The commit f396922d862a added a check to not allow changing
SO_REUSEADDR/SO_REUSEPORT on bound sockets. First, it doesn't
take into account that TCP_REPAIR changes SO_REUSEADDR. Second, now it
is impossible to restore a socket state and set SO_REUSEADDR,
because the kernel always sets SO_REUSEADDR into zero after disabling
the repair mode.
Currently, sk_reuse can have three values: SK_NO_REUSE, SK_CAN_REUSE,
SK_FORCE_REUSE. SK_CAN_REUSE is set by SOL_REUSEADDR. SK_FORCE_REUSE is
used to ignore bind conflicts for sockets in the repair mode.
This patch makes sk->sk_reuse back into a boolean and adds
sk->sk_force_reuse to track SK_FORCE_REUSE separatly.
In this case, the tcp_repair mode doesn't affect sk_reuse and
it's value can be set before switching a socketn into the repair mode.
Fixes: f396922d862a ("net: do not allow changing SO_REUSEADDR/SO_REUSEPORT on
bound sockets")
Cc: Maciej Żenczykowski <m...@google.com>
Cc: Eric Dumazet <eduma...@google.com>
Signed-off-by: Andrei Vagin <ava...@openvz.org>
---
include/net/sock.h | 13 ++++---------
net/ipv4/inet_connection_sock.c | 2 +-
net/ipv4/tcp.c | 4 ++--
3 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index b3b75419eafe..8ad19286ab9e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -130,6 +130,7 @@ typedef __u64 __bitwise __addrpair;
* @skc_family: network address family
* @skc_state: Connection state
* @skc_reuse: %SO_REUSEADDR setting
+ * @skc_force_reuse: ignore bind conflicts
* @skc_reuseport: %SO_REUSEPORT setting
* @skc_bound_dev_if: bound device index if != 0
* @skc_bind_node: bind hash linkage for various protocol lookup tables
@@ -174,7 +175,8 @@ struct sock_common {
unsigned short skc_family;
volatile unsigned char skc_state;
- unsigned char skc_reuse:4;
+ unsigned char skc_reuse:1;
+ unsigned char skc_force_reuse:1;
unsigned char skc_reuseport:1;
unsigned char skc_ipv6only:1;
unsigned char skc_net_refcnt:1;
@@ -339,6 +341,7 @@ struct sock {
#define sk_family __sk_common.skc_family
#define sk_state __sk_common.skc_state
#define sk_reuse __sk_common.skc_reuse
+#define sk_force_reuse __sk_common.skc_force_reuse
#define sk_reuseport __sk_common.skc_reuseport
#define sk_ipv6only __sk_common.skc_ipv6only
#define sk_net_refcnt __sk_common.skc_net_refcnt
@@ -502,16 +505,8 @@ enum sk_pacing {
#define rcu_dereference_sk_user_data(sk)
rcu_dereference(__sk_user_data((sk)))
#define rcu_assign_sk_user_data(sk, ptr)
rcu_assign_pointer(__sk_user_data((sk)), ptr)
-/*
- * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
- * or not whether his port will be reused by someone else. SK_FORCE_REUSE
- * on a socket means that the socket will reuse everybody else's port
- * without looking at the other's sk_reuse value.
- */
-
#define SK_NO_REUSE 0
#define SK_CAN_REUSE 1
-#define SK_FORCE_REUSE 2
int sk_set_peek_off(struct sock *sk, int val);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 33a88e045efd..2ac1c591b60c 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -306,7 +306,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
goto fail_unlock;
tb_found:
if (!hlist_empty(&tb->owners)) {
- if (sk->sk_reuse == SK_FORCE_REUSE)
+ if (sk->sk_force_reuse)
goto success;
if ((tb->fastreuse > 0 && reuse) ||
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2741953adaba..70bfdd5a2fc4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2810,11 +2810,11 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
err = -EPERM;
else if (val == 1) {
tp->repair = 1;
- sk->sk_reuse = SK_FORCE_REUSE;
+ sk->sk_force_reuse = 1;
tp->repair_queue = TCP_NO_QUEUE;
} else if (val == 0) {
tp->repair = 0;
- sk->sk_reuse = SK_NO_REUSE;
+ sk->sk_force_reuse = 0;
tcp_send_window_probe(sk);
} else
err = -EINVAL;
--
2.17.0
