blob: 27cd90f34ed27e86628d537b412ec8f7587b34ab
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * This program is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU General Public License |
5 | * as published by the Free Software Foundation; either version |
6 | * 2 of the License, or (at your option) any later version. |
7 | * |
8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
9 | */ |
10 | |
11 | #include <net/if.h> /* struct ifreq and co. */ |
12 | |
13 | #include "libbb.h" |
14 | #include "libnetlink.h" |
15 | #include "ll_map.h" |
16 | |
17 | struct idxmap { |
18 | struct idxmap *next; |
19 | int index; |
20 | int type; |
21 | int alen; |
22 | unsigned flags; |
23 | unsigned char addr[8]; |
24 | char name[16]; |
25 | }; |
26 | |
27 | static struct idxmap **idxmap; /* treat as *idxmap[16] */ |
28 | |
29 | static struct idxmap *find_by_index(int idx) |
30 | { |
31 | struct idxmap *im; |
32 | |
33 | if (idxmap) |
34 | for (im = idxmap[idx & 0xF]; im; im = im->next) |
35 | if (im->index == idx) |
36 | return im; |
37 | return NULL; |
38 | } |
39 | |
40 | int FAST_FUNC ll_remember_index(const struct sockaddr_nl *who UNUSED_PARAM, |
41 | struct nlmsghdr *n, |
42 | void *arg UNUSED_PARAM) |
43 | { |
44 | int h; |
45 | struct ifinfomsg *ifi = NLMSG_DATA(n); |
46 | struct idxmap *im, **imp; |
47 | struct rtattr *tb[IFLA_MAX+1]; |
48 | |
49 | if (n->nlmsg_type != RTM_NEWLINK) |
50 | return 0; |
51 | |
52 | if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi))) |
53 | return -1; |
54 | |
55 | memset(tb, 0, sizeof(tb)); |
56 | parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n)); |
57 | if (tb[IFLA_IFNAME] == NULL) |
58 | return 0; |
59 | |
60 | if (!idxmap) |
61 | idxmap = xzalloc(sizeof(idxmap[0]) * 16); |
62 | |
63 | h = ifi->ifi_index & 0xF; |
64 | for (imp = &idxmap[h]; (im = *imp) != NULL; imp = &im->next) |
65 | if (im->index == ifi->ifi_index) |
66 | goto found; |
67 | |
68 | im = xmalloc(sizeof(*im)); |
69 | im->next = *imp; |
70 | im->index = ifi->ifi_index; |
71 | *imp = im; |
72 | found: |
73 | im->type = ifi->ifi_type; |
74 | im->flags = ifi->ifi_flags; |
75 | if (tb[IFLA_ADDRESS]) { |
76 | int alen; |
77 | im->alen = alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]); |
78 | if (alen > (int)sizeof(im->addr)) |
79 | alen = sizeof(im->addr); |
80 | memcpy(im->addr, RTA_DATA(tb[IFLA_ADDRESS]), alen); |
81 | } else { |
82 | im->alen = 0; |
83 | memset(im->addr, 0, sizeof(im->addr)); |
84 | } |
85 | strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME])); |
86 | return 0; |
87 | } |
88 | |
89 | const char FAST_FUNC *ll_idx_n2a(int idx, char *buf) |
90 | { |
91 | struct idxmap *im; |
92 | |
93 | if (idx == 0) |
94 | return "*"; |
95 | im = find_by_index(idx); |
96 | if (im) |
97 | return im->name; |
98 | snprintf(buf, 16, "if%d", idx); |
99 | return buf; |
100 | } |
101 | |
102 | |
103 | const char FAST_FUNC *ll_index_to_name(int idx) |
104 | { |
105 | static char nbuf[16]; |
106 | |
107 | return ll_idx_n2a(idx, nbuf); |
108 | } |
109 | |
110 | #ifdef UNUSED |
111 | int ll_index_to_type(int idx) |
112 | { |
113 | struct idxmap *im; |
114 | |
115 | if (idx == 0) |
116 | return -1; |
117 | im = find_by_index(idx); |
118 | if (im) |
119 | return im->type; |
120 | return -1; |
121 | } |
122 | #endif |
123 | |
124 | unsigned FAST_FUNC ll_index_to_flags(int idx) |
125 | { |
126 | struct idxmap *im; |
127 | |
128 | if (idx == 0) |
129 | return 0; |
130 | im = find_by_index(idx); |
131 | if (im) |
132 | return im->flags; |
133 | return 0; |
134 | } |
135 | |
136 | int FAST_FUNC xll_name_to_index(const char *name) |
137 | { |
138 | int ret = 0; |
139 | int sock_fd; |
140 | |
141 | /* caching is not warranted - no users which repeatedly call it */ |
142 | #ifdef UNUSED |
143 | static char ncache[16]; |
144 | static int icache; |
145 | |
146 | struct idxmap *im; |
147 | int i; |
148 | |
149 | if (name == NULL) |
150 | goto out; |
151 | if (icache && strcmp(name, ncache) == 0) { |
152 | ret = icache; |
153 | goto out; |
154 | } |
155 | if (idxmap) { |
156 | for (i = 0; i < 16; i++) { |
157 | for (im = idxmap[i]; im; im = im->next) { |
158 | if (strcmp(im->name, name) == 0) { |
159 | icache = im->index; |
160 | strcpy(ncache, name); |
161 | ret = im->index; |
162 | goto out; |
163 | } |
164 | } |
165 | } |
166 | } |
167 | /* We have not found the interface in our cache, but the kernel |
168 | * may still know about it. One reason is that we may be using |
169 | * module on-demand loading, which means that the kernel will |
170 | * load the module and make the interface exist only when |
171 | * we explicitely request it (check for dev_load() in net/core/dev.c). |
172 | * I can think of other similar scenario, but they are less common... |
173 | * Jean II */ |
174 | #endif |
175 | |
176 | sock_fd = socket(AF_INET, SOCK_DGRAM, 0); |
177 | if (sock_fd >= 0) { |
178 | struct ifreq ifr; |
179 | int tmp; |
180 | |
181 | strncpy_IFNAMSIZ(ifr.ifr_name, name); |
182 | ifr.ifr_ifindex = -1; |
183 | tmp = ioctl(sock_fd, SIOCGIFINDEX, &ifr); |
184 | close(sock_fd); |
185 | if (tmp >= 0) |
186 | /* In theory, we should redump the interface list |
187 | * to update our cache, this is left as an exercise |
188 | * to the reader... Jean II */ |
189 | ret = ifr.ifr_ifindex; |
190 | } |
191 | /* out:*/ |
192 | if (ret <= 0) |
193 | bb_error_msg_and_die("can't find device '%s'", name); |
194 | return ret; |
195 | } |
196 | |
197 | int FAST_FUNC ll_init_map(struct rtnl_handle *rth) |
198 | { |
199 | xrtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK); |
200 | xrtnl_dump_filter(rth, ll_remember_index, NULL); |
201 | return 0; |
202 | } |
203 |