This is an optional patch which removes duplicated code
from tcp6_cksum: comparison shows that the code of in_cksum
re-appears in that function.
In addition, it fixes a typo in printing invalid checksums:
* previously: "cksum xDEAD (incorrect (-> xBEEF)"
* now: "cksum xDEAD (incorrect -> xBEEF)"
Regards
Gerrit Renker
---
print-tcp.c | 20 +++-----------------
1 file changed, 3 insertions(+), 17 deletions(-)
diff --git a/print-tcp.c b/print-tcp.c
index 11bd6b7..a988c52 100644
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -147,8 +147,7 @@ static int tcp6_cksum(const struct ip6_h
u_int len)
{
size_t i;
- register const u_int16_t *sp;
- u_int32_t sum;
+ u_int32_t sum = 0;
union {
struct {
struct in6_addr ph_src;
@@ -167,23 +166,10 @@ static int tcp6_cksum(const struct ip6_h
phu.ph.ph_len = htonl(len);
phu.ph.ph_nxt = IPPROTO_TCP;
- sum = 0;
for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
sum += phu.pa[i];
- sp = (const u_int16_t *)tp;
-
- for (i = 0; i < (len & ~1); i += 2)
- sum += *sp++;
-
- if (len & 1)
- sum += htons((*(const u_int8_t *)sp) << 8);
-
- while (sum > 0xffff)
- sum = (sum & 0xffff) + (sum >> 16);
- sum = ~sum & 0xffff;
-
- return (sum);
+ return in_cksum((u_short *)tp, len, sum);
}
#endif
@@ -428,7 +414,7 @@ #endif
(void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum));
if (sum != 0) {
tcp_sum = EXTRACT_16BITS(&tp->th_sum);
- (void)printf(" (incorrect (-> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
+ (void)printf(" (incorrect -> 0x%04x),",in_cksum_shouldbe(tcp_sum, sum));
} else
(void)printf(" (correct),");
}
-
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