1 /* 2 * linux/fs/lockd/mon.c 3 * 4 * The kernel statd client. 5 * 6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> 7 */ 8 9 #include <linux/types.h> 10 #include <linux/utsname.h> 11 #include <linux/kernel.h> 12 #include <linux/sunrpc/clnt.h> 13 #include <linux/sunrpc/svc.h> 14 #include <linux/lockd/lockd.h> 15 #include <linux/lockd/sm_inter.h> 16 17 18 #define NLMDBG_FACILITY NLMDBG_MONITOR 19 20 static struct rpc_clnt * nsm_create(void); 21 22 static struct rpc_program nsm_program; 23 24 /* 25 * Local NSM state 26 */ 27 u32 nsm_local_state; 28 29 /* 30 * Common procedure for SM_MON/SM_UNMON calls 31 */ 32 static int 33 nsm_mon_unmon(struct nlm_host *host, u32 proc, struct nsm_res *res) 34 { 35 struct rpc_clnt *clnt; 36 int status; 37 struct nsm_args args; 38 struct rpc_message msg = { 39 .rpc_argp = &args, 40 .rpc_resp = res, 41 }; 42 43 clnt = nsm_create(); 44 if (IS_ERR(clnt)) { 45 status = PTR_ERR(clnt); 46 goto out; 47 } 48 49 args.addr = host->h_addr.sin_addr.s_addr; 50 args.proto= (host->h_proto<<1) | host->h_server; 51 args.prog = NLM_PROGRAM; 52 args.vers = host->h_version; 53 args.proc = NLMPROC_NSM_NOTIFY; 54 memset(res, 0, sizeof(*res)); 55 56 msg.rpc_proc = &clnt->cl_procinfo[proc]; 57 status = rpc_call_sync(clnt, &msg, 0); 58 if (status < 0) 59 printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n", 60 status); 61 else 62 status = 0; 63 out: 64 return status; 65 } 66 67 /* 68 * Set up monitoring of a remote host 69 */ 70 int 71 nsm_monitor(struct nlm_host *host) 72 { 73 struct nsm_res res; 74 int status; 75 76 dprintk("lockd: nsm_monitor(%s)\n", host->h_name); 77 78 status = nsm_mon_unmon(host, SM_MON, &res); 79 80 if (status < 0 || res.status != 0) 81 printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name); 82 else 83 host->h_monitored = 1; 84 return status; 85 } 86 87 /* 88 * Cease to monitor remote host 89 */ 90 int 91 nsm_unmonitor(struct nlm_host *host) 92 { 93 struct nsm_res res; 94 int status; 95 96 dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); 97 98 status = nsm_mon_unmon(host, SM_UNMON, &res); 99 if (status < 0) 100 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name); 101 else 102 host->h_monitored = 0; 103 return status; 104 } 105 106 /* 107 * Create NSM client for the local host 108 */ 109 static struct rpc_clnt * 110 nsm_create(void) 111 { 112 struct rpc_xprt *xprt; 113 struct rpc_clnt *clnt; 114 struct sockaddr_in sin; 115 116 sin.sin_family = AF_INET; 117 sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 118 sin.sin_port = 0; 119 120 xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL); 121 if (IS_ERR(xprt)) 122 return (struct rpc_clnt *)xprt; 123 xprt->resvport = 1; /* NSM requires a reserved port */ 124 125 clnt = rpc_create_client(xprt, "localhost", 126 &nsm_program, SM_VERSION, 127 RPC_AUTH_NULL); 128 if (IS_ERR(clnt)) 129 goto out_err; 130 clnt->cl_softrtry = 1; 131 clnt->cl_oneshot = 1; 132 return clnt; 133 134 out_err: 135 return clnt; 136 } 137 138 /* 139 * XDR functions for NSM. 140 */ 141 142 static u32 * 143 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp) 144 { 145 char buffer[20]; 146 147 /* 148 * Use the dotted-quad IP address of the remote host as 149 * identifier. Linux statd always looks up the canonical 150 * hostname first for whatever remote hostname it receives, 151 * so this works alright. 152 */ 153 sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr)); 154 if (!(p = xdr_encode_string(p, buffer)) 155 || !(p = xdr_encode_string(p, system_utsname.nodename))) 156 return ERR_PTR(-EIO); 157 *p++ = htonl(argp->prog); 158 *p++ = htonl(argp->vers); 159 *p++ = htonl(argp->proc); 160 161 return p; 162 } 163 164 static int 165 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp) 166 { 167 p = xdr_encode_common(rqstp, p, argp); 168 if (IS_ERR(p)) 169 return PTR_ERR(p); 170 *p++ = argp->addr; 171 *p++ = argp->vers; 172 *p++ = argp->proto; 173 *p++ = 0; 174 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 175 return 0; 176 } 177 178 static int 179 xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp) 180 { 181 p = xdr_encode_common(rqstp, p, argp); 182 if (IS_ERR(p)) 183 return PTR_ERR(p); 184 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 185 return 0; 186 } 187 188 static int 189 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp) 190 { 191 resp->status = ntohl(*p++); 192 resp->state = ntohl(*p++); 193 dprintk("nsm: xdr_decode_stat_res status %d state %d\n", 194 resp->status, resp->state); 195 return 0; 196 } 197 198 static int 199 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp) 200 { 201 resp->state = ntohl(*p++); 202 return 0; 203 } 204 205 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 206 #define SM_my_id_sz (3+1+SM_my_name_sz) 207 #define SM_mon_id_sz (1+XDR_QUADLEN(20)+SM_my_id_sz) 208 #define SM_mon_sz (SM_mon_id_sz+4) 209 #define SM_monres_sz 2 210 #define SM_unmonres_sz 1 211 212 #ifndef MAX 213 # define MAX(a, b) (((a) > (b))? (a) : (b)) 214 #endif 215 216 static struct rpc_procinfo nsm_procedures[] = { 217 [SM_MON] = { 218 .p_proc = SM_MON, 219 .p_encode = (kxdrproc_t) xdr_encode_mon, 220 .p_decode = (kxdrproc_t) xdr_decode_stat_res, 221 .p_bufsiz = MAX(SM_mon_sz, SM_monres_sz) << 2, 222 .p_statidx = SM_MON, 223 .p_name = "MONITOR", 224 }, 225 [SM_UNMON] = { 226 .p_proc = SM_UNMON, 227 .p_encode = (kxdrproc_t) xdr_encode_unmon, 228 .p_decode = (kxdrproc_t) xdr_decode_stat, 229 .p_bufsiz = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2, 230 .p_statidx = SM_UNMON, 231 .p_name = "UNMONITOR", 232 }, 233 }; 234 235 static struct rpc_version nsm_version1 = { 236 .number = 1, 237 .nrprocs = ARRAY_SIZE(nsm_procedures), 238 .procs = nsm_procedures 239 }; 240 241 static struct rpc_version * nsm_version[] = { 242 [1] = &nsm_version1, 243 }; 244 245 static struct rpc_stat nsm_stats; 246 247 static struct rpc_program nsm_program = { 248 .name = "statd", 249 .number = SM_PROGRAM, 250 .nrvers = ARRAY_SIZE(nsm_version), 251 .version = nsm_version, 252 .stats = &nsm_stats 253 }; 254