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/* * linux/fs/lockd/host.c * * Management for NLM peer hosts. The nlm_host struct is shared * between client and server implementation. The only reason to * do so is to reduce code bloat. * * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ #include <linux/types.h>#include <linux/slab.h>#include <linux/in.h>#include <linux/in6.h>#include <linux/sunrpc/clnt.h>#include <linux/sunrpc/svc.h>#include <linux/lockd/lockd.h>#include <linux/mutex.h> #include <linux/sunrpc/svc_xprt.h> #include <net/ipv6.h> #define NLMDBG_FACILITY		NLMDBG_HOSTCACHE#define NLM_HOST_NRHASH		32#define NLM_HOST_REBIND		(60 * HZ)#define NLM_HOST_EXPIRE		(300 * HZ)#define NLM_HOST_COLLECT	(120 * HZ) static struct hlist_head	nlm_server_hosts[NLM_HOST_NRHASH];static struct hlist_head	nlm_client_hosts[NLM_HOST_NRHASH]; #define for_each_host(host, pos, chain, table) \	for ((chain) = (table); \	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \		hlist_for_each_entry((host), (pos), (chain), h_hash) #define for_each_host_safe(host, pos, next, chain, table) \	for ((chain) = (table); \	     (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \		hlist_for_each_entry_safe((host), (pos), (next), \						(chain), h_hash) static unsigned long		next_gc;static unsigned long		nrhosts;static DEFINE_MUTEX(nlm_host_mutex); static void			nlm_gc_hosts(void); struct nlm_lookup_host_info {	const int		server;		/* search for server|client */	const struct sockaddr	*sap;		/* address to search for */	const size_t		salen;		/* it's length */	const unsigned short	protocol;	/* transport to search for*/	const u32		version;	/* NLM version to search for */	const char		*hostname;	/* remote's hostname */	const size_t		hostname_len;	/* it's length */	const int		noresvport;	/* use non-priv port */	struct net		*net;		/* network namespace to bind */}; /* * Hash function must work well on big- and little-endian platforms */static unsigned int __nlm_hash32(const __be32 n){	unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16);	return hash ^ (hash >> 8);} static unsigned int __nlm_hash_addr4(const struct sockaddr *sap){	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;	return __nlm_hash32(sin->sin_addr.s_addr);} static unsigned int __nlm_hash_addr6(const struct sockaddr *sap){	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;	const struct in6_addr addr = sin6->sin6_addr;	return __nlm_hash32(addr.s6_addr32[0]) ^	       __nlm_hash32(addr.s6_addr32[1]) ^	       __nlm_hash32(addr.s6_addr32[2]) ^	       __nlm_hash32(addr.s6_addr32[3]);} static unsigned int nlm_hash_address(const struct sockaddr *sap){	unsigned int hash; 	switch (sap->sa_family) {	case AF_INET:		hash = __nlm_hash_addr4(sap);		break;	case AF_INET6:		hash = __nlm_hash_addr6(sap);		break;	default:		hash = 0;	}	return hash & (NLM_HOST_NRHASH - 1);} /* * Allocate and initialize an nlm_host.  Common to both client and server. */static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni,				       struct nsm_handle *nsm){	struct nlm_host *host = NULL;	unsigned long now = jiffies; 	if (nsm != NULL)		atomic_inc(&nsm->sm_count);	else {		host = NULL;		nsm = nsm_get_handle(ni->sap, ni->salen,					ni->hostname, ni->hostname_len);		if (unlikely(nsm == NULL)) {			dprintk("lockd: %s failed; no nsm handle\n",				__func__);			goto out;		}	} 	host = kmalloc(sizeof(*host), GFP_KERNEL);	if (unlikely(host == NULL)) {		dprintk("lockd: %s failed; no memory\n", __func__);		nsm_release(nsm);		goto out;	} 	memcpy(nlm_addr(host), ni->sap, ni->salen);	host->h_addrlen    = ni->salen;	rpc_set_port(nlm_addr(host), 0);	host->h_srcaddrlen = 0; 	host->h_rpcclnt    = NULL;	host->h_name	   = nsm->sm_name;	host->h_version    = ni->version;	host->h_proto      = ni->protocol;	host->h_reclaiming = 0;	host->h_server     = ni->server;	host->h_noresvport = ni->noresvport;	host->h_inuse      = 0;	init_waitqueue_head(&host->h_gracewait);	init_rwsem(&host->h_rwsem);	host->h_state      = 0;	host->h_nsmstate   = 0;	host->h_pidcount   = 0;	atomic_set(&host->h_count, 1);	mutex_init(&host->h_mutex);	host->h_nextrebind = now + NLM_HOST_REBIND;	host->h_expires    = now + NLM_HOST_EXPIRE;	INIT_LIST_HEAD(&host->h_lockowners);	spin_lock_init(&host->h_lock);	INIT_LIST_HEAD(&host->h_granted);	INIT_LIST_HEAD(&host->h_reclaim);	host->h_nsmhandle  = nsm;	host->h_addrbuf    = nsm->sm_addrbuf;	host->net	   = ni->net; out:	return host;} /* * Destroy an nlm_host and free associated resources * * Caller must hold nlm_host_mutex. */static void nlm_destroy_host_locked(struct nlm_host *host){	struct rpc_clnt	*clnt; 	dprintk("lockd: destroy host %s\n", host->h_name); 	BUG_ON(!list_empty(&host->h_lockowners));	BUG_ON(atomic_read(&host->h_count)); 	hlist_del_init(&host->h_hash); 	nsm_unmonitor(host);	nsm_release(host->h_nsmhandle); 	clnt = host->h_rpcclnt;	if (clnt != NULL)		rpc_shutdown_client(clnt);	kfree(host); 	nrhosts--;} /** * nlmclnt_lookup_host - Find an NLM host handle matching a remote server * @sap: network address of server * @salen: length of server address * @protocol: transport protocol to use * @version: NLM protocol version * @hostname: '\0'-terminated hostname of server * @noresvport: 1 if non-privileged port should be used * * Returns an nlm_host structure that matches the passed-in * [server address, transport protocol, NLM version, server hostname]. * If one doesn't already exist in the host cache, a new handle is * created and returned. */struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,				     const size_t salen,				     const unsigned short protocol,				     const u32 version,				     const char *hostname,				     int noresvport,				     struct net *net){	struct nlm_lookup_host_info ni = {		.server		= 0,		.sap		= sap,		.salen		= salen,		.protocol	= protocol,		.version	= version,		.hostname	= hostname,		.hostname_len	= strlen(hostname),		.noresvport	= noresvport,		.net		= net,	};	struct hlist_head *chain;	struct hlist_node *pos;	struct nlm_host	*host;	struct nsm_handle *nsm = NULL; 	dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,			(hostname ? hostname : "<none>"), version,			(protocol == IPPROTO_UDP ? "udp" : "tcp")); 	mutex_lock(&nlm_host_mutex); 	chain = &nlm_client_hosts[nlm_hash_address(sap)];	hlist_for_each_entry(host, pos, chain, h_hash) {		if (host->net != net)			continue;		if (!rpc_cmp_addr(nlm_addr(host), sap))			continue; 		/* Same address. Share an NSM handle if we already have one */		if (nsm == NULL)			nsm = host->h_nsmhandle; 		if (host->h_proto != protocol)			continue;		if (host->h_version != version)			continue; 		nlm_get_host(host);		dprintk("lockd: %s found host %s (%s)\n", __func__,			host->h_name, host->h_addrbuf);		goto out;	} 	host = nlm_alloc_host(&ni, nsm);	if (unlikely(host == NULL))		goto out; 	hlist_add_head(&host->h_hash, chain);	nrhosts++; 	dprintk("lockd: %s created host %s (%s)\n", __func__,		host->h_name, host->h_addrbuf); out:	mutex_unlock(&nlm_host_mutex);	return host;} /** * nlmclnt_release_host - release client nlm_host * @host: nlm_host to release * */void nlmclnt_release_host(struct nlm_host *host){	if (host == NULL)		return; 	dprintk("lockd: release client host %s\n", host->h_name); 	BUG_ON(atomic_read(&host->h_count) < 0);	BUG_ON(host->h_server); 	if (atomic_dec_and_test(&host->h_count)) {		BUG_ON(!list_empty(&host->h_lockowners));		BUG_ON(!list_empty(&host->h_granted));		BUG_ON(!list_empty(&host->h_reclaim)); 		mutex_lock(&nlm_host_mutex);		nlm_destroy_host_locked(host);		mutex_unlock(&nlm_host_mutex);	}} /** * nlmsvc_lookup_host - Find an NLM host handle matching a remote client * @rqstp: incoming NLM request * @hostname: name of client host * @hostname_len: length of client hostname * * Returns an nlm_host structure that matches the [client address, * transport protocol, NLM version, client hostname] of the passed-in * NLM request.  If one doesn't already exist in the host cache, a * new handle is created and returned. * * Before possibly creating a new nlm_host, construct a sockaddr * for a specific source address in case the local system has * multiple network addresses.  The family of the address in * rq_daddr is guaranteed to be the same as the family of the * address in rq_addr, so it's safe to use the same family for * the source address. */struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp,				    const char *hostname,				    const size_t hostname_len){	struct hlist_head *chain;	struct hlist_node *pos;	struct nlm_host	*host = NULL;	struct nsm_handle *nsm = NULL;	struct sockaddr *src_sap = svc_daddr(rqstp);	size_t src_len = rqstp->rq_daddrlen;	struct net *net = rqstp->rq_xprt->xpt_net;	struct nlm_lookup_host_info ni = {		.server		= 1,		.sap		= svc_addr(rqstp),		.salen		= rqstp->rq_addrlen,		.protocol	= rqstp->rq_prot,		.version	= rqstp->rq_vers,		.hostname	= hostname,		.hostname_len	= hostname_len,		.net		= net,	}; 	dprintk("lockd: %s(host='%*s', vers=%u, proto=%s)\n", __func__,			(int)hostname_len, hostname, rqstp->rq_vers,			(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp")); 	mutex_lock(&nlm_host_mutex); 	if (time_after_eq(jiffies, next_gc))		nlm_gc_hosts(); 	chain = &nlm_server_hosts[nlm_hash_address(ni.sap)];	hlist_for_each_entry(host, pos, chain, h_hash) {		if (host->net != net)			continue;		if (!rpc_cmp_addr(nlm_addr(host), ni.sap))			continue; 		/* Same address. Share an NSM handle if we already have one */		if (nsm == NULL)			nsm = host->h_nsmhandle; 		if (host->h_proto != ni.protocol)			continue;		if (host->h_version != ni.version)			continue;		if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap))			continue; 		/* Move to head of hash chain. */		hlist_del(&host->h_hash);		hlist_add_head(&host->h_hash, chain); 		nlm_get_host(host);		dprintk("lockd: %s found host %s (%s)\n",			__func__, host->h_name, host->h_addrbuf);		goto out;	} 	host = nlm_alloc_host(&ni, nsm);	if (unlikely(host == NULL))		goto out; 	memcpy(nlm_srcaddr(host), src_sap, src_len);	host->h_srcaddrlen = src_len;	hlist_add_head(&host->h_hash, chain);	nrhosts++; 	dprintk("lockd: %s created host %s (%s)\n",		__func__, host->h_name, host->h_addrbuf); out:	mutex_unlock(&nlm_host_mutex);	return host;} /** * nlmsvc_release_host - release server nlm_host * @host: nlm_host to release * * Host is destroyed later in nlm_gc_host(). */void nlmsvc_release_host(struct nlm_host *host){	if (host == NULL)		return; 	dprintk("lockd: release server host %s\n", host->h_name); 	BUG_ON(atomic_read(&host->h_count) < 0);	BUG_ON(!host->h_server);	atomic_dec(&host->h_count);} /* * Create the NLM RPC client for an NLM peer */struct rpc_clnt *nlm_bind_host(struct nlm_host *host){	struct rpc_clnt	*clnt; 	dprintk("lockd: nlm_bind_host %s (%s)\n",			host->h_name, host->h_addrbuf); 	/* Lock host handle */	mutex_lock(&host->h_mutex); 	/* If we've already created an RPC client, check whether	 * RPC rebind is required	 */	if ((clnt = host->h_rpcclnt) != NULL) {		if (time_after_eq(jiffies, host->h_nextrebind)) {			rpc_force_rebind(clnt);			host->h_nextrebind = jiffies + NLM_HOST_REBIND;			dprintk("lockd: next rebind in %lu jiffies\n",					host->h_nextrebind - jiffies);		}	} else {		unsigned long increment = nlmsvc_timeout;		struct rpc_timeout timeparms = {			.to_initval	= increment,			.to_increment	= increment,			.to_maxval	= increment * 6UL,			.to_retries	= 5U,		};		struct rpc_create_args args = {			.net		= host->net,			.protocol	= host->h_proto,			.address	= nlm_addr(host),			.addrsize	= host->h_addrlen,			.timeout	= &timeparms,			.servername	= host->h_name,			.program	= &nlm_program,			.version	= host->h_version,			.authflavor	= RPC_AUTH_UNIX,			.flags		= (RPC_CLNT_CREATE_NOPING |					   RPC_CLNT_CREATE_AUTOBIND),		}; 		/*		 * lockd retries server side blocks automatically so we want		 * those to be soft RPC calls. Client side calls need to be		 * hard RPC tasks.		 */		if (!host->h_server)			args.flags |= RPC_CLNT_CREATE_HARDRTRY;		if (host->h_noresvport)			args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;		if (host->h_srcaddrlen)			args.saddress = nlm_srcaddr(host); 		clnt = rpc_create(&args);		if (!IS_ERR(clnt))			host->h_rpcclnt = clnt;		else {			printk("lockd: couldn't create RPC handle for %s\n", host->h_name);			clnt = NULL;		}	} 	mutex_unlock(&host->h_mutex);	return clnt;} /* * Force a portmap lookup of the remote lockd port */voidnlm_rebind_host(struct nlm_host *host){	dprintk("lockd: rebind host %s\n", host->h_name);	if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) {		rpc_force_rebind(host->h_rpcclnt);		host->h_nextrebind = jiffies + NLM_HOST_REBIND;	}} /* * Increment NLM host count */struct nlm_host * nlm_get_host(struct nlm_host *host)

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