listen.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  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                 l->fd.cb(&l->fd, ULOOP_READ);
  68             if (n_clients >= conf.max_requests)
  69                         break;
  70
  71                 n_blocked--;
  72                 l->blocked = false;
  73                 uloop_fd_add(&l->fd, ULOOP_READ);
  74         }
  75 }
  76
  77 static void listener_cb(struct uloop_fd *fd, unsigned int events)
  78 {
  79         struct listener *l = container_of(fd, struct listener, fd);
  80
  81         while (1) {
  82                 if (!uh_accept_client(fd->fd, l->tls))
  83                         break;
  84         }
  85
  86         if (conf.max_requests && n_clients >= conf.max_requests)
  87                 uh_block_listener(l);
  88 }
  89
  90 void uh_setup_listeners(void)
  91 {
  92         struct listener *l;
  93         int yes = 1;
  94
  95         list_for_each_entry(l, &listeners, list) {
  96                 int sock = l->fd.fd;
  97
  98                 /* TCP keep-alive */
  99                 if (conf.tcp_keepalive > 0) {
 100 #ifdef linux
 101                         int tcp_ka_idl, tcp_ka_int, tcp_ka_cnt;
 102
 103                         tcp_ka_idl = 1;
 104                         tcp_ka_cnt = 3;
 105                         tcp_ka_int = conf.tcp_keepalive;
 106
 107                         setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,  &tcp_ka_idl, sizeof(tcp_ka_idl));
 108                         setsockopt(sock, SOL_TCP, TCP_KEEPINTVL, &tcp_ka_int, sizeof(tcp_ka_int));
 109                         setsockopt(sock, SOL_TCP, TCP_KEEPCNT,   &tcp_ka_cnt, sizeof(tcp_ka_cnt));
 110 #endif
 111
 112                         setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, &yes, sizeof(yes));
 113                 }
 114
 115                 l->fd.cb = listener_cb;
 116                 uloop_fd_add(&l->fd, ULOOP_READ);
 117         }
 118 }
 119
 120 int uh_socket_bind(const char *host, const char *port, bool tls)
 121 {
 122         int sock = -1;
 123         int yes = 1;
 124         int status;
 125         int bound = 0;
 126         struct listener *l = NULL;
 127         struct addrinfo *addrs = NULL, *p = NULL;
 128         static struct addrinfo hints = {
 129                 .ai_family = AF_UNSPEC,
 130                 .ai_socktype = SOCK_STREAM,
 131                 .ai_flags = AI_PASSIVE,
 132         };
 133
 134         if ((status = getaddrinfo(host, port, &hints, &addrs)) != 0) {
 135                 fprintf(stderr, "getaddrinfo(): %s\n", gai_strerror(status));
 136                 return 0;
 137         }
 138
 139         /* try to bind a new socket to each found address */
 140         for (p = addrs; p; p = p->ai_next) {
 141                 /* get the socket */
 142                 sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
 143                 if (sock < 0) {
 144                         perror("socket()");
 145                         goto error;
 146                 }
 147
 148                 /* "address already in use" */
 149                 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes))) {
 150                         perror("setsockopt()");
 151                         goto error;
 152                 }
 153
 154                 /* required to get parallel v4 + v6 working */
 155                 if (p->ai_family == AF_INET6 &&
 156                     setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)) < 0) {
 157                         perror("setsockopt()");
 158                         goto error;
 159                 }
 160
 161                 /* bind */
 162                 if (bind(sock, p->ai_addr, p->ai_addrlen) < 0) {
 163                         perror("bind()");
 164                         goto error;
 165                 }
 166
 167                 /* listen */
 168                 if (listen(sock, UH_LIMIT_CLIENTS) < 0) {
 169                         perror("listen()");
 170                         goto error;
 171                 }
 172
 173                 fd_cloexec(sock);
 174
 175                 l = calloc(1, sizeof(*l));
 176                 if (!l)
 177                         goto error;
 178
 179                 l->fd.fd = sock;
 180                 l->tls = tls;
 181                 list_add_tail(&l->list, &listeners);
 182                 bound++;
 183
 184                 continue;
 185
 186 error:
 187                 if (sock > -1)
 188                         close(sock);
 189         }
 190
 191         freeaddrinfo(addrs);
 192
 193         return bound;
 194 }