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/xprtsock.h> 14 #include <linux/sunrpc/svc.h> 15 #include <linux/lockd/lockd.h> 16 #include <linux/lockd/sm_inter.h> 17 18 19 #define NLMDBG_FACILITY NLMDBG_MONITOR 20 21 static struct rpc_clnt * nsm_create(void); 22 23 static struct rpc_program nsm_program; 24 25 /* 26 * Local NSM state 27 */ 28 int nsm_local_state; 29 30 /* 31 * Common procedure for SM_MON/SM_UNMON calls 32 */ 33 static int 34 nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) 35 { 36 struct rpc_clnt *clnt; 37 int status; 38 struct nsm_args args = { 39 .addr = nsm_addr_in(nsm)->sin_addr.s_addr, 40 .prog = NLM_PROGRAM, 41 .vers = 3, 42 .proc = NLMPROC_NSM_NOTIFY, 43 .mon_name = nsm->sm_mon_name, 44 }; 45 struct rpc_message msg = { 46 .rpc_argp = &args, 47 .rpc_resp = res, 48 }; 49 50 clnt = nsm_create(); 51 if (IS_ERR(clnt)) { 52 status = PTR_ERR(clnt); 53 dprintk("lockd: failed to create NSM upcall transport, " 54 "status=%d\n", status); 55 goto out; 56 } 57 58 memset(res, 0, sizeof(*res)); 59 60 msg.rpc_proc = &clnt->cl_procinfo[proc]; 61 status = rpc_call_sync(clnt, &msg, 0); 62 if (status < 0) 63 dprintk("lockd: NSM upcall RPC failed, status=%d\n", 64 status); 65 else 66 status = 0; 67 rpc_shutdown_client(clnt); 68 out: 69 return status; 70 } 71 72 /** 73 * nsm_monitor - Notify a peer in case we reboot 74 * @host: pointer to nlm_host of peer to notify 75 * 76 * If this peer is not already monitored, this function sends an 77 * upcall to the local rpc.statd to record the name/address of 78 * the peer to notify in case we reboot. 79 * 80 * Returns zero if the peer is monitored by the local rpc.statd; 81 * otherwise a negative errno value is returned. 82 */ 83 int nsm_monitor(const struct nlm_host *host) 84 { 85 struct nsm_handle *nsm = host->h_nsmhandle; 86 struct nsm_res res; 87 int status; 88 89 dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name); 90 91 if (nsm->sm_monitored) 92 return 0; 93 94 /* 95 * Choose whether to record the caller_name or IP address of 96 * this peer in the local rpc.statd's database. 97 */ 98 nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf; 99 100 status = nsm_mon_unmon(nsm, SM_MON, &res); 101 if (res.status != 0) 102 status = -EIO; 103 if (status < 0) 104 printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name); 105 else 106 nsm->sm_monitored = 1; 107 return status; 108 } 109 110 /** 111 * nsm_unmonitor - Unregister peer notification 112 * @host: pointer to nlm_host of peer to stop monitoring 113 * 114 * If this peer is monitored, this function sends an upcall to 115 * tell the local rpc.statd not to send this peer a notification 116 * when we reboot. 117 */ 118 void nsm_unmonitor(const struct nlm_host *host) 119 { 120 struct nsm_handle *nsm = host->h_nsmhandle; 121 struct nsm_res res; 122 int status; 123 124 if (atomic_read(&nsm->sm_count) == 1 125 && nsm->sm_monitored && !nsm->sm_sticky) { 126 dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name); 127 128 status = nsm_mon_unmon(nsm, SM_UNMON, &res); 129 if (status < 0) 130 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", 131 nsm->sm_name); 132 else 133 nsm->sm_monitored = 0; 134 } 135 } 136 137 /* 138 * Create NSM client for the local host 139 */ 140 static struct rpc_clnt * 141 nsm_create(void) 142 { 143 struct sockaddr_in sin = { 144 .sin_family = AF_INET, 145 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 146 .sin_port = 0, 147 }; 148 struct rpc_create_args args = { 149 .protocol = XPRT_TRANSPORT_UDP, 150 .address = (struct sockaddr *)&sin, 151 .addrsize = sizeof(sin), 152 .servername = "localhost", 153 .program = &nsm_program, 154 .version = SM_VERSION, 155 .authflavor = RPC_AUTH_NULL, 156 }; 157 158 return rpc_create(&args); 159 } 160 161 /* 162 * XDR functions for NSM. 163 * 164 * See http://www.opengroup.org/ for details on the Network 165 * Status Monitor wire protocol. 166 */ 167 168 static __be32 *xdr_encode_nsm_string(__be32 *p, char *string) 169 { 170 size_t len = strlen(string); 171 172 if (len > SM_MAXSTRLEN) 173 len = SM_MAXSTRLEN; 174 return xdr_encode_opaque(p, string, len); 175 } 176 177 /* 178 * "mon_name" specifies the host to be monitored. 179 */ 180 static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp) 181 { 182 return xdr_encode_nsm_string(p, argp->mon_name); 183 } 184 185 /* 186 * The "my_id" argument specifies the hostname and RPC procedure 187 * to be called when the status manager receives notification 188 * (via the SM_NOTIFY call) that the state of host "mon_name" 189 * has changed. 190 */ 191 static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp) 192 { 193 p = xdr_encode_nsm_string(p, utsname()->nodename); 194 if (!p) 195 return ERR_PTR(-EIO); 196 197 *p++ = htonl(argp->prog); 198 *p++ = htonl(argp->vers); 199 *p++ = htonl(argp->proc); 200 201 return p; 202 } 203 204 /* 205 * The "mon_id" argument specifies the non-private arguments 206 * of an SM_MON or SM_UNMON call. 207 */ 208 static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp) 209 { 210 p = xdr_encode_mon_name(p, argp); 211 if (!p) 212 return ERR_PTR(-EIO); 213 214 return xdr_encode_my_id(p, argp); 215 } 216 217 /* 218 * The "priv" argument may contain private information required 219 * by the SM_MON call. This information will be supplied in the 220 * SM_NOTIFY call. 221 * 222 * Linux provides the raw IP address of the monitored host, 223 * left in network byte order. 224 */ 225 static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp) 226 { 227 *p++ = argp->addr; 228 *p++ = 0; 229 *p++ = 0; 230 *p++ = 0; 231 232 return p; 233 } 234 235 static int 236 xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 237 { 238 p = xdr_encode_mon_id(p, argp); 239 if (IS_ERR(p)) 240 return PTR_ERR(p); 241 242 p = xdr_encode_priv(p, argp); 243 if (IS_ERR(p)) 244 return PTR_ERR(p); 245 246 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 247 return 0; 248 } 249 250 static int 251 xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 252 { 253 p = xdr_encode_mon_id(p, argp); 254 if (IS_ERR(p)) 255 return PTR_ERR(p); 256 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 257 return 0; 258 } 259 260 static int 261 xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 262 { 263 resp->status = ntohl(*p++); 264 resp->state = ntohl(*p++); 265 dprintk("nsm: xdr_decode_stat_res status %d state %d\n", 266 resp->status, resp->state); 267 return 0; 268 } 269 270 static int 271 xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 272 { 273 resp->state = ntohl(*p++); 274 return 0; 275 } 276 277 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 278 #define SM_my_id_sz (SM_my_name_sz+3) 279 #define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 280 #define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz) 281 #define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE)) 282 #define SM_mon_sz (SM_mon_id_sz+SM_priv_sz) 283 #define SM_monres_sz 2 284 #define SM_unmonres_sz 1 285 286 static struct rpc_procinfo nsm_procedures[] = { 287 [SM_MON] = { 288 .p_proc = SM_MON, 289 .p_encode = (kxdrproc_t) xdr_encode_mon, 290 .p_decode = (kxdrproc_t) xdr_decode_stat_res, 291 .p_arglen = SM_mon_sz, 292 .p_replen = SM_monres_sz, 293 .p_statidx = SM_MON, 294 .p_name = "MONITOR", 295 }, 296 [SM_UNMON] = { 297 .p_proc = SM_UNMON, 298 .p_encode = (kxdrproc_t) xdr_encode_unmon, 299 .p_decode = (kxdrproc_t) xdr_decode_stat, 300 .p_arglen = SM_mon_id_sz, 301 .p_replen = SM_unmonres_sz, 302 .p_statidx = SM_UNMON, 303 .p_name = "UNMONITOR", 304 }, 305 }; 306 307 static struct rpc_version nsm_version1 = { 308 .number = 1, 309 .nrprocs = ARRAY_SIZE(nsm_procedures), 310 .procs = nsm_procedures 311 }; 312 313 static struct rpc_version * nsm_version[] = { 314 [1] = &nsm_version1, 315 }; 316 317 static struct rpc_stat nsm_stats; 318 319 static struct rpc_program nsm_program = { 320 .name = "statd", 321 .number = SM_PROGRAM, 322 .nrvers = ARRAY_SIZE(nsm_version), 323 .version = nsm_version, 324 .stats = &nsm_stats 325 }; 326