net.c

   1 /* Copyright (C) 2007 Keith Rarick and Philotic Inc.
   2
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 3 of the License, or
   6  * (at your option) any later version.
   7
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <netdb.h>
  18 #include <unistd.h>
  19 #include <fcntl.h>
  20 #include <string.h>
  21 #include <errno.h>
  22 #include <sys/socket.h>
  23 #include <netinet/in.h>
  24 #include <netinet/tcp.h>
  25 #include "dat.h"
  26 #include "sd-daemon.h"
  27
  28 int
  29 make_server_socket(char *host, char *port)
  30 {
  31     int fd = -1, flags, r;
  32     struct linger linger = {0, 0};
  33     struct addrinfo *airoot, *ai, hints;
  34
  35     /* See if we got a listen fd from systemd. If so, all socket options etc
  36      * are already set, so we check that the fd is a TCP listen socket and
  37      * return. */
  38     r = sd_listen_fds(1);
  39     if (r < 0) {
  40         return twarn("sd_listen_fds"), -1;
  41     }
  42     if (r > 0) {
  43         if (r > 1) {
  44             twarnx("inherited more than one listen socket;"
  45                    " ignoring all but the first");
  46             r = 1;
  47         }
  48         fd = SD_LISTEN_FDS_START;
  49         r = sd_is_socket_inet(fd, 0, SOCK_STREAM, 1, 0);
  50         if (r < 0) {
  51             errno = -r;
  52             twarn("sd_is_socket_inet");
  53             return -1;
  54         }
  55         if (!r) {
  56             twarnx("inherited fd is not a TCP listen socket");
  57             return -1;
  58         }
  59         return fd;
  60     }
  61
  62     memset(&hints, 0, sizeof(hints));
  63     hints.ai_family = PF_UNSPEC;
  64     hints.ai_socktype = SOCK_STREAM;
  65     hints.ai_flags = AI_PASSIVE;
  66     r = getaddrinfo(host, port, &hints, &airoot);
  67     if (r == -1)
  68       return twarn("getaddrinfo()"), -1;
  69
  70     for(ai = airoot; ai; ai = ai->ai_next) {
  71       fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
  72       if (fd == -1) {
  73         twarn("socket()");
  74         continue;
  75       }
  76
  77       flags = fcntl(fd, F_GETFL, 0);
  78       if (flags < 0) {
  79         twarn("getting flags");
  80         close(fd);
  81         continue;
  82       }
  83
  84       r = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
  85       if (r == -1) {
  86         twarn("setting O_NONBLOCK");
  87         close(fd);
  88         continue;
  89       }
  90
  91       flags = 1;
  92       setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &flags, sizeof flags);
  93       setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &flags, sizeof flags);
  94       setsockopt(fd, SOL_SOCKET, SO_LINGER,   &linger, sizeof linger);
  95       setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &flags, sizeof flags);
  96
  97       r = bind(fd, ai->ai_addr, ai->ai_addrlen);
  98       if (r == -1) {
  99         twarn("bind()");
 100         close(fd);
 101         continue;
 102       }
 103
 104       r = listen(fd, 1024);
 105       if (r == -1) {
 106         twarn("listen()");
 107         close(fd);
 108         continue;
 109       }
 110
 111       break;
 112     }
 113
 114     freeaddrinfo(airoot);
 115
 116     if(ai == NULL)
 117       fd = -1;
 118
 119     return fd;
 120 }