listen.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 <sys/types.h>
  21 #include <sys/socket.h>
  22 #include <netinet/tcp.h>
  23 #include <netdb.h>
  24
  25 #include "uhttpd.h"
  26
  27 struct listener {
  28         struct list_head list;
  29         struct uloop_fd fd;
  30         int socket;
  31         int n_clients;
  32         struct sockaddr_in6 addr;
  33         bool tls;
  34         bool blocked;
  35 };
  36
  37 static LIST_HEAD(listeners);
  38 static int n_blocked;
  39
  40 void uh_close_listen_fds(void)
  41 {
  42         struct listener *l;
  43
  44         list_for_each_entry(l, &listeners, list)
  45                 close(l->fd.fd);
  46 }
  47
  48 static void uh_block_listener(struct listener *l)
  49 {
  50         uloop_fd_delete(&l->fd);
  51         n_blocked++;
  52         l->blocked = true;
  53 }
  54
  55 void uh_unblock_listeners(void)
  56 {
  57         struct listener *l;
  58
  59         if (!n_blocked && conf.max_requests &&
  60             n_clients >= conf.max_requests)
  61                 return;
  62
  63         list_for_each_entry(l, &listeners, list) {
  64                 if (!l->blocked)
  65                         continue;
  66
  67                 n_blocked--;
  68                 l->blocked = false;
  69                 uloop_fd_add(&l->fd, ULOOP_READ);
  70         }
  71 }
  72
  73 static void listener_cb(struct uloop_fd *fd, unsigned int events)
  74 {
  75         struct listener *l = container_of(fd, struct listener, fd);
  76
  77         uh_accept_client(fd->fd);
  78
  79         if (conf.max_requests && n_clients >= conf.max_requests)
  80                 uh_block_listener(l);
  81 }
  82
  83 void uh_setup_listeners(void)
  84 {
  85         struct listener *l;
  86         int yes = 1;
  87
  88         list_for_each_entry(l, &listeners, list) {
  89                 int sock = l->fd.fd;
  90
  91                 /* TCP keep-alive */
  92                 if (conf.tcp_keepalive > 0) {
  93 #ifdef linux
  94                         int tcp_ka_idl, tcp_ka_int, tcp_ka_cnt;
  95
  96                         tcp_ka_idl = 1;
  97                         tcp_ka_cnt = 3;
  98                         tcp_ka_int = conf.tcp_keepalive;
  99
 100                         setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,  &tcp_ka_idl, sizeof(tcp_ka_idl));
 101                         setsockopt(sock, SOL_TCP, TCP_KEEPINTVL, &tcp_ka_int, sizeof(tcp_ka_int));
 102                         setsockopt(sock, SOL_TCP, TCP_KEEPCNT,   &tcp_ka_cnt, sizeof(tcp_ka_cnt));
 103 #endif
 104
 105                         setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof(yes));
 106                 }
 107
 108                 l->fd.cb = listener_cb;
 109                 uloop_fd_add(&l->fd, ULOOP_READ);
 110         }
 111 }
 112
 113 int uh_socket_bind(const char *host, const char *port, bool tls)
 114 {
 115         int sock = -1;
 116         int yes = 1;
 117         int status;
 118         int bound = 0;
 119         struct listener *l = NULL;
 120         struct addrinfo *addrs = NULL, *p = NULL;
 121         static struct addrinfo hints = {
 122                 .ai_family = AF_UNSPEC,
 123                 .ai_socktype = SOCK_STREAM,
 124                 .ai_flags = AI_PASSIVE,
 125         };
 126
 127         if ((status = getaddrinfo(host, port, &hints, &addrs)) != 0) {
 128                 fprintf(stderr, "getaddrinfo(): %s\n", gai_strerror(status));
 129                 return 0;
 130         }
 131
 132         /* try to bind a new socket to each found address */
 133         for (p = addrs; p; p = p->ai_next) {
 134                 /* get the socket */
 135                 sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
 136                 if (sock < 0) {
 137                         perror("socket()");
 138                         goto error;
 139                 }
 140
 141                 /* "address already in use" */
 142                 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes))) {
 143                         perror("setsockopt()");
 144                         goto error;
 145                 }
 146
 147                 /* required to get parallel v4 + v6 working */
 148                 if (p->ai_family == AF_INET6 &&
 149                     setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
 150                         perror("setsockopt()");
 151                         goto error;
 152                 }
 153
 154                 /* bind */
 155                 if (bind(sock, p->ai_addr, p->ai_addrlen) < 0) {
 156                         perror("bind()");
 157                         goto error;
 158                 }
 159
 160                 /* listen */
 161                 if (listen(sock, UH_LIMIT_CLIENTS) < 0) {
 162                         perror("listen()");
 163                         goto error;
 164                 }
 165
 166                 fd_cloexec(sock);
 167
 168                 l = calloc(1, sizeof(*l));
 169                 if (!l)
 170                         goto error;
 171
 172                 l->fd.fd = sock;
 173                 l->tls = tls;
 174                 list_add_tail(&l->list, &listeners);
 175                 bound++;
 176
 177                 continue;
 178
 179 error:
 180                 if (sock > -1)
 181                         close(sock);
 182         }
 183
 184         freeaddrinfo(addrs);
 185
 186         return bound;
 187 }