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/*
* Copyright 2013 Google Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
/*
* Author: ncardwell@google.com (Neal Cardwell)
*
* Implementation for various network utilities.
*/
#include "net_utils.h"
#include <stdlib.h>
#include <net/if.h>
#include <unistd.h>
#include "logging.h"
static void verbose_system(const char *command)
{
int result;
DEBUGP("running: '%s'\n", command);
result = system(command);
DEBUGP("result: %d\n", result);
if (result != 0)
DEBUGP("error executing command '%s'\n", command);
}
/* Configure a local IPv4 address and netmask for the device */
static void net_add_ipv4_address(const char *dev_name,
const struct ip_address *ip,
int prefix_len)
{
char *command = NULL;
char ip_string[ADDR_STR_LEN];
ip_to_string(ip, ip_string);
#ifdef linux
asprintf(&command, "ip addr add %s/%d dev %s > /dev/null 2>&1",
ip_string, prefix_len, dev_name);
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
asprintf(&command, "/sbin/ifconfig %s %s/%d alias",
dev_name, ip_string, prefix_len);
#endif /* defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) */
verbose_system(command);
free(command);
}
/* Configure a local IPv6 address and prefix length for the device */
static void net_add_ipv6_address(const char *dev_name,
const struct ip_address *ip,
int prefix_len)
{
char *command = NULL;
char ip_string[ADDR_STR_LEN];
ip_to_string(ip, ip_string);
#ifdef linux
asprintf(&command, "ip addr add %s/%d dev %s > /dev/null 2>&1",
ip_string, prefix_len, dev_name);
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
asprintf(&command, "/sbin/ifconfig %s inet6 %s/%d",
dev_name, ip_string, prefix_len);
#endif /* defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) */
verbose_system(command);
free(command);
/* Wait for IPv6 duplicate address detection to converge,
* so that this address no longer shows as "tentative".
* e.g. "ip addr show" shows:
* inet6 fd3d:fa7b:d17d::36/48 scope global tentative
*/
#ifdef linux
if (!strstr(dev_name, "tun"))
sleep(2);
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
sleep(3);
#endif
}
void net_add_dev_address(const char *dev_name,
const struct ip_address *ip,
int prefix_len)
{
switch (ip->address_family) {
case AF_INET:
net_add_ipv4_address(dev_name, ip, prefix_len);
break;
case AF_INET6:
net_add_ipv6_address(dev_name, ip, prefix_len);
break;
default:
assert(!"bad family");
break;
}
}
void net_del_dev_address(const char *dev_name,
const struct ip_address *ip,
int prefix_len)
{
char *command = NULL;
char ip_string[ADDR_STR_LEN];
ip_to_string(ip, ip_string);
#ifdef linux
asprintf(&command, "ip addr del %s/%d dev %s > /dev/null 2>&1",
ip_string, prefix_len, dev_name);
#endif
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
asprintf(&command, "/sbin/ifconfig %s %s %s/%d -alias",
dev_name,
ip->address_family == AF_INET6 ? "inet6" : "",
ip_string, prefix_len);
#endif /* defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) */
verbose_system(command);
free(command);
}
/* In general we want to avoid configuring a new IP address on an
* interface, because we do not want to pay the latency penaly
* (e.g. it takes about one second for IPv6 duplicate address
* detection). So if we find the IP configured the correct local
* network device, then we're done, and we short-circuit and return
* immediately. Otherwise remove the address from the current device
* and add it on the newly-requested device.
*/
void net_setup_dev_address(const char *dev_name,
const struct ip_address *ip,
int prefix_len)
{
char cur_dev_name[IFNAMSIZ];
bool found = get_ip_device(ip, cur_dev_name);
DEBUGP("net_setup_dev_address: found: %d\n", found);
if (found && strcmp(cur_dev_name, dev_name) == 0) {
DEBUGP("net_setup_dev_address: found on correct device\n");
return;
}
if (found)
net_del_dev_address(cur_dev_name, ip, prefix_len);
net_add_dev_address(dev_name, ip, prefix_len);
}
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