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 int nsm_local_state; 28 29 /* 30 * Common procedure for SM_MON/SM_UNMON calls 31 */ 32 static int 33 nsm_mon_unmon(struct nsm_handle *nsm, 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 memset(&args, 0, sizeof(args)); 50 args.mon_name = nsm->sm_name; 51 args.addr = nsm->sm_addr.sin_addr.s_addr; 52 args.prog = NLM_PROGRAM; 53 args.vers = 3; 54 args.proc = NLMPROC_NSM_NOTIFY; 55 memset(res, 0, sizeof(*res)); 56 57 msg.rpc_proc = &clnt->cl_procinfo[proc]; 58 status = rpc_call_sync(clnt, &msg, 0); 59 if (status < 0) 60 printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n", 61 status); 62 else 63 status = 0; 64 out: 65 return status; 66 } 67 68 /* 69 * Set up monitoring of a remote host 70 */ 71 int 72 nsm_monitor(struct nlm_host *host) 73 { 74 struct nsm_handle *nsm = host->h_nsmhandle; 75 struct nsm_res res; 76 int status; 77 78 dprintk("lockd: nsm_monitor(%s)\n", host->h_name); 79 BUG_ON(nsm == NULL); 80 81 if (nsm->sm_monitored) 82 return 0; 83 84 status = nsm_mon_unmon(nsm, SM_MON, &res); 85 86 if (status < 0 || res.status != 0) 87 printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name); 88 else 89 nsm->sm_monitored = 1; 90 return status; 91 } 92 93 /* 94 * Cease to monitor remote host 95 */ 96 int 97 nsm_unmonitor(struct nlm_host *host) 98 { 99 struct nsm_handle *nsm = host->h_nsmhandle; 100 struct nsm_res res; 101 int status = 0; 102 103 if (nsm == NULL) 104 return 0; 105 host->h_nsmhandle = NULL; 106 107 if (atomic_read(&nsm->sm_count) == 1 108 && nsm->sm_monitored && !nsm->sm_sticky) { 109 dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); 110 111 status = nsm_mon_unmon(nsm, SM_UNMON, &res); 112 if (status < 0) 113 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", 114 host->h_name); 115 else 116 nsm->sm_monitored = 0; 117 } 118 nsm_release(nsm); 119 return status; 120 } 121 122 /* 123 * Create NSM client for the local host 124 */ 125 static struct rpc_clnt * 126 nsm_create(void) 127 { 128 struct sockaddr_in sin = { 129 .sin_family = AF_INET, 130 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 131 .sin_port = 0, 132 }; 133 struct rpc_create_args args = { 134 .protocol = IPPROTO_UDP, 135 .address = (struct sockaddr *)&sin, 136 .addrsize = sizeof(sin), 137 .servername = "localhost", 138 .program = &nsm_program, 139 .version = SM_VERSION, 140 .authflavor = RPC_AUTH_NULL, 141 .flags = (RPC_CLNT_CREATE_ONESHOT), 142 }; 143 144 return rpc_create(&args); 145 } 146 147 /* 148 * XDR functions for NSM. 149 */ 150 151 static __be32 * 152 xdr_encode_common(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 153 { 154 char buffer[20], *name; 155 156 /* 157 * Use the dotted-quad IP address of the remote host as 158 * identifier. Linux statd always looks up the canonical 159 * hostname first for whatever remote hostname it receives, 160 * so this works alright. 161 */ 162 if (nsm_use_hostnames) { 163 name = argp->mon_name; 164 } else { 165 sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr)); 166 name = buffer; 167 } 168 if (!(p = xdr_encode_string(p, name)) 169 || !(p = xdr_encode_string(p, utsname()->nodename))) 170 return ERR_PTR(-EIO); 171 *p++ = htonl(argp->prog); 172 *p++ = htonl(argp->vers); 173 *p++ = htonl(argp->proc); 174 175 return p; 176 } 177 178 static int 179 xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 180 { 181 p = xdr_encode_common(rqstp, p, argp); 182 if (IS_ERR(p)) 183 return PTR_ERR(p); 184 185 /* Surprise - there may even be room for an IPv6 address now */ 186 *p++ = argp->addr; 187 *p++ = 0; 188 *p++ = 0; 189 *p++ = 0; 190 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 191 return 0; 192 } 193 194 static int 195 xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp) 196 { 197 p = xdr_encode_common(rqstp, p, argp); 198 if (IS_ERR(p)) 199 return PTR_ERR(p); 200 rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p); 201 return 0; 202 } 203 204 static int 205 xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 206 { 207 resp->status = ntohl(*p++); 208 resp->state = ntohl(*p++); 209 dprintk("nsm: xdr_decode_stat_res status %d state %d\n", 210 resp->status, resp->state); 211 return 0; 212 } 213 214 static int 215 xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp) 216 { 217 resp->state = ntohl(*p++); 218 return 0; 219 } 220 221 #define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN)) 222 #define SM_my_id_sz (3+1+SM_my_name_sz) 223 #define SM_mon_id_sz (1+XDR_QUADLEN(20)+SM_my_id_sz) 224 #define SM_mon_sz (SM_mon_id_sz+4) 225 #define SM_monres_sz 2 226 #define SM_unmonres_sz 1 227 228 static struct rpc_procinfo nsm_procedures[] = { 229 [SM_MON] = { 230 .p_proc = SM_MON, 231 .p_encode = (kxdrproc_t) xdr_encode_mon, 232 .p_decode = (kxdrproc_t) xdr_decode_stat_res, 233 .p_arglen = SM_mon_sz, 234 .p_replen = SM_monres_sz, 235 .p_statidx = SM_MON, 236 .p_name = "MONITOR", 237 }, 238 [SM_UNMON] = { 239 .p_proc = SM_UNMON, 240 .p_encode = (kxdrproc_t) xdr_encode_unmon, 241 .p_decode = (kxdrproc_t) xdr_decode_stat, 242 .p_arglen = SM_mon_id_sz, 243 .p_replen = SM_unmonres_sz, 244 .p_statidx = SM_UNMON, 245 .p_name = "UNMONITOR", 246 }, 247 }; 248 249 static struct rpc_version nsm_version1 = { 250 .number = 1, 251 .nrprocs = ARRAY_SIZE(nsm_procedures), 252 .procs = nsm_procedures 253 }; 254 255 static struct rpc_version * nsm_version[] = { 256 [1] = &nsm_version1, 257 }; 258 259 static struct rpc_stat nsm_stats; 260 261 static struct rpc_program nsm_program = { 262 .name = "statd", 263 .number = SM_PROGRAM, 264 .nrvers = ARRAY_SIZE(nsm_version), 265 .version = nsm_version, 266 .stats = &nsm_stats 267 }; 268