linux/fs/lockd/mon.c
Trond Myklebust 5ee0ed7d3a [PATCH] RPC: Make rpc_create_client() probe server for RPC program+version support
Ensure that we don't create an RPC client without checking that the server
 does indeed support the RPC program + version that we are trying to set up.

 This enables us to immediately return an error to "mount" if it turns out
 that the server is only supporting NFSv2, when we requested NFSv3 or NFSv4.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:04 -04:00

245 lines
5.1 KiB
C

/*
* 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/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>
#define NLMDBG_FACILITY NLMDBG_MONITOR
static struct rpc_clnt * nsm_create(void);
static struct rpc_program nsm_program;
/*
* Local NSM state
*/
u32 nsm_local_state;
/*
* Common procedure for SM_MON/SM_UNMON calls
*/
static int
nsm_mon_unmon(struct nlm_host *host, u32 proc, struct nsm_res *res)
{
struct rpc_clnt *clnt;
int status;
struct nsm_args args;
clnt = nsm_create();
if (IS_ERR(clnt)) {
status = PTR_ERR(clnt);
goto out;
}
args.addr = host->h_addr.sin_addr.s_addr;
args.proto= (host->h_proto<<1) | host->h_server;
args.prog = NLM_PROGRAM;
args.vers = host->h_version;
args.proc = NLMPROC_NSM_NOTIFY;
memset(res, 0, sizeof(*res));
status = rpc_call(clnt, proc, &args, res, 0);
if (status < 0)
printk(KERN_DEBUG "nsm_mon_unmon: rpc failed, status=%d\n",
status);
else
status = 0;
out:
return status;
}
/*
* Set up monitoring of a remote host
*/
int
nsm_monitor(struct nlm_host *host)
{
struct nsm_res res;
int status;
dprintk("lockd: nsm_monitor(%s)\n", host->h_name);
status = nsm_mon_unmon(host, SM_MON, &res);
if (status < 0 || res.status != 0)
printk(KERN_NOTICE "lockd: cannot monitor %s\n", host->h_name);
else
host->h_monitored = 1;
return status;
}
/*
* Cease to monitor remote host
*/
int
nsm_unmonitor(struct nlm_host *host)
{
struct nsm_res res;
int status;
dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name);
status = nsm_mon_unmon(host, SM_UNMON, &res);
if (status < 0)
printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", host->h_name);
else
host->h_monitored = 0;
return status;
}
/*
* Create NSM client for the local host
*/
static struct rpc_clnt *
nsm_create(void)
{
struct rpc_xprt *xprt;
struct rpc_clnt *clnt;
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
sin.sin_port = 0;
xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
if (IS_ERR(xprt))
return (struct rpc_clnt *)xprt;
xprt->resvport = 1; /* NSM requires a reserved port */
clnt = rpc_create_client(xprt, "localhost",
&nsm_program, SM_VERSION,
RPC_AUTH_NULL);
if (IS_ERR(clnt))
goto out_err;
clnt->cl_softrtry = 1;
clnt->cl_chatty = 1;
clnt->cl_oneshot = 1;
return clnt;
out_err:
return clnt;
}
/*
* XDR functions for NSM.
*/
static u32 *
xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
char buffer[20];
/*
* Use the dotted-quad IP address of the remote host as
* identifier. Linux statd always looks up the canonical
* hostname first for whatever remote hostname it receives,
* so this works alright.
*/
sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
if (!(p = xdr_encode_string(p, buffer))
|| !(p = xdr_encode_string(p, system_utsname.nodename)))
return ERR_PTR(-EIO);
*p++ = htonl(argp->prog);
*p++ = htonl(argp->vers);
*p++ = htonl(argp->proc);
return p;
}
static int
xdr_encode_mon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
p = xdr_encode_common(rqstp, p, argp);
if (IS_ERR(p))
return PTR_ERR(p);
*p++ = argp->addr;
*p++ = argp->vers;
*p++ = argp->proto;
*p++ = 0;
rqstp->rq_slen = xdr_adjust_iovec(rqstp->rq_svec, p);
return 0;
}
static int
xdr_encode_unmon(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
{
p = xdr_encode_common(rqstp, 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, u32 *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, u32 *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 (3+1+SM_my_name_sz)
#define SM_mon_id_sz (1+XDR_QUADLEN(20)+SM_my_id_sz)
#define SM_mon_sz (SM_mon_id_sz+4)
#define SM_monres_sz 2
#define SM_unmonres_sz 1
#ifndef MAX
# define MAX(a, b) (((a) > (b))? (a) : (b))
#endif
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_bufsiz = MAX(SM_mon_sz, SM_monres_sz) << 2,
},
[SM_UNMON] = {
.p_proc = SM_UNMON,
.p_encode = (kxdrproc_t) xdr_encode_unmon,
.p_decode = (kxdrproc_t) xdr_decode_stat,
.p_bufsiz = MAX(SM_mon_id_sz, SM_unmonres_sz) << 2,
},
};
static struct rpc_version nsm_version1 = {
.number = 1,
.nrprocs = sizeof(nsm_procedures)/sizeof(nsm_procedures[0]),
.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 = sizeof(nsm_version)/sizeof(nsm_version[0]),
.version = nsm_version,
.stats = &nsm_stats
};