+/*
+ * PPP I/F printer to use if we know that RFC 1662-style PPP in HDLC-like
+ * framing, or Cisco PPP with HDLC framing as per section 4.3.1 of RFC 1547,
+ * is being used (i.e., we don't check for PPP_ADDRESS and PPP_CONTROL,
+ * discard them *if* those are the first two octets, and parse the remaining
+ * packet as a PPP packet, as "ppp_print()" does).
+ *
+ * This handles, for example, DLT_PPP_SERIAL in NetBSD.
+ */
+void
+ppp_hdlc_if_print(u_char *user, const struct pcap_pkthdr *h,
+ register const u_char *p)
+{
+ register u_int length = h->len;
+ register u_int caplen = h->caplen;
+ u_int proto;
+
+ if (caplen < 2) {
+ printf("[|ppp]");
+ goto out;
+ }
+
+ /*
+ * Some printers want to get back at the link level addresses,
+ * and/or check that they're not walking off the end of the packet.
+ * Rather than pass them all the way down, we set these globals.
+ */
+ packetp = p;
+ snapend = p + caplen;
+
+ switch (p[0]) {
+
+ case PPP_ADDRESS:
+ if (caplen < 4) {
+ printf("[|ppp]");
+ goto out;
+ }
+
+ ts_print(&h->ts);
+ if (eflag)
+ printf("%02x %02x %d ", p[0], p[1], length);
+ p += 2;
+ length -= 2;
+
+ proto = EXTRACT_16BITS(p);
+ p += 2;
+ length -= 2;
+ printf("%s: ", ppp_protoname(proto));
+
+ handle_ppp(proto, p, length);
+ break;
+
+ case CHDLC_UNICAST:
+ case CHDLC_BCAST:
+ /*
+ * Have the Cisco HDLC print routine do all the work.
+ */
+ chdlc_if_print(user, h, p);
+ return;
+
+ default:
+ ts_print(&h->ts);
+ if (eflag)
+ printf("%02x %02x %d ", p[0], p[1], length);
+ p += 2;
+ length -= 2;
+
+ /*
+ * XXX - NetBSD's "ppp_netbsd_serial_if_print()" treats
+ * the next two octets as an Ethernet type; does that
+ * ever happen?
+ */
+ printf("unknown addr %02x; ctrl %02x", p[0], p[1]);
+ break;
+ }
+
+ if (xflag)
+ default_print(p, caplen);
+out:
+ putchar('\n');
+}
+
projects / tcpdump / blobdiff