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-rw-r--r--util.c40
1 files changed, 26 insertions, 14 deletions
diff --git a/util.c b/util.c
index 1372eec..4d4661a 100644
--- a/util.c
+++ b/util.c
@@ -77,6 +77,29 @@ logfn(debug, LOG_DEBUG)
#endif
/**
+ * sum_16b() - Calculate sum of 16-bit words
+ * @buf: Input buffer
+ * @len: Buffer length
+ *
+ * Return: 32-bit sum of 16-bit words
+*/
+uint32_t sum_16b(void *buf, size_t len)
+{
+ uint32_t sum = 0;
+ uint16_t *p = buf;
+ size_t len1 = len / 2;
+ size_t off;
+
+ for (off = 0; off < len1; off++, p++)
+ sum += *p;
+
+ if (len % 2)
+ sum += *p & 0xff;
+
+ return sum;
+}
+
+/**
* csum_fold() - Fold long sum for IP and TCP checksum
* @sum: Original long sum
*
@@ -91,7 +114,7 @@ uint16_t csum_fold(uint32_t sum)
}
/**
- * csum_ipv4() - Calculate IPv4 checksum
+ * csum_ip4() - Calculate IPv4 checksum
* @buf: Packet buffer, L3 headers
* @len: Total L3 packet length
*
@@ -99,22 +122,11 @@ uint16_t csum_fold(uint32_t sum)
*/
uint16_t csum_ip4(void *buf, size_t len)
{
- uint32_t sum = 0;
- uint16_t *p = buf;
- size_t len1 = len / 2;
- size_t off;
-
- for (off = 0; off < len1; off++, p++)
- sum += *p;
-
- if (len % 2)
- sum += *p & 0xff;
-
- return ~csum_fold(sum);
+ return ~csum_fold(sum_16b(buf, len));
}
/**
- * csum_ipv4() - Calculate TCP checksum for IPv4 and set in place
+ * csum_tcp4() - Calculate TCP checksum for IPv4 and set in place
* @iph: Packet buffer, IP header
*/
void csum_tcp4(struct iphdr *iph)