kernel/linux.git/net/tipc/group.h, branch v6.18.22

tipc: update address terminology in code

2020-11-28T01:34:01+00:00

We update the terminology in the code so that deprecated structure names and macros are replaced with those currently recommended in the user API. struct tipc_portid -> struct tipc_socket_addr struct tipc_name -> struct tipc_service_addr struct tipc_name_seq -> struct tipc_service_range TIPC_ADDR_ID -> TIPC_SOCKET_ADDR TIPC_ADDR_NAME -> TIPC_SERVICE_ADDR TIPC_ADDR_NAMESEQ -> TIPC_SERVICE_RANGE TIPC_CFG_SRV -> TIPC_NODE_STATE Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: Jakub Kicinski

tipc: extend sock diag for group communication

2018-06-30T12:05:42+00:00

This commit extends the existing TIPC socket diagnostics framework for information related to TIPC group communication. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: GhantaKrishnamurthy MohanKrishna Signed-off-by: David S. Miller

tipc: fix race between poll() and setsockopt()

2018-01-19T20:12:21+00:00

Letting tipc_poll() dereference a socket's pointer to struct tipc_group entails a race risk, as the group item may be deleted in a concurrent tipc_sk_join() or tipc_sk_leave() thread. We now move the 'open' flag in struct tipc_group to struct tipc_sock, and let the former retain only a pointer to the moved field. This will eliminate the race risk. Reported-by: syzbot+799dafde0286795858ac@syzkaller.appspotmail.com Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: improve poll() for group member socket

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

The current criteria for returning POLLOUT from a group member socket is too simplistic. It basically returns POLLOUT as soon as the group has external destinations, something obviously leading to a lot of spinning during destination congestion situations. At the same time, the internal congestion handling is unnecessarily complex. We now change this as follows. - We introduce an 'open' flag in struct tipc_group. This flag is used only to help poll() get the setting of POLLOUT right, and *not* for congeston handling as such. This means that a user can choose to ignore an EAGAIN for a destination and go on sending messages to other destinations in the group if he wants to. - The flag is set to false every time we return EAGAIN on a send call. - The flag is set to true every time any member, i.e., not necessarily the member that caused EAGAIN, is removed from the small_win list. - We remove the group member 'usr_pending' flag. The size of the send window and presence in the 'small_win' list is sufficient criteria for recognizing congestion. This solution seems to be a reasonable compromise between 'anycast', which is normally not waiting for POLLOUT for a specific destination, and the other three send modes, which are. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: send out join messages as soon as new member is discovered

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

When a socket is joining a group, we look up in the binding table to find if there are already other members of the group present. This is used for being able to return EAGAIN instead of EHOSTUNREACH if the user proceeds directly to a send attempt. However, the information in the binding table can be used to directly set the created member in state MBR_PUBLISHED and send a JOIN message to the peer, instead of waiting for a topology PUBLISH event to do this. When there are many members in a group, the propagation time for such events can be significant, and we can save time during the join operation if we use the initial lookup result fully. In this commit, we eliminate the member state MBR_DISCOVERED which has been the result of the initial lookup, and do instead go directly to MBR_PUBLISHED, which initiates the setup. After this change, the tipc_member FSM looks as follows: +-----------+ ---->| PUBLISHED |-----------------------------------------------+ PUB- +-----------+ LEAVE/WITHRAW | LISH |JOIN | | +-------------------------------------------+ | | | LEAVE/WITHDRAW | | | | +------------+ | | | | +----------->| PENDING |---------+ | | | | |msg/maxactv +-+---+------+ LEAVE/ | | | | | | | | WITHDRAW | | | | | | +----------+ | | | | | | | |revert/maxactv| | | | | | | V V V V V | +----------+ msg +------------+ +-----------+ +-->| JOINED |------>| ACTIVE |------>| LEAVING |---> | +----------+ +--- -+------+ LEAVE/+-----------+DOWN | A A | WITHDRAW A A A EVT | | | |RECLAIM | | | | | |REMIT V | | | | | |== adv +------------+ | | | | | +---------| RECLAIMING |--------+ | | | | +-----+------+ LEAVE/ | | | | |REMIT WITHDRAW | | | | |< adv | | | |msg/ V LEAVE/ | | | |adv==ADV_IDLE+------------+ WITHDRAW | | | +-------------| REMITTED |------------+ | | +------------+ | |PUBLISH | JOIN +-----------+ LEAVE/WITHDRAW | ---->| JOINING |-----------------------------------------------+ +-----------+ Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: create group member event messages when they are needed

2018-01-09T17:35:57+00:00

In the current implementation, a group socket receiving topology events about other members just converts the topology event message into a group event message and stores it until it reaches the right state to issue it to the user. This complicates the code unnecessarily, and becomes impractical when we in the coming commits will need to create and issue membership events independently. In this commit, we change this so that we just notice the type and origin of the incoming topology event, and then drop the buffer. Only when it is time to actually send a group event to the user do we explicitly create a new message and send it upwards. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: guarantee that group broadcast doesn't bypass group unicast

2017-10-13T15:46:01+00:00

We need a mechanism guaranteeing that group unicasts sent out from a socket are not bypassed by later sent broadcasts from the same socket. We do this as follows: - Each time a unicast is sent, we set a the broadcast method for the socket to "replicast" and "mandatory". This forces the first subsequent broadcast message to follow the same network and data path as the preceding unicast to a destination, hence preventing it from overtaking the latter. - In order to make the 'same data path' statement above true, we let group unicasts pass through the multicast link input queue, instead of as previously through the unicast link input queue. - In the first broadcast following a unicast, we set a new header flag, requiring all recipients to immediately acknowledge its reception. - During the period before all the expected acknowledges are received, the socket refuses to accept any more broadcast attempts, i.e., by blocking or returning EAGAIN. This period should typically not be longer than a few microseconds. - When all acknowledges have been received, the sending socket will open up for subsequent broadcasts, this time giving the link layer freedom to itself select the best transmission method. - The forced and/or abrupt transmission method changes described above may lead to broadcasts arriving out of order to the recipients. We remedy this by introducing code that checks and if necessary re-orders such messages at the receiving end. Signed-off-by: Jon Maloy Acked-by: Ying Xue Signed-off-by: David S. Miller

tipc: introduce group anycast messaging

2017-10-13T15:46:00+00:00

In this commit, we make it possible to send connectionless unicast messages to any member corresponding to the given member identity, when there is more than one such member. The sender must use a TIPC_ADDR_NAME address to achieve this effect. We also perform load balancing between the destinations, i.e., we primarily select one which has advertised sufficient send window to not cause a block/EAGAIN delay, if any. This mechanism is overlayed on the always present round-robin selection. Anycast messages are subject to the same start synchronization and flow control mechanism as group broadcast messages. Signed-off-by: Jon Maloy Acked-by: Ying Xue Signed-off-by: David S. Miller

tipc: introduce group unicast messaging

2017-10-13T15:46:00+00:00

We now make it possible to send connectionless unicast messages within a communication group. To send a message, the sender can use either a direct port address, aka port identity, or an indirect port name to be looked up. This type of messages are subject to the same start synchronization and flow control mechanism as group broadcast messages. Signed-off-by: Jon Maloy Acked-by: Ying Xue Signed-off-by: David S. Miller

tipc: introduce flow control for group broadcast messages

2017-10-13T15:46:00+00:00

We introduce an end-to-end flow control mechanism for group broadcast messages. This ensures that no messages are ever lost because of destination receive buffer overflow, with minimal impact on performance. For now, the algorithm is based on the assumption that there is only one active transmitter at any moment in time. Signed-off-by: Jon Maloy Acked-by: Ying Xue Signed-off-by: David S. Miller