diff options
Diffstat (limited to '')
| -rw-r--r-- | print-llc.c | 610 |
1 files changed, 610 insertions, 0 deletions
diff --git a/print-llc.c b/print-llc.c new file mode 100644 index 0000000..ae3ae4c --- /dev/null +++ b/print-llc.c @@ -0,0 +1,610 @@ +/* + * 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); +} |