Bluetooth: Add support for deferring L2CAP connection setup

In order to decide if listening L2CAP sockets should be accept()ed
the BD_ADDR of the remote device needs to be known. This patch adds
a socket option which defines a timeout for deferring the actual
connection setup.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index df1a95e185c6647e0758dce25b3d7a67cbb1cf2e..123efb46d3f5a568b7eafa2ace58e45dcef5583f 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -372,9 +372,17 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
                        rsp.dcid = cpu_to_le16(l2cap_pi(sk)->scid);
 
                        if (l2cap_check_link_mode(sk)) {
-                               sk->sk_state = BT_CONFIG;
-                               rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
-                               rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+                               if (bt_sk(sk)->defer_setup) {
+                                       struct sock *parent = bt_sk(sk)->parent;
+                                       rsp.result = cpu_to_le16(L2CAP_CR_PEND);
+                                       rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
+                                       parent->sk_data_ready(parent, 0);
+
+                               } else {
+                                       sk->sk_state = BT_CONFIG;
+                                       rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
+                                       rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+                               }
                        } else {
                                rsp.result = cpu_to_le16(L2CAP_CR_PEND);
                                rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
@@ -608,7 +616,6 @@ static void __l2cap_sock_close(struct sock *sk, int reason)
 
        case BT_CONNECTED:
        case BT_CONFIG:
-       case BT_CONNECT2:
                if (sk->sk_type == SOCK_SEQPACKET) {
                        struct l2cap_conn *conn = l2cap_pi(sk)->conn;
                        struct l2cap_disconn_req req;
@@ -624,6 +631,27 @@ static void __l2cap_sock_close(struct sock *sk, int reason)
                        l2cap_chan_del(sk, reason);
                break;
 
+       case BT_CONNECT2:
+               if (sk->sk_type == SOCK_SEQPACKET) {
+                       struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+                       struct l2cap_conn_rsp rsp;
+                       __u16 result;
+
+                       if (bt_sk(sk)->defer_setup)
+                               result = L2CAP_CR_SEC_BLOCK;
+                       else
+                               result = L2CAP_CR_BAD_PSM;
+
+                       rsp.scid   = cpu_to_le16(l2cap_pi(sk)->dcid);
+                       rsp.dcid   = cpu_to_le16(l2cap_pi(sk)->scid);
+                       rsp.result = cpu_to_le16(result);
+                       rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+                       l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
+                                       L2CAP_CONN_RSP, sizeof(rsp), &rsp);
+               } else
+                       l2cap_chan_del(sk, reason);
+               break;
+
        case BT_CONNECT:
        case BT_DISCONN:
                l2cap_chan_del(sk, reason);
@@ -653,6 +681,8 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
 
        if (parent) {
                sk->sk_type = parent->sk_type;
+               bt_sk(sk)->defer_setup = bt_sk(parent)->defer_setup;
+
                pi->imtu = l2cap_pi(parent)->imtu;
                pi->omtu = l2cap_pi(parent)->omtu;
                pi->link_mode = l2cap_pi(parent)->link_mode;
@@ -1106,6 +1136,33 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
        return err;
 }
 
+static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags)
+{
+       struct sock *sk = sock->sk;
+
+       lock_sock(sk);
+
+       if (sk->sk_state == BT_CONNECT2 && bt_sk(sk)->defer_setup) {
+               struct l2cap_conn_rsp rsp;
+
+               sk->sk_state = BT_CONFIG;
+
+               rsp.scid   = cpu_to_le16(l2cap_pi(sk)->dcid);
+               rsp.dcid   = cpu_to_le16(l2cap_pi(sk)->scid);
+               rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
+               rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
+               l2cap_send_cmd(l2cap_pi(sk)->conn, l2cap_pi(sk)->ident,
+                                       L2CAP_CONN_RSP, sizeof(rsp), &rsp);
+
+               release_sock(sk);
+               return 0;
+       }
+
+       release_sock(sk);
+
+       return bt_sock_recvmsg(iocb, sock, msg, len, flags);
+}
+
 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, int optlen)
 {
        struct sock *sk = sock->sk;
@@ -1156,6 +1213,7 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch
 {
        struct sock *sk = sock->sk;
        int err = 0;
+       u32 opt;
 
        BT_DBG("sk %p", sk);
 
@@ -1165,6 +1223,20 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch
        lock_sock(sk);
 
        switch (optname) {
+       case BT_DEFER_SETUP:
+               if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
+                       err = -EINVAL;
+                       break;
+               }
+
+               if (get_user(opt, (u32 __user *) optval)) {
+                       err = -EFAULT;
+                       break;
+               }
+
+               bt_sk(sk)->defer_setup = opt;
+               break;
+
        default:
                err = -ENOPROTOOPT;
                break;
@@ -1207,7 +1279,9 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, char __us
                break;
 
        case L2CAP_CONNINFO:
-               if (sk->sk_state != BT_CONNECTED) {
+               if (sk->sk_state != BT_CONNECTED &&
+                                       !(sk->sk_state == BT_CONNECT2 &&
+                                               bt_sk(sk)->defer_setup)) {
                        err = -ENOTCONN;
                        break;
                }
@@ -1246,6 +1320,17 @@ static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, ch
        lock_sock(sk);
 
        switch (optname) {
+       case BT_DEFER_SETUP:
+               if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
+                       err = -EINVAL;
+                       break;
+               }
+
+               if (put_user(bt_sk(sk)->defer_setup, (u32 __user *) optval))
+                       err = -EFAULT;
+
+               break;
+
        default:
                err = -ENOPROTOOPT;
                break;
@@ -1670,9 +1755,16 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
        if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) {
                if (l2cap_check_link_mode(sk)) {
-                       sk->sk_state = BT_CONFIG;
-                       result = L2CAP_CR_SUCCESS;
-                       status = L2CAP_CS_NO_INFO;
+                       if (bt_sk(sk)->defer_setup) {
+                               sk->sk_state = BT_CONNECT2;
+                               result = L2CAP_CR_PEND;
+                               status = L2CAP_CS_AUTHOR_PEND;
+                               parent->sk_data_ready(parent, 0);
+                       } else {
+                               sk->sk_state = BT_CONFIG;
+                               result = L2CAP_CR_SUCCESS;
+                               status = L2CAP_CS_NO_INFO;
+                       }
                } else {
                        sk->sk_state = BT_CONNECT2;
                        result = L2CAP_CR_PEND;
@@ -2494,7 +2586,7 @@ static const struct proto_ops l2cap_sock_ops = {
        .accept         = l2cap_sock_accept,
        .getname        = l2cap_sock_getname,
        .sendmsg        = l2cap_sock_sendmsg,
-       .recvmsg        = bt_sock_recvmsg,
+       .recvmsg        = l2cap_sock_recvmsg,
        .poll           = bt_sock_poll,
        .ioctl          = bt_sock_ioctl,
        .mmap           = sock_no_mmap,