[PATCH] 2.4.19 Bluetooth [2/5] L2CAP fixes

Maksim (maxk@qualcomm.com)
04 Aug 2002 03:53:45 -0700


L2CAP fixes and updates.

- Locking fixes

- Support for connectionless channels (datagram sockets)

- Support for shutdown() syscall

l2cap.c | 220 ++++++++++++++++++++++++++++++++++++++++++----------------------
1 files changed, 146 insertions(+), 74 deletions(-)

http://bluez.sourceforge.net/patches/patch-2.4.19-bluetooth-l2cap.gz

Please apply

Max

diff -urN -x 'hci*' -x 'sco*' -x 'af_*' linux.orig/net/bluetooth/l2cap.c linux/net/bluetooth/l2cap.c
--- linux.orig/net/bluetooth/l2cap.c Sat Aug 3 11:59:47 2002
+++ linux/net/bluetooth/l2cap.c Sat Aug 3 18:12:36 2002
@@ -25,9 +25,9 @@
/*
* BlueZ L2CAP core and sockets.
*
- * $Id: l2cap.c,v 1.8 2002/04/19 00:01:39 maxk Exp $
+ * $Id: l2cap.c,v 1.13 2002/07/27 19:04:15 maxk Exp $
*/
-#define VERSION "2.0"
+#define VERSION "2.1"

#include <linux/config.h>
#include <linux/module.h>
@@ -51,6 +51,7 @@

#include <asm/system.h>
#include <asm/uaccess.h>
+#include <asm/unaligned.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
@@ -234,32 +235,26 @@
}

/* -------- Socket interface ---------- */
-static struct sock *__l2cap_get_sock_by_addr(struct sockaddr_l2 *addr)
+static struct sock *__l2cap_get_sock_by_addr(__u16 psm, bdaddr_t *src)
{
- bdaddr_t *src = &addr->l2_bdaddr;
- __u16 psm = addr->l2_psm;
struct sock *sk;
-
for (sk = l2cap_sk_list.head; sk; sk = sk->next) {
if (l2cap_pi(sk)->psm == psm &&
- !bacmp(&bluez_pi(sk)->src, src))
+ !bacmp(&bluez_pi(sk)->src, src))
break;
}
-
return sk;
}

-/* Find socket listening on psm and source bdaddr.
+/* Find socket with psm and source bdaddr.
* Returns closest match.
*/
-static struct sock *l2cap_get_sock_listen(bdaddr_t *src, __u16 psm)
+static struct sock *__l2cap_get_sock_by_psm(int state, __u16 psm, bdaddr_t *src)
{
struct sock *sk, *sk1 = NULL;

- read_lock(&l2cap_sk_list.lock);
-
for (sk = l2cap_sk_list.head; sk; sk = sk->next) {
- if (sk->state != BT_LISTEN)
+ if (state && sk->state != state)
continue;

if (l2cap_pi(sk)->psm == psm) {
@@ -272,9 +267,19 @@
sk1 = sk;
}
}
+ return sk ? sk : sk1;
+}

+/* Find socket with given address (psm, src).
+ * Returns locked socket */
+static inline struct sock *l2cap_get_sock_by_psm(int state, __u16 psm, bdaddr_t *src)
+{
+ struct sock *s;
+ read_lock(&l2cap_sk_list.lock);
+ s = __l2cap_get_sock_by_psm(state, psm, src);
+ if (s) bh_lock_sock(s);
read_unlock(&l2cap_sk_list.lock);
- return sk ? sk : sk1;
+ return s;
}

static void l2cap_sock_destruct(struct sock *sk)
@@ -330,6 +335,7 @@

case BT_CONNECTED:
case BT_CONFIG:
+ case BT_CONNECT2:
if (sk->type == SOCK_SEQPACKET) {
struct l2cap_conn *conn = l2cap_pi(sk)->conn;
l2cap_disconn_req req;
@@ -346,7 +352,6 @@
break;

case BT_CONNECT:
- case BT_CONNECT2:
case BT_DISCONN:
l2cap_chan_del(sk, reason);
break;
@@ -377,7 +382,6 @@

if (parent) {
sk->type = parent->type;
-
pi->imtu = l2cap_pi(parent)->imtu;
pi->omtu = l2cap_pi(parent)->omtu;
pi->link_mode = l2cap_pi(parent)->link_mode;
@@ -425,7 +429,7 @@

sock->state = SS_UNCONNECTED;

- if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_RAW)
+ if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
return -ESOCKTNOSUPPORT;

sock->ops = &l2cap_sock_ops;
@@ -455,20 +459,17 @@
goto done;
}

- write_lock(&l2cap_sk_list.lock);
-
- if (la->l2_psm && __l2cap_get_sock_by_addr(la)) {
+ write_lock_bh(&l2cap_sk_list.lock);
+ if (la->l2_psm && __l2cap_get_sock_by_addr(la->l2_psm, &la->l2_bdaddr)) {
err = -EADDRINUSE;
- goto unlock;
+ } else {
+ /* Save source address */
+ bacpy(&bluez_pi(sk)->src, &la->l2_bdaddr);
+ l2cap_pi(sk)->psm = la->l2_psm;
+ sk->state = BT_BOUND;
}

- /* Save source address */
- bacpy(&bluez_pi(sk)->src, &la->l2_bdaddr);
- l2cap_pi(sk)->psm = la->l2_psm;
- sk->state = BT_BOUND;
-
-unlock:
- write_unlock(&l2cap_sk_list.lock);
+ write_unlock_bh(&l2cap_sk_list.lock);

done:
release_sock(sk);
@@ -631,7 +632,6 @@
bacpy(&la->l2_bdaddr, &bluez_pi(sk)->src);

la->l2_psm = l2cap_pi(sk)->psm;
-
return 0;
}

@@ -648,6 +648,10 @@
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;

+ /* Check outgoing MTU */
+ if (len > l2cap_pi(sk)->omtu)
+ return -EINVAL;
+
lock_sock(sk);

if (sk->state == BT_CONNECTED)
@@ -693,7 +697,7 @@
default:
err = -ENOPROTOOPT;
break;
- };
+ }

release_sock(sk);
return err;
@@ -745,20 +749,37 @@
default:
err = -ENOPROTOOPT;
break;
- };
+ }

release_sock(sk);
return err;
}

+static int l2cap_sock_shutdown(struct socket *sock, int how)
+{
+ struct sock *sk = sock->sk;
+
+ BT_DBG("sock %p, sk %p", sock, sk);
+
+ if (!sk) return 0;
+
+ l2cap_sock_clear_timer(sk);
+
+ lock_sock(sk);
+ sk->shutdown = SHUTDOWN_MASK;
+ __l2cap_sock_close(sk, ECONNRESET);
+ release_sock(sk);
+
+ return 0;
+}
+
static int l2cap_sock_release(struct socket *sock)
{
struct sock *sk = sock->sk;

BT_DBG("sock %p, sk %p", sock, sk);

- if (!sk)
- return 0;
+ if (!sk) return 0;

sock_orphan(sk);
l2cap_sock_close(sk);
@@ -769,24 +790,20 @@
static struct sock * __l2cap_get_chan_by_dcid(struct l2cap_chan_list *l, __u16 cid)
{
struct sock *s;
-
for (s = l->head; s; s = l2cap_pi(s)->next_c) {
if (l2cap_pi(s)->dcid == cid)
break;
}
-
return s;
}

static struct sock *__l2cap_get_chan_by_scid(struct l2cap_chan_list *l, __u16 cid)
{
struct sock *s;
-
for (s = l->head; s; s = l2cap_pi(s)->next_c) {
if (l2cap_pi(s)->scid == cid)
break;
}
-
return s;
}

@@ -852,10 +869,15 @@
l2cap_pi(sk)->conn = conn;

if (sk->type == SOCK_SEQPACKET) {
- /* Alloc CID for normal socket */
+ /* Alloc CID for connection-oriented socket */
l2cap_pi(sk)->scid = l2cap_alloc_cid(l);
+ } else if (sk->type == SOCK_DGRAM) {
+ /* Connectionless socket */
+ l2cap_pi(sk)->scid = 0x0002;
+ l2cap_pi(sk)->dcid = 0x0002;
+ l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
} else {
- /* Raw socket can send only signalling messages */
+ /* Raw socket can send/recv signalling messages only */
l2cap_pi(sk)->scid = 0x0001;
l2cap_pi(sk)->dcid = 0x0001;
l2cap_pi(sk)->omtu = L2CAP_DEFAULT_MTU;
@@ -986,25 +1008,31 @@
{
struct l2cap_conn *conn = l2cap_pi(sk)->conn;
struct sk_buff *skb, **frag;
- int err, size, count, sent=0;
+ int err, hlen, count, sent=0;
l2cap_hdr *lh;

- /* Check outgoing MTU */
- if (len > l2cap_pi(sk)->omtu)
- return -EINVAL;
-
BT_DBG("sk %p len %d", sk, len);

/* First fragment (with L2CAP header) */
- count = MIN(conn->mtu - L2CAP_HDR_SIZE, len);
- size = L2CAP_HDR_SIZE + count;
- if (!(skb = bluez_skb_send_alloc(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)))
+ if (sk->type == SOCK_DGRAM)
+ hlen = L2CAP_HDR_SIZE + 2;
+ else
+ hlen = L2CAP_HDR_SIZE;
+
+ count = MIN(conn->mtu - hlen, len);
+
+ skb = bluez_skb_send_alloc(sk, hlen + count,
+ msg->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb)
return err;

/* Create L2CAP header */
lh = (l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
- lh->len = __cpu_to_le16(len);
lh->cid = __cpu_to_le16(l2cap_pi(sk)->dcid);
+ lh->len = __cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
+
+ if (sk->type == SOCK_DGRAM)
+ put_unaligned(l2cap_pi(sk)->psm, (__u16 *) skb_put(skb, 2));

if (memcpy_fromiovec(skb_put(skb, count), msg->msg_iov, count)) {
err = -EFAULT;
@@ -1317,37 +1345,41 @@
BT_DBG("psm 0x%2.2x scid 0x%4.4x", psm, scid);

/* Check if we have socket listening on psm */
- if (!(parent = l2cap_get_sock_listen(conn->src, psm))) {
+ parent = l2cap_get_sock_by_psm(BT_LISTEN, psm, conn->src);
+ if (!parent) {
result = L2CAP_CR_BAD_PSM;
- goto resp;
+ goto sendresp;
}

- write_lock(&list->lock);
- bh_lock_sock(parent);
-
result = L2CAP_CR_NO_MEM;

- /* Check if we already have channel with that dcid */
- if (__l2cap_get_chan_by_dcid(list, scid))
- goto unlock;
-
/* Check for backlog size */
if (parent->ack_backlog > parent->max_ack_backlog) {
BT_DBG("backlog full %d", parent->ack_backlog);
- goto unlock;
+ goto response;
}

- if (!(sk = l2cap_sock_alloc(NULL, BTPROTO_L2CAP, GFP_ATOMIC)))
- goto unlock;
+ sk = l2cap_sock_alloc(NULL, BTPROTO_L2CAP, GFP_ATOMIC);
+ if (!sk)
+ goto response;

- l2cap_sock_init(sk, parent);
+ write_lock(&list->lock);

+ /* Check if we already have channel with that dcid */
+ if (__l2cap_get_chan_by_dcid(list, scid)) {
+ write_unlock(&list->lock);
+ sk->zapped = 1;
+ l2cap_sock_kill(sk);
+ goto response;
+ }
+
+ hci_conn_hold(conn->hcon);
+
+ l2cap_sock_init(sk, parent);
bacpy(&bluez_pi(sk)->src, conn->src);
bacpy(&bluez_pi(sk)->dst, conn->dst);
l2cap_pi(sk)->psm = psm;
l2cap_pi(sk)->dcid = scid;
-
- hci_conn_hold(conn->hcon);

__l2cap_chan_add(conn, sk, parent);
dcid = l2cap_pi(sk)->scid;
@@ -1362,20 +1394,22 @@

if (l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT) {
if (!hci_conn_encrypt(conn->hcon))
- goto unlock;
+ goto done;
} else if (l2cap_pi(sk)->link_mode & L2CAP_LM_AUTH) {
if (!hci_conn_auth(conn->hcon))
- goto unlock;
+ goto done;
}

sk->state = BT_CONFIG;
result = status = 0;

-unlock:
- bh_unlock_sock(parent);
+done:
write_unlock(&list->lock);

-resp:
+response:
+ bh_unlock_sock(parent);
+
+sendresp:
rsp.scid = __cpu_to_le16(scid);
rsp.dcid = __cpu_to_le16(dcid);
rsp.result = __cpu_to_le16(result);
@@ -1680,10 +1714,37 @@
return 0;
}

+static inline int l2cap_conless_channel(struct l2cap_conn *conn, __u16 psm, struct sk_buff *skb)
+{
+ struct sock *sk;
+
+ sk = l2cap_get_sock_by_psm(0, psm, conn->src);
+ if (!sk)
+ goto drop;
+
+ BT_DBG("sk %p, len %d", sk, skb->len);
+
+ if (sk->state != BT_BOUND && sk->state != BT_CONNECTED)
+ goto drop;
+
+ if (l2cap_pi(sk)->imtu < skb->len)
+ goto drop;
+
+ if (!sock_queue_rcv_skb(sk, skb))
+ goto done;
+
+drop:
+ kfree_skb(skb);
+
+done:
+ if (sk) bh_unlock_sock(sk);
+ return 0;
+}
+
static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
{
l2cap_hdr *lh = (l2cap_hdr *) skb->data;
- __u16 cid, len;
+ __u16 cid, psm, len;

skb_pull(skb, L2CAP_HDR_SIZE);
cid = __le16_to_cpu(lh->cid);
@@ -1691,10 +1752,21 @@

BT_DBG("len %d, cid 0x%4.4x", len, cid);

- if (cid == 0x0001)
+ switch (cid) {
+ case 0x0001:
l2cap_sig_channel(conn, skb);
- else
+ break;
+
+ case 0x0002:
+ psm = get_unaligned((__u16 *) skb->data);
+ skb_pull(skb, 2);
+ l2cap_conless_channel(conn, psm, skb);
+ break;
+
+ default:
l2cap_data_channel(conn, cid, skb);
+ break;
+ }
}

/* ------------ L2CAP interface with lower layer (HCI) ------------- */
@@ -1934,7 +2006,7 @@
struct sock *sk;
char *ptr = buf;

- write_lock(&list->lock);
+ read_lock_bh(&list->lock);

for (sk = list->head; sk; sk = sk->next) {
pi = l2cap_pi(sk);
@@ -1944,7 +2016,7 @@
pi->link_mode);
}

- write_unlock(&list->lock);
+ read_unlock_bh(&list->lock);

ptr += sprintf(ptr, "\n");
return ptr - buf;
@@ -1987,7 +2059,7 @@
poll: bluez_sock_poll,
socketpair: sock_no_socketpair,
ioctl: sock_no_ioctl,
- shutdown: sock_no_shutdown,
+ shutdown: l2cap_sock_shutdown,
setsockopt: l2cap_sock_setsockopt,
getsockopt: l2cap_sock_getsockopt,
mmap: sock_no_mmap

-
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