1
2/*
3 * Copyright (C) 2012 by Darren Reed.
4 *
5 * See the IPFILTER.LICENCE file for details on licencing.
6 */
7#include <sys/types.h>
8#include <sys/time.h>
9#include <sys/socket.h>
10
11#include <netinet/in.h>
12#include <net/if.h>
13
14#include <arpa/inet.h>
15
16#include <stdio.h>
17#include <stdlib.h>
18#include <fcntl.h>
19#include <string.h>
20#include <unistd.h>
21#include <syslog.h>
22#include <errno.h>
23#include <signal.h>
24
25#include "netinet/ip_compat.h"
26#include "netinet/ip_fil.h"
27#include "netinet/ip_state.h"
28#include "netinet/ip_nat.h"
29#include "netinet/ip_sync.h"
30
31int	main(int, char *[]);
32void	usage(const char *progname);
33
34int	terminate = 0;
35
36void usage(const char *progname) {
37	fprintf(stderr,
38		"Usage: %s <destination IP> <destination port> [remote IP]\n",
39		progname);
40}
41
42#if 0
43static void handleterm(int sig)
44{
45	terminate = sig;
46}
47#endif
48
49#define BUFFERLEN 1400
50
51int main(argc, argv)
52	int argc;
53	char *argv[];
54{
55	int nfd = -1 , lfd = -1;
56	int n1, n2, n3, magic, len, inbuf;
57	struct sockaddr_in sin;
58	struct sockaddr_in in;
59	char buff[BUFFERLEN];
60	synclogent_t *sl;
61	syncupdent_t *su;
62	synchdr_t *sh;
63	char *progname;
64
65	progname = strrchr(argv[0], '/');
66	if (progname) {
67		progname++;
68	} else {
69		progname = argv[0];
70	}
71
72	if (argc < 2) {
73		usage(progname);
74		exit(1);
75	}
76
77#if 0
78       	signal(SIGHUP, handleterm);
79       	signal(SIGINT, handleterm);
80       	signal(SIGTERM, handleterm);
81#endif
82
83	openlog(progname, LOG_PID, LOG_SECURITY);
84
85	lfd = open(IPSYNC_NAME, O_WRONLY);
86	if (lfd == -1) {
87		syslog(LOG_ERR, "Opening %s :%m", IPSYNC_NAME);
88		exit(1);
89	}
90
91	bzero((char *)&sin, sizeof(sin));
92	sin.sin_family = AF_INET;
93	if (argc > 1)
94		sin.sin_addr.s_addr = inet_addr(argv[1]);
95	if (argc > 2)
96		sin.sin_port = htons(atoi(argv[2]));
97	else
98		sin.sin_port = htons(43434);
99	if (argc > 3)
100		in.sin_addr.s_addr = inet_addr(argv[3]);
101	else
102		in.sin_addr.s_addr = 0;
103	in.sin_port = 0;
104
105	while(1) {
106
107		if (lfd != -1)
108			close(lfd);
109		if (nfd != -1)
110			close(nfd);
111
112		lfd = open(IPSYNC_NAME, O_WRONLY);
113		if (lfd == -1) {
114			syslog(LOG_ERR, "Opening %s :%m", IPSYNC_NAME);
115			goto tryagain;
116		}
117
118		nfd = socket(AF_INET, SOCK_DGRAM, 0);
119		if (nfd == -1) {
120			syslog(LOG_ERR, "Socket :%m");
121			goto tryagain;
122		}
123
124	        n1 = 1;
125                setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &n1, sizeof(n1));
126
127		if (bind(nfd, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
128			syslog(LOG_ERR, "Bind: %m");
129			goto tryagain;
130		}
131
132		syslog(LOG_INFO, "Listening to %s", inet_ntoa(sin.sin_addr));
133
134		inbuf = 0;
135		while (1) {
136
137
138			/*
139			 * XXX currently we do not check the source address
140			 * of a datagram, this can be a security risk
141			 */
142			n1 = read(nfd, buff+inbuf, BUFFERLEN-inbuf);
143
144			printf("header : %d bytes read (header = %d bytes)\n",
145			       n1, (int) sizeof(*sh));
146
147			if (n1 < 0) {
148				syslog(LOG_ERR, "Read error (header): %m");
149				goto tryagain;
150			}
151
152			if (n1 == 0) {
153				/* XXX can this happen??? */
154				syslog(LOG_ERR,
155				       "Read error (header) : No data");
156				sleep(1);
157				continue;
158			}
159
160			inbuf += n1;
161
162moreinbuf:
163			if (inbuf < sizeof(*sh)) {
164				continue; /* need more data */
165			}
166
167			sh = (synchdr_t *)buff;
168			len = ntohl(sh->sm_len);
169			magic = ntohl(sh->sm_magic);
170
171			if (magic != SYNHDRMAGIC) {
172				syslog(LOG_ERR, "Invalid header magic %x",
173				       magic);
174				goto tryagain;
175			}
176
177#define IPSYNC_DEBUG
178#ifdef IPSYNC_DEBUG
179			printf("v:%d p:%d len:%d magic:%x", sh->sm_v,
180			       sh->sm_p, len, magic);
181
182			if (sh->sm_cmd == SMC_CREATE)
183				printf(" cmd:CREATE");
184			else if (sh->sm_cmd == SMC_UPDATE)
185				printf(" cmd:UPDATE");
186			else
187				printf(" cmd:Unknown(%d)", sh->sm_cmd);
188
189			if (sh->sm_table == SMC_NAT)
190				printf(" table:NAT");
191			else if (sh->sm_table == SMC_STATE)
192				printf(" table:STATE");
193			else
194				printf(" table:Unknown(%d)", sh->sm_table);
195
196			printf(" num:%d\n", (u_32_t)ntohl(sh->sm_num));
197#endif
198
199			if (inbuf < sizeof(*sh) + len) {
200				continue; /* need more data */
201				goto tryagain;
202			}
203
204#ifdef IPSYNC_DEBUG
205			if (sh->sm_cmd == SMC_CREATE) {
206				sl = (synclogent_t *)buff;
207
208			} else if (sh->sm_cmd == SMC_UPDATE) {
209				su = (syncupdent_t *)buff;
210				if (sh->sm_p == IPPROTO_TCP) {
211					printf(" TCP Update: age %lu state %d/%d\n",
212					       su->sup_tcp.stu_age,
213					       su->sup_tcp.stu_state[0],
214					       su->sup_tcp.stu_state[1]);
215				}
216			} else {
217				printf("Unknown command\n");
218			}
219#endif
220
221			n2 = sizeof(*sh) + len;
222			n3 = write(lfd, buff, n2);
223			if (n3 <= 0) {
224				syslog(LOG_ERR, "%s: Write error: %m",
225				       IPSYNC_NAME);
226				goto tryagain;
227			}
228
229
230			if (n3 != n2) {
231				syslog(LOG_ERR, "%s: Incomplete write (%d/%d)",
232				       IPSYNC_NAME, n3, n2);
233				goto tryagain;
234			}
235
236			/* signal received? */
237			if (terminate)
238				break;
239
240			/* move buffer to the front,we might need to make
241			 * this more efficient, by using a rolling pointer
242			 * over the buffer and only copying it, when
243			 * we are reaching the end
244			 */
245			inbuf -= n2;
246			if (inbuf) {
247				bcopy(buff+n2, buff, inbuf);
248				printf("More data in buffer\n");
249				goto moreinbuf;
250			}
251		}
252
253		if (terminate)
254			break;
255tryagain:
256		sleep(1);
257	}
258
259
260	/* terminate */
261	if (lfd != -1)
262		close(lfd);
263	if (nfd != -1)
264		close(nfd);
265
266	syslog(LOG_ERR, "signal %d received, exiting...", terminate);
267
268	exit(1);
269}
270