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,
55 IFA_F_PERMANENT, RT_SCOPE_HOST, &ipv4);
59 r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address);
63 r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL);
69 if (!socket_ipv6_is_supported())
72 r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET6, 128,
73 IFA_F_PERMANENT, RT_SCOPE_HOST, &ipv6);
77 r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback);
81 r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL);
90 static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
91 _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
94 r = sd_rtnl_message_link_new(RTM_SETLINK, if_loopback, &req);
98 r = sd_rtnl_message_link_set_flags(req, IFF_UP);
102 r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
111 static int check_loopback(void) {
113 _cleanup_close_ int fd = -1;
116 struct sockaddr_in in;
118 .in.sin_family = AF_INET,
119 .in.sin_addr.s_addr = INADDR_LOOPBACK,
122 /* If we failed to set up the loop back device, check whether
123 * it might already be set up */
125 fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
129 if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
132 r = errno == EADDRNOTAVAIL ? 0 : -errno;
137 int loopback_setup(void) {
138 _cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL;
139 int r, if_loopback, counter = 0;
141 struct in_addr ipv4_address;
144 if_loopback = (int) if_nametoindex("lo");
145 if (if_loopback <= 0)
146 return errno ? -errno : -ENODEV;
148 ipv4_address.s_addr = htonl(INADDR_LOOPBACK);
150 r = sd_rtnl_open(0, &rtnl);
154 r = add_addresses(rtnl, if_loopback, &ipv4_address, &counter);
158 r = start_interface(rtnl, if_loopback, &ipv4_address, &counter);
162 while (counter > 0) {
163 r = sd_rtnl_wait(rtnl, 0);
167 r = sd_rtnl_process(rtnl, 0);
172 log_warning("Failed to configure loopback device: %s", strerror(-r));
178 if (eperm && check_loopback() < 0) {
179 log_warning("Failed to configure loopback device: %s", strerror(EPERM));