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