tipc: Add support for customized subscription endianness

This patch enables TIPC's topology server code to do customized
endianness conversions on a per-subscription basis.  (This
capability is needed to support the upcoming consolidation of
subscriber and subscription object references.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 19 deletions

diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 81e2bd5f2413..a62e5d30638c 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -47,7 +47,6 @@
  * @subscriber_list: adjacent subscribers in top. server's list of subscribers
  * @subscription_list: list of subscription objects for this subscriber
  * @port_ref: object reference to port used to communicate with subscriber
- * @swap: indicates if subscriber uses opposite endianness in its messages
  */
 
 struct subscriber {
@@ -56,7 +55,6 @@ struct subscriber {
         struct list_head subscriber_list;
         struct list_head subscription_list;
         u32 port_ref;
-        int swap;
 };
 
 /**
@@ -109,11 +107,11 @@ static void subscr_send_event(struct subscription *sub,
         msg_sect.iov_base = (void *)&sub->evt;
         msg_sect.iov_len = sizeof(struct tipc_event);
 
-        sub->evt.event = htohl(event, sub->owner->swap);
-        sub->evt.found_lower = htohl(found_lower, sub->owner->swap);
-        sub->evt.found_upper = htohl(found_upper, sub->owner->swap);
-        sub->evt.port.ref = htohl(port_ref, sub->owner->swap);
-        sub->evt.port.node = htohl(node, sub->owner->swap);
+        sub->evt.event = htohl(event, sub->swap);
+        sub->evt.found_lower = htohl(found_lower, sub->swap);
+        sub->evt.found_upper = htohl(found_upper, sub->swap);
+        sub->evt.port.ref = htohl(port_ref, sub->swap);
+        sub->evt.port.node = htohl(node, sub->swap);
         tipc_send(sub->owner->port_ref, 1, &msg_sect);
 }
 
@@ -324,18 +322,16 @@ static void subscr_subscribe(struct tipc_subscr *s,
                              struct subscriber *subscriber)
 {
         struct subscription *sub;
+        int swap;
 
-        /* Determine/update subscriber's endianness */
+        /* Determine subscriber's endianness */
 
-        if (s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE))
-                subscriber->swap = 0;
-        else
-                subscriber->swap = 1;
+        swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
 
         /* Detect & process a subscription cancellation request */
 
-        if (s->filter & htohl(TIPC_SUB_CANCEL, subscriber->swap)) {
-                s->filter &= ~htohl(TIPC_SUB_CANCEL, subscriber->swap);
+        if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
+                s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
                 subscr_cancel(s, subscriber);
                 return;
         }
@@ -360,11 +356,11 @@ static void subscr_subscribe(struct tipc_subscr *s,
 
         /* Initialize subscription object */
 
-        sub->seq.type = htohl(s->seq.type, subscriber->swap);
-        sub->seq.lower = htohl(s->seq.lower, subscriber->swap);
-        sub->seq.upper = htohl(s->seq.upper, subscriber->swap);
-        sub->timeout = htohl(s->timeout, subscriber->swap);
-        sub->filter = htohl(s->filter, subscriber->swap);
+        sub->seq.type = htohl(s->seq.type, swap);
+        sub->seq.lower = htohl(s->seq.lower, swap);
+        sub->seq.upper = htohl(s->seq.upper, swap);
+        sub->timeout = htohl(s->timeout, swap);
+        sub->filter = htohl(s->filter, swap);
         if ((!(sub->filter & TIPC_SUB_PORTS)
              == !(sub->filter & TIPC_SUB_SERVICE))
             || (sub->seq.lower > sub->seq.upper)) {
@@ -378,6 +374,7 @@ static void subscr_subscribe(struct tipc_subscr *s,
         INIT_LIST_HEAD(&sub->subscription_list);
         INIT_LIST_HEAD(&sub->nameseq_list);
         list_add(&sub->subscription_list, &subscriber->subscription_list);
+        sub->swap = swap;
         atomic_inc(&topsrv.subscription_count);
         if (sub->timeout != TIPC_WAIT_FOREVER) {
                 k_init_timer(&sub->timer,