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