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 void client_header_complete(struct client *cl)
 176 {
 177         uh_handle_request(cl);
 178 }
 179
 180 static void client_parse_header(struct client *cl, char *data)
 181 {
 182         char *name;
 183         char *val;
 184
 185         if (!*data) {
 186                 uloop_timeout_cancel(&cl->timeout);
 187                 cl->state = CLIENT_STATE_DATA;
 188                 client_header_complete(cl);
 189                 return;
 190         }
 191
 192         val = uh_split_header(data);
 193         if (!val) {
 194                 cl->state = CLIENT_STATE_DONE;
 195                 return;
 196         }
 197
 198         for (name = data; *name; name++)
 199                 if (isupper(*name))
 200                         *name = tolower(*name);
 201
 202         blobmsg_add_string(&cl->hdr, data, val);
 203
 204         cl->state = CLIENT_STATE_HEADER;
 205 }
 206
 207 static bool client_data_cb(struct client *cl, char *buf, int len)
 208 {
 209         return false;
 210 }
 211
 212 static bool client_header_cb(struct client *cl, char *buf, int len)
 213 {
 214         char *newline;
 215         int line_len;
 216
 217         newline = strstr(buf, "\r\n");
 218         if (!newline)
 219                 return false;
 220
 221         *newline = 0;
 222         client_parse_header(cl, buf);
 223         line_len = newline + 2 - buf;
 224         ustream_consume(cl->us, line_len);
 225         if (cl->state == CLIENT_STATE_DATA)
 226                 client_data_cb(cl, newline + 2, len - line_len);
 227
 228         return true;
 229 }
 230
 231 typedef bool (*read_cb_t)(struct client *cl, char *buf, int len);
 232 static read_cb_t read_cbs[] = {
 233         [CLIENT_STATE_INIT] = client_init_cb,
 234         [CLIENT_STATE_HEADER] = client_header_cb,
 235         [CLIENT_STATE_DATA] = client_data_cb,
 236 };
 237
 238 static void client_read_cb(struct client *cl)
 239 {
 240         struct ustream *us = cl->us;
 241         char *str;
 242         int len;
 243
 244         do {
 245                 str = ustream_get_read_buf(us, &len);
 246                 if (!str)
 247                         break;
 248
 249                 if (cl->state >= array_size(read_cbs) || !read_cbs[cl->state])
 250                         break;
 251
 252                 if (!read_cbs[cl->state](cl, str, len)) {
 253                         if (len == us->r.buffer_len)
 254                                 uh_header_error(cl, 413, "Request Entity Too Large");
 255                         break;
 256                 }
 257         } while(1);
 258 }
 259
 260 static void client_close(struct client *cl)
 261 {
 262         uh_dispatch_done(cl);
 263         uloop_timeout_cancel(&cl->timeout);
 264         ustream_free(&cl->sfd.stream);
 265         close(cl->sfd.fd.fd);
 266         list_del(&cl->list);
 267         blob_buf_free(&cl->hdr);
 268         free(cl);
 269
 270         uh_unblock_listeners();
 271 }
 272
 273 static void client_ustream_read_cb(struct ustream *s, int bytes)
 274 {
 275         struct client *cl = container_of(s, struct client, sfd);
 276
 277         client_read_cb(cl);
 278 }
 279
 280 static void client_ustream_write_cb(struct ustream *s, int bytes)
 281 {
 282         struct client *cl = container_of(s, struct client, sfd);
 283
 284         if (cl->dispatch.write_cb)
 285                 cl->dispatch.write_cb(cl);
 286 }
 287
 288 static void client_notify_state(struct ustream *s)
 289 {
 290         struct client *cl = container_of(s, struct client, sfd);
 291
 292         if (!s->write_error) {
 293                 if (cl->state == CLIENT_STATE_DATA)
 294                         return;
 295
 296                 if (!s->eof || s->w.data_bytes)
 297                         return;
 298         }
 299
 300         return client_close(cl);
 301 }
 302
 303 void uh_accept_client(int fd)
 304 {
 305         static struct client *next_client;
 306         struct client *cl;
 307         unsigned int sl;
 308         int sfd;
 309         static int client_id = 0;
 310
 311         if (!next_client)
 312                 next_client = calloc(1, sizeof(*next_client));
 313
 314         cl = next_client;
 315
 316         sl = sizeof(cl->peeraddr);
 317         sfd = accept(fd, (struct sockaddr *) &cl->peeraddr, &sl);
 318         if (sfd < 0)
 319                 return;
 320
 321         sl = sizeof(cl->servaddr);
 322         getsockname(fd, (struct sockaddr *) &cl->servaddr, &sl);
 323         cl->us = &cl->sfd.stream;
 324         cl->us->string_data = true;
 325         cl->us->notify_read = client_ustream_read_cb;
 326         cl->us->notify_write = client_ustream_write_cb;
 327         cl->us->notify_state = client_notify_state;
 328         ustream_fd_init(&cl->sfd, sfd);
 329
 330         cl->timeout.cb = client_timeout;
 331         uloop_timeout_set(&cl->timeout, conf.network_timeout * 1000);
 332
 333         list_add_tail(&cl->list, &clients);
 334
 335         next_client = NULL;
 336         n_clients++;
 337         cl->id = client_id++;
 338 }
 339
 340 void uh_close_fds(void)
 341 {
 342         struct client *cl;
 343
 344         uloop_done();
 345         uh_close_listen_fds();
 346         list_for_each_entry(cl, &clients, list) {
 347                 close(cl->sfd.fd.fd);
 348                 if (cl->dispatch.close_fds)
 349                         cl->dispatch.close_fds(cl);
 350         }
 351 }