/* * linux/fs/lockd/mon.c * * The kernel statd client. * * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ #include <linux/types.h> #include <linux/utsname.h> #include <linux/kernel.h> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/xprtsock.h> #include <linux/sunrpc/svc.h> #include <linux/lockd/lockd.h> #include <linux/lockd/sm_inter.h> #define NLMDBG_FACILITY NLMDBG_MONITOR #define XDR_ADDRBUF_LEN (20) static struct rpc_clnt * nsm_create(void); static struct rpc_program nsm_program; /* * Local NSM state */ int nsm_local_state; /* * Common procedure for SM_MON/SM_UNMON calls */ static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) { struct rpc_clnt *clnt; int status; struct nsm_args args; struct rpc_message msg = { .rpc_argp = &args, .rpc_resp = res, }; clnt = nsm_create(); if (IS_ERR(clnt)) { status = PTR_ERR(clnt); goto out; } memset(&args, 0, sizeof(args)); args.mon_name = nsm->sm_name; args.addr = nsm_addr_in(nsm)->sin_addr.s_addr; args.prog = NLM_PROGRAM; args.vers = 3; args.proc = NLMPROC_NSM_NOTIFY; memset(res, 0, sizeof(*res)); msg.rpc_proc = &clnt->cl_procinfo[proc]; status = rpc_call_sync(clnt, &msg, 0); if (status < 0) printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n", status); else status = 0; rpc_shutdown_client(clnt); out: return status; } /* * Set up monitoring of a remote host */ int nsm_monitor(struct nlm_host *host) { struct nsm_handle *nsm = host->h_nsmhandle; struct nsm_res res; int status; dprintk("lockd: nsm_monitor(%s)\n", host->h_name); BUG_ON(nsm == NULL); if (nsm->sm_monitored) return 0; status = nsm_mon_unmon(nsm, SM_MON, &res); if (status < 0 || res.status != 0) printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name); else nsm->sm_monitored = 1; return status; } /* * Cease to monitor remote host */ int nsm_unmonitor(struct nlm_host *host) { struct nsm_handle *nsm = host->h_nsmhandle; struct nsm_res res; int status = 0; if (nsm == NULL) return 0; host->h_nsmhandle = NULL; if (atomic_read(&nsm->sm_count) == 1 && nsm->sm_monitored && !nsm->sm_sticky) { dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); status = nsm_mon_unmon(nsm, SM_UNMON, &res); if (status < 0) printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name); else nsm->sm_monitored = 0; } nsm_release(nsm); return status; } /* * Create NSM client for the local host */ static struct rpc_clnt * nsm_create(void) { struct sockaddr_in sin = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_LOOPBACK), .sin_port = 0, }; struct rpc_create_args args = { .protocol = XPRT_TRANSPORT_UDP, .address = (struct sockaddr *)&sin, .addrsize = sizeof(sin), .servername = "localhost", .program = &nsm_program, .version = SM_VERSION, .authflavor = RPC_AUTH_NULL, }; return rpc_create(&args); } /* * XDR functions for NSM. * * See http://www.opengroup.org/ for details on the Network * Status Monitor wire protocol. */ static __be32 *xdr_encode_nsm_string(__be32 *p, char *string) { size_t len = strlen(string); if (len > SM_MAXSTRLEN) len = SM_MAXSTRLEN; return xdr_encode_opaque(p, string, len); } /* * "mon_name" specifies the host to be monitored. * * Linux uses a text version of the IP address of the remote * host as the host identifier (the "mon_name" argument). * * Linux statd always looks up the canonical hostname first for * whatever remote hostname it receives, so this works alright. */ static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp) { char buffer[XDR_ADDRBUF_LEN + 1]; char *name = argp->mon_name; if (!nsm_use_hostnames) { snprintf(buffer, XDR_ADDRBUF_LEN, "%pI4", &argp->addr); name = buffer; } return xdr_encode_nsm_string(p, name); } /* * The "my_id" argument specifies the hostname and RPC procedure * to be called when the status manager receives notification * (via the SM_NOTIFY call) that the state of host "mon_name" * has changed. */ static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp) { p = xdr_encode_nsm_string(p, utsname()->nodename); if (!p) return ERR_PTR(-EIO); *p++ = htonl(argp->prog); *p++ = htonl(argp->vers); *p++ = htonl(argp->proc); return p; } /* * The "mon_id" argument specifies the non-private arguments * of an SM_MON or SM_UNMON call. */ static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp) { p = xdr_encode_mon_name(p, argp); if (!p) return ERR_PTR(-EIO); return xdr_encode_my_id(p, argp); } /* * The "priv" argument may contain private information required * by the SM_MON call. This information will be supplied in the * SM_NOTIFY call. * * Linux provides the raw IP address of the monitored host, * left in network byte order. */ static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp) { *p++ = argp->addr; *p++ = 0; *p++ = 0; *p++ = 0; return p; } static int xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) { p = xdr_encode_mon_id(p, argp); if (IS_ERR(p)) return PTR_ERR(p); p = xdr_encode_priv(p, argp); if (IS_ERR(p)) return PTR_ERR(p); rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); return 0; } static int xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) { p = xdr_encode_mon_id(p, argp); if (IS_ERR(p)) return PTR_ERR(p); rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); return 0; } static int xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) { resp->status = ntohl(*p++); resp->state = ntohl(*p++); dprintk("nsm: xdr_decode_stat_res status %d state %d\n", resp->status, resp->state); return 0; } static int xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) { resp->state = ntohl(*p++); 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 struct rpc_procinfo nsm_procedures[] = { [SM_MON] = { .p_proc = SM_MON, .p_encode = (kxdrproc_t) xdr_encode_mon, .p_decode = (kxdrproc_t) xdr_decode_stat_res, .p_arglen = SM_mon_sz, .p_replen = SM_monres_sz, .p_statidx = SM_MON, .p_name = "MONITOR", }, [SM_UNMON] = { .p_proc = SM_UNMON, .p_encode = (kxdrproc_t) xdr_encode_unmon, .p_decode = (kxdrproc_t) xdr_decode_stat, .p_arglen = SM_mon_id_sz, .p_replen = SM_unmonres_sz, .p_statidx = SM_UNMON, .p_name = "UNMONITOR", }, }; static struct rpc_version nsm_version1 = { .number = 1, .nrprocs = ARRAY_SIZE(nsm_procedures), .procs = nsm_procedures }; static struct rpc_version * nsm_version[] = { [1] = &nsm_version1, }; static struct rpc_stat nsm_stats; static struct rpc_program nsm_program = { .name = "statd", .number = SM_PROGRAM, .nrvers = ARRAY_SIZE(nsm_version), .version = nsm_version, .stats = &nsm_stats };