 303 }
 304
 305 static void client_ustream_write_cb(struct ustream *s, int bytes)
 306 {
 307         struct client *cl = container_of(s, struct client, sfd);
 308
 309         if (cl->dispatch.write_cb)
 310                 cl->dispatch.write_cb(cl);
 311 }
 312
 313 static void client_notify_state(struct ustream *s)
 314 {
 315         struct client *cl = container_of(s, struct client, sfd);
 316
 317         if (!s->write_error) {
 318                 if (cl->state == CLIENT_STATE_DATA)
 319                         return;
 320
 321                 if (!s->eof || s->w.data_bytes)
 322                         return;
 323         }
 324
 325         return client_close(cl);
 326 }
 327
 328 static void set_addr(struct uh_addr *addr, void *src)
 329 {
 330         struct sockaddr_in *sin = src;
 331         struct sockaddr_in6 *sin6 = src;
 332
 333         addr->family = sin->sin_family;
 334         if (addr->family == AF_INET) {
 335                 addr->port = ntohs(sin->sin_port);
 336                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 337         } else {
 338                 addr->port = ntohs(sin6->sin6_port);
 339                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 340         }
 341 }
 342
 343 void uh_accept_client(int fd)
 344 {
 345         static struct client *next_client;
 346         struct client *cl;
 347         unsigned int sl;
 348         int sfd;
 349         static int client_id = 0;
 350         struct sockaddr_in6 addr;
 351
 352         if (!next_client)
 353                 next_client = calloc(1, sizeof(*next_client));
 354
 355         cl = next_client;
 356
 357         sl = sizeof(addr);
 358         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 359         if (sfd < 0)
 360                 return;
 361
 362         set_addr(&cl->peer_addr, &addr);
 363         sl = sizeof(addr);
 364         getsockname(fd, (struct sockaddr *) &addr, &sl);
 365         set_addr(&cl->srv_addr, &addr);
 366         cl->us = &cl->sfd.stream;
 367         cl->us->string_data = true;
 368         cl->us->notify_read = client_ustream_read_cb;
 369         cl->us->notify_write = client_ustream_write_cb;
 370         cl->us->notify_state = client_notify_state;
 371         ustream_fd_init(&cl->sfd, sfd);
 372
 373         cl->timeout.cb = client_timeout;
 374         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 375
 376         list_add_tail(&cl->list, &clients);
 377
 378         next_client = NULL;
 379         n_clients++;
 380         cl->id = client_id++;
 381 }
 382
 383 void uh_close_fds(void)
 384 {
 385         struct client *cl;
 386
 387         uloop_done();
 388         uh_close_listen_fds();
 389         list_for_each_entry(cl, &clients, list) {
 390                 close(cl->sfd.fd.fd);
 391                 if (cl->dispatch.close_fds)
 392                         cl->dispatch.close_fds(cl);
 393         }
 394 }