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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <sys/socket.h>
#include <net/if.h>
#include <asm/types.h>
#include <netinet/in.h>
#include <linux/rtnetlink.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "util.h"
#include "macro.h"
#include "loopback-setup.h"
#include "socket-util.h"
#include "sd-rtnl.h"
#include "rtnl-util.h"
static int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
int *counter = userdata;
int r;
(*counter) --;
r = sd_rtnl_message_get_errno(m);
return r == -EEXIST ? 0 : r;
}
static int add_addresses(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
_cleanup_sd_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL;
int r;
r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET, 8, IFA_F_PERMANENT, RT_SCOPE_HOST, &ipv4);
if (r < 0)
return r;
r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address);
if (r < 0)
return r;
r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL);
if (r < 0)
return r;
(*counter) ++;
if (!socket_ipv6_is_supported())
return 0;
r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET6, 128, 0, 0, &ipv6);
if (r < 0)
return r;
r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback);
if (r < 0)
return r;
r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL);
if (r < 0)
return r;
(*counter) ++;
return 0;
}
static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
_cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
int r;
r = sd_rtnl_message_link_new(RTM_NEWLINK, if_loopback, &req);
if (r < 0)
return r;
r = sd_rtnl_message_link_set_flags(req, IFF_UP);
if (r < 0)
return r;
r = sd_rtnl_message_append_in_addr(req, IFA_LOCAL, ipv4_address);
if (r < 0)
return r;
r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
if (r < 0)
return r;
(*counter) ++;
return 0;
}
static int check_loopback(void) {
int r;
_cleanup_close_ int fd = -1;
union {
struct sockaddr sa;
struct sockaddr_in in;
} sa = {
.in.sin_family = AF_INET,
.in.sin_addr.s_addr = INADDR_LOOPBACK,
};
/* If we failed to set up the loop back device, check whether
* it might already be set up */
fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
if (fd < 0)
return -errno;
if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
r = 1;
else
r = errno == EADDRNOTAVAIL ? 0 : -errno;
return r;
}
int loopback_setup(void) {
_cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL;
int r, if_loopback, counter = 0;
bool eperm = false;
struct in_addr ipv4_address;
errno = 0;
if_loopback = (int) if_nametoindex("lo");
if (if_loopback <= 0)
return errno ? -errno : -ENODEV;
ipv4_address.s_addr = htonl(INADDR_LOOPBACK);
r = sd_rtnl_open(0, &rtnl);
if (r < 0)
return r;
r = add_addresses(rtnl, if_loopback, &ipv4_address, &counter);
if (r < 0)
return r;
r = start_interface(rtnl, if_loopback, &ipv4_address, &counter);
if (r < 0)
return r;
while (counter > 0) {
r = sd_rtnl_wait(rtnl, 0);
if (r < 0)
return r;
r = sd_rtnl_process(rtnl, 0);
if (r < 0) {
if (r == -EPERM)
eperm = true;
else {
log_warning("Failed to configure loopback device: %s", strerror(-r));
return r;
}
}
}
if (eperm && check_loopback() < 0) {
log_warning("Failed to configure loopback device: %s", strerror(EPERM));
return -EPERM;
}
return 0;
}
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