X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/99c91c3aec40b691641374f58e798bd8d6b657bd..1a04b92e365f5ed01ca38619b41bcc4fc9cbd63c:/print-telnet.c

diff --git a/print-telnet.c b/print-telnet.c
index e01e91b8..41e24462 100644
--- a/print-telnet.c
+++ b/print-telnet.c
@@ -45,6 +45,8 @@
  *      are preserved in all copies.
  */
 
+/* \summary: Telnet option printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
@@ -54,6 +56,9 @@
 #include <stdio.h>
 
 #include "netdissect.h"
+#include "extract.h"
+
+static const char tstr[] = " [|telnet]";
 
 #define TELCMDS
 #define TELOPTS
@@ -87,7 +92,7 @@
 #define SYNCH	242		/* for telfunc calls */
 
 #ifdef TELCMDS
-const char *telcmds[] = {
+static const char *telcmds[] = {
 	"EOF", "SUSP", "ABORT", "EOR",
 	"SE", "NOP", "DMARK", "BRK", "IP", "AO", "AYT", "EC",
 	"EL", "GA", "SB", "WILL", "WONT", "DO", "DONT", "IAC", 0,
@@ -148,7 +153,7 @@ extern char *telcmds[];
 
 #define	NTELOPTS	(1+TELOPT_NEW_ENVIRON)
 #ifdef TELOPTS
-const char *telopts[NTELOPTS+1] = {
+static const char *telopts[NTELOPTS+1] = {
 	"BINARY", "ECHO", "RCP", "SUPPRESS GO AHEAD", "NAME",
 	"STATUS", "TIMING MARK", "RCTE", "NAOL", "NAOP",
 	"NAOCRD", "NAOHTS", "NAOHTD", "NAOFFD", "NAOVTS",
@@ -433,11 +438,13 @@ telnet_parse(netdissect_options *ndo, const u_char *sp, u_int length, int print)
 		/* IAC SB .... IAC SE */
 		p = sp;
 		while (length > (u_int)(p + 1 - sp)) {
-			if (p[0] == IAC && p[1] == SE)
+			ND_TCHECK_2(p);
+			if (EXTRACT_U_1(p) == IAC && EXTRACT_U_1(p + 1) == SE)
 				break;
 			p++;
 		}
-		if (*p != IAC)
+		ND_TCHECK_1(p);
+		if (EXTRACT_U_1(p) != IAC)
 			goto pktend;
 
 		switch (x) {
@@ -493,7 +500,7 @@ done:
 	return sp - osp;
 
 trunc:
-	ND_PRINT((ndo, "[|telnet]"));
+	ND_PRINT((ndo, "%s", tstr));
 pktend:
 	return -1;
 #undef FETCH
@@ -508,7 +515,8 @@ telnet_print(netdissect_options *ndo, const u_char *sp, u_int length)
 
 	osp = sp;
 
-	while (length > 0 && *sp == IAC) {
+	ND_TCHECK_1(sp);
+	while (length > 0 && EXTRACT_U_1(sp) == IAC) {
 		/*
 		 * Parse the Telnet command without printing it,
 		 * to determine its length.
@@ -536,6 +544,7 @@ telnet_print(netdissect_options *ndo, const u_char *sp, u_int length)
 
 		sp += l;
 		length -= l;
+		ND_TCHECK_1(sp);
 	}
 	if (!first) {
 		if (ndo->ndo_Xflag && 2 < ndo->ndo_vflag)
@@ -543,4 +552,7 @@ telnet_print(netdissect_options *ndo, const u_char *sp, u_int length)
 		else
 			ND_PRINT((ndo, "]"));
 	}
+	return;
+trunc:
+	ND_PRINT((ndo, "%s", tstr));
 }