Phonet: receive pipe control requests as out-of-band data

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 50 insertions, 19 deletions

diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index c5dfecb207d2..d564d07cb797 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -137,14 +137,15 @@ static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code)
 
 /* Control requests are not sent by the pipe service and have a specific
  * message format. */
-static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code)
+static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
+                                gfp_t priority)
 {
         const struct pnpipehdr *oph = pnp_hdr(oskb);
         struct sk_buff *skb;
         struct pnpipehdr *ph;
         struct sockaddr_pn dst;
 
-        skb = alloc_skb(MAX_PNPIPE_HEADER + 4, GFP_ATOMIC);
+        skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
         if (!skb)
                 return -ENOMEM;
         skb_set_owner_w(skb, sk);
@@ -305,6 +306,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
         struct pep_sock *pn = pep_sk(sk);
         struct pnpipehdr *hdr = pnp_hdr(skb);
+        struct sk_buff_head *queue;
         int err = 0;
 
         BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
@@ -345,9 +347,11 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
                 break;
 
         case PNS_PEP_CTRL_REQ:
-                /* TODO */
-                pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR);
-                break;
+                if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX)
+                        break;
+                __skb_pull(skb, 4);
+                queue = &pn->ctrlreq_queue;
+                goto queue;
 
         case PNS_PIPE_DATA:
                 __skb_pull(skb, 3); /* Pipe data header */
@@ -363,13 +367,8 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
                         break;
                 }
                 pn->rx_credits--;
-                skb->dev = NULL;
-                skb_set_owner_r(skb, sk);
-                err = skb->len;
-                skb_queue_tail(&sk->sk_receive_queue, skb);
-                if (!sock_flag(sk, SOCK_DEAD))
-                        sk->sk_data_ready(sk, err);
-                return 0;
+                queue = &sk->sk_receive_queue;
+                goto queue;
 
         case PNS_PEP_STATUS_IND:
                 pipe_rcv_status(sk, skb);
@@ -412,12 +411,24 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
 out:
         kfree_skb(skb);
         return err;
+
+queue:
+        skb->dev = NULL;
+        skb_set_owner_r(skb, sk);
+        err = skb->len;
+        skb_queue_tail(queue, skb);
+        if (!sock_flag(sk, SOCK_DEAD))
+                sk->sk_data_ready(sk, err);
+        return 0;
 }
 
 /* Destroy connected sock. */
 static void pipe_destruct(struct sock *sk)
 {
+        struct pep_sock *pn = pep_sk(sk);
+
         skb_queue_purge(&sk->sk_receive_queue);
+        skb_queue_purge(&pn->ctrlreq_queue);
 }
 
 static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
@@ -490,6 +501,7 @@ static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb)
         pn_skb_get_dst_sockaddr(skb, &dst);
         newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
         newpn->pn_sk.resource = pn->pn_sk.resource;
+        skb_queue_head_init(&newpn->ctrlreq_queue);
         newpn->pipe_handle = pipe_handle;
         newpn->peer_type = peer_type;
         newpn->rx_credits = newpn->tx_credits = 0;
@@ -581,7 +593,7 @@ static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
                 break;
 
         case PNS_PEP_CTRL_REQ:
-                pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE);
+                pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
                 break;
 
         case PNS_PEP_RESET_REQ:
@@ -684,6 +696,7 @@ out:
 
 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
+        struct pep_sock *pn = pep_sk(sk);
         int answ;
 
         switch (cmd) {
@@ -692,7 +705,10 @@ static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
                         return -EINVAL;
 
                 lock_sock(sk);
-                if (!skb_queue_empty(&sk->sk_receive_queue))
+                if (sock_flag(sk, SOCK_URGINLINE)
+                 && !skb_queue_empty(&pn->ctrlreq_queue))
+                        answ = skb_peek(&pn->ctrlreq_queue)->len;
+                else if (!skb_queue_empty(&sk->sk_receive_queue))
                         answ = skb_peek(&sk->sk_receive_queue)->len;
                 else
                         answ = 0;
@@ -709,6 +725,7 @@ static int pep_init(struct sock *sk)
 
         INIT_HLIST_HEAD(&pn->ackq);
         INIT_HLIST_HEAD(&pn->hlist);
+        skb_queue_head_init(&pn->ctrlreq_queue);
         pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
         return 0;
 }
@@ -810,11 +827,24 @@ static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
         struct sk_buff *skb;
         int err;
 
-        if (unlikely(flags & MSG_OOB))
-                return -EOPNOTSUPP;
         if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
                 return -ENOTCONN;
 
+        if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
+                /* Dequeue and acknowledge control request */
+                struct pep_sock *pn = pep_sk(sk);
+
+                skb = skb_dequeue(&pn->ctrlreq_queue);
+                if (skb) {
+                        pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
+                                                GFP_KERNEL);
+                        msg->msg_flags |= MSG_OOB;
+                        goto copy;
+                }
+                if (flags & MSG_OOB)
+                        return -EINVAL;
+        }
+
         skb = skb_recv_datagram(sk, flags, noblock, &err);
         lock_sock(sk);
         if (skb == NULL) {
@@ -827,9 +857,8 @@ static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
         if (sk->sk_state == TCP_ESTABLISHED)
                 pipe_grant_credits(sk);
         release_sock(sk);
-
+copy:
         msg->msg_flags |= MSG_EOR;
-
         if (skb->len > len)
                 msg->msg_flags |= MSG_TRUNC;
         else
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index cea1136cbe46..a9c3d1f2e9db 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -220,7 +220,9 @@ static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 
         if (!skb_queue_empty(&sk->sk_receive_queue))
                 mask |= POLLIN | POLLRDNORM;
-        else if (sk->sk_state == TCP_CLOSE_WAIT)
+        if (!skb_queue_empty(&pn->ctrlreq_queue))
+                mask |= POLLPRI;
+        if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
                 return POLLHUP;
 
         if (sk->sk_state == TCP_ESTABLISHED && pn->tx_credits)