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checksum: use csum_ip4_header() in udp.c and tcp.c

We can find the same function to compute the IPv4 header
checksum in tcp.c, udp.c and tap.c

Use the function defined for tap.c, csum_ip4_header(), but
with the code used in tcp.c and udp.c as it doesn't need a fully
initialiazed IPv4 header, only protocol, tot_len, saddr and daddr.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-ID: <20240303135114.1023026-7-lvivier@redhat.com>
[dwg: Fix weird cppcheck regression; it appears to be a problem
 in pre-existing code, but somehow this patch is exposing it]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Laurent Vivier 2024-03-06 16:58:35 +11:00 committed by Stefano Brivio
parent e82b4fe5fc
commit feb4900c25
5 changed files with 27 additions and 46 deletions

24
tcp.c
View file

@ -935,23 +935,6 @@ static void tcp_sock_set_bufsize(const struct ctx *c, int s)
trace("TCP: failed to set SO_SNDBUF to %i", v);
}
/**
* tcp_update_check_ip4() - Update IPv4 with variable parts from stored one
* @buf: L2 packet buffer with final IPv4 header
*/
static void tcp_update_check_ip4(struct tcp4_l2_buf_t *buf)
{
uint32_t sum = L2_BUF_IP4_PSUM(IPPROTO_TCP);
sum += buf->iph.tot_len;
sum += (buf->iph.saddr >> 16) & 0xffff;
sum += buf->iph.saddr & 0xffff;
sum += (buf->iph.daddr >> 16) & 0xffff;
sum += buf->iph.daddr & 0xffff;
buf->iph.check = (uint16_t)~csum_fold(sum);
}
/**
* tcp_update_check_tcp4() - Update TCP checksum from stored one
* @buf: L2 packet buffer with final IPv4 header
@ -1394,10 +1377,9 @@ do { \
b->iph.saddr = a4->s_addr;
b->iph.daddr = c->ip4.addr_seen.s_addr;
if (check)
b->iph.check = *check;
else
tcp_update_check_ip4(b);
b->iph.check = check ? *check :
csum_ip4_header(b->iph.tot_len, IPPROTO_TCP,
*a4, c->ip4.addr_seen);
SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq);