/* \summary: Bidirectional Forwarding Detection (BFD) printer */
+/* specification: RFC 5880 (for version 1) and RFC 5881 */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
*/
/*
- * Control packet, BFDv1, draft-ietf-bfd-base-02.txt
+ * Control packet, BFDv1, RFC 5880
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * |Vers | Diag |Sta|P|F|C|A|D|R| Detect Mult | Length |
+ * |Vers | Diag |Sta|P|F|C|A|D|M| Detect Mult | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | My Discriminator |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
uint8_t auth_type;
uint8_t auth_len;
uint8_t auth_data;
+ uint8_t dummy; /* minimun 4 bytes */
+};
+
+enum auth_type {
+ AUTH_PASSWORD = 1,
+ AUTH_MD5 = 2,
+ AUTH_MET_MD5 = 3,
+ AUTH_SHA1 = 4,
+ AUTH_MET_SHA1 = 5
};
static const struct tok bfd_v1_authentication_values[] = {
- { 0, "Reserved" },
- { 1, "Simple Password" },
- { 2, "Keyed MD5" },
- { 3, "Meticulous Keyed MD5" },
- { 4, "Keyed SHA1" },
- { 5, "Meticulous Keyed SHA1" },
+ { AUTH_PASSWORD, "Simple Password" },
+ { AUTH_MD5, "Keyed MD5" },
+ { AUTH_MET_MD5, "Meticulous Keyed MD5" },
+ { AUTH_SHA1, "Keyed SHA1" },
+ { AUTH_MET_SHA1, "Meticulous Keyed SHA1" },
{ 0, NULL }
};
-#define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
-#define BFD_EXTRACT_DIAG(x) ((x)&0x1f)
+enum auth_length {
+ AUTH_PASSWORD_FIELD_MIN_LEN = 4, /* header + password min: 3 + 1 */
+ AUTH_PASSWORD_FIELD_MAX_LEN = 19, /* header + password max: 3 + 16 */
+ AUTH_MD5_FIELD_LEN = 24,
+ AUTH_MD5_HASH_LEN = 16,
+ AUTH_SHA1_FIELD_LEN = 28,
+ AUTH_SHA1_HASH_LEN = 20
+};
+
+#define BFD_EXTRACT_VERSION(x) (((x)&0xe0)>>5)
+#define BFD_EXTRACT_DIAG(x) ((x)&0x1f)
static const struct tok bfd_port_values[] = {
{ BFD_CONTROL_PORT, "Control" },
{ 0, NULL }
};
-
static const struct tok bfd_diag_values[] = {
{ 0, "No Diagnostic" },
{ 1, "Control Detection Time Expired" },
};
static const struct tok bfd_v0_flag_values[] = {
- { 0x80, "I Hear You" },
- { 0x40, "Demand" },
- { 0x20, "Poll" },
- { 0x10, "Final" },
- { 0x08, "Reserved" },
- { 0x04, "Reserved" },
- { 0x02, "Reserved" },
- { 0x01, "Reserved" },
+ { 0x80, "I Hear You" },
+ { 0x40, "Demand" },
+ { 0x20, "Poll" },
+ { 0x10, "Final" },
+ { 0x08, "Reserved" },
+ { 0x04, "Reserved" },
+ { 0x02, "Reserved" },
+ { 0x01, "Reserved" },
{ 0, NULL }
};
{ 0x08, "Control Plane Independent" },
{ BFD_FLAG_AUTH, "Authentication Present" },
{ 0x02, "Demand" },
- { 0x01, "Reserved" },
+ { 0x01, "Multipoint" },
{ 0, NULL }
};
{ 0, NULL }
};
+static int
+auth_print(netdissect_options *ndo, register const u_char *pptr)
+{
+ const struct bfd_auth_header_t *bfd_auth_header;
+ int i;
+
+ pptr += sizeof (const struct bfd_header_t);
+ bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
+ ND_TCHECK(*bfd_auth_header);
+ ND_PRINT((ndo, "\n\tAuthentication: %s (%u), length: %u",
+ tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
+ bfd_auth_header->auth_type,
+ bfd_auth_header->auth_len));
+ pptr += 2;
+ ND_PRINT((ndo, "\n\t Auth Key ID: %d", *pptr));
+
+ switch(bfd_auth_header->auth_type) {
+ case AUTH_PASSWORD:
+/*
+ * Simple Password Authentication Section Format
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Auth Type | Auth Len | Auth Key ID | Password... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ if (bfd_auth_header->auth_len < AUTH_PASSWORD_FIELD_MIN_LEN ||
+ bfd_auth_header->auth_len > AUTH_PASSWORD_FIELD_MAX_LEN) {
+ ND_PRINT((ndo, "[invalid length %d]",
+ bfd_auth_header->auth_len));
+ break;
+ }
+ pptr++;
+ ND_PRINT((ndo, ", Password: "));
+ /* the length is equal to the password length plus three */
+ if (fn_printn(ndo, pptr, bfd_auth_header->auth_len - 3,
+ ndo->ndo_snapend))
+ goto trunc;
+ break;
+ case AUTH_MD5:
+ case AUTH_MET_MD5:
+/*
+ * Keyed MD5 and Meticulous Keyed MD5 Authentication Section Format
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Auth Type | Auth Len | Auth Key ID | Reserved |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Sequence Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Auth Key/Digest... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ if (bfd_auth_header->auth_len != AUTH_MD5_FIELD_LEN) {
+ ND_PRINT((ndo, "[invalid length %d]",
+ bfd_auth_header->auth_len));
+ break;
+ }
+ pptr += 2;
+ ND_TCHECK2(*pptr, 4);
+ ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr)));
+ pptr += 4;
+ ND_TCHECK2(*pptr, AUTH_MD5_HASH_LEN);
+ ND_PRINT((ndo, "\n\t Digest: "));
+ for(i = 0; i < AUTH_MD5_HASH_LEN; i++)
+ ND_PRINT((ndo, "%02x", pptr[i]));
+ break;
+ case AUTH_SHA1:
+ case AUTH_MET_SHA1:
+/*
+ * Keyed SHA1 and Meticulous Keyed SHA1 Authentication Section Format
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Auth Type | Auth Len | Auth Key ID | Reserved |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Sequence Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Auth Key/Hash... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ... |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+ if (bfd_auth_header->auth_len != AUTH_SHA1_FIELD_LEN) {
+ ND_PRINT((ndo, "[invalid length %d]",
+ bfd_auth_header->auth_len));
+ break;
+ }
+ pptr += 2;
+ ND_TCHECK2(*pptr, 4);
+ ND_PRINT((ndo, ", Sequence Number: 0x%08x", EXTRACT_32BITS(pptr)));
+ pptr += 4;
+ ND_TCHECK2(*pptr, AUTH_SHA1_HASH_LEN);
+ ND_PRINT((ndo, "\n\t Hash: "));
+ for(i = 0; i < AUTH_SHA1_HASH_LEN; i++)
+ ND_PRINT((ndo, "%02x", pptr[i]));
+ break;
+ }
+ return 0;
+
+trunc:
+ return 1;
+}
+
void
bfd_print(netdissect_options *ndo, register const u_char *pptr,
register u_int len, register u_int port)
{
const struct bfd_header_t *bfd_header;
- const struct bfd_auth_header_t *bfd_auth_header;
uint8_t version = 0;
bfd_header = (const struct bfd_header_t *)pptr;
ND_PRINT((ndo, "\n\t Required min Echo Interval: %4u ms", EXTRACT_32BITS(bfd_header->required_min_echo_interval)/1000));
if (bfd_header->flags & BFD_FLAG_AUTH) {
- pptr += sizeof (const struct bfd_header_t);
- bfd_auth_header = (const struct bfd_auth_header_t *)pptr;
- ND_TCHECK2(*bfd_auth_header, sizeof(const struct bfd_auth_header_t));
- ND_PRINT((ndo, "\n\t%s (%u) Authentication, length %u present",
- tok2str(bfd_v1_authentication_values,"Unknown",bfd_auth_header->auth_type),
- bfd_auth_header->auth_type,
- bfd_auth_header->auth_len));
+ if (auth_print(ndo, pptr))
+ goto trunc;
}
break;
projects / tcpdump / blobdiff