tipc: clean up definitions and usage of link flags
The status flag LINK_STOPPED is not needed any more, since the
mechanism for delayed deletion of links has been removed.
Likewise, LINK_STARTED and LINK_START_EVT are unnecessary,
because we can just as well start the link timer directly from
inside tipc_link_create().
We eliminate these flags in this commit.
Instead of the above flags, we now introduce three new link modes,
TIPC_LINK_OPEN, TIPC_LINK_BLOCKED and TIPC_LINK_TUNNEL. The values
indicate whether, and in the case of TIPC_LINK_TUNNEL, which, messages
the link is allowed to receive in this state. TIPC_LINK_BLOCKED also
blocks timer-driven protocol messages to be sent out, and any change
to the link FSM. Since the modes are mutually exclusive, we convert
them to state values, and rename the 'flags' field in struct tipc_link
to 'exec_mode'.
Finally, we move the #defines for link FSM states and events from link.h
into enums inside the file link.c, which is the real usage scope of
these definitions.
Reviewed-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>
diff --git a/net/tipc/link.c b/net/tipc/link.c
index c052437..35a2da6 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -79,20 +79,50 @@
/*
* Out-of-range value for link session numbers
*/
-#define INVALID_SESSION 0x10000
+#define WILDCARD_SESSION 0x10000
-/*
- * Link state events:
- */
-#define STARTING_EVT 856384768 /* link processing trigger */
-#define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
-#define SILENCE_EVT 560817u /* timer dicovered silence from peer */
-
-/*
- * State value stored in 'failover_pkts'
+/* State value stored in 'failover_pkts'
*/
#define FIRST_FAILOVER 0xffffu
+/* Link FSM states and events:
+ */
+enum {
+ WORKING_WORKING,
+ WORKING_UNKNOWN,
+ RESET_RESET,
+ RESET_UNKNOWN
+};
+
+enum {
+ PEER_RESET_EVT = RESET_MSG,
+ ACTIVATE_EVT = ACTIVATE_MSG,
+ TRAFFIC_EVT, /* Any other valid msg from peer */
+ SILENCE_EVT /* Peer was silent during last timer interval*/
+};
+
+/* Link FSM state checking routines
+ */
+static int link_working_working(struct tipc_link *l)
+{
+ return l->state == WORKING_WORKING;
+}
+
+static int link_working_unknown(struct tipc_link *l)
+{
+ return l->state == WORKING_UNKNOWN;
+}
+
+static int link_reset_unknown(struct tipc_link *l)
+{
+ return l->state == RESET_UNKNOWN;
+}
+
+static int link_reset_reset(struct tipc_link *l)
+{
+ return l->state == RESET_RESET;
+}
+
static void link_handle_out_of_seq_msg(struct tipc_link *link,
struct sk_buff *skb);
static void tipc_link_proto_rcv(struct tipc_link *link,
@@ -268,7 +298,7 @@
/* 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 = INVALID_SESSION;
+ l_ptr->peer_session = WILDCARD_SESSION;
l_ptr->bearer_id = b_ptr->identity;
link_set_supervision_props(l_ptr, b_ptr->tolerance);
l_ptr->state = RESET_UNKNOWN;
@@ -297,8 +327,7 @@
link_reset_statistics(l_ptr);
tipc_node_attach_link(n_ptr, l_ptr);
setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
- link_state_event(l_ptr, STARTING_EVT);
-
+ link_set_timer(l_ptr, l_ptr->keepalive_intv);
return l_ptr;
}
@@ -311,7 +340,6 @@
tipc_link_reset(l);
if (del_timer(&l->timer))
tipc_link_put(l);
- l->flags |= LINK_STOPPED;
/* Delete link now, or when timer is finished: */
tipc_link_reset_fragments(l);
tipc_node_detach_link(l->owner, l);
@@ -438,7 +466,7 @@
msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
/* Link is down, accept any session */
- l_ptr->peer_session = INVALID_SESSION;
+ l_ptr->peer_session = WILDCARD_SESSION;
/* Prepare for renewed mtu size negotiation */
l_ptr->mtu = l_ptr->advertised_mtu;
@@ -452,7 +480,7 @@
tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
- l_ptr->flags |= LINK_FAILINGOVER;
+ l_ptr->exec_mode = TIPC_LINK_BLOCKED;
l_ptr->failover_checkpt = l_ptr->rcv_nxt;
pl->failover_pkts = FIRST_FAILOVER;
pl->failover_checkpt = l_ptr->rcv_nxt;
@@ -496,21 +524,14 @@
static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
{
struct tipc_link *other;
- unsigned long timer_intv = l_ptr->keepalive_intv;
- if (l_ptr->flags & LINK_STOPPED)
- return;
-
- if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
- return; /* Not yet. */
-
- if (l_ptr->flags & LINK_FAILINGOVER)
+ if (l_ptr->exec_mode == TIPC_LINK_BLOCKED)
return;
switch (l_ptr->state) {
case WORKING_WORKING:
switch (event) {
- case TRAFFIC_MSG_EVT:
+ case TRAFFIC_EVT:
case ACTIVATE_MSG:
l_ptr->silent_intv_cnt = 0;
break;
@@ -538,7 +559,7 @@
break;
case WORKING_UNKNOWN:
switch (event) {
- case TRAFFIC_MSG_EVT:
+ case TRAFFIC_EVT:
case ACTIVATE_MSG:
l_ptr->state = WORKING_WORKING;
l_ptr->silent_intv_cnt = 0;
@@ -576,7 +597,7 @@
break;
case RESET_UNKNOWN:
switch (event) {
- case TRAFFIC_MSG_EVT:
+ case TRAFFIC_EVT:
break;
case ACTIVATE_MSG:
other = node_active_link(l_ptr->owner, 0);
@@ -593,10 +614,6 @@
tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
1, 0, 0, 0);
break;
- case STARTING_EVT:
- l_ptr->flags |= LINK_STARTED;
- link_set_timer(l_ptr, timer_intv);
- break;
case SILENCE_EVT:
tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
break;
@@ -606,7 +623,7 @@
break;
case RESET_RESET:
switch (event) {
- case TRAFFIC_MSG_EVT:
+ case TRAFFIC_EVT:
case ACTIVATE_MSG:
other = node_active_link(l_ptr->owner, 0);
if (other && link_working_unknown(other))
@@ -975,7 +992,7 @@
if (skb_queue_len(pl->inputq) > post_synch)
return false;
synched:
- l->flags &= ~LINK_SYNCHING;
+ l->exec_mode = TIPC_LINK_OPEN;
return true;
}
@@ -1091,7 +1108,7 @@
}
/* Traffic message. Conditionally activate link */
- link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+ link_state_event(l_ptr, TRAFFIC_EVT);
if (link_working_working(l_ptr)) {
/* Re-insert buffer in front of queue */
@@ -1112,7 +1129,8 @@
l_ptr->silent_intv_cnt = 0;
/* Synchronize with parallel link if applicable */
- if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
+ if (unlikely((l_ptr->exec_mode == TIPC_LINK_TUNNEL) &&
+ !msg_dup(msg))) {
if (!link_synch(l_ptr))
goto unlock;
}
@@ -1193,7 +1211,7 @@
switch (msg_user(msg)) {
case TUNNEL_PROTOCOL:
if (msg_dup(msg)) {
- link->flags |= LINK_SYNCHING;
+ link->exec_mode = TIPC_LINK_TUNNEL;
link->synch_point = msg_seqno(msg_get_wrapped(msg));
kfree_skb(skb);
break;
@@ -1315,7 +1333,7 @@
u16 last_rcv;
/* Don't send protocol message during link failover */
- if (l_ptr->flags & LINK_FAILINGOVER)
+ if (l_ptr->exec_mode == TIPC_LINK_BLOCKED)
return;
/* Abort non-RESET send if communication with node is prohibited */
@@ -1390,7 +1408,7 @@
u32 msg_tol;
struct tipc_msg *msg = buf_msg(buf);
- if (l_ptr->flags & LINK_FAILINGOVER)
+ if (l_ptr->exec_mode == TIPC_LINK_BLOCKED)
goto exit;
if (l_ptr->net_plane != msg_net_plane(msg))
@@ -1401,7 +1419,7 @@
case RESET_MSG:
if (!link_working_unknown(l_ptr) &&
- (l_ptr->peer_session != INVALID_SESSION)) {
+ (l_ptr->peer_session != WILDCARD_SESSION)) {
if (less_eq(msg_session(msg), l_ptr->peer_session))
break; /* duplicate or old reset: ignore */
}
@@ -1465,7 +1483,7 @@
/* Record reception; force mismatch at next timeout: */
l_ptr->silent_intv_cnt = 0;
- link_state_event(l_ptr, TRAFFIC_MSG_EVT);
+ link_state_event(l_ptr, TRAFFIC_EVT);
l_ptr->stats.recv_states++;
if (link_reset_unknown(l_ptr))
break;
@@ -1704,7 +1722,7 @@
}
exit:
if (!link->failover_pkts && pl)
- pl->flags &= ~LINK_FAILINGOVER;
+ pl->exec_mode = TIPC_LINK_OPEN;
kfree_skb(*skb);
*skb = iskb;
return *skb;