* POSSIBILITY OF SUCH DAMAGE.
*/
+/* \summary: Generic Routing Encapsulation (GRE) printer */
+
/*
- * tcpdump filter for GRE - Generic Routing Encapsulation
+ * netdissect printer for GRE - Generic Routing Encapsulation
* RFC1701 (GRE), RFC1702 (GRE IPv4), and RFC2637 (Enhanced GRE)
*/
-#ifndef lint
-static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/tcpdump/print-gre.c,v 1.22 2003-05-22 16:52:37 hannes Exp $ (LBL)";
-#endif
-
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
-#include <stdio.h>
#include <string.h>
-#include "interface.h"
-#include "addrtoname.h"
+#include "netdissect.h"
+#include "addrtostr.h"
#include "extract.h"
+#include "ethertype.h"
-#include "ip.h"
+static const char tstr[] = "[|gre]";
#define GRE_CP 0x8000 /* checksum present */
#define GRE_RP 0x4000 /* routing present */
#define GRE_sP 0x0800 /* source routing */
#define GRE_RECRS 0x0700 /* recursion count */
#define GRE_AP 0x0080 /* acknowledgment# present */
-#define GRE_VERS 0x0007 /* protocol version */
-#define GREPROTO_IP 0x0800 /* IP */
-#define GREPROTO_PPP 0x880b /* PPTP */
-#define GREPROTO_ISO 0x00fe /* OSI */
+static const struct tok gre_flag_values[] = {
+ { GRE_CP, "checksum present"},
+ { GRE_RP, "routing present"},
+ { GRE_KP, "key present"},
+ { GRE_SP, "sequence# present"},
+ { GRE_sP, "source routing present"},
+ { GRE_RECRS, "recursion count"},
+ { GRE_AP, "ack present"},
+ { 0, NULL }
+};
+
+#define GRE_VERS_MASK 0x0007 /* protocol version */
/* source route entry types */
#define GRESRE_IP 0x0800 /* IP */
#define GRESRE_ASN 0xfffe /* ASN */
-void gre_print_0(const u_char *, u_int);
-void gre_print_1(const u_char *, u_int);
-void gre_sre_print(u_int16_t, u_int8_t, u_int8_t, const u_char *, u_int);
-void gre_sre_ip_print(u_int8_t, u_int8_t, const u_char *, u_int);
-void gre_sre_asn_print(u_int8_t, u_int8_t, const u_char *, u_int);
+static void gre_print_0(netdissect_options *, const u_char *, u_int);
+static void gre_print_1(netdissect_options *, const u_char *, u_int);
+static int gre_sre_print(netdissect_options *, uint16_t, uint8_t, uint8_t, const u_char *, u_int);
+static int gre_sre_ip_print(netdissect_options *, uint8_t, uint8_t, const u_char *, u_int);
+static int gre_sre_asn_print(netdissect_options *, uint8_t, uint8_t, const u_char *, u_int);
void
-gre_print(const u_char *bp, u_int length)
+gre_print(netdissect_options *ndo, const u_char *bp, u_int length)
{
u_int len = length, vers;
- if (len < 2) {
- printf("[|gre]");
- return;
- }
- vers = EXTRACT_16BITS(bp) & 7;
-
- if (vers == 0)
- gre_print_0(bp, len);
- else if (vers == 1)
- gre_print_1(bp, len);
- else
- printf("gre-unknown-version=%u", vers);
- return;
+ ND_TCHECK_2(bp);
+ if (len < 2)
+ goto trunc;
+ vers = EXTRACT_BE_U_2(bp) & GRE_VERS_MASK;
+ ND_PRINT((ndo, "GREv%u",vers));
+
+ switch(vers) {
+ case 0:
+ gre_print_0(ndo, bp, len);
+ break;
+ case 1:
+ gre_print_1(ndo, bp, len);
+ break;
+ default:
+ ND_PRINT((ndo, " ERROR: unknown-version"));
+ break;
+ }
+ return;
+trunc:
+ ND_PRINT((ndo, "%s", tstr));
+ return;
}
-void
-gre_print_0(const u_char *bp, u_int length)
+static void
+gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
{
u_int len = length;
- u_int16_t flags, prot;
-
- flags = EXTRACT_16BITS(bp);
- if (vflag) {
- printf("[%s%s%s%s%s] ",
- (flags & GRE_CP) ? "C" : "",
- (flags & GRE_RP) ? "R" : "",
- (flags & GRE_KP) ? "K" : "",
- (flags & GRE_SP) ? "S" : "",
- (flags & GRE_sP) ? "s" : "");
- }
+ uint16_t flags, prot;
+
+ /* 16 bits ND_TCHECKed in gre_print() */
+ flags = EXTRACT_BE_U_2(bp);
+ if (ndo->ndo_vflag)
+ ND_PRINT((ndo, ", Flags [%s]",
+ bittok2str(gre_flag_values,"none",flags)));
len -= 2;
bp += 2;
+ ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
- prot = EXTRACT_16BITS(bp);
+ prot = EXTRACT_BE_U_2(bp);
len -= 2;
bp += 2;
if ((flags & GRE_CP) | (flags & GRE_RP)) {
+ ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
- if (vflag)
- printf("sum 0x%x ", EXTRACT_16BITS(bp));
+ if (ndo->ndo_vflag)
+ ND_PRINT((ndo, ", sum 0x%x", EXTRACT_BE_U_2(bp)));
bp += 2;
len -= 2;
+ ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
- printf("off 0x%x ", EXTRACT_16BITS(bp));
+ ND_PRINT((ndo, ", off 0x%x", EXTRACT_BE_U_2(bp)));
bp += 2;
len -= 2;
}
if (flags & GRE_KP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- printf("key=0x%x ", EXTRACT_32BITS(bp));
+ ND_PRINT((ndo, ", key=0x%x", EXTRACT_BE_U_4(bp)));
bp += 4;
len -= 4;
}
if (flags & GRE_SP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- printf("seq %u ", EXTRACT_32BITS(bp));
+ ND_PRINT((ndo, ", seq %u", EXTRACT_BE_U_4(bp)));
bp += 4;
len -= 4;
}
if (flags & GRE_RP) {
for (;;) {
- u_int16_t af;
- u_int8_t sreoff;
- u_int8_t srelen;
+ uint16_t af;
+ uint8_t sreoff;
+ uint8_t srelen;
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- af = EXTRACT_16BITS(bp);
- sreoff = *(bp + 2);
- srelen = *(bp + 3);
+ af = EXTRACT_BE_U_2(bp);
+ sreoff = EXTRACT_U_1(bp + 2);
+ srelen = EXTRACT_U_1(bp + 3);
bp += 4;
len -= 4;
if (af == 0 && srelen == 0)
break;
- gre_sre_print(af, sreoff, srelen, bp, len);
+ if (!gre_sre_print(ndo, af, sreoff, srelen, bp, len))
+ goto trunc;
if (len < srelen)
goto trunc;
}
}
+ if (ndo->ndo_eflag)
+ ND_PRINT((ndo, ", proto %s (0x%04x)",
+ tok2str(ethertype_values,"unknown",prot),
+ prot));
+
+ ND_PRINT((ndo, ", length %u",length));
+
+ if (ndo->ndo_vflag < 1)
+ ND_PRINT((ndo, ": ")); /* put in a colon as protocol demarc */
+ else
+ ND_PRINT((ndo, "\n\t")); /* if verbose go multiline */
+
switch (prot) {
- case GREPROTO_IP:
- ip_print(bp, len);
+ case ETHERTYPE_IP:
+ ip_print(ndo, bp, len);
+ break;
+ case ETHERTYPE_IPV6:
+ ip6_print(ndo, bp, len);
+ break;
+ case ETHERTYPE_MPLS:
+ mpls_print(ndo, bp, len);
+ break;
+ case ETHERTYPE_IPX:
+ ipx_print(ndo, bp, len);
+ break;
+ case ETHERTYPE_ATALK:
+ atalk_print(ndo, bp, len);
break;
- case GREPROTO_ISO:
- isoclns_print(bp, len, len);
+ case ETHERTYPE_GRE_ISO:
+ isoclns_print(ndo, bp, len);
+ break;
+ case ETHERTYPE_TEB:
+ ether_print(ndo, bp, len, ndo->ndo_snapend - bp, NULL, NULL);
break;
default:
- printf("gre-proto-0x%x", prot);
+ ND_PRINT((ndo, "gre-proto-0x%x", prot));
}
return;
trunc:
- printf("[|gre]");
+ ND_PRINT((ndo, "%s", tstr));
}
-void
-gre_print_1(const u_char *bp, u_int length)
+static void
+gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
{
u_int len = length;
- u_int16_t flags, prot;
+ uint16_t flags, prot;
- flags = EXTRACT_16BITS(bp);
+ /* 16 bits ND_TCHECKed in gre_print() */
+ flags = EXTRACT_BE_U_2(bp);
len -= 2;
bp += 2;
- if (vflag) {
- printf("[%s%s%s%s%s%s] ",
- (flags & GRE_CP) ? "C" : "",
- (flags & GRE_RP) ? "R" : "",
- (flags & GRE_KP) ? "K" : "",
- (flags & GRE_SP) ? "S" : "",
- (flags & GRE_sP) ? "s" : "",
- (flags & GRE_AP) ? "A" : "");
- }
+ if (ndo->ndo_vflag)
+ ND_PRINT((ndo, ", Flags [%s]",
+ bittok2str(gre_flag_values,"none",flags)));
+ ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
- prot = EXTRACT_16BITS(bp);
+ prot = EXTRACT_BE_U_2(bp);
len -= 2;
bp += 2;
- if (flags & GRE_CP) {
- printf("cpset!");
- return;
- }
- if (flags & GRE_RP) {
- printf("rpset!");
- return;
- }
- if ((flags & GRE_KP) == 0) {
- printf("kpunset!");
- return;
- }
- if (flags & GRE_sP) {
- printf("spset!");
- return;
- }
if (flags & GRE_KP) {
- u_int32_t k;
+ uint32_t k;
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- k = EXTRACT_32BITS(bp);
- printf("call %d ", k & 0xffff);
+ k = EXTRACT_BE_U_4(bp);
+ ND_PRINT((ndo, ", call %d", k & 0xffff));
len -= 4;
bp += 4;
}
if (flags & GRE_SP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- printf("seq %u ", EXTRACT_32BITS(bp));
+ ND_PRINT((ndo, ", seq %u", EXTRACT_BE_U_4(bp)));
bp += 4;
len -= 4;
}
if (flags & GRE_AP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- printf("ack %u ", EXTRACT_32BITS(bp));
+ ND_PRINT((ndo, ", ack %u", EXTRACT_BE_U_4(bp)));
bp += 4;
len -= 4;
}
- if ((flags & GRE_SP) == 0) {
- printf("no-payload");
- return;
- }
+ if ((flags & GRE_SP) == 0)
+ ND_PRINT((ndo, ", no-payload"));
+
+ if (ndo->ndo_eflag)
+ ND_PRINT((ndo, ", proto %s (0x%04x)",
+ tok2str(ethertype_values,"unknown",prot),
+ prot));
+
+ ND_PRINT((ndo, ", length %u",length));
+
+ if ((flags & GRE_SP) == 0)
+ return;
+
+ if (ndo->ndo_vflag < 1)
+ ND_PRINT((ndo, ": ")); /* put in a colon as protocol demarc */
+ else
+ ND_PRINT((ndo, "\n\t")); /* if verbose go multiline */
switch (prot) {
- case GREPROTO_PPP:
- printf("gre-ppp-payload");
+ case ETHERTYPE_PPP:
+ ppp_print(ndo, bp, len);
break;
default:
- printf("gre-proto-0x%x", prot);
+ ND_PRINT((ndo, "gre-proto-0x%x", prot));
break;
}
return;
trunc:
- printf("[|gre]");
+ ND_PRINT((ndo, "%s", tstr));
}
-void
-gre_sre_print(u_int16_t af, u_int8_t sreoff, u_int8_t srelen,
- const u_char *bp, u_int len)
+static int
+gre_sre_print(netdissect_options *ndo, uint16_t af, uint8_t sreoff,
+ uint8_t srelen, const u_char *bp, u_int len)
{
+ int ret;
+
switch (af) {
case GRESRE_IP:
- printf("(rtaf=ip");
- gre_sre_ip_print(sreoff, srelen, bp, len);
- printf(") ");
+ ND_PRINT((ndo, ", (rtaf=ip"));
+ ret = gre_sre_ip_print(ndo, sreoff, srelen, bp, len);
+ ND_PRINT((ndo, ")"));
break;
case GRESRE_ASN:
- printf("(rtaf=asn");
- gre_sre_asn_print(sreoff, srelen, bp, len);
- printf(") ");
+ ND_PRINT((ndo, ", (rtaf=asn"));
+ ret = gre_sre_asn_print(ndo, sreoff, srelen, bp, len);
+ ND_PRINT((ndo, ")"));
break;
default:
- printf("(rtaf=0x%x) ", af);
+ ND_PRINT((ndo, ", (rtaf=0x%x)", af));
+ ret = 1;
}
+ return (ret);
}
-void
-gre_sre_ip_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
+
+static int
+gre_sre_ip_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen,
+ const u_char *bp, u_int len)
{
- struct in_addr a;
const u_char *up = bp;
+ char buf[INET_ADDRSTRLEN];
if (sreoff & 3) {
- printf(" badoffset=%u", sreoff);
- return;
+ ND_PRINT((ndo, ", badoffset=%u", sreoff));
+ return (1);
}
if (srelen & 3) {
- printf(" badlength=%u", srelen);
- return;
+ ND_PRINT((ndo, ", badlength=%u", srelen));
+ return (1);
}
if (sreoff >= srelen) {
- printf(" badoff/len=%u/%u", sreoff, srelen);
- return;
+ ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen));
+ return (1);
}
- for (;;) {
- if (len < 4 || srelen == 0)
- return;
+ while (srelen != 0) {
+ if (!ND_TTEST_4(bp))
+ return (0);
+ if (len < 4)
+ return (0);
- memcpy(&a, bp, sizeof(a));
- printf(" %s%s",
- ((bp - up) == sreoff) ? "*" : "",
- inet_ntoa(a));
+ addrtostr(bp, buf, sizeof(buf));
+ ND_PRINT((ndo, " %s%s",
+ ((bp - up) == sreoff) ? "*" : "", buf));
bp += 4;
len -= 4;
srelen -= 4;
}
+ return (1);
}
-void
-gre_sre_asn_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len)
+static int
+gre_sre_asn_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen,
+ const u_char *bp, u_int len)
{
const u_char *up = bp;
if (sreoff & 1) {
- printf(" badoffset=%u", sreoff);
- return;
+ ND_PRINT((ndo, ", badoffset=%u", sreoff));
+ return (1);
}
if (srelen & 1) {
- printf(" badlength=%u", srelen);
- return;
+ ND_PRINT((ndo, ", badlength=%u", srelen));
+ return (1);
}
if (sreoff >= srelen) {
- printf(" badoff/len=%u/%u", sreoff, srelen);
- return;
+ ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen));
+ return (1);
}
- for (;;) {
- if (len < 2 || srelen == 0)
- return;
+ while (srelen != 0) {
+ if (!ND_TTEST_2(bp))
+ return (0);
+ if (len < 2)
+ return (0);
- printf(" %s%x",
+ ND_PRINT((ndo, " %s%x",
((bp - up) == sreoff) ? "*" : "",
- EXTRACT_16BITS(bp));
+ EXTRACT_BE_U_2(bp)));
bp += 2;
len -= 2;
srelen -= 2;
}
+ return (1);
}
projects / tcpdump / blobdiff