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 <errno.h>
  23 #include <stddef.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26 #include <unistd.h>
  27
  28 #include "alloc-util.h"
  29 #include "fd-util.h"
  30 #include "macro.h"
  31 #include "missing.h"
  32 #include "mkdir.h"
  33 #include "selinux-util.h"
  34 #include "socket-util.h"
  35 #include "util.h"
  36
  37 int socket_address_listen(
  38                 const SocketAddress *a,
  39                 int flags,
  40                 int backlog,
  41                 SocketAddressBindIPv6Only only,
  42                 const char *bind_to_device,
  43                 bool reuse_port,
  44                 bool free_bind,
  45                 bool transparent,
  46                 mode_t directory_mode,
  47                 mode_t socket_mode,
  48                 const char *label) {
  49
  50         _cleanup_close_ int fd = -1;
  51         int r, one;
  52
  53         assert(a);
  54
  55         r = socket_address_verify(a);
  56         if (r < 0)
  57                 return r;
  58
  59         if (socket_address_family(a) == AF_INET6 && !socket_ipv6_is_supported())
  60                 return -EAFNOSUPPORT;
  61
  62         if (label) {
  63                 r = mac_selinux_create_socket_prepare(label);
  64                 if (r < 0)
  65                         return r;
  66         }
  67
  68         fd = socket(socket_address_family(a), a->type | flags, a->protocol);
  69         r = fd < 0 ? -errno : 0;
  70
  71         if (label)
  72                 mac_selinux_create_socket_clear();
  73
  74         if (r < 0)
  75                 return r;
  76
  77         if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {
  78                 int flag = only == SOCKET_ADDRESS_IPV6_ONLY;
  79
  80                 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
  81                         return -errno;
  82         }
  83
  84         if (socket_address_family(a) == AF_INET || socket_address_family(a) == AF_INET6) {
  85                 if (bind_to_device)
  86                         if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
  87                                 return -errno;
  88
  89                 if (reuse_port) {
  90                         one = 1;
  91                         if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0)
  92                                 log_warning_errno(errno, "SO_REUSEPORT failed: %m");
  93                 }
  94
  95                 if (free_bind) {
  96                         one = 1;
  97                         if (setsockopt(fd, IPPROTO_IP, IP_FREEBIND, &one, sizeof(one)) < 0)
  98                                 log_warning_errno(errno, "IP_FREEBIND failed: %m");
  99                 }
 100
 101                 if (transparent) {
 102                         one = 1;
 103                         if (setsockopt(fd, IPPROTO_IP, IP_TRANSPARENT, &one, sizeof(one)) < 0)
 104                                 log_warning_errno(errno, "IP_TRANSPARENT failed: %m");
 105                 }
 106         }
 107
 108         one = 1;
 109         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
 110                 return -errno;
 111
 112         if (socket_address_family(a) == AF_UNIX && a->sockaddr.un.sun_path[0] != 0) {
 113                 mode_t old_mask;
 114
 115                 /* Create parents */
 116                 mkdir_parents_label(a->sockaddr.un.sun_path, directory_mode);
 117
 118                 /* Enforce the right access mode for the socket */
 119                 old_mask = umask(~ socket_mode);
 120
 121                 r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);
 122
 123                 if (r < 0 && errno == EADDRINUSE) {
 124                         /* Unlink and try again */
 125                         unlink(a->sockaddr.un.sun_path);
 126                         r = bind(fd, &a->sockaddr.sa, a->size);
 127                 }
 128
 129                 umask(old_mask);
 130         } else
 131                 r = bind(fd, &a->sockaddr.sa, a->size);
 132
 133         if (r < 0)
 134                 return -errno;
 135
 136         if (socket_address_can_accept(a))
 137                 if (listen(fd, backlog) < 0)
 138                         return -errno;
 139
 140         r = fd;
 141         fd = -1;
 142
 143         return r;
 144 }
 145
 146 int make_socket_fd(int log_level, const char* address, int flags) {
 147         SocketAddress a;
 148         int fd, r;
 149
 150         r = socket_address_parse(&a, address);
 151         if (r < 0)
 152                 return log_error_errno(r, "Failed to parse socket address \"%s\": %m", address);
 153
 154         fd = socket_address_listen(&a, flags, SOMAXCONN, SOCKET_ADDRESS_DEFAULT,
 155                                    NULL, false, false, false, 0755, 0644, NULL);
 156         if (fd < 0 || log_get_max_level() >= log_level) {
 157                 _cleanup_free_ char *p = NULL;
 158
 159                 r = socket_address_print(&a, &p);
 160                 if (r < 0)
 161                         return log_error_errno(r, "socket_address_print(): %m");
 162
 163                 if (fd < 0)
 164                         log_error_errno(fd, "Failed to listen on %s: %m", p);
 165                 else
 166                         log_full(log_level, "Listening on %s", p);
 167         }
 168
 169         return fd;
 170 }