 3460f29a27
			
		
	
	
	3460f29a27
	
	
	
		
			
			We'd like to prevent local buffer overflows caused by malicious or broken servers. New xdr_stream style decoders can do that. For efficiency, we also want to be able to pass xdr_streams from call_encode() to all XDR encoding functions, rather than building an xdr_stream in every XDR encoding function in the kernel. Same idea as the NLM v3 XDR overhaul. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
		
			
				
	
	
		
			334 lines
		
	
	
	
		
			7.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			334 lines
		
	
	
	
		
			7.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * linux/fs/lockd/xdr4.c
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|  *
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|  * XDR support for lockd and the lock client.
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|  *
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|  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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|  * Copyright (C) 1999, Trond Myklebust <trond.myklebust@fys.uio.no>
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|  */
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| 
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| #include <linux/types.h>
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| #include <linux/sched.h>
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| #include <linux/nfs.h>
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| 
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| #include <linux/sunrpc/xdr.h>
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| #include <linux/sunrpc/clnt.h>
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| #include <linux/sunrpc/svc.h>
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| #include <linux/sunrpc/stats.h>
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| #include <linux/lockd/lockd.h>
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| 
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| #define NLMDBG_FACILITY		NLMDBG_XDR
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| 
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| static inline loff_t
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| s64_to_loff_t(__s64 offset)
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| {
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| 	return (loff_t)offset;
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| }
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| 
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| 
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| static inline s64
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| loff_t_to_s64(loff_t offset)
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| {
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| 	s64 res;
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| 	if (offset > NLM4_OFFSET_MAX)
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| 		res = NLM4_OFFSET_MAX;
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| 	else if (offset < -NLM4_OFFSET_MAX)
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| 		res = -NLM4_OFFSET_MAX;
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| 	else
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| 		res = offset;
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| 	return res;
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| }
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| 
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| /*
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|  * XDR functions for basic NLM types
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|  */
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| static __be32 *
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| nlm4_decode_cookie(__be32 *p, struct nlm_cookie *c)
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| {
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| 	unsigned int	len;
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| 
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| 	len = ntohl(*p++);
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| 	
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| 	if(len==0)
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| 	{
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| 		c->len=4;
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| 		memset(c->data, 0, 4);	/* hockeypux brain damage */
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| 	}
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| 	else if(len<=NLM_MAXCOOKIELEN)
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| 	{
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| 		c->len=len;
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| 		memcpy(c->data, p, len);
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| 		p+=XDR_QUADLEN(len);
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| 	}
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| 	else 
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| 	{
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| 		dprintk("lockd: bad cookie size %d (only cookies under "
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| 			"%d bytes are supported.)\n",
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| 				len, NLM_MAXCOOKIELEN);
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| 		return NULL;
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| 	}
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| 	return p;
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| }
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| 
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| static __be32 *
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| nlm4_encode_cookie(__be32 *p, struct nlm_cookie *c)
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| {
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| 	*p++ = htonl(c->len);
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| 	memcpy(p, c->data, c->len);
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| 	p+=XDR_QUADLEN(c->len);
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| 	return p;
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| }
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| 
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| static __be32 *
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| nlm4_decode_fh(__be32 *p, struct nfs_fh *f)
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| {
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| 	memset(f->data, 0, sizeof(f->data));
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| 	f->size = ntohl(*p++);
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| 	if (f->size > NFS_MAXFHSIZE) {
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| 		dprintk("lockd: bad fhandle size %d (should be <=%d)\n",
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| 			f->size, NFS_MAXFHSIZE);
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| 		return NULL;
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| 	}
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|       	memcpy(f->data, p, f->size);
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| 	return p + XDR_QUADLEN(f->size);
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| }
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| 
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| /*
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|  * Encode and decode owner handle
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|  */
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| static __be32 *
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| nlm4_decode_oh(__be32 *p, struct xdr_netobj *oh)
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| {
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| 	return xdr_decode_netobj(p, oh);
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| }
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| 
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| static __be32 *
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| nlm4_decode_lock(__be32 *p, struct nlm_lock *lock)
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| {
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| 	struct file_lock	*fl = &lock->fl;
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| 	__u64			len, start;
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| 	__s64			end;
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| 
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| 	if (!(p = xdr_decode_string_inplace(p, &lock->caller,
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| 					    &lock->len, NLM_MAXSTRLEN))
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| 	 || !(p = nlm4_decode_fh(p, &lock->fh))
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| 	 || !(p = nlm4_decode_oh(p, &lock->oh)))
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| 		return NULL;
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| 	lock->svid  = ntohl(*p++);
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| 
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| 	locks_init_lock(fl);
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| 	fl->fl_owner = current->files;
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| 	fl->fl_pid   = (pid_t)lock->svid;
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| 	fl->fl_flags = FL_POSIX;
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| 	fl->fl_type  = F_RDLCK;		/* as good as anything else */
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| 	p = xdr_decode_hyper(p, &start);
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| 	p = xdr_decode_hyper(p, &len);
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| 	end = start + len - 1;
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| 
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| 	fl->fl_start = s64_to_loff_t(start);
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| 
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| 	if (len == 0 || end < 0)
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| 		fl->fl_end = OFFSET_MAX;
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| 	else
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| 		fl->fl_end = s64_to_loff_t(end);
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| 	return p;
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| }
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| 
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| /*
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|  * Encode result of a TEST/TEST_MSG call
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|  */
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| static __be32 *
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| nlm4_encode_testres(__be32 *p, struct nlm_res *resp)
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| {
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| 	s64		start, len;
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| 
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| 	dprintk("xdr: before encode_testres (p %p resp %p)\n", p, resp);
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| 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
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| 		return NULL;
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| 	*p++ = resp->status;
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| 
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| 	if (resp->status == nlm_lck_denied) {
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| 		struct file_lock	*fl = &resp->lock.fl;
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| 
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| 		*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
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| 		*p++ = htonl(resp->lock.svid);
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| 
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| 		/* Encode owner handle. */
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| 		if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
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| 			return NULL;
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| 
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| 		start = loff_t_to_s64(fl->fl_start);
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| 		if (fl->fl_end == OFFSET_MAX)
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| 			len = 0;
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| 		else
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| 			len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
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| 		
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| 		p = xdr_encode_hyper(p, start);
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| 		p = xdr_encode_hyper(p, len);
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| 		dprintk("xdr: encode_testres (status %u pid %d type %d start %Ld end %Ld)\n",
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| 			resp->status, (int)resp->lock.svid, fl->fl_type,
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| 			(long long)fl->fl_start,  (long long)fl->fl_end);
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| 	}
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| 
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| 	dprintk("xdr: after encode_testres (p %p resp %p)\n", p, resp);
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| 	return p;
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| }
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| 
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| 
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| /*
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|  * First, the server side XDR functions
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|  */
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| int
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| nlm4svc_decode_testargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
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| {
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| 	u32	exclusive;
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| 
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| 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
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| 		return 0;
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| 
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| 	exclusive = ntohl(*p++);
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| 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
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| 		return 0;
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| 	if (exclusive)
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| 		argp->lock.fl.fl_type = F_WRLCK;
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| 
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_encode_testres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
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| {
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| 	if (!(p = nlm4_encode_testres(p, resp)))
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| 		return 0;
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| 	return xdr_ressize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
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| {
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| 	u32	exclusive;
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| 
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| 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
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| 		return 0;
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| 	argp->block  = ntohl(*p++);
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| 	exclusive    = ntohl(*p++);
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| 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
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| 		return 0;
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| 	if (exclusive)
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| 		argp->lock.fl.fl_type = F_WRLCK;
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| 	argp->reclaim = ntohl(*p++);
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| 	argp->state   = ntohl(*p++);
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| 	argp->monitor = 1;		/* monitor client by default */
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| 
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
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| {
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| 	u32	exclusive;
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| 
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| 	if (!(p = nlm4_decode_cookie(p, &argp->cookie)))
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| 		return 0;
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| 	argp->block = ntohl(*p++);
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| 	exclusive = ntohl(*p++);
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| 	if (!(p = nlm4_decode_lock(p, &argp->lock)))
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| 		return 0;
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| 	if (exclusive)
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| 		argp->lock.fl.fl_type = F_WRLCK;
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
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| {
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| 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
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| 	 || !(p = nlm4_decode_lock(p, &argp->lock)))
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| 		return 0;
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| 	argp->lock.fl.fl_type = F_UNLCK;
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
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| {
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| 	struct nlm_lock	*lock = &argp->lock;
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| 
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| 	memset(lock, 0, sizeof(*lock));
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| 	locks_init_lock(&lock->fl);
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| 	lock->svid = ~(u32) 0;
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| 	lock->fl.fl_pid = (pid_t)lock->svid;
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| 
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| 	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
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| 	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
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| 					    &lock->len, NLM_MAXSTRLEN))
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| 	 || !(p = nlm4_decode_fh(p, &lock->fh))
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| 	 || !(p = nlm4_decode_oh(p, &lock->oh)))
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| 		return 0;
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| 	argp->fsm_mode = ntohl(*p++);
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| 	argp->fsm_access = ntohl(*p++);
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_encode_shareres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
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| {
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| 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
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| 		return 0;
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| 	*p++ = resp->status;
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| 	*p++ = xdr_zero;		/* sequence argument */
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| 	return xdr_ressize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_encode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
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| {
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| 	if (!(p = nlm4_encode_cookie(p, &resp->cookie)))
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| 		return 0;
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| 	*p++ = resp->status;
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| 	return xdr_ressize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
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| {
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| 	struct nlm_lock	*lock = &argp->lock;
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| 
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| 	if (!(p = xdr_decode_string_inplace(p, &lock->caller,
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| 					    &lock->len, NLM_MAXSTRLEN)))
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| 		return 0;
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| 	argp->state = ntohl(*p++);
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
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| {
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| 	if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
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| 		return 0;
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| 	argp->state = ntohl(*p++);
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| 	memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
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| 	p += XDR_QUADLEN(SM_PRIV_SIZE);
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
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| {
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| 	if (!(p = nlm4_decode_cookie(p, &resp->cookie)))
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| 		return 0;
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| 	resp->status = *p++;
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
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| {
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| 	return xdr_argsize_check(rqstp, p);
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| }
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| 
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| int
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| nlm4svc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
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| {
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| 	return xdr_ressize_check(rqstp, p);
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| }
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