| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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/addr.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> |
| |
| #include "netns.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, chain, table) \ |
| for ((chain) = (table); \ |
| (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \ |
| hlist_for_each_entry((host), (chain), h_hash) |
| |
| #define for_each_host_safe(host, next, chain, table) \ |
| for ((chain) = (table); \ |
| (chain) < (table) + NLM_HOST_NRHASH; ++(chain)) \ |
| hlist_for_each_entry_safe((host), (next), \ |
| (chain), h_hash) |
| |
| static unsigned long nrhosts; |
| static DEFINE_MUTEX(nlm_host_mutex); |
| |
| static void nlm_gc_hosts(struct net *net); |
| |
| 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 */ |
| const struct cred *cred; |
| }; |
| |
| /* |
| * 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) |
| refcount_inc(&nsm->sm_count); |
| else { |
| host = NULL; |
| nsm = nsm_get_handle(ni->net, 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; |
| refcount_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; |
| host->h_cred = get_cred(ni->cred), |
| strlcpy(host->nodename, utsname()->nodename, sizeof(host->nodename)); |
| |
| 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; |
| struct lockd_net *ln = net_generic(host->net, lockd_net_id); |
| |
| dprintk("lockd: destroy host %s\n", host->h_name); |
| |
| 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); |
| put_cred(host->h_cred); |
| kfree(host); |
| |
| ln->nrhosts--; |
| 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 |
| * @net: pointer to net namespace |
| * @cred: pointer to cred |
| * |
| * 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, |
| const struct cred *cred) |
| { |
| 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, |
| .cred = cred, |
| }; |
| struct hlist_head *chain; |
| struct nlm_host *host; |
| struct nsm_handle *nsm = NULL; |
| struct lockd_net *ln = net_generic(net, lockd_net_id); |
| |
| 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, 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); |
| ln->nrhosts++; |
| 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); |
| |
| WARN_ON_ONCE(host->h_server); |
| |
| if (refcount_dec_and_mutex_lock(&host->h_count, &nlm_host_mutex)) { |
| WARN_ON_ONCE(!list_empty(&host->h_lockowners)); |
| WARN_ON_ONCE(!list_empty(&host->h_granted)); |
| WARN_ON_ONCE(!list_empty(&host->h_reclaim)); |
| |
| 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 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 = SVC_NET(rqstp); |
| 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, |
| }; |
| struct lockd_net *ln = net_generic(net, lockd_net_id); |
| |
| 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, ln->next_gc)) |
| nlm_gc_hosts(net); |
| |
| chain = &nlm_server_hosts[nlm_hash_address(ni.sap)]; |
| hlist_for_each_entry(host, 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); |
| ln->nrhosts++; |
| nrhosts++; |
| |
| refcount_inc(&host->h_count); |
| |
| 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); |
| |
| WARN_ON_ONCE(!host->h_server); |
| refcount_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) { |
| nlm_rebind_host(host); |
| } 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), |
| .cred = host->h_cred, |
| }; |
| |
| /* |
| * 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; |
| } |
| |
| /** |
| * nlm_rebind_host - If needed, force a portmap lookup of the peer's lockd port |
| * @host: NLM host handle for peer |
| * |
| * This is not needed when using a connection-oriented protocol, such as TCP. |
| * The existing autobind mechanism is sufficient to force a rebind when |
| * required, e.g. on connection state transitions. |
| */ |
| void |
| nlm_rebind_host(struct nlm_host *host) |
| { |
| if (host->h_proto != IPPROTO_UDP) |
| return; |
| |
| 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) |
| { |
| if (host) { |
| dprintk("lockd: get host %s\n", host->h_name); |
| refcount_inc(&host->h_count); |
| host->h_expires = jiffies + NLM_HOST_EXPIRE; |
| } |
| return host; |
| } |
| |
| static struct nlm_host *next_host_state(struct hlist_head *cache, |
| struct nsm_handle *nsm, |
| const struct nlm_reboot *info) |
| { |
| struct nlm_host *host; |
| struct hlist_head *chain; |
| |
| mutex_lock(&nlm_host_mutex); |
| for_each_host(host, chain, cache) { |
| if (host->h_nsmhandle == nsm |
| && host->h_nsmstate != info->state) { |
| host->h_nsmstate = info->state; |
| host->h_state++; |
| |
| nlm_get_host(host); |
| mutex_unlock(&nlm_host_mutex); |
| return host; |
| } |
| } |
| |
| mutex_unlock(&nlm_host_mutex); |
| return NULL; |
| } |
| |
| /** |
| * nlm_host_rebooted - Release all resources held by rebooted host |
| * @net: network namespace |
| * @info: pointer to decoded results of NLM_SM_NOTIFY call |
| * |
| * We were notified that the specified host has rebooted. Release |
| * all resources held by that peer. |
| */ |
| void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info) |
| { |
| struct nsm_handle *nsm; |
| struct nlm_host *host; |
| |
| 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; |
| } |
| } |