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 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 };