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DEFINITIONS
This source file includes following definitions.
- nsm_mon_unmon
- nsm_monitor
- nsm_unmonitor
- nsm_create
- xdr_encode_nsm_string
- xdr_encode_mon_name
- xdr_encode_my_id
- xdr_encode_mon_id
- xdr_encode_priv
- xdr_encode_mon
- xdr_encode_unmon
- xdr_decode_stat_res
- xdr_decode_stat
/*
* linux/fs/lockd/mon.c
*
* The kernel statd client.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>
#define NLMDBG_FACILITY NLMDBG_MONITOR
#define XDR_ADDRBUF_LEN (20)
static struct rpc_clnt * nsm_create(void);
static struct rpc_program nsm_program;
/*
* Local NSM state
*/
int nsm_local_state;
/*
* Common procedure for SM_MON/SM_UNMON calls
*/
static int
nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
{
struct rpc_clnt *clnt;
int status;
struct nsm_args args;
struct rpc_message msg = {
.rpc_argp = &args,
.rpc_resp = res,
};
clnt = nsm_create();
if (IS_ERR(clnt)) {
status = PTR_ERR(clnt);
goto out;
}
memset(&args, 0, sizeof(args));
args.mon_name = nsm->sm_name;
args.addr = nsm_addr_in(nsm)->sin_addr.s_addr;
args.prog = NLM_PROGRAM;
args.vers = 3;
args.proc = NLMPROC_NSM_NOTIFY;
memset(res, 0, sizeof(*res));
msg.rpc_proc = &clnt->cl_procinfo[proc];
status = rpc_call_sync(clnt, &msg, 0);
if (status < 0)
printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
status);
else
status = 0;
rpc_shutdown_client(clnt);
out:
return status;
}
/*
* Set up monitoring of a remote host
*/
int
nsm_monitor(struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status;
dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
BUG_ON(nsm == NULL);
if (nsm->sm_monitored)
return 0;
status = nsm_mon_unmon(nsm, SM_MON, &res);
if (status < 0 || res.status != 0)
printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
else
nsm->sm_monitored = 1;
return status;
}
/*
* Cease to monitor remote host
*/
int
nsm_unmonitor(struct nlm_host *host)
{
struct nsm_handle *nsm = host->h_nsmhandle;
struct nsm_res res;
int status = 0;
if (nsm == NULL)
return 0;
host->h_nsmhandle = NULL;
if (atomic_read(&nsm->sm_count) == 1
&& nsm->sm_monitored && !nsm->sm_sticky) {
dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
status = nsm_mon_unmon(nsm, SM_UNMON, &res);
if (status < 0)
printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
host->h_name);
else
nsm->sm_monitored = 0;
}
nsm_release(nsm);
return status;
}
/*
* Create NSM client for the local host
*/
static struct rpc_clnt *
nsm_create(void)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
.sin_port = 0,
};
struct rpc_create_args args = {
.protocol = XPRT_TRANSPORT_UDP,
.address = (struct sockaddr *)&sin,
.addrsize = sizeof(sin),
.servername = "localhost",
.program = &nsm_program,
.version = SM_VERSION,
.authflavor = RPC_AUTH_NULL,
};
return rpc_create(&args);
}
/*
* XDR functions for NSM.
*
* See http://www.opengroup.org/ for details on the Network
* Status Monitor wire protocol.
*/
static __be32 *xdr_encode_nsm_string(__be32 *p, char *string)
{
size_t len = strlen(string);
if (len > SM_MAXSTRLEN)
len = SM_MAXSTRLEN;
return xdr_encode_opaque(p, string, len);
}
/*
* "mon_name" specifies the host to be monitored.
*
* Linux uses a text version of the IP address of the remote
* host as the host identifier (the "mon_name" argument).
*
* Linux statd always looks up the canonical hostname first for
* whatever remote hostname it receives, so this works alright.
*/
static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp)
{
char buffer[XDR_ADDRBUF_LEN + 1];
char *name = argp->mon_name;
if (!nsm_use_hostnames) {
snprintf(buffer, XDR_ADDRBUF_LEN,
NIPQUAD_FMT, NIPQUAD(argp->addr));
name = buffer;
}
return xdr_encode_nsm_string(p, name);
}
/*
* The "my_id" argument specifies the hostname and RPC procedure
* to be called when the status manager receives notification
* (via the SM_NOTIFY call) that the state of host "mon_name"
* has changed.
*/
static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp)
{
p = xdr_encode_nsm_string(p, utsname()->nodename);
if (!p)
return ERR_PTR(-EIO);
*p++ = htonl(argp->prog);
*p++ = htonl(argp->vers);
*p++ = htonl(argp->proc);
return p;
}
/*
* The "mon_id" argument specifies the non-private arguments
* of an SM_MON or SM_UNMON call.
*/
static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp)
{
p = xdr_encode_mon_name(p, argp);
if (!p)
return ERR_PTR(-EIO);
return xdr_encode_my_id(p, argp);
}
/*
* The "priv" argument may contain private information required
* by the SM_MON call. This information will be supplied in the
* SM_NOTIFY call.
*
* Linux provides the raw IP address of the monitored host,
* left in network byte order.
*/
static __be32 *xdr_encode_priv(__be32 *p, struct nsm_args *argp)
{
*p++ = argp->addr;
*p++ = 0;
*p++ = 0;
*p++ = 0;
return p;
}
static int
xdr_encode_mon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
{
p = xdr_encode_mon_id(p, argp);
if (IS_ERR(p))
return PTR_ERR(p);
p = xdr_encode_priv(p, argp);
if (IS_ERR(p))
return PTR_ERR(p);
rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
return 0;
}
static int
xdr_encode_unmon(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
{
p = xdr_encode_mon_id(p, argp);
if (IS_ERR(p))
return PTR_ERR(p);
rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
return 0;
}
static int
xdr_decode_stat_res(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
{
resp->status = ntohl(*p++);
resp->state = ntohl(*p++);
dprintk("nsm: xdr_decode_stat_res status %d state %d\n",
resp->status, resp->state);
return 0;
}
static int
xdr_decode_stat(struct rpc_rqst *rqstp, __be32 *p, struct nsm_res *resp)
{
resp->state = ntohl(*p++);
return 0;
}
#define SM_my_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_my_id_sz (SM_my_name_sz+3)
#define SM_mon_name_sz (1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_mon_id_sz (SM_mon_name_sz+SM_my_id_sz)
#define SM_priv_sz (XDR_QUADLEN(SM_PRIV_SIZE))
#define SM_mon_sz (SM_mon_id_sz+SM_priv_sz)
#define SM_monres_sz 2
#define SM_unmonres_sz 1
static struct rpc_procinfo nsm_procedures[] = {
[SM_MON] = {
.p_proc = SM_MON,
.p_encode = (kxdrproc_t) xdr_encode_mon,
.p_decode = (kxdrproc_t) xdr_decode_stat_res,
.p_arglen = SM_mon_sz,
.p_replen = SM_monres_sz,
.p_statidx = SM_MON,
.p_name = "MONITOR",
},
[SM_UNMON] = {
.p_proc = SM_UNMON,
.p_encode = (kxdrproc_t) xdr_encode_unmon,
.p_decode = (kxdrproc_t) xdr_decode_stat,
.p_arglen = SM_mon_id_sz,
.p_replen = SM_unmonres_sz,
.p_statidx = SM_UNMON,
.p_name = "UNMONITOR",
},
};
static struct rpc_version nsm_version1 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nsm_procedures),
.procs = nsm_procedures
};
static struct rpc_version * nsm_version[] = {
[1] = &nsm_version1,
};
static struct rpc_stat nsm_stats;
static struct rpc_program nsm_program = {
.name = "statd",
.number = SM_PROGRAM,
.nrvers = ARRAY_SIZE(nsm_version),
.version = nsm_version,
.stats = &nsm_stats
};