[PATCH v2 1/5] tcp: Make a helper to refill each socket pool

[David Gibson <david@gibson.dropbear.id.au>]

tcp_sock_refill() contains two near-identical loops to refill the IPv4
and IPv6 socket pools.  In addition, if we get an error on the IPv4
pool we exit early and won't attempt to refill the IPv6 pool.  At
least theoretically, these are independent from each other and there's
value to filling up either pool without the other.  So, there's no
strong reason to give up on one because the other failed.

Address both of these with a helper function 'tcp_sock_refill_pool()' to
refill a single given pool.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c | 63 +++++++++++++++++++++++++++++++----------------------------
 1 file changed, 33 insertions(+), 30 deletions(-)

diff --git a/tcp.c b/tcp.c
index 8424d8e..5d13244 100644
--- a/tcp.c
+++ b/tcp.c
@@ -3009,6 +3009,34 @@ static int tcp_ns_socks_init(void *arg)
 	return 0;
 }
 
+/**
+ * tcp_sock_refill_pool() - Refill one pool of pre-opened sockets
+ * @c:		Execution context
+ * @pool:	Pool of sockets to refill
+ * @af:		Address family to use
+ */
+static 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)
+			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);
+	}
+}
+
 /**
  * struct tcp_sock_refill_arg - Arguments for tcp_sock_refill()
  * @c:		Execution context
@@ -3028,7 +3056,7 @@ struct tcp_sock_refill_arg {
 static int tcp_sock_refill(void *arg)
 {
 	struct tcp_sock_refill_arg *a = (struct tcp_sock_refill_arg *)arg;
-	int i, *p4, *p6;
+	int *p4, *p6;
 
 	if (a->ns) {
 		ns_enter(a->c);
@@ -3039,36 +3067,11 @@ static int tcp_sock_refill(void *arg)
 		p6 = init_sock_pool6;
 	}
 
-	for (i = 0; a->c->ifi4 && i < TCP_SOCK_POOL_SIZE; i++, p4++) {
-		if (*p4 >= 0)
-			break;
-
-		*p4 = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
-		if (*p4 > SOCKET_MAX) {
-			close(*p4);
-			*p4 = -1;
-			return -EIO;
-		}
-
-		if (*p4 >= 0)
-			tcp_sock_set_bufsize(a->c, *p4);
-	}
-
-	for (i = 0; a->c->ifi6 && i < TCP_SOCK_POOL_SIZE; i++, p6++) {
-		if (*p6 >= 0)
-			break;
-
-		*p6 = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK,
-			     IPPROTO_TCP);
-		if (*p6 > SOCKET_MAX) {
-			close(*p6);
-			*p6 = -1;
-			return -EIO;
-		}
+	if (a->c->ifi4)
+		tcp_sock_refill_pool(a->c, p4, AF_INET);
 
-		if (*p6 >= 0)
-			tcp_sock_set_bufsize(a->c, *p6);
-	}
+	if (a->c->ifi6)
+		tcp_sock_refill_pool(a->c, p6, AF_INET6);
 
 	return 0;
 }
-- 
@@ -3009,6 +3009,34 @@ static int tcp_ns_socks_init(void *arg)
 	return 0;
 }
 
+/**
+ * tcp_sock_refill_pool() - Refill one pool of pre-opened sockets
+ * @c:		Execution context
+ * @pool:	Pool of sockets to refill
+ * @af:		Address family to use
+ */
+static 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)
+			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);
+	}
+}
+
 /**
  * struct tcp_sock_refill_arg - Arguments for tcp_sock_refill()
  * @c:		Execution context
@@ -3028,7 +3056,7 @@ struct tcp_sock_refill_arg {
 static int tcp_sock_refill(void *arg)
 {
 	struct tcp_sock_refill_arg *a = (struct tcp_sock_refill_arg *)arg;
-	int i, *p4, *p6;
+	int *p4, *p6;
 
 	if (a->ns) {
 		ns_enter(a->c);
@@ -3039,36 +3067,11 @@ static int tcp_sock_refill(void *arg)
 		p6 = init_sock_pool6;
 	}
 
-	for (i = 0; a->c->ifi4 && i < TCP_SOCK_POOL_SIZE; i++, p4++) {
-		if (*p4 >= 0)
-			break;
-
-		*p4 = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
-		if (*p4 > SOCKET_MAX) {
-			close(*p4);
-			*p4 = -1;
-			return -EIO;
-		}
-
-		if (*p4 >= 0)
-			tcp_sock_set_bufsize(a->c, *p4);
-	}
-
-	for (i = 0; a->c->ifi6 && i < TCP_SOCK_POOL_SIZE; i++, p6++) {
-		if (*p6 >= 0)
-			break;
-
-		*p6 = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK,
-			     IPPROTO_TCP);
-		if (*p6 > SOCKET_MAX) {
-			close(*p6);
-			*p6 = -1;
-			return -EIO;
-		}
+	if (a->c->ifi4)
+		tcp_sock_refill_pool(a->c, p4, AF_INET);
 
-		if (*p6 >= 0)
-			tcp_sock_set_bufsize(a->c, *p6);
-	}
+	if (a->c->ifi6)
+		tcp_sock_refill_pool(a->c, p6, AF_INET6);
 
 	return 0;
 }
-- 
2.39.1