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1 /*
2  * ipmaddr.c		"ip maddress".
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/ioctl.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
21 #include <arpa/inet.h>
22 #include <string.h>
23 
24 #include <linux/netdevice.h>
25 #include <linux/if.h>
26 #include <linux/if_arp.h>
27 #include <linux/sockios.h>
28 
29 #include "rt_names.h"
30 #include "utils.h"
31 
32 static struct {
33 	char *dev;
34 	int  family;
35 } filter;
36 
37 static void usage(void) __attribute__((noreturn));
38 
usage(void)39 static void usage(void)
40 {
41 	fprintf(stderr, "Usage: ip maddr [ add | del ] MULTIADDR dev STRING\n");
42 	fprintf(stderr, "       ip maddr show [ dev STRING ]\n");
43 	exit(-1);
44 }
45 
parse_hex(char * str,unsigned char * addr,size_t size)46 static int parse_hex(char *str, unsigned char *addr, size_t size)
47 {
48 	int len=0;
49 
50 	while (*str && (len < 2 * size)) {
51 		int tmp;
52 		if (str[1] == 0)
53 			return -1;
54 		if (sscanf(str, "%02x", &tmp) != 1)
55 			return -1;
56 		addr[len] = tmp;
57 		len++;
58 		str += 2;
59 	}
60 	return len;
61 }
62 
63 struct ma_info
64 {
65 	struct ma_info *next;
66 	int		index;
67 	int		users;
68 	char		*features;
69 	char		name[IFNAMSIZ];
70 	inet_prefix	addr;
71 };
72 
maddr_ins(struct ma_info ** lst,struct ma_info * m)73 void maddr_ins(struct ma_info **lst, struct ma_info *m)
74 {
75 	struct ma_info *mp;
76 
77 	for (; (mp=*lst) != NULL; lst = &mp->next) {
78 		if (mp->index > m->index)
79 			break;
80 	}
81 	m->next = *lst;
82 	*lst = m;
83 }
84 
read_dev_mcast(struct ma_info ** result_p)85 void read_dev_mcast(struct ma_info **result_p)
86 {
87 	char buf[256];
88 	FILE *fp = fopen("/proc/net/dev_mcast", "r");
89 
90 	if (!fp)
91 		return;
92 
93 	while (fgets(buf, sizeof(buf), fp)) {
94 		char hexa[256];
95 		struct ma_info m;
96 		int len;
97 		int st;
98 
99 		memset(&m, 0, sizeof(m));
100 		sscanf(buf, "%d%s%d%d%s", &m.index, m.name, &m.users, &st,
101 		       hexa);
102 		if (filter.dev && strcmp(filter.dev, m.name))
103 			continue;
104 
105 		m.addr.family = AF_PACKET;
106 
107 		len = parse_hex(hexa, (unsigned char*)&m.addr.data, sizeof (m.addr.data));
108 		if (len >= 0) {
109 			struct ma_info *ma = malloc(sizeof(m));
110 
111 			memcpy(ma, &m, sizeof(m));
112 			ma->addr.bytelen = len;
113 			ma->addr.bitlen = len<<3;
114 			if (st)
115 				ma->features = "static";
116 			maddr_ins(result_p, ma);
117 		}
118 	}
119 	fclose(fp);
120 }
121 
read_igmp(struct ma_info ** result_p)122 void read_igmp(struct ma_info **result_p)
123 {
124 	struct ma_info m;
125 	char buf[256];
126 	FILE *fp = fopen("/proc/net/igmp", "r");
127 
128 	if (!fp)
129 		return;
130 	memset(&m, 0, sizeof(m));
131 	if (!fgets(buf, sizeof(buf), fp)) {
132 		fclose(fp);
133 		return;
134 	}
135 
136 	m.addr.family = AF_INET;
137 	m.addr.bitlen = 32;
138 	m.addr.bytelen = 4;
139 
140 	while (fgets(buf, sizeof(buf), fp)) {
141 		struct ma_info *ma;
142 
143 		if (buf[0] != '\t') {
144 			sscanf(buf, "%d%s", &m.index, m.name);
145 			continue;
146 		}
147 
148 		if (filter.dev && strcmp(filter.dev, m.name))
149 			continue;
150 
151 		sscanf(buf, "%08x%d", (__u32*)&m.addr.data, &m.users);
152 
153 		ma = malloc(sizeof(m));
154 		memcpy(ma, &m, sizeof(m));
155 		maddr_ins(result_p, ma);
156 	}
157 	fclose(fp);
158 }
159 
160 
read_igmp6(struct ma_info ** result_p)161 void read_igmp6(struct ma_info **result_p)
162 {
163 	char buf[256];
164 	FILE *fp = fopen("/proc/net/igmp6", "r");
165 
166 	if (!fp)
167 		return;
168 
169 	while (fgets(buf, sizeof(buf), fp)) {
170 		char hexa[256];
171 		struct ma_info m;
172 		int len;
173 
174 		memset(&m, 0, sizeof(m));
175 		sscanf(buf, "%d%s%s%d", &m.index, m.name, hexa, &m.users);
176 
177 		if (filter.dev && strcmp(filter.dev, m.name))
178 			continue;
179 
180 		m.addr.family = AF_INET6;
181 
182 		len = parse_hex(hexa, (unsigned char*)&m.addr.data, sizeof (m.addr.data));
183 		if (len >= 0) {
184 			struct ma_info *ma = malloc(sizeof(m));
185 
186 			memcpy(ma, &m, sizeof(m));
187 
188 			ma->addr.bytelen = len;
189 			ma->addr.bitlen = len<<3;
190 			maddr_ins(result_p, ma);
191 		}
192 	}
193 	fclose(fp);
194 }
195 
print_maddr(FILE * fp,struct ma_info * list)196 static void print_maddr(FILE *fp, struct ma_info *list)
197 {
198 	fprintf(fp, "\t");
199 
200 	if (list->addr.family == AF_PACKET) {
201 		SPRINT_BUF(b1);
202 		fprintf(fp, "link  %s", ll_addr_n2a((unsigned char*)list->addr.data,
203 						    list->addr.bytelen, 0,
204 						    b1, sizeof(b1)));
205 	} else {
206 		char abuf[256];
207 		switch(list->addr.family) {
208 		case AF_INET:
209 			fprintf(fp, "inet  ");
210 			break;
211 		case AF_INET6:
212 			fprintf(fp, "inet6 ");
213 			break;
214 		default:
215 			fprintf(fp, "family %d ", list->addr.family);
216 			break;
217 		}
218 		fprintf(fp, "%s",
219 			format_host(list->addr.family,
220 				    -1,
221 				    list->addr.data,
222 				    abuf, sizeof(abuf)));
223 	}
224 	if (list->users != 1)
225 		fprintf(fp, " users %d", list->users);
226 	if (list->features)
227 		fprintf(fp, " %s", list->features);
228 	fprintf(fp, "\n");
229 }
230 
print_mlist(FILE * fp,struct ma_info * list)231 static void print_mlist(FILE *fp, struct ma_info *list)
232 {
233 	int cur_index = 0;
234 
235 	for (; list; list = list->next) {
236 		if (oneline) {
237 			cur_index = list->index;
238 			fprintf(fp, "%d:\t%s%s", cur_index, list->name, _SL_);
239 		} else if (cur_index != list->index) {
240 			cur_index = list->index;
241 			fprintf(fp, "%d:\t%s\n", cur_index, list->name);
242 		}
243 		print_maddr(fp, list);
244 	}
245 }
246 
multiaddr_list(int argc,char ** argv)247 static int multiaddr_list(int argc, char **argv)
248 {
249 	struct ma_info *list = NULL;
250 
251 	if (!filter.family)
252 		filter.family = preferred_family;
253 
254 	while (argc > 0) {
255 		if (1) {
256 			if (strcmp(*argv, "dev") == 0) {
257 				NEXT_ARG();
258 			}
259 			if (matches(*argv, "help") == 0)
260 				usage();
261 			if (filter.dev)
262 				duparg2("dev", *argv);
263 			filter.dev = *argv;
264 		}
265 		argv++; argc--;
266 	}
267 
268 	if (!filter.family || filter.family == AF_PACKET)
269 		read_dev_mcast(&list);
270 	if (!filter.family || filter.family == AF_INET)
271 		read_igmp(&list);
272 	if (!filter.family || filter.family == AF_INET6)
273 		read_igmp6(&list);
274 	print_mlist(stdout, list);
275 	return 0;
276 }
277 
multiaddr_modify(int cmd,int argc,char ** argv)278 int multiaddr_modify(int cmd, int argc, char **argv)
279 {
280 	struct ifreq ifr;
281 	int fd;
282 
283 	memset(&ifr, 0, sizeof(ifr));
284 
285 	if (cmd == RTM_NEWADDR)
286 		cmd = SIOCADDMULTI;
287 	else
288 		cmd = SIOCDELMULTI;
289 
290 	while (argc > 0) {
291 		if (strcmp(*argv, "dev") == 0) {
292 			NEXT_ARG();
293 			if (ifr.ifr_name[0])
294 				duparg("dev", *argv);
295 			strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
296 		} else {
297 			if (matches(*argv, "address") == 0) {
298 				NEXT_ARG();
299 			}
300 			if (matches(*argv, "help") == 0)
301 				usage();
302 			if (ifr.ifr_hwaddr.sa_data[0])
303 				duparg("address", *argv);
304 			if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
305 					14, *argv) < 0) {
306 				fprintf(stderr, "Error: \"%s\" is not a legal ll address.\n", *argv);
307 				exit(1);
308 			}
309 		}
310 		argc--; argv++;
311 	}
312 	if (ifr.ifr_name[0] == 0) {
313 		fprintf(stderr, "Not enough information: \"dev\" is required.\n");
314 		exit(-1);
315 	}
316 
317 	fd = socket(AF_INET, SOCK_DGRAM, 0);
318 	if (fd < 0) {
319 		perror("Cannot create socket");
320 		exit(1);
321 	}
322 	if (ioctl(fd, cmd, (char*)&ifr) != 0) {
323 		perror("ioctl");
324 		exit(1);
325 	}
326 	close(fd);
327 
328 	exit(0);
329 }
330 
331 
do_multiaddr(int argc,char ** argv)332 int do_multiaddr(int argc, char **argv)
333 {
334 	if (argc < 1)
335 		return multiaddr_list(0, NULL);
336 	if (matches(*argv, "add") == 0)
337 		return multiaddr_modify(RTM_NEWADDR, argc-1, argv+1);
338 	if (matches(*argv, "delete") == 0)
339 		return multiaddr_modify(RTM_DELADDR, argc-1, argv+1);
340 	if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
341 	    || matches(*argv, "lst") == 0)
342 		return multiaddr_list(argc-1, argv+1);
343 	if (matches(*argv, "help") == 0)
344 		usage();
345 	fprintf(stderr, "Command \"%s\" is unknown, try \"ip maddr help\".\n", *argv);
346 	exit(-1);
347 }
348