1. 17 9月, 2016 1 次提交
  2. 14 9月, 2016 1 次提交
    • D
      rxrpc: Add IPv6 support · 75b54cb5
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      75b54cb5
  3. 08 9月, 2016 1 次提交
    • D
      rxrpc: Rewrite the data and ack handling code · 248f219c
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      248f219c
  4. 30 8月, 2016 2 次提交
  5. 15 6月, 2016 6 次提交
    • D
      rxrpc: Use the peer record to distribute network errors · f66d7490
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      f66d7490
    • D
      rxrpc: Do a little bit of tidying in the ICMP processing · fe77d5fc
      David Howells 提交于
      Do a little bit of tidying in the ICMP processing code.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      fe77d5fc
    • D
      rxrpc: Don't assume anything about the address in an ICMP packet · 1c1df86f
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      1c1df86f
    • D
      rxrpc: Break MTU determination from ICMP into its own function · 1a70c05b
      David Howells 提交于
      Break MTU determination from ICMP out into its own function to reduce the
      complexity of the error report handler.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      1a70c05b
    • D
      rxrpc: Rename rxrpc_UDP_error_report() to rxrpc_error_report() · abe89ef0
      David Howells 提交于
      Rename rxrpc_UDP_error_report() to rxrpc_error_report() as it might get
      called for something other than UDP.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      abe89ef0
    • D
      rxrpc: Rework peer object handling to use hash table and RCU · be6e6707
      David Howells 提交于
      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: NDavid Howells <dhowells@redhat.com>
      be6e6707
  6. 13 6月, 2016 1 次提交
    • D
      rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefix · 8c3e34a4
      David Howells 提交于
      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.
      8c3e34a4
  7. 05 3月, 2016 1 次提交
  8. 04 3月, 2016 2 次提交
  9. 09 3月, 2015 1 次提交
    • W
      ip: fix error queue empty skb handling · c247f053
      Willem de Bruijn 提交于
      When reading from the error queue, msg_name and msg_control are only
      populated for some errors. A new exception for empty timestamp skbs
      added a false positive on icmp errors without payload.
      
      `traceroute -M udpconn` only displayed gateways that return payload
      with the icmp error: the embedded network headers are pulled before
      sock_queue_err_skb, leaving an skb with skb->len == 0 otherwise.
      
      Fix this regression by refining when msg_name and msg_control
      branches are taken. The solutions for the two fields are independent.
      
      msg_name only makes sense for errors that configure serr->port and
      serr->addr_offset. Test the first instead of skb->len. This also fixes
      another issue. saddr could hold the wrong data, as serr->addr_offset
      is not initialized  in some code paths, pointing to the start of the
      network header. It is only valid when serr->port is set (non-zero).
      
      msg_control support differs between IPv4 and IPv6. IPv4 only honors
      requests for ICMP and timestamps with SOF_TIMESTAMPING_OPT_CMSG. The
      skb->len test can simply be removed, because skb->dev is also tested
      and never true for empty skbs. IPv6 honors requests for all errors
      aside from local errors and timestamps on empty skbs.
      
      In both cases, make the policy more explicit by moving this logic to
      a new function that decides whether to process msg_control and that
      optionally prepares the necessary fields in skb->cb[]. After this
      change, the IPv4 and IPv6 paths are more similar.
      
      The last case is rxrpc. Here, simply refine to only match timestamps.
      
      Fixes: 49ca0d8b ("net-timestamp: no-payload option")
      Reported-by: NJan Niehusmann <jan@gondor.com>
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      
      ----
      
      Changes
        v1->v2
        - fix local origin test inversion in ip6_datagram_support_cmsg
        - make v4 and v6 code paths more similar by introducing analogous
          ipv4_datagram_support_cmsg
        - fix compile bug in rxrpc
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c247f053
  10. 03 2月, 2015 1 次提交
    • W
      net-timestamp: no-payload option · 49ca0d8b
      Willem de Bruijn 提交于
      Add timestamping option SOF_TIMESTAMPING_OPT_TSONLY. For transmit
      timestamps, this loops timestamps on top of empty packets.
      
      Doing so reduces the pressure on SO_RCVBUF. Payload inspection and
      cmsg reception (aside from timestamps) are no longer possible. This
      works together with a follow on patch that allows administrators to
      only allow tx timestamping if it does not loop payload or metadata.
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      
      ----
      
      Changes (rfc -> v1)
        - add documentation
        - remove unnecessary skb->len test (thanks to Richard Cochran)
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      49ca0d8b
  11. 02 9月, 2014 1 次提交
    • W
      sock: deduplicate errqueue dequeue · 364a9e93
      Willem de Bruijn 提交于
      sk->sk_error_queue is dequeued in four locations. All share the
      exact same logic. Deduplicate.
      
      Also collapse the two critical sections for dequeue (at the top of
      the recv handler) and signal (at the bottom).
      
      This moves signal generation for the next packet forward, which should
      be harmless.
      
      It also changes the behavior if the recv handler exits early with an
      error. Previously, a signal for follow-up packets on the errqueue
      would then not be scheduled. The new behavior, to always signal, is
      arguably a bug fix.
      
      For rxrpc, the change causes the same function to be called repeatedly
      for each queued packet (because the recv handler == sk_error_report).
      It is likely that all packets will fail for the same reason (e.g.,
      memory exhaustion).
      
      This code runs without sk_lock held, so it is not safe to trust that
      sk->sk_err is immutable inbetween releasing q->lock and the subsequent
      test. Introduce int err just to avoid this potential race.
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      364a9e93
  12. 27 2月, 2014 1 次提交
    • D
      af_rxrpc: Fix UDP MTU calculation from ICMP_FRAG_NEEDED · 6c9a2d32
      David Howells 提交于
      AF_RXRPC sends UDP packets with the "Don't Fragment" bit set in an attempt to
      determine the maximum packet size between the local socket and the peer by
      invoking the generation of ICMP_FRAG_NEEDED packets.
      
      Once a packet is sent with the "Don't Fragment" bit set, it is then
      inconvenient to break it up as that requires recalculating all the rxrpc serial
      and sequence numbers and reencrypting all the fragments, so we switch off the
      "Don't Fragment" service temporarily and send the bounced packet again.  Future
      packets then use the new MTU.
      
      That's all fine.  The problem lies in rxrpc_UDP_error_report() where the code
      that deals with ICMP_FRAG_NEEDED packets lives.  Packets of this type have a
      field (ee_info) to indicate the maximum packet size at the reporting node - but
      sometimes ee_info isn't filled in and is just left as 0 and the code must allow
      for this.
      
      When ee_info is 0, the code should take the MTU size we're currently using and
      reduce it for the next packet we want to send.  However, it takes ee_info
      (which is known to be 0) and tries to reduce that instead.
      
      This was discovered by Coverity.
      Reported-by: NDave Jones <davej@redhat.com>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      6c9a2d32
  13. 11 6月, 2012 1 次提交
    • D
      ipv4: Kill ip_rt_frag_needed(). · 46517008
      David S. Miller 提交于
      There is zero point to this function.
      
      It's only real substance is to perform an extremely outdated BSD4.2
      ICMP check, which we can safely remove.  If you really have a MTU
      limited link being routed by a BSD4.2 derived system, here's a nickel
      go buy yourself a real router.
      
      The other actions of ip_rt_frag_needed(), checking and conditionally
      updating the peer, are done by the per-protocol handlers of the ICMP
      event.
      
      TCP, UDP, et al. have a handler which will receive this event and
      transmit it back into the associated route via dst_ops->update_pmtu().
      
      This simplification is important, because it eliminates the one place
      where we do not have a proper route context in which to make an
      inetpeer lookup.
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      46517008
  14. 20 5月, 2011 1 次提交
  15. 31 10月, 2008 1 次提交
  16. 05 5月, 2007 1 次提交
    • D
      [AF_RXRPC]: Sort out MTU handling. · 224711df
      David Howells 提交于
      Sort out the MTU determination and handling in AF_RXRPC:
      
       (1) If it's present, parse the additional information supplied by the peer at
           the end of the ACK packet (struct ackinfo) to determine the MTU sizes
           that peer is willing to support.
      
       (2) Initialise the MTU size to that peer from the kernel's routing records.
      
       (3) Send ACKs rather than ACKALLs as the former carry the additional info,
           and the latter do not.
      
       (4) Declare the interface MTU size in outgoing ACKs as a maximum amount of
           data that can be stuffed into an RxRPC packet without it having to be
           fragmented to come in this computer's NIC.
      
       (5) If sendmsg() is given MSG_MORE then it should allocate an skb of the
           maximum size rather than one just big enough for the data it's got left
           to process on the theory that there is more data to come that it can
           append to that packet.
      
           This means, for example, that if AFS does a large StoreData op, all the
           packets barring the last will be filled to the maximum unfragmented size.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      224711df
  17. 27 4月, 2007 2 次提交
    • D
      [AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use · 651350d1
      David Howells 提交于
      Add an interface to the AF_RXRPC module so that the AFS filesystem module can
      more easily make use of the services available.  AFS still opens a socket but
      then uses the action functions in lieu of sendmsg() and registers an intercept
      functions to grab messages before they're queued on the socket Rx queue.
      
      This permits AFS (or whatever) to:
      
       (1) Avoid the overhead of using the recvmsg() call.
      
       (2) Use different keys directly on individual client calls on one socket
           rather than having to open a whole slew of sockets, one for each key it
           might want to use.
      
       (3) Avoid calling request_key() at the point of issue of a call or opening of
           a socket.  This is done instead by AFS at the point of open(), unlink() or
           other VFS operation and the key handed through.
      
       (4) Request the use of something other than GFP_KERNEL to allocate memory.
      
      Furthermore:
      
       (*) The socket buffer markings used by RxRPC are made available for AFS so
           that it can interpret the cooked RxRPC messages itself.
      
       (*) rxgen (un)marshalling abort codes are made available.
      
      
      The following documentation for the kernel interface is added to
      Documentation/networking/rxrpc.txt:
      
      =========================
      AF_RXRPC KERNEL INTERFACE
      =========================
      
      The AF_RXRPC module also provides an interface for use by in-kernel utilities
      such as the AFS filesystem.  This permits such a utility to:
      
       (1) Use different keys directly on individual client calls on one socket
           rather than having to open a whole slew of sockets, one for each key it
           might want to use.
      
       (2) Avoid having RxRPC call request_key() at the point of issue of a call or
           opening of a socket.  Instead the utility is responsible for requesting a
           key at the appropriate point.  AFS, for instance, would do this during VFS
           operations such as open() or unlink().  The key is then handed through
           when the call is initiated.
      
       (3) Request the use of something other than GFP_KERNEL to allocate memory.
      
       (4) Avoid the overhead of using the recvmsg() call.  RxRPC messages can be
           intercepted before they get put into the socket Rx queue and the socket
           buffers manipulated directly.
      
      To use the RxRPC facility, a kernel utility must still open an AF_RXRPC socket,
      bind an addess as appropriate and listen if it's to be a server socket, but
      then it passes this to the kernel interface functions.
      
      The kernel interface functions are as follows:
      
       (*) Begin a new client call.
      
      	struct rxrpc_call *
      	rxrpc_kernel_begin_call(struct socket *sock,
      				struct sockaddr_rxrpc *srx,
      				struct key *key,
      				unsigned long user_call_ID,
      				gfp_t gfp);
      
           This allocates the infrastructure to make a new RxRPC call and assigns
           call and connection numbers.  The call will be made on the UDP port that
           the socket is bound to.  The call will go to the destination address of a
           connected client socket unless an alternative is supplied (srx is
           non-NULL).
      
           If a key is supplied then this will be used to secure the call instead of
           the key bound to the socket with the RXRPC_SECURITY_KEY sockopt.  Calls
           secured in this way will still share connections if at all possible.
      
           The user_call_ID is equivalent to that supplied to sendmsg() in the
           control data buffer.  It is entirely feasible to use this to point to a
           kernel data structure.
      
           If this function is successful, an opaque reference to the RxRPC call is
           returned.  The caller now holds a reference on this and it must be
           properly ended.
      
       (*) End a client call.
      
      	void rxrpc_kernel_end_call(struct rxrpc_call *call);
      
           This is used to end a previously begun call.  The user_call_ID is expunged
           from AF_RXRPC's knowledge and will not be seen again in association with
           the specified call.
      
       (*) Send data through a call.
      
      	int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg,
      				   size_t len);
      
           This is used to supply either the request part of a client call or the
           reply part of a server call.  msg.msg_iovlen and msg.msg_iov specify the
           data buffers to be used.  msg_iov may not be NULL and must point
           exclusively to in-kernel virtual addresses.  msg.msg_flags may be given
           MSG_MORE if there will be subsequent data sends for this call.
      
           The msg must not specify a destination address, control data or any flags
           other than MSG_MORE.  len is the total amount of data to transmit.
      
       (*) Abort a call.
      
      	void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code);
      
           This is used to abort a call if it's still in an abortable state.  The
           abort code specified will be placed in the ABORT message sent.
      
       (*) Intercept received RxRPC messages.
      
      	typedef void (*rxrpc_interceptor_t)(struct sock *sk,
      					    unsigned long user_call_ID,
      					    struct sk_buff *skb);
      
      	void
      	rxrpc_kernel_intercept_rx_messages(struct socket *sock,
      					   rxrpc_interceptor_t interceptor);
      
           This installs an interceptor function on the specified AF_RXRPC socket.
           All messages that would otherwise wind up in the socket's Rx queue are
           then diverted to this function.  Note that care must be taken to process
           the messages in the right order to maintain DATA message sequentiality.
      
           The interceptor function itself is provided with the address of the socket
           and handling the incoming message, the ID assigned by the kernel utility
           to the call and the socket buffer containing the message.
      
           The skb->mark field indicates the type of message:
      
      	MARK				MEANING
      	===============================	=======================================
      	RXRPC_SKB_MARK_DATA		Data message
      	RXRPC_SKB_MARK_FINAL_ACK	Final ACK received for an incoming call
      	RXRPC_SKB_MARK_BUSY		Client call rejected as server busy
      	RXRPC_SKB_MARK_REMOTE_ABORT	Call aborted by peer
      	RXRPC_SKB_MARK_NET_ERROR	Network error detected
      	RXRPC_SKB_MARK_LOCAL_ERROR	Local error encountered
      	RXRPC_SKB_MARK_NEW_CALL		New incoming call awaiting acceptance
      
           The remote abort message can be probed with rxrpc_kernel_get_abort_code().
           The two error messages can be probed with rxrpc_kernel_get_error_number().
           A new call can be accepted with rxrpc_kernel_accept_call().
      
           Data messages can have their contents extracted with the usual bunch of
           socket buffer manipulation functions.  A data message can be determined to
           be the last one in a sequence with rxrpc_kernel_is_data_last().  When a
           data message has been used up, rxrpc_kernel_data_delivered() should be
           called on it..
      
           Non-data messages should be handled to rxrpc_kernel_free_skb() to dispose
           of.  It is possible to get extra refs on all types of message for later
           freeing, but this may pin the state of a call until the message is finally
           freed.
      
       (*) Accept an incoming call.
      
      	struct rxrpc_call *
      	rxrpc_kernel_accept_call(struct socket *sock,
      				 unsigned long user_call_ID);
      
           This is used to accept an incoming call and to assign it a call ID.  This
           function is similar to rxrpc_kernel_begin_call() and calls accepted must
           be ended in the same way.
      
           If this function is successful, an opaque reference to the RxRPC call is
           returned.  The caller now holds a reference on this and it must be
           properly ended.
      
       (*) Reject an incoming call.
      
      	int rxrpc_kernel_reject_call(struct socket *sock);
      
           This is used to reject the first incoming call on the socket's queue with
           a BUSY message.  -ENODATA is returned if there were no incoming calls.
           Other errors may be returned if the call had been aborted (-ECONNABORTED)
           or had timed out (-ETIME).
      
       (*) Record the delivery of a data message and free it.
      
      	void rxrpc_kernel_data_delivered(struct sk_buff *skb);
      
           This is used to record a data message as having been delivered and to
           update the ACK state for the call.  The socket buffer will be freed.
      
       (*) Free a message.
      
      	void rxrpc_kernel_free_skb(struct sk_buff *skb);
      
           This is used to free a non-DATA socket buffer intercepted from an AF_RXRPC
           socket.
      
       (*) Determine if a data message is the last one on a call.
      
      	bool rxrpc_kernel_is_data_last(struct sk_buff *skb);
      
           This is used to determine if a socket buffer holds the last data message
           to be received for a call (true will be returned if it does, false
           if not).
      
           The data message will be part of the reply on a client call and the
           request on an incoming call.  In the latter case there will be more
           messages, but in the former case there will not.
      
       (*) Get the abort code from an abort message.
      
      	u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb);
      
           This is used to extract the abort code from a remote abort message.
      
       (*) Get the error number from a local or network error message.
      
      	int rxrpc_kernel_get_error_number(struct sk_buff *skb);
      
           This is used to extract the error number from a message indicating either
           a local error occurred or a network error occurred.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      651350d1
    • D
      [AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both · 17926a79
      David Howells 提交于
      Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
      answers to AFS clients.  KerberosIV security is fully supported.  The patches
      and some example test programs can be found in:
      
      	http://people.redhat.com/~dhowells/rxrpc/
      
      This will eventually replace the old implementation of kernel-only RxRPC
      currently resident in net/rxrpc/.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      17926a79