Validate argument to port option - bug 18695

6 files changed, 35 insertions, 14 deletions

diff --git a/RELNOTES b/RELNOTES
index 40e263d5..a467eb5c 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -52,6 +52,10 @@ may not work on other platforms. Please report any problems and
 suggested fixes to <dhcp-users@isc.org>.
 
 
+			Changes since 4.0.1 (bug fixes)
+
+- Validate the argument to the -p option.
+
 			Changes since 4.0.1rc1
 
 - None.
diff --git a/client/dhclient.c b/client/dhclient.c
index 944b2860..54626aae 100644
--- a/client/dhclient.c
+++ b/client/dhclient.c
@@ -164,7 +164,7 @@ main(int argc, char **argv) {
 		} else if (!strcmp (argv [i], "-p")) {
 			if (++i == argc)
 				usage ();
-			local_port = htons (atoi (argv [i]));
+			local_port = validate_port (argv [i]);
 			log_debug ("binding to user-specified port %d",
 			       ntohs (local_port));
 		} else if (!strcmp (argv [i], "-d")) {
diff --git a/common/inet.c b/common/inet.c
index 7bee0888..1d50d40e 100644
--- a/common/inet.c
+++ b/common/inet.c
@@ -1,10 +1,10 @@
 /* inet.c
 
-   Subroutines to manipulate internet addresses in a safely portable
+   Subroutines to manipulate internet addresses and ports in a safely portable
    way... */
 
 /*
- * Copyright (c) 2004,2005,2007 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 2004,2005,2007,2008 by Internet Systems Consortium, Inc. ("ISC")
  * Copyright (c) 1995-2003 by Internet Software Consortium
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -604,3 +604,26 @@ piaddrcidr(const struct iaddr *addr, unsigned int bits) {
 	return ret;
 }
 
+/* Validate that the string represents a valid port number and
+ * return it in network byte order
+ */
+
+u_int16_t
+validate_port(char *port) {
+	int local_port = 0;
+	int lower = 1;
+	int upper = 65535;
+	char *endptr;
+
+	errno = 0;
+	local_port = strtol(port, &endptr, 10);
+	
+	if ((*endptr != '\0') || (errno == ERANGE) || (errno == EINVAL))
+		log_fatal ("Invalid port number specification: %s", port);
+
+	if (local_port < lower || local_port > upper)
+		log_fatal("Port number specified is out of range (%d-%d).",
+			  lower, upper);
+
+	return htons(local_port);
+}
diff --git a/includes/dhcpd.h b/includes/dhcpd.h
index 7652e7ba..ab23ed39 100644
--- a/includes/dhcpd.h
+++ b/includes/dhcpd.h
@@ -40,6 +40,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <arpa/inet.h>
+#include <errno.h>
 
 #include <netdb.h>
 #else
@@ -2378,6 +2379,7 @@ isc_result_t free_iaddrcidrnetlist(struct iaddrcidrnetlist **result);
 const char *piaddr PROTO ((struct iaddr));
 char *piaddrmask(struct iaddr *, struct iaddr *);
 char *piaddrcidr(const struct iaddr *, unsigned int);
+u_int16_t validate_port(char *);
 
 /* dhclient.c */
 extern int nowait;
diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
index 60b5ce81..fd132a93 100644
--- a/relay/dhcrelay.c
+++ b/relay/dhcrelay.c
@@ -144,7 +144,7 @@ main(int argc, char **argv) {
 		if (!strcmp (argv [i], "-p")) {
 			if (++i == argc)
 				usage ();
-			local_port = htons (atoi (argv [i]));
+			local_port = validate_port (argv [i]);
 			log_debug ("binding to user-specified port %d",
 			       ntohs (local_port));
 		} else if (!strcmp (argv [i], "-d")) {
diff --git a/server/dhcpd.c b/server/dhcpd.c
index 7cf05bd7..e800fa6b 100644
--- a/server/dhcpd.c
+++ b/server/dhcpd.c
@@ -259,15 +259,7 @@ main(int argc, char **argv) {
 		if (!strcmp (argv [i], "-p")) {
 			if (++i == argc)
 				usage ();
-			for (s = argv [i]; *s; s++)
-				if (!isdigit ((unsigned char)*s))
-					log_fatal ("%s: not a valid UDP port",
-					       argv [i]);
-			status = atoi (argv [i]);
-			if (status < 1 || status > 65535)
-				log_fatal ("%s: not a valid UDP port",
-				       argv [i]);
-			local_port = htons (status);
+			local_port = validate_port (argv [i]);
 			log_debug ("binding to user-specified port %d",
 			       ntohs (local_port));
 		} else if (!strcmp (argv [i], "-f")) {
@@ -440,7 +432,7 @@ main(int argc, char **argv) {
 	if (!local_port)
 	{
 		if ((s = getenv ("DHCPD_PORT"))) {
-			local_port = htons (atoi (s));
+			local_port = validate_port (s);
 			log_debug ("binding to environment-specified port %d",
 				   ntohs (local_port));
 		} else {