net: qrtr: Clean up control packet handling

As the message header generation is deferred the internal functions for
generating control packets can be simplified.

This patch modifies qrtr_alloc_ctrl_packet() to, in addition to the
sk_buff, return a reference to a struct qrtr_ctrl_pkt, which clarifies
and simplifies the helpers to the point that these functions can be
folded back into the callers.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 29 insertions, 64 deletions

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index 82dc83789310..a84edba7b1ef 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c
@@ -255,9 +255,18 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
 }
 EXPORT_SYMBOL_GPL(qrtr_endpoint_post);
 
-static struct sk_buff *qrtr_alloc_ctrl_packet(u32 type, size_t pkt_len,
-                                              u32 src_node, u32 dst_node)
+/**
+ * qrtr_alloc_ctrl_packet() - allocate control packet skb
+ * @pkt: reference to qrtr_ctrl_pkt pointer
+ *
+ * Returns newly allocated sk_buff, or NULL on failure
+ *
+ * This function allocates a sk_buff large enough to carry a qrtr_ctrl_pkt and
+ * on success returns a reference to the control packet in @pkt.
+ */
+static struct sk_buff *qrtr_alloc_ctrl_packet(struct qrtr_ctrl_pkt **pkt)
 {
+        const int pkt_len = sizeof(struct qrtr_ctrl_pkt);
         struct sk_buff *skb;
 
         skb = alloc_skb(QRTR_HDR_SIZE + pkt_len, GFP_KERNEL);
@@ -265,64 +274,7 @@ static struct sk_buff *qrtr_alloc_ctrl_packet(u32 type, size_t pkt_len,
                 return NULL;
 
         skb_reserve(skb, QRTR_HDR_SIZE);
-
-        return skb;
-}
-
-/* Allocate and construct a resume-tx packet. */
-static struct sk_buff *qrtr_alloc_resume_tx(u32 src_node,
-                                            u32 dst_node, u32 port)
-{
-        const int pkt_len = 20;
-        struct sk_buff *skb;
-        __le32 *buf;
-
-        skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_RESUME_TX, pkt_len,
-                                     src_node, dst_node);
-        if (!skb)
-                return NULL;
-
-        buf = skb_put_zero(skb, pkt_len);
-        buf[0] = cpu_to_le32(QRTR_TYPE_RESUME_TX);
-        buf[1] = cpu_to_le32(src_node);
-        buf[2] = cpu_to_le32(port);
-
-        return skb;
-}
-
-/* Allocate and construct a BYE message to signal remote termination */
-static struct sk_buff *qrtr_alloc_local_bye(u32 src_node)
-{
-        const int pkt_len = 20;
-        struct sk_buff *skb;
-        __le32 *buf;
-
-        skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_BYE, pkt_len,
-                                     src_node, qrtr_local_nid);
-        if (!skb)
-                return NULL;
-
-        buf = skb_put_zero(skb, pkt_len);
-        buf[0] = cpu_to_le32(QRTR_TYPE_BYE);
-
-        return skb;
-}
-
-static struct sk_buff *qrtr_alloc_del_client(struct sockaddr_qrtr *sq)
-{
-        const int pkt_len = 20;
-        struct sk_buff *skb;
-        __le32 *buf;
-
-        skb = qrtr_alloc_ctrl_packet(QRTR_TYPE_DEL_CLIENT, pkt_len,
-                                     sq->sq_node, QRTR_NODE_BCAST);
-        if (!skb)
-                return NULL;
-
-        buf = skb_put_zero(skb, pkt_len);
-        buf[0] = cpu_to_le32(QRTR_TYPE_DEL_CLIENT);
-        buf[1] = cpu_to_le32(sq->sq_node);
-        buf[2] = cpu_to_le32(sq->sq_port);
+        *pkt = skb_put_zero(skb, pkt_len);
 
         return skb;
 }
@@ -337,6 +289,7 @@ static void qrtr_port_put(struct qrtr_sock *ipc);
 static void qrtr_node_rx_work(struct work_struct *work)
 {
         struct qrtr_node *node = container_of(work, struct qrtr_node, work);
+        struct qrtr_ctrl_pkt *pkt;
         struct sockaddr_qrtr dst;
         struct sockaddr_qrtr src;
         struct sk_buff *skb;
@@ -372,10 +325,14 @@ static void qrtr_node_rx_work(struct work_struct *work)
                 }
 
                 if (confirm) {
-                        skb = qrtr_alloc_resume_tx(dst_node, node->nid, dst_port);
+                        skb = qrtr_alloc_ctrl_packet(&pkt);
                         if (!skb)
                                 break;
 
+                        pkt->cmd = cpu_to_le32(QRTR_TYPE_RESUME_TX);
+                        pkt->client.node = cpu_to_le32(dst.sq_node);
+                        pkt->client.port = cpu_to_le32(dst.sq_port);
+
                         if (qrtr_node_enqueue(node, skb, QRTR_TYPE_RESUME_TX,
                                               &dst, &src))
                                 break;
@@ -429,6 +386,7 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
         struct qrtr_node *node = ep->node;
         struct sockaddr_qrtr src = {AF_QIPCRTR, node->nid, QRTR_PORT_CTRL};
         struct sockaddr_qrtr dst = {AF_QIPCRTR, qrtr_local_nid, QRTR_PORT_CTRL};
+        struct qrtr_ctrl_pkt *pkt;
         struct sk_buff *skb;
 
         mutex_lock(&node->ep_lock);
@@ -436,9 +394,11 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep)
         mutex_unlock(&node->ep_lock);
 
         /* Notify the local controller about the event */
-        skb = qrtr_alloc_local_bye(node->nid);
-        if (skb)
+        skb = qrtr_alloc_ctrl_packet(&pkt);
+        if (skb) {
+                pkt->cmd = cpu_to_le32(QRTR_TYPE_BYE);
                 qrtr_local_enqueue(NULL, skb, QRTR_TYPE_BYE, &src, &dst);
+        }
 
         qrtr_node_release(node);
         ep->node = NULL;
@@ -474,6 +434,7 @@ static void qrtr_port_put(struct qrtr_sock *ipc)
 /* Remove port assignment. */
 static void qrtr_port_remove(struct qrtr_sock *ipc)
 {
+        struct qrtr_ctrl_pkt *pkt;
         struct sk_buff *skb;
         int port = ipc->us.sq_port;
         struct sockaddr_qrtr to;
@@ -482,8 +443,12 @@ static void qrtr_port_remove(struct qrtr_sock *ipc)
         to.sq_node = QRTR_NODE_BCAST;
         to.sq_port = QRTR_PORT_CTRL;
 
-        skb = qrtr_alloc_del_client(&ipc->us);
+        skb = qrtr_alloc_ctrl_packet(&pkt);
         if (skb) {
+                pkt->cmd = cpu_to_le32(QRTR_TYPE_DEL_CLIENT);
+                pkt->client.node = cpu_to_le32(ipc->us.sq_node);
+                pkt->client.port = cpu_to_le32(ipc->us.sq_port);
+
                 skb_set_owner_w(skb, &ipc->sk);
                 qrtr_bcast_enqueue(NULL, skb, QRTR_TYPE_DEL_CLIENT, &ipc->us,
                                    &to);