X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/eba1a415343eef5b411c8b20fdf43fe034fe153c..47fc89d711eec0a073d9b3b293a1af901b5bd791:/print-l2tp.c diff --git a/print-l2tp.c b/print-l2tp.c index 67a3059a..ca98e9a9 100644 --- a/print-l2tp.c +++ b/print-l2tp.c @@ -21,34 +21,54 @@ * L2TP support contributed by Motonori Shindo (mshindo@mshindo.net) */ -#ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-l2tp.c,v 1.11 2002-05-25 09:41:07 guy Exp $"; -#endif - #ifdef HAVE_CONFIG_H #include "config.h" #endif +#include + #include -#include -#include -#include -#include -#include "l2tp.h" #include "interface.h" #include "extract.h" -static char tstr[] = " [|l2tp]"; +#define L2TP_FLAG_TYPE 0x8000 /* Type (0=Data, 1=Control) */ +#define L2TP_FLAG_LENGTH 0x4000 /* Length */ +#define L2TP_FLAG_SEQUENCE 0x0800 /* Sequence */ +#define L2TP_FLAG_OFFSET 0x0200 /* Offset */ +#define L2TP_FLAG_PRIORITY 0x0100 /* Priority */ -#ifndef TRUE -#define TRUE 1 -#endif +#define L2TP_VERSION_MASK 0x000f /* Version Mask */ +#define L2TP_VERSION_L2F 0x0001 /* L2F */ +#define L2TP_VERSION_L2TP 0x0002 /* L2TP */ -#ifndef FALSE -#define FALSE 0 -#endif +#define L2TP_AVP_HDR_FLAG_MANDATORY 0x8000 /* Mandatory Flag */ +#define L2TP_AVP_HDR_FLAG_HIDDEN 0x4000 /* Hidden Flag */ +#define L2TP_AVP_HDR_LEN_MASK 0x03ff /* Length Mask */ + +#define L2TP_FRAMING_CAP_SYNC_MASK 0x00000001 /* Synchronous */ +#define L2TP_FRAMING_CAP_ASYNC_MASK 0x00000002 /* Asynchronous */ + +#define L2TP_FRAMING_TYPE_SYNC_MASK 0x00000001 /* Synchronous */ +#define L2TP_FRAMING_TYPE_ASYNC_MASK 0x00000002 /* Asynchronous */ + +#define L2TP_BEARER_CAP_DIGITAL_MASK 0x00000001 /* Digital */ +#define L2TP_BEARER_CAP_ANALOG_MASK 0x00000002 /* Analog */ + +#define L2TP_BEARER_TYPE_DIGITAL_MASK 0x00000001 /* Digital */ +#define L2TP_BEARER_TYPE_ANALOG_MASK 0x00000002 /* Analog */ + +/* Authen Type */ +#define L2TP_AUTHEN_TYPE_RESERVED 0x0000 /* Reserved */ +#define L2TP_AUTHEN_TYPE_TEXTUAL 0x0001 /* Textual username/password exchange */ +#define L2TP_AUTHEN_TYPE_CHAP 0x0002 /* PPP CHAP */ +#define L2TP_AUTHEN_TYPE_PAP 0x0003 /* PPP PAP */ +#define L2TP_AUTHEN_TYPE_NO_AUTH 0x0004 /* No Authentication */ +#define L2TP_AUTHEN_TYPE_MSCHAPv1 0x0005 /* MSCHAPv1 */ + +#define L2TP_PROXY_AUTH_ID_MASK 0x00ff + +static const char tstr[] = " [|l2tp]"; #define L2TP_MSGTYPE_SCCRQ 1 /* Start-Control-Connection-Request */ #define L2TP_MSGTYPE_SCCRP 2 /* Start-Control-Connection-Reply */ @@ -65,7 +85,7 @@ static char tstr[] = " [|l2tp]"; #define L2TP_MSGTYPE_WEN 15 /* WAN-Error-Notify */ #define L2TP_MSGTYPE_SLI 16 /* Set-Link-Info */ -static struct tok l2tp_msgtype2str[] = { +static const struct tok l2tp_msgtype2str[] = { { L2TP_MSGTYPE_SCCRQ, "SCCRQ" }, { L2TP_MSGTYPE_SCCRP, "SCCRP" }, { L2TP_MSGTYPE_SCCCN, "SCCCN" }, @@ -125,7 +145,7 @@ static struct tok l2tp_msgtype2str[] = { #define L2TP_AVP_SEQ_REQUIRED 39 /* Sequencing Required */ #define L2TP_AVP_PPP_DISCON_CC 46 /* PPP Disconnect Cause Code */ -static struct tok l2tp_avp2str[] = { +static const struct tok l2tp_avp2str[] = { { L2TP_AVP_MSGTYPE, "MSGTYPE" }, { L2TP_AVP_RESULT_CODE, "RESULT_CODE" }, { L2TP_AVP_PROTO_VER, "PROTO_VER" }, @@ -146,31 +166,31 @@ static struct tok l2tp_avp2str[] = { { L2TP_AVP_MAXIMUM_BPS, "MAXIMUM_BPS" }, { L2TP_AVP_BEARER_TYPE, "BEARER_TYPE" }, { L2TP_AVP_FRAMING_TYPE, "FRAMING_TYPE" }, - { L2TP_AVP_PACKET_PROC_DELAY, "PACKET_PROC_DELAY" }, + { L2TP_AVP_PACKET_PROC_DELAY, "PACKET_PROC_DELAY" }, { L2TP_AVP_CALLED_NUMBER, "CALLED_NUMBER" }, { L2TP_AVP_CALLING_NUMBER, "CALLING_NUMBER" }, { L2TP_AVP_SUB_ADDRESS, "SUB_ADDRESS" }, { L2TP_AVP_TX_CONN_SPEED, "TX_CONN_SPEED" }, { L2TP_AVP_PHY_CHANNEL_ID, "PHY_CHANNEL_ID" }, { L2TP_AVP_INI_RECV_LCP, "INI_RECV_LCP" }, - { L2TP_AVP_LAST_SENT_LCP, "LAST_SENT_LCP" }, - { L2TP_AVP_LAST_RECV_LCP, "LAST_RECV_LCP" }, - { L2TP_AVP_PROXY_AUTH_TYPE, "PROXY_AUTH_TYPE" }, + { L2TP_AVP_LAST_SENT_LCP, "LAST_SENT_LCP" }, + { L2TP_AVP_LAST_RECV_LCP, "LAST_RECV_LCP" }, + { L2TP_AVP_PROXY_AUTH_TYPE, "PROXY_AUTH_TYPE" }, { L2TP_AVP_PROXY_AUTH_NAME, "PROXY_AUTH_NAME" }, - { L2TP_AVP_PROXY_AUTH_CHAL, "PROXY_AUTH_CHAL" }, + { L2TP_AVP_PROXY_AUTH_CHAL, "PROXY_AUTH_CHAL" }, { L2TP_AVP_PROXY_AUTH_ID, "PROXY_AUTH_ID" }, { L2TP_AVP_PROXY_AUTH_RESP, "PROXY_AUTH_RESP" }, { L2TP_AVP_CALL_ERRORS, "CALL_ERRORS" }, - { L2TP_AVP_ACCM, "ACCM" }, - { L2TP_AVP_RANDOM_VECTOR, "RANDOM_VECTOR" }, + { L2TP_AVP_ACCM, "ACCM" }, + { L2TP_AVP_RANDOM_VECTOR, "RANDOM_VECTOR" }, { L2TP_AVP_PRIVATE_GRP_ID, "PRIVATE_GRP_ID" }, - { L2TP_AVP_RX_CONN_SPEED, "RX_CONN_SPEED" }, - { L2TP_AVP_SEQ_REQUIRED, "SEQ_REQUIRED" }, - { L2TP_AVP_PPP_DISCON_CC, "PPP_DISCON_CC" }, + { L2TP_AVP_RX_CONN_SPEED, "RX_CONN_SPEED" }, + { L2TP_AVP_SEQ_REQUIRED, "SEQ_REQUIRED" }, + { L2TP_AVP_PPP_DISCON_CC, "PPP_DISCON_CC" }, { 0, NULL } }; -static struct tok l2tp_authentype2str[] = { +static const struct tok l2tp_authentype2str[] = { { L2TP_AUTHEN_TYPE_RESERVED, "Reserved" }, { L2TP_AUTHEN_TYPE_TEXTUAL, "Textual" }, { L2TP_AUTHEN_TYPE_CHAP, "CHAP" }, @@ -184,7 +204,7 @@ static struct tok l2tp_authentype2str[] = { #define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER 1 #define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL 2 -static struct tok l2tp_cc_direction2str[] = { +static const struct tok l2tp_cc_direction2str[] = { { L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL, "global error" }, { L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER, "at peer" }, { L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" }, @@ -243,19 +263,19 @@ static char *l2tp_error_code_general[] = { /******************************/ /* generic print out routines */ /******************************/ -static void +static void print_string(const u_char *dat, u_int length) { - int i; + u_int i; for (i=0; i 2) { /* Error Code (opt) */ printf("/%u", EXTRACT_16BITS(ptr)); ptr++; @@ -341,7 +361,7 @@ l2tp_q931_cc_print(const u_char *dat, u_int length) if (length > 3) { printf(" "); print_string(dat+3, length-3); - } + } } static void @@ -381,7 +401,7 @@ l2tp_proxy_auth_type_print(const u_char *dat) { u_int16_t *ptr = (u_int16_t *)dat; - printf("%s", tok2str(l2tp_authentype2str, + printf("%s", tok2str(l2tp_authentype2str, "AuthType-#%u", EXTRACT_16BITS(ptr))); } @@ -398,7 +418,7 @@ l2tp_call_errors_print(const u_char *dat) { u_int16_t *ptr = (u_int16_t *)dat; u_int16_t val_h, val_l; - + ptr++; /* skip "Reserved" */ val_h = EXTRACT_16BITS(ptr); ptr++; @@ -437,7 +457,7 @@ l2tp_accm_print(const u_char *dat) val_h = EXTRACT_16BITS(ptr); ptr++; val_l = EXTRACT_16BITS(ptr); ptr++; printf("send=%08x ", (val_h<<16) + val_l); - + val_h = EXTRACT_16BITS(ptr); ptr++; val_l = EXTRACT_16BITS(ptr); ptr++; printf("recv=%08x ", (val_h<<16) + val_l); @@ -447,10 +467,10 @@ static void l2tp_ppp_discon_cc_print(const u_char *dat, u_int length) { u_int16_t *ptr = (u_int16_t *)dat; - + printf("%04x, ", EXTRACT_16BITS(ptr)); ptr++; /* Disconnect Code */ printf("%04x ", EXTRACT_16BITS(ptr)); ptr++; /* Control Protocol Number */ - printf("%s", tok2str(l2tp_cc_direction2str, + printf("%s", tok2str(l2tp_cc_direction2str, "Direction-#%u", *((u_char *)ptr++))); if (length > 5) { @@ -476,8 +496,17 @@ l2tp_avp_print(const u_char *dat, int length) TCHECK(*ptr); /* Flags & Length */ len = EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_LEN_MASK; - /* If it is not long enough to decode the entire AVP, we'll - abandon. */ + /* If it is not long enough to contain the header, we'll give up. */ + if (len < 6) + goto trunc; + + /* If it goes past the end of the remaining length of the packet, + we'll give up. */ + if (len > (u_int)length) + goto trunc; + + /* If it goes past the end of the remaining length of the captured + data, we'll give up. */ TCHECK2(*ptr, len); /* After this point, no need to worry about truncation */ @@ -498,7 +527,7 @@ l2tp_avp_print(const u_char *dat, int length) print_octets((u_char *)ptr, len-6); printf(")"); } else { - /* IETF-defined Attributes */ + /* IETF-defined Attributes */ ptr++; attr_type = EXTRACT_16BITS(ptr); ptr++; printf("%s", tok2str(l2tp_avp2str, "AVP-#%u", attr_type)); @@ -537,7 +566,7 @@ l2tp_avp_print(const u_char *dat, int length) case L2TP_AVP_CALLED_NUMBER: case L2TP_AVP_SUB_ADDRESS: case L2TP_AVP_PROXY_AUTH_NAME: - case L2TP_AVP_PRIVATE_GRP_ID: + case L2TP_AVP_PRIVATE_GRP_ID: print_string((u_char *)ptr, len-6); break; case L2TP_AVP_CHALLENGE: @@ -607,15 +636,15 @@ l2tp_avp_print(const u_char *dat, int length) void l2tp_print(const u_char *dat, u_int length) { - const u_int16_t *ptr = (u_int16_t *)dat; + const u_char *ptr = dat; u_int cnt = 0; /* total octets consumed */ u_int16_t pad; - int flag_t, flag_l, flag_s, flag_o, flag_p; + int flag_t, flag_l, flag_s, flag_o; u_int16_t l2tp_len; - flag_t = flag_l = flag_s = flag_o = flag_p = FALSE; + flag_t = flag_l = flag_s = flag_o = FALSE; - TCHECK(*ptr); /* Flags & Version */ + TCHECK2(*ptr, 2); /* Flags & Version */ if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) { printf(" l2tp:"); } else if ((EXTRACT_16BITS(ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) { @@ -643,55 +672,73 @@ l2tp_print(const u_char *dat, u_int length) flag_o = TRUE; printf("O"); } - if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY) { - flag_p = TRUE; + if (EXTRACT_16BITS(ptr) & L2TP_FLAG_PRIORITY) printf("P"); - } printf("]"); - ptr++; + ptr += 2; cnt += 2; - + if (flag_l) { - TCHECK(*ptr); /* Length */ - l2tp_len = EXTRACT_16BITS(ptr); ptr++; + TCHECK2(*ptr, 2); /* Length */ + l2tp_len = EXTRACT_16BITS(ptr); + ptr += 2; cnt += 2; } else { l2tp_len = 0; } - TCHECK(*ptr); /* Tunnel ID */ - printf("(%u/", EXTRACT_16BITS(ptr)); ptr++; + TCHECK2(*ptr, 2); /* Tunnel ID */ + printf("(%u/", EXTRACT_16BITS(ptr)); + ptr += 2; cnt += 2; - TCHECK(*ptr); /* Session ID */ - printf("%u)", EXTRACT_16BITS(ptr)); ptr++; + TCHECK2(*ptr, 2); /* Session ID */ + printf("%u)", EXTRACT_16BITS(ptr)); + ptr += 2; cnt += 2; if (flag_s) { - TCHECK(*ptr); /* Ns */ - printf("Ns=%u,", EXTRACT_16BITS(ptr)); ptr++; + TCHECK2(*ptr, 2); /* Ns */ + printf("Ns=%u,", EXTRACT_16BITS(ptr)); + ptr += 2; cnt += 2; - TCHECK(*ptr); /* Nr */ - printf("Nr=%u", EXTRACT_16BITS(ptr)); ptr++; + TCHECK2(*ptr, 2); /* Nr */ + printf("Nr=%u", EXTRACT_16BITS(ptr)); + ptr += 2; cnt += 2; } if (flag_o) { - TCHECK(*ptr); /* Offset Size */ - pad = EXTRACT_16BITS(ptr); ptr++; - ptr += pad / sizeof(*ptr); + TCHECK2(*ptr, 2); /* Offset Size */ + pad = EXTRACT_16BITS(ptr); + ptr += (2 + pad); cnt += (2 + pad); } + if (flag_l) { + if (length < l2tp_len) { + printf(" Length %u larger than packet", l2tp_len); + return; + } + length = l2tp_len; + } + if (length < cnt) { + printf(" Length %u smaller than header length", length); + return; + } if (flag_t) { + if (!flag_l) { + printf(" No length"); + return; + } if (length - cnt == 0) { printf(" ZLB"); } else { - l2tp_avp_print((u_char *)ptr, length - cnt); + l2tp_avp_print(ptr, length - cnt); } } else { printf(" {"); - ppp_print((u_char *)ptr, length - cnt); + ppp_print(ptr, length - cnt); printf("}"); } @@ -699,4 +746,4 @@ l2tp_print(const u_char *dat, u_int length) trunc: printf("%s", tstr); -} +}