path: root/fs/nfsd/export.c

#define MSNFS	/* HACK HACK */
/*
 * linux/fs/nfsd/export.c
 *
 * NFS exporting and validation.
 *
 * We maintain a list of clients, each of which has a list of
 * exports. To export an fs to a given client, you first have
 * to create the client entry with NFSCTL_ADDCLIENT, which
 * creates a client control block and adds it to the hash
 * table. Then, you call NFSCTL_EXPORT for each fs.
 *
 *
 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
 */

#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/in.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/rwsem.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/hash.h>
#include <linux/module.h>

#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/nfsfh.h>
#include <linux/nfsd/syscall.h>
#include <linux/lockd/bind.h>

#define NFSDDBG_FACILITY	NFSDDBG_EXPORT
#define NFSD_PARANOIA 1

typedef struct auth_domain	svc_client;
typedef struct svc_export	svc_export;

static void		exp_do_unexport(svc_export *unexp);
static int		exp_verify_string(char *cp, int max);

/*
 * We have two caches.
 * One maps client+vfsmnt+dentry to export options - the export map
 * The other maps client+filehandle-fragment to export options. - the expkey map
 *
 * The export options are actually stored in the first map, and the
 * second map contains a reference to the entry in the first map.
 */

#define	EXPKEY_HASHBITS		8
#define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
#define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
static struct cache_head *expkey_table[EXPKEY_HASHMAX];

static inline int svc_expkey_hash(struct svc_expkey *item)
{
	int hash = item->ek_fsidtype;
	char * cp = (char*)item->ek_fsid;
	int len = key_len(item->ek_fsidtype);

	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
	return hash & EXPKEY_HASHMASK;
}

void expkey_put(struct cache_head *item, struct cache_detail *cd)
{
	if (cache_put(item, cd)) {
		struct svc_expkey *key = container_of(item, struct svc_expkey, h);
		if (test_bit(CACHE_VALID, &item->flags) &&
		    !test_bit(CACHE_NEGATIVE, &item->flags)) {
			dput(key->ek_dentry);
			mntput(key->ek_mnt);
		}
		auth_domain_put(key->ek_client);
		kfree(key);
	}
}

static void expkey_request(struct cache_detail *cd,
			   struct cache_head *h,
			   char **bpp, int *blen)
{
	/* client fsidtype \xfsid */
	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
	char type[5];

	qword_add(bpp, blen, ek->ek_client->name);
	snprintf(type, 5, "%d", ek->ek_fsidtype);
	qword_add(bpp, blen, type);
	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
	(*bpp)[-1] = '\n';
}

static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *, int);
static int expkey_parse(struct cache_detail