*/
+/* \summary: Layer Two Tunneling Protocol (L2TP) printer */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
/* AVP-specific print out routines */
/***********************************/
static void
-l2tp_msgtype_print(netdissect_options *ndo, const u_char *dat)
+l2tp_msgtype_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint16_t *ptr = (const uint16_t *)dat;
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ND_PRINT((ndo, "%s", tok2str(l2tp_msgtype2str, "MSGTYPE-#%u",
EXTRACT_16BITS(ptr))));
}
{
const uint16_t *ptr = (const uint16_t *)dat;
- ND_PRINT((ndo, "%u", EXTRACT_16BITS(ptr))); ptr++; /* Result Code */
- if (length > 2) { /* Error Code (opt) */
- ND_PRINT((ndo, "/%u", EXTRACT_16BITS(ptr))); ptr++;
+ /* Result Code */
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
}
- if (length > 4) { /* Error Message (opt) */
- ND_PRINT((ndo, " "));
- print_string(ndo, (const u_char *)ptr, length - 4);
+ ND_PRINT((ndo, "%u", EXTRACT_16BITS(ptr)));
+ ptr++;
+ length -= 2;
+
+ /* Error Code (opt) */
+ if (length == 0)
+ return;
+ if (length < 2) {
+ ND_PRINT((ndo, " AVP too short"));
+ return;
}
+ ND_PRINT((ndo, "/%u", EXTRACT_16BITS(ptr)));
+ ptr++;
+ length -= 2;
+
+ /* Error Message (opt) */
+ if (length == 0)
+ return;
+ ND_PRINT((ndo, " "));
+ print_string(ndo, (const u_char *)ptr, length);
}
static void
-l2tp_proto_ver_print(netdissect_options *ndo, const uint16_t *dat)
+l2tp_proto_ver_print(netdissect_options *ndo, const uint16_t *dat, u_int length)
{
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ND_PRINT((ndo, "%u.%u", (EXTRACT_16BITS(dat) >> 8),
(EXTRACT_16BITS(dat) & 0xff)));
}
static void
-l2tp_framing_cap_print(netdissect_options *ndo, const u_char *dat)
+l2tp_framing_cap_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint32_t *ptr = (const uint32_t *)dat;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_CAP_ASYNC_MASK) {
ND_PRINT((ndo, "A"));
}
}
static void
-l2tp_bearer_cap_print(netdissect_options *ndo, const u_char *dat)
+l2tp_bearer_cap_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint32_t *ptr = (const uint32_t *)dat;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
if (EXTRACT_32BITS(ptr) & L2TP_BEARER_CAP_ANALOG_MASK) {
ND_PRINT((ndo, "A"));
}
static void
l2tp_q931_cc_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
+ if (length < 3) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
print_16bits_val(ndo, (const uint16_t *)dat);
ND_PRINT((ndo, ", %02x", dat[2]));
- if (length > 3) {
+ dat += 3;
+ length -= 3;
+ if (length != 0) {
ND_PRINT((ndo, " "));
- print_string(ndo, dat+3, length-3);
+ print_string(ndo, dat, length);
}
}
static void
-l2tp_bearer_type_print(netdissect_options *ndo, const u_char *dat)
+l2tp_bearer_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint32_t *ptr = (const uint32_t *)dat;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
if (EXTRACT_32BITS(ptr) & L2TP_BEARER_TYPE_ANALOG_MASK) {
ND_PRINT((ndo, "A"));
}
}
static void
-l2tp_framing_type_print(netdissect_options *ndo, const u_char *dat)
+l2tp_framing_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint32_t *ptr = (const uint32_t *)dat;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
if (EXTRACT_32BITS(ptr) & L2TP_FRAMING_TYPE_ASYNC_MASK) {
ND_PRINT((ndo, "A"));
}
}
static void
-l2tp_proxy_auth_type_print(netdissect_options *ndo, const u_char *dat)
+l2tp_proxy_auth_type_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint16_t *ptr = (const uint16_t *)dat;
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ND_PRINT((ndo, "%s", tok2str(l2tp_authentype2str,
"AuthType-#%u", EXTRACT_16BITS(ptr))));
}
static void
-l2tp_proxy_auth_id_print(netdissect_options *ndo, const u_char *dat)
+l2tp_proxy_auth_id_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint16_t *ptr = (const uint16_t *)dat;
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ND_PRINT((ndo, "%u", EXTRACT_16BITS(ptr) & L2TP_PROXY_AUTH_ID_MASK));
}
static void
-l2tp_call_errors_print(netdissect_options *ndo, const u_char *dat)
+l2tp_call_errors_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint16_t *ptr = (const uint16_t *)dat;
uint16_t val_h, val_l;
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ptr++; /* skip "Reserved" */
+ length -= 2;
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "CRCErr=%u ", (val_h<<16) + val_l));
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "FrameErr=%u ", (val_h<<16) + val_l));
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "HardOver=%u ", (val_h<<16) + val_l));
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "BufOver=%u ", (val_h<<16) + val_l));
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "Timeout=%u ", (val_h<<16) + val_l));
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
val_h = EXTRACT_16BITS(ptr); ptr++;
val_l = EXTRACT_16BITS(ptr); ptr++;
ND_PRINT((ndo, "AlignErr=%u ", (val_h<<16) + val_l));
}
static void
-l2tp_accm_print(netdissect_options *ndo, const u_char *dat)
+l2tp_accm_print(netdissect_options *ndo, const u_char *dat, u_int length)
{
const uint16_t *ptr = (const uint16_t *)dat;
uint16_t val_h, val_l;
+ if (length < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
ptr++; /* skip "Reserved" */
+ length -= 2;
- val_h = EXTRACT_16BITS(ptr); ptr++;
- val_l = EXTRACT_16BITS(ptr); ptr++;
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ val_h = EXTRACT_16BITS(ptr); ptr++; length -= 2;
+ val_l = EXTRACT_16BITS(ptr); ptr++; length -= 2;
ND_PRINT((ndo, "send=%08x ", (val_h<<16) + val_l));
+ if (length < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
val_h = EXTRACT_16BITS(ptr); ptr++;
val_l = EXTRACT_16BITS(ptr); ptr++;
ND_PRINT((ndo, "recv=%08x ", (val_h<<16) + val_l));
{
const uint16_t *ptr = (const uint16_t *)dat;
- ND_PRINT((ndo, "%04x, ", EXTRACT_16BITS(ptr))); ptr++; /* Disconnect Code */
- ND_PRINT((ndo, "%04x ", EXTRACT_16BITS(ptr))); ptr++; /* Control Protocol Number */
+ if (length < 5) {
+ ND_PRINT((ndo, "AVP too short"));
+ return;
+ }
+ /* Disconnect Code */
+ ND_PRINT((ndo, "%04x, ", EXTRACT_16BITS(dat)));
+ dat += 2;
+ length -= 2;
+ /* Control Protocol Number */
+ ND_PRINT((ndo, "%04x ", EXTRACT_16BITS(dat)));
+ dat += 2;
+ length -= 2;
+ /* Direction */
ND_PRINT((ndo, "%s", tok2str(l2tp_cc_direction2str,
- "Direction-#%u", *((const u_char *)ptr++))));
+ "Direction-#%u", EXTRACT_8BITS(ptr))));
+ ptr++;
+ length--;
- if (length > 5) {
+ if (length != 0) {
ND_PRINT((ndo, " "));
- print_string(ndo, (const u_char *)ptr, length-5);
+ print_string(ndo, (const u_char *)ptr, length);
}
}
/* If it goes past the end of the remaining length of the captured
data, we'll give up. */
ND_TCHECK2(*ptr, len);
- /* After this point, no need to worry about truncation */
+
+ /*
+ * After this point, we don't need to check whether we go past
+ * the length of the captured data; however, we *do* need to
+ * check whether we go past the end of the AVP.
+ */
if (EXTRACT_16BITS(ptr) & L2TP_AVP_HDR_FLAG_MANDATORY) {
ND_PRINT((ndo, "*"));
} else {
switch (attr_type) {
case L2TP_AVP_MSGTYPE:
- l2tp_msgtype_print(ndo, (const u_char *)ptr);
+ l2tp_msgtype_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_RESULT_CODE:
l2tp_result_code_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_PROTO_VER:
- l2tp_proto_ver_print(ndo, ptr);
+ l2tp_proto_ver_print(ndo, ptr, len-6);
break;
case L2TP_AVP_FRAMING_CAP:
- l2tp_framing_cap_print(ndo, (const u_char *)ptr);
+ l2tp_framing_cap_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_BEARER_CAP:
- l2tp_bearer_cap_print(ndo, (const u_char *)ptr);
+ l2tp_bearer_cap_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_TIE_BREAKER:
+ if (len-6 < 8) {
+ ND_PRINT((ndo, "AVP too short"));
+ break;
+ }
print_octets(ndo, (const u_char *)ptr, 8);
break;
case L2TP_AVP_FIRM_VER:
case L2TP_AVP_ASSND_TUN_ID:
case L2TP_AVP_RECV_WIN_SIZE:
case L2TP_AVP_ASSND_SESS_ID:
+ if (len-6 < 2) {
+ ND_PRINT((ndo, "AVP too short"));
+ break;
+ }
print_16bits_val(ndo, ptr);
break;
case L2TP_AVP_HOST_NAME:
l2tp_q931_cc_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_CHALLENGE_RESP:
+ if (len-6 < 16) {
+ ND_PRINT((ndo, "AVP too short"));
+ break;
+ }
print_octets(ndo, (const u_char *)ptr, 16);
break;
case L2TP_AVP_CALL_SER_NUM:
case L2TP_AVP_TX_CONN_SPEED:
case L2TP_AVP_PHY_CHANNEL_ID:
case L2TP_AVP_RX_CONN_SPEED:
+ if (len-6 < 4) {
+ ND_PRINT((ndo, "AVP too short"));
+ break;
+ }
print_32bits_val(ndo, (const uint32_t *)ptr);
break;
case L2TP_AVP_BEARER_TYPE:
- l2tp_bearer_type_print(ndo, (const u_char *)ptr);
+ l2tp_bearer_type_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_FRAMING_TYPE:
- l2tp_framing_type_print(ndo, (const u_char *)ptr);
+ l2tp_framing_type_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_PACKET_PROC_DELAY:
l2tp_packet_proc_delay_print(ndo);
break;
case L2TP_AVP_PROXY_AUTH_TYPE:
- l2tp_proxy_auth_type_print(ndo, (const u_char *)ptr);
+ l2tp_proxy_auth_type_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_PROXY_AUTH_ID:
- l2tp_proxy_auth_id_print(ndo, (const u_char *)ptr);
+ l2tp_proxy_auth_id_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_CALL_ERRORS:
- l2tp_call_errors_print(ndo, (const u_char *)ptr);
+ l2tp_call_errors_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_ACCM:
- l2tp_accm_print(ndo, (const u_char *)ptr);
+ l2tp_accm_print(ndo, (const u_char *)ptr, len-6);
break;
case L2TP_AVP_SEQ_REQUIRED:
break; /* No Attribute Value */
projects / tcpdump / blobdiff