| // 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, |
| }; |
| |
| 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; |
| |
| 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 http://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 |
| }; |