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 #if 0   // mask by Victor Yu. 02-12-2007
 131                 .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
 132                 .sin_port       = 0,
 133 #endif
 134         };
 135         struct rpc_create_args args = {
 136                 .protocol       = IPPROTO_UDP,
 137                 .address        = (struct sockaddr *)&sin,
 138                 .addrsize       = sizeof(sin),
 139                 .servername     = "localhost",
 140                 .program        = &nsm_program,
 141                 .version        = SM_VERSION,
 142                 .authflavor     = RPC_AUTH_NULL,
 143                 .flags          = (RPC_CLNT_CREATE_ONESHOT),
 144         };
 145
 146 #if 1   // add by Victor Yu. 02-12-2007
 147         sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 148         sin.sin_port = 0;
 149 #endif
 150         return rpc_create(&args);
 151 }
 152
 153 /*
 154  * XDR functions for NSM.
 155  */
 156
 157 static __be32 *
 158 xdr_encode_common(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
 159 {
 160         char    buffer[20], *name;
 161
 162         /*
 163          * Use the dotted-quad IP address of the remote host as
 164          * identifier. Linux statd always looks up the canonical
 165          * hostname first for whatever remote hostname it receives,
 166          * so this works alright.
 167          */
 168         if (nsm_use_hostnames) {
 169                 name = argp->mon_name;
 170         } else {
 171                 sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
 172                 name = buffer;
 173         }
 174         if (!(p = xdr_encode_string(p, name))
 175          || !(p = xdr_encode_string(p, utsname()->nodename)))
 176                 return ERR_PTR(-EIO);
 177         *p++ = htonl(argp->prog);
 178         *p++ = htonl(argp->vers);
 179         *p++ = htonl(argp->proc);
 180
 181         return p;
 182 }
 183
 184 static int
 185 xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
 186 {
 187         p = xdr_encode_common(rqstp, p, argp);
 188         if (IS_ERR(p))
 189                 return PTR_ERR(p);
 190
 191         /* Surprise - there may even be room for an IPv6 address now */
 192         *p++ = argp->addr;
 193         *p++ = 0;
 194         *p++ = 0;
 195         *p++ = 0;
 196         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 197         return 0;
 198 }
 199
 200 static int
 201 xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
 202 {
 203         p = xdr_encode_common(rqstp, p, argp);
 204         if (IS_ERR(p))
 205                 return PTR_ERR(p);
 206         rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
 207         return 0;
 208 }
 209
 210 static int
 211 xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
 212 {
 213         resp->status = ntohl(*p++);
 214         resp->state = ntohl(*p++);
 215         dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
 216                         resp->status, resp->state);
 217         return 0;
 218 }
 219
 220 static int
 221 xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
 222 {
 223         resp->state = ntohl(*p++);
 224         return 0;
 225 }
 226
 227 #define SM_my_name_sz   (1+XDR_QUADLEN(SM_MAXSTRLEN))
 228 #define SM_my_id_sz     (3+1+SM_my_name_sz)
 229 #define SM_mon_id_sz    (1+XDR_QUADLEN(20)+SM_my_id_sz)
 230 #define SM_mon_sz       (SM_mon_id_sz+4)
 231 #define SM_monres_sz    2
 232 #define SM_unmonres_sz  1
 233
 234 #ifndef MAX
 235 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 236 #endif
 237
 238 static struct rpc_procinfo      nsm_procedures[] = {
 239 [SM_MON] = {
 240                 .p_proc         = SM_MON,
 241                 .p_encode       = (kxdrproc_t) xdr_encode_mon,
 242                 .p_decode       = (kxdrproc_t) xdr_decode_stat_res,
 243                 .p_bufsiz       = MAX(SM_mon_sz, SM_monres_sz) << 2,
 244                 .p_statidx      = SM_MON,
 245                 .p_name         = "MONITOR",
 246         },
 247 [SM_UNMON] = {
 248                 .p_proc         = SM_UNMON,
 249                 .p_encode       = (kxdrproc_t) xdr_encode_unmon,
 250                 .p_decode       = (kxdrproc_t) xdr_decode_stat,
 251                 .p_bufsiz       = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
 252                 .p_statidx      = SM_UNMON,
 253                 .p_name         = "UNMONITOR",
 254         },
 255 };
 256
 257 static struct rpc_version       nsm_version1 = {
 258                 .number         = 1,
 259                 .nrprocs        = ARRAY_SIZE(nsm_procedures),
 260                 .procs          = nsm_procedures
 261 };
 262
 263 static struct rpc_version *     nsm_version[] = {
 264         [1] = &nsm_version1,
 265 };
 266
 267 static struct rpc_stat          nsm_stats;
 268
 269 static struct rpc_program       nsm_program = {
 270                 .name           = "statd",
 271                 .number         = SM_PROGRAM,
 272                 .nrvers         = ARRAY_SIZE(nsm_version),
 273                 .version        = nsm_version,
 274                 .stats          = &nsm_stats
 275 };