fs/lockd/mon.c

   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 };