void
gre_print_0(const u_char *bp, u_int length)
{
u_int len = length;
u_int16_t flags, prot;
flags = EXTRACT_16BITS(bp);
if (vflag)
printf(", Flags [%s]",
bittok2str(gre_flag_values,"none",flags));
len -= 2;
bp += 2;
if (len < 2)
goto trunc;
prot = EXTRACT_16BITS(bp);
len -= 2;
bp += 2;
if ((flags & GRE_CP) | (flags & GRE_RP)) {
if (len < 2)
goto trunc;
if (vflag)
printf(", sum 0x%x", EXTRACT_16BITS(bp));
bp += 2;
len -= 2;
if (len < 2)
goto trunc;
printf(", off 0x%x", EXTRACT_16BITS(bp));
bp += 2;
len -= 2;
}
if (flags & GRE_KP) {
if (len < 4)
goto trunc;
printf(", key=0x%x", EXTRACT_32BITS(bp));
bp += 4;
len -= 4;
}
if (flags & GRE_SP) {
if (len < 4)
goto trunc;
printf(", seq %u", EXTRACT_32BITS(bp));
bp += 4;
len -= 4;
}
if (flags & GRE_RP) {
for (;;) {
u_int16_t af;
u_int8_t sreoff;
u_int8_t srelen;
if (len < 4)
goto trunc;
af = EXTRACT_16BITS(bp);
sreoff = *(bp + 2);
srelen = *(bp + 3);
bp += 4;
len -= 4;
if (af == 0 && srelen == 0)
break;
gre_sre_print(af, sreoff, srelen, bp, len);
if (len < srelen)
goto trunc;
bp += srelen;
len -= srelen;
}
}
if (eflag)
printf(", proto %s (0x%04x)",
tok2str(ethertype_values,"unknown",prot),
prot);
printf(", length %u",length);
if (vflag < 1)
printf(": "); /* put in a colon as protocol demarc */
else
printf("\n\t"); /* if verbose go multiline */
switch (prot) {
case ETHERTYPE_IP:
ip_print(gndo, bp, len);
break;
#ifdef INET6
case ETHERTYPE_IPV6:
ip6_print(gndo, bp, len);
break;
#endif
case ETHERTYPE_MPLS:
mpls_print(bp, len);
break;
case ETHERTYPE_IPX:
ipx_print(bp, len);
break;
case ETHERTYPE_ATALK:
atalk_print(bp, len);
break;
case ETHERTYPE_GRE_ISO:
isoclns_print(bp, len, len);
break;
case ETHERTYPE_TEB:
ether_print(gndo, bp, len, len, NULL, NULL);
break;
default:
printf("gre-proto-0x%x", prot);
}
return;
trunc:
printf("[|gre]");
}
static void
gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
{
u_int len = length;
uint16_t flags, prot;
/* 16 bits ND_TCHECKed in gre_print() */
flags = EXTRACT_BE_U_2(bp);
if (ndo->ndo_vflag)
ND_PRINT(", Flags [%s]",
bittok2str(gre_flag_values,"none",flags));
len -= 2;
bp += 2;
ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
prot = EXTRACT_BE_U_2(bp);
len -= 2;
bp += 2;
if ((flags & GRE_CP) | (flags & GRE_RP)) {
ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
if (ndo->ndo_vflag)
ND_PRINT(", sum 0x%x", EXTRACT_BE_U_2(bp));
bp += 2;
len -= 2;
ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
ND_PRINT(", off 0x%x", EXTRACT_BE_U_2(bp));
bp += 2;
len -= 2;
}
if (flags & GRE_KP) {
ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
ND_PRINT(", key=0x%x", EXTRACT_BE_U_4(bp));
bp += 4;
len -= 4;
}
if (flags & GRE_SP) {
ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
ND_PRINT(", seq %u", EXTRACT_BE_U_4(bp));
bp += 4;
len -= 4;
}
if (flags & GRE_RP) {
for (;;) {
uint16_t af;
uint8_t sreoff;
uint8_t srelen;
ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
af = EXTRACT_BE_U_2(bp);
sreoff = EXTRACT_U_1(bp + 2);
srelen = EXTRACT_U_1(bp + 3);
bp += 4;
len -= 4;
if (af == 0 && srelen == 0)
break;
if (!gre_sre_print(ndo, af, sreoff, srelen, bp, len))
goto trunc;
if (len < srelen)
goto trunc;
bp += srelen;
len -= srelen;
}
}
if (ndo->ndo_eflag)
ND_PRINT(", proto %s (0x%04x)",
tok2str(ethertype_values,"unknown",prot),
prot);
ND_PRINT(", length %u",length);
if (ndo->ndo_vflag < 1)
ND_PRINT(": "); /* put in a colon as protocol demarc */
else
ND_PRINT("\n\t"); /* if verbose go multiline */
switch (prot) {
case ETHERTYPE_IP:
ip_print(ndo, bp, len);
break;
case ETHERTYPE_IPV6:
ip6_print(ndo, bp, len);
break;
case ETHERTYPE_MPLS:
mpls_print(ndo, bp, len);
break;
case ETHERTYPE_IPX:
ipx_print(ndo, bp, len);
break;
case ETHERTYPE_ATALK:
atalk_print(ndo, bp, len);
break;
case ETHERTYPE_GRE_ISO:
isoclns_print(ndo, bp, len);
break;
case ETHERTYPE_TEB:
ether_print(ndo, bp, len, ndo->ndo_snapend - bp, NULL, NULL);
break;
default:
ND_PRINT("gre-proto-0x%x", prot);
}
return;
trunc:
ND_PRINT("%s", tstr);
}
