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linux/fs/afs/cmservice.c
David Howells 2067b2b3f4 afs: Fix the CB.ProbeUuid service handler to reply correctly 
Fix the service handler function for the CB.ProbeUuid RPC call so that it
replies in the correct manner - that is an empty reply for success and an
abort of 1 for failure.

Putting 0 or 1 in an integer in the body of the reply should result in the
fileserver throwing an RX_PROTOCOL_ERROR abort and discarding its record of
the client; older servers, however, don't necessarily check that all the
data got consumed, and so might incorrectly think that they got a positive
response and associate the client with the wrong host record.

If the client is incorrectly associated, this will result in callbacks
intended for a different client being delivered to this one and then, when
the other client connects and responds positively, all of the callback
promises meant for the client that issued the improper response will be
lost and it won't receive any further change notifications.

Fixes: 9396d496d7 ("afs: support the CB.ProbeUuid RPC op")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
2019-07-30 14:38:51 +01:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/* AFS Cache Manager Service
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/ip.h>
#include "internal.h"
#include "afs_cm.h"
#include "protocol_yfs.h"
static int afs_deliver_cb_init_call_back_state(struct afs_call *);
static int afs_deliver_cb_init_call_back_state3(struct afs_call *);
static int afs_deliver_cb_probe(struct afs_call *);
static int afs_deliver_cb_callback(struct afs_call *);
static int afs_deliver_cb_probe_uuid(struct afs_call *);
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *);
static void afs_cm_destructor(struct afs_call *);
static void SRXAFSCB_CallBack(struct work_struct *);
static void SRXAFSCB_InitCallBackState(struct work_struct *);
static void SRXAFSCB_Probe(struct work_struct *);
static void SRXAFSCB_ProbeUuid(struct work_struct *);
static void SRXAFSCB_TellMeAboutYourself(struct work_struct *);
static int afs_deliver_yfs_cb_callback(struct afs_call *);
#define CM_NAME(name) \
char afs_SRXCB##name##_name[] __tracepoint_string = \
"CB." #name
/*
* CB.CallBack operation type
*/
static CM_NAME(CallBack);
static const struct afs_call_type afs_SRXCBCallBack = {
.name = afs_SRXCBCallBack_name,
.deliver = afs_deliver_cb_callback,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_CallBack,
};
/*
* CB.InitCallBackState operation type
*/
static CM_NAME(InitCallBackState);
static const struct afs_call_type afs_SRXCBInitCallBackState = {
.name = afs_SRXCBInitCallBackState_name,
.deliver = afs_deliver_cb_init_call_back_state,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_InitCallBackState,
};
/*
* CB.InitCallBackState3 operation type
*/
static CM_NAME(InitCallBackState3);
static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
.name = afs_SRXCBInitCallBackState3_name,
.deliver = afs_deliver_cb_init_call_back_state3,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_InitCallBackState,
};
/*
* CB.Probe operation type
*/
static CM_NAME(Probe);
static const struct afs_call_type afs_SRXCBProbe = {
.name = afs_SRXCBProbe_name,
.deliver = afs_deliver_cb_probe,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_Probe,
};
/*
* CB.ProbeUuid operation type
*/
static CM_NAME(ProbeUuid);
static const struct afs_call_type afs_SRXCBProbeUuid = {
.name = afs_SRXCBProbeUuid_name,
.deliver = afs_deliver_cb_probe_uuid,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_ProbeUuid,
};
/*
* CB.TellMeAboutYourself operation type
*/
static CM_NAME(TellMeAboutYourself);
static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
.name = afs_SRXCBTellMeAboutYourself_name,
.deliver = afs_deliver_cb_tell_me_about_yourself,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_TellMeAboutYourself,
};
/*
* YFS CB.CallBack operation type
*/
static CM_NAME(YFS_CallBack);
static const struct afs_call_type afs_SRXYFSCB_CallBack = {
.name = afs_SRXCBYFS_CallBack_name,
.deliver = afs_deliver_yfs_cb_callback,
.destructor = afs_cm_destructor,
.work = SRXAFSCB_CallBack,
};
/*
* route an incoming cache manager call
* - return T if supported, F if not
*/
bool afs_cm_incoming_call(struct afs_call *call)
{
_enter("{%u, CB.OP %u}", call->service_id, call->operation_ID);
call->epoch = rxrpc_kernel_get_epoch(call->net->socket, call->rxcall);
switch (call->operation_ID) {
case CBCallBack:
call->type = &afs_SRXCBCallBack;
return true;
case CBInitCallBackState:
call->type = &afs_SRXCBInitCallBackState;
return true;
case CBInitCallBackState3:
call->type = &afs_SRXCBInitCallBackState3;
return true;
case CBProbe:
call->type = &afs_SRXCBProbe;
return true;
case CBProbeUuid:
call->type = &afs_SRXCBProbeUuid;
return true;
case CBTellMeAboutYourself:
call->type = &afs_SRXCBTellMeAboutYourself;
return true;
case YFSCBCallBack:
if (call->service_id != YFS_CM_SERVICE)
return false;
call->type = &afs_SRXYFSCB_CallBack;
return true;
default:
return false;
}
}
/*
* Record a probe to the cache manager from a server.
*/
static int afs_record_cm_probe(struct afs_call *call, struct afs_server *server)
{
_enter("");
if (test_bit(AFS_SERVER_FL_HAVE_EPOCH, &server->flags) &&
!test_bit(AFS_SERVER_FL_PROBING, &server->flags)) {
if (server->cm_epoch == call->epoch)
return 0;
if (!server->probe.said_rebooted) {
pr_notice("kAFS: FS rebooted %pU\n", &server->uuid);
server->probe.said_rebooted = true;
}
}
spin_lock(&server->probe_lock);
if (!test_bit(AFS_SERVER_FL_HAVE_EPOCH, &server->flags)) {
server->cm_epoch = call->epoch;
server->probe.cm_epoch = call->epoch;
goto out;
}
if (server->probe.cm_probed &&
call->epoch != server->probe.cm_epoch &&
!server->probe.said_inconsistent) {
pr_notice("kAFS: FS endpoints inconsistent %pU\n",
&server->uuid);
server->probe.said_inconsistent = true;
}
if (!server->probe.cm_probed || call->epoch == server->cm_epoch)
server->probe.cm_epoch = server->cm_epoch;
out:
server->probe.cm_probed = true;
spin_unlock(&server->probe_lock);
return 0;
}
/*
* Find the server record by peer address and record a probe to the cache
* manager from a server.
*/
static int afs_find_cm_server_by_peer(struct afs_call *call)
{
struct sockaddr_rxrpc srx;
struct afs_server *server;
rxrpc_kernel_get_peer(call->net->socket, call->rxcall, &srx);
server = afs_find_server(call->net, &srx);
if (!server) {
trace_afs_cm_no_server(call, &srx);
return 0;
}
call->server = server;
return afs_record_cm_probe(call, server);
}
/*
* Find the server record by server UUID and record a probe to the cache
* manager from a server.
*/
static int afs_find_cm_server_by_uuid(struct afs_call *call,
struct afs_uuid *uuid)
{
struct afs_server *server;
rcu_read_lock();
server = afs_find_server_by_uuid(call->net, call->request);
rcu_read_unlock();
if (!server) {
trace_afs_cm_no_server_u(call, call->request);
return 0;
}
call->server = server;
return afs_record_cm_probe(call, server);
}
/*
* Clean up a cache manager call.
*/
static void afs_cm_destructor(struct afs_call *call)
{
kfree(call->buffer);
call->buffer = NULL;
}
/*
* The server supplied a list of callbacks that it wanted to break.
*/
static void SRXAFSCB_CallBack(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
/* We need to break the callbacks before sending the reply as the
* server holds up change visibility till it receives our reply so as
* to maintain cache coherency.
*/
if (call->server) {
trace_afs_server(call->server, atomic_read(&call->server->usage),
afs_server_trace_callback);
afs_break_callbacks(call->server, call->count, call->request);
}
afs_send_empty_reply(call);
afs_put_call(call);
_leave("");
}
/*
* deliver request data to a CB.CallBack call
*/
static int afs_deliver_cb_callback(struct afs_call *call)
{
struct afs_callback_break *cb;
__be32 *bp;
int ret, loop;
_enter("{%u}", call->unmarshall);
switch (call->unmarshall) {
case 0:
afs_extract_to_tmp(call);
call->unmarshall++;
/* extract the FID array and its count in two steps */
/* fall through */
case 1:
_debug("extract FID count");
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
call->count = ntohl(call->tmp);
_debug("FID count: %u", call->count);
if (call->count > AFSCBMAX)
return afs_protocol_error(call, -EBADMSG,
afs_eproto_cb_fid_count);
call->buffer = kmalloc(array3_size(call->count, 3, 4),
GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
afs_extract_to_buf(call, call->count * 3 * 4);
call->unmarshall++;
/* Fall through */
case 2:
_debug("extract FID array");
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
_debug("unmarshall FID array");
call->request = kcalloc(call->count,
sizeof(struct afs_callback_break),
GFP_KERNEL);
if (!call->request)
return -ENOMEM;
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->fid.vid = ntohl(*bp++);
cb->fid.vnode = ntohl(*bp++);
cb->fid.unique = ntohl(*bp++);
}
afs_extract_to_tmp(call);
call->unmarshall++;
/* extract the callback array and its count in two steps */
/* fall through */
case 3:
_debug("extract CB count");
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
call->count2 = ntohl(call->tmp);
_debug("CB count: %u", call->count2);
if (call->count2 != call->count && call->count2 != 0)
return afs_protocol_error(call, -EBADMSG,
afs_eproto_cb_count);
call->_iter = &call->iter;
iov_iter_discard(&call->iter, READ, call->count2 * 3 * 4);
call->unmarshall++;
/* Fall through */
case 4:
_debug("extract discard %zu/%u",
iov_iter_count(&call->iter), call->count2 * 3 * 4);
ret = afs_extract_data(call, false);
if (ret < 0)
return ret;
call->unmarshall++;
case 5:
break;
}
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
return afs_find_cm_server_by_peer(call);
}
/*
* allow the fileserver to request callback state (re-)initialisation
*/
static void SRXAFSCB_InitCallBackState(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("{%p}", call->server);
if (call->server)
afs_init_callback_state(call->server);
afs_send_empty_reply(call);
afs_put_call(call);
_leave("");
}
/*
* deliver request data to a CB.InitCallBackState call
*/
static int afs_deliver_cb_init_call_back_state(struct afs_call *call)
{
int ret;
_enter("");
afs_extract_discard(call, 0);
ret = afs_extract_data(call, false);
if (ret < 0)
return ret;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
return afs_find_cm_server_by_peer(call);
}
/*
* deliver request data to a CB.InitCallBackState3 call
*/
static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
{
struct afs_uuid *r;
unsigned loop;
__be32 *b;
int ret;
_enter("");
_enter("{%u}", call->unmarshall);
switch (call->unmarshall) {
case 0:
call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
afs_extract_to_buf(call, 11 * sizeof(__be32));
call->unmarshall++;
/* Fall through */
case 1:
_debug("extract UUID");
ret = afs_extract_data(call, false);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall UUID");
call->request = kmalloc(sizeof(struct afs_uuid), GFP_KERNEL);
if (!call->request)
return -ENOMEM;
b = call->buffer;
r = call->request;
r->time_low = b[0];
r->time_mid = htons(ntohl(b[1]));
r->time_hi_and_version = htons(ntohl(b[2]));
r->clock_seq_hi_and_reserved = ntohl(b[3]);
r->clock_seq_low = ntohl(b[4]);
for (loop = 0; loop < 6; loop++)
r->node[loop] = ntohl(b[loop + 5]);
call->unmarshall++;
case 2:
break;
}
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
return afs_find_cm_server_by_uuid(call, call->request);
}
/*
* allow the fileserver to see if the cache manager is still alive
*/
static void SRXAFSCB_Probe(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
afs_send_empty_reply(call);
afs_put_call(call);
_leave("");
}
/*
* deliver request data to a CB.Probe call
*/
static int afs_deliver_cb_probe(struct afs_call *call)
{
int ret;
_enter("");
afs_extract_discard(call, 0);
ret = afs_extract_data(call, false);
if (ret < 0)
return ret;
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
return afs_find_cm_server_by_peer(call);
}
/*
* allow the fileserver to quickly find out if the fileserver has been rebooted
*/
static void SRXAFSCB_ProbeUuid(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
struct afs_uuid *r = call->request;
_enter("");
if (memcmp(r, &call->net->uuid, sizeof(call->net->uuid)) == 0)
afs_send_empty_reply(call);
else
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
1, 1, "K-1");
afs_put_call(call);
_leave("");
}
/*
* deliver request data to a CB.ProbeUuid call
*/
static int afs_deliver_cb_probe_uuid(struct afs_call *call)
{
struct afs_uuid *r;
unsigned loop;
__be32 *b;
int ret;
_enter("{%u}", call->unmarshall);
switch (call->unmarshall) {
case 0:
call->buffer = kmalloc_array(11, sizeof(__be32), GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
afs_extract_to_buf(call, 11 * sizeof(__be32));
call->unmarshall++;
/* Fall through */
case 1:
_debug("extract UUID");
ret = afs_extract_data(call, false);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall UUID");
call->request = kmalloc(sizeof(struct afs_uuid), GFP_KERNEL);
if (!call->request)
return -ENOMEM;
b = call->buffer;
r = call->request;
r->time_low = b[0];
r->time_mid = htons(ntohl(b[1]));
r->time_hi_and_version = htons(ntohl(b[2]));
r->clock_seq_hi_and_reserved = ntohl(b[3]);
r->clock_seq_low = ntohl(b[4]);
for (loop = 0; loop < 6; loop++)
r->node[loop] = ntohl(b[loop + 5]);
call->unmarshall++;
case 2:
break;
}
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
return afs_find_cm_server_by_uuid(call, call->request);
}
/*
* allow the fileserver to ask about the cache manager's capabilities
*/
static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
int loop;
struct {
struct /* InterfaceAddr */ {
__be32 nifs;
__be32 uuid[11];
__be32 ifaddr[32];
__be32 netmask[32];
__be32 mtu[32];
} ia;
struct /* Capabilities */ {
__be32 capcount;
__be32 caps[1];
} cap;
} reply;
_enter("");
memset(&reply, 0, sizeof(reply));
reply.ia.uuid[0] = call->net->uuid.time_low;
reply.ia.uuid[1] = htonl(ntohs(call->net->uuid.time_mid));
reply.ia.uuid[2] = htonl(ntohs(call->net->uuid.time_hi_and_version));
reply.ia.uuid[3] = htonl((s8) call->net->uuid.clock_seq_hi_and_reserved);
reply.ia.uuid[4] = htonl((s8) call->net->uuid.clock_seq_low);
for (loop = 0; loop < 6; loop++)
reply.ia.uuid[loop + 5] = htonl((s8) call->net->uuid.node[loop]);
reply.cap.capcount = htonl(1);
reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION);
afs_send_simple_reply(call, &reply, sizeof(reply));
afs_put_call(call);
_leave("");
}
/*
* deliver request data to a CB.TellMeAboutYourself call
*/
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
{
int ret;
_enter("");
afs_extract_discard(call, 0);
ret = afs_extract_data(call, false);
if (ret < 0)
return ret;
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
return afs_find_cm_server_by_peer(call);
}
/*
* deliver request data to a YFS CB.CallBack call
*/
static int afs_deliver_yfs_cb_callback(struct afs_call *call)
{
struct afs_callback_break *cb;
struct yfs_xdr_YFSFid *bp;
size_t size;
int ret, loop;
_enter("{%u}", call->unmarshall);
switch (call->unmarshall) {
case 0:
afs_extract_to_tmp(call);
call->unmarshall++;
/* extract the FID array and its count in two steps */
/* Fall through */
case 1:
_debug("extract FID count");
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
call->count = ntohl(call->tmp);
_debug("FID count: %u", call->count);
if (call->count > YFSCBMAX)
return afs_protocol_error(call, -EBADMSG,
afs_eproto_cb_fid_count);
size = array_size(call->count, sizeof(struct yfs_xdr_YFSFid));
call->buffer = kmalloc(size, GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
afs_extract_to_buf(call, size);
call->unmarshall++;
/* Fall through */
case 2:
_debug("extract FID array");
ret = afs_extract_data(call, false);
if (ret < 0)
return ret;
_debug("unmarshall FID array");
call->request = kcalloc(call->count,
sizeof(struct afs_callback_break),
GFP_KERNEL);
if (!call->request)
return -ENOMEM;
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->fid.vid = xdr_to_u64(bp->volume);
cb->fid.vnode = xdr_to_u64(bp->vnode.lo);
cb->fid.vnode_hi = ntohl(bp->vnode.hi);
cb->fid.unique = ntohl(bp->vnode.unique);
bp++;
}
afs_extract_to_tmp(call);
call->unmarshall++;
case 3:
break;
}
if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
return afs_io_error(call, afs_io_error_cm_reply);
/* We'll need the file server record as that tells us which set of
* vnodes to operate upon.
*/
return afs_find_cm_server_by_peer(call);
}
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