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578 lines
14 KiB
578 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* linux/fs/lockd/mon.c |
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* |
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* The kernel statd client. |
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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/kernel.h> |
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#include <linux/ktime.h> |
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#include <linux/slab.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/xprtsock.h> |
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#include <linux/sunrpc/svc.h> |
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#include <linux/lockd/lockd.h> |
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#include <asm/unaligned.h> |
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#include "netns.h" |
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#define NLMDBG_FACILITY NLMDBG_MONITOR |
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#define NSM_PROGRAM 100024 |
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#define NSM_VERSION 1 |
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enum { |
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NSMPROC_NULL, |
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NSMPROC_STAT, |
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NSMPROC_MON, |
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NSMPROC_UNMON, |
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NSMPROC_UNMON_ALL, |
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NSMPROC_SIMU_CRASH, |
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NSMPROC_NOTIFY, |
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}; |
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struct nsm_args { |
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struct nsm_private *priv; |
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u32 prog; /* RPC callback info */ |
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u32 vers; |
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u32 proc; |
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char *mon_name; |
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const char *nodename; |
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}; |
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struct nsm_res { |
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u32 status; |
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u32 state; |
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}; |
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static const struct rpc_program nsm_program; |
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static DEFINE_SPINLOCK(nsm_lock); |
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|
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/* |
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* Local NSM state |
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*/ |
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u32 __read_mostly nsm_local_state; |
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bool __read_mostly nsm_use_hostnames; |
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static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm) |
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{ |
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return (struct sockaddr *)&nsm->sm_addr; |
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} |
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static struct rpc_clnt *nsm_create(struct net *net, const char *nodename) |
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{ |
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struct sockaddr_in sin = { |
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.sin_family = AF_INET, |
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.sin_addr.s_addr = htonl(INADDR_LOOPBACK), |
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}; |
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struct rpc_create_args args = { |
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.net = net, |
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.protocol = XPRT_TRANSPORT_TCP, |
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.address = (struct sockaddr *)&sin, |
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.addrsize = sizeof(sin), |
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.servername = "rpc.statd", |
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.nodename = nodename, |
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.program = &nsm_program, |
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.version = NSM_VERSION, |
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.authflavor = RPC_AUTH_NULL, |
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.flags = RPC_CLNT_CREATE_NOPING, |
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.cred = current_cred(), |
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}; |
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return rpc_create(&args); |
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} |
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static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res, |
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const struct nlm_host *host) |
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{ |
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int status; |
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struct rpc_clnt *clnt; |
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struct nsm_args args = { |
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.priv = &nsm->sm_priv, |
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.prog = NLM_PROGRAM, |
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.vers = 3, |
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.proc = NLMPROC_NSM_NOTIFY, |
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.mon_name = nsm->sm_mon_name, |
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.nodename = host->nodename, |
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}; |
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struct rpc_message msg = { |
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.rpc_argp = &args, |
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.rpc_resp = res, |
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}; |
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memset(res, 0, sizeof(*res)); |
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clnt = nsm_create(host->net, host->nodename); |
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if (IS_ERR(clnt)) { |
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dprintk("lockd: failed to create NSM upcall transport, " |
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"status=%ld, net=%x\n", PTR_ERR(clnt), |
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host->net->ns.inum); |
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return PTR_ERR(clnt); |
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} |
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msg.rpc_proc = &clnt->cl_procinfo[proc]; |
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status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN); |
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if (status == -ECONNREFUSED) { |
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dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n", |
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status); |
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rpc_force_rebind(clnt); |
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status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN); |
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} |
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if (status < 0) |
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dprintk("lockd: NSM upcall RPC failed, status=%d\n", |
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status); |
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else |
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status = 0; |
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rpc_shutdown_client(clnt); |
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return status; |
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} |
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/** |
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* nsm_monitor - Notify a peer in case we reboot |
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* @host: pointer to nlm_host of peer to notify |
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* |
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* If this peer is not already monitored, this function sends an |
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* upcall to the local rpc.statd to record the name/address of |
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* the peer to notify in case we reboot. |
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* |
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* Returns zero if the peer is monitored by the local rpc.statd; |
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* otherwise a negative errno value is returned. |
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*/ |
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int nsm_monitor(const struct nlm_host *host) |
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{ |
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struct nsm_handle *nsm = host->h_nsmhandle; |
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struct nsm_res res; |
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int status; |
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dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name); |
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if (nsm->sm_monitored) |
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return 0; |
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/* |
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* Choose whether to record the caller_name or IP address of |
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* this peer in the local rpc.statd's database. |
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*/ |
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nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf; |
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status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host); |
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if (unlikely(res.status != 0)) |
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status = -EIO; |
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if (unlikely(status < 0)) { |
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pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name); |
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return status; |
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} |
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nsm->sm_monitored = 1; |
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if (unlikely(nsm_local_state != res.state)) { |
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nsm_local_state = res.state; |
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dprintk("lockd: NSM state changed to %d\n", nsm_local_state); |
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} |
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return 0; |
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} |
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/** |
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* nsm_unmonitor - Unregister peer notification |
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* @host: pointer to nlm_host of peer to stop monitoring |
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* |
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* If this peer is monitored, this function sends an upcall to |
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* tell the local rpc.statd not to send this peer a notification |
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* when we reboot. |
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*/ |
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void nsm_unmonitor(const struct nlm_host *host) |
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{ |
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struct nsm_handle *nsm = host->h_nsmhandle; |
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struct nsm_res res; |
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int status; |
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if (refcount_read(&nsm->sm_count) == 1 |
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&& nsm->sm_monitored && !nsm->sm_sticky) { |
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dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name); |
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status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host); |
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if (res.status != 0) |
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status = -EIO; |
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if (status < 0) |
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printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", |
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nsm->sm_name); |
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else |
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nsm->sm_monitored = 0; |
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} |
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} |
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static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles, |
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const char *hostname, const size_t len) |
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{ |
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struct nsm_handle *nsm; |
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list_for_each_entry(nsm, nsm_handles, sm_link) |
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if (strlen(nsm->sm_name) == len && |
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memcmp(nsm->sm_name, hostname, len) == 0) |
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return nsm; |
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return NULL; |
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} |
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static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles, |
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const struct sockaddr *sap) |
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{ |
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struct nsm_handle *nsm; |
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list_for_each_entry(nsm, nsm_handles, sm_link) |
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if (rpc_cmp_addr(nsm_addr(nsm), sap)) |
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return nsm; |
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return NULL; |
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} |
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static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles, |
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const struct nsm_private *priv) |
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{ |
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struct nsm_handle *nsm; |
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list_for_each_entry(nsm, nsm_handles, sm_link) |
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if (memcmp(nsm->sm_priv.data, priv->data, |
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sizeof(priv->data)) == 0) |
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return nsm; |
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return NULL; |
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} |
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/* |
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* Construct a unique cookie to match this nsm_handle to this monitored |
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* host. It is passed to the local rpc.statd via NSMPROC_MON, and |
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* returned via NLMPROC_SM_NOTIFY, in the "priv" field of these |
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* requests. |
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* |
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* The NSM protocol requires that these cookies be unique while the |
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* system is running. We prefer a stronger requirement of making them |
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* unique across reboots. If user space bugs cause a stale cookie to |
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* be sent to the kernel, it could cause the wrong host to lose its |
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* lock state if cookies were not unique across reboots. |
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* |
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* The cookies are exposed only to local user space via loopback. They |
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* do not appear on the physical network. If we want greater security |
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* for some reason, nsm_init_private() could perform a one-way hash to |
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* obscure the contents of the cookie. |
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*/ |
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static void nsm_init_private(struct nsm_handle *nsm) |
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{ |
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u64 *p = (u64 *)&nsm->sm_priv.data; |
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s64 ns; |
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ns = ktime_get_ns(); |
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put_unaligned(ns, p); |
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put_unaligned((unsigned long)nsm, p + 1); |
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} |
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static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap, |
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const size_t salen, |
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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 nsm_handle *new; |
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new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL); |
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if (unlikely(new == NULL)) |
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return NULL; |
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refcount_set(&new->sm_count, 1); |
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new->sm_name = (char *)(new + 1); |
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memcpy(nsm_addr(new), sap, salen); |
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new->sm_addrlen = salen; |
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nsm_init_private(new); |
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if (rpc_ntop(nsm_addr(new), new->sm_addrbuf, |
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sizeof(new->sm_addrbuf)) == 0) |
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(void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf), |
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"unsupported address family"); |
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memcpy(new->sm_name, hostname, hostname_len); |
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new->sm_name[hostname_len] = '\0'; |
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return new; |
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} |
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/** |
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* nsm_get_handle - Find or create a cached nsm_handle |
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* @net: network namespace |
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* @sap: pointer to socket address of handle to find |
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* @salen: length of socket address |
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* @hostname: pointer to C string containing hostname to find |
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* @hostname_len: length of C string |
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* |
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* Behavior is modulated by the global nsm_use_hostnames variable. |
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* |
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* Returns a cached nsm_handle after bumping its ref count, or |
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* returns a fresh nsm_handle if a handle that matches @sap and/or |
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* @hostname cannot be found in the handle cache. Returns NULL if |
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* an error occurs. |
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*/ |
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struct nsm_handle *nsm_get_handle(const struct net *net, |
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const struct sockaddr *sap, |
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const size_t salen, const char *hostname, |
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const size_t hostname_len) |
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{ |
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struct nsm_handle *cached, *new = NULL; |
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struct lockd_net *ln = net_generic(net, lockd_net_id); |
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if (hostname && memchr(hostname, '/', hostname_len) != NULL) { |
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if (printk_ratelimit()) { |
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printk(KERN_WARNING "Invalid hostname \"%.*s\" " |
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"in NFS lock request\n", |
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(int)hostname_len, hostname); |
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} |
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return NULL; |
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} |
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retry: |
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spin_lock(&nsm_lock); |
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if (nsm_use_hostnames && hostname != NULL) |
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cached = nsm_lookup_hostname(&ln->nsm_handles, |
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hostname, hostname_len); |
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else |
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cached = nsm_lookup_addr(&ln->nsm_handles, sap); |
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if (cached != NULL) { |
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refcount_inc(&cached->sm_count); |
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spin_unlock(&nsm_lock); |
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kfree(new); |
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dprintk("lockd: found nsm_handle for %s (%s), " |
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"cnt %d\n", cached->sm_name, |
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cached->sm_addrbuf, |
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refcount_read(&cached->sm_count)); |
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return cached; |
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} |
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if (new != NULL) { |
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list_add(&new->sm_link, &ln->nsm_handles); |
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spin_unlock(&nsm_lock); |
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dprintk("lockd: created nsm_handle for %s (%s)\n", |
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new->sm_name, new->sm_addrbuf); |
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return new; |
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} |
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spin_unlock(&nsm_lock); |
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new = nsm_create_handle(sap, salen, hostname, hostname_len); |
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if (unlikely(new == NULL)) |
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return NULL; |
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goto retry; |
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} |
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/** |
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* nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle |
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* @net: network namespace |
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* @info: pointer to NLMPROC_SM_NOTIFY arguments |
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* |
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* Returns a matching nsm_handle if found in the nsm cache. The returned |
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* nsm_handle's reference count is bumped. Otherwise returns NULL if some |
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* error occurred. |
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*/ |
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struct nsm_handle *nsm_reboot_lookup(const struct net *net, |
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const struct nlm_reboot *info) |
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{ |
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struct nsm_handle *cached; |
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struct lockd_net *ln = net_generic(net, lockd_net_id); |
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spin_lock(&nsm_lock); |
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cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv); |
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if (unlikely(cached == NULL)) { |
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spin_unlock(&nsm_lock); |
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dprintk("lockd: never saw rebooted peer '%.*s' before\n", |
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info->len, info->mon); |
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return cached; |
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} |
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refcount_inc(&cached->sm_count); |
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spin_unlock(&nsm_lock); |
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dprintk("lockd: host %s (%s) rebooted, cnt %d\n", |
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cached->sm_name, cached->sm_addrbuf, |
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refcount_read(&cached->sm_count)); |
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return cached; |
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} |
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/** |
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* nsm_release - Release an NSM handle |
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* @nsm: pointer to handle to be released |
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* |
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*/ |
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void nsm_release(struct nsm_handle *nsm) |
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{ |
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if (refcount_dec_and_lock(&nsm->sm_count, &nsm_lock)) { |
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list_del(&nsm->sm_link); |
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spin_unlock(&nsm_lock); |
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dprintk("lockd: destroyed nsm_handle for %s (%s)\n", |
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nsm->sm_name, nsm->sm_addrbuf); |
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kfree(nsm); |
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} |
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} |
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/* |
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* XDR functions for NSM. |
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* |
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* See https://www.opengroup.org/ for details on the Network |
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* Status Monitor wire protocol. |
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*/ |
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static void encode_nsm_string(struct xdr_stream *xdr, const char *string) |
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{ |
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const u32 len = strlen(string); |
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__be32 *p; |
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p = xdr_reserve_space(xdr, 4 + len); |
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xdr_encode_opaque(p, string, len); |
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} |
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/* |
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* "mon_name" specifies the host to be monitored. |
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*/ |
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static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp) |
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{ |
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encode_nsm_string(xdr, argp->mon_name); |
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} |
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/* |
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* The "my_id" argument specifies the hostname and RPC procedure |
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* to be called when the status manager receives notification |
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* (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name" |
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* has changed. |
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*/ |
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static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp) |
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{ |
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__be32 *p; |
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encode_nsm_string(xdr, argp->nodename); |
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p = xdr_reserve_space(xdr, 4 + 4 + 4); |
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*p++ = cpu_to_be32(argp->prog); |
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*p++ = cpu_to_be32(argp->vers); |
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*p = cpu_to_be32(argp->proc); |
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} |
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/* |
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* The "mon_id" argument specifies the non-private arguments |
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* of an NSMPROC_MON or NSMPROC_UNMON call. |
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*/ |
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static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp) |
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{ |
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encode_mon_name(xdr, argp); |
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encode_my_id(xdr, argp); |
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} |
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/* |
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* The "priv" argument may contain private information required |
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* by the NSMPROC_MON call. This information will be supplied in the |
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* NLMPROC_SM_NOTIFY call. |
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*/ |
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static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp) |
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{ |
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__be32 *p; |
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p = xdr_reserve_space(xdr, SM_PRIV_SIZE); |
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xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE); |
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} |
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static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr, |
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const void *argp) |
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{ |
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encode_mon_id(xdr, argp); |
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encode_priv(xdr, argp); |
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} |
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static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr, |
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const void *argp) |
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{ |
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encode_mon_id(xdr, argp); |
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} |
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static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp, |
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struct xdr_stream *xdr, |
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void *data) |
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{ |
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struct nsm_res *resp = data; |
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__be32 *p; |
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p = xdr_inline_decode(xdr, 4 + 4); |
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if (unlikely(p == NULL)) |
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return -EIO; |
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resp->status = be32_to_cpup(p++); |
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resp->state = be32_to_cpup(p); |
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dprintk("lockd: %s status %d state %d\n", |
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__func__, resp->status, resp->state); |
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return 0; |
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} |
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static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp, |
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struct xdr_stream *xdr, |
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void *data) |
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{ |
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struct nsm_res *resp = data; |
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__be32 *p; |
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p = xdr_inline_decode(xdr, 4); |
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if (unlikely(p == NULL)) |
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return -EIO; |
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resp->state = be32_to_cpup(p); |
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dprintk("lockd: %s state %d\n", __func__, resp->state); |
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return 0; |
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} |
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#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) |
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#define SM_my_id_sz (SM_my_name_sz+3) |
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#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) |
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#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz) |
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#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE)) |
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#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz) |
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#define SM_monres_sz 2 |
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#define SM_unmonres_sz 1 |
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static const struct rpc_procinfo nsm_procedures[] = { |
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[NSMPROC_MON] = { |
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.p_proc = NSMPROC_MON, |
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.p_encode = nsm_xdr_enc_mon, |
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.p_decode = nsm_xdr_dec_stat_res, |
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.p_arglen = SM_mon_sz, |
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.p_replen = SM_monres_sz, |
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.p_statidx = NSMPROC_MON, |
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.p_name = "MONITOR", |
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}, |
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[NSMPROC_UNMON] = { |
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.p_proc = NSMPROC_UNMON, |
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.p_encode = nsm_xdr_enc_unmon, |
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.p_decode = nsm_xdr_dec_stat, |
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.p_arglen = SM_mon_id_sz, |
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.p_replen = SM_unmonres_sz, |
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.p_statidx = NSMPROC_UNMON, |
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.p_name = "UNMONITOR", |
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}, |
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}; |
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static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)]; |
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static const struct rpc_version nsm_version1 = { |
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.number = 1, |
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.nrprocs = ARRAY_SIZE(nsm_procedures), |
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.procs = nsm_procedures, |
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.counts = nsm_version1_counts, |
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}; |
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|
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static const struct rpc_version *nsm_version[] = { |
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[1] = &nsm_version1, |
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}; |
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|
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static struct rpc_stat nsm_stats; |
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|
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static const struct rpc_program nsm_program = { |
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.name = "statd", |
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.number = NSM_PROGRAM, |
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.nrvers = ARRAY_SIZE(nsm_version), |
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.version = nsm_version, |
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.stats = &nsm_stats |
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};
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