print-pppoe.c

/*
 * 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[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-pppoe.c,v 1.3 1999-12-15 00:23:06 fenner Exp $ (LBL)";
#endif

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

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>

#if __STDC__
struct mbuf;
struct rtentry;
#endif
#include <net/if.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#include <stdio.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"
#include "ppp.h"
#include "ethertype.h"
#include "extract.h"			/* must come after interface.h */

/* Codes */
enum { 
  PPPOE_PADI = 0x09,
  PPPOE_PADO = 0x07,
  PPPOE_PADR = 0x19,
  PPPOE_PADS = 0x65,
  PPPOE_PADT = 0xa7
};

static struct tok pppoecode2str[] = {
  { PPPOE_PADI, "PADI"},
  { PPPOE_PADO, "PADO"},
  { PPPOE_PADR, "PADR"},
  { PPPOE_PADS, "PADS"},
  { PPPOE_PADT, "PADT"},
  { 0, ""}, /* PPP Data */
  { 0, NULL }
};

/* Tags */
enum {
  PPPOE_EOL = 0,
  PPPOE_SERVICE_NAME = 0x0101,
  PPPOE_AC_NAME = 0x0102,
  PPPOE_HOST_UNIQ = 0x0103,
  PPPOE_AC_COOKIE = 0x0104,
  PPPOE_VENDOR = 0x0105,
  PPPOE_RELAY_SID = 0x0110,
  PPPOE_SERVICE_NAME_ERROR = 0x0201,
  PPPOE_AC_SYSTEM_ERROR = 0x0202,
  PPPOE_GENERIC_ERROR = 0x0203,
};

static struct tok pppoetag2str[] = {
  { PPPOE_EOL, "EOL"},
  { PPPOE_SERVICE_NAME, "Service-Name" },
  { PPPOE_AC_NAME, "AC-Name" },
  { PPPOE_HOST_UNIQ, "Host-Uniq" },
  { PPPOE_AC_COOKIE, "AC-Cookie" },
  { PPPOE_VENDOR, "Vendor-Specific" },
  { PPPOE_RELAY_SID, "Relay-Session-ID" },
  { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
  { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
  { PPPOE_GENERIC_ERROR, "Generic-Error" },
  { 0, NULL}
};

#define PPPOE_HDRLEN 6

void
pppoe_print(register const u_char *bp, u_int length)
{
  register const struct ether_header *eh;
  register u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length;
  const u_char *pppoe_packet, *pppoe_payload;

  eh = (struct ether_header *)packetp;
  pppoe_packet = packetp+sizeof(struct ether_header);
  if (pppoe_packet > snapend) {
    printf("[|pppoe]");
    return;
  }

  pppoe_ver  = (pppoe_packet[0]&0xF0)>>4;
  pppoe_type  = (pppoe_packet[0]&0x0F);
  pppoe_code = (pppoe_packet[1]);
  pppoe_sessionid = (EXTRACT_16BITS(pppoe_packet+2));
  pppoe_length    = (EXTRACT_16BITS(pppoe_packet+4));
  pppoe_payload = pppoe_packet+6;
	
  if (snapend < pppoe_payload) {
    printf(" truncated PPPoE");
    return;
  }
	
  if (pppoe_ver != 1) {
    printf(" [ver %d]",pppoe_ver);
  }
  if (pppoe_type != 1) {
    printf(" [type %d]",pppoe_type);
  }
	
  printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
  if (pppoe_code == PPPOE_PADI && pppoe_length > 1484-PPPOE_HDRLEN) {
    printf(" [len %d!]",pppoe_length);
  }
  if (pppoe_sessionid) {
    printf(" [ses 0x%x]",pppoe_sessionid);
  }

  if (pppoe_payload + pppoe_length < snapend) {
    /*
    printf(" [length %d (%d extra bytes)]", pppoe_length, snapend-pppoe_payload-pppoe_length);
    {
      const u_char *x = pppoe_payload+pppoe_length;
      default_print(x, snapend - x);
    }
    */
    snapend = pppoe_payload+pppoe_length;
  }

  
  if (pppoe_code) {
    /* PPP session packets don't contain tags */
    u_short tag_type = -1, tag_len;
    const u_char *p = pppoe_payload;

    /* loop invariant: 
       p points to next tag, 
       tag_type is previous tag or -1 for first iteration 
    */
    while (tag_type && 
	   p+4 < pppoe_payload + length && 
	   p+4 < snapend) {
      tag_type = EXTRACT_16BITS(p);
      tag_len  = EXTRACT_16BITS(p+2);
      p += 4;
      /* p points to tag_value */

      if (tag_len) {
	int isascii = 1;
	const u_char *v = p;

	for (v=p; v<p+tag_len; v++) 
	  if (*v >= 127 || *v < 32) {
	    isascii = 0;
	    break;
	  }
	
	/* TODO print UTF8 decoded text */
	if (isascii) 
	  printf(" [%s \"%*.*s\"]",
		 tok2str(pppoetag2str, "TAG-0x%x", tag_type),
		 tag_len < 80 ? tag_len : 80,
		 tag_len < 80 ? tag_len : 80,
		 p
		 );
	else 
	  printf(" [%s UTF8]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
      } else
	printf(" [%s]", tok2str(pppoetag2str, "TAG-0x%x", tag_type));
      
      p += tag_len;
      /* p points to next tag */
    }
  } else {
    u_short ptype;
    if (pppoe_payload[0] & 0x1) {
      ptype = pppoe_payload[0];
      pppoe_payload +=1;
      pppoe_length  -=1;
    } else if (pppoe_payload[1] & 0x1) {
      ptype = ntohs(*(u_short *)pppoe_payload);
      pppoe_payload +=2;
      pppoe_length  -=2;
    } else {
      printf(" Invalid PPP protocol ID: %x %x", pppoe_payload[0],pppoe_payload[1]);
      return;
    }
    printf(" ");
    if (ptype == PPP_IP)
      ip_print(pppoe_payload, pppoe_length);
    else if (ptype == PPP_LCP) 
      lcp_print(pppoe_payload, pppoe_length);
    else
      printf("%s ", tok2str(ppptype2str, "proto-0x%x", ptype));
  }
  return;
}