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/*
* Copyright 2012 Daniel Drown <dan-android@drown.org>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* setif.c - network interface configuration
*/
#include <errno.h>
#include <netinet/in.h>
#include <net/if.h>
#include <linux/rtnetlink.h>
#include <netlink/handlers.h>
#include <netlink/msg.h>
#include "logging.h"
#include "netlink_msg.h"
#define DEBUG_OPTNAME(a) case (a): { optname = #a; break; }
/* function: add_address
* adds an IP address to/from an interface, returns 0 on success and <0 on failure
* ifname - name of interface to change
* family - address family (AF_INET, AF_INET6)
* address - pointer to a struct in_addr or in6_addr
* prefixlen - bitlength of network (example: 24 for AF_INET's 255.255.255.0)
* broadcast - broadcast address (only for AF_INET, ignored for AF_INET6)
*/
int add_address(const char *ifname, int family, const void *address, int prefixlen, const void *broadcast) {
int retval;
size_t addr_size;
struct ifaddrmsg ifa;
struct nl_msg *msg = NULL;
addr_size = inet_family_size(family);
if(addr_size == 0) {
retval = -EAFNOSUPPORT;
goto cleanup;
}
memset(&ifa, 0, sizeof(ifa));
if (!(ifa.ifa_index = if_nametoindex(ifname))) {
retval = -ENODEV;
goto cleanup;
}
ifa.ifa_family = family;
ifa.ifa_prefixlen = prefixlen;
ifa.ifa_scope = RT_SCOPE_UNIVERSE;
msg = nlmsg_alloc_ifaddr(RTM_NEWADDR, NLM_F_ACK | NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE, &ifa);
if(!msg) {
retval = -ENOMEM;
goto cleanup;
}
if(nla_put(msg, IFA_LOCAL, addr_size, address) < 0) {
retval = -ENOMEM;
goto cleanup;
}
if(family == AF_INET6) {
// AF_INET6 gets IFA_LOCAL + IFA_ADDRESS
if(nla_put(msg, IFA_ADDRESS, addr_size, address) < 0) {
retval = -ENOMEM;
goto cleanup;
}
} else if(family == AF_INET) {
// AF_INET gets IFA_LOCAL + IFA_BROADCAST
if(nla_put(msg, IFA_BROADCAST, addr_size, broadcast) < 0) {
retval = -ENOMEM;
goto cleanup;
}
} else {
retval = -EAFNOSUPPORT;
goto cleanup;
}
retval = netlink_sendrecv(msg);
cleanup:
if(msg)
nlmsg_free(msg);
return retval;
}
/* function: if_up
* sets interface link state to up and sets mtu, returns 0 on success and <0 on failure
* ifname - interface name to change
* mtu - new mtu
*/
int if_up(const char *ifname, int mtu) {
int retval = -1;
struct ifinfomsg ifi;
struct nl_msg *msg = NULL;
memset(&ifi, 0, sizeof(ifi));
if (!(ifi.ifi_index = if_nametoindex(ifname))) {
retval = -ENODEV;
goto cleanup;
}
ifi.ifi_change = IFF_UP;
ifi.ifi_flags = IFF_UP;
msg = nlmsg_alloc_ifinfo(RTM_SETLINK, NLM_F_ACK | NLM_F_REQUEST | NLM_F_ROOT, &ifi);
if(!msg) {
retval = -ENOMEM;
goto cleanup;
}
if(nla_put(msg, IFLA_MTU, 4, &mtu) < 0) {
retval = -ENOMEM;
goto cleanup;
}
retval = netlink_sendrecv(msg);
cleanup:
if(msg)
nlmsg_free(msg);
return retval;
}
static int do_anycast_setsockopt(int sock, int what, struct in6_addr *addr, int ifindex) {
struct ipv6_mreq mreq = { *addr, ifindex };
char *optname;
int ret;
switch (what) {
DEBUG_OPTNAME(IPV6_JOIN_ANYCAST)
DEBUG_OPTNAME(IPV6_LEAVE_ANYCAST)
default:
optname = "???";
break;
}
ret = setsockopt(sock, SOL_IPV6, what, &mreq, sizeof(mreq));
if (ret) {
logmsg(ANDROID_LOG_ERROR, "%s: setsockopt(%s): %s", __func__, optname, strerror(errno));
}
return ret;
}
/* function: add_anycast_address
* adds an anycast IPv6 address to an interface, returns 0 on success and <0 on failure
* sock - the socket to add the address to
* addr - the IP address to add
* ifname - name of interface to add the address to
*/
int add_anycast_address(int sock, struct in6_addr *addr, const char *ifname) {
int ifindex;
ifindex = if_nametoindex(ifname);
if (!ifindex) {
logmsg(ANDROID_LOG_ERROR, "%s: unknown ifindex for interface %s", __func__, ifname);
return -ENODEV;
}
return do_anycast_setsockopt(sock, IPV6_JOIN_ANYCAST, addr, ifindex);
}
/* function: del_anycast_address
* removes an anycast IPv6 address from the system, returns 0 on success and <0 on failure
* sock - the socket to remove from, must have had the address added via add_anycast_address
* addr - the IP address to remove
*/
int del_anycast_address(int sock, struct in6_addr *addr) {
return do_anycast_setsockopt(sock, IPV6_LEAVE_ANYCAST, addr, 0);
}
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