print-udp.c

来自「TCPDUMP的C语言源代码,是在数据链路层的应用」· C语言 代码 · 共 716 行 · 第 1/2 页

/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/print-udp.c,v 1.142 2007-08-08 17:20:58 hannes Exp $ (LBL)";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <tcpdump-stdinc.h>

#ifdef SEGSIZE
#undef SEGSIZE
#endif
#include <arpa/tftp.h>

#include <stdio.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"
#include "extract.h"
#include "appletalk.h"

#include "udp.h"

#include "ip.h"
#ifdef INET6
#include "ip6.h"
#endif
#include "ipproto.h"
#include "rpc_auth.h"
#include "rpc_msg.h"

#include "nameser.h"
#include "nfs.h"
#include "bootp.h"

struct rtcphdr {
	u_int16_t rh_flags;	/* T:2 P:1 CNT:5 PT:8 */
	u_int16_t rh_len;	/* length of message (in words) */
	u_int32_t rh_ssrc;	/* synchronization src id */
};

typedef struct {
	u_int32_t upper;	/* more significant 32 bits */
	u_int32_t lower;	/* less significant 32 bits */
} ntp64;

/*
 * Sender report.
 */
struct rtcp_sr {
	ntp64 sr_ntp;		/* 64-bit ntp timestamp */
	u_int32_t sr_ts;	/* reference media timestamp */
	u_int32_t sr_np;	/* no. packets sent */
	u_int32_t sr_nb;	/* no. bytes sent */
};

/*
 * Receiver report.
 * Time stamps are middle 32-bits of ntp timestamp.
 */
struct rtcp_rr {
	u_int32_t rr_srcid;	/* sender being reported */
	u_int32_t rr_nl;	/* no. packets lost */
	u_int32_t rr_ls;	/* extended last seq number received */
	u_int32_t rr_dv;	/* jitter (delay variance) */
	u_int32_t rr_lsr;	/* orig. ts from last rr from this src  */
	u_int32_t rr_dlsr;	/* time from recpt of last rr to xmit time */
};

/*XXX*/
#define RTCP_PT_SR	200
#define RTCP_PT_RR	201
#define RTCP_PT_SDES	202
#define 	RTCP_SDES_CNAME	1
#define 	RTCP_SDES_NAME	2
#define 	RTCP_SDES_EMAIL	3
#define 	RTCP_SDES_PHONE	4
#define 	RTCP_SDES_LOC	5
#define 	RTCP_SDES_TOOL	6
#define 	RTCP_SDES_NOTE	7
#define 	RTCP_SDES_PRIV	8
#define RTCP_PT_BYE	203
#define RTCP_PT_APP	204

static void
vat_print(const void *hdr, register const struct udphdr *up)
{
	/* vat/vt audio */
	u_int ts = *(u_int16_t *)hdr;
	if ((ts & 0xf060) != 0) {
		/* probably vt */
		(void)printf("udp/vt %u %d / %d",
			     (u_int32_t)(EXTRACT_16BITS(&up->uh_ulen) - sizeof(*up)),
			     ts & 0x3ff, ts >> 10);
	} else {
		/* probably vat */
		u_int32_t i0 = EXTRACT_32BITS(&((u_int *)hdr)[0]);
		u_int32_t i1 = EXTRACT_32BITS(&((u_int *)hdr)[1]);
		printf("udp/vat %u c%d %u%s",
			(u_int32_t)(EXTRACT_16BITS(&up->uh_ulen) - sizeof(*up) - 8),
			i0 & 0xffff,
			i1, i0 & 0x800000? "*" : "");
		/* audio format */
		if (i0 & 0x1f0000)
			printf(" f%d", (i0 >> 16) & 0x1f);
		if (i0 & 0x3f000000)
			printf(" s%d", (i0 >> 24) & 0x3f);
	}
}

static void
rtp_print(const void *hdr, u_int len, register const struct udphdr *up)
{
	/* rtp v1 or v2 */
	u_int *ip = (u_int *)hdr;
	u_int hasopt, hasext, contype, hasmarker;
	u_int32_t i0 = EXTRACT_32BITS(&((u_int *)hdr)[0]);
	u_int32_t i1 = EXTRACT_32BITS(&((u_int *)hdr)[1]);
	u_int dlen = EXTRACT_16BITS(&up->uh_ulen) - sizeof(*up) - 8;
	const char * ptype;

	ip += 2;
	len >>= 2;
	len -= 2;
	hasopt = 0;
	hasext = 0;
	if ((i0 >> 30) == 1) {
		/* rtp v1 */
		hasopt = i0 & 0x800000;
		contype = (i0 >> 16) & 0x3f;
		hasmarker = i0 & 0x400000;
		ptype = "rtpv1";
	} else {
		/* rtp v2 */
		hasext = i0 & 0x10000000;
		contype = (i0 >> 16) & 0x7f;
		hasmarker = i0 & 0x800000;
		dlen -= 4;
		ptype = "rtp";
		ip += 1;
		len -= 1;
	}
	printf("udp/%s %d c%d %s%s %d %u",
		ptype,
		dlen,
		contype,
		(hasopt || hasext)? "+" : "",
		hasmarker? "*" : "",
		i0 & 0xffff,
		i1);
	if (vflag) {
		printf(" %u", EXTRACT_32BITS(&((u_int *)hdr)[2]));
		if (hasopt) {
			u_int i2, optlen;
			do {
				i2 = ip[0];
				optlen = (i2 >> 16) & 0xff;
				if (optlen == 0 || optlen > len) {
					printf(" !opt");
					return;
				}
				ip += optlen;
				len -= optlen;
			} while ((int)i2 >= 0);
		}
		if (hasext) {
			u_int i2, extlen;
			i2 = ip[0];
			extlen = (i2 & 0xffff) + 1;
			if (extlen > len) {
				printf(" !ext");
				return;
			}
			ip += extlen;
		}
		if (contype == 0x1f) /*XXX H.261 */
			printf(" 0x%04x", ip[0] >> 16);
	}
}

static const u_char *
rtcp_print(const u_char *hdr, const u_char *ep)
{
	/* rtp v2 control (rtcp) */
	struct rtcp_rr *rr = 0;
	struct rtcp_sr *sr;
	struct rtcphdr *rh = (struct rtcphdr *)hdr;
	u_int len;
	u_int16_t flags;
	int cnt;
	double ts, dts;
	if ((u_char *)(rh + 1) > ep) {
		printf(" [|rtcp]");
		return (ep);
	}
	len = (EXTRACT_16BITS(&rh->rh_len) + 1) * 4;
	flags = EXTRACT_16BITS(&rh->rh_flags);
	cnt = (flags >> 8) & 0x1f;
	switch (flags & 0xff) {
	case RTCP_PT_SR:
		sr = (struct rtcp_sr *)(rh + 1);
		printf(" sr");
		if (len != cnt * sizeof(*rr) + sizeof(*sr) + sizeof(*rh))
			printf(" [%d]", len);
		if (vflag)
			printf(" %u", EXTRACT_32BITS(&rh->rh_ssrc));
		if ((u_char *)(sr + 1) > ep) {
			printf(" [|rtcp]");
			return (ep);
		}
		ts = (double)(EXTRACT_32BITS(&sr->sr_ntp.upper)) +
		    ((double)(EXTRACT_32BITS(&sr->sr_ntp.lower)) /
		    4294967296.0);
		printf(" @%.2f %u %up %ub", ts, EXTRACT_32BITS(&sr->sr_ts),
		    EXTRACT_32BITS(&sr->sr_np), EXTRACT_32BITS(&sr->sr_nb));
		rr = (struct rtcp_rr *)(sr + 1);
		break;
	case RTCP_PT_RR:
		printf(" rr");
		if (len != cnt * sizeof(*rr) + sizeof(*rh))
			printf(" [%d]", len);
		rr = (struct rtcp_rr *)(rh + 1);
		if (vflag)
			printf(" %u", EXTRACT_32BITS(&rh->rh_ssrc));
		break;
	case RTCP_PT_SDES:
		printf(" sdes %d", len);
		if (vflag)
			printf(" %u", EXTRACT_32BITS(&rh->rh_ssrc));
		cnt = 0;
		break;
	case RTCP_PT_BYE:
		printf(" bye %d", len);
		if (vflag)
			printf(" %u", EXTRACT_32BITS(&rh->rh_ssrc));
		cnt = 0;
		break;
	default:
		printf(" type-0x%x %d", flags & 0xff, len);
		cnt = 0;
		break;
	}
	if (cnt > 1)
		printf(" c%d", cnt);
	while (--cnt >= 0) {
		if ((u_char *)(rr + 1) > ep) {
			printf(" [|rtcp]");
			return (ep);
		}
		if (vflag)
			printf(" %u", EXTRACT_32BITS(&rr->rr_srcid));
		ts = (double)(EXTRACT_32BITS(&rr->rr_lsr)) / 65536.;
		dts = (double)(EXTRACT_32BITS(&rr->rr_dlsr)) / 65536.;
		printf(" %ul %us %uj @%.2f+%.2f",
		    EXTRACT_32BITS(&rr->rr_nl) & 0x00ffffff,
		    EXTRACT_32BITS(&rr->rr_ls),
		    EXTRACT_32BITS(&rr->rr_dv), ts, dts);
	}
	return (hdr + len);
}

static int udp_cksum(register const struct ip *ip,
		     register const struct udphdr *up,
		     register u_int len)
{
	union phu {
		struct phdr {
			u_int32_t src;
			u_int32_t dst;
			u_char mbz;
			u_char proto;
			u_int16_t len;
		} ph;
		u_int16_t pa[6];
	} phu;
	register const u_int16_t *sp;

	/* pseudo-header.. */
	phu.ph.len = htons((u_int16_t)len);
	phu.ph.mbz = 0;
	phu.ph.proto = IPPROTO_UDP;
	memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
	if (IP_HL(ip) == 5)
		memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
	else
		phu.ph.dst = ip_finddst(ip);

	sp = &phu.pa[0];
	return in_cksum((u_short *)up, len,
			sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
}

#ifdef INET6
static int udp6_cksum(const struct ip6_hdr *ip6, const struct udphdr *up,
	u_int len)
{
	size_t i;
	register const u_int16_t *sp;
	u_int32_t sum;
	union {
		struct {
			struct in6_addr ph_src;
			struct in6_addr ph_dst;
			u_int32_t	ph_len;
			u_int8_t	ph_zero[3];
			u_int8_t	ph_nxt;
		} ph;
		u_int16_t pa[20];
	} phu;

	/* pseudo-header */
	memset(&phu, 0, sizeof(phu));
	phu.ph.ph_src = ip6->ip6_src;
	phu.ph.ph_dst = ip6->ip6_dst;
	phu.ph.ph_len = htonl(len);
	phu.ph.ph_nxt = IPPROTO_UDP;

	sum = 0;
	for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
		sum += phu.pa[i];

	sp = (const u_int16_t *)up;

	for (i = 0; i < (len & ~1); i += 2)
		sum += *sp++;

	if (len & 1)
		sum += htons((*(const u_int8_t *)sp) << 8);

	while (sum > 0xffff)
		sum = (sum & 0xffff) + (sum >> 16);
	sum = ~sum & 0xffff;

	return (sum);