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* rxrpc: Make IPv6 support conditional on CONFIG_IPV6David Howells2016-09-178-2/+34
| | | | | | | | | | | | | | Add CONFIG_AF_RXRPC_IPV6 and make the IPv6 support code conditional on it. This is then made conditional on CONFIG_IPV6. Without this, the following can be seen: net/built-in.o: In function `rxrpc_init_peer': >> peer_object.c:(.text+0x18c3c8): undefined reference to `ip6_route_output_flags' Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Add IPv6 supportDavid Howells2016-09-137-83/+154
| | | | | | | | | | | | | | | | | | | Add IPv6 support to AF_RXRPC. With this, AF_RXRPC sockets can be created: service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET6); instead of: service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET); The AFS filesystem doesn't support IPv6 at the moment, though, since that requires upgrades to some of the RPC calls. Note that a good portion of this patch is replacing "%pI4:%u" in print statements with "%pISpc" which is able to handle both protocols and print the port. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use rxrpc_extract_addr_from_skb() rather than doing this manuallyDavid Howells2016-09-132-34/+11
| | | | | | | | | There are two places that want to transmit a packet in response to one just received and manually pick the address to reply to out of the sk_buff. Make them use rxrpc_extract_addr_from_skb() instead so that IPv6 is handled automatically. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Don't specify protocol to when creating transport socketDavid Howells2016-09-131-2/+2
| | | | | | | Pass 0 as the protocol argument when creating the transport socket rather than IPPROTO_UDP. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Create an address for sendmsg() to bind unbound socket withDavid Howells2016-09-131-0/+12
| | | | | | | | | | | | Create an address for sendmsg() to bind unbound socket with rather than using a completely blank address otherwise the transport socket creation will fail because it will try to use address family 0. We use the address family specified in the protocol argument when the AF_RXRPC socket was created and SOCK_DGRAM as the default. For anything else, bind() must be used. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Correctly initialise, limit and transmit call->rx_winsizeDavid Howells2016-09-136-13/+26
| | | | | | | | | | | | | | call->rx_winsize should be initialised to the sysctl setting and the sysctl setting should be limited to the maximum we want to permit. Further, we need to place this in the ACK info instead of the sysctl setting. Furthermore, discard the idea of accepting the subpackets of a jumbo packet that lie beyond the receive window when the first packet of the jumbo is within the window. Just discard the excess subpackets instead. This allows the receive window to be opened up right to the buffer size less one for the dead slot. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix prealloc refcountingDavid Howells2016-09-133-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The preallocated call buffer holds a ref on the calls within that buffer. The ref was being released in the wrong place - it worked okay for incoming calls to the AFS cache manager service, but doesn't work right for incoming calls to a userspace service. Instead of releasing an extra ref service calls in rxrpc_release_call(), the ref needs to be released during the acceptance/rejectance process. To this end: (1) The prealloc ref is now normally released during rxrpc_new_incoming_call(). (2) For preallocated kernel API calls, the kernel API's ref needs to be released when the call is discarded on socket close. (3) We shouldn't take a second ref in rxrpc_accept_call(). (4) rxrpc_recvmsg_new_call() needs to get a ref of its own when it adds the call to the to_be_accepted socket queue. In doing (4) above, we would prefer not to put the call's refcount down to 0 as that entails doing cleanup in softirq context, but it's unlikely as there are several refs held elsewhere, at least one of which must be put by someone in process context calling rxrpc_release_call(). However, it's not a problem if we do have to do that. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Adjust the call ref tracepoint to show kernel API refsDavid Howells2016-09-134-2/+7
| | | | | | | | | | | Adjust the call ref tracepoint to show references held on a call by the kernel API separately as much as possible and add an additional trace to at the allocation point from the preallocation buffer for an incoming call. Note that this doesn't show the allocation of a client call for the kernel separately at the moment. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Allow tx_winsize to grow in response to an ACKDavid Howells2016-09-131-3/+5
| | | | | | | Allow tx_winsize to grow when the ACK info packet shows a larger receive window at the other end rather than only permitting it to shrink. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use skb->len not skb->data_lenDavid Howells2016-09-131-4/+4
| | | | | | | | | | | | | skb->len should be used rather than skb->data_len when referring to the amount of data in a packet. This will only cause a malfunction in the following cases: (1) We receive a jumbo packet (validation and splitting both are wrong). (2) We see if there's extra ACK info in an ACK packet (we think it's not there and just ignore it). Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add missing unlock in rxrpc_call_accept()David Howells2016-09-131-3/+5
| | | | | | | Add a missing unlock in rxrpc_call_accept() in the path taken if there's no call to wake up. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Requeue call for recvmsg if more dataDavid Howells2016-09-131-0/+4
| | | | | | | | | | | | | | rxrpc_recvmsg() needs to make sure that the call it has just been processing gets requeued for further attention if the buffer has been filled and there's more data to be consumed. The softirq producer only queues the call and wakes the socket if it fills the first slot in the window, so userspace might end up sleeping forever otherwise, despite there being data available. This is not a problem provided the userspace buffer is big enough or it empties the buffer completely before more data comes in. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: The IDLE ACK packet should use rxrpc_idle_ack_delayDavid Howells2016-09-131-1/+1
| | | | | | | The IDLE ACK packet should use the rxrpc_idle_ack_delay setting when the timer is set for it. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add missing wakeup on Tx window rotationDavid Howells2016-09-131-0/+2
| | | | | | | | | | | | We need to wake up the sender when Tx window rotation due to an incoming ACK makes space in the buffer otherwise the sender is liable to just hang endlessly. This problem isn't noticeable if the Tx phase transfers no more than will fit in a single window or the Tx window rotates fast enough that it doesn't get full. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Make sure we initialise the peer hash keyDavid Howells2016-09-131-1/+1
| | | | | | | | | Peer records created for incoming connections weren't getting their hash key set. This meant that incoming calls wouldn't see more than one DATA packet - which is not a problem for AFS CM calls with small request data blobs. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Rewrite the data and ack handling codeDavid Howells2016-09-0821-3286/+1983
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Preallocate peers, conns and calls for incoming service requestsDavid Howells2016-09-088-10/+315
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible for the data_ready handler called from the UDP transport socket to completely instantiate an rxrpc_call structure and make it immediately live by preallocating all the memory it might need. The idea is to cut out the background thread usage as much as possible. [Note that the preallocated structs are not actually used in this patch - that will be done in a future patch.] If insufficient resources are available in the preallocation buffers, it will be possible to discard the DATA packet in the data_ready handler or schedule a BUSY packet without the need to schedule an attempt at allocation in a background thread. To this end: (1) Preallocate rxrpc_peer, rxrpc_connection and rxrpc_call structs to a maximum number each of the listen backlog size. The backlog size is limited to a maxmimum of 32. Only this many of each can be in the preallocation buffer. (2) For userspace sockets, the preallocation is charged initially by listen() and will be recharged by accepting or rejecting pending new incoming calls. (3) For kernel services {,re,dis}charging of the preallocation buffers is handled manually. Two notifier callbacks have to be provided before kernel_listen() is invoked: (a) An indication that a new call has been instantiated. This can be used to trigger background recharging. (b) An indication that a call is being discarded. This is used when the socket is being released. A function, rxrpc_kernel_charge_accept() is called by the kernel service to preallocate a single call. It should be passed the user ID to be used for that call and a callback to associate the rxrpc call with the kernel service's side of the ID. (4) Discard the preallocation when the socket is closed. (5) Temporarily bump the refcount on the call allocated in rxrpc_incoming_call() so that rxrpc_release_call() can ditch the preallocation ref on service calls unconditionally. This will no longer be necessary once the preallocation is used. Note that this does not yet control the number of active service calls on a client - that will come in a later patch. A future development would be to provide a setsockopt() call that allows a userspace server to manually charge the preallocation buffer. This would allow user call IDs to be provided in advance and the awkward manual accept stage to be bypassed. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add tracepoints to record received packets and end of data_readyDavid Howells2016-09-081-2/+6
| | | | | | | | | | | Add two tracepoints: (1) Record the RxRPC protocol header of packets retrieved from the UDP socket by the data_ready handler. (2) Record the outcome of the data_ready handler. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Remove skb_count from struct rxrpc_callDavid Howells2016-09-082-23/+12
| | | | | | | Remove the sk_buff count from the rxrpc_call struct as it's less useful once we stop queueing sk_buffs. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Convert rxrpc_local::services to an hlistDavid Howells2016-09-085-11/+11
| | | | | | | Convert the rxrpc_local::services list to an hlist so that it can be accessed under RCU conditions more readily. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix ASSERTCMP and ASSERTIFCMP to handle signed valuesDavid Howells2016-09-081-11/+13
| | | | | | | | | | | | Fix ASSERTCMP and ASSERTIFCMP to be able to handle signed values by casting both parameters to the type of the first before comparing. Without this, both values are cast to unsigned long, which means that checks for values less than zero don't work. The downside of this is that the state enum values in struct rxrpc_call and struct rxrpc_connection can't be bitfields as __typeof__ can't handle them. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add tracepoint for working out where aborts happenDavid Howells2016-09-078-90/+91
| | | | | | | | | | | Add a tracepoint for working out where local aborts happen. Each tracepoint call is labelled with a 3-letter code so that they can be distinguished - and the DATA sequence number is added too where available. rxrpc_kernel_abort_call() also takes a 3-letter code so that AFS can indicate the circumstances when it aborts a call. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix returns of call completion helpersDavid Howells2016-09-071-5/+8
| | | | | | | | | | rxrpc_set_call_completion() returns bool, not int, so the ret variable should match this. rxrpc_call_completed() and __rxrpc_call_completed() should return the value of rxrpc_set_call_completion(). Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Calls shouldn't hold socket refsDavid Howells2016-09-0711-279/+303
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rxrpc calls shouldn't hold refs on the sock struct. This was done so that the socket wouldn't go away whilst the call was in progress, such that the call could reach the socket's queues. However, we can mark the socket as requiring an RCU release and rely on the RCU read lock. To make this work, we do: (1) rxrpc_release_call() removes the call's call user ID. This is now only called from socket operations and not from the call processor: rxrpc_accept_call() / rxrpc_kernel_accept_call() rxrpc_reject_call() / rxrpc_kernel_reject_call() rxrpc_kernel_end_call() rxrpc_release_calls_on_socket() rxrpc_recvmsg() Though it is also called in the cleanup path of rxrpc_accept_incoming_call() before we assign a user ID. (2) Pass the socket pointer into rxrpc_release_call() rather than getting it from the call so that we can get rid of uninitialised calls. (3) Fix call processor queueing to pass a ref to the work queue and to release that ref at the end of the processor function (or to pass it back to the work queue if we have to requeue). (4) Skip out of the call processor function asap if the call is complete and don't requeue it if the call is complete. (5) Clean up the call immediately that the refcount reaches 0 rather than trying to defer it. Actual deallocation is deferred to RCU, however. (6) Don't hold socket refs for allocated calls. (7) Use the RCU read lock when queueing a message on a socket and treat the call's socket pointer according to RCU rules and check it for NULL. We also need to use the RCU read lock when viewing a call through procfs. (8) Transmit the final ACK/ABORT to a client call in rxrpc_release_call() if this hasn't been done yet so that we can then disconnect the call. Once the call is disconnected, it won't have any access to the connection struct and the UDP socket for the call work processor to be able to send the ACK. Terminal retransmission will be handled by the connection processor. (9) Release all calls immediately on the closing of a socket rather than trying to defer this. Incomplete calls will be aborted. The call refcount model is much simplified. Refs are held on the call by: (1) A socket's user ID tree. (2) A socket's incoming call secureq and acceptq. (3) A kernel service that has a call in progress. (4) A queued call work processor. We have to take care to put any call that we failed to queue. (5) sk_buffs on a socket's receive queue. A future patch will get rid of this. Whilst we're at it, we can do: (1) Get rid of the RXRPC_CALL_EV_RELEASE event. Release is now done entirely from the socket routines and never from the call's processor. (2) Get rid of the RXRPC_CALL_DEAD state. Calls now end in the RXRPC_CALL_COMPLETE state. (3) Get rid of the rxrpc_call::destroyer work item. Calls are now torn down when their refcount reaches 0 and then handed over to RCU for final cleanup. (4) Get rid of the rxrpc_call::deadspan timer. Calls are cleaned up immediately they're finished with and don't hang around. Post-completion retransmission is handled by the connection processor once the call is disconnected. (5) Get rid of the dead call expiry setting as there's no longer a timer to set. (6) rxrpc_destroy_all_calls() can just check that the call list is empty. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use rxrpc_is_service_call() rather than rxrpc_conn_is_service()David Howells2016-09-071-2/+2
| | | | | | | Use rxrpc_is_service_call() rather than rxrpc_conn_is_service() if the call is available just in case call->conn is NULL. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Pass the connection pointer to rxrpc_post_packet_to_call()David Howells2016-09-071-3/+4
| | | | | | | | | Pass the connection pointer to rxrpc_post_packet_to_call() as the call might get disconnected whilst we're looking at it, but the connection pointer determined by rxrpc_data_read() is guaranteed by RCU for the duration of the call. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Cache the security index in the rxrpc_call structDavid Howells2016-09-075-2/+7
| | | | | | | | Cache the security index in the rxrpc_call struct so that we can get at it even when the call has been disconnected and the connection pointer cleared. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use call->peer rather than call->conn->params.peerDavid Howells2016-09-071-3/+5
| | | | | | | | Use call->peer rather than call->conn->params.peer to avoid the possibility of call->conn being NULL and, whilst we're at it, check it for NULL before we access it. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Improve the call tracking tracepointDavid Howells2016-09-079-43/+76
| | | | | | | | | | | | | | | | | | | Improve the call tracking tracepoint by showing more differentiation between some of the put and get events, including: (1) Getting and putting refs for the socket call user ID tree. (2) Getting and putting refs for queueing and failing to queue the call processor work item. Note that these aren't necessarily used in this patch, but will be taken advantage of in future patches. An enum is added for the event subtype numbers rather than coding them directly as decimal numbers and a table of 3-letter strings is provided rather than a sequence of ?: operators. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Delete unused rxrpc_kernel_free_skb()David Howells2016-09-071-13/+0
| | | | | | Delete rxrpc_kernel_free_skb() as it's unused. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Whitespace cleanupDavid Howells2016-09-071-2/+1
| | | | | | Remove some whitespace. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc Move enum rxrpc_command to sendmsg.cDavid Howells2016-09-042-7/+7
| | | | | | Move enum rxrpc_command to sendmsg.c as it's now only used in that file. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Rearrange net/rxrpc/sendmsg.cDavid Howells2016-09-041-281/+277
| | | | | | | Rearrange net/rxrpc/sendmsg.c to be in a more logical order. This makes it easier to follow and eliminates forward declarations. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Split sendmsg from packet transmission codeDavid Howells2016-09-045-633/+657
| | | | | | | Split the sendmsg code from the packet transmission code (mostly to be found in output.c). Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Don't change the epochDavid Howells2016-09-041-24/+8
| | | | | | | It seems the local epoch should only be changed on boot, so remove the code that changes it for client connections. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Randomise epoch and starting client conn ID valuesDavid Howells2016-09-041-1/+8
| | | | | | | | | | Create a random epoch value rather than a time-based one on startup and set the top bit to indicate that this is the case. Also create a random starting client connection ID value. This will be incremented from here as new client connections are created. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: The client call state must be changed before attachment to connDavid Howells2016-09-042-2/+4
| | | | | | | | | | We must set the client call state to RXRPC_CALL_CLIENT_SEND_REQUEST before attaching the call to the connection struct, not after, as it's liable to receive errors and conn aborts as soon as the assignment is made - and these will cause its state to be changed outside of the initiating thread's control. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix uninitialised variable warningDavid Howells2016-09-021-3/+2
| | | | | | | | | | | Fix the following uninitialised variable warning: ../net/rxrpc/call_event.c: In function 'rxrpc_process_call': ../net/rxrpc/call_event.c:879:58: warning: 'error' may be used uninitialized in this function [-Wmaybe-uninitialized] _debug("post net error %d", error); ^ Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: fix undefined behavior in rxrpc_mark_call_releasedArnd Bergmann2016-09-021-1/+1
| | | | | | | | | | | | | | | | gcc -Wmaybe-initialized correctly points out a newly introduced bug through which we can end up calling rxrpc_queue_call() for a dead connection: net/rxrpc/call_object.c: In function 'rxrpc_mark_call_released': net/rxrpc/call_object.c:600:5: error: 'sched' may be used uninitialized in this function [-Werror=maybe-uninitialized] This sets the 'sched' variable to zero to restore the previous behavior. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Don't expose skbs to in-kernel users [ver #2]David Howells2016-09-019-61/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't expose skbs to in-kernel users, such as the AFS filesystem, but instead provide a notification hook the indicates that a call needs attention and another that indicates that there's a new call to be collected. This makes the following possibilities more achievable: (1) Call refcounting can be made simpler if skbs don't hold refs to calls. (2) skbs referring to non-data events will be able to be freed much sooner rather than being queued for AFS to pick up as rxrpc_kernel_recv_data will be able to consult the call state. (3) We can shortcut the receive phase when a call is remotely aborted because we don't have to go through all the packets to get to the one cancelling the operation. (4) It makes it easier to do encryption/decryption directly between AFS's buffers and sk_buffs. (5) Encryption/decryption can more easily be done in the AFS's thread contexts - usually that of the userspace process that issued a syscall - rather than in one of rxrpc's background threads on a workqueue. (6) AFS will be able to wait synchronously on a call inside AF_RXRPC. To make this work, the following interface function has been added: int rxrpc_kernel_recv_data( struct socket *sock, struct rxrpc_call *call, void *buffer, size_t bufsize, size_t *_offset, bool want_more, u32 *_abort_code); This is the recvmsg equivalent. It allows the caller to find out about the state of a specific call and to transfer received data into a buffer piecemeal. afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction logic between them. They don't wait synchronously yet because the socket lock needs to be dealt with. Five interface functions have been removed: rxrpc_kernel_is_data_last() rxrpc_kernel_get_abort_code() rxrpc_kernel_get_error_number() rxrpc_kernel_free_skb() rxrpc_kernel_data_consumed() As a temporary hack, sk_buffs going to an in-kernel call are queued on the rxrpc_call struct (->knlrecv_queue) rather than being handed over to the in-kernel user. To process the queue internally, a temporary function, temp_deliver_data() has been added. This will be replaced with common code between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a future patch. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Pass struct socket * to more rxrpc kernel interface functionsDavid Howells2016-08-302-11/+14
| | | | | | | | | | | | | | | | | | | Pass struct socket * to more rxrpc kernel interface functions. They should be starting from this rather than the socket pointer in the rxrpc_call struct if they need to access the socket. I have left: rxrpc_kernel_is_data_last() rxrpc_kernel_get_abort_code() rxrpc_kernel_get_error_number() rxrpc_kernel_free_skb() rxrpc_kernel_data_consumed() unmodified as they're all about to be removed (and, in any case, don't touch the socket). Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Use call->peer rather than going to the connectionDavid Howells2016-08-301-5/+5
| | | | | | | Use call->peer rather than call->conn->params.peer as call->conn may become NULL. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Provide a way for AFS to ask for the peer address of a callDavid Howells2016-08-301-0/+15
| | | | | | | | | | | | | | | | | Provide a function so that kernel users, such as AFS, can ask for the peer address of a call: void rxrpc_kernel_get_peer(struct rxrpc_call *call, struct sockaddr_rxrpc *_srx); In the future the kernel service won't get sk_buffs to look inside. Further, this allows us to hide any canonicalisation inside AF_RXRPC for when IPv6 support is added. Also propagate this through to afs_find_server() and issue a warning if we can't handle the address family yet. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Trace rxrpc_call usageDavid Howells2016-08-3011-34/+104
| | | | | | Add a trace event for debuging rxrpc_call struct usage. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Calls should only have one terminal stateDavid Howells2016-08-3012-184/+226
| | | | | | | | | | | Condense the terminal states of a call state machine to a single state, plus a separate completion type value. The value is then set, along with error and abort code values, only when the call is transitioned to the completion state. Helpers are provided to simplify this. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix a potential NULL-pointer deref in rxrpc_abort_callsDavid Howells2016-08-301-11/+15
| | | | | | | | The call pointer in a channel on a connection will be NULL if there's no active call on that channel. rxrpc_abort_calls() needs to check for this before trying to take the call's state_lock. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Improve management and caching of client connection objectsDavid Howells2016-08-248-157/+933
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Improve the management and caching of client rxrpc connection objects. From this point, client connections will be managed separately from service connections because AF_RXRPC controls the creation and re-use of client connections but doesn't have that luxury with service connections. Further, there will be limits on the numbers of client connections that may be live on a machine. No direct restriction will be placed on the number of client calls, excepting that each client connection can support a maximum of four concurrent calls. Note that, for a number of reasons, we don't want to simply discard a client connection as soon as the last call is apparently finished: (1) Security is negotiated per-connection and the context is then shared between all calls on that connection. The context can be negotiated again if the connection lapses, but that involves holding up calls whilst at least two packets are exchanged and various crypto bits are performed - so we'd ideally like to cache it for a little while at least. (2) If a packet goes astray, we will need to retransmit a final ACK or ABORT packet. To make this work, we need to keep around the connection details for a little while. (3) The locally held structures represent some amount of setup time, to be weighed against their occupation of memory when idle. To this end, the client connection cache is managed by a state machine on each connection. There are five states: (1) INACTIVE - The connection is not held in any list and may not have been exposed to the world. If it has been previously exposed, it was discarded from the idle list after expiring. (2) WAITING - The connection is waiting for the number of client conns to drop below the maximum capacity. Calls may be in progress upon it from when it was active and got culled. The connection is on the rxrpc_waiting_client_conns list which is kept in to-be-granted order. Culled conns with waiters go to the back of the queue just like new conns. (3) ACTIVE - The connection has at least one call in progress upon it, it may freely grant available channels to new calls and calls may be waiting on it for channels to become available. The connection is on the rxrpc_active_client_conns list which is kept in activation order for culling purposes. (4) CULLED - The connection got summarily culled to try and free up capacity. Calls currently in progress on the connection are allowed to continue, but new calls will have to wait. There can be no waiters in this state - the conn would have to go to the WAITING state instead. (5) IDLE - The connection has no calls in progress upon it and must have been exposed to the world (ie. the EXPOSED flag must be set). When it expires, the EXPOSED flag is cleared and the connection transitions to the INACTIVE state. The connection is on the rxrpc_idle_client_conns list which is kept in order of how soon they'll expire. A connection in the ACTIVE or CULLED state must have at least one active call upon it; if in the WAITING state it may have active calls upon it; other states may not have active calls. As long as a connection remains active and doesn't get culled, it may continue to process calls - even if there are connections on the wait queue. This simplifies things a bit and reduces the amount of checking we need do. There are a couple flags of relevance to the cache: (1) EXPOSED - The connection ID got exposed to the world. If this flag is set, an extra ref is added to the connection preventing it from being reaped when it has no calls outstanding. This flag is cleared and the ref dropped when a conn is discarded from the idle list. (2) DONT_REUSE - The connection should be discarded as soon as possible and should not be reused. This commit also provides a number of new settings: (*) /proc/net/rxrpc/max_client_conns The maximum number of live client connections. Above this number, new connections get added to the wait list and must wait for an active conn to be culled. Culled connections can be reused, but they will go to the back of the wait list and have to wait. (*) /proc/net/rxrpc/reap_client_conns If the number of desired connections exceeds the maximum above, the active connection list will be culled until there are only this many left in it. (*) /proc/net/rxrpc/idle_conn_expiry The normal expiry time for a client connection, provided there are fewer than reap_client_conns of them around. (*) /proc/net/rxrpc/idle_conn_fast_expiry The expedited expiry time, used when there are more than reap_client_conns of them around. Note that I combined the Tx wait queue with the channel grant wait queue to save space as only one of these should be in use at once. Note also that, for the moment, the service connection cache still uses the old connection management code. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Dup the main conn list for the proc interfaceDavid Howells2016-08-245-4/+11
| | | | | | | | | | | | | | | | | The main connection list is used for two independent purposes: primarily it is used to find connections to reap and secondarily it is used to list connections in procfs. Split the procfs list out from the reap list. This allows us to stop using the reap list for client connections when they acquire a separate management strategy from service collections. The client connections will not be on a management single list, and sometimes won't be on a management list at all. This doesn't leave them floating, however, as they will also be on an rb-tree rooted on the socket so that the socket can find them to dispatch calls. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Make /proc/net/rxrpc_calls saferDavid Howells2016-08-244-9/+26
| | | | | | | | | | Make /proc/net/rxrpc_calls safer by stashing a copy of the peer pointer in the rxrpc_call struct and checking in the show routine that the peer pointer, the socket pointer and the local pointer obtained from the socket pointer aren't NULL before we use them. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix conn-based retransmitDavid Howells2016-08-242-1/+2
| | | | | | | | | | | | | | | If a duplicate packet comes in for a call that has just completed on a connection's channel then there will be an oops in the data_ready handler because it tries to examine the connection struct via a call struct (which we don't have - the pointer is unset). Since the connection struct pointer is available to us, go direct instead. Also, the ACK packet to be retransmitted needs three octets of padding between the soft ack list and the ackinfo. Fixes: 18bfeba50dfd0c8ee420396f2570f16a0bdbd7de ("rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor") Signed-off-by: David Howells <dhowells@redhat.com>