tcp: Split pool lookup from creating new sockets in tcp_conn_new_sock()

tcp_conn_new_sock() first looks for a socket in a pre-opened pool, then if
that's empty creates a new socket in the init namespace.  Both parts of
this are duplicated in other places: the pool lookup logic is duplicated in
tcp_splice_new(), and the socket opening logic is duplicated in
tcp_sock_refill_pool().

Split the function into separate parts so we can remove both these
duplications.

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 2023-02-14 10:48:22 +11:00 committed by Stefano Brivio
parent 912d37cd5b
commit dc467d526f
3 changed files with 31 additions and 31 deletions

53
tcp.c
View file

@ -1858,24 +1858,35 @@ static void tcp_seq_init(const struct ctx *c, struct tcp_tap_conn *conn,
}
/**
* tcp_conn_new_sock() - Get socket for new connection from pool or make new one
* tcp_conn_pool_sock() - Get socket for new connection from pre-opened pool
* @pool: Pool of pre-opened sockets
*
* Return: socket number if available, negative code if pool is empty
*/
int tcp_conn_pool_sock(int pool[])
{
int s = -1, i;
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++) {
SWAP(s, pool[i]);
if (s >= 0)
return s;
}
return -1;
}
/**
* tcp_conn_new_sock() - Open and prepare new socket for connection
* @c: Execution context
* @af: Address family
*
* Return: socket number if available, negative code if socket creation failed
* Return: socket number on success, negative code if socket creation failed
*/
static int tcp_conn_new_sock(const struct ctx *c, sa_family_t af)
{
int *p = af == AF_INET6 ? init_sock_pool6 : init_sock_pool4, i, s = -1;
int s;
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++, p++) {
SWAP(s, *p);
if (s >= 0)
break;
}
if (s < 0)
s = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
s = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
if (s > SOCKET_MAX) {
close(s);
@ -1936,6 +1947,7 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
const struct tcphdr *th, const char *opts,
size_t optlen, const struct timespec *now)
{
int *pool = af == AF_INET6 ? init_sock_pool6 : init_sock_pool4;
struct sockaddr_in addr4 = {
.sin_family = AF_INET,
.sin_port = th->dest,
@ -1954,8 +1966,9 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
if (c->tcp.conn_count >= TCP_MAX_CONNS)
return;
if ((s = tcp_conn_new_sock(c, af)) < 0)
return;
if ((s = tcp_conn_pool_sock(pool)) < 0)
if ((s = tcp_conn_new_sock(c, af)) < 0)
return;
if (!c->no_map_gw) {
if (af == AF_INET && IN4_ARE_ADDR_EQUAL(addr, &c->ip4.gw))
@ -3016,20 +3029,10 @@ void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af)
int i;
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++) {
int *s = &pool[i];
if (*s >= 0)
if (pool[i] >= 0)
break;
*s = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
if (*s > SOCKET_MAX) {
close(*s);
*s = -1;
return;
}
if (*s >= 0)
tcp_sock_set_bufsize(c, *s);
pool[i] = tcp_conn_new_sock(c, af);
}
}

View file

@ -192,6 +192,7 @@ void tcp_splice_conn_update(struct ctx *c, struct tcp_splice_conn *new);
void tcp_table_compact(struct ctx *c, union tcp_conn *hole);
void tcp_splice_destroy(struct ctx *c, union tcp_conn *conn_union);
void tcp_splice_timer(struct ctx *c, union tcp_conn *conn_union);
int tcp_conn_pool_sock(int pool[]);
void tcp_sock_refill_pool(const struct ctx *c, int pool[], int af);
void tcp_splice_refill(const struct ctx *c);

View file

@ -451,18 +451,14 @@ static int tcp_splice_connect_ns(void *arg)
static int tcp_splice_new(const struct ctx *c, struct tcp_splice_conn *conn,
in_port_t port, int outbound)
{
int *p, i, s = -1;
int *p, s = -1;
if (outbound)
p = CONN_V6(conn) ? init_sock_pool6 : init_sock_pool4;
else
p = CONN_V6(conn) ? ns_sock_pool6 : ns_sock_pool4;
for (i = 0; i < TCP_SOCK_POOL_SIZE; i++, p++) {
SWAP(s, *p);
if (s >= 0)
break;
}
s = tcp_conn_pool_sock(p);
/* No socket available in namespace: create a new one for connect() */
if (s < 0 && !outbound) {