1 files changed, 908 insertions, 0 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
new file mode 100644
index 000000000..af7f28fb8
--- /dev/null
+++ b/net/sunrpc/svcauth_unix.c
@@ -0,0 +1,908 @@
+#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/sunrpc/addr.h>
+#include <linux/err.h>
+#include <linux/seq_file.h>
+#include <linux/hash.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/ipv6.h>
+#include <linux/kernel.h>
+#include <linux/user_namespace.h>
+#define RPCDBG_FACILITY	RPCDBG_AUTH
+
+
+#include "netns.h"
+
+/*
+ * 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;
+	/* other stuff later */
+};
+
+extern struct auth_ops svcauth_null;
+extern struct auth_ops svcauth_unix;
+
+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);
+}
+
+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)
+				svcauth_unix_domain_release(&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;
+		rv = auth_domain_lookup(name, &new->h);
+	}
+}
+EXPORT_SYMBOL_GPL(unix_domain_find);
+
+
+/**************************************************
+ * cache for IP address to unix_domain
+ * as needed by AUTH_UNIX
+ */
+#define	IP_HASHBITS	8
+#define	IP_HASHMAX	(1<<IP_HASHBITS)
+
+struct ip_map {
+	struct cache_head	h;
+	char			m_class[8]; /* e.g. "nfsd" */
+	struct in6_addr		m_addr;
+	struct unix_domain	*m_client;
+};
+
+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);
+}
+
+static inline int hash_ip6(const struct in6_addr *ip)
+{
+	return hash_32(ipv6_addr_hash(ip), IP_HASHBITS);
+}
+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);
+	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;
+}
+static struct cache_head *ip_map_alloc(void)
+{
+	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
+	if (i)
+		return &i->h;
+	else
+		return NULL;
+}
+
+static void ip_map_request(struct cache_detail *cd,
+				  struct cache_head *h,
+				  char **bpp, int *blen)
+{
+	char text_addr[40];
+	struct ip_map *im = container_of(h, struct ip_map, h);
+
+	if (ipv6_addr_v4mapped(&(im->m_addr))) {
+		snprintf(text_addr, 20, "%pI4", &im->m_addr.s6_addr32[3]);
+	} else {
+		snprintf(text_addr, 40, "%pI6", &im->m_addr);
+	}
+	qword_add(bpp, blen, im->m_class);
+	qword_add(bpp, blen, text_addr);
+	(*bpp)[-1] = '\n';
+}
+
+static struct ip_map *__ip_map_lookup(struct cache_detail *cd, char *class, struct in6_addr *addr);
+static int __ip_map_update(struct cache_detail *cd, struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
+
+static int ip_map_parse(struct cache_detail *cd,
+			  char *mesg, int mlen)
+{
+	/* class ipaddress [domainname] */
+	/* should be safe just to use the start of the input buffer
+	 * for scratch: */
+	char *buf = mesg;
+	int len;
+	char class[8];
+	union {
+		struct sockaddr		sa;
+		struct sockaddr_in	s4;
+		struct sockaddr_in6	s6;
+	} address;
+	struct sockaddr_in6 sin6;
+	int err;
+
+	struct ip_map *ipmp;
+	struct auth_domain *dom;
+	time_t expiry;
+
+	if (mesg[mlen-1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	/* class */
+	len = qword_get(&mesg, class, sizeof(class));
+	if (len <= 0) return -EINVAL;
+
+	/* ip address */
+	len = qword_get(&mesg, buf, mlen);
+	if (len <= 0) return -EINVAL;
+
+	if (rpc_pton(cd->net, buf, len, &address.sa, sizeof(address)) == 0)
+		return -EINVAL;
+	switch (address.sa.sa_family) {
+	case AF_INET:
+		/* Form a mapped IPv4 address in sin6 */
+		sin6.sin6_family = AF_INET6;
+		ipv6_addr_set_v4mapped(address.s4.sin_addr.s_addr,
+				&sin6.sin6_addr);
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		memcpy(&sin6, &address.s6, sizeof(sin6));
+		break;
+#endif
+	default:
+		return -EINVAL;
+	}
+
+	expiry = get_expiry(&mesg);
+	if (expiry ==0)
+		return -EINVAL;
+
+	/* domainname, or empty for NEGATIVE */
+	len = qword_get(&mesg, buf, mlen);
+	if (len < 0) return -EINVAL;
+
+	if (len) {
+		dom = unix_domain_find(buf);
+		if (dom == NULL)
+			return -ENOENT;
+	} else
+		dom = NULL;
+
+	/* IPv6 scope IDs are ignored for now */
+	ipmp = __ip_map_lookup(cd, class, &sin6.sin6_addr);
+	if (ipmp) {
+		err = __ip_map_update(cd, ipmp,
+			     container_of(dom, struct unix_domain, h),
+			     expiry);
+	} else
+		err = -ENOMEM;
+
+	if (dom)
+		auth_domain_put(dom);
+
+	cache_flush();
+	return err;
+}
+
+static int ip_map_show(struct seq_file *m,
+		       struct cache_detail *cd,
+		       struct cache_head *h)
+{
+	struct ip_map *im;
+	struct in6_addr addr;
+	char *dom = "-no-domain-";
+
+	if (h == NULL) {
+		seq_puts(m, "#class IP domain\n");
+		return 0;
+	}
+	im = container_of(h, struct ip_map, h);
+	/* class addr domain */
+	addr = im->m_addr;
+
+	if (test_bit(CACHE_VALID, &h->flags) &&
+	    !test_bit(CACHE_NEGATIVE, &h->flags))
+		dom = im->m_client->h.name;
+
+	if (ipv6_addr_v4mapped(&addr)) {
+		seq_printf(m, "%s %pI4 %s\n",
+			im->m_class, &addr.s6_addr32[3], dom);
+	} else {
+		seq_printf(m, "%s %pI6 %s\n", im->m_class, &addr, dom);
+	}
+	return 0;
+}
+
+
+static struct ip_map *__ip_map_lookup(struct cache_detail *cd, char *class,
+		struct in6_addr *addr)
+{
+	struct ip_map ip;
+	struct cache_head *ch;
+
+	strcpy(ip.m_class, class);
+	ip.m_addr = *addr;
+	ch = sunrpc_cache_lookup(cd, &ip.h,
+				 hash_str(class, IP_HASHBITS) ^
+				 hash_ip6(addr));
+
+	if (ch)
+		return container_of(ch, struct ip_map, h);
+	else
+		return NULL;
+}
+
+static inline struct ip_map *ip_map_lookup(struct net *net, char *class,
+		struct in6_addr *addr)
+{
+	struct sunrpc_net *sn;
+
+	sn = net_generic(net, sunrpc_net_id);
+	return __ip_map_lookup(sn->ip_map_cache, class, addr);
+}
+
+static int __ip_map_update(struct cache_detail *cd, struct ip_map *ipm,
+		struct unix_domain *udom, time_t expiry)
+{
+	struct ip_map ip;
+	struct cache_head *ch;
+
+	ip.m_client = udom;
+	ip.h.flags = 0;
+	if (!udom)
+		set_bit(CACHE_NEGATIVE, &ip.h.flags);
+	ip.h.expiry_time = expiry;
+	ch = sunrpc_cache_update(cd, &ip.h, &ipm->h,
+				 hash_str(ipm->m_class, IP_HASHBITS) ^
+				 hash_ip6(&ipm->m_addr));
+	if (!ch)
+		return -ENOMEM;
+	cache_put(ch, cd);
+	return 0;
+}
+
+static inline int ip_map_update(struct net *net, struct ip_map *ipm,
+		struct unix_domain *udom, time_t expiry)
+{
+	struct sunrpc_net *sn;
+
+	sn = net_generic(net, sunrpc_net_id);
+	return __ip_map_update(sn->ip_map_cache, ipm, udom, expiry);
+}
+
+void svcauth_unix_purge(struct net *net)
+{
+	struct sunrpc_net *sn;
+
+	sn = net_generic(net, sunrpc_net_id);
+	cache_purge(sn->ip_map_cache);
+}
+EXPORT_SYMBOL_GPL(svcauth_unix_purge);
+
+static inline struct ip_map *
+ip_map_cached_get(struct svc_xprt *xprt)
+{
+	struct ip_map *ipm = NULL;
+	struct sunrpc_net *sn;
+
+	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
+		spin_lock(&xprt->xpt_lock);
+		ipm = xprt->xpt_auth_cache;
+		if (ipm != NULL) {
+			sn = net_generic(xprt->xpt_net, sunrpc_net_id);
+			if (cache_is_expired(sn->ip_map_cache, &ipm->h)) {
+				/*
+				 * The entry has been invalidated since it was
+				 * remembered, e.g. by a second mount from the
+				 * same IP address.
+				 */
+				xprt->xpt_auth_cache = NULL;
+				spin_unlock(&xprt->xpt_lock);
+				cache_put(&ipm->h, sn->ip_map_cache);
+				return NULL;
+			}
+			cache_get(&ipm->h);
+		}
+		spin_unlock(&xprt->xpt_lock);
+	}
+	return ipm;
+}
+
+static inline void
+ip_map_cached_put(struct svc_xprt *xprt, struct ip_map *ipm)
+{
+	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
+		spin_lock(&xprt->xpt_lock);
+		if (xprt->xpt_auth_cache == NULL) {
+			/* newly cached, keep the reference */
+			xprt->xpt_auth_cache = ipm;
+			ipm = NULL;
+		}
+		spin_unlock(&xprt->xpt_lock);
+	}
+	if (ipm) {
+		struct sunrpc_net *sn;
+
+		sn = net_generic(xprt->xpt_net, sunrpc_net_id);
+		cache_put(&ipm->h, sn->ip_map_cache);
+	}
+}
+
+void
+svcauth_unix_info_release(struct svc_xprt *xpt)
+{
+	struct ip_map *ipm;
+
+	ipm = xpt->xpt_auth_cache;
+	if (ipm != NULL) {
+		struct sunrpc_net *sn;
+
+		sn = net_generic(xpt->xpt_net, sunrpc_net_id);
+		cache_put(&ipm->h, sn->ip_map_cache);
+	}
+}
+
+/****************************************************************************
+ * auth.unix.gid cache
+ * simple cache to map a UID to a list of GIDs
+ * because AUTH_UNIX aka AUTH_SYS has a max of UNX_NGROUPS
+ */
+#define	GID_HASHBITS	8
+#define	GID_HASHMAX	(1<<GID_HASHBITS)
+
+struct unix_gid {
+	struct cache_head	h;
+	kuid_t			uid;
+	struct group_info	*gi;
+};
+
+static int unix_gid_hash(kuid_t uid)
+{
+	return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS);
+}
+
+static void unix_gid_put(struct kref *kref)
+{
+	struct cache_head *item = container_of(kref, struct cache_head, ref);
+	struct unix_gid *ug = container_of(item, struct unix_gid, h);
+	if (test_bit(CACHE_VALID, &item->flags) &&
+	    !test_bit(CACHE_NEGATIVE, &item->flags))
+		put_group_info(ug->gi);
+	kfree(ug);
+}
+
+static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
+{
+	struct unix_gid *orig = container_of(corig, struct unix_gid, h);
+	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
+	return uid_eq(orig->uid, new->uid);
+}
+static void unix_gid_init(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
+	struct unix_gid *item = container_of(citem, struct unix_gid, h);
+	new->uid = item->uid;
+}
+static void unix_gid_update(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
+	struct unix_gid *item = container_of(citem, struct unix_gid, h);
+
+	get_group_info(item->gi);
+	new->gi = item->gi;
+}
+static struct cache_head *unix_gid_alloc(void)
+{
+	struct unix_gid *g = kmalloc(sizeof(*g), GFP_KERNEL);
+	if (g)
+		return &g->h;
+	else
+		return NULL;
+}
+
+static void unix_gid_request(struct cache_detail *cd,
+			     struct cache_head *h,
+			     char **bpp, int *blen)
+{
+	char tuid[20];
+	struct unix_gid *ug = container_of(h, struct unix_gid, h);
+
+	snprintf(tuid, 20, "%u", from_kuid(&init_user_ns, ug->uid));
+	qword_add(bpp, blen, tuid);
+	(*bpp)[-1] = '\n';
+}
+
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid);
+
+static int unix_gid_parse(struct cache_detail *cd,
+			char *mesg, int mlen)
+{
+	/* uid expiry Ngid gid0 gid1 ... gidN-1 */
+	int id;
+	kuid_t uid;
+	int gids;
+	int rv;
+	int i;
+	int err;
+	time_t expiry;
+	struct unix_gid ug, *ugp;
+
+	if (mesg[mlen - 1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	rv = get_int(&mesg, &id);
+	if (rv)
+		return -EINVAL;
+	uid = make_kuid(&init_user_ns, id);
+	ug.uid = uid;
+
+	expiry = get_expiry(&mesg);
+	if (expiry == 0)
+		return -EINVAL;
+
+	rv = get_int(&mesg, &gids);
+	if (rv || gids < 0 || gids > 8192)
+		return -EINVAL;
+
+	ug.gi = groups_alloc(gids);
+	if (!ug.gi)
+		return -ENOMEM;
+
+	for (i = 0 ; i < gids ; i++) {
+		int gid;
+		kgid_t kgid;
+		rv = get_int(&mesg, &gid);
+		err = -EINVAL;
+		if (rv)
+			goto out;
+		kgid = make_kgid(&init_user_ns, gid);
+		if (!gid_valid(kgid))
+			goto out;
+		ug.gi->gid[i] = kgid;
+	}
+
+	groups_sort(ug.gi);
+	ugp = unix_gid_lookup(cd, uid);
+	if (ugp) {
+		struct cache_head *ch;
+		ug.h.flags = 0;
+		ug.h.expiry_time = expiry;
+		ch = sunrpc_cache_update(cd,
+					 &ug.h, &ugp->h,
+					 unix_gid_hash(uid));
+		if (!ch)
+			err = -ENOMEM;
+		else {
+			err = 0;
+			cache_put(ch, cd);
+		}
+	} else
+		err = -ENOMEM;
+ out:
+	if (ug.gi)
+		put_group_info(ug.gi);
+	return err;
+}
+
+static int unix_gid_show(struct seq_file *m,
+			 struct cache_detail *cd,
+			 struct cache_head *h)
+{
+	struct user_namespace *user_ns = &init_user_ns;
+	struct unix_gid *ug;
+	int i;
+	int glen;
+
+	if (h == NULL) {
+		seq_puts(m, "#uid cnt: gids...\n");
+		return 0;
+	}
+	ug = container_of(h, struct unix_gid, h);
+	if (test_bit(CACHE_VALID, &h->flags) &&
+	    !test_bit(CACHE_NEGATIVE, &h->flags))
+		glen = ug->gi->ngroups;
+	else
+		glen = 0;
+
+	seq_printf(m, "%u %d:", from_kuid_munged(user_ns, ug->uid), glen);
+	for (i = 0; i < glen; i++)
+		seq_printf(m, " %d", from_kgid_munged(user_ns, ug->gi->gid[i]));
+	seq_printf(m, "\n");
+	return 0;
+}
+
+static const struct cache_detail unix_gid_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= GID_HASHMAX,
+	.name		= "auth.unix.gid",
+	.cache_put	= unix_gid_put,
+	.cache_request	= unix_gid_request,
+	.cache_parse	= unix_gid_parse,
+	.cache_show	= unix_gid_show,
+	.match		= unix_gid_match,
+	.init		= unix_gid_init,
+	.update		= unix_gid_update,
+	.alloc		= unix_gid_alloc,
+};
+
+int unix_gid_cache_create(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd;
+	int err;
+
+	cd = cache_create_net(&unix_gid_cache_template, net);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	err = cache_register_net(cd, net);
+	if (err) {
+		cache_destroy_net(cd, net);
+		return err;
+	}
+	sn->unix_gid_cache = cd;
+	return 0;
+}
+
+void unix_gid_cache_destroy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd = sn->unix_gid_cache;
+
+	sn->unix_gid_cache = NULL;
+	cache_purge(cd);
+	cache_unregister_net(cd, net);
+	cache_destroy_net(cd, net);
+}
+
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid)
+{
+	struct unix_gid ug;
+	struct cache_head *ch;
+
+	ug.uid = uid;
+	ch = sunrpc_cache_lookup(cd, &ug.h, unix_gid_hash(uid));
+	if (ch)
+		return container_of(ch, struct unix_gid, h);
+	else
+		return NULL;
+}
+
+static struct group_info *unix_gid_find(kuid_t uid, struct svc_rqst *rqstp)
+{
+	struct unix_gid *ug;
+	struct group_info *gi;
+	int ret;
+	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net,
+					    sunrpc_net_id);
+
+	ug = unix_gid_lookup(sn->unix_gid_cache, uid);
+	if (!ug)
+		return ERR_PTR(-EAGAIN);
+	ret = cache_check(sn->unix_gid_cache, &ug->h, &rqstp->rq_chandle);
+	switch (ret) {
+	case -ENOENT:
+		return ERR_PTR(-ENOENT);
+	case -ETIMEDOUT:
+		return ERR_PTR(-ESHUTDOWN);
+	case 0:
+		gi = get_group_info(ug->gi);
+		cache_put(&ug->h, sn->unix_gid_cache);
+		return gi;
+	default:
+		return ERR_PTR(-EAGAIN);
+	}
+}
+
+int
+svcauth_unix_set_client(struct svc_rqst *rqstp)
+{
+	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin6, sin6_storage;
+	struct ip_map *ipm;
+	struct group_info *gi;
+	struct svc_cred *cred = &rqstp->rq_cred;
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+	struct net *net = xprt->xpt_net;
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+
+	switch (rqstp->rq_addr.ss_family) {
+	case AF_INET:
+		sin = svc_addr_in(rqstp);
+		sin6 = &sin6_storage;
+		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &sin6->sin6_addr);
+		break;
+	case AF_INET6:
+		sin6 = svc_addr_in6(rqstp);
+		break;
+	default:
+		BUG();
+	}
+
+	rqstp->rq_client = NULL;
+	if (rqstp->rq_proc == 0)
+		return SVC_OK;
+
+	ipm = ip_map_cached_get(xprt);
+	if (ipm == NULL)
+		ipm = __ip_map_lookup(sn->ip_map_cache, rqstp->rq_server->sv_program->pg_class,
+				    &sin6->sin6_addr);
+
+	if (ipm == NULL)
+		return SVC_DENIED;
+
+	switch (cache_check(sn->ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
+		default:
+			BUG();
+		case -ETIMEDOUT:
+			return SVC_CLOSE;
+		case -EAGAIN:
+			return SVC_DROP;
+		case -ENOENT:
+			return SVC_DENIED;
+		case 0:
+			rqstp->rq_client = &ipm->m_client->h;
+			kref_get(&rqstp->rq_client->ref);
+			ip_map_cached_put(xprt, ipm);
+			break;
+	}
+
+	gi = unix_gid_find(cred->cr_uid, rqstp);
+	switch (PTR_ERR(gi)) {
+	case -EAGAIN:
+		return SVC_DROP;
+	case -ESHUTDOWN:
+		return SVC_CLOSE;
+	case -ENOENT:
+		break;
+	default:
+		put_group_info(cred->cr_group_info);
+		cred->cr_group_info = gi;
+	}
+	return SVC_OK;
+}
+
+EXPORT_SYMBOL_GPL(svcauth_unix_set_client);
+
+static int
+svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
+{
+	struct kvec	*argv = &rqstp->rq_arg.head[0];
+	struct kvec	*resv = &rqstp->rq_res.head[0];
+	struct svc_cred	*cred = &rqstp->rq_cred;
+
+	if (argv->iov_len < 3*4)
+		return SVC_GARBAGE;
+
+	if (svc_getu32(argv) != 0) {
+		dprintk("svc: bad null cred\n");
+		*authp = rpc_autherr_badcred;
+		return SVC_DENIED;
+	}
+	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
+		dprintk("svc: bad null verf\n");
+		*authp = rpc_autherr_badverf;
+		return SVC_DENIED;
+	}
+
+	/* Signal that mapping to nobody uid/gid is required */
+	cred->cr_uid = INVALID_UID;
+	cred->cr_gid = INVALID_GID;
+	cred->cr_group_info = groups_alloc(0);
+	if (cred->cr_group_info == NULL)
+		return SVC_CLOSE; /* kmalloc failure - client must retry */
+
+	/* Put NULL verifier */
+	svc_putnl(resv, RPC_AUTH_NULL);
+	svc_putnl(resv, 0);
+
+	rqstp->rq_cred.cr_flavor = RPC_AUTH_NULL;
+	return SVC_OK;
+}
+
+static int
+svcauth_null_release(struct svc_rqst *rqstp)
+{
+	if (rqstp->rq_client)
+		auth_domain_put(rqstp->rq_client);
+	rqstp->rq_client = NULL;
+	if (rqstp->rq_cred.cr_group_info)
+		put_group_info(rqstp->rq_cred.cr_group_info);
+	rqstp->rq_cred.cr_group_info = NULL;
+
+	return 0; /* don't drop */
+}
+
+
+struct auth_ops svcauth_null = {
+	.name		= "null",
+	.owner		= THIS_MODULE,
+	.flavour	= RPC_AUTH_NULL,
+	.accept 	= svcauth_null_accept,
+	.release	= svcauth_null_release,
+	.set_client	= svcauth_unix_set_client,
+};
+
+
+static int
+svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
+{
+	struct kvec	*argv = &rqstp->rq_arg.head[0];
+	struct kvec	*resv = &rqstp->rq_res.head[0];
+	struct svc_cred	*cred = &rqstp->rq_cred;
+	u32		slen, i;
+	int		len   = argv->iov_len;
+
+	if ((len -= 3*4) < 0)
+		return SVC_GARBAGE;
+
+	svc_getu32(argv);			/* length */
+	svc_getu32(argv);			/* time stamp */
+	slen = XDR_QUADLEN(svc_getnl(argv));	/* machname length */
+	if (slen > 64 || (len -= (slen + 3)*4) < 0)
+		goto badcred;
+	argv->iov_base = (void*)((__be32*)argv->iov_base + slen);	/* skip machname */
+	argv->iov_len -= slen*4;
+	/*
+	 * Note: we skip uid_valid()/gid_valid() checks here for
+	 * backwards compatibility with clients that use -1 id's.
+	 * Instead, -1 uid or gid is later mapped to the
+	 * (export-specific) anonymous id by nfsd_setuser.
+	 * Supplementary gid's will be left alone.
+	 */
+	cred->cr_uid = make_kuid(&init_user_ns, svc_getnl(argv)); /* uid */
+	cred->cr_gid = make_kgid(&init_user_ns, svc_getnl(argv)); /* gid */
+	slen = svc_getnl(argv);			/* gids length */
+	if (slen > UNX_NGROUPS || (len -= (slen + 2)*4) < 0)
+		goto badcred;
+	cred->cr_group_info = groups_alloc(slen);
+	if (cred->cr_group_info == NULL)
+		return SVC_CLOSE;
+	for (i = 0; i < slen; i++) {
+		kgid_t kgid = make_kgid(&init_user_ns, svc_getnl(argv));
+		cred->cr_group_info->gid[i] = kgid;
+	}
+	groups_sort(cred->cr_group_info);
+	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
+		*authp = rpc_autherr_badverf;
+		return SVC_DENIED;
+	}
+
+	/* Put NULL verifier */
+	svc_putnl(resv, RPC_AUTH_NULL);
+	svc_putnl(resv, 0);
+
+	rqstp->rq_cred.cr_flavor = RPC_AUTH_UNIX;
+	return SVC_OK;
+
+badcred:
+	*authp = rpc_autherr_badcred;
+	return SVC_DENIED;
+}
+
+static int
+svcauth_unix_release(struct svc_rqst *rqstp)
+{
+	/* Verifier (such as it is) is already in place.
+	 */
+	if (rqstp->rq_client)
+		auth_domain_put(rqstp->rq_client);
+	rqstp->rq_client = NULL;
+	if (rqstp->rq_cred.cr_group_info)
+		put_group_info(rqstp->rq_cred.cr_group_info);
+	rqstp->rq_cred.cr_group_info = NULL;
+
+	return 0;
+}
+
+
+struct auth_ops svcauth_unix = {
+	.name		= "unix",
+	.owner		= THIS_MODULE,
+	.flavour	= RPC_AUTH_UNIX,
+	.accept 	= svcauth_unix_accept,
+	.release	= svcauth_unix_release,
+	.domain_release	= svcauth_unix_domain_release,
+	.set_client	= svcauth_unix_set_client,
+};
+
+static const struct cache_detail ip_map_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= IP_HASHMAX,
+	.name		= "auth.unix.ip",
+	.cache_put	= ip_map_put,
+	.cache_request	= ip_map_request,
+	.cache_parse	= ip_map_parse,
+	.cache_show	= ip_map_show,
+	.match		= ip_map_match,
+	.init		= ip_map_init,
+	.update		= update,
+	.alloc		= ip_map_alloc,
+};
+
+int ip_map_cache_create(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd;
+	int err;
+
+	cd = cache_create_net(&ip_map_cache_template, net);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	err = cache_register_net(cd, net);
+	if (err) {
+		cache_destroy_net(cd, net);
+		return err;
+	}
+	sn->ip_map_cache = cd;
+	return 0;
+}
+
+void ip_map_cache_destroy(struct net *net)
+{
+	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+	struct cache_detail *cd = sn->ip_map_cache;
+
+	sn->ip_map_cache = NULL;
+	cache_purge(cd);
+	cache_unregister_net(cd, net);
+	cache_destroy_net(cd, net);
+}