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/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
 119         clnt = rpc_create_client(xprt, "localhost",
 120                                 &nsm_program, SM_VERSION,
 121                                 RPC_AUTH_NULL);
 122         if (IS_ERR(clnt))
 123                 goto out_destroy;
 124         clnt->cl_softrtry = 1;
 125         clnt->cl_chatty   = 1;
 126         clnt->cl_oneshot  = 1;
 127         xprt->resvport = 1;     /* NSM requires a reserved port */
 128         return clnt;
 129
 130 out_destroy:
 131         xprt_destroy(xprt);
 132         return clnt;
 133 }
 134
 135 /*
 136  * XDR functions for NSM.
 137  */
 138
 139 static u32 *
 140 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 141 {
 142         char    buffer[20];
 143
 144         /*
 145          * Use the dotted-quad IP address of the remote host as
 146          * identifier. Linux statd always looks up the canonical
 147          * hostname first for whatever remote hostname it receives,
 148          * so this works alright.
 149          */
 150         sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
 151         if (!(p = xdr_encode_string(p, buffer))
 152          || !(p = xdr_encode_string(p, system_utsname.nodename)))
 153                 return ERR_PTR(-EIO);
 154         *p++ = htonl(argp->prog);
 155         *p++ = htonl(argp->vers);
 156         *p++ = htonl(argp->proc);
 157
 158         return p;
 159 }
 160
 161 static int
 162 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 163 {
 164         p = xdr_encode_common(rqstp, p, argp);
 165         if (IS_ERR(p))
 166                 return PTR_ERR(p);
 167         *p++ = argp->addr;
 168         *p++ = argp->vers;
 169         *p++ = argp->proto;
 170         *p++ = 0;
 171         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 172         return 0;
 173 }
 174
 175 static int
 176 xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 177 {
 178         p = xdr_encode_common(rqstp, p, argp);
 179         if (IS_ERR(p))
 180                 return PTR_ERR(p);
 181         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 182         return 0;
 183 }
 184
 185 static int
 186 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 187 {
 188         resp->status = ntohl(*p++);
 189         resp->state = ntohl(*p++);
 190         dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
 191                         resp->status, resp->state);
 192         return 0;
 193 }
 194
 195 static int
 196 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 197 {
 198         resp->state = ntohl(*p++);
 199         return 0;
 200 }
 201
 202 #define SM_my_name_sz   (1+XDR_QUADLEN(SM_MAXSTRLEN))
 203 #define SM_my_id_sz     (3+1+SM_my_name_sz)
 204 #define SM_mon_id_sz    (1+XDR_QUADLEN(20)+SM_my_id_sz)
 205 #define SM_mon_sz       (SM_mon_id_sz+4)
 206 #define SM_monres_sz    2
 207 #define SM_unmonres_sz  1
 208
 209 #ifndef MAX
 210 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 211 #endif
 212
 213 static struct rpc_procinfo      nsm_procedures[] = {
 214 [SM_MON] = {
 215                 .p_proc         = SM_MON,
 216                 .p_encode       = (kxdrproc_t) xdr_encode_mon,
 217                 .p_decode       = (kxdrproc_t) xdr_decode_stat_res,
 218                 .p_bufsiz       = MAX(SM_mon_sz, SM_monres_sz) << 2,
 219         },
 220 [SM_UNMON] = {
 221                 .p_proc         = SM_UNMON,
 222                 .p_encode       = (kxdrproc_t) xdr_encode_unmon,
 223                 .p_decode       = (kxdrproc_t) xdr_decode_stat,
 224                 .p_bufsiz       = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
 225         },
 226 };
 227
 228 static struct rpc_version       nsm_version1 = {
 229                 .number         = 1,
 230                 .nrprocs        = sizeof(nsm_procedures)/sizeof(nsm_procedures[0]),
 231                 .procs          = nsm_procedures
 232 };
 233
 234 static struct rpc_version *     nsm_version[] = {
 235         [1] = &nsm_version1,
 236 };
 237
 238 static struct rpc_stat          nsm_stats;
 239
 240 static struct rpc_program       nsm_program = {
 241                 .name           = "statd",
 242                 .number         = SM_PROGRAM,
 243                 .nrvers         = sizeof(nsm_version)/sizeof(nsm_version[0]),
 244                 .version        = nsm_version,
 245                 .stats          = &nsm_stats
 246 };