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 sockaddr_in      sin = {
 113                 .sin_family     = AF_INET,
 114                 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
 115                 .sin_port       = 0,
 116         };
 117         struct rpc_create_args args = {
 118                 .protocol       = IPPROTO_UDP,
 119                 .address        = (struct sockaddr *)&sin,
 120                 .addrsize       = sizeof(sin),
 121                 .servername     = "localhost",
 122                 .program        = &nsm_program,
 123                 .version        = SM_VERSION,
 124                 .authflavor     = RPC_AUTH_NULL,
 125                 .flags          = (RPC_CLNT_CREATE_ONESHOT),
 126         };
 127
 128         return rpc_create(&args);
 129 }
 130
 131 /*
 132  * XDR functions for NSM.
 133  */
 134
 135 static u32 *
 136 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 137 {
 138         char    buffer[20];
 139
 140         /*
 141          * Use the dotted-quad IP address of the remote host as
 142          * identifier. Linux statd always looks up the canonical
 143          * hostname first for whatever remote hostname it receives,
 144          * so this works alright.
 145          */
 146         sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
 147         if (!(p = xdr_encode_string(p, buffer))
 148          || !(p = xdr_encode_string(p, system_utsname.nodename)))
 149                 return ERR_PTR(-EIO);
 150         *p++ = htonl(argp->prog);
 151         *p++ = htonl(argp->vers);
 152         *p++ = htonl(argp->proc);
 153
 154         return p;
 155 }
 156
 157 static int
 158 xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 159 {
 160         p = xdr_encode_common(rqstp, p, argp);
 161         if (IS_ERR(p))
 162                 return PTR_ERR(p);
 163         *p++ = argp->addr;
 164         *p++ = argp->vers;
 165         *p++ = argp->proto;
 166         *p++ = 0;
 167         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 168         return 0;
 169 }
 170
 171 static int
 172 xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 173 {
 174         p = xdr_encode_common(rqstp, p, argp);
 175         if (IS_ERR(p))
 176                 return PTR_ERR(p);
 177         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 178         return 0;
 179 }
 180
 181 static int
 182 xdr_decode_stat_res(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 183 {
 184         resp->status = ntohl(*p++);
 185         resp->state = ntohl(*p++);
 186         dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
 187                         resp->status, resp->state);
 188         return 0;
 189 }
 190
 191 static int
 192 xdr_decode_stat(struct rpc_rqst *rqstp, u32 *p, struct nsm_res *resp)
 193 {
 194         resp->state = ntohl(*p++);
 195         return 0;
 196 }
 197
 198 #define SM_my_name_sz   (1+XDR_QUADLEN(SM_MAXSTRLEN))
 199 #define SM_my_id_sz     (3+1+SM_my_name_sz)
 200 #define SM_mon_id_sz    (1+XDR_QUADLEN(20)+SM_my_id_sz)
 201 #define SM_mon_sz       (SM_mon_id_sz+4)
 202 #define SM_monres_sz    2
 203 #define SM_unmonres_sz  1
 204
 205 #ifndef MAX
 206 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 207 #endif
 208
 209 static struct rpc_procinfo      nsm_procedures[] = {
 210 [SM_MON] = {
 211                 .p_proc         = SM_MON,
 212                 .p_encode       = (kxdrproc_t) xdr_encode_mon,
 213                 .p_decode       = (kxdrproc_t) xdr_decode_stat_res,
 214                 .p_bufsiz       = MAX(SM_mon_sz, SM_monres_sz) << 2,
 215                 .p_statidx      = SM_MON,
 216                 .p_name         = "MONITOR",
 217         },
 218 [SM_UNMON] = {
 219                 .p_proc         = SM_UNMON,
 220                 .p_encode       = (kxdrproc_t) xdr_encode_unmon,
 221                 .p_decode       = (kxdrproc_t) xdr_decode_stat,
 222                 .p_bufsiz       = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
 223                 .p_statidx      = SM_UNMON,
 224                 .p_name         = "UNMONITOR",
 225         },
 226 };
 227
 228 static struct rpc_version       nsm_version1 = {
 229                 .number         = 1,
 230                 .nrprocs        = ARRAY_SIZE(nsm_procedures),
 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         = ARRAY_SIZE(nsm_version),
 244                 .version        = nsm_version,
 245                 .stats          = &nsm_stats
 246 };