* http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
*/
-#define NETDISSECT_REWORKED
+/* \summary: Cisco Discovery Protocol (CDP) printer */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
#include <string.h>
-#include "interface.h"
+#include "netdissect.h"
#include "addrtoname.h"
-#include "extract.h" /* must come after interface.h */
+#include "extract.h"
#include "nlpid.h"
static const char tstr[] = "[|cdp]";
-#define CDP_HEADER_LEN 4
+#define CDP_HEADER_LEN 4
+#define CDP_HEADER_VERSION_OFFSET 0
+#define CDP_HEADER_TTL_OFFSET 1
+#define CDP_HEADER_CHECKSUM_OFFSET 2
+
+#define CDP_TLV_HEADER_LEN 4
+#define CDP_TLV_TYPE_OFFSET 0
+#define CDP_TLV_LEN_OFFSET 2
static const struct tok cdp_tlv_values[] = {
{ 0x01, "Device-ID"},
const u_char *pptr, u_int length, u_int caplen)
{
int type, len, i, j;
- const u_char *tptr;
+ const u_char *tptr;
if (caplen < CDP_HEADER_LEN) {
ND_PRINT((ndo, "%s", tstr));
return;
}
- tptr = pptr; /* temporary pointer */
+ tptr = pptr; /* temporary pointer */
ND_TCHECK2(*tptr, CDP_HEADER_LEN);
- ND_PRINT((ndo, "CDPv%u, ttl: %us", *tptr, *(tptr + 1)));
+ ND_PRINT((ndo, "CDPv%u, ttl: %us", EXTRACT_U_1((tptr + CDP_HEADER_VERSION_OFFSET)),
+ EXTRACT_U_1(tptr + CDP_HEADER_TTL_OFFSET)));
if (ndo->ndo_vflag)
- ND_PRINT((ndo, ", checksum: %u (unverified), length %u", EXTRACT_16BITS(tptr), length));
+ ND_PRINT((ndo, ", checksum: 0x%04x (unverified), length %u", EXTRACT_BE_U_2(tptr + CDP_HEADER_CHECKSUM_OFFSET), length));
tptr += CDP_HEADER_LEN;
while (tptr < (pptr+length)) {
- ND_TCHECK2(*tptr, 4); /* read out Type and Length */
- type = EXTRACT_16BITS(tptr);
- len = EXTRACT_16BITS(tptr+2); /* object length includes the 4 bytes header length */
- tptr += 4;
- len -= 4;
+ ND_TCHECK2(*tptr, CDP_TLV_HEADER_LEN); /* read out Type and Length */
+ type = EXTRACT_BE_U_2(tptr + CDP_TLV_TYPE_OFFSET);
+ len = EXTRACT_BE_U_2(tptr + CDP_TLV_LEN_OFFSET); /* object length includes the 4 bytes header length */
+ if (len < CDP_TLV_HEADER_LEN) {
+ if (ndo->ndo_vflag)
+ ND_PRINT((ndo, "\n\t%s (0x%02x), TLV length: %u byte%s (too short)",
+ tok2str(cdp_tlv_values,"unknown field type", type),
+ type,
+ len,
+ PLURAL_SUFFIX(len))); /* plural */
+ else
+ ND_PRINT((ndo, ", %s TLV length %u too short",
+ tok2str(cdp_tlv_values,"unknown field type", type),
+ len));
+ break;
+ }
+ tptr += CDP_TLV_HEADER_LEN;
+ len -= CDP_TLV_HEADER_LEN;
ND_TCHECK2(*tptr, len);
- if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */
+ if (ndo->ndo_vflag || type == 1) { /* in non-verbose mode just print Device-ID */
- if (ndo->ndo_vflag)
- ND_PRINT((ndo, "\n\t%s (0x%02x), length: %u byte%s: ",
- tok2str(cdp_tlv_values,"unknown field type", type),
- type,
- len,
- PLURAL_SUFFIX(len))); /* plural */
+ if (ndo->ndo_vflag)
+ ND_PRINT((ndo, "\n\t%s (0x%02x), value length: %u byte%s: ",
+ tok2str(cdp_tlv_values,"unknown field type", type),
+ type,
+ len,
+ PLURAL_SUFFIX(len))); /* plural */
- switch (type) {
+ switch (type) {
- case 0x01: /* Device-ID */
- if (!ndo->ndo_vflag)
- ND_PRINT((ndo, ", Device-ID "));
- ND_PRINT((ndo, "'"));
- fn_printn(ndo, tptr, len, NULL);
- ND_PRINT((ndo, "'"));
+ case 0x01: /* Device-ID */
+ if (!ndo->ndo_vflag)
+ ND_PRINT((ndo, ", Device-ID "));
+ ND_PRINT((ndo, "'"));
+ (void)fn_printn(ndo, tptr, len, NULL);
+ ND_PRINT((ndo, "'"));
break;
- case 0x02: /* Address */
- if (cdp_print_addr(ndo, tptr, len) < 0)
- goto trunc;
+ case 0x02: /* Address */
+ if (cdp_print_addr(ndo, tptr, len) < 0)
+ goto trunc;
break;
- case 0x03: /* Port-ID */
- ND_PRINT((ndo, "'"));
- fn_printn(ndo, tptr, len, NULL);
- ND_PRINT((ndo, "'"));
+ case 0x03: /* Port-ID */
+ ND_PRINT((ndo, "'"));
+ (void)fn_printn(ndo, tptr, len, NULL);
+ ND_PRINT((ndo, "'"));
break;
- case 0x04: /* Capabilities */
+ case 0x04: /* Capabilities */
+ if (len < 4)
+ goto trunc;
ND_PRINT((ndo, "(0x%08x): %s",
- EXTRACT_32BITS(tptr),
- bittok2str(cdp_capability_values, "none", EXTRACT_32BITS(tptr))));
+ EXTRACT_BE_U_4(tptr),
+ bittok2str(cdp_capability_values, "none", EXTRACT_BE_U_4(tptr))));
break;
- case 0x05: /* Version */
- ND_PRINT((ndo, "\n\t "));
- for (i=0;i<len;i++) {
- j = *(tptr+i);
- ND_PRINT((ndo, "%c", j));
- if (j == 0x0a) /* lets rework the version string to get a nice identation */
- ND_PRINT((ndo, "\t "));
- }
+ case 0x05: /* Version */
+ ND_PRINT((ndo, "\n\t "));
+ for (i=0;i<len;i++) {
+ j = EXTRACT_U_1(tptr + i);
+ if (j == '\n') /* lets rework the version string to
+ get a nice indentation */
+ ND_PRINT((ndo, "\n\t "));
+ else
+ fn_print_char(ndo, j);
+ }
break;
- case 0x06: /* Platform */
- ND_PRINT((ndo, "'"));
- fn_printn(ndo, tptr, len, NULL);
- ND_PRINT((ndo, "'"));
+ case 0x06: /* Platform */
+ ND_PRINT((ndo, "'"));
+ (void)fn_printn(ndo, tptr, len, NULL);
+ ND_PRINT((ndo, "'"));
break;
- case 0x07: /* Prefixes */
+ case 0x07: /* Prefixes */
if (cdp_print_prefixes(ndo, tptr, len) < 0)
- goto trunc;
+ goto trunc;
break;
- case 0x08: /* Protocol Hello Option - not documented */
+ case 0x08: /* Protocol Hello Option - not documented */
break;
- case 0x09: /* VTP Mgmt Domain - not documented */
- ND_PRINT((ndo, "'"));
- fn_printn(ndo, tptr, len, NULL);
- ND_PRINT((ndo, "'"));
+ case 0x09: /* VTP Mgmt Domain - CDPv2 */
+ ND_PRINT((ndo, "'"));
+ (void)fn_printn(ndo, tptr, len, NULL);
+ ND_PRINT((ndo, "'"));
break;
- case 0x0a: /* Native VLAN ID - not documented */
- ND_PRINT((ndo, "%d", EXTRACT_16BITS(tptr)));
+ case 0x0a: /* Native VLAN ID - CDPv2 */
+ if (len < 2)
+ goto trunc;
+ ND_PRINT((ndo, "%d", EXTRACT_BE_U_2(tptr)));
break;
- case 0x0b: /* Duplex - not documented */
- ND_PRINT((ndo, "%s", *(tptr) ? "full": "half"));
+ case 0x0b: /* Duplex - CDPv2 */
+ if (len < 1)
+ goto trunc;
+ ND_PRINT((ndo, "%s", EXTRACT_U_1(tptr) ? "full": "half"));
break;
- /* http://www.cisco.com/univercd/cc/td/doc/product/voice/ata/atarn/186rn21m.htm
- * plus more details from other sources
- */
- case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
- ND_PRINT((ndo, "app %d, vlan %d", *(tptr), EXTRACT_16BITS(tptr + 1)));
+ /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html
+ * plus more details from other sources
+ */
+ case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */
+ if (len < 3)
+ goto trunc;
+ ND_PRINT((ndo, "app %d, vlan %d", EXTRACT_U_1((tptr)), EXTRACT_BE_U_2(tptr + 1)));
break;
- case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
+ case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */
ND_PRINT((ndo, "%1.2fW", cdp_get_number(tptr, len) / 1000.0));
break;
- case 0x11: /* MTU - not documented */
- ND_PRINT((ndo, "%u bytes", EXTRACT_32BITS(tptr)));
+ case 0x11: /* MTU - not documented */
+ if (len < 4)
+ goto trunc;
+ ND_PRINT((ndo, "%u bytes", EXTRACT_BE_U_4(tptr)));
break;
- case 0x12: /* AVVID trust bitmap - not documented */
- ND_PRINT((ndo, "0x%02x", *(tptr)));
+ case 0x12: /* AVVID trust bitmap - not documented */
+ if (len < 1)
+ goto trunc;
+ ND_PRINT((ndo, "0x%02x", EXTRACT_U_1(tptr)));
break;
- case 0x13: /* AVVID untrusted port CoS - not documented */
- ND_PRINT((ndo, "0x%02x", *(tptr)));
+ case 0x13: /* AVVID untrusted port CoS - not documented */
+ if (len < 1)
+ goto trunc;
+ ND_PRINT((ndo, "0x%02x", EXTRACT_U_1(tptr)));
break;
- case 0x14: /* System Name - not documented */
- ND_PRINT((ndo, "'"));
- fn_printn(ndo, tptr, len, NULL);
- ND_PRINT((ndo, "'"));
+ case 0x14: /* System Name - not documented */
+ ND_PRINT((ndo, "'"));
+ (void)fn_printn(ndo, tptr, len, NULL);
+ ND_PRINT((ndo, "'"));
break;
- case 0x16: /* System Object ID - not documented */
+ case 0x16: /* System Object ID - not documented */
if (cdp_print_addr(ndo, tptr, len) < 0)
goto trunc;
break;
- case 0x17: /* Physical Location - not documented */
- ND_PRINT((ndo, "0x%02x", *(tptr)));
+ case 0x17: /* Physical Location - not documented */
+ if (len < 1)
+ goto trunc;
+ ND_PRINT((ndo, "0x%02x", EXTRACT_U_1(tptr)));
if (len > 1) {
ND_PRINT((ndo, "/"));
- fn_printn(ndo, tptr + 1, len - 1, NULL);
- }
- break;
- default:
- print_unknown_data(ndo, tptr, "\n\t ", len);
+ (void)fn_printn(ndo, tptr + 1, len - 1, NULL);
+ }
break;
- }
- }
- /* avoid infinite loop */
- if (len == 0)
+ default:
+ print_unknown_data(ndo, tptr, "\n\t ", len);
break;
+ }
+ }
tptr = tptr+len;
}
- if (ndo->ndo_vflag < 1)
- ND_PRINT((ndo, ", length %u", caplen));
+ if (ndo->ndo_vflag < 1)
+ ND_PRINT((ndo, ", length %u", caplen));
return;
trunc:
static int
cdp_print_addr(netdissect_options *ndo,
- const u_char * p, int l)
+ const u_char * p, int l)
{
int pt, pl, al, num;
const u_char *endp = p + l;
-#ifdef INET6
static const u_char prot_ipv6[] = {
0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
};
-#endif
- ND_TCHECK2(*p, 2);
- num = EXTRACT_32BITS(p);
+ ND_TCHECK_4(p);
+ if (p + 4 > endp)
+ goto trunc;
+ num = EXTRACT_BE_U_4(p);
p += 4;
while (p < endp && num >= 0) {
- ND_TCHECK2(*p, 2);
+ ND_TCHECK_2(p);
if (p + 2 > endp)
goto trunc;
pt = p[0]; /* type of "protocol" field */
pl = p[1]; /* length of "protocol" field */
p += 2;
- ND_TCHECK2(p[pl], 2);
+ ND_TCHECK_2(p + pl);
if (p + pl + 2 > endp)
goto trunc;
- al = EXTRACT_16BITS(&p[pl]); /* address length */
+ al = EXTRACT_BE_U_2(p + pl); /* address length */
if (pt == PT_NLPID && pl == 1 && *p == NLPID_IP && al == 4) {
/*
*/
p += 3;
- ND_TCHECK2(*p, 4);
+ ND_TCHECK_4(p);
if (p + 4 > endp)
goto trunc;
ND_PRINT((ndo, "IPv4 (%u) %s", num, ipaddr_string(ndo, p)));
p += 4;
}
-#ifdef INET6
else if (pt == PT_IEEE_802_2 && pl == 8 &&
memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
/*
ND_PRINT((ndo, "IPv6 (%u) %s", num, ip6addr_string(ndo, p)));
p += al;
}
-#endif
else {
/*
* Generic case: just print raw data
ND_TCHECK2(*p, pl);
if (p + pl > endp)
goto trunc;
- ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", *(p - 2), pl));
- while (pl-- > 0)
- ND_PRINT((ndo, " %02x", *p++));
- ND_TCHECK2(*p, 2);
+ ND_PRINT((ndo, "pt=0x%02x, pl=%d, pb=", EXTRACT_U_1((p - 2)), pl));
+ while (pl-- > 0) {
+ ND_PRINT((ndo, " %02x", EXTRACT_U_1(p)));
+ p++;
+ }
+ ND_TCHECK_2(p);
if (p + 2 > endp)
goto trunc;
- al = (*p << 8) + *(p + 1);
ND_PRINT((ndo, ", al=%d, a=", al));
p += 2;
ND_TCHECK2(*p, al);
if (p + al > endp)
goto trunc;
- while (al-- > 0)
- ND_PRINT((ndo, " %02x", *p++));
+ while (al-- > 0) {
+ ND_PRINT((ndo, " %02x", EXTRACT_U_1(p)));
+ p++;
+ }
}
num--;
if (num)
static int
cdp_print_prefixes(netdissect_options *ndo,
- const u_char * p, int l)
+ const u_char * p, int l)
{
if (l % 5)
goto trunc;
ND_PRINT((ndo, " IPv4 Prefixes (%d):", l / 5));
while (l > 0) {
- ND_PRINT((ndo, " %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]));
+ ND_PRINT((ndo, " %u.%u.%u.%u/%u",
+ EXTRACT_U_1(p), EXTRACT_U_1(p + 1), EXTRACT_U_1(p + 2),
+ EXTRACT_U_1(p + 3), EXTRACT_U_1(p + 4)));
l -= 5;
p += 5;
}
unsigned long res=0;
while( l>0 )
{
- res = (res<<8) + *p;
+ res = (res<<8) + EXTRACT_U_1(p);
p++; l--;
}
return res;
projects / tcpdump / blobdiff