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 extern 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         status = -EACCES;
  40         clnt = nsm_create();
  41         if (!clnt)
  42                 goto out;
  43
  44         args.addr = host->h_addr.sin_addr.s_addr;
  45         args.prog = NLM_PROGRAM;
  46         args.vers = 1;
  47         args.proc = NLMPROC_NSM_NOTIFY;
  48         memset(res, 0, sizeof(*res));
  49
  50         status = rpc_call(clnt, proc, &args, res, 0);
  51         if (status < 0)
  52                 printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
  53                         status);
  54         else
  55                 status = 0;
  56  out:
  57         return status;
  58 }
  59
  60 /*
  61  * Set up monitoring of a remote host
  62  */
  63 int
  64 nsm_monitor(struct nlm_host *host)
  65 {
  66         struct nsm_res  res;
  67         int             status;
  68
  69         dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
  70
  71         status = nsm_mon_unmon(host, SM_MON, &res);
  72
  73         if (status < 0 || res.status != 0)
  74                 printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
  75         else
  76                 host->h_monitored = 1;
  77         return status;
  78 }
  79
  80 /*
  81  * Cease to monitor remote host
  82  */
  83 int
  84 nsm_unmonitor(struct nlm_host *host)
  85 {
  86         struct nsm_res  res;
  87         int             status;
  88
  89         dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
  90
  91         status = nsm_mon_unmon(host, SM_UNMON, &res);
  92         if (status < 0)
  93                 printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name);
  94         else
  95                 host->h_monitored = 0;
  96         return status;
  97 }
  98
  99 /*
 100  * Create NSM client for the local host
 101  */
 102 static struct rpc_clnt *
 103 nsm_create(void)
 104 {
 105         struct rpc_xprt         *xprt;
 106         struct rpc_clnt         *clnt = NULL;
 107         struct sockaddr_in      sin;
 108
 109         sin.sin_family = AF_INET;
 110         sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 111         sin.sin_port = 0;
 112
 113         xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
 114         if (!xprt)
 115                 goto out;
 116
 117         clnt = rpc_create_client(xprt, "localhost",
 118                                 &nsm_program, SM_VERSION,
 119                                 RPC_AUTH_NULL);
 120         if (!clnt)
 121                 goto out_destroy;
 122         clnt->cl_softrtry = 1;
 123         clnt->cl_chatty   = 1;
 124         clnt->cl_oneshot  = 1;
 125 out:
 126         return clnt;
 127
 128 out_destroy:
 129         xprt_destroy(xprt);
 130         goto out;
 131 }
 132
 133 /*
 134  * XDR functions for NSM.
 135  */
 136 static int
 137 xdr_error(struct rpc_rqst *rqstp, u32 *p, void *dummy)
 138 {
 139         return -EACCES;
 140 }
 141
 142 static int
 143 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 144 {
 145         char    buffer[20];
 146         u32     addr = ntohl(argp->addr);
 147
 148         dprintk("nsm: xdr_encode_mon(%08x, %d, %d, %d)\n",
 149                         htonl(argp->addr), htonl(argp->proc),
 150                         htonl(argp->vers), htonl(argp->proc));
 151
 152         /*
 153          * Use the dotted-quad IP address of the remote host as
 154          * identifier. Linux statd always looks up the canonical
 155          * hostname first for whatever remote hostname it receives,
 156          * so this works alright.
 157          */
 158         sprintf(buffer, "%d.%d.%d.%d", (addr>>24) & 0xff, (addr>>16) & 0xff,
 159                                         (addr>>8) & 0xff,  (addr) & 0xff);
 160         if (!(p = xdr_encode_string(p, buffer))
 161          || !(p = xdr_encode_string(p, system_utsname.nodename)))
 162                 return -EIO;
 163         *p++ = htonl(argp->prog);
 164         *p++ = htonl(argp->vers);
 165         *p++ = htonl(argp->proc);
 166
 167         /* This is the private part. Needed only for SM_MON call */
 168         if (rqstp->rq_task->tk_msg.rpc_proc == SM_MON) {
 169                 *p++ = argp->addr;
 170                 *p++ = 0;
 171                 *p++ = 0;
 172                 *p++ = 0;
 173         }
 174
 175         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 176         return 0;
 177 }
 178
 179 static int
 180 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 181 {
 182         resp->status = ntohl(*p++);
 183         resp->state = ntohl(*p++);
 184         dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
 185                         resp->status, resp->state);
 186         return 0;
 187 }
 188
 189 static int
 190 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 191 {
 192         resp->state = ntohl(*p++);
 193         return 0;
 194 }
 195
 196 #define SM_my_name_sz   (1+XDR_QUADLEN(SM_MAXSTRLEN))
 197 #define SM_my_id_sz     (3+1+SM_my_name_sz)
 198 #define SM_mon_id_sz    (1+XDR_QUADLEN(20)+SM_my_id_sz)
 199 #define SM_mon_sz       (SM_mon_id_sz+4)
 200 #define SM_monres_sz    2
 201 #define SM_unmonres_sz  1
 202
 203 #ifndef MAX
 204 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 205 #endif
 206
 207 static struct rpc_procinfo      nsm_procedures[] = {
 208         { "sm_null",
 209                 (kxdrproc_t) xdr_error,
 210                 (kxdrproc_t) xdr_error, 0, 0 },
 211         { "sm_stat",
 212                 (kxdrproc_t) xdr_error,
 213                 (kxdrproc_t) xdr_error, 0, 0 },
 214         { "sm_mon",
 215                 (kxdrproc_t) xdr_encode_mon,
 216                 (kxdrproc_t) xdr_decode_stat_res, MAX(SM_mon_sz, SM_monres_sz) << 2, 0 },
 217         { "sm_unmon",
 218                 (kxdrproc_t) xdr_encode_mon,
 219                 (kxdrproc_t) xdr_decode_stat, MAX(SM_mon_id_sz, SM_unmonres_sz) << 2, 0 },
 220         { "sm_unmon_all",
 221                 (kxdrproc_t) xdr_error,
 222                 (kxdrproc_t) xdr_error, 0, 0 },
 223         { "sm_simu_crash",
 224                 (kxdrproc_t) xdr_error,
 225                 (kxdrproc_t) xdr_error, 0, 0 },
 226         { "sm_notify",
 227                 (kxdrproc_t) xdr_error,
 228                 (kxdrproc_t) xdr_error, 0, 0 },
 229 };
 230
 231 static struct rpc_version       nsm_version1 = {
 232         1,
 233         sizeof(nsm_procedures)/sizeof(nsm_procedures[0]),
 234         nsm_procedures
 235 };
 236
 237 static struct rpc_version *     nsm_version[] = {
 238         NULL,
 239         &nsm_version1,
 240 };
 241
 242 static struct rpc_stat          nsm_stats;
 243
 244 struct rpc_program              nsm_program = {
 245         "statd",
 246         SM_PROGRAM,
 247         sizeof(nsm_version)/sizeof(nsm_version[0]),
 248         nsm_version,
 249         &nsm_stats
 250 };