1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
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.
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.
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/>.
23 #include <sys/socket.h>
25 #include <asm/types.h>
26 #include <netinet/in.h>
27 #include <linux/rtnetlink.h>
34 #include "loopback-setup.h"
35 #include "socket-util.h"
37 #include "rtnl-util.h"
39 static int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
40 int *counter = userdata;
45 r = sd_rtnl_message_get_errno(m);
47 return r == -EEXIST ? 0 : r;
50 static int add_addresses(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
51 _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL;
54 r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET, 8, IFA_F_PERMANENT, RT_SCOPE_HOST, &ipv4);
58 r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address);
62 r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL);
68 if (!socket_ipv6_is_supported())
71 r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET6, 128, 0, 0, &ipv6);
75 r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback);
79 r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL);
88 static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
89 _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
92 r = sd_rtnl_message_link_new(RTM_SETLINK, if_loopback, &req);
96 r = sd_rtnl_message_link_set_flags(req, IFF_UP);
100 r = sd_rtnl_message_append_in_addr(req, IFA_LOCAL, ipv4_address);
104 r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
113 static int check_loopback(void) {
115 _cleanup_close_ int fd = -1;
118 struct sockaddr_in in;
120 .in.sin_family = AF_INET,
121 .in.sin_addr.s_addr = INADDR_LOOPBACK,
124 /* If we failed to set up the loop back device, check whether
125 * it might already be set up */
127 fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
131 if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
134 r = errno == EADDRNOTAVAIL ? 0 : -errno;
139 int loopback_setup(void) {
140 _cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL;
141 int r, if_loopback, counter = 0;
143 struct in_addr ipv4_address;
146 if_loopback = (int) if_nametoindex("lo");
147 if (if_loopback <= 0)
148 return errno ? -errno : -ENODEV;
150 ipv4_address.s_addr = htonl(INADDR_LOOPBACK);
152 r = sd_rtnl_open(0, &rtnl);
156 r = add_addresses(rtnl, if_loopback, &ipv4_address, &counter);
160 r = start_interface(rtnl, if_loopback, &ipv4_address, &counter);
164 while (counter > 0) {
165 r = sd_rtnl_wait(rtnl, 0);
169 r = sd_rtnl_process(rtnl, 0);
174 log_warning("Failed to configure loopback device: %s", strerror(-r));
180 if (eperm && check_loopback() < 0) {
181 log_warning("Failed to configure loopback device: %s", strerror(EPERM));