X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/b751376719cfe1924aa07ab8fd364ec1a55c04b3..d2777156522f139a858bd6b5b51e364826bc95a7:/print-ip.c

diff --git a/print-ip.c b/print-ip.c
index 9e26d842..23ba99c9 100644
--- a/print-ip.c
+++ b/print-ip.c
@@ -27,8 +27,6 @@
 
 #include "netdissect-stdinc.h"
 
-#include <string.h>
-
 #include "netdissect.h"
 #include "addrtoname.h"
 #include "extract.h"
@@ -66,13 +64,12 @@ ip_printroute(netdissect_options *ndo,
 	}
 	if ((length + 1) & 3)
 		ND_PRINT(" [bad length %u]", length);
-	ND_TCHECK_1(cp + 2);
 	ptr = GET_U_1(cp + 2) - 1;
 	if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
 		ND_PRINT(" [bad ptr %u]", GET_U_1(cp + 2));
 
 	for (len = 3; len < length; len += 4) {
-		ND_TCHECK_4(cp + len);
+		ND_TCHECK_4(cp + len);	/* Needed to print the IP addresses */
 		ND_PRINT(" %s", GET_IPADDR_STRING(cp + len));
 		if (ptr > len)
 			ND_PRINT(",");
@@ -107,14 +104,12 @@ ip_finddst(netdissect_options *ndo,
 	for (; length != 0; cp += len, length -= len) {
 		int tt;
 
-		ND_TCHECK_1(cp);
 		tt = GET_U_1(cp);
 		if (tt == IPOPT_EOL)
 			break;
 		else if (tt == IPOPT_NOP)
 			len = 1;
 		else {
-			ND_TCHECK_1(cp + 1);
 			len = GET_U_1(cp + 1);
 			if (len < 2)
 				break;
@@ -183,16 +178,13 @@ ip_printts(netdissect_options *ndo,
 		return (0);
 	}
 	ND_PRINT(" TS{");
-	ND_TCHECK_1(cp + 3);
 	hoplen = ((GET_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
 	if ((length - 4) & (hoplen-1))
 		ND_PRINT("[bad length %u]", length);
-	ND_TCHECK_1(cp + 2);
 	ptr = GET_U_1(cp + 2) - 1;
 	len = 0;
 	if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
 		ND_PRINT("[bad ptr %u]", GET_U_1(cp + 2));
-	ND_TCHECK_1(cp + 3);
 	switch (GET_U_1(cp + 3)&0xF) {
 	case IPOPT_TS_TSONLY:
 		ND_PRINT("TSONLY");
@@ -200,16 +192,7 @@ ip_printts(netdissect_options *ndo,
 	case IPOPT_TS_TSANDADDR:
 		ND_PRINT("TS+ADDR");
 		break;
-	/*
-	 * prespecified should really be 3, but some ones might send 2
-	 * instead, and the IPOPT_TS_PRESPEC constant can apparently
-	 * have both values, so we have to hard-code it here.
-	 */
-
-	case 2:
-		ND_PRINT("PRESPEC2.0");
-		break;
-	case 3:			/* IPOPT_TS_PRESPEC */
+	case IPOPT_TS_PRESPEC:
 		ND_PRINT("PRESPEC");
 		break;
 	default:
@@ -257,7 +240,6 @@ ip_optprint(netdissect_options *ndo,
 		ND_PRINT("%s", sep);
 		sep = ",";
 
-		ND_TCHECK_1(cp);
 		option_code = GET_U_1(cp);
 
 		ND_PRINT("%s",
@@ -268,7 +250,6 @@ ip_optprint(netdissect_options *ndo,
 			option_len = 1;
 
 		else {
-			ND_TCHECK_1(cp + 1);
 			option_len = GET_U_1(cp + 1);
 			if (option_len < 2) {
 				ND_PRINT(" [bad length %u]", option_len);
@@ -396,7 +377,10 @@ ip_print(netdissect_options *ndo,
 	/*
 	 * Cut off the snapshot length to the end of the IP payload.
 	 */
-	nd_push_snapend(ndo, bp + len);
+	if (!nd_push_snaplen(ndo, bp, len)) {
+		(*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
+			"%s: can't push snaplen on buffer stack", __func__);
+	}
 
 	len -= hlen;
 
@@ -490,8 +474,18 @@ ip_print(netdissect_options *ndo,
 				     GET_IPADDR_STRING(ip->ip_src),
 				     GET_IPADDR_STRING(ip->ip_dst));
 		}
+		/*
+		 * Do a bounds check before calling ip_demux_print().
+		 * At least the header data is required.
+		 */
+		if (!ND_TTEST_LEN((const u_char *)ip, hlen)) {
+			ND_PRINT(" [remaining caplen(%u) < header length(%u)]",
+				 ND_BYTES_AVAILABLE_AFTER((const u_char *)ip),
+				 hlen);
+			nd_trunc_longjmp(ndo);
+		}
 		ip_demux_print(ndo, (const u_char *)ip + hlen, len, 4,
-		    off & IP_MF, GET_U_1(ip->ip_ttl), nh, bp);
+			       off & IP_MF, GET_U_1(ip->ip_ttl), nh, bp);
 	} else {
 		/*
 		 * Ultra quiet now means that all this stuff should be
@@ -519,7 +513,6 @@ ip_print(netdissect_options *ndo,
 
 trunc:
 	nd_print_trunc(ndo);
-	return;
 }
 
 void
@@ -531,7 +524,6 @@ ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
 		return;
 	}
 
-	ND_TCHECK_1(bp);
 	switch (GET_U_1(bp) & 0xF0) {
 	case 0x40:
 		ip_print(ndo, bp, length);
@@ -543,9 +535,4 @@ ipN_print(netdissect_options *ndo, const u_char *bp, u_int length)
 		ND_PRINT("unknown ip %u", (GET_U_1(bp) & 0xF0) >> 4);
 		break;
 	}
-	return;
-
-trunc:
-	nd_print_trunc(ndo);
-	return;
 }