#ifndef lint
static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.5 2001-05-10 02:58:30 fenner Exp $";
+ "@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.11 2001-09-17 21:57:56 fenner Exp $";
#endif
#ifdef HAVE_CONFIG_H
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
-static void cdp_print_addr( const u_char * p, int l );
-static void cdp_print_prefixes( const u_char * p, int l );
+static int cdp_print_addr(const u_char *, int);
+static int cdp_print_prefixes(const u_char *, int);
void
cdp_print(const u_char *p, u_int length, u_int caplen,
const u_char *esrc, const u_char *edst)
{
- int i;
+ u_int i;
int type, len;
/* Cisco Discovery Protocol */
- if ( caplen < 4 ) {
+ if (caplen < 4) {
(void)printf("[|cdp]");
return;
}
- i=0; /* CDP data starts at offset 0 */
- printf ("CDP v%d, ttl=%ds", p[i], p[i+1] );
- i+=4; /* skip version, TTL and chksum */
+ i = 0; /* CDP data starts at offset 0 */
+ printf("CDP v%u, ttl=%us", p[i], p[i + 1]);
+ i += 4; /* skip version, TTL and chksum */
while (i < length) {
- if ( i+4 > caplen ) {
- printf("[|cdp]");
- return;
- }
- type = (p[i]<<8) + p[i+1];
- len = (p[i+2]<<8) + p[i+3];
+ if (i + 4 > caplen)
+ goto trunc;
+ type = (p[i] << 8) + p[i + 1];
+ len = (p[i + 2] << 8) + p[i + 3];
- if (vflag > 1)
- printf( "\n\t" );
+ if (vflag > 1)
+ printf("\n\t");
- if ( vflag )
- printf( " %02x/%02x", type, len );
+ if (vflag)
+ printf(" %02x/%02x", type, len);
- if ( i+len > caplen ) {
- printf("[|cdp]");
- return;
- }
-
- switch( type )
- {
- case 0x01:
- printf( " DevID '%.*s'", len-4, p+i+4 );
- break;
- case 0x02:
- printf( " Addr" );
- cdp_print_addr( p+i+4, len-4 );
- break;
- case 0x03:
- printf( " PortID '%.*s'", len-4, p+i+4 );
- break;
- case 0x04:
- printf( " CAP 0x%02x", (unsigned) p[i+7] );
- break;
- case 0x05:
- if ( vflag > 1 )
- printf( " Version:\n%.*s", len-4, p+i+4 );
- else
- printf( " Version: (suppressed)" );
- break;
- case 0x06:
- printf( " Platform: '%.*s'", len-4, p+i+4 );
- break;
- case 0x07:
- cdp_print_prefixes( p+i+4, len-4 );
- break;
- case 0x09: /* guess - not documented */
- printf( " VTP Management Domain: '%.*s'", len-4, p+i+4 );
- break;
- case 0x0a: /* guess - not documented */
- printf( " Native VLAN ID: %d", (p[i+4]<<8) + p[i+4+1] - 1 );
- break;
- case 0x0b: /* guess - not documented */
- printf( " Duplex: %s", p[i+4] ? "full": "half" );
- break;
- default:
- printf( " unknown field type %02x, len %d", type, len );
- }
-
- /* avoid infinite loop */
- if (len == 0)
- break;
- i+=len;
+ if (i + len > caplen)
+ goto trunc;
+
+ switch (type) {
+ case 0x00:
+ printf(" Goodbye");
+ break;
+ case 0x01:
+ printf(" DevID '%.*s'", len - 4, p + i + 4);
+ break;
+ case 0x02:
+ printf(" Addr");
+ if (cdp_print_addr(p + i + 4, len - 4) < 0)
+ goto trunc;
+ break;
+ case 0x03:
+ printf(" PortID '%.*s'", len - 4, p + i + 4);
+ break;
+ case 0x04:
+ printf(" CAP 0x%02x", (unsigned) p[i + 7]);
+ break;
+ case 0x05:
+ if (vflag > 1)
+ printf(" Version:\n%.*s", len - 4, p + i + 4);
+ else
+ printf(" Version: (suppressed)");
+ break;
+ case 0x06:
+ printf(" Platform: '%.*s'", len - 4, p + i + 4);
+ break;
+ case 0x07:
+ if (cdp_print_prefixes(p + i + 4, len - 4) < 0)
+ goto trunc;
+ break;
+ case 0x09: /* guess - not documented */
+ printf(" VTP Management Domain: '%.*s'", len - 4,
+ p + i + 4);
+ break;
+ case 0x0a: /* guess - not documented */
+ printf(" Native VLAN ID: %d",
+ (p[i + 4] << 8) + p[i + 4 + 1] - 1);
+ break;
+ case 0x0b: /* guess - not documented */
+ printf(" Duplex: %s", p[i + 4] ? "full": "half");
+ break;
+ default:
+ printf(" unknown field type %02x, len %d", type, len);
+ break;
+ }
+
+ /* avoid infinite loop */
+ if (len == 0)
+ break;
+ i += len;
}
+
+ return;
+
+trunc:
+ printf("[|cdp]");
}
-static void
-cdp_print_addr( const u_char * p, int l )
+/*
+ * Protocol type values.
+ *
+ * PT_NLPID means that the protocol type field contains an OSI NLPID.
+ *
+ * PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
+ * LLC header that specifies that the payload is for that protocol.
+ */
+#define PT_NLPID 1 /* OSI NLPID */
+#define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */
+
+static int
+cdp_print_addr(const u_char * p, int l)
{
- int pl, al, num;
- const u_char * endp = p+l;
-
- num = (p[0] << 24) + (p[1]<<16) + (p[2]<<8)+ p[3];
- p+=4;
-
- printf(" (%d): ", num );
-
- while( p < endp && num >= 0) {
- pl=*(p+1);
- p+=2;
-
- /* special case: IPv4, protocol type=0xcc, addr. length=4 */
- if ( pl == 1 && *p == 0xcc &&
- p[1] == 0 && p[2] == 4 ) {
- p+=3;
-
- printf( "IPv4 %d.%d.%d.%d ", p[0], p[1], p[2], p[3] );
- p+=4;
- } else { /* generic case: just print raw data */
- printf("pt=0x%02x, pl=%d, pb=", *(p-2), pl);
- while( pl-- > 0 )
- printf( " %02x", *p++);
- al=(*p << 8) + *(p+1);
- printf( ", al=%d, a=", al );
- p+=2;
- while( al-- > 0 )
- printf( " %02x", *p++);
+ int pt, pl, al, num;
+ const u_char *endp = p + l;
+#ifdef INET6
+ static u_char prot_ipv6[] = {
+ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
+ };
+#endif
+
+ num = EXTRACT_32BITS(p);
+ p += 4;
+
+ printf(" (%d): ", num);
+
+ while (p < endp && num >= 0) {
+ if (p + 2 > endp)
+ goto trunc;
+ pt = p[0]; /* type of "protocol" field */
+ pl = p[1]; /* length of "protocol" field */
+ p += 2;
+
+ if (p + pl + 2 > endp)
+ goto trunc;
+ al = EXTRACT_16BITS(&p[pl]); /* address length */
+
+ if (pt == PT_NLPID && pl == 1 && *p == 0xcc && al == 4) {
+ /*
+ * IPv4: protocol type = NLPID, protocol length = 1
+ * (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
+ * address length = 4
+ */
+ p += 3;
+
+ if (p + 4 > endp)
+ goto trunc;
+ printf("IPv4 %u.%u.%u.%u", p[0], p[1], p[2], p[3]);
+ p += 4;
+ }
+#ifdef INET6
+ else if (pt == PT_IEEE_802_2 && pl == 8 &&
+ memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
+ /*
+ * IPv6: protocol type = IEEE 802.2 header,
+ * protocol length = 8 (size of LLC+SNAP header),
+ * protocol = LLC+SNAP header with the IPv6
+ * Ethertype, address length = 16
+ */
+ p += 10;
+ if (p + al > endp)
+ goto trunc;
+
+ printf("IPv6 %s", ip6addr_string(p));
+ p += al;
+ }
+#endif
+ else {
+ /*
+ * Generic case: just print raw data
+ */
+ if (p + pl > endp)
+ goto trunc;
+ printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
+ while (pl-- > 0)
+ printf(" %02x", *p++);
+ if (p + 2 > endp)
+ goto trunc;
+ al = (*p << 8) + *(p + 1);
+ printf(", al=%d, a=", al);
+ p += 2;
+ if (p + al > endp)
+ goto trunc;
+ while (al-- > 0)
+ printf(" %02x", *p++);
}
- printf(" ");
num--;
+ if (num)
+ printf(" ");
}
+
+ return 0;
+
+trunc:
+ return -1;
}
-static void
-cdp_print_prefixes( const u_char * p, int l )
+static int
+cdp_print_prefixes(const u_char * p, int l)
{
- printf( " IPv4 Prefixes (%d):", l/5 );
+ if (l % 5)
+ goto trunc;
+
+ printf(" IPv4 Prefixes (%d):", l / 5);
+
+ while (l > 0) {
+ printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
+ l -= 5;
+ p += 5;
+ }
+
+ return 0;
- while(l > 0) {
- printf( " %d.%d.%d.%d/%d", p[0], p[1], p[2], p[3], p[4] );
- l-=5; p+=5;
- }
+trunc:
+ return -1;
}
projects / tcpdump / blobdiff