1 /* external/dhcpcd/ifaddrs.c
2 **
3 ** Copyright 2011, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");.
6 ** you may not use this file except in compliance with the License..
7 ** You may obtain a copy of the License at.
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0.
10 **
11 ** Unless required by applicable law or agreed to in writing, software.
12 ** distributed under the License is distributed on an "AS IS" BASIS,.
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied..
14 ** See the License for the specific language governing permissions and.
15 ** limitations under the License.
16 */
17
18 #include <arpa/inet.h>
19 #include <sys/socket.h>
20 #include "ifaddrs.h"
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <unistd.h>
24 #include <sys/types.h>
25 #include <dirent.h>
26 #include <netinet/ether.h>
27 #include <netdb.h>
28 #include <linux/if_packet.h>
29 #include <netinet/if_ether.h>
30 #include <linux/if_arp.h>
31 #include <netutils/ifc.h>
32
get_interface(const char * name,sa_family_t family)33 struct ifaddrs *get_interface(const char *name, sa_family_t family)
34 {
35 unsigned addr, flags;
36 int masklen;
37 struct ifaddrs *ifa;
38 struct sockaddr_in *saddr = NULL;
39 struct sockaddr_in *smask = NULL;
40 struct sockaddr_ll *hwaddr = NULL;
41 unsigned char hwbuf[ETH_ALEN];
42
43 if (ifc_get_info(name, &addr, &masklen, &flags))
44 return NULL;
45
46 if ((family == AF_INET) && (addr == 0))
47 return NULL;
48
49 ifa = malloc(sizeof(struct ifaddrs));
50 if (!ifa)
51 return NULL;
52 memset(ifa, 0, sizeof(struct ifaddrs));
53
54 ifa->ifa_name = malloc(strlen(name)+1);
55 if (!ifa->ifa_name) {
56 free(ifa);
57 return NULL;
58 }
59 strcpy(ifa->ifa_name, name);
60 ifa->ifa_flags = flags;
61
62 if (family == AF_INET) {
63 saddr = malloc(sizeof(struct sockaddr_in));
64 if (saddr) {
65 saddr->sin_addr.s_addr = addr;
66 saddr->sin_family = family;
67 }
68 ifa->ifa_addr = (struct sockaddr *)saddr;
69
70 if (masklen != 0) {
71 smask = malloc(sizeof(struct sockaddr_in));
72 if (smask) {
73 smask->sin_addr.s_addr = prefixLengthToIpv4Netmask(masklen);
74 smask->sin_family = family;
75 }
76 }
77 ifa->ifa_netmask = (struct sockaddr *)smask;
78 } else if (family == AF_PACKET) {
79 if (!ifc_get_hwaddr(name, hwbuf)) {
80 hwaddr = malloc(sizeof(struct sockaddr_ll));
81 if (hwaddr) {
82 memset(hwaddr, 0, sizeof(struct sockaddr_ll));
83 hwaddr->sll_family = family;
84 /* hwaddr->sll_protocol = ETHERTYPE_IP; */
85 hwaddr->sll_hatype = ARPHRD_ETHER;
86 hwaddr->sll_halen = ETH_ALEN;
87 memcpy(hwaddr->sll_addr, hwbuf, ETH_ALEN);
88 }
89 }
90 ifa->ifa_addr = (struct sockaddr *)hwaddr;
91 ifa->ifa_netmask = (struct sockaddr *)smask;
92 }
93 return ifa;
94 }
95
getifaddrs(struct ifaddrs ** ifap)96 int getifaddrs(struct ifaddrs **ifap)
97 {
98 DIR *d;
99 struct dirent *de;
100 struct ifaddrs *ifa;
101 struct ifaddrs *ifah = NULL;
102
103 if (!ifap)
104 return -1;
105 *ifap = NULL;
106
107 if (ifc_init())
108 return -1;
109
110 d = opendir("/sys/class/net");
111 if (d == 0)
112 return -1;
113 while ((de = readdir(d))) {
114 if (de->d_name[0] == '.')
115 continue;
116 ifa = get_interface(de->d_name, AF_INET);
117 if (ifa != NULL) {
118 ifa->ifa_next = ifah;
119 ifah = ifa;
120 }
121 ifa = get_interface(de->d_name, AF_PACKET);
122 if (ifa != NULL) {
123 ifa->ifa_next = ifah;
124 ifah = ifa;
125 }
126 }
127 *ifap = ifah;
128 closedir(d);
129 ifc_close();
130 return 0;
131 }
132
freeifaddrs(struct ifaddrs * ifa)133 void freeifaddrs(struct ifaddrs *ifa)
134 {
135 struct ifaddrs *ifp;
136
137 while (ifa) {
138 ifp = ifa;
139 free(ifp->ifa_name);
140 if (ifp->ifa_addr)
141 free(ifp->ifa_addr);
142 if (ifp->ifa_netmask)
143 free(ifp->ifa_netmask);
144 ifa = ifa->ifa_next;
145 free(ifp);
146 }
147 }
148