1 /*
2 * ll_map.c
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16 #include <syslog.h>
17 #include <fcntl.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
20 #include <string.h>
21
22 #include "libnetlink.h"
23 #include "ll_map.h"
24
25 extern unsigned int if_nametoindex (const char *);
26
27 struct idxmap
28 {
29 struct idxmap * next;
30 unsigned index;
31 int type;
32 int alen;
33 unsigned flags;
34 unsigned char addr[20];
35 char name[16];
36 };
37
38 static struct idxmap *idxmap[16];
39
ll_remember_index(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)40 int ll_remember_index(const struct sockaddr_nl *who,
41 struct nlmsghdr *n, void *arg)
42 {
43 int h;
44 struct ifinfomsg *ifi = NLMSG_DATA(n);
45 struct idxmap *im, **imp;
46 struct rtattr *tb[IFLA_MAX+1];
47
48 if (n->nlmsg_type != RTM_NEWLINK)
49 return 0;
50
51 if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
52 return -1;
53
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 h = ifi->ifi_index&0xF;
61
62 for (imp=&idxmap[h]; (im=*imp)!=NULL; imp = &im->next)
63 if (im->index == ifi->ifi_index)
64 break;
65
66 if (im == NULL) {
67 im = malloc(sizeof(*im));
68 if (im == NULL)
69 return 0;
70 im->next = *imp;
71 im->index = ifi->ifi_index;
72 *imp = im;
73 }
74
75 im->type = ifi->ifi_type;
76 im->flags = ifi->ifi_flags;
77 if (tb[IFLA_ADDRESS]) {
78 int alen;
79 im->alen = alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]);
80 if (alen > sizeof(im->addr))
81 alen = sizeof(im->addr);
82 memcpy(im->addr, RTA_DATA(tb[IFLA_ADDRESS]), alen);
83 } else {
84 im->alen = 0;
85 memset(im->addr, 0, sizeof(im->addr));
86 }
87 strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME]));
88 return 0;
89 }
90
ll_idx_n2a(unsigned idx,char * buf)91 const char *ll_idx_n2a(unsigned idx, char *buf)
92 {
93 struct idxmap *im;
94
95 if (idx == 0)
96 return "*";
97 for (im = idxmap[idx&0xF]; im; im = im->next)
98 if (im->index == idx)
99 return im->name;
100 snprintf(buf, 16, "if%d", idx);
101 return buf;
102 }
103
104
ll_index_to_name(unsigned idx)105 const char *ll_index_to_name(unsigned idx)
106 {
107 static char nbuf[16];
108
109 return ll_idx_n2a(idx, nbuf);
110 }
111
ll_index_to_type(unsigned idx)112 int ll_index_to_type(unsigned idx)
113 {
114 struct idxmap *im;
115
116 if (idx == 0)
117 return -1;
118 for (im = idxmap[idx&0xF]; im; im = im->next)
119 if (im->index == idx)
120 return im->type;
121 return -1;
122 }
123
ll_index_to_flags(unsigned idx)124 unsigned ll_index_to_flags(unsigned idx)
125 {
126 struct idxmap *im;
127
128 if (idx == 0)
129 return 0;
130
131 for (im = idxmap[idx&0xF]; im; im = im->next)
132 if (im->index == idx)
133 return im->flags;
134 return 0;
135 }
136
ll_index_to_addr(unsigned idx,unsigned char * addr,unsigned alen)137 unsigned ll_index_to_addr(unsigned idx, unsigned char *addr,
138 unsigned alen)
139 {
140 struct idxmap *im;
141
142 if (idx == 0)
143 return 0;
144
145 for (im = idxmap[idx&0xF]; im; im = im->next) {
146 if (im->index == idx) {
147 if (alen > sizeof(im->addr))
148 alen = sizeof(im->addr);
149 if (alen > im->alen)
150 alen = im->alen;
151 memcpy(addr, im->addr, alen);
152 return alen;
153 }
154 }
155 return 0;
156 }
157
ll_name_to_index(const char * name)158 unsigned ll_name_to_index(const char *name)
159 {
160 static char ncache[16];
161 static int icache;
162 struct idxmap *im;
163 int i;
164
165 if (name == NULL)
166 return 0;
167 if (icache && strcmp(name, ncache) == 0)
168 return icache;
169 for (i=0; i<16; i++) {
170 for (im = idxmap[i]; im; im = im->next) {
171 if (strcmp(im->name, name) == 0) {
172 icache = im->index;
173 strcpy(ncache, name);
174 return im->index;
175 }
176 }
177 }
178
179 return if_nametoindex(name);
180 }
181
ll_init_map(struct rtnl_handle * rth)182 int ll_init_map(struct rtnl_handle *rth)
183 {
184 if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
185 perror("Cannot send dump request");
186 exit(1);
187 }
188
189 if (rtnl_dump_filter(rth, ll_remember_index, &idxmap, NULL, NULL) < 0) {
190 fprintf(stderr, "Dump terminated\n");
191 exit(1);
192 }
193 return 0;
194 }
195