diff options
| author | Archie Pusaka <apusaka@chromium.org> | 2020-04-14 16:08:40 +0800 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2020-05-13 10:03:51 +0200 |
| commit | 5b440676c15bbe1a40f2546ec92db83ed66d9e22 (patch) | |
| tree | 5c5e27362bbf9d47b19112ed96a2b36b5683a2a6 /net/bluetooth | |
| parent | adf1d6926444029396861413aba8a0f2a805742a (diff) | |
| download | linux-5b440676c15bbe1a40f2546ec92db83ed66d9e22.tar.gz linux-5b440676c15bbe1a40f2546ec92db83ed66d9e22.tar.bz2 linux-5b440676c15bbe1a40f2546ec92db83ed66d9e22.zip | |
Bluetooth: L2CAP: add support for waiting disconnection resp
Whenever we disconnect a L2CAP connection, we would immediately
report a disconnection event (EPOLLHUP) to the upper layer, without
waiting for the response of the other device.
This patch offers an option to wait until we receive a disconnection
response before reporting disconnection event, by using the "how"
parameter in l2cap_sock_shutdown(). Therefore, upper layer can opt
to wait for disconnection response by shutdown(sock, SHUT_WR).
This can be used to enforce proper disconnection order in HID,
where the disconnection of the interrupt channel must be complete
before attempting to disconnect the control channel.
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 1cea42ee1e92..a995d2c51fa7 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1271,14 +1271,21 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) struct l2cap_conn *conn; int err = 0; - BT_DBG("sock %p, sk %p", sock, sk); + BT_DBG("sock %p, sk %p, how %d", sock, sk, how); + + /* 'how' parameter is mapped to sk_shutdown as follows: + * SHUT_RD (0) --> RCV_SHUTDOWN (1) + * SHUT_WR (1) --> SEND_SHUTDOWN (2) + * SHUT_RDWR (2) --> SHUTDOWN_MASK (3) + */ + how++; if (!sk) return 0; lock_sock(sk); - if (sk->sk_shutdown) + if ((sk->sk_shutdown & how) == how) goto shutdown_already; BT_DBG("Handling sock shutdown"); @@ -1301,11 +1308,20 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) * has already been actioned to close the L2CAP * link such as by l2cap_disconnection_req(). */ - if (sk->sk_shutdown) - goto has_shutdown; + if ((sk->sk_shutdown & how) == how) + goto shutdown_matched; } - sk->sk_shutdown = SHUTDOWN_MASK; + /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN + * is already set + */ + if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) { + sk->sk_shutdown |= RCV_SHUTDOWN; + if ((sk->sk_shutdown & how) == how) + goto shutdown_matched; + } + + sk->sk_shutdown |= SEND_SHUTDOWN; release_sock(sk); l2cap_chan_lock(chan); @@ -1335,7 +1351,7 @@ static int l2cap_sock_shutdown(struct socket *sock, int how) err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime); -has_shutdown: +shutdown_matched: l2cap_chan_put(chan); sock_put(sk); @@ -1363,7 +1379,7 @@ static int l2cap_sock_release(struct socket *sock) bt_sock_unlink(&l2cap_sk_list, sk); - err = l2cap_sock_shutdown(sock, 2); + err = l2cap_sock_shutdown(sock, SHUT_RDWR); chan = l2cap_pi(sk)->chan; l2cap_chan_hold(chan); |