X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fcsum.c;h=a9334fec8528ead7b5156352537a928d9b55ab77;hb=6d308b28c023e864925b1a6775b3b91d215e89bf;hp=6f044473e2f87607ccdd071e87f28540b25a048d;hpb=34e63086edddcae06d7c1a4fa84fec0861e50758;p=sliver-openvswitch.git

diff --git a/lib/csum.c b/lib/csum.c
index 6f044473e..a9334fec8 100644
--- a/lib/csum.c
+++ b/lib/csum.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,9 @@
 
 #include <config.h>
 #include "csum.h"
+#include "unaligned.h"
+
+#ifndef __CHECKER__
 
 /* Returns the IP checksum of the 'n' bytes in 'data'.
  *
@@ -23,7 +26,7 @@
  * consists of a packet in network byte order, then the return value is a value
  * in network byte order, and if 'data' consists of a data structure in host
  * byte order, then the return value is in host byte order. */
-uint16_t
+ovs_be16
 csum(const void *data, size_t n)
 {
     return csum_finish(csum_continue(0, data, n));
@@ -33,7 +36,7 @@ csum(const void *data, size_t n)
  * the updated checksum.  (To start a new checksum, pass 0 for 'partial'.  To
  * obtain the finished checksum, pass the return value to csum_finish().) */
 uint32_t
-csum_add16(uint32_t partial, uint16_t new)
+csum_add16(uint32_t partial, ovs_be16 new)
 {
     return partial + new;
 }
@@ -42,7 +45,7 @@ csum_add16(uint32_t partial, uint16_t new)
  * the updated checksum.  (To start a new checksum, pass 0 for 'partial'.  To
  * obtain the finished checksum, pass the return value to csum_finish().) */
 uint32_t
-csum_add32(uint32_t partial, uint32_t new)
+csum_add32(uint32_t partial, ovs_be32 new)
 {
     return partial + (new >> 16) + (new & 0xffff);
 }
@@ -55,10 +58,10 @@ csum_add32(uint32_t partial, uint32_t new)
 uint32_t
 csum_continue(uint32_t partial, const void *data_, size_t n)
 {
-    const uint16_t *data = data_;
+    const ovs_be16 *data = data_;
 
-    for (; n > 1; n -= 2) {
-        partial = csum_add16(partial, *data++);
+    for (; n > 1; n -= 2, data++) {
+        partial = csum_add16(partial, get_unaligned_be16(data));
     }
     if (n) {
         partial += *(uint8_t *) data;
@@ -73,17 +76,20 @@ csum_continue(uint32_t partial, const void *data_, size_t n)
  * if the data consist of a packet in network byte order, then the return value
  * is a value in network byte order, and if the data are a data structure in
  * host byte order, then the return value is in host byte order. */
-uint16_t
+ovs_be16
 csum_finish(uint32_t partial)
 {
-    return ~((partial & 0xffff) + (partial >> 16));
+    while (partial >> 16) {
+        partial = (partial & 0xffff) + (partial >> 16);
+    }
+    return ~partial;
 }
 
 /* Returns the new checksum for a packet in which the checksum field previously
  * contained 'old_csum' and in which a field that contained 'old_u16' was
  * changed to contain 'new_u16'. */
-uint16_t
-recalc_csum16(uint16_t old_csum, uint16_t old_u16, uint16_t new_u16)
+ovs_be16
+recalc_csum16(ovs_be16 old_csum, ovs_be16 old_u16, ovs_be16 new_u16)
 {
     /* Ones-complement arithmetic is endian-independent, so this code does not
      * use htons() or ntohs().
@@ -93,16 +99,36 @@ recalc_csum16(uint16_t old_csum, uint16_t old_u16, uint16_t new_u16)
     uint16_t m_complement = ~old_u16;
     uint16_t m_prime = new_u16;
     uint32_t sum = hc_complement + m_complement + m_prime;
-    uint16_t hc_prime_complement = sum + (sum >> 16);
-    return ~hc_prime_complement;
+    return csum_finish(sum);
 }
 
 /* Returns the new checksum for a packet in which the checksum field previously
  * contained 'old_csum' and in which a field that contained 'old_u32' was
  * changed to contain 'new_u32'. */
-uint16_t
-recalc_csum32(uint16_t old_csum, uint32_t old_u32, uint32_t new_u32)
+ovs_be16
+recalc_csum32(ovs_be16 old_csum, ovs_be32 old_u32, ovs_be32 new_u32)
 {
     return recalc_csum16(recalc_csum16(old_csum, old_u32, new_u32),
                          old_u32 >> 16, new_u32 >> 16);
 }
+
+/* Returns the new checksum for a packet in which the checksum field previously
+ * contained 'old_csum' and in which a field that contained 'old_u32[4]' was
+ * changed to contain 'new_u32[4]'. */
+ovs_be16
+recalc_csum128(ovs_be16 old_csum, ovs_16aligned_be32 old_u32[4],
+               const ovs_be32 new_u32[4])
+{
+    ovs_be16 new_csum = old_csum;
+    int i;
+
+    for (i = 0; i < 4; ++i) {
+        new_csum = recalc_csum32(new_csum,
+                                 get_16aligned_be32(&old_u32[i]), new_u32[i]);
+    }
+    return new_csum;
+}
+#else  /* __CHECKER__ */
+/* Making sparse happy with these functions also makes them unreadable, so
+ * don't bother to show it their implementations. */
+#endif