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 struct rpc_message msg = { 40 .rpc_argp = &args, 41 .rpc_resp = res, 42 }; 43 44 clnt = nsm_create(); 45 if (IS_ERR(clnt)) { 46 status = PTR_ERR(clnt); 47 goto out; 48 } 49 50 memset(&args, 0, sizeof(args)); 51 args.mon_name = nsm->sm_name; 52 args.addr = nsm->sm_addr.sin_addr.s_addr; 53 args.prog = NLM_PROGRAM; 54 args.vers = 3; 55 args.proc = NLMPROC_NSM_NOTIFY; 56 memset(res, 0, sizeof(*res)); 57 58 msg.rpc_proc = &clnt->cl_procinfo[proc]; 59 status = rpc_call_sync(clnt, &msg, 0); 60 if (status < 0) 61 printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n", 62 status); 63 else 64 status = 0; 65 rpc_shutdown_client(clnt); 66 out: 67 return status; 68 } 69 70 /* 71 * Set up monitoring of a remote host 72 */ 73 int 74 nsm_monitor(struct nlm_host *host) 75 { 76 struct nsm_handle *nsm = host->h_nsmhandle; 77 struct nsm_res res; 78 int status; 79 80 dprintk("lockd: nsm_monitor(%s)\n", host->h_name); 81 BUG_ON(nsm == NULL); 82 83 if (nsm->sm_monitored) 84 return 0; 85 86 status = nsm_mon_unmon(nsm, SM_MON, &res); 87 88 if (status < 0 || res.status != 0) 89 printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name); 90 else 91 nsm->sm_monitored = 1; 92 return status; 93 } 94 95 /* 96 * Cease to monitor remote host 97 */ 98 int 99 nsm_unmonitor(struct nlm_host *host) 100 { 101 struct nsm_handle *nsm = host->h_nsmhandle; 102 struct nsm_res res; 103 int status = 0; 104 105 if (nsm == NULL) 106 return 0; 107 host->h_nsmhandle = NULL; 108 109 if (atomic_read(&nsm->sm_count) == 1 110 && nsm->sm_monitored && !nsm->sm_sticky) { 111 dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); 112 113 status = nsm_mon_unmon(nsm, SM_UNMON, &res); 114 if (status < 0) 115 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", 116 host->h_name); 117 else 118 nsm->sm_monitored = 0; 119 } 120 nsm_release(nsm); 121 return status; 122 } 123 124 /* 125 * Create NSM client for the local host 126 */ 127 static struct rpc_clnt * 128 nsm_create(void) 129 { 130 struct sockaddr_in sin = { 131 .sin_family = AF_INET, 132 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 133 .sin_port = 0, 134 }; 135 struct rpc_create_args args = { 136 .protocol = XPRT_TRANSPORT_UDP, 137 .address = (struct sockaddr *)&sin, 138 .addrsize = sizeof(sin), 139 .servername = "localhost", 140 .program = &nsm_program, 141 .version = SM_VERSION, 142 .authflavor = RPC_AUTH_NULL, 143 }; 144 145 return rpc_create(&args); 146 } 147 148 /* 149 * XDR functions for NSM. 150 */ 151 152 static __be32 * 153 xdr_encode_common(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 154 { 155 char buffer[20], *name; 156 157 /* 158 * Use the dotted-quad IP address of the remote host as 159 * identifier. Linux statd always looks up the canonical 160 * hostname first for whatever remote hostname it receives, 161 * so this works alright. 162 */ 163 if (nsm_use_hostnames) { 164 name = argp->mon_name; 165 } else { 166 sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr)); 167 name = buffer; 168 } 169 if (!(p = xdr_encode_string(p, name)) 170 || !(p = xdr_encode_string(p, utsname()->nodename))) 171 return ERR_PTR(-EIO); 172 *p++ = htonl(argp->prog); 173 *p++ = htonl(argp->vers); 174 *p++ = htonl(argp->proc); 175 176 return p; 177 } 178 179 static int 180 xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 181 { 182 p = xdr_encode_common(rqstp, p, argp); 183 if (IS_ERR(p)) 184 return PTR_ERR(p); 185 186 /* Surprise - there may even be room for an IPv6 address now */ 187 *p++ = argp->addr; 188 *p++ = 0; 189 *p++ = 0; 190 *p++ = 0; 191 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 192 return 0; 193 } 194 195 static int 196 xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 197 { 198 p = xdr_encode_common(rqstp, p, argp); 199 if (IS_ERR(p)) 200 return PTR_ERR(p); 201 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 202 return 0; 203 } 204 205 static int 206 xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 207 { 208 resp->status = ntohl(*p++); 209 resp->state = ntohl(*p++); 210 dprintk("nsm: xdr_decode_stat_res status %d state %d\n", 211 resp->status, resp->state); 212 return 0; 213 } 214 215 static int 216 xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 217 { 218 resp->state = ntohl(*p++); 219 return 0; 220 } 221 222 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 223 #define SM_my_id_sz (3+1+SM_my_name_sz) 224 #define SM_mon_id_sz (1+XDR_QUADLEN(20)+SM_my_id_sz) 225 #define SM_mon_sz (SM_mon_id_sz+4) 226 #define SM_monres_sz 2 227 #define SM_unmonres_sz 1 228 229 static struct rpc_procinfo nsm_procedures[] = { 230 [SM_MON] = { 231 .p_proc = SM_MON, 232 .p_encode = (kxdrproc_t) xdr_encode_mon, 233 .p_decode = (kxdrproc_t) xdr_decode_stat_res, 234 .p_arglen = SM_mon_sz, 235 .p_replen = SM_monres_sz, 236 .p_statidx = SM_MON, 237 .p_name = "MONITOR", 238 }, 239 [SM_UNMON] = { 240 .p_proc = SM_UNMON, 241 .p_encode = (kxdrproc_t) xdr_encode_unmon, 242 .p_decode = (kxdrproc_t) xdr_decode_stat, 243 .p_arglen = SM_mon_id_sz, 244 .p_replen = SM_unmonres_sz, 245 .p_statidx = SM_UNMON, 246 .p_name = "UNMONITOR", 247 }, 248 }; 249 250 static struct rpc_version nsm_version1 = { 251 .number = 1, 252 .nrprocs = ARRAY_SIZE(nsm_procedures), 253 .procs = nsm_procedures 254 }; 255 256 static struct rpc_version * nsm_version[] = { 257 [1] = &nsm_version1, 258 }; 259 260 static struct rpc_stat nsm_stats; 261 262 static struct rpc_program nsm_program = { 263 .name = "statd", 264 .number = SM_PROGRAM, 265 .nrvers = ARRAY_SIZE(nsm_version), 266 .version = nsm_version, 267 .stats = &nsm_stats 268 }; 269