2012-04-12 15:30:50

by Mikel Astiz

Subject: [PATCH] Bluetooth: Fix ADDRINUSE check in SCO sockets

From: Mikel Astiz <[email protected]>

The ADDRINUSE error should be returned only when the SCO socket is being
used as a server. This means it should be checked in sco_sock_listen()
instead of in sco_sock_bind(), because in the later we can't know if it
is a server or not.

This patch is required in order to use multiple SCO connections in the
same Bluetooth adapter.

Signed-off-by: Mikel Astiz <[email protected]>
---
net/bluetooth/sco.c | 49 ++++++++++++++++++++++++++++++-------------------
1 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 8bf26d1..3a81d81 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -278,17 +278,30 @@ drop:
}

/* -------- Socket interface ---------- */
-static struct sock *__sco_get_sock_by_addr(bdaddr_t *ba)
+static int __sco_is_addr_in_use(bdaddr_t *src)
{
struct sock *sk;
struct hlist_node *node;

- sk_for_each(sk, node, &sco_sk_list.head)
- if (!bacmp(&bt_sk(sk)->src, ba))
- goto found;
- sk = NULL;
-found:
- return sk;
+ sk_for_each(sk, node, &sco_sk_list.head) {
+ if (sk->sk_state != BT_LISTEN)
+ continue;
+
+ /* Exact match */
+ if (!bacmp(&bt_sk(sk)->src, src))
+ return 1;
+
+ /* Closest match */
+ if (!bacmp(&bt_sk(sk)->src, BDADDR_ANY))
+ return 1;
+
+ /* Match any if given src is BDADDR_ANY */
+ if (!bacmp(src, BDADDR_ANY))
+ return 1;
+ }
+
+ /* No match found so address is free */
+ return 0;
}

/* Find socket listening on source bdaddr.
@@ -467,7 +480,6 @@ static int sco_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_le
{
struct sockaddr_sco *sa = (struct sockaddr_sco *) addr;
struct sock *sk = sock->sk;
- bdaddr_t *src = &sa->sco_bdaddr;
int err = 0;

BT_DBG("sk %p %s", sk, batostr(&sa->sco_bdaddr));
@@ -482,17 +494,9 @@ static int sco_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_le
goto done;
}

- write_lock(&sco_sk_list.lock);
-
- if (bacmp(src, BDADDR_ANY) && __sco_get_sock_by_addr(src)) {
- err = -EADDRINUSE;
- } else {
- /* Save source address */
- bacpy(&bt_sk(sk)->src, &sa->sco_bdaddr);
- sk->sk_state = BT_BOUND;
- }
-
- write_unlock(&sco_sk_list.lock);
+ /* Save source address */
+ bacpy(&bt_sk(sk)->src, &sa->sco_bdaddr);
+ sk->sk_state = BT_BOUND;

done:
release_sock(sk);
@@ -543,17 +547,24 @@ static int sco_sock_listen(struct socket *sock, int backlog)
BT_DBG("sk %p backlog %d", sk, backlog);

lock_sock(sk);
+ write_lock(&sco_sk_list.lock);

if (sk->sk_state != BT_BOUND || sock->type != SOCK_SEQPACKET) {
err = -EBADFD;
goto done;
}

+ if (__sco_is_addr_in_use(&bt_sk(sk)->src)) {
+ err = -EADDRINUSE;
+ goto done;
+ }
+
sk->sk_max_ack_backlog = backlog;
sk->sk_ack_backlog = 0;
sk->sk_state = BT_LISTEN;

done:
+ write_unlock(&sco_sk_list.lock);
release_sock(sk);
return err;
}
--
1.7.7.6

2012-04-13 09:03:17

by Johan Hedberg

Subject: Re: [PATCH] Bluetooth: Fix ADDRINUSE check in SCO sockets

Hi Mikel,

On Thu, Apr 12, 2012, Mikel Astiz wrote:
> From: Mikel Astiz <[email protected]>
>
> The ADDRINUSE error should be returned only when the SCO socket is being
> used as a server. This means it should be checked in sco_sock_listen()
> instead of in sco_sock_bind(), because in the later we can't know if it
> is a server or not.
>
> This patch is required in order to use multiple SCO connections in the
> same Bluetooth adapter.
>
> Signed-off-by: Mikel Astiz <[email protected]>
> ---
> net/bluetooth/sco.c | 49 ++++++++++++++++++++++++++++++-------------------
> 1 files changed, 30 insertions(+), 19 deletions(-)

In general the patch looks ok to me except for a few things regarding
the helper function:

> +static int __sco_is_addr_in_use(bdaddr_t *src)

I suppose bool makes more sense than int here. The naming sounds also a
bit awkward to me (otoh maybe this is a normal convention): I'd just
leave out the "_is_" part or at least move it after "addr" to make it
sound more like normal English.

Johan