/* * 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/smp_lock.h>#include <linux/sunrpc/svc.h>#include <linux/sunrpc/svcsock.h>#include <linux/nfs_fs.h>#include <linux/mutex.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;	pid_t pid;	struct completion started;	struct completion stopped;}; static struct nfs_callback_data nfs_callback_info;static DEFINE_MUTEX(nfs_callback_mutex);static struct svc_program nfs4_callback_program; unsigned int nfs_callback_set_tcpport;unsigned short nfs_callback_tcpport;static const int nfs_set_port_min = 0;static const int nfs_set_port_max = 65535; static int param_set_port(const char *val, struct kernel_param *kp){	char *endp;	int num = simple_strtol(val, &endp, 0);	if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)		return -EINVAL;	*((int *)kp->arg) = num;	return 0;} module_param_call(callback_tcpport, param_set_port, param_get_int,		 &nfs_callback_set_tcpport, 0644); /* * This is the callback kernel thread. */static void nfs_callback_svc(struct svc_rqst *rqstp){	int err; 	__module_get(THIS_MODULE);	lock_kernel(); 	nfs_callback_info.pid = current->pid;	daemonize("nfsv4-svc");	/* Process request with signals blocked, but allow SIGKILL.  */	allow_signal(SIGKILL); 	complete(&nfs_callback_info.started); 	for(;;) {		char buf[RPC_MAX_ADDRBUFLEN]; 		if (signalled()) {			if (nfs_callback_info.users == 0)				break;			flush_signals(current);		}		/*		 * Listen for a request on the socket		 */		err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);		if (err == -EAGAIN || err == -EINTR)			continue;		if (err < 0) {			printk(KERN_WARNING					"%s: terminating on error %d\n",					__FUNCTION__, -err);			break;		}		dprintk("%s: request from %s\n", __FUNCTION__,				svc_print_addr(rqstp, buf, sizeof(buf)));		svc_process(rqstp);	} 	svc_exit_thread(rqstp);	nfs_callback_info.pid = 0;	complete(&nfs_callback_info.stopped);	unlock_kernel();	module_put_and_exit(0);} /* * Bring up the server process if it is not already up. */int nfs_callback_up(void){	struct svc_serv *serv;	int ret = 0; 	lock_kernel();	mutex_lock(&nfs_callback_mutex);	if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)		goto out;	init_completion(&nfs_callback_info.started);	init_completion(&nfs_callback_info.stopped);	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);	ret = -ENOMEM;	if (!serv)		goto out_err; 	ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,							SVC_SOCK_ANONYMOUS);	if (ret <= 0)		goto out_destroy;	nfs_callback_tcpport = ret;	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport); 	ret = svc_create_thread(nfs_callback_svc, serv);	if (ret < 0)		goto out_destroy;	nfs_callback_info.serv = serv;	wait_for_completion(&nfs_callback_info.started);out:	mutex_unlock(&nfs_callback_mutex);	unlock_kernel();	return ret;out_destroy:	dprintk("Couldn't create callback socket or server thread; err = %d\n",		ret);	svc_destroy(serv);out_err:	nfs_callback_info.users--;	goto out;} /* * Kill the server process if it is not already up. */void nfs_callback_down(void){	lock_kernel();	mutex_lock(&nfs_callback_mutex);	nfs_callback_info.users--;	do {		if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)			break;		if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)			break;	} while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);	mutex_unlock(&nfs_callback_mutex);	unlock_kernel();} static int nfs_callback_authenticate(struct svc_rqst *rqstp){	struct sockaddr_in *addr = svc_addr_in(rqstp);	struct nfs_client *clp;	char buf[RPC_MAX_ADDRBUFLEN]; 	/* Don't talk to strangers */	clp = nfs_find_client(addr, 4);	if (clp == NULL)		return SVC_DROP; 	dprintk("%s: %s NFSv4 callback!\n", __FUNCTION__,			svc_print_addr(rqstp, buf, sizeof(buf)));	nfs_put_client(clp); 	switch (rqstp->rq_authop->flavour) {		case RPC_AUTH_NULL:			if (rqstp->rq_proc != CB_NULL)				return SVC_DENIED;			break;		case RPC_AUTH_UNIX:			break;		case RPC_AUTH_GSS:			/* FIXME: RPCSEC_GSS handling? */		default:			return SVC_DENIED;	}	return SVC_OK;} /* * Define NFS4 callback program */static struct svc_version *nfs4_callback_version[] = {	[1] = &nfs4_callback_version1,}; 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,};