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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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/mutex.h>
#include <linux/sunrpc/svc_xprt.h>
#include <net/ipv6.h>
#include "lockd.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 { 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_obj(*host); 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); strscpy(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); }}
/* Callback for rpc_cancel_tasks() - matches all tasks for cancellation */static bool nlmclnt_match_all(const struct rpc_task *task, const void *data){ return true;}
/** * nlmclnt_shutdown_rpc_clnt - safely shut down NLM client RPC operations * @host: nlm_host to shut down * * Cancels outstanding RPC tasks and marks the client as shut down. * Synchronizes with nlmclnt_release_host() via nlm_host_mutex to prevent * races between shutdown and host destruction. Safe to call if h_rpcclnt * is NULL or already shut down. */void nlmclnt_shutdown_rpc_clnt(struct nlm_host *host){ struct rpc_clnt *clnt;
mutex_lock(&nlm_host_mutex); clnt = host->h_rpcclnt; if (clnt) { clnt->cl_shutdown = 1; rpc_cancel_tasks(clnt, -EIO, nlmclnt_match_all, NULL); } mutex_unlock(&nlm_host_mutex);}EXPORT_SYMBOL_GPL(nlmclnt_shutdown_rpc_clnt);
/** * 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 = nlm_timeout * HZ; 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 | RPC_CLNT_CREATE_REUSEPORT), .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. */voidnlm_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 lockd_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 lockd_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); }}
voidnlm_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; } nlmsvc_free_host_resources(host); }
/* 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. */voidnlm_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 voidnlm_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; }}