net: Make setsockopt() optlen be unsigned.

This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller <davem@davemloft.net>

net/atm/common.c

@@ -679,7 +679,7 @@ static int check_qos(const struct atm_qos *qos)
 }
 
 int vcc_setsockopt(struct socket *sock, int level, int optname,
-		   char __user *optval, int optlen)
+		   char __user *optval, unsigned int optlen)
 {
 	struct atm_vcc *vcc;
 	unsigned long value;

net/atm/common.h

@@ -21,7 +21,7 @@ unsigned int vcc_poll(struct file *file, struct socket *sock, poll_table *wait);
 int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 int vcc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 int vcc_setsockopt(struct socket *sock, int level, int optname,
-		   char __user *optval, int optlen);
+		   char __user *optval, unsigned int optlen);
 int vcc_getsockopt(struct socket *sock, int level, int optname,
 		   char __user *optval, int __user *optlen);
 

net/atm/pvc.c

@@ -59,7 +59,7 @@ static int pvc_connect(struct socket *sock,struct sockaddr *sockaddr,
 }
 
 static int pvc_setsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int optlen)
+			  char __user *optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
 	int error;

net/atm/svc.c

@@ -446,7 +446,7 @@ int svc_change_qos(struct atm_vcc *vcc,struct atm_qos *qos)
 
 
 static int svc_setsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int optlen)
+			  char __user *optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
 	struct atm_vcc *vcc = ATM_SD(sock);