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(a)gibson.dropbear.id.au>
---
siphash.c | 1 +
tcp.c | 46 ++++++++++++++++++----------------------------
2 files changed, 19 insertions(+), 28 deletions(-)
diff --git a/siphash.c b/siphash.c
index 516a508..811918b 100644
--- a/siphash.c
+++ b/siphash.c
@@ -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;
diff --git a/tcp.c b/tcp.c
index 8ebd90a..ac64b81 100644
--- a/tcp.c
+++ b/tcp.c
@@ -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,
- };
-
- 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,
- };
+ 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_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 */
--
2.38.1