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         char *name;
 208         char *val;
 209
 210         if (!*data) {
 211                 uloop_timeout_cancel(&cl->timeout);
 212                 cl->state = CLIENT_STATE_DATA;
 213                 client_header_complete(cl);
 214                 return;
 215         }
 216
 217         val = uh_split_header(data);
 218         if (!val) {
 219                 cl->state = CLIENT_STATE_DONE;
 220                 return;
 221         }
 222
 223         for (name = data; *name; name++)
 224                 if (isupper(*name))
 225                         *name = tolower(*name);
 226
 227         if (!strcasecmp(data, "Expect") &&
 228             !strcasecmp(val, "100-continue"))
 229                 cl->request.expect_cont = true;
 230
 231         blobmsg_add_string(&cl->hdr, data, val);
 232
 233         cl->state = CLIENT_STATE_HEADER;
 234 }
 235
 236 static bool client_data_cb(struct client *cl, char *buf, int len)
 237 {
 238         return false;
 239 }
 240
 241 static bool client_header_cb(struct client *cl, char *buf, int len)
 242 {
 243         char *newline;
 244         int line_len;
 245
 246         newline = strstr(buf, "\r\n");
 247         if (!newline)
 248                 return false;
 249
 250         *newline = 0;
 251         client_parse_header(cl, buf);
 252         line_len = newline + 2 - buf;
 253         ustream_consume(cl->us, line_len);
 254         if (cl->state == CLIENT_STATE_DATA)
 255                 client_data_cb(cl, newline + 2, len - line_len);
 256
 257         return true;
 258 }
 259
 260 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 261 static read_cb_t read_cbs[] = {
 262         [CLIENT_STATE_INIT] = client_init_cb,
 263         [CLIENT_STATE_HEADER] = client_header_cb,
 264         [CLIENT_STATE_DATA] = client_data_cb,
 265 };
 266
 267 static void client_read_cb(struct client *cl)
 268 {
 269         struct ustream *us = cl->us;
 270         char *str;
 271         int len;
 272
 273         do {
 274                 str = ustream_get_read_buf(us, &len);
 275                 if (!str)
 276                         break;
 277
 278                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 279                         break;
 280
 281                 if (!read_cbs[cl->state](cl, str, len)) {
 282                         if (len == us->r.buffer_len)
 283                                 uh_header_error(cl, 413, "Request Entity Too Large");
 284                         break;
 285                 }
 286         } while(1);
 287 }
 288
 289 static void client_close(struct client *cl)
 290 {
 291         uh_dispatch_done(cl);
 292         uloop_timeout_cancel(&cl->timeout);
 293         ustream_free(&cl->sfd.stream);
 294         close(cl->sfd.fd.fd);
 295         list_del(&cl->list);
 296         blob_buf_free(&cl->hdr);
 297         free(cl);
 298
 299         uh_unblock_listeners();
 300 }
 301
 302 static void client_ustream_read_cb(struct ustream *s, int bytes)
 303 {
 304         struct client *cl = container_of(s, struct client, sfd);
 305
 306         client_read_cb(cl);
 307 }
 308
 309 static void client_ustream_write_cb(struct ustream *s, int bytes)
 310 {
 311         struct client *cl = container_of(s, struct client, sfd);
 312
 313         if (cl->dispatch.write_cb)
 314                 cl->dispatch.write_cb(cl);
 315 }
 316
 317 static void client_notify_state(struct ustream *s)
 318 {
 319         struct client *cl = container_of(s, struct client, sfd);
 320
 321         if (!s->write_error) {
 322                 if (cl->state == CLIENT_STATE_DATA)
 323                         return;
 324
 325                 if (!s->eof || s->w.data_bytes)
 326                         return;
 327         }
 328
 329         return client_close(cl);
 330 }
 331
 332 static void set_addr(struct uh_addr *addr, void *src)
 333 {
 334         struct sockaddr_in *sin = src;
 335         struct sockaddr_in6 *sin6 = src;
 336
 337         addr->family = sin->sin_family;
 338         if (addr->family == AF_INET) {
 339                 addr->port = ntohs(sin->sin_port);
 340                 memcpy(&addr->in, &sin->sin_addr, sizeof(addr->in));
 341         } else {
 342                 addr->port = ntohs(sin6->sin6_port);
 343                 memcpy(&addr->in6, &sin6->sin6_addr, sizeof(addr->in6));
 344         }
 345 }
 346
 347 void uh_accept_client(int fd)
 348 {
 349         static struct client *next_client;
 350         struct client *cl;
 351         unsigned int sl;
 352         int sfd;
 353         static int client_id = 0;
 354         struct sockaddr_in6 addr;
 355
 356         if (!next_client)
 357                 next_client = calloc(1, sizeof(*next_client));
 358
 359         cl = next_client;
 360
 361         sl = sizeof(addr);
 362         sfd = accept(fd, (struct sockaddr *) &addr, &sl);
 363         if (sfd < 0)
 364                 return;
 365
 366         set_addr(&cl->peer_addr, &addr);
 367         sl = sizeof(addr);
 368         getsockname(fd, (struct sockaddr *) &addr, &sl);
 369         set_addr(&cl->srv_addr, &addr);
 370         cl->us = &cl->sfd.stream;
 371         cl->us->string_data = true;
 372         cl->us->notify_read = client_ustream_read_cb;
 373         cl->us->notify_write = client_ustream_write_cb;
 374         cl->us->notify_state = client_notify_state;
 375         ustream_fd_init(&cl->sfd, sfd);
 376
 377         cl->timeout.cb = client_timeout;
 378         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 379
 380         list_add_tail(&cl->list, &clients);
 381
 382         next_client = NULL;
 383         n_clients++;
 384         cl->id = client_id++;
 385 }
 386
 387 void uh_close_fds(void)
 388 {
 389         struct client *cl;
 390
 391         uloop_done();
 392         uh_close_listen_fds();
 393         list_for_each_entry(cl, &clients, list) {
 394                 close(cl->sfd.fd.fd);
 395                 if (cl->dispatch.close_fds)
 396                         cl->dispatch.close_fds(cl);
 397         }
 398 }