IPv4 are now hashed to match equivalent IPv4-mapped IPv6 addresses. This
means we can avoid having IPv4 specific paths in the lower level hash and
match functions, instead just dealing with the equivalent IPv4-mapped IPv6
addresses.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
tcp.c | 44 +++++++++++++++++---------------------------
1 file changed, 17 insertions(+), 27 deletions(-)
diff --git a/tcp.c b/tcp.c
index dfa73a3..3816a1c 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1275,23 +1275,16 @@ static int tcp_opt_get(const char *opts, size_t len, uint8_t
type_find,
/**
* tcp_hash_match() - Check if a connection entry matches address and ports
* @conn: Connection entry to match against
- * @af: Address family, AF_INET or AF_INET6
- * @addr: Remote address, pointer to in_addr or in6_addr
+ * @addr: Remote address, may be IPv4-mapped
* @tap_port: tap-facing port
* @sock_port: Socket-facing port
*
* Return: 1 on match, 0 otherwise
*/
-static int tcp_hash_match(const struct tcp_conn *conn, int af, const void *addr,
+static int tcp_hash_match(const struct tcp_conn *conn,
+ const struct in6_addr *addr,
in_port_t tap_port, in_port_t sock_port)
{
- struct in6_addr v4mapped;
-
- if (af == AF_INET) {
- encode_ip4mapped_ip6(&v4mapped, addr);
- addr = &v4mapped;
- }
-
if (IN6_ARE_ADDR_EQUAL(&conn->a.a6, addr) &&
conn->tap_port == tap_port && conn->sock_port == sock_port)
return 1;
@@ -1302,8 +1295,7 @@ static int tcp_hash_match(const struct tcp_conn *conn, int af, const
void *addr,
/**
* tcp_hash() - Calculate hash value for connection given address and ports
* @c: Execution context
- * @af: Address family, AF_INET or AF_INET6
- * @addr: Remote address, pointer to in_addr or in6_addr
+ * @addr: Remote address, may be IPv4-mapped
* @tap_port: tap-facing port
* @sock_port: Socket-facing port
*
@@ -1312,7 +1304,7 @@ static int tcp_hash_match(const struct tcp_conn *conn, int af, const
void *addr,
#if TCP_HASH_NOINLINE
__attribute__((__noinline__)) /* See comment in Makefile */
#endif
-static unsigned int tcp_hash(const struct ctx *c, int af, const void *addr,
+static unsigned int tcp_hash(const struct ctx *c, const struct in6_addr *addr,
in_port_t tap_port, in_port_t sock_port)
{
struct {
@@ -1320,20 +1312,10 @@ static unsigned int tcp_hash(const struct ctx *c, int af, const
void *addr,
in_port_t tap_port;
in_port_t sock_port;
} __attribute__((__packed__)) in = {
- .tap_port = tap_port,
- .sock_port = sock_port,
+ *addr, tap_port, sock_port,
};
uint64_t b = 0;
- if (af == AF_INET) {
- struct in6_addr v4mapped;
-
- encode_ip4mapped_ip6(&v4mapped, addr);
- in.addr = v4mapped;
- } else {
- in.addr = *(struct in6_addr *)addr;
- }
-
b = siphash_20b((uint8_t *)&in, c->tcp.hash_secret);
return (unsigned int)(b % TCP_HASH_TABLE_SIZE);
@@ -1348,7 +1330,7 @@ static void tcp_hash_insert(const struct ctx *c, struct tcp_conn
*conn)
{
int b;
- b = tcp_hash(c, AF_INET6, &conn->a.a6, conn->tap_port, conn->sock_port);
+ b = tcp_hash(c, &conn->a.a6, conn->tap_port, conn->sock_port);
conn->next_index = tc_hash[b] ? tc_hash[b] - tc : -1;
tc_hash[b] = conn;
conn->hash_bucket = b;
@@ -1422,11 +1404,19 @@ static struct tcp_conn *tcp_hash_lookup(const struct ctx *c, int
af,
const void *addr,
in_port_t tap_port, in_port_t sock_port)
{
- int b = tcp_hash(c, af, addr, tap_port, sock_port);
+ struct in6_addr v4mapped;
struct tcp_conn *conn;
+ int b;
+
+ if (af == AF_INET) {
+ encode_ip4mapped_ip6(&v4mapped, addr);
+ addr = &v4mapped;
+ }
+
+ b = tcp_hash(c, addr, tap_port, sock_port);
for (conn = tc_hash[b]; conn; conn = CONN_OR_NULL(conn->next_index)) {
- if (tcp_hash_match(conn, af, addr, tap_port, sock_port))
+ if (tcp_hash_match(conn, addr, tap_port, sock_port))
return conn;
}
--
2.38.1