src/basic/socket-label.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <sys/stat.h>
  26 #include <stddef.h>
  27
  28 #include "macro.h"
  29 #include "util.h"
  30 #include "mkdir.h"
  31 #include "missing.h"
  32 #include "selinux-util.h"
  33 #include "socket-util.h"
  34
  35 int socket_address_listen(
  36                 const SocketAddress *a,
  37                 int flags,
  38                 int backlog,
  39                 SocketAddressBindIPv6Only only,
  40                 const char *bind_to_device,
  41                 bool reuse_port,
  42                 bool free_bind,
  43                 bool transparent,
  44                 mode_t directory_mode,
  45                 mode_t socket_mode,
  46                 const char *label) {
  47
  48         _cleanup_close_ int fd = -1;
  49         int r, one;
  50
  51         assert(a);
  52
  53         r = socket_address_verify(a);
  54         if (r < 0)
  55                 return r;
  56
  57         if (socket_address_family(a) == AF_INET6 && !socket_ipv6_is_supported())
  58                 return -EAFNOSUPPORT;
  59
  60         if (label) {
  61                 r = mac_selinux_create_socket_prepare(label);
  62                 if (r < 0)
  63                         return r;
  64         }
  65
  66         fd = socket(socket_address_family(a), a->type | flags, a->protocol);
  67         r = fd < 0 ? -errno : 0;
  68
  69         if (label)
  70                 mac_selinux_create_socket_clear();
  71
  72         if (r < 0)
  73                 return r;
  74
  75         if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {
  76                 int flag = only == SOCKET_ADDRESS_IPV6_ONLY;
  77
  78                 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
  79                         return -errno;
  80         }
  81
  82         if (socket_address_family(a) == AF_INET || socket_address_family(a) == AF_INET6) {
  83                 if (bind_to_device)
  84                         if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
  85                                 return -errno;
  86
  87                 if (reuse_port) {
  88                         one = 1;
  89                         if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0)
  90                                 log_warning_errno(errno, "SO_REUSEPORT failed: %m");
  91                 }
  92
  93                 if (free_bind) {
  94                         one = 1;
  95                         if (setsockopt(fd, IPPROTO_IP, IP_FREEBIND, &one, sizeof(one)) < 0)
  96                                 log_warning_errno(errno, "IP_FREEBIND failed: %m");
  97                 }
  98
  99                 if (transparent) {
 100                         one = 1;
 101                         if (setsockopt(fd, IPPROTO_IP, IP_TRANSPARENT, &one, sizeof(one)) < 0)
 102                                 log_warning_errno(errno, "IP_TRANSPARENT failed: %m");
 103                 }
 104         }
 105
 106         one = 1;
 107         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 108                 return -errno;
 109
 110         if (socket_address_family(a) == AF_UNIX && a->sockaddr.un.sun_path[0] != 0) {
 111                 mode_t old_mask;
 112
 113                 /* Create parents */
 114                 mkdir_parents_label(a->sockaddr.un.sun_path, directory_mode);
 115
 116                 /* Enforce the right access mode for the socket */
 117                 old_mask = umask(~ socket_mode);
 118
 119                 r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);
 120
 121                 if (r < 0 && errno == EADDRINUSE) {
 122                         /* Unlink and try again */
 123                         unlink(a->sockaddr.un.sun_path);
 124                         r = bind(fd, &a->sockaddr.sa, a->size);
 125                 }
 126
 127                 umask(old_mask);
 128         } else
 129                 r = bind(fd, &a->sockaddr.sa, a->size);
 130
 131         if (r < 0)
 132                 return -errno;
 133
 134         if (socket_address_can_accept(a))
 135                 if (listen(fd, backlog) < 0)
 136                         return -errno;
 137
 138         r = fd;
 139         fd = -1;
 140
 141         return r;
 142 }
 143
 144 int make_socket_fd(int log_level, const char* address, int flags) {
 145         SocketAddress a;
 146         int fd, r;
 147
 148         r = socket_address_parse(&a, address);
 149         if (r < 0)
 150                 return log_error_errno(r, "Failed to parse socket address \"%s\": %m", address);
 151
 152         fd = socket_address_listen(&a, flags, SOMAXCONN, SOCKET_ADDRESS_DEFAULT,
 153                                    NULL, false, false, false, 0755, 0644, NULL);
 154         if (fd < 0 || log_get_max_level() >= log_level) {
 155                 _cleanup_free_ char *p = NULL;
 156
 157                 r = socket_address_print(&a, &p);
 158                 if (r < 0)
 159                         return log_error_errno(r, "socket_address_print(): %m");
 160
 161                 if (fd < 0)
 162                         log_error_errno(fd, "Failed to listen on %s: %m", p);
 163                 else
 164                         log_full(log_level, "Listening on %s", p);
 165         }
 166
 167         return fd;
 168 }