X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/99c91c3aec40b691641374f58e798bd8d6b657bd..d7b497cac78b6e22a66a6bae9bdec60a8044f67a:/print-sl.c

diff --git a/print-sl.c b/print-sl.c
index b69a07d5..419864ef 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);
@@ -123,15 +131,28 @@ 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;
 
 		for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
-			ND_PRINT((ndo, "%02x.", p[i]));
-		ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1]));
+			ND_PRINT((ndo, "%02x.", EXTRACT_U_1(p + i)));
+		ND_PRINT((ndo, "%02x: ", EXTRACT_U_1(p + SLX_CHDR + CHDR_LEN - 1)));
 		return;
 	}
 	switch (p[SLX_CHDR] & 0xf0) {
@@ -147,19 +168,27 @@ 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);
 			ND_PRINT((ndo, ": "));
 		} else
-			ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR]));
+			ND_PRINT((ndo, "slip-%d!: ", EXTRACT_U_1(p + SLX_CHDR)));
 	}
 }
 
@@ -170,7 +199,7 @@ print_sl_change(netdissect_options *ndo,
 	register u_int i;
 
 	if ((i = *cp++) == 0) {
-		i = EXTRACT_16BITS(cp);
+		i = EXTRACT_BE_U_2(cp);
 		cp += 2;
 	}
 	ND_PRINT((ndo, " %s%d", str, i));
@@ -184,7 +213,7 @@ print_sl_winchange(netdissect_options *ndo,
 	register short i;
 
 	if ((i = *cp++) == 0) {
-		i = EXTRACT_16BITS(cp);
+		i = EXTRACT_BE_U_2(cp);
 		cp += 2;
 	}
 	if (i >= 0)
@@ -202,9 +231,11 @@ compressed_sl_print(netdissect_options *ndo,
 	register const u_char *cp = chdr;
 	register u_int flags, hlen;
 
-	flags = *cp++;
+	flags = EXTRACT_U_1(cp);
+	cp++;
 	if (flags & NEW_C) {
-		lastconn = *cp++;
+		lastconn = EXTRACT_U_1(cp);
+		cp++;
 		ND_PRINT((ndo, "ctcp %d", lastconn));
 	} else
 		ND_PRINT((ndo, "ctcp *"));