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-rw-r--r--print-chdlc.c198
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diff --git a/print-chdlc.c b/print-chdlc.c
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+/*
+ * Copyright (c) 1990, 1991, 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.
+ */
+
+/* \summary: Cisco HDLC printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "ethertype.h"
+#include "extract.h"
+#include "chdlc.h"
+#include "nlpid.h"
+
+static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
+
+static const struct tok chdlc_cast_values[] = {
+ { CHDLC_UNICAST, "unicast" },
+ { CHDLC_BCAST, "bcast" },
+ { 0, NULL}
+};
+
+
+/* Standard CHDLC printer */
+void
+chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
+{
+ ndo->ndo_protocol = "chdlc";
+ ndo->ndo_ll_hdr_len += chdlc_print(ndo, p, h->len);
+}
+
+u_int
+chdlc_print(netdissect_options *ndo, const u_char *p, u_int length)
+{
+ u_int proto;
+ const u_char *bp = p;
+
+ ndo->ndo_protocol = "chdlc";
+ if (length < CHDLC_HDRLEN)
+ goto trunc;
+ proto = GET_BE_U_2(p + 2);
+ if (ndo->ndo_eflag) {
+ ND_PRINT("%s, ethertype %s (0x%04x), length %u: ",
+ tok2str(chdlc_cast_values, "0x%02x", GET_U_1(p)),
+ tok2str(ethertype_values, "Unknown", proto),
+ proto,
+ length);
+ }
+
+ length -= CHDLC_HDRLEN;
+ p += CHDLC_HDRLEN;
+
+ switch (proto) {
+ case ETHERTYPE_IP:
+ ip_print(ndo, p, length);
+ break;
+ case ETHERTYPE_IPV6:
+ ip6_print(ndo, p, length);
+ break;
+ case CHDLC_TYPE_SLARP:
+ chdlc_slarp_print(ndo, p, length);
+ break;
+ case ETHERTYPE_MPLS:
+ case ETHERTYPE_MPLS_MULTI:
+ mpls_print(ndo, p, length);
+ break;
+ case ETHERTYPE_ISO:
+ /* is the fudge byte set ? lets verify by spotting ISO headers */
+ if (length < 2)
+ goto trunc;
+ if (GET_U_1(p + 1) == NLPID_CLNP ||
+ GET_U_1(p + 1) == NLPID_ESIS ||
+ GET_U_1(p + 1) == NLPID_ISIS)
+ isoclns_print(ndo, p + 1, length - 1);
+ else
+ isoclns_print(ndo, p, length);
+ break;
+ default:
+ if (!ndo->ndo_eflag)
+ ND_PRINT("unknown CHDLC protocol (0x%04x)", proto);
+ break;
+ }
+
+ return (CHDLC_HDRLEN);
+
+trunc:
+ nd_print_trunc(ndo);
+ return (ND_BYTES_AVAILABLE_AFTER(bp));
+}
+
+/*
+ * The fixed-length portion of a SLARP packet.
+ */
+struct cisco_slarp {
+ nd_uint32_t code;
+#define SLARP_REQUEST 0
+#define SLARP_REPLY 1
+#define SLARP_KEEPALIVE 2
+ union {
+ struct {
+ uint8_t addr[4];
+ uint8_t mask[4];
+ } addr;
+ struct {
+ nd_uint32_t myseq;
+ nd_uint32_t yourseq;
+ nd_uint16_t rel;
+ } keep;
+ } un;
+};
+
+#define SLARP_MIN_LEN 14
+#define SLARP_MAX_LEN 18
+
+static void
+chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length)
+{
+ const struct cisco_slarp *slarp;
+ u_int sec,min,hrs,days;
+
+ ndo->ndo_protocol = "chdlc_slarp";
+ ND_PRINT("SLARP (length: %u), ",length);
+ if (length < SLARP_MIN_LEN)
+ goto trunc;
+
+ slarp = (const struct cisco_slarp *)cp;
+ ND_TCHECK_LEN(slarp, SLARP_MIN_LEN);
+ switch (GET_BE_U_4(slarp->code)) {
+ case SLARP_REQUEST:
+ ND_PRINT("request");
+ /*
+ * At least according to William "Chops" Westfield's
+ * message in
+ *
+ * https://web.archive.org/web/20190725151313/www.nethelp.no/net/cisco-hdlc.txt
+ *
+ * the address and mask aren't used in requests -
+ * they're just zero.
+ */
+ break;
+ case SLARP_REPLY:
+ ND_PRINT("reply %s/%s",
+ GET_IPADDR_STRING(slarp->un.addr.addr),
+ GET_IPADDR_STRING(slarp->un.addr.mask));
+ break;
+ case SLARP_KEEPALIVE:
+ ND_PRINT("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
+ GET_BE_U_4(slarp->un.keep.myseq),
+ GET_BE_U_4(slarp->un.keep.yourseq),
+ GET_BE_U_2(slarp->un.keep.rel));
+
+ if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
+ cp += SLARP_MIN_LEN;
+ sec = GET_BE_U_4(cp) / 1000;
+ min = sec / 60; sec -= min * 60;
+ hrs = min / 60; min -= hrs * 60;
+ days = hrs / 24; hrs -= days * 24;
+ ND_PRINT(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
+ }
+ break;
+ default:
+ ND_PRINT("0x%02x unknown", GET_BE_U_4(slarp->code));
+ if (ndo->ndo_vflag <= 1)
+ print_unknown_data(ndo,cp+4,"\n\t",length-4);
+ break;
+ }
+
+ if (SLARP_MAX_LEN < length && ndo->ndo_vflag)
+ ND_PRINT(", (trailing junk: %u bytes)", length - SLARP_MAX_LEN);
+ if (ndo->ndo_vflag > 1)
+ print_unknown_data(ndo,cp+4,"\n\t",length-4);
+ return;
+
+trunc:
+ nd_print_trunc(ndo);
+}