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From: David Gibson <david@gibson.dropbear.id.au>
To: passt-dev@passt.top, Stefano Brivio <sbrivio@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 06/10] tcp:  Unify IPv4 and IPv6 paths for hashing and matching
Date: Fri,  4 Nov 2022 19:43:29 +1100	[thread overview]
Message-ID: <20221104084333.3761760-7-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20221104084333.3761760-1-david@gibson.dropbear.id.au>

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@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;
 	}
 
-- 
@@ -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


  parent reply	other threads:[~2022-11-04  8:43 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-04  8:43 [PATCH 00/10] RFC: Preliminaries for using share IPv4 & IPv6 sockets David Gibson
2022-11-04  8:43 ` [PATCH 01/10] tcp: no v6 flag in ref David Gibson
2022-11-07 18:07   ` Stefano Brivio
2022-11-08  0:35     ` David Gibson
2022-11-04  8:43 ` [PATCH 02/10] tcp: Helper to encode IPv4-mapped IPv6 addresses David Gibson
2022-11-07 18:08   ` Stefano Brivio
2022-11-08  0:46     ` David Gibson
2022-11-04  8:43 ` [PATCH 03/10] tcp: Partially unify IPv4 and IPv6 paths in tcp_hash_match() David Gibson
2022-11-07 18:08   ` Stefano Brivio
2022-11-08  0:51     ` David Gibson
2022-11-04  8:43 ` [PATCH 04/10] tcp: Hash IPv4 and IPv4-mapped-IPv6 addresses the same David Gibson
2022-11-04  8:43 ` [PATCH 05/10] tcp: Take tcp_hash_insert() address from struct tcp_conn David Gibson
2022-11-04  8:43 ` David Gibson [this message]
2022-11-04  8:43 ` [PATCH 07/10] tcp: Remove ugly address union " David Gibson
2022-11-07 18:08   ` Stefano Brivio
2022-11-08  0:54     ` David Gibson
2022-11-04  8:43 ` [PATCH 08/10] tcp: Unify initial sequence numbers for IPv4 and IPv6 David Gibson
2022-11-04  8:43 ` [PATCH 09/10] tcp: Have tcp_seq_init() take its parameters from struct tcp_conn David Gibson
2022-11-04  8:43 ` [PATCH 10/10] tcp: Fix small error in tcp_seq_init() time handling David Gibson
2022-11-07 18:08   ` Stefano Brivio
2022-11-08  0:59     ` David Gibson
2022-11-04  8:47 ` [PATCH 00/10] RFC: Preliminaries for using share IPv4 & IPv6 sockets Stefano Brivio

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