[PATCH 03/33] net: add sock_set_reuseaddr

Christoph Hellwig
2020-05-20T19:56:16Z

Add a helper to directly set the SO_REUSEADDR sockopt from kernel space
without going through a fake uaccess.

For this the iscsi target now has to formally depend on inet to avoid
a mostly theoretical compile failure. For actual operation it already
did depend on having ipv4 or ipv6 support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
---
drivers/infiniband/sw/siw/siw_cm.c | 18 +++++-------------
drivers/nvme/target/tcp.c | 8 +-------
drivers/target/iscsi/Kconfig | 2 +-
drivers/target/iscsi/iscsi_target_login.c | 9 +--------
fs/dlm/lowcomms.c | 6 +-----
include/net/sock.h | 2 ++
net/core/sock.c | 8 ++++++++
7 files changed, 19 insertions(+), 34 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c
index 559e5fd3bad8b..d1860f3e87401 100644
--- a/drivers/infiniband/sw/siw/siw_cm.c
+++ b/drivers/infiniband/sw/siw/siw_cm.c
@@ -1312,17 +1312,14 @@ static void siw_cm_llp_state_change(struct sock *sk)
static int kernel_bindconnect(struct socket *s, struct sockaddr *laddr,
struct sockaddr *raddr)
{
- int rv, flags = 0, s_val = 1;
+ int rv, flags = 0;
size_t size = laddr->sa_family == AF_INET ?
sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);

/*
* Make address available again asap.
*/
- rv = kernel_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&s_val,
- sizeof(s_val));
- if (rv < 0)
- return rv;
+ sock_set_reuseaddr(s->sk);

rv = s->ops->bind(s, laddr, size);
if (rv < 0)
@@ -1781,7 +1778,7 @@ int siw_create_listen(struct iw_cm_id *id, int backlog)
struct siw_cep *cep = NULL;
struct siw_device *sdev = to_siw_dev(id->device);
int addr_family = id->local_addr.ss_family;
- int rv = 0, s_val;
+ int rv = 0;

if (addr_family != AF_INET && addr_family != AF_INET6)
return -EAFNOSUPPORT;
@@ -1793,13 +1790,8 @@ int siw_create_listen(struct iw_cm_id *id, int backlog)
/*
* Allow binding local port when still in TIME_WAIT from last close.
*/
- s_val = 1;
- rv = kernel_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&s_val,
- sizeof(s_val));
- if (rv) {
- siw_dbg(id->device, "setsockopt error: %d\n", rv);
- goto error;
- }
+ sock_set_reuseaddr(s->sk);
+
if (addr_family == AF_INET) {
struct sockaddr_in *laddr = &to_sockaddr_in(id->local_addr);

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index f0da04e960f40..40757a63f4553 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1632,6 +1632,7 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
port->sock->sk->sk_user_data = port;
port->data_ready = port->sock->sk->sk_data_ready;
port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
+ sock_set_reuseaddr(port->sock->sk);

opt = 1;
ret = kernel_setsockopt(port->sock, IPPROTO_TCP,
@@ -1641,13 +1642,6 @@ static int nvmet_tcp_add_port(struct nvmet_port *nport)
goto err_sock;
}

- ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_REUSEADDR,
- (char *)&opt, sizeof(opt));
- if (ret) {
- pr_err("failed to set SO_REUSEADDR sock opt %d\n", ret);
- goto err_sock;
- }
-
if (so_priority > 0) {
ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_PRIORITY,
(char *)&so_priority, sizeof(so_priority));
diff --git a/drivers/target/iscsi/Kconfig b/drivers/target/iscsi/Kconfig
index 1f93ea3813536..922484ea4e304 100644
--- a/drivers/target/iscsi/Kconfig
+++ b/drivers/target/iscsi/Kconfig
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config ISCSI_TARGET
tristate "Linux-iSCSI.org iSCSI Target Mode Stack"
- depends on NET
+ depends on INET
select CRYPTO
select CRYPTO_CRC32C
select CRYPTO_CRC32C_INTEL if X86
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 731ee67fe914b..91acb3f07b4cc 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -909,14 +909,7 @@ int iscsit_setup_np(
}
}

- /* FIXME: Someone please explain why this is endian-safe */
- ret = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
- (char *)&opt, sizeof(opt));
- if (ret < 0) {
- pr_err("kernel_setsockopt() for SO_REUSEADDR"
- " failed\n");
- goto fail;
- }
+ sock_set_reuseaddr(sock->sk);

ret = kernel_setsockopt(sock, IPPROTO_IP, IP_FREEBIND,
(char *)&opt, sizeof(opt));
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index f13dad0fd9ef3..88f2574ca63ad 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -1127,12 +1127,8 @@ static struct socket *tcp_create_listen_sock(struct connection *con,
kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
sizeof(one));

- result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
- (char *)&one, sizeof(one));
+ sock_set_reuseaddr(sock->sk);

- if (result < 0) {
- log_print("Failed to set SO_REUSEADDR on socket: %d", result);
- }
write_lock_bh(&sock->sk->sk_callback_lock);
sock->sk->sk_user_data = con;
save_listen_callbacks(sock);
diff --git a/include/net/sock.h b/include/net/sock.h
index 3e8c6d4b4b59f..2ec085044790c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2688,4 +2688,6 @@ static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)

void sock_def_readable(struct sock *sk);

+void sock_set_reuseaddr(struct sock *sk);
+
#endif /* _SOCK_H */
diff --git a/net/core/sock.c b/net/core/sock.c
index fd85e651ce284..18eb84fdf5fbe 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -712,6 +712,14 @@ bool sk_mc_loop(struct sock *sk)
}
EXPORT_SYMBOL(sk_mc_loop);

+void sock_set_reuseaddr(struct sock *sk)
+{
+ lock_sock(sk);
+ sk->sk_reuse = SK_CAN_REUSE;
+ release_sock(sk);
+}
+EXPORT_SYMBOL(sock_set_reuseaddr);
+
/*
* This is meant for all protocols to use and covers goings on
* at the socket level. Everything here is generic.
--
2.26.2