kernel/linux.git/net/tipc/subscr.h, branch linux-4.16.y

tipc: improve groupcast scope handling

2018-01-09T17:35:58+00:00

When a member joins a group, it also indicates a binding scope. This makes it possible to create both node local groups, invisible to other nodes, as well as cluster global groups, visible everywhere. In order to avoid that different members end up having permanently differing views of group size and memberhip, we must inhibit locally and globally bound members from joining the same group. We do this by using the binding scope as an additional separator between groups. I.e., a member must ignore all membership events from sockets using a different scope than itself, and all lookups for message destinations must require an exact match between the message's lookup scope and the potential target's binding scope. Apart from making it possible to create local groups using the same identity on different nodes, a side effect of this is that it now also becomes possible to create a cluster global group with the same identity across the same nodes, without interfering with the local groups. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: adjust the policy of holding subscription kref

2017-03-29T01:03:33+00:00

When a new subscription object is inserted into name_seq->subscriptions list, it's under name_seq->lock protection; when a subscription is deleted from the list, it's also under the same lock protection; similarly, when accessing a subscription by going through subscriptions list, the entire process is also protected by the name_seq->lock. Therefore, if subscription refcount is increased before it's inserted into subscriptions list, and its refcount is decreased after it's deleted from the list, it will be unnecessary to hold refcount at all before accessing subscription object which is obtained by going through subscriptions list under name_seq->lock protection. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: add subscription refcount to avoid invalid delete

2017-01-24T21:14:57+00:00

Until now, the subscribers keep track of the subscriptions using reference count at subscriber level. At subscription cancel or subscriber delete, we delete the subscription only if the timer was pending for the subscription. This approach is incorrect as: 1. del_timer() is not SMP safe, if on CPU0 the check for pending timer returns true but CPU1 might schedule the timer callback thereby deleting the subscription. Thus when CPU0 is scheduled, it deletes an invalid subscription. 2. We export tipc_subscrp_report_overlap(), which accesses the subscription pointer multiple times. Meanwhile the subscription timer can expire thereby freeing the subscription and we might continue to access the subscription pointer leading to memory violations. In this commit, we introduce subscription refcount to avoid deleting an invalid subscription. Reported-and-Tested-by: John Thompson Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: remove struct tipc_name_seq from struct tipc_subscription

2016-02-06T08:40:43+00:00

Until now, struct tipc_subscriber has duplicate fields for type, upper and lower (as member of struct tipc_name_seq) at: 1. as member seq in struct tipc_subscription 2. as member seq in struct tipc_subscr, which is contained in struct tipc_event The former structure contains the type, upper and lower values in network byte order and the later contains the intact copy of the request. The struct tipc_subscription contains a field swap to determine if request needs network byte order conversion. Thus by using swap, we can convert the request when required instead of duplicating it. In this commit, 1. we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. 2. provide new functions to convert the user request into network byte order. Acked-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: remove filter and timeout elements from struct tipc_subscription

2016-02-06T08:40:43+00:00

Until now, struct tipc_subscription has duplicate timeout and filter attributes present: 1. directly as members of struct tipc_subscription 2. in struct tipc_subscr, which is contained in struct tipc_event In this commit, we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. Acked-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: rename functions defined in subscr.c

2015-05-04T19:04:00+00:00

When a topology server accepts a connection request from its client, it allocates a connection instance and a tipc_subscriber structure object. The former is used to communicate with client, and the latter is often treated as a subscriber which manages all subscription events requested from a same client. When a topology server receives a request of subscribing name services from a client through the connection, it creates a tipc_subscription structure instance which is seen as a subscription recording what name services are subscribed. In order to manage all subscriptions from a same client, topology server links them into the subscrp_list of the subscriber. So subscriber and subscription completely represents different meanings respectively, but function names associated with them make us so confused that we are unable to easily tell which function is against subscriber and which is to subscription. So we want to eliminate the confusion by renaming them. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: make subscriber server support net namespace

2015-01-12T21:24:33+00:00

TIPC establishes one subscriber server which allows users to subscribe their interesting name service status. After tipc supports namespace, one dedicated tipc stack instance is created for each namespace, and each instance can be deemed as one independent TIPC node. As a result, subscriber server must be built for each namespace. Signed-off-by: Ying Xue Tested-by: Tero Aho Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: name tipc name table support net namespace

2015-01-12T21:24:33+00:00

TIPC name table is used to store the mapping relationship between TIPC service name and socket port ID. When tipc supports namespace, it allows users to publish service names only owned by a certain namespace. Therefore, every namespace must have its private name table to prevent service names published to one namespace from being contaminated by other service names in another namespace. Therefore, The name table global variable (ie, nametbl) and its lock must be moved to tipc_net structure, and a parameter of namespace must be added for necessary functions so that they can obtain name table variable defined in tipc_net structure. Signed-off-by: Ying Xue Tested-by: Tero Aho Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: cleanup core.c and core.h files

2015-01-12T21:24:31+00:00

Only the works of initializing and shutting down tipc module are done in core.h and core.c files, so all stuffs which are not closely associated with the two tasks should be moved to appropriate places. Signed-off-by: Ying Xue Tested-by: Tero Aho Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: remove unnecessary wrapper functions of kernel timer APIs

2015-01-12T21:24:31+00:00

Not only some wrapper function like k_term_timer() is empty, but also some others including k_start_timer() and k_cancel_timer() don't return back any value to its caller, what's more, there is no any component in the kernel world to do such thing. Therefore, these timer interfaces defined in tipc module should be purged. Signed-off-by: Ying Xue Tested-by: Tero Aho Reviewed-by: Jon Maloy Signed-off-by: David S. Miller