+ if (len < 4)
+ goto trunc;
+ k = EXTRACT_32BITS(bp);
+ printf(", call %d", k & 0xffff);
+ len -= 4;
+ bp += 4;
+ }
+
+ if (flags & GRE_SP) {
+ if (len < 4)
+ goto trunc;
+ printf(", seq %u", EXTRACT_32BITS(bp));
+ bp += 4;
+ len -= 4;
+ }
+
+ if (flags & GRE_AP) {
+ if (len < 4)
+ goto trunc;
+ printf(", ack %u", EXTRACT_32BITS(bp));
+ bp += 4;
+ len -= 4;
+ }
+
+ if ((flags & GRE_SP) == 0)
+ printf(", no-payload");
+
+ if (eflag)
+ printf(", proto %s (0x%04x)",
+ tok2str(ethertype_values,"unknown",prot),
+ prot);
+
+ printf(", length %u",length);
+
+ if ((flags & GRE_SP) == 0)
+ return;
+
+ if (vflag < 1)
+ printf(": "); /* put in a colon as protocol demarc */
+ else
+ printf("\n\t"); /* if verbose go multiline */
+
+ switch (prot) {
+ case ETHERTYPE_PPP:
+ ppp_print(bp, len);
+ break;
+ default:
+ printf("gre-proto-0x%x", prot);
+ break;
+ }
+ return;
+
+trunc:
+ printf("[|gre]");
+}
+
+void
+gre_sre_print(u_int16_t af, u_int8_t sreoff, u_int8_t srelen,
+ const u_char *bp, u_int len)
+{
+ switch (af) {
+ case GRESRE_IP:
+ printf(", (rtaf=ip");
+ gre_sre_ip_print(sreoff, srelen, bp, len);
+ printf(") ");
+ break;
+ case GRESRE_ASN:
+ printf(", (rtaf=asn");
+ gre_sre_asn_print(sreoff, srelen, bp, len);
+ printf(") ");
+ break;
+ default:
+ printf(", (rtaf=0x%x) ", af);
+ }
+}
+void
+gre_sre_ip_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
+{
+ struct in_addr a;
+ const u_char *up = bp;
+
+ if (sreoff & 3) {
+ printf(", badoffset=%u", sreoff);
+ return;
+ }
+ if (srelen & 3) {
+ printf(", badlength=%u", srelen);
+ return;
+ }
+ if (sreoff >= srelen) {
+ printf(", badoff/len=%u/%u", sreoff, srelen);
+ return;
+ }
+
+ for (;;) {
+ if (len < 4 || srelen == 0)
+ return;
+
+ memcpy(&a, bp, sizeof(a));
+ printf(" %s%s",
+ ((bp - up) == sreoff) ? "*" : "",
+ inet_ntoa(a));
+
+ bp += 4;
+ len -= 4;
+ srelen -= 4;
+ }
+}
+
+void
+gre_sre_asn_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
+{
+ const u_char *up = bp;
+
+ if (sreoff & 1) {
+ printf(", badoffset=%u", sreoff);
+ return;
+ }
+ if (srelen & 1) {
+ printf(", badlength=%u", srelen);
+ return;
+ }
+ if (sreoff >= srelen) {
+ printf(", badoff/len=%u/%u", sreoff, srelen);
+ return;
+ }
+
+ for (;;) {
+ if (len < 2 || srelen == 0)
+ return;
+
+ printf(" %s%x",
+ ((bp - up) == sreoff) ? "*" : "",
+ EXTRACT_16BITS(bp));
+
+ bp += 2;
+ len -= 2;
+ srelen -= 2;
+ }