addrtoname.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 1,183 行 · 第 1/2 页

/*
 * Copyright (c) 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.
 *
 *  Internet, ethernet, port, and protocol string to address
 *  and address to string conversion routines
 */
#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/tcpdump/addrtoname.c,v 1.119 2007-08-08 14:06:34 hannes Exp $ (LBL)";
#endif

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

#include <tcpdump-stdinc.h>

#ifdef USE_ETHER_NTOHOST
#ifdef HAVE_NETINET_IF_ETHER_H
struct mbuf;		/* Squelch compiler warnings on some platforms for */
struct rtentry;		/* declarations in <net/if.h> */
#include <net/if.h>	/* for "struct ifnet" in "struct arpcom" on Solaris */
#include <netinet/if_ether.h>
#endif /* HAVE_NETINET_IF_ETHER_H */
#ifdef NETINET_ETHER_H_DECLARES_ETHER_NTOHOST
#include <netinet/ether.h>
#endif /* NETINET_ETHER_H_DECLARES_ETHER_NTOHOST */

#if !defined(HAVE_DECL_ETHER_NTOHOST) || !HAVE_DECL_ETHER_NTOHOST
#ifndef HAVE_STRUCT_ETHER_ADDR
struct ether_addr {
	unsigned char ether_addr_octet[6];
};
#endif
extern int ether_ntohost(char *, const struct ether_addr *);
#endif

#endif /* USE_ETHER_NTOHOST */

#include <pcap.h>
#include <pcap-namedb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "interface.h"
#include "addrtoname.h"
#include "llc.h"
#include "setsignal.h"
#include "extract.h"
#include "oui.h"

#ifndef ETHER_ADDR_LEN
#define ETHER_ADDR_LEN	6
#endif

/*
 * hash tables for whatever-to-name translations
 *
 * XXX there has to be error checks against strdup(3) failure
 */

#define HASHNAMESIZE 4096

struct hnamemem {
	u_int32_t addr;
	const char *name;
	struct hnamemem *nxt;
};

struct hnamemem hnametable[HASHNAMESIZE];
struct hnamemem tporttable[HASHNAMESIZE];
struct hnamemem uporttable[HASHNAMESIZE];
struct hnamemem eprototable[HASHNAMESIZE];
struct hnamemem dnaddrtable[HASHNAMESIZE];
struct hnamemem ipxsaptable[HASHNAMESIZE];

#if defined(INET6) && defined(WIN32)
/*
 * fake gethostbyaddr for Win2k/XP
 * gethostbyaddr() returns incorrect value when AF_INET6 is passed
 * to 3rd argument.
 *
 * h_name in struct hostent is only valid.
 */
static struct hostent *
win32_gethostbyaddr(const char *addr, int len, int type)
{
	static struct hostent host;
	static char hostbuf[NI_MAXHOST];
	char hname[NI_MAXHOST];
	struct sockaddr_in6 addr6;

	host.h_name = hostbuf;
	switch (type) {
	case AF_INET:
		return gethostbyaddr(addr, len, type);
		break;
	case AF_INET6:
		memset(&addr6, 0, sizeof(addr6));
		addr6.sin6_family = AF_INET6;
		memcpy(&addr6.sin6_addr, addr, len);
		if (getnameinfo((struct sockaddr *)&addr6, sizeof(addr6),
		    hname, sizeof(hname), NULL, 0, 0)) {
			return NULL;
		} else {
			strcpy(host.h_name, hname);
			return &host;
		}
		break;
	default:
		return NULL;
	}
}
#define gethostbyaddr win32_gethostbyaddr
#endif /* INET6 & WIN32 */

#ifdef INET6
struct h6namemem {
	struct in6_addr addr;
	char *name;
	struct h6namemem *nxt;
};

struct h6namemem h6nametable[HASHNAMESIZE];
#endif /* INET6 */

struct enamemem {
	u_short e_addr0;
	u_short e_addr1;
	u_short e_addr2;
	const char *e_name;
	u_char *e_nsap;			/* used only for nsaptable[] */
#define e_bs e_nsap			/* for bytestringtable */
	struct enamemem *e_nxt;
};

struct enamemem enametable[HASHNAMESIZE];
struct enamemem nsaptable[HASHNAMESIZE];
struct enamemem bytestringtable[HASHNAMESIZE];

struct protoidmem {
	u_int32_t p_oui;
	u_short p_proto;
	const char *p_name;
	struct protoidmem *p_nxt;
};

struct protoidmem protoidtable[HASHNAMESIZE];

/*
 * A faster replacement for inet_ntoa().
 */
const char *
intoa(u_int32_t addr)
{
	register char *cp;
	register u_int byte;
	register int n;
	static char buf[sizeof(".xxx.xxx.xxx.xxx")];

	NTOHL(addr);
	cp = buf + sizeof(buf);
	*--cp = '\0';

	n = 4;
	do {
		byte = addr & 0xff;
		*--cp = byte % 10 + '0';
		byte /= 10;
		if (byte > 0) {
			*--cp = byte % 10 + '0';
			byte /= 10;
			if (byte > 0)
				*--cp = byte + '0';
		}
		*--cp = '.';
		addr >>= 8;
	} while (--n > 0);

	return cp + 1;
}

static u_int32_t f_netmask;
static u_int32_t f_localnet;

/*
 * Return a name for the IP address pointed to by ap.  This address
 * is assumed to be in network byte order.
 *
 * NOTE: ap is *NOT* necessarily part of the packet data (not even if
 * this is being called with the "ipaddr_string()" macro), so you
 * *CANNOT* use the TCHECK{2}/TTEST{2} macros on it.  Furthermore,
 * even in cases where it *is* part of the packet data, the caller
 * would still have to check for a null return value, even if it's
 * just printing the return value with "%s" - not all versions of
 * printf print "(null)" with "%s" and a null pointer, some of them
 * don't check for a null pointer and crash in that case.
 *
 * The callers of this routine should, before handing this routine
 * a pointer to packet data, be sure that the data is present in
 * the packet buffer.  They should probably do those checks anyway,
 * as other data at that layer might not be IP addresses, and it
 * also needs to check whether they're present in the packet buffer.
 */
const char *
getname(const u_char *ap)
{
	register struct hostent *hp;
	u_int32_t addr;
	static struct hnamemem *p;		/* static for longjmp() */

	memcpy(&addr, ap, sizeof(addr));
	p = &hnametable[addr & (HASHNAMESIZE-1)];
	for (; p->nxt; p = p->nxt) {
		if (p->addr == addr)
			return (p->name);
	}
	p->addr = addr;
	p->nxt = newhnamemem();

	/*
	 * Print names unless:
	 *	(1) -n was given.
	 *      (2) Address is foreign and -f was given. (If -f was not
	 *	    given, f_netmask and f_localnet are 0 and the test
	 *	    evaluates to true)
	 */
	if (!nflag &&
	    (addr & f_netmask) == f_localnet) {
		hp = gethostbyaddr((char *)&addr, 4, AF_INET);
		if (hp) {
			char *dotp;

			p->name = strdup(hp->h_name);
			if (Nflag) {
				/* Remove domain qualifications */
				dotp = strchr(p->name, '.');
				if (dotp)
					*dotp = '\0';
			}
			return (p->name);
		}
	}
	p->name = strdup(intoa(addr));
	return (p->name);
}

#ifdef INET6
/*
 * Return a name for the IP6 address pointed to by ap.  This address
 * is assumed to be in network byte order.
 */
const char *
getname6(const u_char *ap)
{
	register struct hostent *hp;
	struct in6_addr addr;
	static struct h6namemem *p;		/* static for longjmp() */
	register const char *cp;
	char ntop_buf[INET6_ADDRSTRLEN];

	memcpy(&addr, ap, sizeof(addr));
	p = &h6nametable[*(u_int16_t *)&addr.s6_addr[14] & (HASHNAMESIZE-1)];
	for (; p->nxt; p = p->nxt) {
		if (memcmp(&p->addr, &addr, sizeof(addr)) == 0)
			return (p->name);
	}
	p->addr = addr;
	p->nxt = newh6namemem();

	/*
	 * Do not print names if -n was given.
	 */
	if (!nflag) {
		hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET6);
		if (hp) {
			char *dotp;

			p->name = strdup(hp->h_name);
			if (Nflag) {
				/* Remove domain qualifications */
				dotp = strchr(p->name, '.');
				if (dotp)
					*dotp = '\0';
			}
			return (p->name);
		}
	}
	cp = inet_ntop(AF_INET6, &addr, ntop_buf, sizeof(ntop_buf));
	p->name = strdup(cp);
	return (p->name);
}
#endif /* INET6 */

static char hex[] = "0123456789abcdef";


/* Find the hash node that corresponds the ether address 'ep' */

static inline struct enamemem *
lookup_emem(const u_char *ep)
{
	register u_int i, j, k;
	struct enamemem *tp;

	k = (ep[0] << 8) | ep[1];
	j = (ep[2] << 8) | ep[3];
	i = (ep[4] << 8) | ep[5];

	tp = &enametable[(i ^ j) & (HASHNAMESIZE-1)];
	while (tp->e_nxt)
		if (tp->e_addr0 == i &&
		    tp->e_addr1 == j &&
		    tp->e_addr2 == k)
			return tp;
		else
			tp = tp->e_nxt;
	tp->e_addr0 = i;
	tp->e_addr1 = j;
	tp->e_addr2 = k;
	tp->e_nxt = (struct enamemem *)calloc(1, sizeof(*tp));
	if (tp->e_nxt == NULL)
		error("lookup_emem: calloc");

	return tp;
}

/*
 * Find the hash node that corresponds to the bytestring 'bs'
 * with length 'nlen'
 */

static inline struct enamemem *
lookup_bytestring(register const u_char *bs, const unsigned int nlen)
{
	struct enamemem *tp;
	register u_int i, j, k;

	if (nlen >= 6) {
		k = (bs[0] << 8) | bs[1];
		j = (bs[2] << 8) | bs[3];
		i = (bs[4] << 8) | bs[5];
	} else if (nlen >= 4) {
		k = (bs[0] << 8) | bs[1];
		j = (bs[2] << 8) | bs[3];
		i = 0;
	} else
		i = j = k = 0;

	tp = &bytestringtable[(i ^ j) & (HASHNAMESIZE-1)];
	while (tp->e_nxt)
		if (tp->e_addr0 == i &&
		    tp->e_addr1 == j &&
		    tp->e_addr2 == k &&
		    memcmp((const char *)bs, (const char *)(tp->e_bs), nlen) == 0)
			return tp;
		else
			tp = tp->e_nxt;

	tp->e_addr0 = i;
	tp->e_addr1 = j;
	tp->e_addr2 = k;

	tp->e_bs = (u_char *) calloc(1, nlen + 1);
	memcpy(tp->e_bs, bs, nlen);
	tp->e_nxt = (struct enamemem *)calloc(1, sizeof(*tp));
	if (tp->e_nxt == NULL)
		error("lookup_bytestring: calloc");

	return tp;
}

/* Find the hash node that corresponds the NSAP 'nsap' */

static inline struct enamemem *
lookup_nsap(register const u_char *nsap)
{
	register u_int i, j, k;
	unsigned int nlen = *nsap;
	struct enamemem *tp;
	const u_char *ensap = nsap + nlen - 6;

	if (nlen > 6) {
		k = (ensap[0] << 8) | ensap[1];
		j = (ensap[2] << 8) | ensap[3];
		i = (ensap[4] << 8) | ensap[5];
	}
	else
		i = j = k = 0;

	tp = &nsaptable[(i ^ j) & (HASHNAMESIZE-1)];
	while (tp->e_nxt)
		if (tp->e_addr0 == i &&
		    tp->e_addr1 == j &&
		    tp->e_addr2 == k &&
		    tp->e_nsap[0] == nlen &&
		    memcmp((const char *)&(nsap[1]),
			(char *)&(tp->e_nsap[1]), nlen) == 0)
			return tp;
		else
			tp = tp->e_nxt;
	tp->e_addr0 = i;
	tp->e_addr1 = j;
	tp->e_addr2 = k;
	tp->e_nsap = (u_char *)malloc(nlen + 1);
	if (tp->e_nsap == NULL)
		error("lookup_nsap: malloc");
	memcpy((char *)tp->e_nsap, (const char *)nsap, nlen + 1);
	tp->e_nxt = (struct enamemem *)calloc(1, sizeof(*tp));
	if (tp->e_nxt == NULL)
		error("lookup_nsap: calloc");

	return tp;
}

/* Find the hash node that corresponds the protoid 'pi'. */

static inline struct protoidmem *
lookup_protoid(const u_char *pi)
{
	register u_int i, j;
	struct protoidmem *tp;

	/* 5 octets won't be aligned */
	i = (((pi[0] << 8) + pi[1]) << 8) + pi[2];
	j =   (pi[3] << 8) + pi[4];
	/* XXX should be endian-insensitive, but do big-endian testing  XXX */

	tp = &protoidtable[(i ^ j) & (HASHNAMESIZE-1)];
	while (tp->p_nxt)
		if (tp->p_oui == i && tp->p_proto == j)
			return tp;
		else
			tp = tp->p_nxt;
	tp->p_oui = i;
	tp->p_proto = j;
	tp->p_nxt = (struct protoidmem *)calloc(1, sizeof(*tp));
	if (tp->p_nxt == NULL)
		error("lookup_protoid: calloc");

	return tp;
}

const char *
etheraddr_string(register const u_char *ep)
{
	register int i;
	register char *cp;
	register struct enamemem *tp;
	int oui;
	char buf[BUFSIZE];

	tp = lookup_emem(ep);
	if (tp->e_name)
		return (tp->e_name);
#ifdef USE_ETHER_NTOHOST
	if (!nflag) {
		char buf2[BUFSIZE];

		/*
		 * We don't cast it to "const struct ether_addr *"
		 * because some systems fail to declare the second
		 * argument as a "const" pointer, even though they
		 * don't modify what it points to.
		 */
		if (ether_ntohost(buf2, (struct ether_addr *)ep) == 0) {
			tp->e_name = strdup(buf2);
			return (tp->e_name);
		}
	}
#endif
	cp = buf;
	oui = EXTRACT_24BITS(ep);
	*cp++ = hex[*ep >> 4 ];
	*cp++ = hex[*ep++ & 0xf];
	for (i = 5; --i >= 0;) {
		*cp++ = ':';
		*cp++ = hex[*ep >> 4 ];
		*cp++ = hex[*ep++ & 0xf];
	}

	if (!nflag) {
		snprintf(cp, BUFSIZE - (2 + 5*3), " (oui %s)",
		    tok2str(oui_values, "Unknown", oui));
	} else
		*cp = '\0';
	tp->e_name = strdup(buf);
	return (tp->e_name);
}

const char *
linkaddr_string(const u_char *ep, const unsigned int type, const unsigned int len)
{
	register u_int i;
	register char *cp;
	register struct enamemem *tp;

	if (type == LINKADDR_ETHER && len == ETHER_ADDR_LEN) {
            return etheraddr_string(ep);
        }

        if (type == LINKADDR_FRELAY) {
            return q922_string(ep);
        }

	tp = lookup_bytestring(ep, len);
	if (tp->e_name)
		return (tp->e_name);

	tp->e_name = cp = (char *)malloc(len*3);
	if (tp->e_name == NULL)
		error("linkaddr_string: malloc");
	*cp++ = hex[*ep >> 4];
	*cp++ = hex[*ep++ & 0xf];
	for (i = len-1; i > 0 ; --i) {
		*cp++ = ':';
		*cp++ = hex[*ep >> 4];
		*cp++ = hex[*ep++ & 0xf];
	}
	*cp = '\0';
	return (tp->e_name);
}

const char *
etherproto_string(u_short port)
{
	register char *cp;
	register struct hnamemem *tp;
	register u_int32_t i = port;
	char buf[sizeof("0000")];

	for (tp = &eprototable[i & (HASHNAMESIZE-1)]; tp->nxt; tp = tp->nxt)
		if (tp->addr == i)
			return (tp->name);

	tp->addr = i;
	tp->nxt = newhnamemem();

	cp = buf;
	NTOHS(port);
	*cp++ = hex[port >> 12 & 0xf];
	*cp++ = hex[port >> 8 & 0xf];
	*cp++ = hex[port >> 4 & 0xf];
	*cp++ = hex[port & 0xf];
	*cp++ = '\0';
	tp->name = strdup(buf);
	return (tp->name);
}

const char *
protoid_string(register const u_char *pi)
{
	register u_int i, j;
	register char *cp;
	register struct protoidmem *tp;
	char buf[sizeof("00:00:00:00:00")];

	tp = lookup_protoid(pi);
	if (tp->p_name)
		return tp->p_name;

	cp = buf;
	if ((j = *pi >> 4) != 0)
		*cp++ = hex[j];
	*cp++ = hex[*pi++ & 0xf];
	for (i = 4; (int)--i >= 0;) {
		*cp++ = ':';
		if ((j = *pi >> 4) != 0)
			*cp++ = hex[j];
		*cp++ = hex[*pi++ & 0xf];
	}
	*cp = '\0';
	tp->p_name = strdup(buf);