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2016-07-15rxrpc: checking for IS_ERR() instead of NULLDan Carpenter
The rxrpc_lookup_peer() function returns NULL on error, it never returns error pointers. Fixes: 8496af50eb38 ('rxrpc: Use RCU to access a peer's service connection tree') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-12rxrpc: Fix error handling in af_rxrpc_init()Wei Yongjun
security initialized after alloc workqueue, so we should exit security before destroy workqueue in the error handing. Fixes: 648af7fca159 ("rxrpc: Absorb the rxkad security module") Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-06rxrpc: Kill off the call hash tableDavid Howells
The call hash table is now no longer used as calls are looked up directly by channel slot on the connection, so kill it off. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Use RCU to access a peer's service connection treeDavid Howells
Move to using RCU access to a peer's service connection tree when routing an incoming packet. This is done using a seqlock to trigger retrying of the tree walk if a change happened. Further, we no longer get a ref on the connection looked up in the data_ready handler unless we queue the connection's work item - and then only if the refcount > 0. Note that I'm avoiding the use of a hash table for service connections because each service connection is addressed by a 62-bit number (constructed from epoch and connection ID >> 2) that would allow the client to engage in bucket stuffing, given knowledge of the hash algorithm. Peers, however, are hashed as the network address is less controllable by the client. The total number of peers will also be limited in a future commit. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Move data_ready peer lookup into rxrpc_find_connection()David Howells
Move the peer lookup done in input.c by data_ready into rxrpc_find_connection(). Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Prune the contents of the rxrpc_conn_proto structDavid Howells
Prune the contents of the rxrpc_conn_proto struct. Most of the fields aren't used anymore. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Maintain an extra ref on a conn for the cache listDavid Howells
Overhaul the usage count accounting for the rxrpc_connection struct to make it easier to implement RCU access from the data_ready handler. The problem is that currently we're using a lock to prevent the garbage collector from trying to clean up a connection that we're contemplating unidling. We could just stick incoming packets on the connection we find, but we've then got a problem that we may race when dispatching a work item to process it as we need to give that a ref to prevent the rxrpc_connection struct from disappearing in the meantime. Further, incoming packets may get discarded if attached to an rxrpc_connection struct that is going away. Whilst this is not a total disaster - the client will presumably resend - it would delay processing of the call. This would affect the AFS client filesystem's service manager operation. To this end: (1) We now maintain an extra count on the connection usage count whilst it is on the connection list. This mean it is not in use when its refcount is 1. (2) When trying to reuse an old connection, we only increment the refcount if it is greater than 0. If it is 0, we replace it in the tree with a new candidate connection. (3) Two connection flags are added to indicate whether or not a connection is in the local's client connection tree (used by sendmsg) or the peer's service connection tree (used by data_ready). This makes sure that we don't try and remove a connection if it got replaced. The flags are tested under lock with the removal operation to prevent the reaper from killing the rxrpc_connection struct whilst someone else is trying to effect a replacement. This could probably be alleviated by using memory barriers between the flag set/test and the rb_tree ops. The rb_tree op would still need to be under the lock, however. (4) When trying to reap an old connection, we try to flip the usage count from 1 to 0. If it's not 1 at that point, then it must've come back to life temporarily and we ignore it. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Move peer lookup from call-accept to new-incoming-connDavid Howells
Move the lookup of a peer from a call that's being accepted into the function that creates a new incoming connection. This will allow us to avoid incrementing the peer's usage count in some cases in future. Note that I haven't bother to integrate rxrpc_get_addr_from_skb() with rxrpc_extract_addr_from_skb() as I'm going to delete the former in the very near future. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Split service connection code out into its own fileDavid Howells
Split the service-specific connection code out into into its own file. The client-specific code has already been split out. This will leave just the common code in the original file. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Split client connection code out into its own fileDavid Howells
Split the client-specific connection code out into its own file. It will behave somewhat differently from the service-specific connection code, so it makes sense to separate them. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Call channels should have separate call number spacesDavid Howells
Each channel on a connection has a separate, independent number space from which to allocate callNumber values. It is entirely possible, for example, to have a connection with four active calls, each with call number 1. Note that the callNumber values for any particular channel don't have to start at 1, but they are supposed to increment monotonically for that channel from a client's perspective and may not be reused once the call number is transmitted (until the epoch cycles all the way back round). Currently, however, call numbers are allocated on a per-connection basis and, further, are held in an rb-tree. The rb-tree is redundant as the four channel pointers in the rxrpc_connection struct are entirely capable of pointing to all the calls currently in progress on a connection. To this end, make the following changes: (1) Handle call number allocation independently per channel. (2) Get rid of the conn->calls rb-tree. This is overkill as a connection may have a maximum of four calls in progress at any one time. Use the pointers in the channels[] array instead, indexed by the channel number from the packet. (3) For each channel, save the result of the last call that was in progress on that channel in conn->channels[] so that the final ACK or ABORT packet can be replayed if necessary. Any call earlier than that is just ignored. If we've seen the next call number in a packet, the last one is most definitely defunct. (4) When generating a RESPONSE packet for a connection, the call number counter for each channel must be included in it. (5) When parsing a RESPONSE packet for a connection, the call number counters contained therein should be used to set the minimum expected call numbers on each channel. To do in future commits: (1) Replay terminal packets based on the last call stored in conn->channels[]. (2) Connections should be retired before the callNumber space on any channel runs out. (3) A server is expected to disregard or reject any new incoming call that has a call number less than the current call number counter. The call number counter for that channel must be advanced to the new call number. Note that the server cannot just require that the next call that it sees on a channel be exactly the call number counter + 1 because then there's a scenario that could cause a problem: The client transmits a packet to initiate a connection, the network goes out, the server sends an ACK (which gets lost), the client sends an ABORT (which also gets lost); the network then reconnects, the client then reuses the call number for the next call (it doesn't know the server already saw the call number), but the server thinks it already has the first packet of this call (it doesn't know that the client doesn't know that it saw the call number the first time). Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Access socket accept queue under right lockDavid Howells
The socket's accept queue (socket->acceptq) should be accessed under socket->call_lock, not under the connection lock. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Add RCU destruction for connections and callsDavid Howells
Add RCU destruction for connections and calls as the RCU lookup from the transport socket data_ready handler is going to come along shortly. Whilst we're at it, move the cleanup workqueue flushing and RCU barrierage into the destruction code for the objects that need it (locals and connections) and add the extra RCU barrier required for connection cleanup. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Release a call's connection ref on call disconnectionDavid Howells
When a call is disconnected, clear the call's pointer to the connection and release the associated ref on that connection. This means that the call no longer pins the connection and the connection can be discarded even before the call is. As the code currently stands, the call struct is effectively pinned by userspace until userspace has enacted a recvmsg() to retrieve the final call state as sk_buffs on the receive queue pin the call to which they're related because: (1) The rxrpc_call struct contains the userspace ID that recvmsg() has to include in the control message buffer to indicate which call is being referred to. This ID must remain valid until the terminal packet is completely read and must be invalidated immediately at that point as userspace is entitled to immediately reuse it. (2) The final ACK to the reply to a client call isn't sent until the last data packet is entirely read (it's probably worth altering this in future to be send the ACK as soon as all the data has been received). This change requires a bit of rearrangement to make sure that the call isn't going to try and access the connection again after protocol completion: (1) Delete the error link earlier when we're releasing the call. Possibly network errors should be distributed via connections at the cost of adding in an access to the rxrpc_connection struct. (2) Remove the call from the connection's call tree before disconnecting the call. The call tree needs to be removed anyway and incoming packets delivered by channel pointer instead. (3) The release call event should be considered last after all other events have been processed so that we don't need access to the connection again. (4) Move the channel_lock taking from rxrpc_release_call() to rxrpc_disconnect_call() where it will be required in future. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Fix handling of connection failure in client call creationDavid Howells
If rxrpc_connect_call() fails during the creation of a client connection, there are two bugs that we can hit that need fixing: (1) The call state should be moved to RXRPC_CALL_DEAD before the call cleanup phase is invoked. If not, this can cause an assertion failure later. (2) call->link should be reinitialised after being deleted in rxrpc_new_client_call() - which otherwise leads to a failure later when the call cleanup attempts to delete the link again. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Move usage count getting into rxrpc_queue_conn()David Howells
Rather than calling rxrpc_get_connection() manually before calling rxrpc_queue_conn(), do it inside the queue wrapper. This allows us to do some important fixes: (1) If the usage count is 0, do nothing. This prevents connections from being reanimated once they're dead. (2) If rxrpc_queue_work() fails because the work item is already queued, retract the usage count increment which would otherwise be lost. (3) Don't take a ref on the connection in the work function. By passing the ref through the work item, this is unnecessary. Doing it in the work function is too late anyway. Previously, connection-directed packets held a ref on the connection, but that's not really the best idea. And another useful changes: (*) Don't need to take a refcount on the connection in the data_ready handler unless we invoke the connection's work item. We're using RCU there so that's otherwise redundant. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Check that the client conns cache is empty before module removalDavid Howells
Check that the client conns cache is empty before module removal and bug if not, listing any offending connections that are still present. Unfortunately, if there are connections still around, then the transport socket is still unexpectedly open and active, so we can't just unallocate the connections. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Turn connection #defines into enums and put outside struct defDavid Howells
Turn the connection event and state #define lists into enums and move outside of the struct definition. Whilst we're at it, change _SERVER to _SERVICE in those identifiers and add EV_ into the event name to distinguish them from flags and states. Also add a symbol indicating the number of states and use that in the state text array. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Provide queuing helper functionsDavid Howells
Provide queueing helper functions so that the queueing of local and connection objects can be fixed later. The issue is that a ref on the object needs to be passed to the work queue, but the act of queueing the object may fail because the object is already queued. Testing the queuedness of an object before hand doesn't work because there can be a race with someone else trying to queue it. What will have to be done is to adjust the refcount depending on the result of the queue operation. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Avoid using stack memory in SG lists in rxkadHerbert Xu
rxkad uses stack memory in SG lists which would not work if stacks were allocated from vmalloc memory. In fact, in most cases this isn't even necessary as the stack memory ends up getting copied over to kmalloc memory. This patch eliminates all the unnecessary stack memory uses by supplying the final destination directly to the crypto API. In two instances where a temporary buffer is actually needed we also switch use a scratch area in the rxrpc_call struct (only one DATA packet will be being secured or verified at a time). Finally there is no need to split a split-page buffer into two SG entries so code dealing with that has been removed. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Check the source of a packet to a client connDavid Howells
When looking up a client connection to which to route a packet, we need to check that the packet came from the correct source so that a peer can't try to muck around with another peer's connection. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Fix some sparse errorsDavid Howells
Fix the following sparse errors: ../net/rxrpc/conn_object.c:77:17: warning: incorrect type in assignment (different base types) ../net/rxrpc/conn_object.c:77:17: expected restricted __be32 [usertype] call_id ../net/rxrpc/conn_object.c:77:17: got unsigned int [unsigned] [usertype] call_id ../net/rxrpc/conn_object.c:84:21: warning: restricted __be32 degrades to integer ../net/rxrpc/conn_object.c:86:26: warning: restricted __be32 degrades to integer ../net/rxrpc/conn_object.c:357:15: warning: incorrect type in assignment (different base types) ../net/rxrpc/conn_object.c:357:15: expected restricted __be32 [usertype] epoch ../net/rxrpc/conn_object.c:357:15: got unsigned int [unsigned] [usertype] epoch ../net/rxrpc/conn_object.c:369:21: warning: restricted __be32 degrades to integer ../net/rxrpc/conn_object.c:371:26: warning: restricted __be32 degrades to integer ../net/rxrpc/conn_object.c:411:21: warning: restricted __be32 degrades to integer ../net/rxrpc/conn_object.c:413:26: warning: restricted __be32 degrades to integer Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-01rxrpc: Fix processing of authenticated/encrypted jumbo packetsDavid Howells
When a jumbo packet is being split up and processed, the crypto checksum for each split-out packet is in the jumbo header and needs placing in the reconstructed packet header. When the code was changed to keep the stored copy of the packet header in host byte order, this reconstruction was missed. Found with sparse with CF=-D__CHECK_ENDIAN__: ../net/rxrpc/input.c:479:33: warning: incorrect type in assignment (different base types) ../net/rxrpc/input.c:479:33: expected unsigned short [unsigned] [usertype] _rsvd ../net/rxrpc/input.c:479:33: got restricted __be16 [addressable] [usertype] _rsvd Fixes: 0d12f8a4027d021c9cc942f09f38d28288020c5d ("rxrpc: Keep the skb private record of the Rx header in host byte order") Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Kill off the rxrpc_transport structDavid Howells
The rxrpc_transport struct is now redundant, given that the rxrpc_peer struct is now per peer port rather than per peer host, so get rid of it. Service connection lists are transferred to the rxrpc_peer struct, as is the conn_lock. Previous patches moved the client connection handling out of the rxrpc_transport struct and discarded the connection bundling code. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Kill the client connection bundle conceptDavid Howells
Kill off the concept of maintaining a bundle of connections to a particular target service to increase the number of call slots available for any beyond four for that service (there are four call slots per connection). This will make cleaning up the connection handling code easier and facilitate removal of the rxrpc_transport struct. Bundling can be reintroduced later if necessary. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Provide more refcount helper functionsDavid Howells
Provide refcount helper functions for connections so that the code doesn't touch local or connection usage counts directly. Also make it such that local and peer put functions can take a NULL pointer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Make rxrpc_send_packet() take a connection not a transportDavid Howells
Make rxrpc_send_packet() take a connection not a transport as part of the phasing out of the rxrpc_transport struct. Whilst we're at it, rename the function to rxrpc_send_data_packet() to differentiate it from the other packet sending functions. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Calls displayed in /proc may in future lack a connectionDavid Howells
Allocated rxrpc calls displayed in /proc/net/rxrpc_calls may in future be on the proc list before they're connected or after they've been disconnected - in which case they may not have a pointer to a connection struct that can be used to get data from there. Deal with this by using stuff from the call struct in preference where possible and printing "no_connection" rather than a peer address if no connection is assigned. This change also has the added bonus that the service ID is now taken from the call rather the connection which will allow per-call service upgrades to be shown - something required for AuriStor server compatibility. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Validate the net address given to rxrpc_kernel_begin_call()David Howells
Validate the net address given to rxrpc_kernel_begin_call() before using it. Whilst this should be mostly unnecessary for in-kernel users, it does clear the tail of the address struct in case we want to hash or compare the whole thing. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Use IDR to allocate client conn IDs on a machine-wide basisDavid Howells
Use the IDR facility to allocate client connection IDs on a machine-wide basis so that each client connection has a unique identifier. When the connection ID space wraps, we advance the epoch by 1, thereby effectively having a 62-bit ID space. The IDR facility is then used to look up client connections during incoming packet routing instead of using an rbtree rooted on the transport. This change allows for the removal of the transport in the future and also means that client connections can be looked up directly in the data-ready handler by connection ID. The ID management code is placed in a new file, conn-client.c, to which all the client connection-specific code will eventually move. Note that the IDR tree gets very expensive on memory if the connection IDs are widely scattered throughout the number space, so we shall need to retire connections that have, say, an ID more than four times the maximum number of client conns away from the current allocation point to try and keep the IDs concentrated. We will also need to retire connections from an old epoch. Also note that, for the moment, a pointer to the transport has to be passed through into the ID allocation function so that we can take a BH lock to prevent a locking issue against in-BH lookup of client connections. This will go away later when RCU is used for server connections also. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: rxrpc_connection_lock shouldn't be a BH lock, but conn_lock isDavid Howells
rxrpc_connection_lock shouldn't be accessed as a BH-excluding lock. It's only accessed in a few places and none of those are in BH-context. rxrpc_transport::conn_lock, however, *is* a BH-excluding lock and should be accessed so consistently. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Pass sk_buff * rather than rxrpc_host_header * to functionsDavid Howells
Pass a pointer to struct sk_buff rather than struct rxrpc_host_header to functions so that they can in the future get at transport protocol parameters rather than just RxRPC parameters. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Fix exclusive connection handlingDavid Howells
"Exclusive connections" are meant to be used for a single client call and then scrapped. The idea is to limit the use of the negotiated security context. The current code, however, isn't doing this: it is instead restricting the socket to a single virtual connection and doing all the calls over that. This is changed such that the socket no longer maintains a special virtual connection over which it will do all the calls, but rather gets a new one each time a new exclusive call is made. Further, using a socket option for this is a poor choice. It should be done on sendmsg with a control message marker instead so that calls can be marked exclusive individually. To that end, add RXRPC_EXCLUSIVE_CALL which, if passed to sendmsg() as a control message element, will cause the call to be done on an single-use connection. The socket option (RXRPC_EXCLUSIVE_CONNECTION) still exists and, if set, will override any lack of RXRPC_EXCLUSIVE_CALL being specified so that programs using the setsockopt() will appear to work the same. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Replace conn->trans->{local,peer} with conn->params.{local,peer}David Howells
Replace accesses of conn->trans->{local,peer} with conn->params.{local,peer} thus making it easier for a future commit to remove the rxrpc_transport struct. This also reduces the number of memory accesses involved. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Use structs to hold connection params and protocol infoDavid Howells
Define and use a structure to hold connection parameters. This makes it easier to pass multiple connection parameters around. Define and use a structure to hold protocol information used to hash a connection for lookup on incoming packet. Most of these fields will be disposed of eventually, including the duplicate local pointer. Whilst we're at it rename "proto" to "family" when referring to a protocol family. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: fix uninitialized variable useArnd Bergmann
Hashing the peer key was introduced for AF_INET, but gcc warns about the rxrpc_peer_hash_key function returning uninitialized data for any other value of srx->transport.family: net/rxrpc/peer_object.c: In function 'rxrpc_peer_hash_key': net/rxrpc/peer_object.c:57:15: error: 'p' may be used uninitialized in this function [-Werror=maybe-uninitialized] Assuming that nothing else can be set here, this changes the function to just return zero in case of an unknown address family. Fixes: be6e6707f6ee ("rxrpc: Rework peer object handling to use hash table and RCU") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: checking for IS_ERR() instead of NULLDan Carpenter
rxrpc_lookup_peer_rcu() and rxrpc_lookup_peer() return NULL on error, never error pointers, so IS_ERR() can't be used. Fix three callers of those functions. Fixes: be6e6707f6ee ('rxrpc: Rework peer object handling to use hash table and RCU') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Rework local endpoint managementDavid Howells
Rework the local RxRPC endpoint management. Local endpoint objects are maintained in a flat list as before. This should be okay as there shouldn't be more than one per open AF_RXRPC socket (there can be fewer as local endpoints can be shared if their local service ID is 0 and they share the same local transport parameters). Changes: (1) Local endpoints may now only be shared if they have local service ID 0 (ie. they're not being used for listening). This prevents a scenario where process A is listening of the Cache Manager port and process B contacts a fileserver - which may then attempt to send CM requests back to B. But if A and B are sharing a local endpoint, A will get the CM requests meant for B. (2) We use a mutex to handle lookups and don't provide RCU-only lookups since we only expect to access the list when opening a socket or destroying an endpoint. The local endpoint object is pointed to by the transport socket's sk_user_data for the life of the transport socket - allowing us to refer to it directly from the sk_data_ready and sk_error_report callbacks. (3) atomic_inc_not_zero() now exists and can be used to only share a local endpoint if the last reference hasn't yet gone. (4) We can remove rxrpc_local_lock - a spinlock that had to be taken with BH processing disabled given that we assume sk_user_data won't change under us. (5) The transport socket is shut down before we clear the sk_user_data pointer so that we can be sure that the transport socket's callbacks won't be invoked once the RCU destruction is scheduled. (6) Local endpoints have a work item that handles both destruction and event processing. The means that destruction doesn't then need to wait for event processing. The event queues can then be cleared after the transport socket is shut down. (7) Local endpoints are no longer available for resurrection beyond the life of the sockets that had them open. As soon as their last ref goes, they are scheduled for destruction and may not have their usage count moved from 0. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Separate local endpoint event handling out into its own fileDavid Howells
Separate local endpoint event handling out into its own file preparatory to overhauling the object management aspect (which remains in the original file). Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Use the peer record to distribute network errorsDavid Howells
Use the peer record to distribute network errors rather than the transport object (which I want to get rid of). An error from a particular peer terminates all calls on that peer. For future consideration: (1) For ICMP-induced errors it might be worth trying to extract the RxRPC header from the offending packet, if one is returned attached to the ICMP packet, to better direct the error. This may be overkill, though, since an ICMP packet would be expected to be relating to the destination port, machine or network. RxRPC ABORT and BUSY packets give notice at RxRPC level. (2) To also abort connection-level communications (such as CHALLENGE packets) where indicted by an error - but that requires some revamping of the connection event handling first. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Do a little bit of tidying in the ICMP processingDavid Howells
Do a little bit of tidying in the ICMP processing code. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Don't assume anything about the address in an ICMP packetDavid Howells
Don't assume anything about the address in an ICMP packet in rxrpc_error_report() as the address may not be IPv4 in future, especially since we're just printing these details. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Break MTU determination from ICMP into its own functionDavid Howells
Break MTU determination from ICMP out into its own function to reduce the complexity of the error report handler. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Rename rxrpc_UDP_error_report() to rxrpc_error_report()David Howells
Rename rxrpc_UDP_error_report() to rxrpc_error_report() as it might get called for something other than UDP. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Rework peer object handling to use hash table and RCUDavid Howells
Rework peer object handling to use a hash table instead of a flat list and to use RCU. Peer objects are no longer destroyed by passing them to a workqueue to process, but rather are just passed to the RCU garbage collector as kfree'able objects. The hash function uses the local endpoint plus all the components of the remote address, except for the RxRPC service ID. Peers thus represent a UDP port on the remote machine as contacted by a UDP port on this machine. The RCU read lock is used to handle non-creating lookups so that they can be called from bottom half context in the sk_error_report handler without having to lock the hash table against modification. rxrpc_lookup_peer_rcu() *does* take a reference on the peer object as in the future, this will be passed to a work item for error distribution in the error_report path and this function will cease being used in the data_ready path. Creating lookups are done under spinlock rather than mutex as they might be set up due to an external stimulus if the local endpoint is a server. Captured network error messages (ICMP) are handled with respect to this struct and MTU size and RTT are cached here. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-13rxrpc: Update the comments in ar-internal.h to reflect renamesDavid Howells
Update the section comments in ar-internal.h that indicate the locations of the referenced items to reflect the renames done to the .c files in net/rxrpc/. This also involves some rearrangement to reflect keep the sections in order of filename. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-13rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefixDavid Howells
Rename files matching net/rxrpc/ar-*.c to get rid of the "ar-" prefix. This will aid splitting those files by making easier to come up with new names. Note that the not all files are simply renamed from ar-X.c to X.c. The following exceptions are made: (*) ar-call.c -> call_object.c ar-ack.c -> call_event.c call_object.c is going to contain the core of the call object handling. Call event handling is all going to be in call_event.c. (*) ar-accept.c -> call_accept.c Incoming call handling is going to be here. (*) ar-connection.c -> conn_object.c ar-connevent.c -> conn_event.c The former file is going to have the basic connection object handling, but there will likely be some differentiation between client connections and service connections in additional files later. The latter file will have all the connection-level event handling. (*) ar-local.c -> local_object.c This will have the local endpoint object handling code. The local endpoint event handling code will later be split out into local_event.c. (*) ar-peer.c -> peer_object.c This will have the peer endpoint object handling code. Peer event handling code will be placed in peer_event.c (for the moment, there is none). (*) ar-error.c -> peer_event.c This will become the peer event handling code, though for the moment it's actually driven from the local endpoint's perspective. Note that I haven't renamed ar-transport.c to transport_object.c as the intention is to delete it when the rxrpc_transport struct is excised. The only file that actually has its contents changed is net/rxrpc/Makefile. net/rxrpc/ar-internal.h will need its section marker comments updating, but I'll do that in a separate patch to make it easier for git to follow the history across the rename. I may also want to rename ar-internal.h at some point - but that would mean updating all the #includes and I'd rather do that in a separate step. Signed-off-by: David Howells <dhowells@redhat.com.
2016-06-10rxrpc: Limit the listening backlogDavid Howells
Limit the socket incoming call backlog queue size so that a remote client can't pump in sufficient new calls that the server runs out of memory. Note that this is partially theoretical at the moment since whilst the number of calls is limited, the number of packets trying to set up new calls is not. This will be addressed in a later patch. If the caller of listen() specifies a backlog INT_MAX, then they get the current maximum; anything else greater than max_backlog or anything negative incurs EINVAL. The limit on the maximum queue size can be set by: echo N >/proc/sys/net/rxrpc/max_backlog where 4<=N<=32. Further, set the default backlog to 0, requiring listen() to be called before we start actually queueing new calls. Whilst this kind of is a change in the UAPI, the caller can't actually *accept* new calls anyway unless they've first called listen() to put the socket into the LISTENING state - thus the aforementioned new calls would otherwise just sit there, eating up kernel memory. (Note that sockets that don't have a non-zero service ID bound don't get incoming calls anyway.) Given that the default backlog is now 0, make the AFS filesystem call kernel_listen() to set the maximum backlog for itself. Possible improvements include: (1) Trimming a too-large backlog to max_backlog when listen is called. (2) Trimming the backlog value whenever the value is used so that changes to max_backlog are applied to an open socket automatically. Note that the AFS filesystem opens one socket and keeps it open for extended periods, so would miss out on changes to max_backlog. (3) Having a separate setting for the AFS filesystem. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10rxrpc: Trim line-terminal whitespaceDavid Howells
Trim line-terminal whitespace in net/rxrpc/ Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/sched/act_police.c net/sched/sch_drr.c net/sched/sch_hfsc.c net/sched/sch_prio.c net/sched/sch_red.c net/sched/sch_tbf.c In net-next the drop methods of the packet schedulers got removed, so the bug fixes to them in 'net' are irrelevant. A packet action unload crash fix conflicts with the addition of the new firstuse timestamp. Signed-off-by: David S. Miller <davem@davemloft.net>