1. 23 Sep, 2016 1 commit
    • David Howells's avatar
      rxrpc: Add tracepoint for ACK proposal · 9c7ad434
      David Howells authored
      Add a tracepoint to log proposed ACKs, including whether the proposal is
      used to update a pending ACK or is discarded in favour of an easlier,
      higher priority ACK.
      
      Whilst we're at it, get rid of the rxrpc_acks() function and access the
      name array directly.  We do, however, need to validate the ACK reason
      number given to trace_rxrpc_rx_ack() to make sure we don't overrun the
      array.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      9c7ad434
  2. 08 Sep, 2016 2 commits
    • David Howells's avatar
      rxrpc: Rewrite the data and ack handling code · 248f219c
      David Howells authored
      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: 's avatarDavid Howells <dhowells@redhat.com>
      248f219c
    • David Howells's avatar
      rxrpc: Update protocol definitions slightly · 18f1387c
      David Howells authored
      Update the protocol definitions in include/rxrpc/packet.h slightly:
      
       (1) Get rid of RXRPC_PROCESS_MAXCALLS as it's redundant (same as
           RXRPC_MAXCALLS).
      
       (2) In struct rxrpc_jumbo_header, put _rsvd in a union with a field called
           cksum to match struct rxrpc_wire_header.
      
       (3) Provide RXRPC_JUMBO_SUBPKTLEN which is the total of the amount of data
           in a non-terminal subpacket plus the following secondary header for
           the next packet included in the jumbo packet.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      18f1387c
  3. 04 Sep, 2016 1 commit
  4. 11 Apr, 2016 1 commit
  5. 04 Mar, 2016 2 commits
    • David Howells's avatar
      rxrpc: Be more selective about the types of received packets we accept · 351c1e64
      David Howells authored
      Currently, received RxRPC packets outside the range 1-13 are rejected.
      There are, however, holes in the range that should also be rejected - plus
      at least one type we don't yet support - so reject these also.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      351c1e64
    • David Howells's avatar
      rxrpc: Keep the skb private record of the Rx header in host byte order · 0d12f8a4
      David Howells authored
      Currently, a copy of the Rx packet header is copied into the the sk_buff
      private data so that we can advance the pointer into the buffer,
      potentially discarding the original.  At the moment, this copy is held in
      network byte order, but this means we're doing a lot of unnecessary
      translations.
      
      The reasons it was done this way are that we need the values in network
      byte order occasionally and we can use the copy, slightly modified, as part
      of an iov array when sending an ack or an abort packet.
      
      However, it seems more reasonable on review that it would be better kept in
      host byte order and that we make up a new header when we want to send
      another packet.
      
      To this end, rename the original header struct to rxrpc_wire_header (with
      BE fields) and institute a variant called rxrpc_host_header that has host
      order fields.  Change the struct in the sk_buff private data into an
      rxrpc_host_header and translate the values when filling it in.
      
      This further allows us to keep values kept in various structures in host
      byte order rather than network byte order and allows removal of some fields
      that are byteswapped duplicates.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      0d12f8a4
  6. 01 Apr, 2015 1 commit
    • David Howells's avatar
      RxRPC: Handle VERSION Rx protocol packets · 44ba0698
      David Howells authored
      Handle VERSION Rx protocol packets.  We should respond to a VERSION packet
      with a string indicating the Rx version.  This is a maximum of 64 characters
      and is padded out to 65 chars with NUL bytes.
      
      Note that other AFS clients use the version request as a NAT keepalive so we
      need to handle it rather than returning an abort.
      
      The standard formulation seems to be:
      
      	<project> <version> built <yyyy>-<mm>-<dd>
      
      for example:
      
      	" OpenAFS 1.6.2 built  2013-05-07 "
      
      (note the three extra spaces) as obtained with:
      
      	rxdebug grand.mit.edu -version
      
      from the openafs package.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      44ba0698
  7. 30 Aug, 2014 1 commit
  8. 26 Jul, 2011 1 commit
  9. 31 Mar, 2011 1 commit
  10. 03 Jun, 2010 1 commit
  11. 26 Apr, 2007 3 commits
    • David Howells's avatar
      [AF_RXRPC]: Delete the old RxRPC code. · 63b6be55
      David Howells authored
      Delete the old RxRPC code as it's now no longer used.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
      63b6be55
    • David Howells's avatar
      [AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use · 651350d1
      David Howells authored
      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: 's avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
      651350d1
    • David Howells's avatar
      [AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both · 17926a79
      David Howells authored
      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: 's avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
      17926a79
  12. 08 Oct, 2005 1 commit
  13. 05 Oct, 2005 1 commit
  14. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4