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linux-hardened/fs/afs/rxrpc.c
David Howells 0e119b41b7 rxrpc: Limit the listening backlog 
Limit the socket incoming call backlog queue size so that a remote client
can't pump in sufficient new calls that the server runs out of memory.  Note
that this is partially theoretical at the moment since whilst the number of
calls is limited, the number of packets trying to set up new calls is not.
This will be addressed in a later patch.

If the caller of listen() specifies a backlog INT_MAX, then they get the
current maximum; anything else greater than max_backlog or anything
negative incurs EINVAL.

The limit on the maximum queue size can be set by:

	echo N >/proc/sys/net/rxrpc/max_backlog

where 4<=N<=32.

Further, set the default backlog to 0, requiring listen() to be called
before we start actually queueing new calls.  Whilst this kind of is a
change in the UAPI, the caller can't actually *accept* new calls anyway
unless they've first called listen() to put the socket into the LISTENING
state - thus the aforementioned new calls would otherwise just sit there,
eating up kernel memory.  (Note that sockets that don't have a non-zero
service ID bound don't get incoming calls anyway.)

Given that the default backlog is now 0, make the AFS filesystem call
kernel_listen() to set the maximum backlog for itself.

Possible improvements include:

 (1) Trimming a too-large backlog to max_backlog when listen is called.

 (2) Trimming the backlog value whenever the value is used so that changes
     to max_backlog are applied to an open socket automatically.  Note that
     the AFS filesystem opens one socket and keeps it open for extended
     periods, so would miss out on changes to max_backlog.

 (3) Having a separate setting for the AFS filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 18:14:47 -07:00

884 lines
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/* Maintain an RxRPC server socket to do AFS communications through
*
* 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/slab.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <rxrpc/packet.h>
#include "internal.h"
#include "afs_cm.h"
static struct socket *afs_socket; /* my RxRPC socket */
static struct workqueue_struct *afs_async_calls;
static atomic_t afs_outstanding_calls;
static atomic_t afs_outstanding_skbs;
static void afs_wake_up_call_waiter(struct afs_call *);
static int afs_wait_for_call_to_complete(struct afs_call *);
static void afs_wake_up_async_call(struct afs_call *);
static int afs_dont_wait_for_call_to_complete(struct afs_call *);
static void afs_process_async_call(struct afs_call *);
static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *);
static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool);
/* synchronous call management */
const struct afs_wait_mode afs_sync_call = {
.rx_wakeup = afs_wake_up_call_waiter,
.wait = afs_wait_for_call_to_complete,
};
/* asynchronous call management */
const struct afs_wait_mode afs_async_call = {
.rx_wakeup = afs_wake_up_async_call,
.wait = afs_dont_wait_for_call_to_complete,
};
/* asynchronous incoming call management */
static const struct afs_wait_mode afs_async_incoming_call = {
.rx_wakeup = afs_wake_up_async_call,
};
/* asynchronous incoming call initial processing */
static const struct afs_call_type afs_RXCMxxxx = {
.name = "CB.xxxx",
.deliver = afs_deliver_cm_op_id,
.abort_to_error = afs_abort_to_error,
};
static void afs_collect_incoming_call(struct work_struct *);
static struct sk_buff_head afs_incoming_calls;
static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
static void afs_async_workfn(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
call->async_workfn(call);
}
static int afs_wait_atomic_t(atomic_t *p)
{
schedule();
return 0;
}
/*
* open an RxRPC socket and bind it to be a server for callback notifications
* - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
*/
int afs_open_socket(void)
{
struct sockaddr_rxrpc srx;
struct socket *socket;
int ret;
_enter("");
skb_queue_head_init(&afs_incoming_calls);
ret = -ENOMEM;
afs_async_calls = create_singlethread_workqueue("kafsd");
if (!afs_async_calls)
goto error_0;
ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
if (ret < 0)
goto error_1;
socket->sk->sk_allocation = GFP_NOFS;
/* bind the callback manager's address to make this a server socket */
srx.srx_family = AF_RXRPC;
srx.srx_service = CM_SERVICE;
srx.transport_type = SOCK_DGRAM;
srx.transport_len = sizeof(srx.transport.sin);
srx.transport.sin.sin_family = AF_INET;
srx.transport.sin.sin_port = htons(AFS_CM_PORT);
memset(&srx.transport.sin.sin_addr, 0,
sizeof(srx.transport.sin.sin_addr));
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
if (ret < 0)
goto error_2;
ret = kernel_listen(socket, INT_MAX);
if (ret < 0)
goto error_2;
rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
afs_socket = socket;
_leave(" = 0");
return 0;
error_2:
sock_release(socket);
error_1:
destroy_workqueue(afs_async_calls);
error_0:
_leave(" = %d", ret);
return ret;
}
/*
* close the RxRPC socket AFS was using
*/
void afs_close_socket(void)
{
_enter("");
wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
TASK_UNINTERRUPTIBLE);
_debug("no outstanding calls");
sock_release(afs_socket);
_debug("dework");
destroy_workqueue(afs_async_calls);
ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
_leave("");
}
/*
* note that the data in a socket buffer is now delivered and that the buffer
* should be freed
*/
static void afs_data_delivered(struct sk_buff *skb)
{
if (!skb) {
_debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
dump_stack();
} else {
_debug("DLVR %p{%u} [%d]",
skb, skb->mark, atomic_read(&afs_outstanding_skbs));
if (atomic_dec_return(&afs_outstanding_skbs) == -1)
BUG();
rxrpc_kernel_data_delivered(skb);
}
}
/*
* free a socket buffer
*/
static void afs_free_skb(struct sk_buff *skb)
{
if (!skb) {
_debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
dump_stack();
} else {
_debug("FREE %p{%u} [%d]",
skb, skb->mark, atomic_read(&afs_outstanding_skbs));
if (atomic_dec_return(&afs_outstanding_skbs) == -1)
BUG();
rxrpc_kernel_free_skb(skb);
}
}
/*
* free a call
*/
static void afs_free_call(struct afs_call *call)
{
_debug("DONE %p{%s} [%d]",
call, call->type->name, atomic_read(&afs_outstanding_calls));
ASSERTCMP(call->rxcall, ==, NULL);
ASSERT(!work_pending(&call->async_work));
ASSERT(skb_queue_empty(&call->rx_queue));
ASSERT(call->type->name != NULL);
kfree(call->request);
kfree(call);
if (atomic_dec_and_test(&afs_outstanding_calls))
wake_up_atomic_t(&afs_outstanding_calls);
}
/*
* End a call but do not free it
*/
static void afs_end_call_nofree(struct afs_call *call)
{
if (call->rxcall) {
rxrpc_kernel_end_call(call->rxcall);
call->rxcall = NULL;
}
if (call->type->destructor)
call->type->destructor(call);
}
/*
* End a call and free it
*/
static void afs_end_call(struct afs_call *call)
{
afs_end_call_nofree(call);
afs_free_call(call);
}
/*
* allocate a call with flat request and reply buffers
*/
struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
size_t request_size, size_t reply_size)
{
struct afs_call *call;
call = kzalloc(sizeof(*call), GFP_NOFS);
if (!call)
goto nomem_call;
_debug("CALL %p{%s} [%d]",
call, type->name, atomic_read(&afs_outstanding_calls));
atomic_inc(&afs_outstanding_calls);
call->type = type;
call->request_size = request_size;
call->reply_max = reply_size;
if (request_size) {
call->request = kmalloc(request_size, GFP_NOFS);
if (!call->request)
goto nomem_free;
}
if (reply_size) {
call->buffer = kmalloc(reply_size, GFP_NOFS);
if (!call->buffer)
goto nomem_free;
}
init_waitqueue_head(&call->waitq);
skb_queue_head_init(&call->rx_queue);
return call;
nomem_free:
afs_free_call(call);
nomem_call:
return NULL;
}
/*
* clean up a call with flat buffer
*/
void afs_flat_call_destructor(struct afs_call *call)
{
_enter("");
kfree(call->request);
call->request = NULL;
kfree(call->buffer);
call->buffer = NULL;
}
/*
* attach the data from a bunch of pages on an inode to a call
*/
static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
struct kvec *iov)
{
struct page *pages[8];
unsigned count, n, loop, offset, to;
pgoff_t first = call->first, last = call->last;
int ret;
_enter("");
offset = call->first_offset;
call->first_offset = 0;
do {
_debug("attach %lx-%lx", first, last);
count = last - first + 1;
if (count > ARRAY_SIZE(pages))
count = ARRAY_SIZE(pages);
n = find_get_pages_contig(call->mapping, first, count, pages);
ASSERTCMP(n, ==, count);
loop = 0;
do {
msg->msg_flags = 0;
to = PAGE_SIZE;
if (first + loop >= last)
to = call->last_to;
else
msg->msg_flags = MSG_MORE;
iov->iov_base = kmap(pages[loop]) + offset;
iov->iov_len = to - offset;
offset = 0;
_debug("- range %u-%u%s",
offset, to, msg->msg_flags ? " [more]" : "");
iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
iov, 1, to - offset);
/* have to change the state *before* sending the last
* packet as RxRPC might give us the reply before it
* returns from sending the request */
if (first + loop >= last)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(call->rxcall, msg,
to - offset);
kunmap(pages[loop]);
if (ret < 0)
break;
} while (++loop < count);
first += count;
for (loop = 0; loop < count; loop++)
put_page(pages[loop]);
if (ret < 0)
break;
} while (first <= last);
_leave(" = %d", ret);
return ret;
}
/*
* initiate a call
*/
int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
const struct afs_wait_mode *wait_mode)
{
struct sockaddr_rxrpc srx;
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
int ret;
struct sk_buff *skb;
_enter("%x,{%d},", addr->s_addr, ntohs(call->port));
ASSERT(call->type != NULL);
ASSERT(call->type->name != NULL);
_debug("____MAKE %p{%s,%x} [%d]____",
call, call->type->name, key_serial(call->key),
atomic_read(&afs_outstanding_calls));
call->wait_mode = wait_mode;
call->async_workfn = afs_process_async_call;
INIT_WORK(&call->async_work, afs_async_workfn);
memset(&srx, 0, sizeof(srx));
srx.srx_family = AF_RXRPC;
srx.srx_service = call->service_id;
srx.transport_type = SOCK_DGRAM;
srx.transport_len = sizeof(srx.transport.sin);
srx.transport.sin.sin_family = AF_INET;
srx.transport.sin.sin_port = call->port;
memcpy(&srx.transport.sin.sin_addr, addr, 4);
/* create a call */
rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
(unsigned long) call, gfp);
call->key = NULL;
if (IS_ERR(rxcall)) {
ret = PTR_ERR(rxcall);
goto error_kill_call;
}
call->rxcall = rxcall;
/* send the request */
iov[0].iov_base = call->request;
iov[0].iov_len = call->request_size;
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
call->request_size);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
/* have to change the state *before* sending the last packet as RxRPC
* might give us the reply before it returns from sending the
* request */
if (!call->send_pages)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
if (ret < 0)
goto error_do_abort;
if (call->send_pages) {
ret = afs_send_pages(call, &msg, iov);
if (ret < 0)
goto error_do_abort;
}
/* at this point, an async call may no longer exist as it may have
* already completed */
return wait_mode->wait(call);
error_do_abort:
rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
while ((skb = skb_dequeue(&call->rx_queue)))
afs_free_skb(skb);
error_kill_call:
afs_end_call(call);
_leave(" = %d", ret);
return ret;
}
/*
* Handles intercepted messages that were arriving in the socket's Rx queue.
*
* Called from the AF_RXRPC call processor in waitqueue process context. For
* each call, it is guaranteed this will be called in order of packet to be
* delivered.
*/
static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
struct sk_buff *skb)
{
struct afs_call *call = (struct afs_call *) user_call_ID;
_enter("%p,,%u", call, skb->mark);
_debug("ICPT %p{%u} [%d]",
skb, skb->mark, atomic_read(&afs_outstanding_skbs));
ASSERTCMP(sk, ==, afs_socket->sk);
atomic_inc(&afs_outstanding_skbs);
if (!call) {
/* its an incoming call for our callback service */
skb_queue_tail(&afs_incoming_calls, skb);
queue_work(afs_wq, &afs_collect_incoming_call_work);
} else {
/* route the messages directly to the appropriate call */
skb_queue_tail(&call->rx_queue, skb);
call->wait_mode->rx_wakeup(call);
}
_leave("");
}
/*
* deliver messages to a call
*/
static void afs_deliver_to_call(struct afs_call *call)
{
struct sk_buff *skb;
bool last;
u32 abort_code;
int ret;
_enter("");
while ((call->state == AFS_CALL_AWAIT_REPLY ||
call->state == AFS_CALL_AWAIT_OP_ID ||
call->state == AFS_CALL_AWAIT_REQUEST ||
call->state == AFS_CALL_AWAIT_ACK) &&
(skb = skb_dequeue(&call->rx_queue))) {
switch (skb->mark) {
case RXRPC_SKB_MARK_DATA:
_debug("Rcv DATA");
last = rxrpc_kernel_is_data_last(skb);
ret = call->type->deliver(call, skb, last);
switch (ret) {
case 0:
if (last &&
call->state == AFS_CALL_AWAIT_REPLY)
call->state = AFS_CALL_COMPLETE;
break;
case -ENOTCONN:
abort_code = RX_CALL_DEAD;
goto do_abort;
case -ENOTSUPP:
abort_code = RX_INVALID_OPERATION;
goto do_abort;
default:
abort_code = RXGEN_CC_UNMARSHAL;
if (call->state != AFS_CALL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
do_abort:
rxrpc_kernel_abort_call(call->rxcall,
abort_code);
call->error = ret;
call->state = AFS_CALL_ERROR;
break;
}
afs_data_delivered(skb);
skb = NULL;
continue;
case RXRPC_SKB_MARK_FINAL_ACK:
_debug("Rcv ACK");
call->state = AFS_CALL_COMPLETE;
break;
case RXRPC_SKB_MARK_BUSY:
_debug("Rcv BUSY");
call->error = -EBUSY;
call->state = AFS_CALL_BUSY;
break;
case RXRPC_SKB_MARK_REMOTE_ABORT:
abort_code = rxrpc_kernel_get_abort_code(skb);
call->error = call->type->abort_to_error(abort_code);
call->state = AFS_CALL_ABORTED;
_debug("Rcv ABORT %u -> %d", abort_code, call->error);
break;
case RXRPC_SKB_MARK_LOCAL_ABORT:
abort_code = rxrpc_kernel_get_abort_code(skb);
call->error = call->type->abort_to_error(abort_code);
call->state = AFS_CALL_ABORTED;
_debug("Loc ABORT %u -> %d", abort_code, call->error);
break;
case RXRPC_SKB_MARK_NET_ERROR:
call->error = -rxrpc_kernel_get_error_number(skb);
call->state = AFS_CALL_ERROR;
_debug("Rcv NET ERROR %d", call->error);
break;
case RXRPC_SKB_MARK_LOCAL_ERROR:
call->error = -rxrpc_kernel_get_error_number(skb);
call->state = AFS_CALL_ERROR;
_debug("Rcv LOCAL ERROR %d", call->error);
break;
default:
BUG();
break;
}
afs_free_skb(skb);
}
/* make sure the queue is empty if the call is done with (we might have
* aborted the call early because of an unmarshalling error) */
if (call->state >= AFS_CALL_COMPLETE) {
while ((skb = skb_dequeue(&call->rx_queue)))
afs_free_skb(skb);
if (call->incoming)
afs_end_call(call);
}
_leave("");
}
/*
* wait synchronously for a call to complete
*/
static int afs_wait_for_call_to_complete(struct afs_call *call)
{
struct sk_buff *skb;
int ret;
DECLARE_WAITQUEUE(myself, current);
_enter("");
add_wait_queue(&call->waitq, &myself);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
/* deliver any messages that are in the queue */
if (!skb_queue_empty(&call->rx_queue)) {
__set_current_state(TASK_RUNNING);
afs_deliver_to_call(call);
continue;
}
ret = call->error;
if (call->state >= AFS_CALL_COMPLETE)
break;
ret = -EINTR;
if (signal_pending(current))
break;
schedule();
}
remove_wait_queue(&call->waitq, &myself);
__set_current_state(TASK_RUNNING);
/* kill the call */
if (call->state < AFS_CALL_COMPLETE) {
_debug("call incomplete");
rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
while ((skb = skb_dequeue(&call->rx_queue)))
afs_free_skb(skb);
}
_debug("call complete");
afs_end_call(call);
_leave(" = %d", ret);
return ret;
}
/*
* wake up a waiting call
*/
static void afs_wake_up_call_waiter(struct afs_call *call)
{
wake_up(&call->waitq);
}
/*
* wake up an asynchronous call
*/
static void afs_wake_up_async_call(struct afs_call *call)
{
_enter("");
queue_work(afs_async_calls, &call->async_work);
}
/*
* put a call into asynchronous mode
* - mustn't touch the call descriptor as the call my have completed by the
* time we get here
*/
static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
{
_enter("");
return -EINPROGRESS;
}
/*
* delete an asynchronous call
*/
static void afs_delete_async_call(struct afs_call *call)
{
_enter("");
afs_free_call(call);
_leave("");
}
/*
* perform processing on an asynchronous call
* - on a multiple-thread workqueue this work item may try to run on several
* CPUs at the same time
*/
static void afs_process_async_call(struct afs_call *call)
{
_enter("");
if (!skb_queue_empty(&call->rx_queue))
afs_deliver_to_call(call);
if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
if (call->wait_mode->async_complete)
call->wait_mode->async_complete(call->reply,
call->error);
call->reply = NULL;
/* kill the call */
afs_end_call_nofree(call);
/* we can't just delete the call because the work item may be
* queued */
call->async_workfn = afs_delete_async_call;
queue_work(afs_async_calls, &call->async_work);
}
_leave("");
}
/*
* empty a socket buffer into a flat reply buffer
*/
void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
{
size_t len = skb->len;
if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0)
BUG();
call->reply_size += len;
}
/*
* accept the backlog of incoming calls
*/
static void afs_collect_incoming_call(struct work_struct *work)
{
struct rxrpc_call *rxcall;
struct afs_call *call = NULL;
struct sk_buff *skb;
while ((skb = skb_dequeue(&afs_incoming_calls))) {
_debug("new call");
/* don't need the notification */
afs_free_skb(skb);
if (!call) {
call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
if (!call) {
rxrpc_kernel_reject_call(afs_socket);
return;
}
call->async_workfn = afs_process_async_call;
INIT_WORK(&call->async_work, afs_async_workfn);
call->wait_mode = &afs_async_incoming_call;
call->type = &afs_RXCMxxxx;
init_waitqueue_head(&call->waitq);
skb_queue_head_init(&call->rx_queue);
call->state = AFS_CALL_AWAIT_OP_ID;
_debug("CALL %p{%s} [%d]",
call, call->type->name,
atomic_read(&afs_outstanding_calls));
atomic_inc(&afs_outstanding_calls);
}
rxcall = rxrpc_kernel_accept_call(afs_socket,
(unsigned long) call);
if (!IS_ERR(rxcall)) {
call->rxcall = rxcall;
call = NULL;
}
}
if (call)
afs_free_call(call);
}
/*
* grab the operation ID from an incoming cache manager call
*/
static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
bool last)
{
size_t len = skb->len;
void *oibuf = (void *) &call->operation_ID;
_enter("{%u},{%zu},%d", call->offset, len, last);
ASSERTCMP(call->offset, <, 4);
/* the operation ID forms the first four bytes of the request data */
len = min_t(size_t, len, 4 - call->offset);
if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
BUG();
if (!pskb_pull(skb, len))
BUG();
call->offset += len;
if (call->offset < 4) {
if (last) {
_leave(" = -EBADMSG [op ID short]");
return -EBADMSG;
}
_leave(" = 0 [incomplete]");
return 0;
}
call->state = AFS_CALL_AWAIT_REQUEST;
/* ask the cache manager to route the call (it'll change the call type
* if successful) */
if (!afs_cm_incoming_call(call))
return -ENOTSUPP;
/* pass responsibility for the remainer of this message off to the
* cache manager op */
return call->type->deliver(call, skb, last);
}
/*
* send an empty reply
*/
void afs_send_empty_reply(struct afs_call *call)
{
struct msghdr msg;
_enter("");
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
call->state = AFS_CALL_AWAIT_ACK;
switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
case 0:
_leave(" [replied]");
return;
case -ENOMEM:
_debug("oom");
rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
default:
afs_end_call(call);
_leave(" [error]");
return;
}
}
/*
* send a simple reply
*/
void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
{
struct msghdr msg;
struct kvec iov[1];
int n;
_enter("");
iov[0].iov_base = (void *) buf;
iov[0].iov_len = len;
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
call->state = AFS_CALL_AWAIT_ACK;
n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
if (n >= 0) {
/* Success */
_leave(" [replied]");
return;
}
if (n == -ENOMEM) {
_debug("oom");
rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
}
afs_end_call(call);
_leave(" [error]");
}
/*
* extract a piece of data from the received data socket buffers
*/
int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
bool last, void *buf, size_t count)
{
size_t len = skb->len;
_enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
ASSERTCMP(call->offset, <, count);
len = min_t(size_t, len, count - call->offset);
if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
!pskb_pull(skb, len))
BUG();
call->offset += len;
if (call->offset < count) {
if (last) {
_leave(" = -EBADMSG [%d < %zu]", call->offset, count);
return -EBADMSG;
}
_leave(" = -EAGAIN");
return -EAGAIN;
}
return 0;
}
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