linux/fs/nfs/callback.c
Stanislav Kinsbursky 12918b10d5 NFS: hard-code init_net for NFS callback transports
In case of destroying mount namespace on child reaper exit, nsproxy is zeroed
to the point already. So, dereferencing of it is invalid.
This patch hard-code "init_net" for all network namespace references for NFS
callback services. This will be fixed with proper NFS callback
containerization.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-06-14 13:53:43 -04:00

413 lines
10 KiB
C

/*
* linux/fs/nfs/callback.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFSv4 callback handling
*/
#include <linux/completion.h>
#include <linux/ip.h>
#include <linux/module.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfs_fs.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/bc_xprt.h>
#include <net/inet_sock.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_CALLBACK
struct nfs_callback_data {
unsigned int users;
struct svc_serv *serv;
struct svc_rqst *rqst;
struct task_struct *task;
};
static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
static DEFINE_MUTEX(nfs_callback_mutex);
static struct svc_program nfs4_callback_program;
unsigned int nfs_callback_set_tcpport;
unsigned short nfs_callback_tcpport;
unsigned short nfs_callback_tcpport6;
#define NFS_CALLBACK_MAXPORTNR (65535U)
static int param_set_portnr(const char *val, const struct kernel_param *kp)
{
unsigned long num;
int ret;
if (!val)
return -EINVAL;
ret = strict_strtoul(val, 0, &num);
if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
return -EINVAL;
*((unsigned int *)kp->arg) = num;
return 0;
}
static struct kernel_param_ops param_ops_portnr = {
.set = param_set_portnr,
.get = param_get_uint,
};
#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
/*
* This is the NFSv4 callback kernel thread.
*/
static int
nfs4_callback_svc(void *vrqstp)
{
int err, preverr = 0;
struct svc_rqst *rqstp = vrqstp;
set_freezable();
while (!kthread_should_stop()) {
/*
* Listen for a request on the socket
*/
err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
if (err == -EAGAIN || err == -EINTR) {
preverr = err;
continue;
}
if (err < 0) {
if (err != preverr) {
printk(KERN_WARNING "NFS: %s: unexpected error "
"from svc_recv (%d)\n", __func__, err);
preverr = err;
}
schedule_timeout_uninterruptible(HZ);
continue;
}
preverr = err;
svc_process(rqstp);
}
return 0;
}
/*
* Prepare to bring up the NFSv4 callback service
*/
static struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
{
int ret;
ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret <= 0)
goto out_err;
nfs_callback_tcpport = ret;
dprintk("NFS: Callback listener port = %u (af %u)\n",
nfs_callback_tcpport, PF_INET);
ret = svc_create_xprt(serv, "tcp", &init_net, PF_INET6,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret > 0) {
nfs_callback_tcpport6 = ret;
dprintk("NFS: Callback listener port = %u (af %u)\n",
nfs_callback_tcpport6, PF_INET6);
} else if (ret == -EAFNOSUPPORT)
ret = 0;
else
goto out_err;
return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
out_err:
if (ret == 0)
ret = -ENOMEM;
return ERR_PTR(ret);
}
#if defined(CONFIG_NFS_V4_1)
/*
* The callback service for NFSv4.1 callbacks
*/
static int
nfs41_callback_svc(void *vrqstp)
{
struct svc_rqst *rqstp = vrqstp;
struct svc_serv *serv = rqstp->rq_server;
struct rpc_rqst *req;
int error;
DEFINE_WAIT(wq);
set_freezable();
while (!kthread_should_stop()) {
prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
spin_lock_bh(&serv->sv_cb_lock);
if (!list_empty(&serv->sv_cb_list)) {
req = list_first_entry(&serv->sv_cb_list,
struct rpc_rqst, rq_bc_list);
list_del(&req->rq_bc_list);
spin_unlock_bh(&serv->sv_cb_lock);
dprintk("Invoking bc_svc_process()\n");
error = bc_svc_process(serv, req, rqstp);
dprintk("bc_svc_process() returned w/ error code= %d\n",
error);
} else {
spin_unlock_bh(&serv->sv_cb_lock);
schedule();
}
finish_wait(&serv->sv_cb_waitq, &wq);
}
return 0;
}
/*
* Bring up the NFSv4.1 callback service
*/
static struct svc_rqst *
nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
{
struct svc_rqst *rqstp;
int ret;
/*
* Create an svc_sock for the back channel service that shares the
* fore channel connection.
* Returns the input port (0) and sets the svc_serv bc_xprt on success
*/
ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
SVC_SOCK_ANONYMOUS);
if (ret < 0) {
rqstp = ERR_PTR(ret);
goto out;
}
/*
* Save the svc_serv in the transport so that it can
* be referenced when the session backchannel is initialized
*/
xprt->bc_serv = serv;
INIT_LIST_HEAD(&serv->sv_cb_list);
spin_lock_init(&serv->sv_cb_lock);
init_waitqueue_head(&serv->sv_cb_waitq);
rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
if (IS_ERR(rqstp)) {
svc_xprt_put(serv->sv_bc_xprt);
serv->sv_bc_xprt = NULL;
}
out:
dprintk("--> %s return %ld\n", __func__,
IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
return rqstp;
}
static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
struct svc_serv *serv, struct rpc_xprt *xprt,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
if (minorversion) {
*rqstpp = nfs41_callback_up(serv, xprt);
*callback_svc = nfs41_callback_svc;
}
return minorversion;
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct nfs_callback_data *cb_info)
{
if (minorversion)
xprt->bc_serv = cb_info->serv;
}
#else
static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
struct svc_serv *serv, struct rpc_xprt *xprt,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
return 0;
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct nfs_callback_data *cb_info)
{
}
#endif /* CONFIG_NFS_V4_1 */
/*
* Bring up the callback thread if it is not already up.
*/
int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
{
struct svc_serv *serv = NULL;
struct svc_rqst *rqstp;
int (*callback_svc)(void *vrqstp);
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
char svc_name[12];
int ret = 0;
int minorversion_setup;
struct net *net = &init_net;
mutex_lock(&nfs_callback_mutex);
if (cb_info->users++ || cb_info->task != NULL) {
nfs_callback_bc_serv(minorversion, xprt, cb_info);
goto out;
}
serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
if (!serv) {
ret = -ENOMEM;
goto out_err;
}
ret = svc_bind(serv, net);
if (ret < 0) {
printk(KERN_WARNING "NFS: bind callback service failed\n");
goto out_err;
}
minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
serv, xprt, &rqstp, &callback_svc);
if (!minorversion_setup) {
/* v4.0 callback setup */
rqstp = nfs4_callback_up(serv, xprt);
callback_svc = nfs4_callback_svc;
}
if (IS_ERR(rqstp)) {
ret = PTR_ERR(rqstp);
goto out_err;
}
svc_sock_update_bufs(serv);
sprintf(svc_name, "nfsv4.%u-svc", minorversion);
cb_info->serv = serv;
cb_info->rqst = rqstp;
cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
if (IS_ERR(cb_info->task)) {
ret = PTR_ERR(cb_info->task);
svc_exit_thread(cb_info->rqst);
cb_info->rqst = NULL;
cb_info->task = NULL;
goto out_err;
}
out:
/*
* svc_create creates the svc_serv with sv_nrthreads == 1, and then
* svc_prepare_thread increments that. So we need to call svc_destroy
* on both success and failure so that the refcount is 1 when the
* thread exits.
*/
if (serv)
svc_destroy(serv);
mutex_unlock(&nfs_callback_mutex);
return ret;
out_err:
dprintk("NFS: Couldn't create callback socket or server thread; "
"err = %d\n", ret);
cb_info->users--;
if (serv)
svc_shutdown_net(serv, net);
goto out;
}
/*
* Kill the callback thread if it's no longer being used.
*/
void nfs_callback_down(int minorversion)
{
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
mutex_lock(&nfs_callback_mutex);
cb_info->users--;
if (cb_info->users == 0 && cb_info->task != NULL) {
kthread_stop(cb_info->task);
svc_shutdown_net(cb_info->serv, &init_net);
svc_exit_thread(cb_info->rqst);
cb_info->serv = NULL;
cb_info->rqst = NULL;
cb_info->task = NULL;
}
mutex_unlock(&nfs_callback_mutex);
}
/* Boolean check of RPC_AUTH_GSS principal */
int
check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
{
char *p = rqstp->rq_cred.cr_principal;
if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
return 1;
/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
if (clp->cl_minorversion != 0)
return 0;
/*
* It might just be a normal user principal, in which case
* userspace won't bother to tell us the name at all.
*/
if (p == NULL)
return 0;
/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
if (memcmp(p, "nfs@", 4) != 0)
return 0;
p += 4;
if (strcmp(p, clp->cl_hostname) != 0)
return 0;
return 1;
}
/*
* pg_authenticate method for nfsv4 callback threads.
*
* The authflavor has been negotiated, so an incorrect flavor is a server
* bug. Drop packets with incorrect authflavor.
*
* All other checking done after NFS decoding where the nfs_client can be
* found in nfs4_callback_compound
*/
static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
switch (rqstp->rq_authop->flavour) {
case RPC_AUTH_NULL:
if (rqstp->rq_proc != CB_NULL)
return SVC_DROP;
break;
case RPC_AUTH_GSS:
/* No RPC_AUTH_GSS support yet in NFSv4.1 */
if (svc_is_backchannel(rqstp))
return SVC_DROP;
}
return SVC_OK;
}
/*
* Define NFS4 callback program
*/
static struct svc_version *nfs4_callback_version[] = {
[1] = &nfs4_callback_version1,
[4] = &nfs4_callback_version4,
};
static struct svc_stat nfs4_callback_stats;
static struct svc_program nfs4_callback_program = {
.pg_prog = NFS4_CALLBACK, /* RPC service number */
.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
.pg_vers = nfs4_callback_version, /* version table */
.pg_name = "NFSv4 callback", /* service name */
.pg_class = "nfs", /* authentication class */
.pg_stats = &nfs4_callback_stats,
.pg_authenticate = nfs_callback_authenticate,
};