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+/*
+ * Copyright (c) 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.
+ *
+ * Code by Matt Thomas, Digital Equipment Corporation
+ * with an awful lot of hacking by Jeffrey Mogul, DECWRL
+ */
+
+/* \summary: IEEE 802.2 LLC printer */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "netdissect-stdinc.h"
+
+#include "netdissect.h"
+#include "addrtoname.h"
+#include "extract.h"
+
+#include "llc.h"
+#include "ethertype.h"
+#include "oui.h"
+
+static const struct tok llc_values[] = {
+ { LLCSAP_NULL, "Null" },
+ { LLCSAP_GLOBAL, "Global" },
+ { LLCSAP_8021B_I, "802.1B I" },
+ { LLCSAP_8021B_G, "802.1B G" },
+ { LLCSAP_IP, "IP" },
+ { LLCSAP_SNA, "SNA" },
+ { LLCSAP_PROWAYNM, "ProWay NM" },
+ { LLCSAP_8021D, "STP" },
+ { LLCSAP_RS511, "RS511" },
+ { LLCSAP_ISO8208, "ISO8208" },
+ { LLCSAP_PROWAY, "ProWay" },
+ { LLCSAP_SNAP, "SNAP" },
+ { LLCSAP_IPX, "IPX" },
+ { LLCSAP_NETBEUI, "NetBeui" },
+ { LLCSAP_ISONS, "OSI" },
+ { 0, NULL },
+};
+
+static const struct tok llc_cmd_values[] = {
+ { LLC_UI, "ui" },
+ { LLC_TEST, "test" },
+ { LLC_XID, "xid" },
+ { LLC_UA, "ua" },
+ { LLC_DISC, "disc" },
+ { LLC_DM, "dm" },
+ { LLC_SABME, "sabme" },
+ { LLC_FRMR, "frmr" },
+ { 0, NULL }
+};
+
+static const struct tok llc_flag_values[] = {
+ { 0, "Command" },
+ { LLC_GSAP, "Response" },
+ { LLC_U_POLL, "Poll" },
+ { LLC_GSAP|LLC_U_POLL, "Final" },
+ { LLC_IS_POLL, "Poll" },
+ { LLC_GSAP|LLC_IS_POLL, "Final" },
+ { 0, NULL }
+};
+
+
+static const struct tok llc_ig_flag_values[] = {
+ { 0, "Individual" },
+ { LLC_IG, "Group" },
+ { 0, NULL }
+};
+
+
+static const struct tok llc_supervisory_values[] = {
+ { 0, "Receiver Ready" },
+ { 1, "Receiver not Ready" },
+ { 2, "Reject" },
+ { 0, NULL }
+};
+
+
+static const struct tok cisco_values[] = {
+ { PID_CISCO_CDP, "CDP" },
+ { PID_CISCO_VTP, "VTP" },
+ { PID_CISCO_DTP, "DTP" },
+ { PID_CISCO_UDLD, "UDLD" },
+ { PID_CISCO_PVST, "PVST" },
+ { PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
+ { 0, NULL }
+};
+
+static const struct tok bridged_values[] = {
+ { PID_RFC2684_ETH_FCS, "Ethernet + FCS" },
+ { PID_RFC2684_ETH_NOFCS, "Ethernet w/o FCS" },
+ { PID_RFC2684_802_4_FCS, "802.4 + FCS" },
+ { PID_RFC2684_802_4_NOFCS, "802.4 w/o FCS" },
+ { PID_RFC2684_802_5_FCS, "Token Ring + FCS" },
+ { PID_RFC2684_802_5_NOFCS, "Token Ring w/o FCS" },
+ { PID_RFC2684_FDDI_FCS, "FDDI + FCS" },
+ { PID_RFC2684_FDDI_NOFCS, "FDDI w/o FCS" },
+ { PID_RFC2684_802_6_FCS, "802.6 + FCS" },
+ { PID_RFC2684_802_6_NOFCS, "802.6 w/o FCS" },
+ { PID_RFC2684_BPDU, "BPDU" },
+ { 0, NULL },
+};
+
+static const struct tok null_values[] = {
+ { 0, NULL }
+};
+
+struct oui_tok {
+ uint32_t oui;
+ const struct tok *tok;
+};
+
+static const struct oui_tok oui_to_tok[] = {
+ { OUI_ENCAP_ETHER, ethertype_values },
+ { OUI_CISCO_90, ethertype_values }, /* uses some Ethertype values */
+ { OUI_APPLETALK, ethertype_values }, /* uses some Ethertype values */
+ { OUI_CISCO, cisco_values },
+ { OUI_RFC2684, bridged_values }, /* bridged, RFC 2427 FR or RFC 2864 ATM */
+ { 0, NULL }
+};
+
+/*
+ * If we printed information about the payload, returns the length of the LLC
+ * header, plus the length of any SNAP header following it.
+ *
+ * Otherwise (for example, if the packet has unknown SAPs or has a SNAP
+ * header with an unknown OUI/PID combination), returns the *negative*
+ * of that value.
+ */
+int
+llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
+ const struct lladdr_info *src, const struct lladdr_info *dst)
+{
+ uint8_t dsap_field, dsap, ssap_field, ssap;
+ uint16_t control;
+ int hdrlen;
+ int is_u;
+
+ ndo->ndo_protocol = "llc";
+ if (caplen < 3) {
+ nd_print_trunc(ndo);
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ return (caplen);
+ }
+ if (length < 3) {
+ nd_print_trunc(ndo);
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ return (length);
+ }
+
+ dsap_field = GET_U_1(p);
+ ssap_field = GET_U_1(p + 1);
+
+ /*
+ * OK, what type of LLC frame is this? The length
+ * of the control field depends on that - I frames
+ * have a two-byte control field, and U frames have
+ * a one-byte control field.
+ */
+ control = GET_U_1(p + 2);
+ if ((control & LLC_U_FMT) == LLC_U_FMT) {
+ /*
+ * U frame.
+ */
+ is_u = 1;
+ hdrlen = 3; /* DSAP, SSAP, 1-byte control field */
+ } else {
+ /*
+ * The control field in I and S frames is
+ * 2 bytes...
+ */
+ if (caplen < 4) {
+ nd_print_trunc(ndo);
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ return (caplen);
+ }
+ if (length < 4) {
+ nd_print_trunc(ndo);
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ return (length);
+ }
+
+ /*
+ * ...and is little-endian.
+ */
+ control = GET_LE_U_2(p + 2);
+ is_u = 0;
+ hdrlen = 4; /* DSAP, SSAP, 2-byte control field */
+ }
+
+ if (ssap_field == LLCSAP_GLOBAL && dsap_field == LLCSAP_GLOBAL) {
+ /*
+ * This is an Ethernet_802.3 IPX frame; it has an
+ * 802.3 header (i.e., an Ethernet header where the
+ * type/length field is <= MAX_ETHERNET_LENGTH_VAL,
+ * i.e. it's a length field, not a type field), but
+ * has no 802.2 header - the IPX packet starts right
+ * after the Ethernet header, with a signature of two
+ * bytes of 0xFF (which is LLCSAP_GLOBAL).
+ *
+ * (It might also have been an Ethernet_802.3 IPX at
+ * one time, but got bridged onto another network,
+ * such as an 802.11 network; this has appeared in at
+ * least one capture file.)
+ */
+
+ if (ndo->ndo_eflag)
+ ND_PRINT("IPX 802.3: ");
+
+ ipx_print(ndo, p, length);
+ return (0); /* no LLC header */
+ }
+
+ dsap = dsap_field & ~LLC_IG;
+ ssap = ssap_field & ~LLC_GSAP;
+
+ if (ndo->ndo_eflag) {
+ ND_PRINT("LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
+ tok2str(llc_values, "Unknown", dsap),
+ dsap,
+ tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
+ tok2str(llc_values, "Unknown", ssap),
+ ssap,
+ tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP));
+
+ if (is_u) {
+ ND_PRINT(", ctrl 0x%02x: ", control);
+ } else {
+ ND_PRINT(", ctrl 0x%04x: ", control);
+ }
+ }
+
+ /*
+ * Skip LLC header.
+ */
+ p += hdrlen;
+ length -= hdrlen;
+ caplen -= hdrlen;
+
+ if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
+ && control == LLC_UI) {
+ /*
+ * XXX - what *is* the right bridge pad value here?
+ * Does anybody ever bridge one form of LAN traffic
+ * over a networking type that uses 802.2 LLC?
+ */
+ if (!snap_print(ndo, p, length, caplen, src, dst, 2)) {
+ /*
+ * Unknown packet type; tell our caller, by
+ * returning a negative value, so they
+ * can print the raw packet.
+ */
+ return (-(hdrlen + 5)); /* include LLC and SNAP header */
+ } else
+ return (hdrlen + 5); /* include LLC and SNAP header */
+ }
+
+ if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
+ control == LLC_UI) {
+ stp_print(ndo, p, length);
+ return (hdrlen);
+ }
+
+ if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
+ control == LLC_UI) {
+ /*
+ * This is an RFC 948-style IP packet, with
+ * an 802.3 header and an 802.2 LLC header
+ * with the source and destination SAPs being
+ * the IP SAP.
+ */
+ ip_print(ndo, p, length);
+ return (hdrlen);
+ }
+
+ if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
+ control == LLC_UI) {
+ /*
+ * This is an Ethernet_802.2 IPX frame, with an 802.3
+ * header and an 802.2 LLC header with the source and
+ * destination SAPs being the IPX SAP.
+ */
+ if (ndo->ndo_eflag)
+ ND_PRINT("IPX 802.2: ");
+
+ ipx_print(ndo, p, length);
+ return (hdrlen);
+ }
+
+#ifdef ENABLE_SMB
+ if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
+ && (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
+ /*
+ * we don't actually have a full netbeui parser yet, but the
+ * smb parser can handle many smb-in-netbeui packets, which
+ * is very useful, so we call that
+ *
+ * We don't call it for S frames, however, just I frames
+ * (which are frames that don't have the low-order bit,
+ * LLC_S_FMT, set in the first byte of the control field)
+ * and UI frames (whose control field is just 3, LLC_U_FMT).
+ */
+ netbeui_print(ndo, control, p, length);
+ return (hdrlen);
+ }
+#endif
+ if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
+ && control == LLC_UI) {
+ isoclns_print(ndo, p, length);
+ return (hdrlen);
+ }
+
+ if (!ndo->ndo_eflag) {
+ if (ssap == dsap) {
+ if (src == NULL || dst == NULL)
+ ND_PRINT("%s ", tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
+ else
+ ND_PRINT("%s > %s %s ",
+ (src->addr_string)(ndo, src->addr),
+ (dst->addr_string)(ndo, dst->addr),
+ tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
+ } else {
+ if (src == NULL || dst == NULL)
+ ND_PRINT("%s > %s ",
+ tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
+ tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
+ else
+ ND_PRINT("%s %s > %s %s ",
+ (src->addr_string)(ndo, src->addr),
+ tok2str(llc_values, "Unknown SSAP 0x%02x", ssap),
+ (dst->addr_string)(ndo, dst->addr),
+ tok2str(llc_values, "Unknown DSAP 0x%02x", dsap));
+ }
+ }
+
+ if (is_u) {
+ ND_PRINT("Unnumbered, %s, Flags [%s], length %u",
+ tok2str(llc_cmd_values, "%02x", LLC_U_CMD(control)),
+ tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_U_POLL)),
+ length + hdrlen);
+
+ if ((control & ~LLC_U_POLL) == LLC_XID) {
+ if (length == 0) {
+ /*
+ * XID with no payload.
+ * This could, for example, be an SNA
+ * "short form" XID.
+ */
+ return (hdrlen);
+ }
+ if (caplen < 1) {
+ nd_print_trunc(ndo);
+ if (caplen > 0)
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ return (hdrlen);
+ }
+ if (GET_U_1(p) == LLC_XID_FI) {
+ if (caplen < 3 || length < 3) {
+ nd_print_trunc(ndo);
+ if (caplen > 0)
+ ND_DEFAULTPRINT((const u_char *)p, caplen);
+ } else
+ ND_PRINT(": %02x %02x",
+ GET_U_1(p + 1),
+ GET_U_1(p + 2));
+ return (hdrlen);
+ }
+ }
+ } else {
+ if ((control & LLC_S_FMT) == LLC_S_FMT) {
+ ND_PRINT("Supervisory, %s, rcv seq %u, Flags [%s], length %u",
+ tok2str(llc_supervisory_values,"?",LLC_S_CMD(control)),
+ LLC_IS_NR(control),
+ tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
+ length + hdrlen);
+ return (hdrlen); /* no payload to print */
+ } else {
+ ND_PRINT("Information, send seq %u, rcv seq %u, Flags [%s], length %u",
+ LLC_I_NS(control),
+ LLC_IS_NR(control),
+ tok2str(llc_flag_values,"?",(ssap_field & LLC_GSAP) | (control & LLC_IS_POLL)),
+ length + hdrlen);
+ }
+ }
+ return (-hdrlen);
+}
+
+static const struct tok *
+oui_to_struct_tok(uint32_t orgcode)
+{
+ const struct tok *tok = null_values;
+ const struct oui_tok *otp;
+
+ for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
+ if (otp->oui == orgcode) {
+ tok = otp->tok;
+ break;
+ }
+ }
+ return (tok);
+}
+
+int
+snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
+ const struct lladdr_info *src, const struct lladdr_info *dst,
+ u_int bridge_pad)
+{
+ uint32_t orgcode;
+ u_short et;
+ int ret;
+
+ ndo->ndo_protocol = "snap";
+ ND_TCHECK_5(p);
+ if (caplen < 5 || length < 5)
+ goto trunc;
+ orgcode = GET_BE_U_3(p);
+ et = GET_BE_U_2(p + 3);
+
+ if (ndo->ndo_eflag) {
+ /*
+ * Somebody's already printed the MAC addresses, if there
+ * are any, so just print the SNAP header, not the MAC
+ * addresses.
+ */
+ ND_PRINT("oui %s (0x%06x), %s %s (0x%04x), length %u: ",
+ tok2str(oui_values, "Unknown", orgcode),
+ orgcode,
+ (orgcode == 0x000000 ? "ethertype" : "pid"),
+ tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
+ et, length - 5);
+ }
+ p += 5;
+ length -= 5;
+ caplen -= 5;
+
+ switch (orgcode) {
+ case OUI_ENCAP_ETHER:
+ case OUI_CISCO_90:
+ /*
+ * This is an encapsulated Ethernet packet,
+ * or a packet bridged by some piece of
+ * Cisco hardware; the protocol ID is
+ * an Ethernet protocol type.
+ */
+ ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
+ if (ret)
+ return (ret);
+ break;
+
+ case OUI_APPLETALK:
+ if (et == ETHERTYPE_ATALK) {
+ /*
+ * No, I have no idea why Apple used one
+ * of their own OUIs, rather than
+ * 0x000000, and an Ethernet packet
+ * type, for Appletalk data packets,
+ * but used 0x000000 and an Ethernet
+ * packet type for AARP packets.
+ */
+ ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
+ if (ret)
+ return (ret);
+ }
+ break;
+
+ case OUI_CISCO:
+ switch (et) {
+ case PID_CISCO_CDP:
+ cdp_print(ndo, p, length);
+ return (1);
+ case PID_CISCO_DTP:
+ dtp_print(ndo, p, length);
+ return (1);
+ case PID_CISCO_UDLD:
+ udld_print(ndo, p, length);
+ return (1);
+ case PID_CISCO_VTP:
+ vtp_print(ndo, p, length);
+ return (1);
+ case PID_CISCO_PVST:
+ case PID_CISCO_VLANBRIDGE:
+ stp_print(ndo, p, length);
+ return (1);
+ default:
+ break;
+ }
+ break;
+
+ case OUI_RFC2684:
+ switch (et) {
+
+ case PID_RFC2684_ETH_FCS:
+ case PID_RFC2684_ETH_NOFCS:
+ /*
+ * XXX - remove the last two bytes for
+ * PID_RFC2684_ETH_FCS?
+ */
+ /*
+ * Skip the padding.
+ */
+ ND_TCHECK_LEN(p, bridge_pad);
+ caplen -= bridge_pad;
+ length -= bridge_pad;
+ p += bridge_pad;
+
+ /*
+ * What remains is an Ethernet packet.
+ */
+ ether_print(ndo, p, length, caplen, NULL, NULL);
+ return (1);
+
+ case PID_RFC2684_802_5_FCS:
+ case PID_RFC2684_802_5_NOFCS:
+ /*
+ * XXX - remove the last two bytes for
+ * PID_RFC2684_ETH_FCS?
+ */
+ /*
+ * Skip the padding, but not the Access
+ * Control field.
+ */
+ ND_TCHECK_LEN(p, bridge_pad);
+ caplen -= bridge_pad;
+ length -= bridge_pad;
+ p += bridge_pad;
+
+ /*
+ * What remains is an 802.5 Token Ring
+ * packet.
+ */
+ token_print(ndo, p, length, caplen);
+ return (1);
+
+ case PID_RFC2684_FDDI_FCS:
+ case PID_RFC2684_FDDI_NOFCS:
+ /*
+ * XXX - remove the last two bytes for
+ * PID_RFC2684_ETH_FCS?
+ */
+ /*
+ * Skip the padding.
+ */
+ ND_TCHECK_LEN(p, bridge_pad + 1);
+ caplen -= bridge_pad + 1;
+ length -= bridge_pad + 1;
+ p += bridge_pad + 1;
+
+ /*
+ * What remains is an FDDI packet.
+ */
+ fddi_print(ndo, p, length, caplen);
+ return (1);
+
+ case PID_RFC2684_BPDU:
+ stp_print(ndo, p, length);
+ return (1);
+ }
+ }
+ if (!ndo->ndo_eflag) {
+ /*
+ * Nobody printed the link-layer addresses, so print them, if
+ * we have any.
+ */
+ if (src != NULL && dst != NULL) {
+ ND_PRINT("%s > %s ",
+ (src->addr_string)(ndo, src->addr),
+ (dst->addr_string)(ndo, dst->addr));
+ }
+ /*
+ * Print the SNAP header, but if the OUI is 000000, don't
+ * bother printing it, and report the PID as being an
+ * ethertype.
+ */
+ if (orgcode == 0x000000) {
+ ND_PRINT("SNAP, ethertype %s (0x%04x), length %u: ",
+ tok2str(ethertype_values, "Unknown", et),
+ et, length);
+ } else {
+ ND_PRINT("SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ",
+ tok2str(oui_values, "Unknown", orgcode),
+ orgcode,
+ tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
+ et, length);
+ }
+ }
+ return (0);
+
+trunc:
+ nd_print_trunc(ndo);
+ return (1);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 01:02:52 +0000