* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by Jason L. Wright
- * 4. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* 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)
*/
#ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
#endif
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
#include <string.h>
-#include "interface.h"
+#include "netdissect.h"
+#include "addrtostr.h"
#include "extract.h"
#include "ethertype.h"
-static const char tstr[] = "[|gre]";
#define GRE_CP 0x8000 /* checksum present */
#define GRE_RP 0x4000 /* routing present */
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 void gre_sre_print(netdissect_options *, u_int16_t, u_int8_t, u_int8_t, const u_char *, u_int);
-static void gre_sre_ip_print(netdissect_options *, u_int8_t, u_int8_t, const u_char *, u_int);
-static void gre_sre_asn_print(netdissect_options *, u_int8_t, u_int8_t, 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(netdissect_options *ndo, const u_char *bp, u_int length)
{
u_int len = length, vers;
- if (len < 2) {
- ND_PRINT((ndo, "%s", tstr));
- return;
- }
- vers = EXTRACT_16BITS(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;
+ ndo->ndo_protocol = "gre";
+ ND_TCHECK_2(bp);
+ if (len < 2)
+ goto trunc;
+ vers = EXTRACT_BE_U_2(bp) & GRE_VERS_MASK;
+ ND_PRINT("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;
- }
+ ND_PRINT(" ERROR: unknown-version");
+ break;
+ }
+ return;
+
+trunc:
+ nd_print_trunc(ndo);
+ return;
}
static void
gre_print_0(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);
- if (ndo->ndo_vflag)
- ND_PRINT((ndo, ", Flags [%s]",
- bittok2str(gre_flag_values,"none",flags)));
+ /* 16 bits ND_TCHECKed in gre_print() */
+ flags = EXTRACT_BE_U_2(bp);
+ if (ndo->ndo_vflag)
+ ND_PRINT(", 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 (ndo->ndo_vflag)
- ND_PRINT((ndo, ", sum 0x%x", EXTRACT_16BITS(bp)));
+ ND_PRINT(", sum 0x%x", EXTRACT_BE_U_2(bp));
bp += 2;
len -= 2;
+ ND_TCHECK_2(bp);
if (len < 2)
goto trunc;
- ND_PRINT((ndo, ", off 0x%x", EXTRACT_16BITS(bp)));
+ ND_PRINT(", 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;
- ND_PRINT((ndo, ", key=0x%x", EXTRACT_32BITS(bp)));
+ ND_PRINT(", 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;
- ND_PRINT((ndo, ", seq %u", EXTRACT_32BITS(bp)));
+ ND_PRINT(", 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(ndo, 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));
+ if (ndo->ndo_eflag)
+ ND_PRINT(", proto %s (0x%04x)",
+ tok2str(ethertype_values,"unknown",prot), prot);
- ND_PRINT((ndo, ", length %u",length));
+ ND_PRINT(", 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 */
+ if (ndo->ndo_vflag < 1)
+ ND_PRINT(": "); /* put in a colon as protocol demarc */
+ else
+ ND_PRINT("\n\t"); /* if verbose go multiline */
switch (prot) {
case ETHERTYPE_IP:
- ip_print(ndo, bp, len);
+ ip_print(ndo, bp, len);
break;
-#ifdef INET6
case ETHERTYPE_IPV6:
ip6_print(ndo, bp, len);
break;
-#endif
case ETHERTYPE_MPLS:
- mpls_print(bp, len);
+ mpls_print(ndo, bp, len);
break;
case ETHERTYPE_IPX:
- ipx_print(bp, len);
+ ipx_print(ndo, bp, len);
break;
case ETHERTYPE_ATALK:
- atalk_print(bp, len);
+ atalk_print(ndo, bp, len);
break;
case ETHERTYPE_GRE_ISO:
- isoclns_print(bp, len, len);
+ isoclns_print(ndo, bp, len);
break;
case ETHERTYPE_TEB:
- ether_print(ndo, bp, len, len, NULL, NULL);
+ ether_print(ndo, bp, len, ndo->ndo_snapend - bp, NULL, NULL);
break;
default:
- ND_PRINT((ndo, "gre-proto-0x%x", prot));
+ ND_PRINT("gre-proto-0x%x", prot);
}
return;
trunc:
- ND_PRINT((ndo, "%s", tstr));
+ nd_print_trunc(ndo);
}
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 (ndo->ndo_vflag)
- ND_PRINT((ndo, ", Flags [%s]",
- bittok2str(gre_flag_values,"none",flags)));
+ ND_PRINT(", 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_KP) {
- u_int32_t k;
+ uint32_t k;
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- k = EXTRACT_32BITS(bp);
- ND_PRINT((ndo, ", call %d", k & 0xffff));
+ k = EXTRACT_BE_U_4(bp);
+ ND_PRINT(", call %u", k & 0xffff);
len -= 4;
bp += 4;
}
if (flags & GRE_SP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- ND_PRINT((ndo, ", seq %u", EXTRACT_32BITS(bp)));
+ ND_PRINT(", seq %u", EXTRACT_BE_U_4(bp));
bp += 4;
len -= 4;
}
if (flags & GRE_AP) {
+ ND_TCHECK_4(bp);
if (len < 4)
goto trunc;
- ND_PRINT((ndo, ", ack %u", EXTRACT_32BITS(bp)));
+ ND_PRINT(", ack %u", EXTRACT_BE_U_4(bp));
bp += 4;
len -= 4;
}
if ((flags & GRE_SP) == 0)
- ND_PRINT((ndo, ", no-payload"));
+ ND_PRINT(", no-payload");
- if (ndo->ndo_eflag)
- ND_PRINT((ndo, ", proto %s (0x%04x)",
- tok2str(ethertype_values,"unknown",prot),
- prot));
+ if (ndo->ndo_eflag)
+ ND_PRINT(", proto %s (0x%04x)",
+ tok2str(ethertype_values,"unknown",prot), prot);
- ND_PRINT((ndo, ", length %u",length));
+ ND_PRINT(", length %u",length);
- if ((flags & GRE_SP) == 0)
- return;
+ 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 */
+ if (ndo->ndo_vflag < 1)
+ ND_PRINT(": "); /* put in a colon as protocol demarc */
+ else
+ ND_PRINT("\n\t"); /* if verbose go multiline */
switch (prot) {
case ETHERTYPE_PPP:
- ppp_print(bp, len);
+ ppp_print(ndo, bp, len);
break;
default:
- ND_PRINT((ndo, "gre-proto-0x%x", prot));
+ ND_PRINT("gre-proto-0x%x", prot);
break;
}
return;
trunc:
- ND_PRINT((ndo, "%s", tstr));
+ nd_print_trunc(ndo);
}
-static void
-gre_sre_print(netdissect_options *ndo, 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:
- ND_PRINT((ndo, ", (rtaf=ip"));
- gre_sre_ip_print(ndo, sreoff, srelen, bp, len);
- ND_PRINT((ndo, ") "));
+ ND_PRINT(", (rtaf=ip");
+ ret = gre_sre_ip_print(ndo, sreoff, srelen, bp, len);
+ ND_PRINT(")");
break;
case GRESRE_ASN:
- ND_PRINT((ndo, ", (rtaf=asn"));
- gre_sre_asn_print(ndo, sreoff, srelen, bp, len);
- ND_PRINT((ndo, ") "));
+ ND_PRINT(", (rtaf=asn");
+ ret = gre_sre_asn_print(ndo, sreoff, srelen, bp, len);
+ ND_PRINT(")");
break;
default:
- ND_PRINT((ndo, ", (rtaf=0x%x) ", af));
+ ND_PRINT(", (rtaf=0x%x)", af);
+ ret = 1;
}
+ return (ret);
}
-static void
-gre_sre_ip_print(netdissect_options *ndo, 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) {
- ND_PRINT((ndo, ", badoffset=%u", sreoff));
- return;
+ ND_PRINT(", badoffset=%u", sreoff);
+ return (1);
}
if (srelen & 3) {
- ND_PRINT((ndo, ", badlength=%u", srelen));
- return;
+ ND_PRINT(", badlength=%u", srelen);
+ return (1);
}
if (sreoff >= srelen) {
- ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen));
- return;
+ ND_PRINT(", badoff/len=%u/%u", sreoff, srelen);
+ return (1);
}
- for (;;) {
- if (len < 4 || srelen == 0)
- return;
+ while (srelen != 0) {
+ ND_TCHECK_4(bp);
+ if (len < 4)
+ return (0);
- memcpy(&a, bp, sizeof(a));
- ND_PRINT((ndo, " %s%s",
- ((bp - up) == sreoff) ? "*" : "",
- inet_ntoa(a)));
+ addrtostr(bp, buf, sizeof(buf));
+ ND_PRINT(" %s%s",
+ ((bp - up) == sreoff) ? "*" : "", buf);
bp += 4;
len -= 4;
srelen -= 4;
}
+ return (1);
+trunc:
+ return 0;
}
-static void
-gre_sre_asn_print(netdissect_options *ndo, 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) {
- ND_PRINT((ndo, ", badoffset=%u", sreoff));
- return;
+ ND_PRINT(", badoffset=%u", sreoff);
+ return (1);
}
if (srelen & 1) {
- ND_PRINT((ndo, ", badlength=%u", srelen));
- return;
+ ND_PRINT(", badlength=%u", srelen);
+ return (1);
}
if (sreoff >= srelen) {
- ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen));
- return;
+ ND_PRINT(", badoff/len=%u/%u", sreoff, srelen);
+ return (1);
}
- for (;;) {
- if (len < 2 || srelen == 0)
- return;
+ while (srelen != 0) {
+ ND_TCHECK_2(bp);
+ if (len < 2)
+ return (0);
- ND_PRINT((ndo, " %s%x",
- ((bp - up) == sreoff) ? "*" : "",
- EXTRACT_16BITS(bp)));
+ ND_PRINT(" %s%x",
+ ((bp - up) == sreoff) ? "*" : "", EXTRACT_BE_U_2(bp));
bp += 2;
len -= 2;
srelen -= 2;
}
+ return (1);
+trunc:
+ return 0;
}
projects / tcpdump / blobdiff