tipc: clean up link creation

We simplify the link creation function tipc_link_create() and the way
the link struct it is connected to the node struct. In particular, we
remove the duplicate initialization of some fields which are anyway set
in tipc_link_reset().

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

4 files changed, 86 insertions, 121 deletions

diff --git a/net/tipc/core.h b/net/tipc/core.h
index f4ed67778c54..b96b41eabf12 100644
--- a/net/tipc/core.h
+++ b/net/tipc/core.h
@@ -109,6 +109,11 @@ struct tipc_net {
         atomic_t subscription_count;
 };
 
+static inline struct tipc_net *tipc_net(struct net *net)
+{
+        return net_generic(net, tipc_net_id);
+}
+
 static inline u16 mod(u16 x)
 {
         return x & 0xffffu;
diff --git a/net/tipc/link.c b/net/tipc/link.c
index d683fe9f68c8..f067e5425560 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -147,87 +147,71 @@ int tipc_link_is_active(struct tipc_link *l)
         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 }
 
+static u32 link_own_addr(struct tipc_link *l)
+{
+        return msg_prevnode(l->pmsg);
+}
+
 /**
  * tipc_link_create - create a new link
- * @n_ptr: pointer to associated node
- * @b_ptr: pointer to associated bearer
- * @media_addr: media address to use when sending messages over link
+ * @n: pointer to associated node
+ * @b: pointer to associated bearer
+ * @ownnode: identity of own node
+ * @peer: identity of peer node
+ * @maddr: media address to be used
+ * @inputq: queue to put messages ready for delivery
+ * @namedq: queue to put binding table update messages ready for delivery
+ * @link: return value, pointer to put the created link
  *
- * Returns pointer to link.
+ * Returns true if link was created, otherwise false
  */
-struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
-                                   struct tipc_bearer *b_ptr,
-                                   const struct tipc_media_addr *media_addr,
-                                   struct sk_buff_head *inputq,
-                                   struct sk_buff_head *namedq)
+bool tipc_link_create(struct tipc_node *n, struct tipc_bearer *b, u32 session,
+                      u32 ownnode, u32 peer, struct tipc_media_addr *maddr,
+                      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
+                      struct tipc_link **link)
 {
-        struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
-        struct tipc_link *l_ptr;
-        struct tipc_msg *msg;
+        struct tipc_link *l;
+        struct tipc_msg *hdr;
         char *if_name;
-        char addr_string[16];
-        u32 peer = n_ptr->addr;
 
-        if (n_ptr->link_cnt >= MAX_BEARERS) {
-                tipc_addr_string_fill(addr_string, n_ptr->addr);
-                pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
-                       n_ptr->link_cnt, addr_string, MAX_BEARERS);
-                return NULL;
-        }
+        l = kzalloc(sizeof(*l), GFP_ATOMIC);
+        if (!l)
+                return false;
+        *link = l;
 
-        if (n_ptr->links[b_ptr->identity].link) {
-                tipc_addr_string_fill(addr_string, n_ptr->addr);
-                pr_err("Attempt to establish second link on <%s> to %s\n",
-                       b_ptr->name, addr_string);
-                return NULL;
-        }
+        /* Note: peer i/f name is completed by reset/activate message */
+        if_name = strchr(b->name, ':') + 1;
+        sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
+                tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
+                if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 
-        l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
-        if (!l_ptr) {
-                pr_warn("Link creation failed, no memory\n");
-                return NULL;
-        }
-        l_ptr->addr = peer;
-        if_name = strchr(b_ptr->name, ':') + 1;
-        sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
-                tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
-                tipc_node(tn->own_addr),
-                if_name,
-                tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
-                /* note: peer i/f name is updated by reset/activate message */
-        memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
-        l_ptr->owner = n_ptr;
-        l_ptr->peer_session = WILDCARD_SESSION;
-        l_ptr->bearer_id = b_ptr->identity;
-        l_ptr->tolerance = b_ptr->tolerance;
-        l_ptr->snd_nxt = 1;
-        l_ptr->rcv_nxt = 1;
-        l_ptr->state = LINK_RESET;
-
-        l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
-        msg = l_ptr->pmsg;
-        tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
-                      l_ptr->addr);
-        msg_set_size(msg, sizeof(l_ptr->proto_msg));
-        msg_set_session(msg, (tn->random & 0xffff));
-        msg_set_bearer_id(msg, b_ptr->identity);
-        strcpy((char *)msg_data(msg), if_name);
-        l_ptr->net_plane = b_ptr->net_plane;
-        l_ptr->advertised_mtu = b_ptr->mtu;
-        l_ptr->mtu = l_ptr->advertised_mtu;
-        l_ptr->priority = b_ptr->priority;
-        tipc_link_set_queue_limits(l_ptr, b_ptr->window);
-        l_ptr->snd_nxt = 1;
-        __skb_queue_head_init(&l_ptr->transmq);
-        __skb_queue_head_init(&l_ptr->backlogq);
-        __skb_queue_head_init(&l_ptr->deferdq);
-        skb_queue_head_init(&l_ptr->wakeupq);
-        l_ptr->inputq = inputq;
-        l_ptr->namedq = namedq;
-        skb_queue_head_init(l_ptr->inputq);
-        link_reset_statistics(l_ptr);
-        tipc_node_attach_link(n_ptr, l_ptr);
-        return l_ptr;
+        l->addr = peer;
+        l->media_addr = maddr;
+        l->owner = n;
+        l->peer_session = WILDCARD_SESSION;
+        l->bearer_id = b->identity;
+        l->tolerance = b->tolerance;
+        l->net_plane = b->net_plane;
+        l->advertised_mtu = b->mtu;
+        l->mtu = b->mtu;
+        l->priority = b->priority;
+        tipc_link_set_queue_limits(l, b->window);
+        l->inputq = inputq;
+        l->namedq = namedq;
+        l->state = LINK_RESETTING;
+        l->pmsg = (struct tipc_msg *)&l->proto_msg;
+        hdr = l->pmsg;
+        tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
+        msg_set_size(hdr, sizeof(l->proto_msg));
+        msg_set_session(hdr, session);
+        msg_set_bearer_id(hdr, l->bearer_id);
+        strcpy((char *)msg_data(hdr), if_name);
+        __skb_queue_head_init(&l->transmq);
+        __skb_queue_head_init(&l->backlogq);
+        __skb_queue_head_init(&l->deferdq);
+        skb_queue_head_init(&l->wakeupq);
+        skb_queue_head_init(l->inputq);
+        return true;
 }
 
 /* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
@@ -643,7 +627,7 @@ int __tipc_link_xmit(struct net *net, struct tipc_link *link,
         u16 ack = mod(link->rcv_nxt - 1);
         u16 seqno = link->snd_nxt;
         u16 bc_last_in = link->owner->bclink.last_in;
-        struct tipc_media_addr *addr = &link->media_addr;
+        struct tipc_media_addr *addr = link->media_addr;
         struct sk_buff_head *transmq = &link->transmq;
         struct sk_buff_head *backlogq = &link->backlogq;
         struct sk_buff *skb, *bskb;
@@ -809,7 +793,7 @@ void tipc_link_push_packets(struct tipc_link *link)
                 link->rcv_unacked = 0;
                 __skb_queue_tail(&link->transmq, skb);
                 tipc_bearer_send(link->owner->net, link->bearer_id,
-                                 skb, &link->media_addr);
+                                 skb, link->media_addr);
         }
         link->snd_nxt = seqno;
 }
@@ -912,7 +896,7 @@ void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
-                                 &l_ptr->media_addr);
+                                 l_ptr->media_addr);
                 retransmits--;
                 l_ptr->stats.retransmitted++;
         }
@@ -1200,7 +1184,7 @@ void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
         skb = __skb_dequeue(&xmitq);
         if (!skb)
                 return;
-        tipc_bearer_send(l->owner->net, l->bearer_id, skb, &l->media_addr);
+        tipc_bearer_send(l->owner->net, l->bearer_id, skb, l->media_addr);
         l->rcv_unacked = 0;
         kfree_skb(skb);
 }
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 39b8c4c5121e..39ff8b6919a4 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -148,7 +148,7 @@ struct tipc_stats {
 struct tipc_link {
         u32 addr;
         char name[TIPC_MAX_LINK_NAME];
-        struct tipc_media_addr media_addr;
+        struct tipc_media_addr *media_addr;
         struct tipc_node *owner;
 
         /* Management and link supervision data */
@@ -205,13 +205,10 @@ struct tipc_link {
         struct tipc_stats stats;
 };
 
-struct tipc_port;
-
-struct tipc_link *tipc_link_create(struct tipc_node *n,
-                                   struct tipc_bearer *b,
-                                   const struct tipc_media_addr *maddr,
-                                   struct sk_buff_head *inputq,
-                                   struct sk_buff_head *namedq);
+bool tipc_link_create(struct tipc_node *n, struct tipc_bearer *b, u32 session,
+                      u32 ownnode, u32 peer, struct tipc_media_addr *maddr,
+                      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
+                      struct tipc_link **link);
 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
                            int mtyp, struct sk_buff_head *xmitq);
 void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
@@ -246,13 +243,8 @@ int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
-void link_prepare_wakeup(struct tipc_link *l);
 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq);
 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                   struct sk_buff_head *xmitq);
-static inline u32 link_own_addr(struct tipc_link *l)
-{
-        return msg_prevnode(l->pmsg);
-}
 
 #endif
diff --git a/net/tipc/node.c b/net/tipc/node.c
index 9e9b0938bd17..7c191641b44f 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -320,10 +320,6 @@ static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
         if (!nl || !tipc_link_is_up(nl))
                 return;
 
-        if (n->working_links > 1) {
-                pr_warn("Attempt to establish 3rd link to %x\n", n->addr);
-                return;
-        }
         n->working_links++;
         n->action_flags |= TIPC_NOTIFY_LINK_UP;
         n->link_id = nl->peer_bearer_id << 16 | bearer_id;
@@ -470,13 +466,13 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 {
         struct tipc_node *n;
         struct tipc_link *l;
-        struct tipc_media_addr *curr_maddr;
-        struct sk_buff_head *inputq;
+        struct tipc_link_entry *le;
         bool addr_match = false;
         bool sign_match = false;
         bool link_up = false;
         bool accept_addr = false;
         bool reset = true;
+
         *dupl_addr = false;
         *respond = false;
 
@@ -486,13 +482,12 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 
         tipc_node_lock(n);
 
-        curr_maddr = &n->links[b->identity].maddr;
-        inputq = &n->links[b->identity].inputq;
+        le = &n->links[b->identity];
 
         /* Prepare to validate requesting node's signature and media address */
-        l = n->links[b->identity].link;
+        l = le->link;
         link_up = l && tipc_link_is_up(l);
-        addr_match = l && !memcmp(curr_maddr, maddr, sizeof(*maddr));
+        addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
         sign_match = (signature == n->signature);
 
         /* These three flags give us eight permutations: */
@@ -559,18 +554,25 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 
         /* Now create new link if not already existing */
         if (!l) {
-                l = tipc_link_create(n, b, maddr, inputq, &n->bclink.namedq);
-                if (!l) {
+                if (n->link_cnt == 2) {
+                        pr_warn("Cannot establish 3rd link to %x\n", n->addr);
+                        goto exit;
+                }
+                if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
+                                      tipc_own_addr(net), onode, &le->maddr,
+                                      &le->inputq, &n->bclink.namedq, &l)) {
                         *respond = false;
                         goto exit;
                 }
+                tipc_link_reset(l);
+                le->link = l;
+                n->link_cnt++;
                 tipc_node_calculate_timer(n, l);
                 if (n->link_cnt == 1)
                         if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
                                 tipc_node_get(n);
         }
-        memcpy(&l->media_addr, maddr, sizeof(*maddr));
-        memcpy(curr_maddr, maddr, sizeof(*maddr));
+        memcpy(&le->maddr, maddr, sizeof(*maddr));
 exit:
         tipc_node_unlock(n);
         if (reset)
@@ -603,24 +605,6 @@ static void tipc_node_reset_links(struct tipc_node *n)
         }
 }
 
-void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
-{
-        n_ptr->links[l_ptr->bearer_id].link = l_ptr;
-        n_ptr->link_cnt++;
-}
-
-void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
-{
-        int i;
-
-        for (i = 0; i < MAX_BEARERS; i++) {
-                if (l_ptr != n_ptr->links[i].link)
-                        continue;
-                n_ptr->links[i].link = NULL;
-                n_ptr->link_cnt--;
-        }
-}
-
 /* tipc_node_fsm_evt - node finite state machine
  * Determines when contact is allowed with peer node
  */