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tcp: Unify initial sequence number calculation for IPv4 and IPv6

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tcp_seq_init() has separate paths for IPv4 and IPv6 addresses, which means
we will calculate different sequence numbers for IPv4 and equivalent
IPv4-mapped IPv6 addresses.

Change it to treat these the same by always converting the input address
into an inany_addr representation and use that to calculate the sequence
number.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2022-11-17 16:58:59 +11:00 committed by Stefano Brivio
parent 7114fc92eb
commit a93bfada5b
2 changed files with 19 additions and 28 deletions
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1
siphash.c
View file

@ -123,6 +123,7 @@ uint64_t siphash_8b(const uint8_t *in, const uint64_t *k)
*
* Return: 32 bits obtained by XORing the two halves of the 64-bit hash output
*/
/* cppcheck-suppress unusedFunction */
uint32_t siphash_12b(const uint8_t *in, const uint64_t *k)
{
uint32_t *in32 = (uint32_t *)in;

46
tcp.c
View file

@ -1942,37 +1942,27 @@ static uint32_t tcp_seq_init(const struct ctx *c, int af, const void *addr,
in_port_t dstport, in_port_t srcport,
const struct timespec *now)
{
union inany_addr aany;
struct {
union inany_addr src;
in_port_t srcport;
union inany_addr dst;
in_port_t dstport;
} __attribute__((__packed__)) in = {
.srcport = srcport,
.dstport = dstport,
};
uint32_t ns, seq = 0;
if (af == AF_INET) {
struct {
struct in_addr src;
in_port_t srcport;
struct in_addr dst;
in_port_t dstport;
} __attribute__((__packed__)) in = {
.src = *(struct in_addr *)addr,
.srcport = srcport,
.dst = c->ip4.addr,
.dstport = dstport,
};
inany_from_af(&aany, af, addr);
in.src = aany;
if (af == AF_INET)
inany_from_af(&aany, AF_INET, &c->ip4.addr);
else
inany_from_af(&aany, AF_INET6, &c->ip6.addr);
in.dst = aany;
seq = siphash_12b((uint8_t *)&in, c->tcp.hash_secret);
} else if (af == AF_INET6) {
struct {
struct in6_addr src;
in_port_t srcport;
struct in6_addr dst;
in_port_t dstport;
} __attribute__((__packed__)) in = {
.src = *(struct in6_addr *)addr,
.srcport = srcport,
.dst = c->ip6.addr,
.dstport = dstport,
};
seq = siphash_36b((uint8_t *)&in, c->tcp.hash_secret);
}
seq = siphash_36b((uint8_t *)&in, c->tcp.hash_secret);
ns = now->tv_sec * 1E9;
ns += now->tv_nsec >> 5; /* 32ns ticks, overflows 32 bits every 137s */