Phonet: factor common code to send control messages
Rémi Denis-Courmont [Tue, 8 Mar 2011 22:44:09 +0000 (22:44 +0000)]
With the addition of the pipe controller, there is now quite a bit
of repetitive code for small signaling messages. Lets factor it.

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

net/phonet/pep.c

index 40952c7..610794a 100644 (file)
@@ -77,24 +77,34 @@ static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
        return data;
 }
 
-static int pep_reply(struct sock *sk, struct sk_buff *oskb,
-                       u8 code, const void *data, int len, gfp_t priority)
+static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
+                                       int len, gfp_t priority)
+{
+       struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
+       if (!skb)
+               return NULL;
+       skb_set_owner_w(skb, sk);
+
+       skb_reserve(skb, MAX_PNPIPE_HEADER);
+       __skb_put(skb, len);
+       skb_copy_to_linear_data(skb, payload, len);
+       __skb_push(skb, sizeof(struct pnpipehdr));
+       skb_reset_transport_header(skb);
+       return skb;
+}
+
+static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
+                       const void *data, int len, gfp_t priority)
 {
        const struct pnpipehdr *oph = pnp_hdr(oskb);
        struct pnpipehdr *ph;
        struct sk_buff *skb;
        struct sockaddr_pn peer;
 
-       skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
+       skb = pep_alloc_skb(sk, data, len, priority);
        if (!skb)
                return -ENOMEM;
-       skb_set_owner_w(skb, sk);
 
-       skb_reserve(skb, MAX_PNPIPE_HEADER);
-       __skb_put(skb, len);
-       skb_copy_to_linear_data(skb, data, len);
-       __skb_push(skb, sizeof(*ph));
-       skb_reset_transport_header(skb);
        ph = pnp_hdr(skb);
        ph->utid = oph->utid;
        ph->message_id = oph->message_id + 1; /* REQ -> RESP */
@@ -105,135 +115,69 @@ static int pep_reply(struct sock *sk, struct sk_buff *oskb,
        return pn_skb_send(sk, skb, &peer);
 }
 
-#define PAD 0x00
-
-#ifdef CONFIG_PHONET_PIPECTRLR
-static int pipe_handler_send_req(struct sock *sk, u8 msg_id, gfp_t priority)
+static int pep_indicate(struct sock *sk, u8 id, u8 code,
+                       const void *data, int len, gfp_t priority)
 {
-       int len;
+       struct pep_sock *pn = pep_sk(sk);
        struct pnpipehdr *ph;
        struct sk_buff *skb;
-       struct pep_sock *pn = pep_sk(sk);
-
-       static const u8 data[4] = {
-               PAD, PAD, PAD, PAD,
-       };
 
-       switch (msg_id) {
-       case PNS_PEP_CONNECT_REQ:
-               len = sizeof(data);
-               break;
-
-       case PNS_PEP_DISCONNECT_REQ:
-       case PNS_PEP_ENABLE_REQ:
-       case PNS_PEP_DISABLE_REQ:
-               len = 0;
-               break;
-
-       default:
-               return -EINVAL;
-       }
-
-       skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
+       skb = pep_alloc_skb(sk, data, len, priority);
        if (!skb)
                return -ENOMEM;
-       skb_set_owner_w(skb, sk);
 
-       skb_reserve(skb, MAX_PNPIPE_HEADER);
-       if (len) {
-               __skb_put(skb, len);
-               skb_copy_to_linear_data(skb, data, len);
-       }
-       __skb_push(skb, sizeof(*ph));
-       skb_reset_transport_header(skb);
        ph = pnp_hdr(skb);
-       ph->utid = msg_id; /* whatever */
-       ph->message_id = msg_id;
+       ph->utid = 0;
+       ph->message_id = id;
        ph->pipe_handle = pn->pipe_handle;
-       ph->error_code = PN_PIPE_NO_ERROR;
-
+       ph->data[0] = code;
        return pn_skb_send(sk, skb, NULL);
 }
 
-static int pipe_handler_send_created_ind(struct sock *sk, u8 msg_id)
+#define PAD 0x00
+
+#ifdef CONFIG_PHONET_PIPECTRLR
+static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
+                               const void *data, int len)
 {
-       int err_code;
+       struct pep_sock *pn = pep_sk(sk);
        struct pnpipehdr *ph;
        struct sk_buff *skb;
 
-       struct pep_sock *pn = pep_sk(sk);
-       static u8 data[4] = {
-               0x03, 0x04,
-       };
-       data[2] = pn->tx_fc;
-       data[3] = pn->rx_fc;
-
-       /*
-        * actually, below is number of sub-blocks and not error code.
-        * Pipe_created_ind message format does not have any
-        * error code field. However, the Phonet stack will always send
-        * an error code as part of pnpipehdr. So, use that err_code to
-        * specify the number of sub-blocks.
-        */
-       err_code = 0x01;
-
-       skb = alloc_skb(MAX_PNPIPE_HEADER + sizeof(data), GFP_ATOMIC);
+       skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
-       skb_set_owner_w(skb, sk);
 
-       skb_reserve(skb, MAX_PNPIPE_HEADER);
-       __skb_put(skb, sizeof(data));
-       skb_copy_to_linear_data(skb, data, sizeof(data));
-       __skb_push(skb, sizeof(*ph));
-       skb_reset_transport_header(skb);
        ph = pnp_hdr(skb);
-       ph->utid = 0;
-       ph->message_id = msg_id;
+       ph->utid = id; /* whatever */
+       ph->message_id = id;
        ph->pipe_handle = pn->pipe_handle;
-       ph->error_code = err_code;
-
+       ph->data[0] = code;
        return pn_skb_send(sk, skb, NULL);
 }
 
-static int pipe_handler_send_ind(struct sock *sk, u8 msg_id)
+static int pipe_handler_send_created_ind(struct sock *sk)
 {
-       int err_code;
-       struct pnpipehdr *ph;
-       struct sk_buff *skb;
        struct pep_sock *pn = pep_sk(sk);
+       u8 data[4] = {
+               PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
+               pn->tx_fc, pn->rx_fc,
+       };
 
-       /*
-        * actually, below is a filler.
-        * Pipe_enabled/disabled_ind message format does not have any
-        * error code field. However, the Phonet stack will always send
-        * an error code as part of pnpipehdr. So, use that err_code to
-        * specify the filler value.
-        */
-       err_code = 0x0;
-
-       skb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
-       if (!skb)
-               return -ENOMEM;
-       skb_set_owner_w(skb, sk);
-
-       skb_reserve(skb, MAX_PNPIPE_HEADER);
-       __skb_push(skb, sizeof(*ph));
-       skb_reset_transport_header(skb);
-       ph = pnp_hdr(skb);
-       ph->utid = 0;
-       ph->message_id = msg_id;
-       ph->pipe_handle = pn->pipe_handle;
-       ph->error_code = err_code;
+       return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
+                               data, 4, GFP_ATOMIC);
+}
 
-       return pn_skb_send(sk, skb, NULL);
+static int pipe_handler_send_ind(struct sock *sk, u8 id)
+{
+       return pep_indicate(sk, id, PAD, NULL, 0, GFP_ATOMIC);
 }
 
 static int pipe_handler_enable_pipe(struct sock *sk, int enable)
 {
        u8 id = enable ? PNS_PEP_ENABLE_REQ : PNS_PEP_DISABLE_REQ;
 
-       return pipe_handler_send_req(sk, id, GFP_KERNEL);
+       return pipe_handler_request(sk, id, PAD, NULL, 0);
 }
 #endif
 
@@ -274,23 +218,21 @@ static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
        struct sk_buff *skb;
        struct pnpipehdr *ph;
        struct sockaddr_pn dst;
+       u8 data[4] = {
+               oph->data[0], /* PEP type */
+               code, /* error code, at an unusual offset */
+               PAD, PAD,
+       };
 
-       skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
+       skb = pep_alloc_skb(sk, data, 4, priority);
        if (!skb)
                return -ENOMEM;
-       skb_set_owner_w(skb, sk);
-
-       skb_reserve(skb, MAX_PHONET_HEADER);
-       ph = (struct pnpipehdr *)skb_put(skb, sizeof(*ph) + 4);
 
+       ph = pnp_hdr(skb);
        ph->utid = oph->utid;
        ph->message_id = PNS_PEP_CTRL_RESP;
        ph->pipe_handle = oph->pipe_handle;
        ph->data[0] = oph->data[1]; /* CTRL id */
-       ph->data[1] = oph->data[0]; /* PEP type */
-       ph->data[2] = code; /* error code, at an usual offset */
-       ph->data[3] = PAD;
-       ph->data[4] = PAD;
 
        pn_skb_get_src_sockaddr(oskb, &dst);
        return pn_skb_send(sk, skb, &dst);
@@ -298,34 +240,15 @@ static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
 
 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
 {
-       struct pep_sock *pn = pep_sk(sk);
-       struct pnpipehdr *ph;
-       struct sk_buff *skb;
+       u8 data[4] = { type, PAD, PAD, status };
 
-       skb = alloc_skb(MAX_PNPIPE_HEADER + 4, priority);
-       if (!skb)
-               return -ENOMEM;
-       skb_set_owner_w(skb, sk);
-
-       skb_reserve(skb, MAX_PNPIPE_HEADER + 4);
-       __skb_push(skb, sizeof(*ph) + 4);
-       skb_reset_transport_header(skb);
-       ph = pnp_hdr(skb);
-       ph->utid = 0;
-       ph->message_id = PNS_PEP_STATUS_IND;
-       ph->pipe_handle = pn->pipe_handle;
-       ph->pep_type = PN_PEP_TYPE_COMMON;
-       ph->data[1] = type;
-       ph->data[2] = PAD;
-       ph->data[3] = PAD;
-       ph->data[4] = status;
-
-       return pn_skb_send(sk, skb, NULL);
+       return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
+                               data, 4, priority);
 }
 
 /* Send our RX flow control information to the sender.
  * Socket must be locked. */
-static void pipe_grant_credits(struct sock *sk)
+static void pipe_grant_credits(struct sock *sk, gfp_t priority)
 {
        struct pep_sock *pn = pep_sk(sk);
 
@@ -335,16 +258,16 @@ static void pipe_grant_credits(struct sock *sk)
        case PN_LEGACY_FLOW_CONTROL: /* TODO */
                break;
        case PN_ONE_CREDIT_FLOW_CONTROL:
-               pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
-                               PEP_IND_READY, GFP_ATOMIC);
-               pn->rx_credits = 1;
+               if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
+                                       PEP_IND_READY, priority) == 0)
+                       pn->rx_credits = 1;
                break;
        case PN_MULTI_CREDIT_FLOW_CONTROL:
                if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
                        break;
                if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
                                        CREDITS_MAX - pn->rx_credits,
-                                       GFP_ATOMIC) == 0)
+                                       priority) == 0)
                        pn->rx_credits = CREDITS_MAX;
                break;
        }
@@ -474,7 +397,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
                if (sk->sk_state == TCP_ESTABLISHED)
                        break; /* Nothing to do */
                sk->sk_state = TCP_ESTABLISHED;
-               pipe_grant_credits(sk);
+               pipe_grant_credits(sk, GFP_ATOMIC);
                break;
 #endif
 
@@ -561,7 +484,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
                if (sk->sk_state == TCP_ESTABLISHED)
                        break; /* Nothing to do */
                sk->sk_state = TCP_ESTABLISHED;
-               pipe_grant_credits(sk);
+               pipe_grant_credits(sk, GFP_ATOMIC);
                break;
 
        case PNS_PIPE_DISABLED_IND:
@@ -655,7 +578,7 @@ static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
        pn->rx_credits = 0;
        sk->sk_state_change(sk);
 
-       return pipe_handler_send_created_ind(sk, PNS_PIPE_CREATED_IND);
+       return pipe_handler_send_created_ind(sk);
 }
 #endif
 
@@ -853,19 +776,15 @@ static int pipe_do_remove(struct sock *sk)
        struct pnpipehdr *ph;
        struct sk_buff *skb;
 
-       skb = alloc_skb(MAX_PNPIPE_HEADER, GFP_KERNEL);
+       skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
 
-       skb_reserve(skb, MAX_PNPIPE_HEADER);
-       __skb_push(skb, sizeof(*ph));
-       skb_reset_transport_header(skb);
        ph = pnp_hdr(skb);
        ph->utid = 0;
        ph->message_id = PNS_PIPE_REMOVE_REQ;
        ph->pipe_handle = pn->pipe_handle;
        ph->data[0] = PAD;
-
        return pn_skb_send(sk, skb, NULL);
 }
 #endif
@@ -894,7 +813,7 @@ static void pep_sock_close(struct sock *sk, long timeout)
                pipe_do_remove(sk);
 #else
                /* send pep disconnect request */
-               pipe_handler_send_req(sk, PNS_PEP_DISCONNECT_REQ, GFP_KERNEL);
+               pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD, NULL, 0);
                sk->sk_state = TCP_CLOSE;
 #endif
        }
@@ -980,10 +899,12 @@ static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
 {
        struct pep_sock *pn = pep_sk(sk);
        const struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
+       u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
 
        pn->pn_sk.dobject = pn_sockaddr_get_object(spn);
        pn->pn_sk.resource = pn_sockaddr_get_resource(spn);
-       return pipe_handler_send_req(sk, PNS_PEP_CONNECT_REQ, GFP_KERNEL);
+       return pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
+                                       PN_PIPE_DISABLE, data, 4);
 }
 #endif
 
@@ -1280,7 +1201,7 @@ struct sk_buff *pep_read(struct sock *sk)
        struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
 
        if (sk->sk_state == TCP_ESTABLISHED)
-               pipe_grant_credits(sk);
+               pipe_grant_credits(sk, GFP_ATOMIC);
        return skb;
 }
 
@@ -1325,7 +1246,7 @@ static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
        }
 
        if (sk->sk_state == TCP_ESTABLISHED)
-               pipe_grant_credits(sk);
+               pipe_grant_credits(sk, GFP_KERNEL);
        release_sock(sk);
 copy:
        msg->msg_flags |= MSG_EOR;