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694 lines
18 KiB
694 lines
18 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* linux/fs/lockd/host.c |
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* |
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* Management for NLM peer hosts. The nlm_host struct is shared |
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* between client and server implementation. The only reason to |
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* do so is to reduce code bloat. |
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* |
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* Copyright (C) 1996, Olaf Kirch <[email protected]> |
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*/ |
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|
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#include <linux/types.h> |
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#include <linux/slab.h> |
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#include <linux/in.h> |
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#include <linux/in6.h> |
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#include <linux/sunrpc/clnt.h> |
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#include <linux/sunrpc/addr.h> |
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#include <linux/sunrpc/svc.h> |
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#include <linux/lockd/lockd.h> |
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#include <linux/mutex.h> |
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#include <linux/sunrpc/svc_xprt.h> |
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#include <net/ipv6.h> |
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#include "netns.h" |
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#define NLMDBG_FACILITY NLMDBG_HOSTCACHE |
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#define NLM_HOST_NRHASH 32 |
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#define NLM_HOST_REBIND (60 * HZ) |
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#define NLM_HOST_EXPIRE (300 * HZ) |
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#define NLM_HOST_COLLECT (120 * HZ) |
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static struct hlist_head nlm_server_hosts[NLM_HOST_NRHASH]; |
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static struct hlist_head nlm_client_hosts[NLM_HOST_NRHASH]; |
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|
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#define for_each_host(host, chain, table) \ |
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for ((chain) = (table); \ |
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(chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \ |
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hlist_for_each_entry((host), (chain), h_hash) |
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|
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#define for_each_host_safe(host, next, chain, table) \ |
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for ((chain) = (table); \ |
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(chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \ |
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hlist_for_each_entry_safe((host), (next), \ |
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(chain), h_hash) |
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|
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static unsigned long nrhosts; |
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static DEFINE_MUTEX(nlm_host_mutex); |
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|
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static void nlm_gc_hosts(struct net *net); |
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struct nlm_lookup_host_info { |
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const int server; /* search for server|client */ |
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const struct sockaddr *sap; /* address to search for */ |
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const size_t salen; /* it's length */ |
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const unsigned short protocol; /* transport to search for*/ |
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const u32 version; /* NLM version to search for */ |
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const char *hostname; /* remote's hostname */ |
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const size_t hostname_len; /* it's length */ |
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const int noresvport; /* use non-priv port */ |
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struct net *net; /* network namespace to bind */ |
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const struct cred *cred; |
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}; |
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/* |
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* Hash function must work well on big- and little-endian platforms |
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*/ |
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static unsigned int __nlm_hash32(const __be32 n) |
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{ |
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unsigned int hash = (__force u32)n ^ ((__force u32)n >> 16); |
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return hash ^ (hash >> 8); |
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} |
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static unsigned int __nlm_hash_addr4(const struct sockaddr *sap) |
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{ |
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const struct sockaddr_in *sin = (struct sockaddr_in *)sap; |
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return __nlm_hash32(sin->sin_addr.s_addr); |
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} |
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static unsigned int __nlm_hash_addr6(const struct sockaddr *sap) |
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{ |
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const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; |
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const struct in6_addr addr = sin6->sin6_addr; |
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return __nlm_hash32(addr.s6_addr32[0]) ^ |
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__nlm_hash32(addr.s6_addr32[1]) ^ |
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__nlm_hash32(addr.s6_addr32[2]) ^ |
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__nlm_hash32(addr.s6_addr32[3]); |
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} |
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static unsigned int nlm_hash_address(const struct sockaddr *sap) |
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{ |
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unsigned int hash; |
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switch (sap->sa_family) { |
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case AF_INET: |
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hash = __nlm_hash_addr4(sap); |
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break; |
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case AF_INET6: |
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hash = __nlm_hash_addr6(sap); |
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break; |
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default: |
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hash = 0; |
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} |
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return hash & (NLM_HOST_NRHASH - 1); |
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} |
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|
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/* |
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* Allocate and initialize an nlm_host. Common to both client and server. |
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*/ |
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static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni, |
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struct nsm_handle *nsm) |
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{ |
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struct nlm_host *host = NULL; |
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unsigned long now = jiffies; |
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if (nsm != NULL) |
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refcount_inc(&nsm->sm_count); |
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else { |
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host = NULL; |
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nsm = nsm_get_handle(ni->net, ni->sap, ni->salen, |
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ni->hostname, ni->hostname_len); |
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if (unlikely(nsm == NULL)) { |
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dprintk("lockd: %s failed; no nsm handle\n", |
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__func__); |
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goto out; |
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} |
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} |
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host = kmalloc(sizeof(*host), GFP_KERNEL); |
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if (unlikely(host == NULL)) { |
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dprintk("lockd: %s failed; no memory\n", __func__); |
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nsm_release(nsm); |
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goto out; |
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} |
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memcpy(nlm_addr(host), ni->sap, ni->salen); |
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host->h_addrlen = ni->salen; |
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rpc_set_port(nlm_addr(host), 0); |
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host->h_srcaddrlen = 0; |
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host->h_rpcclnt = NULL; |
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host->h_name = nsm->sm_name; |
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host->h_version = ni->version; |
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host->h_proto = ni->protocol; |
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host->h_reclaiming = 0; |
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host->h_server = ni->server; |
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host->h_noresvport = ni->noresvport; |
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host->h_inuse = 0; |
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init_waitqueue_head(&host->h_gracewait); |
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init_rwsem(&host->h_rwsem); |
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host->h_state = 0; |
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host->h_nsmstate = 0; |
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host->h_pidcount = 0; |
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refcount_set(&host->h_count, 1); |
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mutex_init(&host->h_mutex); |
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host->h_nextrebind = now + NLM_HOST_REBIND; |
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host->h_expires = now + NLM_HOST_EXPIRE; |
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INIT_LIST_HEAD(&host->h_lockowners); |
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spin_lock_init(&host->h_lock); |
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INIT_LIST_HEAD(&host->h_granted); |
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INIT_LIST_HEAD(&host->h_reclaim); |
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host->h_nsmhandle = nsm; |
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host->h_addrbuf = nsm->sm_addrbuf; |
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host->net = ni->net; |
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host->h_cred = get_cred(ni->cred); |
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strlcpy(host->nodename, utsname()->nodename, sizeof(host->nodename)); |
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out: |
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return host; |
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} |
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/* |
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* Destroy an nlm_host and free associated resources |
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* |
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* Caller must hold nlm_host_mutex. |
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*/ |
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static void nlm_destroy_host_locked(struct nlm_host *host) |
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{ |
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struct rpc_clnt *clnt; |
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struct lockd_net *ln = net_generic(host->net, lockd_net_id); |
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dprintk("lockd: destroy host %s\n", host->h_name); |
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hlist_del_init(&host->h_hash); |
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nsm_unmonitor(host); |
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nsm_release(host->h_nsmhandle); |
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clnt = host->h_rpcclnt; |
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if (clnt != NULL) |
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rpc_shutdown_client(clnt); |
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put_cred(host->h_cred); |
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kfree(host); |
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ln->nrhosts--; |
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nrhosts--; |
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} |
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/** |
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* nlmclnt_lookup_host - Find an NLM host handle matching a remote server |
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* @sap: network address of server |
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* @salen: length of server address |
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* @protocol: transport protocol to use |
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* @version: NLM protocol version |
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* @hostname: '\0'-terminated hostname of server |
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* @noresvport: 1 if non-privileged port should be used |
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* @net: pointer to net namespace |
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* @cred: pointer to cred |
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* |
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* Returns an nlm_host structure that matches the passed-in |
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* [server address, transport protocol, NLM version, server hostname]. |
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* If one doesn't already exist in the host cache, a new handle is |
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* created and returned. |
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*/ |
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struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap, |
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const size_t salen, |
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const unsigned short protocol, |
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const u32 version, |
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const char *hostname, |
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int noresvport, |
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struct net *net, |
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const struct cred *cred) |
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{ |
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struct nlm_lookup_host_info ni = { |
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.server = 0, |
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.sap = sap, |
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.salen = salen, |
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.protocol = protocol, |
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.version = version, |
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.hostname = hostname, |
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.hostname_len = strlen(hostname), |
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.noresvport = noresvport, |
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.net = net, |
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.cred = cred, |
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}; |
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struct hlist_head *chain; |
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struct nlm_host *host; |
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struct nsm_handle *nsm = NULL; |
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struct lockd_net *ln = net_generic(net, lockd_net_id); |
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dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__, |
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(hostname ? hostname : "<none>"), version, |
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(protocol == IPPROTO_UDP ? "udp" : "tcp")); |
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mutex_lock(&nlm_host_mutex); |
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chain = &nlm_client_hosts[nlm_hash_address(sap)]; |
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hlist_for_each_entry(host, chain, h_hash) { |
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if (host->net != net) |
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continue; |
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if (!rpc_cmp_addr(nlm_addr(host), sap)) |
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continue; |
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/* Same address. Share an NSM handle if we already have one */ |
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if (nsm == NULL) |
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nsm = host->h_nsmhandle; |
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if (host->h_proto != protocol) |
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continue; |
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if (host->h_version != version) |
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continue; |
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nlm_get_host(host); |
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dprintk("lockd: %s found host %s (%s)\n", __func__, |
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host->h_name, host->h_addrbuf); |
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goto out; |
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} |
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host = nlm_alloc_host(&ni, nsm); |
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if (unlikely(host == NULL)) |
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goto out; |
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hlist_add_head(&host->h_hash, chain); |
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ln->nrhosts++; |
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nrhosts++; |
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dprintk("lockd: %s created host %s (%s)\n", __func__, |
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host->h_name, host->h_addrbuf); |
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out: |
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mutex_unlock(&nlm_host_mutex); |
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return host; |
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} |
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/** |
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* nlmclnt_release_host - release client nlm_host |
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* @host: nlm_host to release |
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* |
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*/ |
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void nlmclnt_release_host(struct nlm_host *host) |
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{ |
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if (host == NULL) |
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return; |
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dprintk("lockd: release client host %s\n", host->h_name); |
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WARN_ON_ONCE(host->h_server); |
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if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) { |
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WARN_ON_ONCE(!list_empty(&host->h_lockowners)); |
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WARN_ON_ONCE(!list_empty(&host->h_granted)); |
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WARN_ON_ONCE(!list_empty(&host->h_reclaim)); |
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nlm_destroy_host_locked(host); |
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mutex_unlock(&nlm_host_mutex); |
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} |
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} |
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/** |
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* nlmsvc_lookup_host - Find an NLM host handle matching a remote client |
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* @rqstp: incoming NLM request |
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* @hostname: name of client host |
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* @hostname_len: length of client hostname |
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* |
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* Returns an nlm_host structure that matches the [client address, |
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* transport protocol, NLM version, client hostname] of the passed-in |
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* NLM request. If one doesn't already exist in the host cache, a |
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* new handle is created and returned. |
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* |
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* Before possibly creating a new nlm_host, construct a sockaddr |
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* for a specific source address in case the local system has |
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* multiple network addresses. The family of the address in |
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* rq_daddr is guaranteed to be the same as the family of the |
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* address in rq_addr, so it's safe to use the same family for |
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* the source address. |
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*/ |
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struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp, |
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const char *hostname, |
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const size_t hostname_len) |
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{ |
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struct hlist_head *chain; |
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struct nlm_host *host = NULL; |
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struct nsm_handle *nsm = NULL; |
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struct sockaddr *src_sap = svc_daddr(rqstp); |
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size_t src_len = rqstp->rq_daddrlen; |
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struct net *net = SVC_NET(rqstp); |
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struct nlm_lookup_host_info ni = { |
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.server = 1, |
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.sap = svc_addr(rqstp), |
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.salen = rqstp->rq_addrlen, |
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.protocol = rqstp->rq_prot, |
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.version = rqstp->rq_vers, |
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.hostname = hostname, |
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.hostname_len = hostname_len, |
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.net = net, |
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}; |
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struct lockd_net *ln = net_generic(net, lockd_net_id); |
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dprintk("lockd: %s(host='%.*s', vers=%u, proto=%s)\n", __func__, |
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(int)hostname_len, hostname, rqstp->rq_vers, |
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(rqstp->rq_prot == IPPROTO_UDP ? "udp" : "tcp")); |
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mutex_lock(&nlm_host_mutex); |
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if (time_after_eq(jiffies, ln->next_gc)) |
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nlm_gc_hosts(net); |
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chain = &nlm_server_hosts[nlm_hash_address(ni.sap)]; |
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hlist_for_each_entry(host, chain, h_hash) { |
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if (host->net != net) |
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continue; |
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if (!rpc_cmp_addr(nlm_addr(host), ni.sap)) |
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continue; |
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/* Same address. Share an NSM handle if we already have one */ |
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if (nsm == NULL) |
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nsm = host->h_nsmhandle; |
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if (host->h_proto != ni.protocol) |
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continue; |
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if (host->h_version != ni.version) |
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continue; |
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if (!rpc_cmp_addr(nlm_srcaddr(host), src_sap)) |
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continue; |
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/* Move to head of hash chain. */ |
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hlist_del(&host->h_hash); |
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hlist_add_head(&host->h_hash, chain); |
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nlm_get_host(host); |
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dprintk("lockd: %s found host %s (%s)\n", |
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__func__, host->h_name, host->h_addrbuf); |
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goto out; |
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} |
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host = nlm_alloc_host(&ni, nsm); |
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if (unlikely(host == NULL)) |
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goto out; |
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memcpy(nlm_srcaddr(host), src_sap, src_len); |
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host->h_srcaddrlen = src_len; |
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hlist_add_head(&host->h_hash, chain); |
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ln->nrhosts++; |
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nrhosts++; |
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refcount_inc(&host->h_count); |
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dprintk("lockd: %s created host %s (%s)\n", |
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__func__, host->h_name, host->h_addrbuf); |
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out: |
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mutex_unlock(&nlm_host_mutex); |
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return host; |
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} |
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/** |
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* nlmsvc_release_host - release server nlm_host |
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* @host: nlm_host to release |
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* |
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* Host is destroyed later in nlm_gc_host(). |
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*/ |
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void nlmsvc_release_host(struct nlm_host *host) |
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{ |
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if (host == NULL) |
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return; |
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dprintk("lockd: release server host %s\n", host->h_name); |
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WARN_ON_ONCE(!host->h_server); |
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refcount_dec(&host->h_count); |
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} |
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/* |
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* Create the NLM RPC client for an NLM peer |
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*/ |
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struct rpc_clnt * |
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nlm_bind_host(struct nlm_host *host) |
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{ |
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struct rpc_clnt *clnt; |
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dprintk("lockd: nlm_bind_host %s (%s)\n", |
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host->h_name, host->h_addrbuf); |
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/* Lock host handle */ |
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mutex_lock(&host->h_mutex); |
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|
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/* If we've already created an RPC client, check whether |
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* RPC rebind is required |
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*/ |
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if ((clnt = host->h_rpcclnt) != NULL) { |
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nlm_rebind_host(host); |
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} else { |
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unsigned long increment = nlmsvc_timeout; |
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struct rpc_timeout timeparms = { |
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.to_initval = increment, |
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.to_increment = increment, |
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.to_maxval = increment * 6UL, |
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.to_retries = 5U, |
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}; |
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struct rpc_create_args args = { |
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.net = host->net, |
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.protocol = host->h_proto, |
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.address = nlm_addr(host), |
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.addrsize = host->h_addrlen, |
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.timeout = &timeparms, |
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.servername = host->h_name, |
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.program = &nlm_program, |
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.version = host->h_version, |
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.authflavor = RPC_AUTH_UNIX, |
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.flags = (RPC_CLNT_CREATE_NOPING | |
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RPC_CLNT_CREATE_AUTOBIND | |
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RPC_CLNT_CREATE_REUSEPORT), |
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.cred = host->h_cred, |
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}; |
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/* |
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* lockd retries server side blocks automatically so we want |
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* those to be soft RPC calls. Client side calls need to be |
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* hard RPC tasks. |
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*/ |
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if (!host->h_server) |
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args.flags |= RPC_CLNT_CREATE_HARDRTRY; |
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if (host->h_noresvport) |
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args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; |
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if (host->h_srcaddrlen) |
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args.saddress = nlm_srcaddr(host); |
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clnt = rpc_create(&args); |
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if (!IS_ERR(clnt)) |
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host->h_rpcclnt = clnt; |
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else { |
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printk("lockd: couldn't create RPC handle for %s\n", host->h_name); |
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clnt = NULL; |
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} |
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} |
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mutex_unlock(&host->h_mutex); |
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return clnt; |
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} |
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|
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/** |
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* nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port |
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* @host: NLM host handle for peer |
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* |
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* This is not needed when using a connection-oriented protocol, such as TCP. |
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* The existing autobind mechanism is sufficient to force a rebind when |
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* required, e.g. on connection state transitions. |
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*/ |
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void |
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nlm_rebind_host(struct nlm_host *host) |
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{ |
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if (host->h_proto != IPPROTO_UDP) |
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return; |
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if (host->h_rpcclnt && time_after_eq(jiffies, host->h_nextrebind)) { |
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rpc_force_rebind(host->h_rpcclnt); |
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host->h_nextrebind = jiffies + NLM_HOST_REBIND; |
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} |
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} |
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/* |
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* Increment NLM host count |
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*/ |
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struct nlm_host * nlm_get_host(struct nlm_host *host) |
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{ |
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if (host) { |
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dprintk("lockd: get host %s\n", host->h_name); |
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refcount_inc(&host->h_count); |
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host->h_expires = jiffies + NLM_HOST_EXPIRE; |
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} |
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return host; |
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} |
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static struct nlm_host *next_host_state(struct hlist_head *cache, |
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struct nsm_handle *nsm, |
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const struct nlm_reboot *info) |
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{ |
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struct nlm_host *host; |
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struct hlist_head *chain; |
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|
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mutex_lock(&nlm_host_mutex); |
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for_each_host(host, chain, cache) { |
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if (host->h_nsmhandle == nsm |
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&& host->h_nsmstate != info->state) { |
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host->h_nsmstate = info->state; |
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host->h_state++; |
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|
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nlm_get_host(host); |
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mutex_unlock(&nlm_host_mutex); |
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return host; |
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} |
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} |
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mutex_unlock(&nlm_host_mutex); |
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return NULL; |
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} |
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|
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/** |
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* nlm_host_rebooted - Release all resources held by rebooted host |
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* @net: network namespace |
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* @info: pointer to decoded results of NLM_SM_NOTIFY call |
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* |
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* We were notified that the specified host has rebooted. Release |
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* all resources held by that peer. |
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*/ |
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void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info) |
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{ |
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struct nsm_handle *nsm; |
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struct nlm_host *host; |
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|
|
nsm = nsm_reboot_lookup(net, info); |
|
if (unlikely(nsm == NULL)) |
|
return; |
|
|
|
/* Mark all hosts tied to this NSM state as having rebooted. |
|
* We run the loop repeatedly, because we drop the host table |
|
* lock for this. |
|
* To avoid processing a host several times, we match the nsmstate. |
|
*/ |
|
while ((host = next_host_state(nlm_server_hosts, nsm, info)) != NULL) { |
|
nlmsvc_free_host_resources(host); |
|
nlmsvc_release_host(host); |
|
} |
|
while ((host = next_host_state(nlm_client_hosts, nsm, info)) != NULL) { |
|
nlmclnt_recovery(host); |
|
nlmclnt_release_host(host); |
|
} |
|
|
|
nsm_release(nsm); |
|
} |
|
|
|
static void nlm_complain_hosts(struct net *net) |
|
{ |
|
struct hlist_head *chain; |
|
struct nlm_host *host; |
|
|
|
if (net) { |
|
struct lockd_net *ln = net_generic(net, lockd_net_id); |
|
|
|
if (ln->nrhosts == 0) |
|
return; |
|
pr_warn("lockd: couldn't shutdown host module for net %x!\n", |
|
net->ns.inum); |
|
dprintk("lockd: %lu hosts left in net %x:\n", ln->nrhosts, |
|
net->ns.inum); |
|
} else { |
|
if (nrhosts == 0) |
|
return; |
|
printk(KERN_WARNING "lockd: couldn't shutdown host module!\n"); |
|
dprintk("lockd: %lu hosts left:\n", nrhosts); |
|
} |
|
|
|
for_each_host(host, chain, nlm_server_hosts) { |
|
if (net && host->net != net) |
|
continue; |
|
dprintk(" %s (cnt %d use %d exp %ld net %x)\n", |
|
host->h_name, refcount_read(&host->h_count), |
|
host->h_inuse, host->h_expires, host->net->ns.inum); |
|
} |
|
} |
|
|
|
void |
|
nlm_shutdown_hosts_net(struct net *net) |
|
{ |
|
struct hlist_head *chain; |
|
struct nlm_host *host; |
|
|
|
mutex_lock(&nlm_host_mutex); |
|
|
|
/* First, make all hosts eligible for gc */ |
|
dprintk("lockd: nuking all hosts in net %x...\n", |
|
net ? net->ns.inum : 0); |
|
for_each_host(host, chain, nlm_server_hosts) { |
|
if (net && host->net != net) |
|
continue; |
|
host->h_expires = jiffies - 1; |
|
if (host->h_rpcclnt) { |
|
rpc_shutdown_client(host->h_rpcclnt); |
|
host->h_rpcclnt = NULL; |
|
} |
|
} |
|
|
|
/* Then, perform a garbage collection pass */ |
|
nlm_gc_hosts(net); |
|
nlm_complain_hosts(net); |
|
mutex_unlock(&nlm_host_mutex); |
|
} |
|
|
|
/* |
|
* Shut down the hosts module. |
|
* Note that this routine is called only at server shutdown time. |
|
*/ |
|
void |
|
nlm_shutdown_hosts(void) |
|
{ |
|
dprintk("lockd: shutting down host module\n"); |
|
nlm_shutdown_hosts_net(NULL); |
|
} |
|
|
|
/* |
|
* Garbage collect any unused NLM hosts. |
|
* This GC combines reference counting for async operations with |
|
* mark & sweep for resources held by remote clients. |
|
*/ |
|
static void |
|
nlm_gc_hosts(struct net *net) |
|
{ |
|
struct hlist_head *chain; |
|
struct hlist_node *next; |
|
struct nlm_host *host; |
|
|
|
dprintk("lockd: host garbage collection for net %x\n", |
|
net ? net->ns.inum : 0); |
|
for_each_host(host, chain, nlm_server_hosts) { |
|
if (net && host->net != net) |
|
continue; |
|
host->h_inuse = 0; |
|
} |
|
|
|
/* Mark all hosts that hold locks, blocks or shares */ |
|
nlmsvc_mark_resources(net); |
|
|
|
for_each_host_safe(host, next, chain, nlm_server_hosts) { |
|
if (net && host->net != net) |
|
continue; |
|
if (host->h_inuse || time_before(jiffies, host->h_expires)) { |
|
dprintk("nlm_gc_hosts skipping %s " |
|
"(cnt %d use %d exp %ld net %x)\n", |
|
host->h_name, refcount_read(&host->h_count), |
|
host->h_inuse, host->h_expires, |
|
host->net->ns.inum); |
|
continue; |
|
} |
|
if (refcount_dec_if_one(&host->h_count)) |
|
nlm_destroy_host_locked(host); |
|
} |
|
|
|
if (net) { |
|
struct lockd_net *ln = net_generic(net, lockd_net_id); |
|
|
|
ln->next_gc = jiffies + NLM_HOST_COLLECT; |
|
} |
|
}
|
|
|