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-rw-r--r--fs/lockd/mon.c581
1 files changed, 581 insertions, 0 deletions
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
new file mode 100644
index 000000000..87a0f207d
--- /dev/null
+++ b/fs/lockd/mon.c
@@ -0,0 +1,581 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/mon.c
+ *
+ * The kernel statd client.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/xprtsock.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+
+#include <asm/unaligned.h>
+
+#include "netns.h"
+
+#define NLMDBG_FACILITY NLMDBG_MONITOR
+#define NSM_PROGRAM 100024
+#define NSM_VERSION 1
+
+enum {
+ NSMPROC_NULL,
+ NSMPROC_STAT,
+ NSMPROC_MON,
+ NSMPROC_UNMON,
+ NSMPROC_UNMON_ALL,
+ NSMPROC_SIMU_CRASH,
+ NSMPROC_NOTIFY,
+};
+
+struct nsm_args {
+ struct nsm_private *priv;
+ u32 prog; /* RPC callback info */
+ u32 vers;
+ u32 proc;
+
+ char *mon_name;
+ const char *nodename;
+};
+
+struct nsm_res {
+ u32 status;
+ u32 state;
+};
+
+static const struct rpc_program nsm_program;
+static DEFINE_SPINLOCK(nsm_lock);
+
+/*
+ * Local NSM state
+ */
+u32 __read_mostly nsm_local_state;
+bool __read_mostly nsm_use_hostnames;
+
+static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
+{
+ return (struct sockaddr *)&nsm->sm_addr;
+}
+
+static struct rpc_clnt *nsm_create(struct net *net, const char *nodename)
+{
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
+ };
+ struct rpc_create_args args = {
+ .net = net,
+ .protocol = XPRT_TRANSPORT_TCP,
+ .address = (struct sockaddr *)&sin,
+ .addrsize = sizeof(sin),
+ .servername = "rpc.statd",
+ .nodename = nodename,
+ .program = &nsm_program,
+ .version = NSM_VERSION,
+ .authflavor = RPC_AUTH_NULL,
+ .flags = RPC_CLNT_CREATE_NOPING,
+ .cred = current_cred(),
+ };
+
+ return rpc_create(&args);
+}
+
+static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
+ const struct nlm_host *host)
+{
+ int status;
+ struct rpc_clnt *clnt;
+ struct nsm_args args = {
+ .priv = &nsm->sm_priv,
+ .prog = NLM_PROGRAM,
+ .vers = 3,
+ .proc = NLMPROC_NSM_NOTIFY,
+ .mon_name = nsm->sm_mon_name,
+ .nodename = host->nodename,
+ };
+ struct rpc_message msg = {
+ .rpc_argp = &args,
+ .rpc_resp = res,
+ };
+
+ memset(res, 0, sizeof(*res));
+
+ clnt = nsm_create(host->net, host->nodename);
+ if (IS_ERR(clnt)) {
+ dprintk("lockd: failed to create NSM upcall transport, "
+ "status=%ld, net=%x\n", PTR_ERR(clnt),
+ host->net->ns.inum);
+ return PTR_ERR(clnt);
+ }
+
+ msg.rpc_proc = &clnt->cl_procinfo[proc];
+ status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
+ if (status == -ECONNREFUSED) {
+ dprintk("lockd: NSM upcall RPC failed, status=%d, forcing rebind\n",
+ status);
+ rpc_force_rebind(clnt);
+ status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);
+ }
+ if (status < 0)
+ dprintk("lockd: NSM upcall RPC failed, status=%d\n",
+ status);
+ else
+ status = 0;
+
+ rpc_shutdown_client(clnt);
+ return status;
+}
+
+/**
+ * nsm_monitor - Notify a peer in case we reboot
+ * @host: pointer to nlm_host of peer to notify
+ *
+ * If this peer is not already monitored, this function sends an
+ * upcall to the local rpc.statd to record the name/address of
+ * the peer to notify in case we reboot.
+ *
+ * Returns zero if the peer is monitored by the local rpc.statd;
+ * otherwise a negative errno value is returned.
+ */
+int nsm_monitor(const struct nlm_host *host)
+{
+ struct nsm_handle *nsm = host->h_nsmhandle;
+ struct nsm_res res;
+ int status;
+
+ dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
+
+ if (nsm->sm_monitored)
+ return 0;
+
+ /*
+ * Choose whether to record the caller_name or IP address of
+ * this peer in the local rpc.statd's database.
+ */
+ nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;
+
+ status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);
+ if (unlikely(res.status != 0))
+ status = -EIO;
+ if (unlikely(status < 0)) {
+ pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
+ return status;
+ }
+
+ nsm->sm_monitored = 1;
+ if (unlikely(nsm_local_state != res.state)) {
+ nsm_local_state = res.state;
+ dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
+ }
+ return 0;
+}
+
+/**
+ * nsm_unmonitor - Unregister peer notification
+ * @host: pointer to nlm_host of peer to stop monitoring
+ *
+ * If this peer is monitored, this function sends an upcall to
+ * tell the local rpc.statd not to send this peer a notification
+ * when we reboot.
+ */
+void nsm_unmonitor(const struct nlm_host *host)
+{
+ struct nsm_handle *nsm = host->h_nsmhandle;
+ struct nsm_res res;
+ int status;
+
+ if (refcount_read(&nsm->sm_count) == 1
+ && nsm->sm_monitored && !nsm->sm_sticky) {
+ dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
+
+ status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);
+ if (res.status != 0)
+ status = -EIO;
+ if (status < 0)
+ printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
+ nsm->sm_name);
+ else
+ nsm->sm_monitored = 0;
+ }
+}
+
+static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles,
+ const char *hostname, const size_t len)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, nsm_handles, sm_link)
+ if (strlen(nsm->sm_name) == len &&
+ memcmp(nsm->sm_name, hostname, len) == 0)
+ return nsm;
+ return NULL;
+}
+
+static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles,
+ const struct sockaddr *sap)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, nsm_handles, sm_link)
+ if (rpc_cmp_addr(nsm_addr(nsm), sap))
+ return nsm;
+ return NULL;
+}
+
+static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles,
+ const struct nsm_private *priv)
+{
+ struct nsm_handle *nsm;
+
+ list_for_each_entry(nsm, nsm_handles, sm_link)
+ if (memcmp(nsm->sm_priv.data, priv->data,
+ sizeof(priv->data)) == 0)
+ return nsm;
+ return NULL;
+}
+
+/*
+ * Construct a unique cookie to match this nsm_handle to this monitored
+ * host. It is passed to the local rpc.statd via NSMPROC_MON, and
+ * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
+ * requests.
+ *
+ * The NSM protocol requires that these cookies be unique while the
+ * system is running. We prefer a stronger requirement of making them
+ * unique across reboots. If user space bugs cause a stale cookie to
+ * be sent to the kernel, it could cause the wrong host to lose its
+ * lock state if cookies were not unique across reboots.
+ *
+ * The cookies are exposed only to local user space via loopback. They
+ * do not appear on the physical network. If we want greater security
+ * for some reason, nsm_init_private() could perform a one-way hash to
+ * obscure the contents of the cookie.
+ */
+static void nsm_init_private(struct nsm_handle *nsm)
+{
+ u64 *p = (u64 *)&nsm->sm_priv.data;
+ s64 ns;
+
+ ns = ktime_get_ns();
+ put_unaligned(ns, p);
+ put_unaligned((unsigned long)nsm, p + 1);
+}
+
+static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
+ const size_t salen,
+ const char *hostname,
+ const size_t hostname_len)
+{
+ struct nsm_handle *new;
+
+ if (!hostname)
+ return NULL;
+
+ new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
+ if (unlikely(new == NULL))
+ return NULL;
+
+ refcount_set(&new->sm_count, 1);
+ new->sm_name = (char *)(new + 1);
+ memcpy(nsm_addr(new), sap, salen);
+ new->sm_addrlen = salen;
+ nsm_init_private(new);
+
+ if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
+ sizeof(new->sm_addrbuf)) == 0)
+ (void)snprintf(new->sm_addrbuf, sizeof(new->sm_addrbuf),
+ "unsupported address family");
+ memcpy(new->sm_name, hostname, hostname_len);
+ new->sm_name[hostname_len] = '\0';
+
+ return new;
+}
+
+/**
+ * nsm_get_handle - Find or create a cached nsm_handle
+ * @net: network namespace
+ * @sap: pointer to socket address of handle to find
+ * @salen: length of socket address
+ * @hostname: pointer to C string containing hostname to find
+ * @hostname_len: length of C string
+ *
+ * Behavior is modulated by the global nsm_use_hostnames variable.
+ *
+ * Returns a cached nsm_handle after bumping its ref count, or
+ * returns a fresh nsm_handle if a handle that matches @sap and/or
+ * @hostname cannot be found in the handle cache. Returns NULL if
+ * an error occurs.
+ */
+struct nsm_handle *nsm_get_handle(const struct net *net,
+ const struct sockaddr *sap,
+ const size_t salen, const char *hostname,
+ const size_t hostname_len)
+{
+ struct nsm_handle *cached, *new = NULL;
+ struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+ if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
+ if (printk_ratelimit()) {
+ printk(KERN_WARNING "Invalid hostname \"%.*s\" "
+ "in NFS lock request\n",
+ (int)hostname_len, hostname);
+ }
+ return NULL;
+ }
+
+retry:
+ spin_lock(&nsm_lock);
+
+ if (nsm_use_hostnames && hostname != NULL)
+ cached = nsm_lookup_hostname(&ln->nsm_handles,
+ hostname, hostname_len);
+ else
+ cached = nsm_lookup_addr(&ln->nsm_handles, sap);
+
+ if (cached != NULL) {
+ refcount_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+ kfree(new);
+ dprintk("lockd: found nsm_handle for %s (%s), "
+ "cnt %d\n", cached->sm_name,
+ cached->sm_addrbuf,
+ refcount_read(&cached->sm_count));
+ return cached;
+ }
+
+ if (new != NULL) {
+ list_add(&new->sm_link, &ln->nsm_handles);
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: created nsm_handle for %s (%s)\n",
+ new->sm_name, new->sm_addrbuf);
+ return new;
+ }
+
+ spin_unlock(&nsm_lock);
+
+ new = nsm_create_handle(sap, salen, hostname, hostname_len);
+ if (unlikely(new == NULL))
+ return NULL;
+ goto retry;
+}
+
+/**
+ * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
+ * @net: network namespace
+ * @info: pointer to NLMPROC_SM_NOTIFY arguments
+ *
+ * Returns a matching nsm_handle if found in the nsm cache. The returned
+ * nsm_handle's reference count is bumped. Otherwise returns NULL if some
+ * error occurred.
+ */
+struct nsm_handle *nsm_reboot_lookup(const struct net *net,
+ const struct nlm_reboot *info)
+{
+ struct nsm_handle *cached;
+ struct lockd_net *ln = net_generic(net, lockd_net_id);
+
+ spin_lock(&nsm_lock);
+
+ cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv);
+ if (unlikely(cached == NULL)) {
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: never saw rebooted peer '%.*s' before\n",
+ info->len, info->mon);
+ return cached;
+ }
+
+ refcount_inc(&cached->sm_count);
+ spin_unlock(&nsm_lock);
+
+ dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
+ cached->sm_name, cached->sm_addrbuf,
+ refcount_read(&cached->sm_count));
+ return cached;
+}
+
+/**
+ * nsm_release - Release an NSM handle
+ * @nsm: pointer to handle to be released
+ *
+ */
+void nsm_release(struct nsm_handle *nsm)
+{
+ if (refcount_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
+ list_del(&nsm->sm_link);
+ spin_unlock(&nsm_lock);
+ dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
+ nsm->sm_name, nsm->sm_addrbuf);
+ kfree(nsm);
+ }
+}
+
+/*
+ * XDR functions for NSM.
+ *
+ * See https://www.opengroup.org/ for details on the Network
+ * Status Monitor wire protocol.
+ */
+
+static void encode_nsm_string(struct xdr_stream *xdr, const char *string)
+{
+ const u32 len = strlen(string);
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4 + len);
+ xdr_encode_opaque(p, string, len);
+}
+
+/*
+ * "mon_name" specifies the host to be monitored.
+ */
+static void encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+ encode_nsm_string(xdr, argp->mon_name);
+}
+
+/*
+ * The "my_id" argument specifies the hostname and RPC procedure
+ * to be called when the status manager receives notification
+ * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
+ * has changed.
+ */
+static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+ __be32 *p;
+
+ encode_nsm_string(xdr, argp->nodename);
+ p = xdr_reserve_space(xdr, 4 + 4 + 4);
+ *p++ = cpu_to_be32(argp->prog);
+ *p++ = cpu_to_be32(argp->vers);
+ *p = cpu_to_be32(argp->proc);
+}
+
+/*
+ * The "mon_id" argument specifies the non-private arguments
+ * of an NSMPROC_MON or NSMPROC_UNMON call.
+ */
+static void encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+ encode_mon_name(xdr, argp);
+ encode_my_id(xdr, argp);
+}
+
+/*
+ * The "priv" argument may contain private information required
+ * by the NSMPROC_MON call. This information will be supplied in the
+ * NLMPROC_SM_NOTIFY call.
+ */
+static void encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
+ xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
+}
+
+static void nsm_xdr_enc_mon(struct rpc_rqst *req, struct xdr_stream *xdr,
+ const void *argp)
+{
+ encode_mon_id(xdr, argp);
+ encode_priv(xdr, argp);
+}
+
+static void nsm_xdr_enc_unmon(struct rpc_rqst *req, struct xdr_stream *xdr,
+ const void *argp)
+{
+ encode_mon_id(xdr, argp);
+}
+
+static int nsm_xdr_dec_stat_res(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct nsm_res *resp = data;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4 + 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+ resp->status = be32_to_cpup(p++);
+ resp->state = be32_to_cpup(p);
+
+ dprintk("lockd: %s status %d state %d\n",
+ __func__, resp->status, resp->state);
+ return 0;
+}
+
+static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ void *data)
+{
+ struct nsm_res *resp = data;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -EIO;
+ resp->state = be32_to_cpup(p);
+
+ dprintk("lockd: %s state %d\n", __func__, resp->state);
+ return 0;
+}
+
+#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
+#define SM_my_id_sz (SM_my_name_sz+3)
+#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
+#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
+#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
+#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
+#define SM_monres_sz 2
+#define SM_unmonres_sz 1
+
+static const struct rpc_procinfo nsm_procedures[] = {
+[NSMPROC_MON] = {
+ .p_proc = NSMPROC_MON,
+ .p_encode = nsm_xdr_enc_mon,
+ .p_decode = nsm_xdr_dec_stat_res,
+ .p_arglen = SM_mon_sz,
+ .p_replen = SM_monres_sz,
+ .p_statidx = NSMPROC_MON,
+ .p_name = "MONITOR",
+ },
+[NSMPROC_UNMON] = {
+ .p_proc = NSMPROC_UNMON,
+ .p_encode = nsm_xdr_enc_unmon,
+ .p_decode = nsm_xdr_dec_stat,
+ .p_arglen = SM_mon_id_sz,
+ .p_replen = SM_unmonres_sz,
+ .p_statidx = NSMPROC_UNMON,
+ .p_name = "UNMONITOR",
+ },
+};
+
+static unsigned int nsm_version1_counts[ARRAY_SIZE(nsm_procedures)];
+static const struct rpc_version nsm_version1 = {
+ .number = 1,
+ .nrprocs = ARRAY_SIZE(nsm_procedures),
+ .procs = nsm_procedures,
+ .counts = nsm_version1_counts,
+};
+
+static const struct rpc_version *nsm_version[] = {
+ [1] = &nsm_version1,
+};
+
+static struct rpc_stat nsm_stats;
+
+static const struct rpc_program nsm_program = {
+ .name = "statd",
+ .number = NSM_PROGRAM,
+ .nrvers = ARRAY_SIZE(nsm_version),
+ .version = nsm_version,
+ .stats = &nsm_stats
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-14 18:54:08 +0000