diff options
| -rw-r--r-- | include/linux/tipc.h | 1 | ||||
| -rw-r--r-- | net/tipc/subscr.c | 99 |
2 files changed, 85 insertions, 15 deletions
diff --git a/include/linux/tipc.h b/include/linux/tipc.h index 243a15f5400..bea469455a0 100644 --- a/include/linux/tipc.h +++ b/include/linux/tipc.h @@ -129,6 +129,7 @@ static inline unsigned int tipc_node(__u32 addr) #define TIPC_SUB_PORTS 0x01 /* filter for port availability */ #define TIPC_SUB_SERVICE 0x02 /* filter for service availability */ +#define TIPC_SUB_CANCEL 0x04 /* cancel a subscription */ #if 0 /* The following filter options are not currently implemented */ #define TIPC_SUB_NO_BIND_EVTS 0x04 /* filter out "publish" events */ diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c index c51600ba5f4..7a918f12a5d 100644 --- a/net/tipc/subscr.c +++ b/net/tipc/subscr.c @@ -155,7 +155,7 @@ void tipc_subscr_report_overlap(struct subscription *sub, sub->seq.upper, found_lower, found_upper); if (!tipc_subscr_overlap(sub, found_lower, found_upper)) return; - if (!must && (sub->filter != TIPC_SUB_PORTS)) + if (!must && !(sub->filter & TIPC_SUB_PORTS)) return; subscr_send_event(sub, found_lower, found_upper, event, port_ref, node); } @@ -176,6 +176,13 @@ static void subscr_timeout(struct subscription *sub) if (subscriber == NULL) return; + /* Validate timeout (in case subscription is being cancelled) */ + + if (sub->timeout == TIPC_WAIT_FOREVER) { + tipc_ref_unlock(subscriber_ref); + return; + } + /* Unlink subscription from name table */ tipc_nametbl_unsubscribe(sub); @@ -199,6 +206,20 @@ static void subscr_timeout(struct subscription *sub) } /** + * subscr_del - delete a subscription within a subscription list + * + * Called with subscriber locked. + */ + +static void subscr_del(struct subscription *sub) +{ + tipc_nametbl_unsubscribe(sub); + list_del(&sub->subscription_list); + kfree(sub); + atomic_dec(&topsrv.subscription_count); +} + +/** * subscr_terminate - terminate communication with a subscriber * * Called with subscriber locked. Routine must temporarily release this lock @@ -227,12 +248,9 @@ static void subscr_terminate(struct subscriber *subscriber) k_cancel_timer(&sub->timer); k_term_timer(&sub->timer); } - tipc_nametbl_unsubscribe(sub); - list_del(&sub->subscription_list); - dbg("Term: Removed sub %u,%u,%u from subscriber %x list\n", + dbg("Term: Removing sub %u,%u,%u from subscriber %x list\n", sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); - kfree(sub); - atomic_dec(&topsrv.subscription_count); + subscr_del(sub); } /* Sever connection to subscriber */ @@ -253,6 +271,49 @@ static void subscr_terminate(struct subscriber *subscriber) } /** + * subscr_cancel - handle subscription cancellation request + * + * Called with subscriber locked. Routine must temporarily release this lock + * to enable the subscription timeout routine to finish without deadlocking; + * the lock is then reclaimed to allow caller to release it upon return. + * + * Note that fields of 's' use subscriber's endianness! + */ + +static void subscr_cancel(struct tipc_subscr *s, + struct subscriber *subscriber) +{ + struct subscription *sub; + struct subscription *sub_temp; + int found = 0; + + /* Find first matching subscription, exit if not found */ + + list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, + subscription_list) { + if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) { + found = 1; + break; + } + } + if (!found) + return; + + /* Cancel subscription timer (if used), then delete subscription */ + + if (sub->timeout != TIPC_WAIT_FOREVER) { + sub->timeout = TIPC_WAIT_FOREVER; + spin_unlock_bh(subscriber->lock); + k_cancel_timer(&sub->timer); + k_term_timer(&sub->timer); + spin_lock_bh(subscriber->lock); + } + dbg("Cancel: removing sub %u,%u,%u from subscriber %x list\n", + sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); + subscr_del(sub); +} + +/** * subscr_subscribe - create subscription for subscriber * * Called with subscriber locked @@ -263,6 +324,21 @@ static void subscr_subscribe(struct tipc_subscr *s, { struct subscription *sub; + /* Determine/update subscriber's endianness */ + + if (s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE)) + subscriber->swap = 0; + else + subscriber->swap = 1; + + /* Detect & process a subscription cancellation request */ + + if (s->filter & htohl(TIPC_SUB_CANCEL, subscriber->swap)) { + s->filter &= ~htohl(TIPC_SUB_CANCEL, subscriber->swap); + subscr_cancel(s, subscriber); + return; + } + /* Refuse subscription if global limit exceeded */ if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) { @@ -281,13 +357,6 @@ static void subscr_subscribe(struct tipc_subscr *s, return; } - /* Determine/update subscriber's endianness */ - - if ((s->filter == TIPC_SUB_PORTS) || (s->filter == TIPC_SUB_SERVICE)) - subscriber->swap = 0; - else - subscriber->swap = 1; - /* Initialize subscription object */ memset(sub, 0, sizeof(*sub)); @@ -296,8 +365,8 @@ static void subscr_subscribe(struct tipc_subscr *s, sub->seq.upper = htohl(s->seq.upper, subscriber->swap); sub->timeout = htohl(s->timeout, subscriber->swap); sub->filter = htohl(s->filter, subscriber->swap); - if ((((sub->filter != TIPC_SUB_PORTS) - && (sub->filter != TIPC_SUB_SERVICE))) + if ((!(sub->filter & TIPC_SUB_PORTS) + == !(sub->filter & TIPC_SUB_SERVICE)) || (sub->seq.lower > sub->seq.upper)) { warn("Subscription rejected, illegal request\n"); kfree(sub); |