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         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         args.addr = host->h_addr.sin_addr.s_addr;
  50         args.proto= (host->h_proto<<1) | host->h_server;
  51         args.prog = NLM_PROGRAM;
  52         args.vers = host->h_version;
  53         args.proc = NLMPROC_NSM_NOTIFY;
  54         memset(res, 0, sizeof(*res));
  55
  56         msg.rpc_proc = &clnt->cl_procinfo[proc];
  57         status = rpc_call_sync(clnt, &msg, 0);
  58         if (status < 0)
  59                 printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
  60                         status);
  61         else
  62                 status = 0;
  63  out:
  64         return status;
  65 }
  66
  67 /*
  68  * Set up monitoring of a remote host
  69  */
  70 int
  71 nsm_monitor(struct nlm_host *host)
  72 {
  73         struct nsm_res  res;
  74         int             status;
  75
  76         dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
  77
  78         status = nsm_mon_unmon(host, SM_MON, &res);
  79
  80         if (status < 0 || res.status != 0)
  81                 printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
  82         else
  83                 host->h_monitored = 1;
  84         return status;
  85 }
  86
  87 /*
  88  * Cease to monitor remote host
  89  */
  90 int
  91 nsm_unmonitor(struct nlm_host *host)
  92 {
  93         struct nsm_res  res;
  94         int             status;
  95
  96         dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
  97
  98         status = nsm_mon_unmon(host, SM_UNMON, &res);
  99         if (status < 0)
 100                 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name);
 101         else
 102                 host->h_monitored = 0;
 103         return status;
 104 }
 105
 106 /*
 107  * Create NSM client for the local host
 108  */
 109 static struct rpc_clnt *
 110 nsm_create(void)
 111 {
 112         struct rpc_xprt         *xprt;
 113         struct rpc_clnt         *clnt;
 114         struct sockaddr_in      sin;
 115
 116         sin.sin_family = AF_INET;
 117         sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 118         sin.sin_port = 0;
 119
 120         xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
 121         if (IS_ERR(xprt))
 122                 return (struct rpc_clnt *)xprt;
 123         xprt->resvport = 1;     /* NSM requires a reserved port */
 124
 125         clnt = rpc_create_client(xprt, "localhost",
 126                                 &nsm_program, SM_VERSION,
 127                                 RPC_AUTH_NULL);
 128         if (IS_ERR(clnt))
 129                 goto out_err;
 130         clnt->cl_softrtry = 1;
 131         clnt->cl_oneshot  = 1;
 132         return clnt;
 133
 134 out_err:
 135         return clnt;
 136 }
 137
 138 /*
 139  * XDR functions for NSM.
 140  */
 141
 142 static u32 *
 143 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 144 {
 145         char    buffer[20];
 146
 147         /*
 148          * Use the dotted-quad IP address of the remote host as
 149          * identifier. Linux statd always looks up the canonical
 150          * hostname first for whatever remote hostname it receives,
 151          * so this works alright.
 152          */
 153         sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
 154         if (!(p = xdr_encode_string(p, buffer))
 155          || !(p = xdr_encode_string(p, system_utsname.nodename)))
 156                 return ERR_PTR(-EIO);
 157         *p++ = htonl(argp->prog);
 158         *p++ = htonl(argp->vers);
 159         *p++ = htonl(argp->proc);
 160
 161         return p;
 162 }
 163
 164 static int
 165 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 166 {
 167         p = xdr_encode_common(rqstp, p, argp);
 168         if (IS_ERR(p))
 169                 return PTR_ERR(p);
 170         *p++ = argp->addr;
 171         *p++ = argp->vers;
 172         *p++ = argp->proto;
 173         *p++ = 0;
 174         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 175         return 0;
 176 }
 177
 178 static int
 179 xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *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         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 185         return 0;
 186 }
 187
 188 static int
 189 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 190 {
 191         resp->status = ntohl(*p++);
 192         resp->state = ntohl(*p++);
 193         dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
 194                         resp->status, resp->state);
 195         return 0;
 196 }
 197
 198 static int
 199 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 200 {
 201         resp->state = ntohl(*p++);
 202         return 0;
 203 }
 204
 205 #define SM_my_name_sz   (1+XDR_QUADLEN(SM_MAXSTRLEN))
 206 #define SM_my_id_sz     (3+1+SM_my_name_sz)
 207 #define SM_mon_id_sz    (1+XDR_QUADLEN(20)+SM_my_id_sz)
 208 #define SM_mon_sz       (SM_mon_id_sz+4)
 209 #define SM_monres_sz    2
 210 #define SM_unmonres_sz  1
 211
 212 #ifndef MAX
 213 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 214 #endif
 215
 216 static struct rpc_procinfo      nsm_procedures[] = {
 217 [SM_MON] = {
 218                 .p_proc         = SM_MON,
 219                 .p_encode       = (kxdrproc_t) xdr_encode_mon,
 220                 .p_decode       = (kxdrproc_t) xdr_decode_stat_res,
 221                 .p_bufsiz       = MAX(SM_mon_sz, SM_monres_sz) << 2,
 222                 .p_statidx      = SM_MON,
 223                 .p_name         = "MONITOR",
 224         },
 225 [SM_UNMON] = {
 226                 .p_proc         = SM_UNMON,
 227                 .p_encode       = (kxdrproc_t) xdr_encode_unmon,
 228                 .p_decode       = (kxdrproc_t) xdr_decode_stat,
 229                 .p_bufsiz       = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
 230                 .p_statidx      = SM_UNMON,
 231                 .p_name         = "UNMONITOR",
 232         },
 233 };
 234
 235 static struct rpc_version       nsm_version1 = {
 236                 .number         = 1,
 237                 .nrprocs        = ARRAY_SIZE(nsm_procedures),
 238                 .procs          = nsm_procedures
 239 };
 240
 241 static struct rpc_version *     nsm_version[] = {
 242         [1] = &nsm_version1,
 243 };
 244
 245 static struct rpc_stat          nsm_stats;
 246
 247 static struct rpc_program       nsm_program = {
 248                 .name           = "statd",
 249                 .number         = SM_PROGRAM,
 250                 .nrvers         = ARRAY_SIZE(nsm_version),
 251                 .version        = nsm_version,
 252                 .stats          = &nsm_stats
 253 };