linux_dsm_epyc7002/fs/afs/rxrpc.c
David Howells e754eba685 rxrpc: Provide a cmsg to specify the amount of Tx data for a call
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-07 17:15:46 +01:00

857 lines
20 KiB
C

/* 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 <linux/sched/signal.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <rxrpc/packet.h>
#include "internal.h"
#include "afs_cm.h"
struct socket *afs_socket; /* my RxRPC socket */
static struct workqueue_struct *afs_async_calls;
static struct afs_call *afs_spare_incoming_call;
atomic_t afs_outstanding_calls;
static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
static int afs_wait_for_call_to_complete(struct afs_call *);
static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_process_async_call(struct work_struct *);
static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
static int afs_deliver_cm_op_id(struct afs_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_charge_preallocation(struct work_struct *);
static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
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("");
ret = -ENOMEM;
afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
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;
rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
afs_rx_discard_new_call);
ret = kernel_listen(socket, INT_MAX);
if (ret < 0)
goto error_2;
afs_socket = socket;
afs_charge_preallocation(NULL);
_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("");
kernel_listen(afs_socket, 0);
flush_workqueue(afs_async_calls);
if (afs_spare_incoming_call) {
afs_put_call(afs_spare_incoming_call);
afs_spare_incoming_call = NULL;
}
_debug("outstanding %u", atomic_read(&afs_outstanding_calls));
wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
TASK_UNINTERRUPTIBLE);
_debug("no outstanding calls");
kernel_sock_shutdown(afs_socket, SHUT_RDWR);
flush_workqueue(afs_async_calls);
sock_release(afs_socket);
_debug("dework");
destroy_workqueue(afs_async_calls);
_leave("");
}
/*
* Allocate a call.
*/
static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
gfp_t gfp)
{
struct afs_call *call;
int o;
call = kzalloc(sizeof(*call), gfp);
if (!call)
return NULL;
call->type = type;
atomic_set(&call->usage, 1);
INIT_WORK(&call->async_work, afs_process_async_call);
init_waitqueue_head(&call->waitq);
o = atomic_inc_return(&afs_outstanding_calls);
trace_afs_call(call, afs_call_trace_alloc, 1, o,
__builtin_return_address(0));
return call;
}
/*
* Dispose of a reference on a call.
*/
void afs_put_call(struct afs_call *call)
{
int n = atomic_dec_return(&call->usage);
int o = atomic_read(&afs_outstanding_calls);
trace_afs_call(call, afs_call_trace_put, n + 1, o,
__builtin_return_address(0));
ASSERTCMP(n, >=, 0);
if (n == 0) {
ASSERT(!work_pending(&call->async_work));
ASSERT(call->type->name != NULL);
if (call->rxcall) {
rxrpc_kernel_end_call(afs_socket, call->rxcall);
call->rxcall = NULL;
}
if (call->type->destructor)
call->type->destructor(call);
kfree(call->request);
kfree(call);
o = atomic_dec_return(&afs_outstanding_calls);
trace_afs_call(call, afs_call_trace_free, 0, o,
__builtin_return_address(0));
if (o == 0)
wake_up_atomic_t(&afs_outstanding_calls);
}
}
/*
* Queue the call for actual work. Returns 0 unconditionally for convenience.
*/
int afs_queue_call_work(struct afs_call *call)
{
int u = atomic_inc_return(&call->usage);
trace_afs_call(call, afs_call_trace_work, u,
atomic_read(&afs_outstanding_calls),
__builtin_return_address(0));
INIT_WORK(&call->work, call->type->work);
if (!queue_work(afs_wq, &call->work))
afs_put_call(call);
return 0;
}
/*
* 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_max)
{
struct afs_call *call;
call = afs_alloc_call(type, GFP_NOFS);
if (!call)
goto nomem_call;
if (request_size) {
call->request_size = request_size;
call->request = kmalloc(request_size, GFP_NOFS);
if (!call->request)
goto nomem_free;
}
if (reply_max) {
call->reply_max = reply_max;
call->buffer = kmalloc(reply_max, GFP_NOFS);
if (!call->buffer)
goto nomem_free;
}
init_waitqueue_head(&call->waitq);
return call;
nomem_free:
afs_put_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;
}
#define AFS_BVEC_MAX 8
/*
* Load the given bvec with the next few pages.
*/
static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
struct bio_vec *bv, pgoff_t first, pgoff_t last,
unsigned offset)
{
struct page *pages[AFS_BVEC_MAX];
unsigned int nr, n, i, to, bytes = 0;
nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
n = find_get_pages_contig(call->mapping, first, nr, pages);
ASSERTCMP(n, ==, nr);
msg->msg_flags |= MSG_MORE;
for (i = 0; i < nr; i++) {
to = PAGE_SIZE;
if (first + i >= last) {
to = call->last_to;
msg->msg_flags &= ~MSG_MORE;
}
bv[i].bv_page = pages[i];
bv[i].bv_len = to - offset;
bv[i].bv_offset = offset;
bytes += to - offset;
offset = 0;
}
iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
}
/*
* 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 bio_vec bv[AFS_BVEC_MAX];
unsigned int bytes, nr, loop, offset;
pgoff_t first = call->first, last = call->last;
int ret;
offset = call->first_offset;
call->first_offset = 0;
do {
afs_load_bvec(call, msg, bv, first, last, offset);
offset = 0;
bytes = msg->msg_iter.count;
nr = msg->msg_iter.nr_segs;
/* 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 + nr - 1 >= last)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
msg, bytes);
for (loop = 0; loop < nr; loop++)
put_page(bv[loop].bv_page);
if (ret < 0)
break;
first += nr;
} while (first <= last);
return ret;
}
/*
* initiate a call
*/
int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
bool async)
{
struct sockaddr_rxrpc srx;
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
size_t offset;
s64 tx_total_len;
u32 abort_code;
int ret;
_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->async = async;
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);
/* Work out the length we're going to transmit. This is awkward for
* calls such as FS.StoreData where there's an extra injection of data
* after the initial fixed part.
*/
tx_total_len = call->request_size;
if (call->send_pages) {
tx_total_len += call->last_to - call->first_offset;
tx_total_len += (call->last - call->first) * PAGE_SIZE;
}
/* create a call */
rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
(unsigned long)call,
tx_total_len, gfp,
(async ?
afs_wake_up_async_call :
afs_wake_up_call_waiter));
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);
/* We have to change the state *before* sending the last packet as
* rxrpc might give us the reply before it returns from sending the
* request. Further, if the send fails, we may already have been given
* a notification and may have collected it.
*/
if (!call->send_pages)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(afs_socket, rxcall,
&msg, call->request_size);
if (ret < 0)
goto error_do_abort;
if (call->send_pages) {
ret = afs_send_pages(call, &msg);
if (ret < 0)
goto error_do_abort;
}
/* at this point, an async call may no longer exist as it may have
* already completed */
if (call->async)
return -EINPROGRESS;
return afs_wait_for_call_to_complete(call);
error_do_abort:
call->state = AFS_CALL_COMPLETE;
if (ret != -ECONNABORTED) {
rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT,
ret, "KSD");
} else {
abort_code = 0;
offset = 0;
rxrpc_kernel_recv_data(afs_socket, rxcall, NULL, 0, &offset,
false, &abort_code);
ret = call->type->abort_to_error(abort_code);
}
error_kill_call:
afs_put_call(call);
_leave(" = %d", ret);
return ret;
}
/*
* deliver messages to a call
*/
static void afs_deliver_to_call(struct afs_call *call)
{
u32 abort_code;
int ret;
_enter("%s", call->type->name);
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
) {
if (call->state == AFS_CALL_AWAIT_ACK) {
size_t offset = 0;
ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
NULL, 0, &offset, false,
&call->abort_code);
trace_afs_recv_data(call, 0, offset, false, ret);
if (ret == -EINPROGRESS || ret == -EAGAIN)
return;
if (ret == 1 || ret < 0) {
call->state = AFS_CALL_COMPLETE;
goto done;
}
return;
}
ret = call->type->deliver(call);
switch (ret) {
case 0:
if (call->state == AFS_CALL_AWAIT_REPLY)
call->state = AFS_CALL_COMPLETE;
goto done;
case -EINPROGRESS:
case -EAGAIN:
goto out;
case -ECONNABORTED:
goto call_complete;
case -ENOTCONN:
abort_code = RX_CALL_DEAD;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code, ret, "KNC");
goto save_error;
case -ENOTSUPP:
abort_code = RXGEN_OPCODE;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code, ret, "KIV");
goto save_error;
case -ENODATA:
case -EBADMSG:
case -EMSGSIZE:
default:
abort_code = RXGEN_CC_UNMARSHAL;
if (call->state != AFS_CALL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code, -EBADMSG, "KUM");
goto save_error;
}
}
done:
if (call->state == AFS_CALL_COMPLETE && call->incoming)
afs_put_call(call);
out:
_leave("");
return;
save_error:
call->error = ret;
call_complete:
call->state = AFS_CALL_COMPLETE;
goto done;
}
/*
* wait synchronously for a call to complete
*/
static int afs_wait_for_call_to_complete(struct afs_call *call)
{
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 (call->state < AFS_CALL_COMPLETE && call->need_attention) {
call->need_attention = false;
__set_current_state(TASK_RUNNING);
afs_deliver_to_call(call);
continue;
}
if (call->state == AFS_CALL_COMPLETE ||
signal_pending(current))
break;
schedule();
}
remove_wait_queue(&call->waitq, &myself);
__set_current_state(TASK_RUNNING);
/* Kill off the call if it's still live. */
if (call->state < AFS_CALL_COMPLETE) {
_debug("call interrupted");
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_USER_ABORT, -EINTR, "KWI");
}
ret = call->error;
_debug("call complete");
afs_put_call(call);
_leave(" = %d", ret);
return ret;
}
/*
* wake up a waiting call
*/
static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
call->need_attention = true;
wake_up(&call->waitq);
}
/*
* wake up an asynchronous call
*/
static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
int u;
trace_afs_notify_call(rxcall, call);
call->need_attention = true;
u = __atomic_add_unless(&call->usage, 1, 0);
if (u != 0) {
trace_afs_call(call, afs_call_trace_wake, u,
atomic_read(&afs_outstanding_calls),
__builtin_return_address(0));
if (!queue_work(afs_async_calls, &call->async_work))
afs_put_call(call);
}
}
/*
* Delete an asynchronous call. The work item carries a ref to the call struct
* that we need to release.
*/
static void afs_delete_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
afs_put_call(call);
_leave("");
}
/*
* Perform I/O processing on an asynchronous call. The work item carries a ref
* to the call struct that we either need to release or to pass on.
*/
static void afs_process_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
call->need_attention = false;
afs_deliver_to_call(call);
}
if (call->state == AFS_CALL_COMPLETE) {
call->reply = NULL;
/* We have two refs to release - one from the alloc and one
* queued with the work item - and we can't just deallocate the
* call because the work item may be queued again.
*/
call->async_work.func = afs_delete_async_call;
if (!queue_work(afs_async_calls, &call->async_work))
afs_put_call(call);
}
afs_put_call(call);
_leave("");
}
static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
{
struct afs_call *call = (struct afs_call *)user_call_ID;
call->rxcall = rxcall;
}
/*
* Charge the incoming call preallocation.
*/
static void afs_charge_preallocation(struct work_struct *work)
{
struct afs_call *call = afs_spare_incoming_call;
for (;;) {
if (!call) {
call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
if (!call)
break;
call->async = true;
call->state = AFS_CALL_AWAIT_OP_ID;
init_waitqueue_head(&call->waitq);
}
if (rxrpc_kernel_charge_accept(afs_socket,
afs_wake_up_async_call,
afs_rx_attach,
(unsigned long)call,
GFP_KERNEL) < 0)
break;
call = NULL;
}
afs_spare_incoming_call = call;
}
/*
* Discard a preallocated call when a socket is shut down.
*/
static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
unsigned long user_call_ID)
{
struct afs_call *call = (struct afs_call *)user_call_ID;
call->rxcall = NULL;
afs_put_call(call);
}
/*
* Notification of an incoming call.
*/
static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long user_call_ID)
{
queue_work(afs_wq, &afs_charge_preallocation_work);
}
/*
* Grab the operation ID from an incoming cache manager call. The socket
* buffer is discarded on error or if we don't yet have sufficient data.
*/
static int afs_deliver_cm_op_id(struct afs_call *call)
{
int ret;
_enter("{%zu}", call->offset);
ASSERTCMP(call->offset, <, 4);
/* the operation ID forms the first four bytes of the request data */
ret = afs_extract_data(call, &call->tmp, 4, true);
if (ret < 0)
return ret;
call->operation_ID = ntohl(call->tmp);
call->state = AFS_CALL_AWAIT_REQUEST;
call->offset = 0;
/* ask the cache manager to route the call (it'll change the call type
* if successful) */
if (!afs_cm_incoming_call(call))
return -ENOTSUPP;
trace_afs_cb_call(call);
/* pass responsibility for the remainer of this message off to the
* cache manager op */
return call->type->deliver(call);
}
/*
* send an empty reply
*/
void afs_send_empty_reply(struct afs_call *call)
{
struct msghdr msg;
_enter("");
rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, 0);
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(afs_socket, call->rxcall, &msg, 0)) {
case 0:
_leave(" [replied]");
return;
case -ENOMEM:
_debug("oom");
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_USER_ABORT, -ENOMEM, "KOO");
default:
_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("");
rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, len);
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(afs_socket, call->rxcall, &msg, len);
if (n >= 0) {
/* Success */
_leave(" [replied]");
return;
}
if (n == -ENOMEM) {
_debug("oom");
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_USER_ABORT, -ENOMEM, "KOO");
}
_leave(" [error]");
}
/*
* Extract a piece of data from the received data socket buffers.
*/
int afs_extract_data(struct afs_call *call, void *buf, size_t count,
bool want_more)
{
int ret;
_enter("{%s,%zu},,%zu,%d",
call->type->name, call->offset, count, want_more);
ASSERTCMP(call->offset, <=, count);
ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
buf, count, &call->offset,
want_more, &call->abort_code);
trace_afs_recv_data(call, count, call->offset, want_more, ret);
if (ret == 0 || ret == -EAGAIN)
return ret;
if (ret == 1) {
switch (call->state) {
case AFS_CALL_AWAIT_REPLY:
call->state = AFS_CALL_COMPLETE;
break;
case AFS_CALL_AWAIT_REQUEST:
call->state = AFS_CALL_REPLYING;
break;
default:
break;
}
return 0;
}
if (ret == -ECONNABORTED)
call->error = call->type->abort_to_error(call->abort_code);
else
call->error = ret;
call->state = AFS_CALL_COMPLETE;
return ret;
}