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2018-05-10rxrpc: Fix error reception on AF_INET6 socketsDavid Howells
AF_RXRPC tries to turn on IP_RECVERR and IP_MTU_DISCOVER on the UDP socket it just opened for communications with the outside world, regardless of the type of socket. Unfortunately, this doesn't work with an AF_INET6 socket. Fix this by turning on IPV6_RECVERR and IPV6_MTU_DISCOVER instead if the socket is of the AF_INET6 family. Without this, kAFS server and address rotation doesn't work correctly because the algorithm doesn't detect received network errors. Fixes: 75b54cb57ca3 ("rxrpc: Add IPv6 support") Signed-off-by: David Howells <dhowells@redhat.com>
2018-03-30rxrpc: Add a tracepoint to track rxrpc_local refcountingDavid Howells
Add a tracepoint to track reference counting on the rxrpc_local struct. Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05rxrpc: Permit multiple service bindingDavid Howells
Permit bind() to be called on an AF_RXRPC socket more than once (currently maximum twice) to bind multiple listening services to it. There are some restrictions: (1) All bind() calls involved must have a non-zero service ID. (2) The service IDs must all be different. (3) The rest of the address (notably the transport part) must be the same in all (a single UDP socket is shared). (4) This must be done before listen() or sendmsg() is called. This allows someone to connect to the service socket with different service IDs and lays the foundation for service upgrading. The service ID used by an incoming call can be extracted from the msg_name returned by recvmsg(). Signed-off-by: David Howells <dhowells@redhat.com>
2017-05-25rxrpc: Support network namespacingDavid Howells
Support network namespacing in AF_RXRPC with the following changes: (1) All the local endpoint, peer and call lists, locks, counters, etc. are moved into the per-namespace record. (2) All the connection tracking is moved into the per-namespace record with the exception of the client connection ID tree, which is kept global so that connection IDs are kept unique per-machine. (3) Each namespace gets its own epoch. This allows each network namespace to pretend to be a separate client machine. (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and the contents reflect the namespace. fs/afs/ should be okay with this patch as it explicitly requires the current net namespace to be init_net to permit a mount to proceed at the moment. It will, however, need updating so that cells, IP addresses and DNS records are per-namespace also. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-29rxrpc: Reduce the rxrpc_local::services list to a pointerDavid Howells
Reduce the rxrpc_local::services list to just a pointer as we don't permit multiple service endpoints to bind to a single transport endpoints (this is excluded by rxrpc_lookup_local()). The reason we don't allow this is that if you send a request to an AFS filesystem service, it will try to talk back to your cache manager on the port you sent from (this is how file change notifications are handled). To prevent someone from stealing your CM callbacks, we don't let AF_RXRPC sockets share a UDP socket if at least one of them has a service bound. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17rxrpc: Make IPv6 support conditional on CONFIG_IPV6David Howells
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>
2016-09-13rxrpc: Add IPv6 supportDavid Howells
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>
2016-09-13rxrpc: Don't specify protocol to when creating transport socketDavid Howells
Pass 0 as the protocol argument when creating the transport socket rather than IPPROTO_UDP. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08rxrpc: Rewrite the data and ack handling codeDavid Howells
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>
2016-09-08rxrpc: Convert rxrpc_local::services to an hlistDavid Howells
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>
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>
2016-06-22rxrpc: 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>
2016-06-15rxrpc: 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: 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>
2016-06-13rxrpc: 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.