[NET]: UML checksum annotations and cleanups.

* sanitize prototypes, annotate
* kill csum_partial_copy_fromuser
* kill shift-by-16 in checksum calculations
* ntohs->shift in checksum calculations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/um/include/sysdep-i386/checksum.h

@@ -20,8 +20,7 @@
  *
  * it's best to have buff aligned on a 32-bit boundary
  */
-unsigned int csum_partial(const unsigned char * buff, int len, 
-			  unsigned int sum);
+__wsum csum_partial(const void *buff, int len, __wsum sum);
 
 /*
  *	Note: when you get a NULL pointer exception here this means someone
@@ -32,8 +31,8 @@ unsigned int csum_partial(const unsigned char * buff, int len,
  */
 
 static __inline__
-unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst,
-				       int len, int sum)
+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
+				       int len, __wsum sum)
 {
 	memcpy(dst, src, len);
 	return csum_partial(dst, len, sum);
@@ -48,27 +47,17 @@ unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *
  */
 
 static __inline__
-unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
-					 unsigned char *dst,
-					 int len, int sum, int *err_ptr)
+__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+					 int len, __wsum sum, int *err_ptr)
 {
-	if(copy_from_user(dst, src, len)){
+	if (copy_from_user(dst, src, len)) {
 		*err_ptr = -EFAULT;
-		return(-1);
+		return (__force __wsum)-1;
 	}
 
 	return csum_partial(dst, len, sum);
 }
 
-/*
- * These are the old (and unsafe) way of doing checksums, a warning message 
- * will be printed if they are used and an exception occurs.
- *
- * these functions should go away after some time.
- */
-
-#define csum_partial_copy_fromuser csum_partial_copy_from_user
-
 /*
  *	This is a version of ip_compute_csum() optimized for IP headers,
  *	which always checksum on 4 octet boundaries.
@@ -76,8 +65,7 @@ unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
  *	By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
  *	Arnt Gulbrandsen.
  */
-static inline unsigned short ip_fast_csum(unsigned char * iph,
-					  unsigned int ihl)
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 {
 	unsigned int sum;
 
@@ -105,29 +93,29 @@ static inline unsigned short ip_fast_csum(unsigned char * iph,
 	: "=r" (sum), "=r" (iph), "=r" (ihl)
 	: "1" (iph), "2" (ihl)
 	: "memory");
-	return sum;
+	return (__force __sum16)sum;
 }
 
 /*
  *	Fold a partial checksum
  */
 
-static inline unsigned int csum_fold(unsigned int sum)
+static inline __sum16 csum_fold(__wsum sum)
 {
 	__asm__(
 		"addl %1, %0		;\n"
 		"adcl $0xffff, %0	;\n"
 		: "=r" (sum)
-		: "r" (sum << 16), "0" (sum & 0xffff0000)
+		: "r" ((__force u32)sum << 16),
+		  "0" ((__force u32)sum & 0xffff0000)
 	);
-	return (~sum) >> 16;
+	return (__force __sum16)(~(__force u32)sum >> 16);
 }
 
-static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
-						   unsigned long daddr,
+static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 						   unsigned short len,
 						   unsigned short proto,
-						   unsigned int sum)
+						   __wsum sum)
 {
     __asm__(
 	"addl %1, %0	;\n"
@@ -135,7 +123,7 @@ static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
 	"adcl %3, %0	;\n"
 	"adcl $0, %0	;\n"
 	: "=r" (sum)
-	: "g" (daddr), "g"(saddr), "g"((ntohs(len)<<16)+proto*256), "0"(sum));
+	: "g" (daddr), "g"(saddr), "g"((len + proto) << 8), "0"(sum));
     return sum;
 }
 
@@ -143,11 +131,10 @@ static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
  * computes the checksum of the TCP/UDP pseudo-header
  * returns a 16-bit checksum, already complemented
  */
-static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
-						   unsigned long daddr,
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 						   unsigned short len,
 						   unsigned short proto,
-						   unsigned int sum)
+						   __wsum sum)
 {
 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 }
@@ -157,17 +144,16 @@ static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
  * in icmp.c
  */
 
-static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
+static inline __sum16 ip_compute_csum(const void *buff, int len)
 {
     return csum_fold (csum_partial(buff, len, 0));
 }
 
 #define _HAVE_ARCH_IPV6_CSUM
-static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
-						     struct in6_addr *daddr,
-						     __u32 len,
-						     unsigned short proto,
-						     unsigned int sum)
+static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+					  const struct in6_addr *daddr,
+					  __u32 len, unsigned short proto,
+					  __wsum sum)
 {
 	__asm__(
 		"addl 0(%1), %0		;\n"
@@ -192,14 +178,14 @@ static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
  *	Copy and checksum to user
  */
 #define HAVE_CSUM_COPY_USER
-static __inline__ unsigned int csum_and_copy_to_user(const unsigned char *src,
-						     unsigned char __user *dst,
-						     int len, int sum, int *err_ptr)
+static __inline__ __wsum csum_and_copy_to_user(const void *src,
+						     void __user *dst,
+						     int len, __wsum sum, int *err_ptr)
 {
-	if (access_ok(VERIFY_WRITE, dst, len)){
-		if(copy_to_user(dst, src, len)){
+	if (access_ok(VERIFY_WRITE, dst, len)) {
+		if (copy_to_user(dst, src, len)) {
 			*err_ptr = -EFAULT;
-			return(-1);
+			return (__force __wsum)-1;
 		}
 
 		return csum_partial(src, len, sum);
@@ -208,7 +194,7 @@ static __inline__ unsigned int csum_and_copy_to_user(const unsigned char *src,
 	if (len)
 		*err_ptr = -EFAULT;
 
-	return -1; /* invalid checksum */
+	return (__force __wsum)-1; /* invalid checksum */
 }
 
 #endif

arch/um/include/sysdep-x86_64/checksum.h

@@ -9,8 +9,7 @@
 #include "linux/in6.h"
 #include "asm/uaccess.h"
 
-extern unsigned csum_partial(const unsigned char *buff, unsigned len,
-                             unsigned sum);
+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
 
 /*
  *	Note: when you get a NULL pointer exception here this means someone
@@ -21,21 +20,21 @@ extern unsigned csum_partial(const unsigned char *buff, unsigned len,
  */
 
 static __inline__
-unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst,
-				       int len, int sum)
+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
+				       int len, __wsum sum)
 {
 	memcpy(dst, src, len);
 	return(csum_partial(dst, len, sum));
 }
 
 static __inline__
-unsigned int csum_partial_copy_from_user(const unsigned char *src,
-                                         unsigned char *dst, int len, int sum,
+__wsum csum_partial_copy_from_user(const void __user *src,
+                                         void *dst, int len, __wsum sum,
                                          int *err_ptr)
 {
-        if(copy_from_user(dst, src, len)){
+        if (copy_from_user(dst, src, len)) {
                 *err_ptr = -EFAULT;
-                return(-1);
+                return (__force __wsum)-1;
         }
         return csum_partial(dst, len, sum);
 }
@@ -48,15 +47,16 @@ unsigned int csum_partial_copy_from_user(const unsigned char *src,
  * the last step before putting a checksum into a packet.
  * Make sure not to mix with 64bit checksums.
  */
-static inline unsigned int csum_fold(unsigned int sum)
+static inline __sum16 csum_fold(__wsum sum)
 {
 	__asm__(
 		"  addl %1,%0\n"
 		"  adcl $0xffff,%0"
 		: "=r" (sum)
-		: "r" (sum << 16), "0" (sum & 0xffff0000)
+		: "r" ((__force u32)sum << 16),
+		  "0" ((__force u32)sum & 0xffff0000)
 	);
-	return (~sum) >> 16;
+	return (__force __sum16)(~(__force u32)sum >> 16);
 }
 
 /**
@@ -70,28 +70,27 @@ static inline unsigned int csum_fold(unsigned int sum)
  * Returns the pseudo header checksum the input data. Result is
  * 32bit unfolded.
  */
-static inline unsigned long
-csum_tcpudp_nofold(unsigned saddr, unsigned daddr, unsigned short len,
-		   unsigned short proto, unsigned int sum)
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+		   unsigned short proto, __wsum sum)
 {
 	asm("  addl %1, %0\n"
 	    "  adcl %2, %0\n"
 	    "  adcl %3, %0\n"
 	    "  adcl $0, %0\n"
 		: "=r" (sum)
-	    : "g" (daddr), "g" (saddr), "g" ((ntohs(len)<<16)+proto*256), "0" (sum));
-    return sum;
+	    : "g" (daddr), "g" (saddr), "g" ((len + proto) << 8), "0" (sum));
+	return sum;
 }
 
 /*
  * computes the checksum of the TCP/UDP pseudo-header
  * returns a 16-bit checksum, already complemented
  */
-static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
-						   unsigned long daddr,
-						   unsigned short len,
-						   unsigned short proto,
-						   unsigned int sum)
+static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
+					   unsigned short len,
+					   unsigned short proto,
+					   __wsum sum)
 {
 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 }
@@ -101,7 +100,7 @@ static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
  * iph: ipv4 header
  * ihl: length of header / 4
  */
-static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 {
 	unsigned int sum;
 
@@ -128,7 +127,7 @@ static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
 	: "=r" (sum), "=r" (iph), "=r" (ihl)
 	: "1" (iph), "2" (ihl)
 	: "memory");
-	return(sum);
+	return (__force __sum16)sum;
 }
 
 static inline unsigned add32_with_carry(unsigned a, unsigned b)
@@ -140,6 +139,6 @@ static inline unsigned add32_with_carry(unsigned a, unsigned b)
         return a;
 }
 
-extern unsigned short ip_compute_csum(unsigned char * buff, int len);
+extern __sum16 ip_compute_csum(const void *buff, int len);
 
 #endif