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651350d10f
linux/net/rxrpc/ar-input.c
David Howells 651350d10f [AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use 
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: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-26 15:50:17 -07:00

798 lines
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/* RxRPC packet reception
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/errqueue.h>
#include <linux/udp.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/icmp.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
#include "ar-internal.h"
unsigned long rxrpc_ack_timeout = 1;
const char *rxrpc_pkts[] = {
"?00",
"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
"?09", "?10", "?11", "?12", "?13", "?14", "?15"
};
/*
* queue a packet for recvmsg to pass to userspace
* - the caller must hold a lock on call->lock
* - must not be called with interrupts disabled (sk_filter() disables BH's)
* - eats the packet whether successful or not
* - there must be just one reference to the packet, which the caller passes to
* this function
*/
int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
bool force, bool terminal)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_sock *rx = call->socket;
struct sock *sk;
int skb_len, ret;
_enter(",,%d,%d", force, terminal);
ASSERT(!irqs_disabled());
sp = rxrpc_skb(skb);
ASSERTCMP(sp->call, ==, call);
/* if we've already posted the terminal message for a call, then we
* don't post any more */
if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
_debug("already terminated");
ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
skb->destructor = NULL;
sp->call = NULL;
rxrpc_put_call(call);
rxrpc_free_skb(skb);
return 0;
}
sk = &rx->sk;
if (!force) {
/* cast skb->rcvbuf to unsigned... It's pointless, but
* reduces number of warnings when compiling with -W
* --ANK */
// ret = -ENOBUFS;
// if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
// (unsigned) sk->sk_rcvbuf)
// goto out;
ret = sk_filter(sk, skb);
if (ret < 0)
goto out;
}
spin_lock_bh(&sk->sk_receive_queue.lock);
if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
call->socket->sk.sk_state != RXRPC_CLOSE) {
skb->destructor = rxrpc_packet_destructor;
skb->dev = NULL;
skb->sk = sk;
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
if (terminal) {
_debug("<<<< TERMINAL MESSAGE >>>>");
set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
}
/* allow interception by a kernel service */
if (rx->interceptor) {
rx->interceptor(sk, call->user_call_ID, skb);
spin_unlock_bh(&sk->sk_receive_queue.lock);
} else {
/* Cache the SKB length before we tack it onto the
* receive queue. Once it is added it no longer
* belongs to us and may be freed by other threads of
* control pulling packets from the queue */
skb_len = skb->len;
_net("post skb %p", skb);
__skb_queue_tail(&sk->sk_receive_queue, skb);
spin_unlock_bh(&sk->sk_receive_queue.lock);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk, skb_len);
}
skb = NULL;
} else {
spin_unlock_bh(&sk->sk_receive_queue.lock);
}
ret = 0;
out:
/* release the socket buffer */
if (skb) {
skb->destructor = NULL;
sp->call = NULL;
rxrpc_put_call(call);
rxrpc_free_skb(skb);
}
_leave(" = %d", ret);
return ret;
}
/*
* process a DATA packet, posting the packet to the appropriate queue
* - eats the packet if successful
*/
static int rxrpc_fast_process_data(struct rxrpc_call *call,
struct sk_buff *skb, u32 seq)
{
struct rxrpc_skb_priv *sp;
bool terminal;
int ret, ackbit, ack;
_enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
sp = rxrpc_skb(skb);
ASSERTCMP(sp->call, ==, NULL);
spin_lock(&call->lock);
if (call->state > RXRPC_CALL_COMPLETE)
goto discard;
ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
if (seq < call->rx_data_post) {
_debug("dup #%u [-%u]", seq, call->rx_data_post);
ack = RXRPC_ACK_DUPLICATE;
ret = -ENOBUFS;
goto discard_and_ack;
}
/* we may already have the packet in the out of sequence queue */
ackbit = seq - (call->rx_data_eaten + 1);
ASSERTCMP(ackbit, >=, 0);
if (__test_and_set_bit(ackbit, &call->ackr_window)) {
_debug("dup oos #%u [%u,%u]",
seq, call->rx_data_eaten, call->rx_data_post);
ack = RXRPC_ACK_DUPLICATE;
goto discard_and_ack;
}
if (seq >= call->ackr_win_top) {
_debug("exceed #%u [%u]", seq, call->ackr_win_top);
__clear_bit(ackbit, &call->ackr_window);
ack = RXRPC_ACK_EXCEEDS_WINDOW;
goto discard_and_ack;
}
if (seq == call->rx_data_expect) {
clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
call->rx_data_expect++;
} else if (seq > call->rx_data_expect) {
_debug("oos #%u [%u]", seq, call->rx_data_expect);
call->rx_data_expect = seq + 1;
if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
ack = RXRPC_ACK_OUT_OF_SEQUENCE;
goto enqueue_and_ack;
}
goto enqueue_packet;
}
if (seq != call->rx_data_post) {
_debug("ahead #%u [%u]", seq, call->rx_data_post);
goto enqueue_packet;
}
if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
goto protocol_error;
/* if the packet need security things doing to it, then it goes down
* the slow path */
if (call->conn->security)
goto enqueue_packet;
sp->call = call;
rxrpc_get_call(call);
terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
!(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
if (ret < 0) {
if (ret == -ENOMEM || ret == -ENOBUFS) {
__clear_bit(ackbit, &call->ackr_window);
ack = RXRPC_ACK_NOSPACE;
goto discard_and_ack;
}
goto out;
}
skb = NULL;
_debug("post #%u", seq);
ASSERTCMP(call->rx_data_post, ==, seq);
call->rx_data_post++;
if (sp->hdr.flags & RXRPC_LAST_PACKET)
set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
/* if we've reached an out of sequence packet then we need to drain
* that queue into the socket Rx queue now */
if (call->rx_data_post == call->rx_first_oos) {
_debug("drain rx oos now");
read_lock(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE &&
!test_and_set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events))
rxrpc_queue_call(call);
read_unlock(&call->state_lock);
}
spin_unlock(&call->lock);
atomic_inc(&call->ackr_not_idle);
rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
_leave(" = 0 [posted]");
return 0;
protocol_error:
ret = -EBADMSG;
out:
spin_unlock(&call->lock);
_leave(" = %d", ret);
return ret;
discard_and_ack:
_debug("discard and ACK packet %p", skb);
__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
discard:
spin_unlock(&call->lock);
rxrpc_free_skb(skb);
_leave(" = 0 [discarded]");
return 0;
enqueue_and_ack:
__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
enqueue_packet:
_net("defer skb %p", skb);
spin_unlock(&call->lock);
skb_queue_tail(&call->rx_queue, skb);
atomic_inc(&call->ackr_not_idle);
read_lock(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD)
rxrpc_queue_call(call);
read_unlock(&call->state_lock);
_leave(" = 0 [queued]");
return 0;
}
/*
* assume an implicit ACKALL of the transmission phase of a client socket upon
* reception of the first reply packet
*/
static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
{
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
call->acks_latest = serial;
_debug("implicit ACKALL %%%u", call->acks_latest);
set_bit(RXRPC_CALL_RCVD_ACKALL, &call->events);
write_unlock_bh(&call->state_lock);
if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
clear_bit(RXRPC_CALL_RESEND, &call->events);
clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
}
break;
default:
write_unlock_bh(&call->state_lock);
break;
}
}
/*
* post an incoming packet to the nominated call to deal with
* - must get rid of the sk_buff, either by freeing it or by queuing it
*/
void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
__be32 _abort_code;
u32 serial, hi_serial, seq, abort_code;
_enter("%p,%p", call, skb);
ASSERT(!irqs_disabled());
#if 0 // INJECT RX ERROR
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
static int skip = 0;
if (++skip == 3) {
printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
skip = 0;
goto free_packet;
}
}
#endif
/* track the latest serial number on this connection for ACK packet
* information */
serial = ntohl(sp->hdr.serial);
hi_serial = atomic_read(&call->conn->hi_serial);
while (serial > hi_serial)
hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
serial);
/* request ACK generation for any ACK or DATA packet that requests
* it */
if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
_proto("ACK Requested on %%%u", serial);
rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial,
!(sp->hdr.flags & RXRPC_MORE_PACKETS));
}
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_ABORT:
_debug("abort");
if (skb_copy_bits(skb, 0, &_abort_code,
sizeof(_abort_code)) < 0)
goto protocol_error;
abort_code = ntohl(_abort_code);
_proto("Rx ABORT %%%u { %x }", serial, abort_code);
write_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_REMOTELY_ABORTED;
call->abort_code = abort_code;
set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
rxrpc_queue_call(call);
}
goto free_packet_unlock;
case RXRPC_PACKET_TYPE_BUSY:
_proto("Rx BUSY %%%u", serial);
if (call->conn->out_clientflag)
goto protocol_error;
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
call->state = RXRPC_CALL_SERVER_BUSY;
set_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
rxrpc_queue_call(call);
case RXRPC_CALL_SERVER_BUSY:
goto free_packet_unlock;
default:
goto protocol_error_locked;
}
default:
_proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], serial);
goto protocol_error;
case RXRPC_PACKET_TYPE_DATA:
seq = ntohl(sp->hdr.seq);
_proto("Rx DATA %%%u { #%u }", serial, seq);
if (seq == 0)
goto protocol_error;
call->ackr_prev_seq = sp->hdr.seq;
/* received data implicitly ACKs all of the request packets we
* sent when we're acting as a client */
if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
rxrpc_assume_implicit_ackall(call, serial);
switch (rxrpc_fast_process_data(call, skb, seq)) {
case 0:
skb = NULL;
goto done;
default:
BUG();
/* data packet received beyond the last packet */
case -EBADMSG:
goto protocol_error;
}
case RXRPC_PACKET_TYPE_ACK:
/* ACK processing is done in process context */
read_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD) {
skb_queue_tail(&call->rx_queue, skb);
rxrpc_queue_call(call);
skb = NULL;
}
read_unlock_bh(&call->state_lock);
goto free_packet;
}
protocol_error:
_debug("protocol error");
write_lock_bh(&call->state_lock);
protocol_error_locked:
if (call->state <= RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->abort_code = RX_PROTOCOL_ERROR;
set_bit(RXRPC_CALL_ABORT, &call->events);
rxrpc_queue_call(call);
}
free_packet_unlock:
write_unlock_bh(&call->state_lock);
free_packet:
rxrpc_free_skb(skb);
done:
_leave("");
}
/*
* split up a jumbo data packet
*/
static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
struct sk_buff *jumbo)
{
struct rxrpc_jumbo_header jhdr;
struct rxrpc_skb_priv *sp;
struct sk_buff *part;
_enter(",{%u,%u}", jumbo->data_len, jumbo->len);
sp = rxrpc_skb(jumbo);
do {
sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
/* make a clone to represent the first subpacket in what's left
* of the jumbo packet */
part = skb_clone(jumbo, GFP_ATOMIC);
if (!part) {
/* simply ditch the tail in the event of ENOMEM */
pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
break;
}
rxrpc_new_skb(part);
pskb_trim(part, RXRPC_JUMBO_DATALEN);
if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
goto protocol_error;
if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
goto protocol_error;
if (!pskb_pull(jumbo, sizeof(jhdr)))
BUG();
sp->hdr.seq = htonl(ntohl(sp->hdr.seq) + 1);
sp->hdr.serial = htonl(ntohl(sp->hdr.serial) + 1);
sp->hdr.flags = jhdr.flags;
sp->hdr._rsvd = jhdr._rsvd;
_proto("Rx DATA Jumbo %%%u", ntohl(sp->hdr.serial) - 1);
rxrpc_fast_process_packet(call, part);
part = NULL;
} while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
rxrpc_fast_process_packet(call, jumbo);
_leave("");
return;
protocol_error:
_debug("protocol error");
rxrpc_free_skb(part);
rxrpc_free_skb(jumbo);
write_lock_bh(&call->state_lock);
if (call->state <= RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->abort_code = RX_PROTOCOL_ERROR;
set_bit(RXRPC_CALL_ABORT, &call->events);
rxrpc_queue_call(call);
}
write_unlock_bh(&call->state_lock);
_leave("");
}
/*
* post an incoming packet to the appropriate call/socket to deal with
* - must get rid of the sk_buff, either by freeing it or by queuing it
*/
static void rxrpc_post_packet_to_call(struct rxrpc_connection *conn,
struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_call *call;
struct rb_node *p;
__be32 call_id;
_enter("%p,%p", conn, skb);
read_lock_bh(&conn->lock);
sp = rxrpc_skb(skb);
/* look at extant calls by channel number first */
call = conn->channels[ntohl(sp->hdr.cid) & RXRPC_CHANNELMASK];
if (!call || call->call_id != sp->hdr.callNumber)
goto call_not_extant;
_debug("extant call [%d]", call->state);
ASSERTCMP(call->conn, ==, conn);
read_lock(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_LOCALLY_ABORTED:
if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
rxrpc_queue_call(call);
case RXRPC_CALL_REMOTELY_ABORTED:
case RXRPC_CALL_NETWORK_ERROR:
case RXRPC_CALL_DEAD:
goto free_unlock;
default:
break;
}
read_unlock(&call->state_lock);
rxrpc_get_call(call);
read_unlock_bh(&conn->lock);
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
sp->hdr.flags & RXRPC_JUMBO_PACKET)
rxrpc_process_jumbo_packet(call, skb);
else
rxrpc_fast_process_packet(call, skb);
rxrpc_put_call(call);
goto done;
call_not_extant:
/* search the completed calls in case what we're dealing with is
* there */
_debug("call not extant");
call_id = sp->hdr.callNumber;
p = conn->calls.rb_node;
while (p) {
call = rb_entry(p, struct rxrpc_call, conn_node);
if (call_id < call->call_id)
p = p->rb_left;
else if (call_id > call->call_id)
p = p->rb_right;
else
goto found_completed_call;
}
dead_call:
/* it's a either a really old call that we no longer remember or its a
* new incoming call */
read_unlock_bh(&conn->lock);
if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
sp->hdr.seq == __constant_cpu_to_be32(1)) {
_debug("incoming call");
skb_queue_tail(&conn->trans->local->accept_queue, skb);
rxrpc_queue_work(&conn->trans->local->acceptor);
goto done;
}
_debug("dead call");
skb->priority = RX_CALL_DEAD;
rxrpc_reject_packet(conn->trans->local, skb);
goto done;
/* resend last packet of a completed call
* - client calls may have been aborted or ACK'd
* - server calls may have been aborted
*/
found_completed_call:
_debug("completed call");
if (atomic_read(&call->usage) == 0)
goto dead_call;
/* synchronise any state changes */
read_lock(&call->state_lock);
ASSERTIFCMP(call->state != RXRPC_CALL_CLIENT_FINAL_ACK,
call->state, >=, RXRPC_CALL_COMPLETE);
if (call->state == RXRPC_CALL_LOCALLY_ABORTED ||
call->state == RXRPC_CALL_REMOTELY_ABORTED ||
call->state == RXRPC_CALL_DEAD) {
read_unlock(&call->state_lock);
goto dead_call;
}
if (call->conn->in_clientflag) {
read_unlock(&call->state_lock);
goto dead_call; /* complete server call */
}
_debug("final ack again");
rxrpc_get_call(call);
set_bit(RXRPC_CALL_ACK_FINAL, &call->events);
rxrpc_queue_call(call);
free_unlock:
read_unlock(&call->state_lock);
read_unlock_bh(&conn->lock);
rxrpc_free_skb(skb);
done:
_leave("");
}
/*
* post connection-level events to the connection
* - this includes challenges, responses and some aborts
*/
static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
struct sk_buff *skb)
{
_enter("%p,%p", conn, skb);
atomic_inc(&conn->usage);
skb_queue_tail(&conn->rx_queue, skb);
rxrpc_queue_conn(conn);
}
/*
* handle data received on the local endpoint
* - may be called in interrupt context
*/
void rxrpc_data_ready(struct sock *sk, int count)
{
struct rxrpc_connection *conn;
struct rxrpc_transport *trans;
struct rxrpc_skb_priv *sp;
struct rxrpc_local *local;
struct rxrpc_peer *peer;
struct sk_buff *skb;
int ret;
_enter("%p, %d", sk, count);
ASSERT(!irqs_disabled());
read_lock_bh(&rxrpc_local_lock);
local = sk->sk_user_data;
if (local && atomic_read(&local->usage) > 0)
rxrpc_get_local(local);
else
local = NULL;
read_unlock_bh(&rxrpc_local_lock);
if (!local) {
_leave(" [local dead]");
return;
}
skb = skb_recv_datagram(sk, 0, 1, &ret);
if (!skb) {
rxrpc_put_local(local);
if (ret == -EAGAIN)
return;
_debug("UDP socket error %d", ret);
return;
}
rxrpc_new_skb(skb);
_net("recv skb %p", skb);
/* we'll probably need to checksum it (didn't call sock_recvmsg) */
if (skb_checksum_complete(skb)) {
rxrpc_free_skb(skb);
rxrpc_put_local(local);
_leave(" [CSUM failed]");
return;
}
/* the socket buffer we have is owned by UDP, with UDP's data all over
* it, but we really want our own */
skb_orphan(skb);
sp = rxrpc_skb(skb);
memset(sp, 0, sizeof(*sp));
_net("Rx UDP packet from %08x:%04hu",
ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
/* dig out the RxRPC connection details */
if (skb_copy_bits(skb, sizeof(struct udphdr), &sp->hdr,
sizeof(sp->hdr)) < 0)
goto bad_message;
if (!pskb_pull(skb, sizeof(struct udphdr) + sizeof(sp->hdr)))
BUG();
_net("Rx RxRPC %s ep=%x call=%x:%x",
sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
ntohl(sp->hdr.epoch),
ntohl(sp->hdr.cid),
ntohl(sp->hdr.callNumber));
if (sp->hdr.type == 0 || sp->hdr.type >= RXRPC_N_PACKET_TYPES) {
_proto("Rx Bad Packet Type %u", sp->hdr.type);
goto bad_message;
}
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
(sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
goto bad_message;
peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr, udp_hdr(skb)->source);
if (IS_ERR(peer))
goto cant_route_call;
trans = rxrpc_find_transport(local, peer);
rxrpc_put_peer(peer);
if (!trans)
goto cant_route_call;
conn = rxrpc_find_connection(trans, &sp->hdr);
rxrpc_put_transport(trans);
if (!conn)
goto cant_route_call;
_debug("CONN %p {%d}", conn, conn->debug_id);
if (sp->hdr.callNumber == 0)
rxrpc_post_packet_to_conn(conn, skb);
else
rxrpc_post_packet_to_call(conn, skb);
rxrpc_put_connection(conn);
rxrpc_put_local(local);
return;
cant_route_call:
_debug("can't route call");
if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
if (sp->hdr.seq == __constant_cpu_to_be32(1)) {
_debug("first packet");
skb_queue_tail(&local->accept_queue, skb);
rxrpc_queue_work(&local->acceptor);
rxrpc_put_local(local);
_leave(" [incoming]");
return;
}
skb->priority = RX_INVALID_OPERATION;
} else {
skb->priority = RX_CALL_DEAD;
}
_debug("reject");
rxrpc_reject_packet(local, skb);
rxrpc_put_local(local);
_leave(" [no call]");
return;
bad_message:
skb->priority = RX_PROTOCOL_ERROR;
rxrpc_reject_packet(local, skb);
rxrpc_put_local(local);
_leave(" [badmsg]");
}
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