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8041b5ba LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
cbc06dcd | 4 | This file is part of systemd. |
8041b5ba LP |
5 | |
6 | Copyright 2008-2011 Lennart Poettering | |
7 | ||
cbc06dcd TG |
8 | systemd is free software; you can redistribute it and/or modify it |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
8041b5ba | 12 | |
cbc06dcd TG |
13 | systemd is distributed in the hope that it will be useful, but |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
8041b5ba LP |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
16 | Lesser General Public License for more details. | |
17 | ||
cbc06dcd TG |
18 | You should have received a copy of the GNU Lesser General Public License |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
8041b5ba LP |
20 | ***/ |
21 | ||
22 | #include <sys/socket.h> | |
23 | #include <sys/un.h> | |
24 | #include <asm/types.h> | |
25 | #include <inttypes.h> | |
26 | #include <linux/netlink.h> | |
27 | #include <linux/rtnetlink.h> | |
28 | #include <string.h> | |
29 | #include <assert.h> | |
30 | #include <errno.h> | |
31 | #include <limits.h> | |
32 | #include <arpa/inet.h> | |
33 | #include <unistd.h> | |
8041b5ba LP |
34 | #include <stdlib.h> |
35 | ||
1df2a0fc | 36 | #include "ifconf.h" |
8041b5ba | 37 | |
d73c3269 | 38 | #define SEQ 4711 |
8041b5ba | 39 | |
d73c3269 ZJS |
40 | static int read_reply(int fd, struct address **list, unsigned *n_list) { |
41 | ssize_t bytes; | |
42 | struct cmsghdr *cmsg; | |
43 | struct ucred *ucred; | |
44 | struct nlmsghdr *p; | |
45 | uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred))]; | |
8041b5ba LP |
46 | struct { |
47 | struct nlmsghdr hdr; | |
d73c3269 ZJS |
48 | struct ifaddrmsg ifaddrmsg; |
49 | uint8_t payload[16*1024]; | |
50 | } resp; | |
51 | struct iovec iov = { | |
52 | .iov_base = &resp, | |
53 | .iov_len = sizeof(resp), | |
54 | }; | |
55 | struct msghdr msg = { | |
56 | .msg_name = NULL, | |
57 | .msg_namelen = 0, | |
58 | .msg_iov = &iov, | |
59 | .msg_iovlen = 1, | |
60 | .msg_control = cred_buffer, | |
61 | .msg_controllen = sizeof(cred_buffer), | |
62 | .msg_flags = 0, | |
63 | }; | |
64 | ||
65 | assert(fd >= 0); | |
66 | assert(list); | |
67 | ||
68 | bytes = recvmsg(fd, &msg, 0); | |
69 | if (bytes < 0) | |
8041b5ba LP |
70 | return -errno; |
71 | ||
d73c3269 ZJS |
72 | cmsg = CMSG_FIRSTHDR(&msg); |
73 | if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS) | |
74 | return -EIO; | |
8041b5ba | 75 | |
d73c3269 ZJS |
76 | ucred = (struct ucred*) CMSG_DATA(cmsg); |
77 | if (ucred->uid != 0 || ucred->pid != 0) | |
78 | return 0; | |
8041b5ba | 79 | |
d73c3269 ZJS |
80 | for (p = &resp.hdr; bytes > 0; p = NLMSG_NEXT(p, bytes)) { |
81 | struct ifaddrmsg *ifaddrmsg; | |
82 | struct rtattr *a; | |
83 | size_t l; | |
84 | void *local = NULL, *address = NULL; | |
8041b5ba | 85 | |
d73c3269 ZJS |
86 | if (!NLMSG_OK(p, (size_t) bytes)) |
87 | return -EIO; | |
8041b5ba | 88 | |
d73c3269 ZJS |
89 | if (p->nlmsg_seq != SEQ) |
90 | continue; | |
91 | ||
92 | if (p->nlmsg_type == NLMSG_DONE) | |
93 | return 1; | |
94 | ||
95 | if (p->nlmsg_type == NLMSG_ERROR) { | |
96 | struct nlmsgerr *nlmsgerr; | |
8041b5ba | 97 | |
d73c3269 ZJS |
98 | nlmsgerr = NLMSG_DATA(p); |
99 | return -nlmsgerr->error; | |
8041b5ba LP |
100 | } |
101 | ||
d73c3269 | 102 | if (p->nlmsg_type != RTM_NEWADDR) |
8041b5ba LP |
103 | continue; |
104 | ||
d73c3269 | 105 | ifaddrmsg = NLMSG_DATA(p); |
8041b5ba | 106 | |
d73c3269 ZJS |
107 | if (ifaddrmsg->ifa_family != AF_INET && |
108 | ifaddrmsg->ifa_family != AF_INET6) | |
109 | continue; | |
8041b5ba | 110 | |
d73c3269 ZJS |
111 | if (ifaddrmsg->ifa_scope == RT_SCOPE_HOST || |
112 | ifaddrmsg->ifa_scope == RT_SCOPE_NOWHERE) | |
113 | continue; | |
8041b5ba | 114 | |
d73c3269 ZJS |
115 | if (ifaddrmsg->ifa_flags & IFA_F_DEPRECATED) |
116 | continue; | |
8041b5ba | 117 | |
d73c3269 ZJS |
118 | l = NLMSG_PAYLOAD(p, sizeof(struct ifaddrmsg)); |
119 | a = IFA_RTA(ifaddrmsg); | |
8041b5ba | 120 | |
d73c3269 | 121 | while (RTA_OK(a, l)) { |
8041b5ba | 122 | |
d73c3269 ZJS |
123 | if (a->rta_type == IFA_ADDRESS) |
124 | address = RTA_DATA(a); | |
125 | else if (a->rta_type == IFA_LOCAL) | |
126 | local = RTA_DATA(a); | |
8041b5ba | 127 | |
d73c3269 ZJS |
128 | a = RTA_NEXT(a, l); |
129 | } | |
8041b5ba | 130 | |
d73c3269 ZJS |
131 | if (local) |
132 | address = local; | |
8041b5ba | 133 | |
d73c3269 ZJS |
134 | if (!address) |
135 | continue; | |
8041b5ba | 136 | |
d73c3269 ZJS |
137 | *list = realloc(*list, (*n_list+1) * sizeof(struct address)); |
138 | if (!*list) | |
139 | return -ENOMEM; | |
8041b5ba | 140 | |
d73c3269 ZJS |
141 | (*list)[*n_list].family = ifaddrmsg->ifa_family; |
142 | (*list)[*n_list].scope = ifaddrmsg->ifa_scope; | |
143 | memcpy((*list)[*n_list].address, | |
144 | address, ifaddrmsg->ifa_family == AF_INET ? 4 : 16); | |
145 | (*list)[*n_list].ifindex = ifaddrmsg->ifa_index; | |
8041b5ba | 146 | |
d73c3269 ZJS |
147 | (*n_list)++; |
148 | } | |
8041b5ba | 149 | |
d73c3269 ZJS |
150 | return 0; |
151 | } | |
8041b5ba | 152 | |
8041b5ba | 153 | |
d73c3269 | 154 | int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) { |
8041b5ba | 155 | |
d73c3269 ZJS |
156 | struct { |
157 | struct nlmsghdr hdr; | |
158 | struct rtgenmsg gen; | |
159 | } req = { { | |
160 | .nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)), | |
161 | .nlmsg_type = RTM_GETADDR, | |
162 | .nlmsg_flags = NLM_F_REQUEST|NLM_F_DUMP|NLM_F_ACK, | |
163 | .nlmsg_seq = SEQ, | |
164 | .nlmsg_pid = 0, | |
165 | }, { | |
166 | .rtgen_family = AF_UNSPEC, | |
167 | } | |
168 | }; | |
169 | int r, on = 1; | |
170 | struct address *list = NULL; | |
171 | unsigned n_list = 0; | |
7464b33d | 172 | int fd; |
8041b5ba | 173 | |
d73c3269 ZJS |
174 | fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); |
175 | if (fd < 0) | |
176 | return -errno; | |
8041b5ba | 177 | |
7464b33d ZJS |
178 | if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) { |
179 | r = -errno; | |
180 | goto finish; | |
181 | } | |
8041b5ba | 182 | |
7464b33d ZJS |
183 | if (send(fd, &req, req.hdr.nlmsg_len, 0) < 0) { |
184 | r = -errno; | |
185 | goto finish; | |
186 | } | |
8041b5ba | 187 | |
d73c3269 ZJS |
188 | while((r = read_reply(fd, &list, &n_list)) == 0) |
189 | ; | |
8041b5ba | 190 | |
7464b33d ZJS |
191 | finish: |
192 | close(fd); | |
193 | ||
d73c3269 | 194 | if (r < 0) { |
8041b5ba | 195 | free(list); |
d73c3269 | 196 | return r; |
8041b5ba LP |
197 | } |
198 | ||
7ff7394d ZJS |
199 | if (n_list) |
200 | qsort(list, n_list, sizeof(struct address), address_compare); | |
d73c3269 ZJS |
201 | |
202 | *_list = list; | |
203 | *_n_list = n_list; | |
204 | ||
205 | return 0; | |
8041b5ba | 206 | } |