1 /*
2 * Copyright 2012 Daniel Drown <dan-android@drown.org>
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 * setif.c - network interface configuration
17 */
18 #include <errno.h>
19 #include <netinet/in.h>
20 #include <net/if.h>
21
22 #include <linux/rtnetlink.h>
23 #include <netlink/handlers.h>
24 #include <netlink/msg.h>
25
26 #include "netlink_msg.h"
27
28 /* function: add_address
29 * adds an IP address to/from an interface, returns 0 on success and <0 on failure
30 * ifname - name of interface to change
31 * family - address family (AF_INET, AF_INET6)
32 * address - pointer to a struct in_addr or in6_addr
33 * prefixlen - bitlength of network (example: 24 for AF_INET's 255.255.255.0)
34 * broadcast - broadcast address (only for AF_INET, ignored for AF_INET6)
35 */
add_address(const char * ifname,int family,const void * address,int prefixlen,const void * broadcast)36 int add_address(const char *ifname, int family, const void *address, int prefixlen, const void *broadcast) {
37 int retval;
38 size_t addr_size;
39 struct ifaddrmsg ifa;
40 struct nl_msg *msg = NULL;
41
42 addr_size = inet_family_size(family);
43 if(addr_size == 0) {
44 retval = -EAFNOSUPPORT;
45 goto cleanup;
46 }
47
48 memset(&ifa, 0, sizeof(ifa));
49 if (!(ifa.ifa_index = if_nametoindex(ifname))) {
50 retval = -ENODEV;
51 goto cleanup;
52 }
53 ifa.ifa_family = family;
54 ifa.ifa_prefixlen = prefixlen;
55 ifa.ifa_scope = RT_SCOPE_UNIVERSE;
56
57 msg = nlmsg_alloc_ifaddr(RTM_NEWADDR, NLM_F_ACK | NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE, &ifa);
58 if(!msg) {
59 retval = -ENOMEM;
60 goto cleanup;
61 }
62
63 if(nla_put(msg, IFA_LOCAL, addr_size, address) < 0) {
64 retval = -ENOMEM;
65 goto cleanup;
66 }
67 if(family == AF_INET6) {
68 // AF_INET6 gets IFA_LOCAL + IFA_ADDRESS
69 if(nla_put(msg, IFA_ADDRESS, addr_size, address) < 0) {
70 retval = -ENOMEM;
71 goto cleanup;
72 }
73 } else if(family == AF_INET) {
74 // AF_INET gets IFA_LOCAL + IFA_BROADCAST
75 if(nla_put(msg, IFA_BROADCAST, addr_size, broadcast) < 0) {
76 retval = -ENOMEM;
77 goto cleanup;
78 }
79 } else {
80 retval = -EAFNOSUPPORT;
81 goto cleanup;
82 }
83
84 retval = netlink_sendrecv(msg);
85
86 cleanup:
87 if(msg)
88 nlmsg_free(msg);
89
90 return retval;
91 }
92
93 /* function: if_up
94 * sets interface link state to up and sets mtu, returns 0 on success and <0 on failure
95 * ifname - interface name to change
96 * mtu - new mtu
97 */
if_up(const char * ifname,int mtu)98 int if_up(const char *ifname, int mtu) {
99 int retval = -1;
100 struct ifinfomsg ifi;
101 struct nl_msg *msg = NULL;
102
103 memset(&ifi, 0, sizeof(ifi));
104 if (!(ifi.ifi_index = if_nametoindex(ifname))) {
105 retval = -ENODEV;
106 goto cleanup;
107 }
108 ifi.ifi_change = IFF_UP;
109 ifi.ifi_flags = IFF_UP;
110
111 msg = nlmsg_alloc_ifinfo(RTM_SETLINK, NLM_F_ACK | NLM_F_REQUEST | NLM_F_ROOT, &ifi);
112 if(!msg) {
113 retval = -ENOMEM;
114 goto cleanup;
115 }
116
117 if(nla_put(msg, IFLA_MTU, 4, &mtu) < 0) {
118 retval = -ENOMEM;
119 goto cleanup;
120 }
121
122 retval = netlink_sendrecv(msg);
123
124 cleanup:
125 if(msg)
126 nlmsg_free(msg);
127
128 return retval;
129 }
130