0.4.4/experiments/udp_snoop.c

/*
 *  Copyright (C) 2006  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright  
 *     notice, this list of conditions and the following disclaimer in the 
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE   
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *
 *
 *  $Id: udp_snoop.c,v 1.1 2006/09/07 11:44:42 debug Exp $
 *
 *  Dumps UDP packets in hex and ASCII that arrive at a specific port.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>


void dump_buf(unsigned char *p, ssize_t len)
{
        while (len > 0) {
                ssize_t i, n = len>=16? 16 : len;
                for (i=0; i<n; i++)
                        printf(" %02x", p[i]);
                for (i=n; i<16; i++)
                        printf("   ");
                printf("  ");
                for (i=0; i<n; i++) {
                        if (p[i]>=32 && p[i]<127)
                                printf("%c", p[i]);
                        else
                                printf(".");
                }
                printf("\n");
                p += 16;
                len -= 16;
        }
}


int main(int argc, char *argv[])
{
        struct sockaddr_in si;
        int s;

        if (argc < 2) {
                fprintf(stderr, "usage: %s udp_portnr\n", argv[0]);
                exit(1);
        }

        if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
                perror("socket");
                exit(1);
        }

        memset((char *)&si, sizeof(si), 0);
        si.sin_family = AF_INET;
        si.sin_port = htons(atoi(argv[1]));
        si.sin_addr.s_addr = htonl(INADDR_ANY);
        if (bind(s, (struct sockaddr *)&si, sizeof(si)) < 0) {
                perror("bind");
                exit(1);
        }

        for (;;) {
                unsigned char buf[2048];
                ssize_t r = recv(s, buf, sizeof(buf), 0);

                if (r < 0) {
                        perror("recv");
                        exit(1);
                }

                dump_buf(buf, r);
                printf("\n");
        }

        return 0;
}

1	/*
2	* Copyright (C) 2006 Anders Gavare. All rights reserved.
3	*
4	* Redistribution and use in source and binary forms, with or without
5	* modification, are permitted provided that the following conditions are met:
6	*
7	* 1. Redistributions of source code must retain the above copyright
8	* notice, this list of conditions and the following disclaimer.
9	* 2. Redistributions in binary form must reproduce the above copyright
10	* notice, this list of conditions and the following disclaimer in the
11	* documentation and/or other materials provided with the distribution.
12	* 3. The name of the author may not be used to endorse or promote products
13	* derived from this software without specific prior written permission.
14	*
15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25	* SUCH DAMAGE.
26	*
27	*
28	* $Id: udp_snoop.c,v 1.1 2006/09/07 11:44:42 debug Exp $
29	*
30	* Dumps UDP packets in hex and ASCII that arrive at a specific port.
31	*/
32
33	#include <stdio.h>
34	#include <stdlib.h>
35	#include <sys/types.h>
36	#include <sys/socket.h>
37	#include <netinet/in.h>
38
39
40	void dump_buf(unsigned char *p, ssize_t len)
41	{
42	while (len > 0) {
43	ssize_t i, n = len>=16? 16 : len;
44	for (i=0; i<n; i++)
45	printf(" %02x", p[i]);
46	for (i=n; i<16; i++)
47	printf(" ");
48	printf(" ");
49	for (i=0; i<n; i++) {
50	if (p[i]>=32 && p[i]<127)
51	printf("%c", p[i]);
52	else
53	printf(".");
54	}
55	printf("\n");
56	p += 16;
57	len -= 16;
58	}
59	}
60
61
62	int main(int argc, char *argv[])
63	{
64	struct sockaddr_in si;
65	int s;
66
67	if (argc < 2) {
68	fprintf(stderr, "usage: %s udp_portnr\n", argv[0]);
69	exit(1);
70	}
71
72	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
73	perror("socket");
74	exit(1);
75	}
76
77	memset((char *)&si, sizeof(si), 0);
78	si.sin_family = AF_INET;
79	si.sin_port = htons(atoi(argv[1]));
80	si.sin_addr.s_addr = htonl(INADDR_ANY);
81	if (bind(s, (struct sockaddr *)&si, sizeof(si)) < 0) {
82	perror("bind");
83	exit(1);
84	}
85
86	for (;;) {
87	unsigned char buf[2048];
88	ssize_t r = recv(s, buf, sizeof(buf), 0);
89
90	if (r < 0) {
91	perror("recv");
92	exit(1);
93	}
94
95	dump_buf(buf, r);
96	printf("\n");
97	}
98
99	return 0;
100	}
101