X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/99c91c3aec40b691641374f58e798bd8d6b657bd..ebb51ef0e725737ca8c1d618da6527a58660d2bf:/print-sl.c

diff --git a/print-sl.c b/print-sl.c
index b69a07d5..a02077b3 100644
--- a/print-sl.c
+++ b/print-sl.c
@@ -19,6 +19,8 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: Compressed Serial Line Internet Protocol printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
@@ -66,6 +68,7 @@ sl_if_print(netdissect_options *ndo,
 		return (caplen);
 	}
 
+	caplen -= SLIP_HDRLEN;
 	length -= SLIP_HDRLEN;
 
 	ip = (const struct ip *)(p + SLIP_HDRLEN);
@@ -73,6 +76,11 @@ sl_if_print(netdissect_options *ndo,
 	if (ndo->ndo_eflag)
 		sliplink_print(ndo, p, ip, length);
 
+	if (caplen < 1 || length < 1) {
+		ND_PRINT((ndo, "%s", tstr));
+		return (caplen + SLIP_HDRLEN);
+	}
+
 	switch (IP_V(ip)) {
 	case 4:
 	        ip_print(ndo, (const u_char *)ip, length);
@@ -123,8 +131,21 @@ sliplink_print(netdissect_options *ndo,
 	u_int hlen;
 
 	dir = p[SLX_DIR];
-	ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O "));
+	switch (dir) {
 
+	case SLIPDIR_IN:
+		ND_PRINT((ndo, "I "));
+		break;
+
+	case SLIPDIR_OUT:
+		ND_PRINT((ndo, "O "));
+		break;
+
+	default:
+		ND_PRINT((ndo, "Invalid direction %d ", dir));
+		dir = -1;
+		break;
+	}
 	if (ndo->ndo_nflag) {
 		/* XXX just dump the header */
 		register int i;
@@ -147,13 +168,21 @@ sliplink_print(netdissect_options *ndo,
 		 * has restored the IP header copy to IPPROTO_TCP.
 		 */
 		lastconn = ((const struct ip *)&p[SLX_CHDR])->ip_p;
+		ND_PRINT((ndo, "utcp %d: ", lastconn));
+		if (dir == -1) {
+			/* Direction is bogus, don't use it */
+			return;
+		}
 		hlen = IP_HL(ip);
 		hlen += TH_OFF((const struct tcphdr *)&((const int *)ip)[hlen]);
 		lastlen[dir][lastconn] = length - (hlen << 2);
-		ND_PRINT((ndo, "utcp %d: ", lastconn));
 		break;
 
 	default:
+		if (dir == -1) {
+			/* Direction is bogus, don't use it */
+			return;
+		}
 		if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 			compressed_sl_print(ndo, &p[SLX_CHDR], ip,
 			    length, dir);