tipc: use generic SKB list APIs to manage TIPC outgoing packet chains

Use standard SKB list APIs associated with struct sk_buff_head to
manage socket outgoing packet chain and name table outgoing packet
chain, having relevant code simpler and more readable.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 61 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 341fbd1b5f74..9658d9b63876 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -244,12 +244,12 @@ static void tsk_advance_rx_queue(struct sock *sk)
  */
 static void tsk_rej_rx_queue(struct sock *sk)
 {
-        struct sk_buff *buf;
+        struct sk_buff *skb;
         u32 dnode;
 
-        while ((buf = __skb_dequeue(&sk->sk_receive_queue))) {
-                if (tipc_msg_reverse(buf, &dnode, TIPC_ERR_NO_PORT))
-                        tipc_link_xmit(buf, dnode, 0);
+        while ((skb = __skb_dequeue(&sk->sk_receive_queue))) {
+                if (tipc_msg_reverse(skb, &dnode, TIPC_ERR_NO_PORT))
+                        tipc_link_xmit_skb(skb, dnode, 0);
         }
 }
 
@@ -462,7 +462,7 @@ static int tipc_release(struct socket *sock)
 {
         struct sock *sk = sock->sk;
         struct tipc_sock *tsk;
-        struct sk_buff *buf;
+        struct sk_buff *skb;
         u32 dnode;
 
         /*
@@ -481,11 +481,11 @@ static int tipc_release(struct socket *sock)
          */
         dnode = tsk_peer_node(tsk);
         while (sock->state != SS_DISCONNECTING) {
-                buf = __skb_dequeue(&sk->sk_receive_queue);
-                if (buf == NULL)
+                skb = __skb_dequeue(&sk->sk_receive_queue);
+                if (skb == NULL)
                         break;
-                if (TIPC_SKB_CB(buf)->handle != NULL)
-                        kfree_skb(buf);
+                if (TIPC_SKB_CB(skb)->handle != NULL)
+                        kfree_skb(skb);
                 else {
                         if ((sock->state == SS_CONNECTING) ||
                             (sock->state == SS_CONNECTED)) {
@@ -493,8 +493,8 @@ static int tipc_release(struct socket *sock)
                                 tsk->connected = 0;
                                 tipc_node_remove_conn(dnode, tsk->ref);
                         }
-                        if (tipc_msg_reverse(buf, &dnode, TIPC_ERR_NO_PORT))
-                                tipc_link_xmit(buf, dnode, 0);
+                        if (tipc_msg_reverse(skb, &dnode, TIPC_ERR_NO_PORT))
+                                tipc_link_xmit_skb(skb, dnode, 0);
                 }
         }
 
@@ -502,12 +502,12 @@ static int tipc_release(struct socket *sock)
         tipc_sk_ref_discard(tsk->ref);
         k_cancel_timer(&tsk->timer);
         if (tsk->connected) {
-                buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
+                skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
                                       SHORT_H_SIZE, 0, dnode, tipc_own_addr,
                                       tsk_peer_port(tsk),
                                       tsk->ref, TIPC_ERR_NO_PORT);
-                if (buf)
-                        tipc_link_xmit(buf, dnode, tsk->ref);
+                if (skb)
+                        tipc_link_xmit_skb(skb, dnode, tsk->ref);
                 tipc_node_remove_conn(dnode, tsk->ref);
         }
         k_term_timer(&tsk->timer);
@@ -712,7 +712,7 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 {
         struct sock *sk = sock->sk;
         struct tipc_msg *mhdr = &tipc_sk(sk)->phdr;
-        struct sk_buff *buf;
+        struct sk_buff_head head;
         uint mtu;
         int rc;
 
@@ -727,12 +727,13 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 
 new_mtu:
         mtu = tipc_bclink_get_mtu();
-        rc = tipc_msg_build(mhdr, msg, 0, dsz, mtu, &buf);
+        __skb_queue_head_init(&head);
+        rc = tipc_msg_build(mhdr, msg, 0, dsz, mtu, &head);
         if (unlikely(rc < 0))
                 return rc;
 
         do {
-                rc = tipc_bclink_xmit(buf);
+                rc = tipc_bclink_xmit(&head);
                 if (likely(rc >= 0)) {
                         rc = dsz;
                         break;
@@ -744,7 +745,7 @@ new_mtu:
                 tipc_sk(sk)->link_cong = 1;
                 rc = tipc_wait_for_sndmsg(sock, &timeo);
                 if (rc)
-                        kfree_skb_list(buf);
+                        __skb_queue_purge(&head);
         } while (!rc);
         return rc;
 }
@@ -906,7 +907,8 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock,
         struct tipc_sock *tsk = tipc_sk(sk);
         struct tipc_msg *mhdr = &tsk->phdr;
         u32 dnode, dport;
-        struct sk_buff *buf;
+        struct sk_buff_head head;
+        struct sk_buff *skb;
         struct tipc_name_seq *seq = &dest->addr.nameseq;
         u32 mtu;
         long timeo;
@@ -981,13 +983,15 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock,
 
 new_mtu:
         mtu = tipc_node_get_mtu(dnode, tsk->ref);
-        rc = tipc_msg_build(mhdr, m, 0, dsz, mtu, &buf);
+        __skb_queue_head_init(&head);
+        rc = tipc_msg_build(mhdr, m, 0, dsz, mtu, &head);
         if (rc < 0)
                 goto exit;
 
         do {
-                TIPC_SKB_CB(buf)->wakeup_pending = tsk->link_cong;
-                rc = tipc_link_xmit(buf, dnode, tsk->ref);
+                skb = skb_peek(&head);
+                TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong;
+                rc = tipc_link_xmit(&head, dnode, tsk->ref);
                 if (likely(rc >= 0)) {
                         if (sock->state != SS_READY)
                                 sock->state = SS_CONNECTING;
@@ -1001,7 +1005,7 @@ new_mtu:
                 tsk->link_cong = 1;
                 rc = tipc_wait_for_sndmsg(sock, &timeo);
                 if (rc)
-                        kfree_skb_list(buf);
+                        __skb_queue_purge(&head);
         } while (!rc);
 exit:
         if (iocb)
@@ -1058,7 +1062,7 @@ static int tipc_send_stream(struct kiocb *iocb, struct socket *sock,
         struct sock *sk = sock->sk;
         struct tipc_sock *tsk = tipc_sk(sk);
         struct tipc_msg *mhdr = &tsk->phdr;
-        struct sk_buff *buf;
+        struct sk_buff_head head;
         DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
         u32 ref = tsk->ref;
         int rc = -EINVAL;
@@ -1093,12 +1097,13 @@ static int tipc_send_stream(struct kiocb *iocb, struct socket *sock,
 next:
         mtu = tsk->max_pkt;
         send = min_t(uint, dsz - sent, TIPC_MAX_USER_MSG_SIZE);
-        rc = tipc_msg_build(mhdr, m, sent, send, mtu, &buf);
+        __skb_queue_head_init(&head);
+        rc = tipc_msg_build(mhdr, m, sent, send, mtu, &head);
         if (unlikely(rc < 0))
                 goto exit;
         do {
                 if (likely(!tsk_conn_cong(tsk))) {
-                        rc = tipc_link_xmit(buf, dnode, ref);
+                        rc = tipc_link_xmit(&head, dnode, ref);
                         if (likely(!rc)) {
                                 tsk->sent_unacked++;
                                 sent += send;
@@ -1116,7 +1121,7 @@ next:
                 }
                 rc = tipc_wait_for_sndpkt(sock, &timeo);
                 if (rc)
-                        kfree_skb_list(buf);
+                        __skb_queue_purge(&head);
         } while (!rc);
 exit:
         if (iocb)
@@ -1261,20 +1266,20 @@ static int tipc_sk_anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
 
 static void tipc_sk_send_ack(struct tipc_sock *tsk, uint ack)
 {
-        struct sk_buff *buf = NULL;
+        struct sk_buff *skb = NULL;
         struct tipc_msg *msg;
         u32 peer_port = tsk_peer_port(tsk);
         u32 dnode = tsk_peer_node(tsk);
 
         if (!tsk->connected)
                 return;
-        buf = tipc_msg_create(CONN_MANAGER, CONN_ACK, INT_H_SIZE, 0, dnode,
+        skb = tipc_msg_create(CONN_MANAGER, CONN_ACK, INT_H_SIZE, 0, dnode,
                               tipc_own_addr, peer_port, tsk->ref, TIPC_OK);
-        if (!buf)
+        if (!skb)
                 return;
-        msg = buf_msg(buf);
+        msg = buf_msg(skb);
         msg_set_msgcnt(msg, ack);
-        tipc_link_xmit(buf, dnode, msg_link_selector(msg));
+        tipc_link_xmit_skb(skb, dnode, msg_link_selector(msg));
 }
 
 static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
@@ -1729,20 +1734,20 @@ static int filter_rcv(struct sock *sk, struct sk_buff *buf)
 /**
  * tipc_backlog_rcv - handle incoming message from backlog queue
  * @sk: socket
- * @buf: message
+ * @skb: message
  *
  * Caller must hold socket lock, but not port lock.
  *
  * Returns 0
  */
-static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *buf)
+static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
         int rc;
         u32 onode;
         struct tipc_sock *tsk = tipc_sk(sk);
-        uint truesize = buf->truesize;
+        uint truesize = skb->truesize;
 
-        rc = filter_rcv(sk, buf);
+        rc = filter_rcv(sk, skb);
 
         if (likely(!rc)) {
                 if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT)
@@ -1750,25 +1755,25 @@ static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *buf)
                 return 0;
         }
 
-        if ((rc < 0) && !tipc_msg_reverse(buf, &onode, -rc))
+        if ((rc < 0) && !tipc_msg_reverse(skb, &onode, -rc))
                 return 0;
 
-        tipc_link_xmit(buf, onode, 0);
+        tipc_link_xmit_skb(skb, onode, 0);
 
         return 0;
 }
 
 /**
  * tipc_sk_rcv - handle incoming message
- * @buf: buffer containing arriving message
+ * @skb: buffer containing arriving message
  * Consumes buffer
  * Returns 0 if success, or errno: -EHOSTUNREACH
  */
-int tipc_sk_rcv(struct sk_buff *buf)
+int tipc_sk_rcv(struct sk_buff *skb)
 {
         struct tipc_sock *tsk;
         struct sock *sk;
-        u32 dport = msg_destport(buf_msg(buf));
+        u32 dport = msg_destport(buf_msg(skb));
         int rc = TIPC_OK;
         uint limit;
         u32 dnode;
@@ -1776,7 +1781,7 @@ int tipc_sk_rcv(struct sk_buff *buf)
         /* Validate destination and message */
         tsk = tipc_sk_get(dport);
         if (unlikely(!tsk)) {
-                rc = tipc_msg_eval(buf, &dnode);
+                rc = tipc_msg_eval(skb, &dnode);
                 goto exit;
         }
         sk = &tsk->sk;
@@ -1785,12 +1790,12 @@ int tipc_sk_rcv(struct sk_buff *buf)
         spin_lock_bh(&sk->sk_lock.slock);
 
         if (!sock_owned_by_user(sk)) {
-                rc = filter_rcv(sk, buf);
+                rc = filter_rcv(sk, skb);
         } else {
                 if (sk->sk_backlog.len == 0)
                         atomic_set(&tsk->dupl_rcvcnt, 0);
-                limit = rcvbuf_limit(sk, buf) + atomic_read(&tsk->dupl_rcvcnt);
-                if (sk_add_backlog(sk, buf, limit))
+                limit = rcvbuf_limit(sk, skb) + atomic_read(&tsk->dupl_rcvcnt);
+                if (sk_add_backlog(sk, skb, limit))
                         rc = -TIPC_ERR_OVERLOAD;
         }
         spin_unlock_bh(&sk->sk_lock.slock);
@@ -1798,10 +1803,10 @@ int tipc_sk_rcv(struct sk_buff *buf)
         if (likely(!rc))
                 return 0;
 exit:
-        if ((rc < 0) && !tipc_msg_reverse(buf, &dnode, -rc))
+        if ((rc < 0) && !tipc_msg_reverse(skb, &dnode, -rc))
                 return -EHOSTUNREACH;
 
-        tipc_link_xmit(buf, dnode, 0);
+        tipc_link_xmit_skb(skb, dnode, 0);
         return (rc < 0) ? -EHOSTUNREACH : 0;
 }
 
@@ -2059,7 +2064,7 @@ static int tipc_shutdown(struct socket *sock, int how)
 {
         struct sock *sk = sock->sk;
         struct tipc_sock *tsk = tipc_sk(sk);
-        struct sk_buff *buf;
+        struct sk_buff *skb;
         u32 dnode;
         int res;
 
@@ -2074,23 +2079,23 @@ static int tipc_shutdown(struct socket *sock, int how)
 
 restart:
                 /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
-                buf = __skb_dequeue(&sk->sk_receive_queue);
-                if (buf) {
-                        if (TIPC_SKB_CB(buf)->handle != NULL) {
-                                kfree_skb(buf);
+                skb = __skb_dequeue(&sk->sk_receive_queue);
+                if (skb) {
+                        if (TIPC_SKB_CB(skb)->handle != NULL) {
+                                kfree_skb(skb);
                                 goto restart;
                         }
-                        if (tipc_msg_reverse(buf, &dnode, TIPC_CONN_SHUTDOWN))
-                                tipc_link_xmit(buf, dnode, tsk->ref);
+                        if (tipc_msg_reverse(skb, &dnode, TIPC_CONN_SHUTDOWN))
+                                tipc_link_xmit_skb(skb, dnode, tsk->ref);
                         tipc_node_remove_conn(dnode, tsk->ref);
                 } else {
                         dnode = tsk_peer_node(tsk);
-                        buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
+                        skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
                                               TIPC_CONN_MSG, SHORT_H_SIZE,
                                               0, dnode, tipc_own_addr,
                                               tsk_peer_port(tsk),
                                               tsk->ref, TIPC_CONN_SHUTDOWN);
-                        tipc_link_xmit(buf, dnode, tsk->ref);
+                        tipc_link_xmit_skb(skb, dnode, tsk->ref);
                 }
                 tsk->connected = 0;
                 sock->state = SS_DISCONNECTING;
@@ -2119,7 +2124,7 @@ static void tipc_sk_timeout(unsigned long ref)
 {
         struct tipc_sock *tsk;
         struct sock *sk;
-        struct sk_buff *buf = NULL;
+        struct sk_buff *skb = NULL;
         u32 peer_port, peer_node;
 
         tsk = tipc_sk_get(ref);
@@ -2137,20 +2142,20 @@ static void tipc_sk_timeout(unsigned long ref)
 
         if (tsk->probing_state == TIPC_CONN_PROBING) {
                 /* Previous probe not answered -> self abort */
-                buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
+                skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
                                       SHORT_H_SIZE, 0, tipc_own_addr,
                                       peer_node, ref, peer_port,
                                       TIPC_ERR_NO_PORT);
         } else {
-                buf = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE,
+                skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE,
                                       0, peer_node, tipc_own_addr,
                                       peer_port, ref, TIPC_OK);
                 tsk->probing_state = TIPC_CONN_PROBING;
                 k_start_timer(&tsk->timer, tsk->probing_interval);
         }
         bh_unlock_sock(sk);
-        if (buf)
-                tipc_link_xmit(buf, peer_node, ref);
+        if (skb)
+                tipc_link_xmit_skb(skb, peer_node, ref);
 exit:
         tipc_sk_put(tsk);
 }