1/*
2 * rtmon.c		RTnetlink listener.
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 <sys/time.h>
20#include <net/if.h>
21#include <netinet/in.h>
22#include <string.h>
23
24#include "SNAPSHOT.h"
25
26#include "utils.h"
27#include "libnetlink.h"
28
29int resolve_hosts = 0;
30static int init_phase = 1;
31
32static void write_stamp(FILE *fp)
33{
34	char buf[128];
35	struct nlmsghdr *n1 = (void*)buf;
36	struct timeval tv;
37
38	n1->nlmsg_type = 15;
39	n1->nlmsg_flags = 0;
40	n1->nlmsg_seq = 0;
41	n1->nlmsg_pid = 0;
42	n1->nlmsg_len = NLMSG_LENGTH(4*2);
43	gettimeofday(&tv, NULL);
44	((__u32*)NLMSG_DATA(n1))[0] = tv.tv_sec;
45	((__u32*)NLMSG_DATA(n1))[1] = tv.tv_usec;
46	fwrite((void*)n1, 1, NLMSG_ALIGN(n1->nlmsg_len), fp);
47}
48
49static int dump_msg(const struct sockaddr_nl *who, struct nlmsghdr *n,
50		    void *arg)
51{
52	FILE *fp = (FILE*)arg;
53	if (!init_phase)
54		write_stamp(fp);
55	fwrite((void*)n, 1, NLMSG_ALIGN(n->nlmsg_len), fp);
56	fflush(fp);
57	return 0;
58}
59
60void usage(void)
61{
62	fprintf(stderr, "Usage: rtmon file FILE [ all | LISTofOBJECTS]\n");
63	fprintf(stderr, "LISTofOBJECTS := [ link ] [ address ] [ route ]\n");
64	exit(-1);
65}
66
67int
68main(int argc, char **argv)
69{
70	FILE *fp;
71	struct rtnl_handle rth;
72	int family = AF_UNSPEC;
73	unsigned groups = ~0U;
74	int llink = 0;
75	int laddr = 0;
76	int lroute = 0;
77	char *file = NULL;
78
79	while (argc > 1) {
80		if (matches(argv[1], "-family") == 0) {
81			argc--;
82			argv++;
83			if (argc <= 1)
84				usage();
85			if (strcmp(argv[1], "inet") == 0)
86				family = AF_INET;
87			else if (strcmp(argv[1], "inet6") == 0)
88				family = AF_INET6;
89			else if (strcmp(argv[1], "link") == 0)
90				family = AF_INET6;
91			else if (strcmp(argv[1], "help") == 0)
92				usage();
93			else {
94				fprintf(stderr, "Protocol ID \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
95				exit(-1);
96			}
97		} else if (strcmp(argv[1], "-4") == 0) {
98			family = AF_INET;
99		} else if (strcmp(argv[1], "-6") == 0) {
100			family = AF_INET6;
101		} else if (strcmp(argv[1], "-0") == 0) {
102			family = AF_PACKET;
103		} else if (matches(argv[1], "-Version") == 0) {
104			printf("rtmon utility, iproute2-ss%s\n", SNAPSHOT);
105			exit(0);
106		} else if (matches(argv[1], "file") == 0) {
107			argc--;
108			argv++;
109			if (argc <= 1)
110				usage();
111			file = argv[1];
112		} else if (matches(argv[1], "link") == 0) {
113			llink=1;
114			groups = 0;
115		} else if (matches(argv[1], "address") == 0) {
116			laddr=1;
117			groups = 0;
118		} else if (matches(argv[1], "route") == 0) {
119			lroute=1;
120			groups = 0;
121		} else if (strcmp(argv[1], "all") == 0) {
122			groups = ~0U;
123		} else if (matches(argv[1], "help") == 0) {
124			usage();
125		} else {
126			fprintf(stderr, "Argument \"%s\" is unknown, try \"rtmon help\".\n", argv[1]);
127			exit(-1);
128		}
129		argc--;	argv++;
130	}
131
132	if (file == NULL) {
133		fprintf(stderr, "Not enough information: argument \"file\" is required\n");
134		exit(-1);
135	}
136	if (llink)
137		groups |= RTMGRP_LINK;
138	if (laddr) {
139		if (!family || family == AF_INET)
140			groups |= RTMGRP_IPV4_IFADDR;
141		if (!family || family == AF_INET6)
142			groups |= RTMGRP_IPV6_IFADDR;
143	}
144	if (lroute) {
145		if (!family || family == AF_INET)
146			groups |= RTMGRP_IPV4_ROUTE;
147		if (!family || family == AF_INET6)
148			groups |= RTMGRP_IPV6_ROUTE;
149	}
150
151	fp = fopen(file, "w");
152	if (fp == NULL) {
153		perror("Cannot fopen");
154		exit(-1);
155	}
156
157	if (rtnl_open(&rth, groups) < 0)
158		exit(1);
159
160	if (rtnl_wilddump_request(&rth, AF_UNSPEC, RTM_GETLINK) < 0) {
161		perror("Cannot send dump request");
162		exit(1);
163	}
164
165	write_stamp(fp);
166
167	if (rtnl_dump_filter(&rth, dump_msg, fp, NULL, NULL) < 0) {
168		fprintf(stderr, "Dump terminated\n");
169		return 1;
170	}
171
172	init_phase = 0;
173
174	if (rtnl_listen(&rth, dump_msg, (void*)fp) < 0)
175		exit(2);
176
177	exit(0);
178}
179