X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/ed85e20e4d6a27d5405f37366dd34b64c10a9211..a9c8816ff092f73c15a9f16ba665e158da99a1a0:/print-gre.c

diff --git a/print-gre.c b/print-gre.c
index 604a9696..f363f8b1 100644
--- a/print-gre.c
+++ b/print-gre.c
@@ -12,11 +12,6 @@
  * 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
@@ -31,25 +26,26 @@
  * 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)
  */
 
-#define NETDISSECT_REWORKED
 #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 */
@@ -78,33 +74,38 @@ static const struct tok gre_flag_values[] = {
 
 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 *, uint16_t, uint8_t, uint8_t, const u_char *, u_int);
-static void gre_sre_ip_print(netdissect_options *, uint8_t, uint8_t, const u_char *, u_int);
-static void gre_sre_asn_print(netdissect_options *, uint8_t, uint8_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
@@ -113,47 +114,53 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
 	u_int len = length;
 	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;
 	}
@@ -164,18 +171,20 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
 			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;
@@ -184,27 +193,24 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
 		}
 	}
 
-        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(ndo, bp, len);
 		break;
@@ -215,18 +221,18 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
 		atalk_print(ndo, bp, len);
 		break;
 	case ETHERTYPE_GRE_ISO:
-		isoclns_print(ndo, 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
@@ -235,17 +241,19 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
 	u_int len = length;
 	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;
 
@@ -253,146 +261,158 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
 	if (flags & GRE_KP) {
 		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(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
+static int
 gre_sre_print(netdissect_options *ndo, uint16_t af, uint8_t sreoff,
-    uint8_t srelen, const u_char *bp, u_int len)
+	      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
+static int
 gre_sre_ip_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen,
-                 const u_char *bp, u_int len)
+		 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
+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 *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;
 }