path: root/net/sunrpc/svcauth_unix.c

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/sunrpc/gss_api.h>
#include <linux/err.h>
#include <linux/seq_file.h>
#include <linux/hash.h>
#include <linux/string.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <linux/kernel.h>
#define RPCDBG_FACILITY	RPCDBG_AUTH


/*
 * AUTHUNIX and AUTHNULL credentials are both handled here.
 * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
 * are always nobody (-2).  i.e. we do the same IP address checks for
 * AUTHNULL as for AUTHUNIX, and that is done here.
 */


struct unix_domain {
	struct auth_domain	h;
	int	addr_changes;
	/* other stuff later */
};

extern struct auth_ops svcauth_unix;

struct auth_domain *unix_domain_find(char *name)
{
	struct auth_domain *rv;
	struct unix_domain *new = NULL;

	rv = auth_domain_lookup(name, NULL);
	while(1) {
		if (rv) {
			if (new && rv != &new->h)
				auth_domain_put(&new->h);

			if (rv->flavour != &svcauth_unix) {
				auth_domain_put(rv);
				return NULL;
			}
			return rv;
		}

		new = kmalloc(sizeof(*new), GFP_KERNEL);
		if (new == NULL)
			return NULL;
		kref_init(&new->h.ref);
		new->h.name = kstrdup(name, GFP_KERNEL);
		if (new->h.name == NULL) {
			kfree(new);
			return NULL;
		}
		new->h.flavour = &svcauth_unix;
		new->addr_changes = 0;
		rv = auth_domain_lookup(name, &new->h);
	}
}
EXPORT_SYMBOL(unix_domain_find);

static void svcauth_unix_domain_release(struct auth_domain *dom)
{
	struct unix_domain *ud = container_of(dom, struct unix_domain, h);

	kfree(dom->name);
	kfree(ud);
}


/**************************************************
 * cache for IP address to unix_domain
 * as needed by AUTH_UNIX
 */
#define	IP_HASHBITS	8
#define	IP_HASHMAX	(1<<IP_HASHBITS)
#define	IP_HASHMASK	(IP_HASHMAX-1)

struct ip_map {
	struct cache_head	h;
	char			m_class[8]; /* e.g. "nfsd" */
	struct in6_addr		m_addr;
	struct unix_domain	*m_client;
	int			m_add_change;
};
static struct cache_head	*ip_table[IP_HASHMAX];

static void ip_map_put(struct kref *kref)
{
	struct cache_head *item = container_of(kref, struct cache_head, ref);
	struct ip_map *im = container_of(item, struct ip_map,h);

	if (test_bit(CACHE_VALID, &item->flags) &&
	    !test_bit(CACHE_NEGATIVE, &item->flags))
		auth_domain_put(&im->m_client->h);
	kfree(im);
}

#if IP_HASHBITS == 8
/* hash_long on a 64 bit machine is currently REALLY BAD for
 * IP addresses in reverse-endian (i.e. on a little-endian machine).
 * So use a trivial but reliable hash instead
 */
static inline int hash_ip(__be32 ip)
{
	int hash = (__force u32)ip ^ ((__force u32)ip>>16);
	return (hash ^ (hash>>8)) & 0xff;
}
#endif
static inline int hash_ip6(struct in6_addr ip)
{
	return (hash_ip(ip.s6_addr32[0]) ^
		hash_ip(ip.s6_addr32[1]) ^
		hash_ip(ip.s6_addr32[2]) ^
		hash_ip(ip.s6_addr32[3]));
}
static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
{
	struct ip_map *orig = container_of(corig, struct ip_map, h);
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	return strcmp(orig->m_class, new->m_class) == 0
		&& ipv6_addr_equal(&orig->m_addr, &new->m_addr);
}
static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
{
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	struct ip_map *item = container_of(citem, struct ip_map, h);

	strcpy(new->m_class, item->m_class);
	ipv6_addr_copy(&new->m_addr, &item->m_addr);
}
static void update(struct cache_head *cnew, struct cache_head *citem)
{
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	struct ip_map *item = container_of(citem, struct ip_map, h);

	kref_get(&item->m_client->h.ref);
	new->m_client = item->m_client;
	new->m_add_change = item->m_add_change;
}
static struct cache_head *ip_map_alloc(void)
{
	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
	if (i)
		return &i->h;
	else
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