[CRIU] [PATCH 2/2] restore: don't desable tcp repair mode twice

[Andrey Vagin]

TCP repair mode should be disabled after unlocking connections.
Disabling of repair mode drops SO_REUSEADDR, so it should be restored.

Signed-off-by: Andrey Vagin <avagin at openvz.org>
---
 include/restorer.h |  2 +-
 include/sk-inet.h  |  5 +++++
 pie/restorer.c     | 17 ++++++++++++++---
 sk-inet.c          | 13 ++++++++-----
 sk-tcp.c           | 14 ++++++++------
 5 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/include/restorer.h b/include/restorer.h
index 097cba1..7366ad4 100644
--- a/include/restorer.h
+++ b/include/restorer.h
@@ -126,7 +126,7 @@ struct task_restore_core_args {
 	int				nr_rlim;
 	struct rlimit			rlims[RLIM_NLIMITS];
 
-	int				*rst_tcp_socks;
+	struct rst_tcp_sock		*rst_tcp_socks;
 	int				rst_tcp_socks_size;
 } __aligned(sizeof(long));
 
diff --git a/include/sk-inet.h b/include/sk-inet.h
index 522f549..6aa1b70 100644
--- a/include/sk-inet.h
+++ b/include/sk-inet.h
@@ -45,6 +45,11 @@ struct inet_sk_info {
 int inet_bind(int sk, struct inet_sk_info *);
 int inet_connect(int sk, struct inet_sk_info *);
 
+struct rst_tcp_sock {
+	int	sk;
+	bool	reuseaddr;
+};
+
 static inline void tcp_repair_off(int fd)
 {
 	int aux = 0;
diff --git a/pie/restorer.c b/pie/restorer.c
index 2034fb5..3f97d6f 100644
--- a/pie/restorer.c
+++ b/pie/restorer.c
@@ -274,15 +274,26 @@ static u64 restore_mapping(const VmaEntry *vma_entry)
 	return addr;
 }
 
-static void rst_tcp_socks_all(int *arr, int size)
+static void rst_tcp_repair_off(struct rst_tcp_sock *rts)
+{
+	int aux;
+
+	tcp_repair_off(rts->sk);
+
+	aux = rts->reuseaddr;
+	if (sys_setsockopt(rts->sk, SOL_SOCKET, SO_REUSEADDR, &aux, sizeof(aux)) < 0)
+		pr_perror("Failed to restore of SO_REUSEADDR on socket");
+}
+
+static void rst_tcp_socks_all(struct rst_tcp_sock *arr, int size)
 {
 	int i;
 
 	if (size == 0)
 		return;
 
-	for (i =0; arr[i] >= 0; i++)
-		tcp_repair_off(arr[i]);
+	for (i =0; arr[i].sk >= 0; i++)
+		rst_tcp_repair_off(arr + i);
 
 	sys_munmap(arr, size);
 }
diff --git a/sk-inet.c b/sk-inet.c
index b411c28..f8b47c0 100644
--- a/sk-inet.c
+++ b/sk-inet.c
@@ -439,16 +439,19 @@ static int post_open_inet_sk(struct file_desc *d, int sk)
 
 	ii = container_of(d, struct inet_sk_info, d);
 
+	/*
+	 * TCP sockets are handled at the last moment
+	 * after unlocking connections.
+	 */
+	if (tcp_connection(ii->ie))
+		return 0;
+
 	/* SO_REUSEADDR is set for all sockets */
-	if (!tcp_connection(ii->ie) && ii->ie->opts->reuseaddr)
+	if (ii->ie->opts->reuseaddr)
 		return 0;
 
 	futex_wait_until(&ii->port->users, 0);
 
-	/* Disabling repair mode drops SO_REUSEADDR */
-	if (tcp_connection(ii->ie))
-		tcp_repair_off(sk);
-
 	val = ii->ie->opts->reuseaddr;
 	if (restore_opt(sk, SOL_SOCKET, SO_REUSEADDR, &val))
 		return -1;
diff --git a/sk-tcp.c b/sk-tcp.c
index ebf9815..825f8b8 100644
--- a/sk-tcp.c
+++ b/sk-tcp.c
@@ -520,7 +520,7 @@ err:
  * rst_tcp_socks contains sockets in repair mode,
  * which will be off in restorer before resuming.
  */
-static int *rst_tcp_socks = NULL;
+static struct rst_tcp_sock *rst_tcp_socks = NULL;
 static int rst_tcp_socks_num = 0;
 int rst_tcp_socks_size = 0;
 
@@ -532,7 +532,7 @@ int rst_tcp_socks_remap(void *addr)
 		return 0;
 	}
 
-	rst_tcp_socks[rst_tcp_socks_num] = -1;
+	rst_tcp_socks[rst_tcp_socks_num].sk = -1;
 
 	ret = mmap(addr, rst_tcp_socks_size, PROT_READ | PROT_WRITE,
 			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
@@ -547,17 +547,19 @@ int rst_tcp_socks_remap(void *addr)
 	return 0;
 }
 
-static int rst_tcp_socks_add(int fd)
+static int rst_tcp_socks_add(int fd, bool reuseaddr)
 {
 	/* + 2 = ( new one + guard (-1) ) */
-	if ((rst_tcp_socks_num + 2) * sizeof(int) > rst_tcp_socks_size) {
+	if ((rst_tcp_socks_num + 2) * sizeof(struct rst_tcp_sock) > rst_tcp_socks_size) {
 		rst_tcp_socks_size += PAGE_SIZE;
 		rst_tcp_socks = xrealloc(rst_tcp_socks, rst_tcp_socks_size);
 		if (rst_tcp_socks == NULL)
 			return -1;
 	}
 
-	rst_tcp_socks[rst_tcp_socks_num++] = fd;
+	rst_tcp_socks[rst_tcp_socks_num].sk = fd;
+	rst_tcp_socks[rst_tcp_socks_num].reuseaddr = reuseaddr;
+	rst_tcp_socks_num++;
 	return 0;
 }
 
@@ -568,7 +570,7 @@ int restore_one_tcp(int fd, struct inet_sk_info *ii)
 	if (tcp_repair_on(fd))
 		return -1;
 
-	if (rst_tcp_socks_add(fd))
+	if (rst_tcp_socks_add(fd, ii->ie->opts->reuseaddr))
 		return -1;
 
 	if (restore_tcp_conn_state(fd, ii))
-- 
1.7.11.7