--- /dev/null
+/*
+ * SELinux NetLabel Support
+ *
+ * This file provides the necessary glue to tie NetLabel into the SELinux
+ * subsystem.
+ *
+ * Author: Paul Moore <paul@paul-moore.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2007, 2008
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/gfp.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/sock.h>
+#include <net/netlabel.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+#include "objsec.h"
+#include "security.h"
+#include "netlabel.h"
+
+/**
+ * selinux_netlbl_sidlookup_cached - Cache a SID lookup
+ * @skb: the packet
+ * @secattr: the NetLabel security attributes
+ * @sid: the SID
+ *
+ * Description:
+ * Query the SELinux security server to lookup the correct SID for the given
+ * security attributes. If the query is successful, cache the result to speed
+ * up future lookups. Returns zero on success, negative values on failure.
+ *
+ */
+static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
+ struct netlbl_lsm_secattr *secattr,
+ u32 *sid)
+{
+ int rc;
+
+ rc = security_netlbl_secattr_to_sid(secattr, sid);
+ if (rc == 0 &&
+ (secattr->flags & NETLBL_SECATTR_CACHEABLE) &&
+ (secattr->flags & NETLBL_SECATTR_CACHE))
+ netlbl_cache_add(skb, secattr);
+
+ return rc;
+}
+
+/**
+ * selinux_netlbl_sock_genattr - Generate the NetLabel socket secattr
+ * @sk: the socket
+ *
+ * Description:
+ * Generate the NetLabel security attributes for a socket, making full use of
+ * the socket's attribute cache. Returns a pointer to the security attributes
+ * on success, NULL on failure.
+ *
+ */
+static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
+{
+ int rc;
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct netlbl_lsm_secattr *secattr;
+
+ if (sksec->nlbl_secattr != NULL)
+ return sksec->nlbl_secattr;
+
+ secattr = netlbl_secattr_alloc(GFP_ATOMIC);
+ if (secattr == NULL)
+ return NULL;
+ rc = security_netlbl_sid_to_secattr(sksec->sid, secattr);
+ if (rc != 0) {
+ netlbl_secattr_free(secattr);
+ return NULL;
+ }
+ sksec->nlbl_secattr = secattr;
+
+ return secattr;
+}
+
+/**
+ * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr
+ * @sk: the socket
+ * @sid: the SID
+ *
+ * Query the socket's cached secattr and if the SID matches the cached value
+ * return the cache, otherwise return NULL.
+ *
+ */
+static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
+ const struct sock *sk,
+ u32 sid)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
+
+ if (secattr == NULL)
+ return NULL;
+
+ if ((secattr->flags & NETLBL_SECATTR_SECID) &&
+ (secattr->attr.secid == sid))
+ return secattr;
+
+ return NULL;
+}
+
+/**
+ * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
+ *
+ * Description:
+ * Invalidate the NetLabel security attribute mapping cache.
+ *
+ */
+void selinux_netlbl_cache_invalidate(void)
+{
+ netlbl_cache_invalidate();
+}
+
+/**
+ * selinux_netlbl_err - Handle a NetLabel packet error
+ * @skb: the packet
+ * @error: the error code
+ * @gateway: true if host is acting as a gateway, false otherwise
+ *
+ * Description:
+ * When a packet is dropped due to a call to avc_has_perm() pass the error
+ * code to the NetLabel subsystem so any protocol specific processing can be
+ * done. This is safe to call even if you are unsure if NetLabel labeling is
+ * present on the packet, NetLabel is smart enough to only act when it should.
+ *
+ */
+void selinux_netlbl_err(struct sk_buff *skb, int error, int gateway)
+{
+ netlbl_skbuff_err(skb, error, gateway);
+}
+
+/**
+ * selinux_netlbl_sk_security_free - Free the NetLabel fields
+ * @sksec: the sk_security_struct
+ *
+ * Description:
+ * Free all of the memory in the NetLabel fields of a sk_security_struct.
+ *
+ */
+void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
+{
+ if (sksec->nlbl_secattr != NULL)
+ netlbl_secattr_free(sksec->nlbl_secattr);
+}
+
+/**
+ * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
+ * @sksec: the sk_security_struct
+ * @family: the socket family
+ *
+ * Description:
+ * Called when the NetLabel state of a sk_security_struct needs to be reset.
+ * The caller is responsible for all the NetLabel sk_security_struct locking.
+ *
+ */
+void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
+{
+ sksec->nlbl_state = NLBL_UNSET;
+}
+
+/**
+ * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
+ * @skb: the packet
+ * @family: protocol family
+ * @type: NetLabel labeling protocol type
+ * @sid: the SID
+ *
+ * Description:
+ * Call the NetLabel mechanism to get the security attributes of the given
+ * packet and use those attributes to determine the correct context/SID to
+ * assign to the packet. Returns zero on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
+ u16 family,
+ u32 *type,
+ u32 *sid)
+{
+ int rc;
+ struct netlbl_lsm_secattr secattr;
+
+ if (!netlbl_enabled()) {
+ *sid = SECSID_NULL;
+ return 0;
+ }
+
+ netlbl_secattr_init(&secattr);
+ rc = netlbl_skbuff_getattr(skb, family, &secattr);
+ if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+ rc = selinux_netlbl_sidlookup_cached(skb, &secattr, sid);
+ else
+ *sid = SECSID_NULL;
+ *type = secattr.type;
+ netlbl_secattr_destroy(&secattr);
+
+ return rc;
+}
+
+/**
+ * selinux_netlbl_skbuff_setsid - Set the NetLabel on a packet given a sid
+ * @skb: the packet
+ * @family: protocol family
+ * @sid: the SID
+ *
+ * Description
+ * Call the NetLabel mechanism to set the label of a packet using @sid.
+ * Returns zero on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
+ u16 family,
+ u32 sid)
+{
+ int rc;
+ struct netlbl_lsm_secattr secattr_storage;
+ struct netlbl_lsm_secattr *secattr = NULL;
+ struct sock *sk;
+
+ /* if this is a locally generated packet check to see if it is already
+ * being labeled by it's parent socket, if it is just exit */
+ sk = skb->sk;
+ if (sk != NULL) {
+ struct sk_security_struct *sksec = sk->sk_security;
+ if (sksec->nlbl_state != NLBL_REQSKB)
+ return 0;
+ secattr = selinux_netlbl_sock_getattr(sk, sid);
+ }
+ if (secattr == NULL) {
+ secattr = &secattr_storage;
+ netlbl_secattr_init(secattr);
+ rc = security_netlbl_sid_to_secattr(sid, secattr);
+ if (rc != 0)
+ goto skbuff_setsid_return;
+ }
+
+ rc = netlbl_skbuff_setattr(skb, family, secattr);
+
+skbuff_setsid_return:
+ if (secattr == &secattr_storage)
+ netlbl_secattr_destroy(secattr);
+ return rc;
+}
+
+/**
+ * selinux_netlbl_inet_conn_request - Label an incoming stream connection
+ * @req: incoming connection request socket
+ *
+ * Description:
+ * A new incoming connection request is represented by @req, we need to label
+ * the new request_sock here and the stack will ensure the on-the-wire label
+ * will get preserved when a full sock is created once the connection handshake
+ * is complete. Returns zero on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
+{
+ int rc;
+ struct netlbl_lsm_secattr secattr;
+
+ if (family != PF_INET)
+ return 0;
+
+ netlbl_secattr_init(&secattr);
+ rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
+ if (rc != 0)
+ goto inet_conn_request_return;
+ rc = netlbl_req_setattr(req, &secattr);
+inet_conn_request_return:
+ netlbl_secattr_destroy(&secattr);
+ return rc;
+}
+
+/**
+ * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
+ * @sk: the new sock
+ *
+ * Description:
+ * A new connection has been established using @sk, we've already labeled the
+ * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
+ * we need to set the NetLabel state here since we now have a sock structure.
+ *
+ */
+void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
+{
+ struct sk_security_struct *sksec = sk->sk_security;
+
+ if (family == PF_INET)
+ sksec->nlbl_state = NLBL_LABELED;
+ else
+ sksec->nlbl_state = NLBL_UNSET;
+}
+
+/**
+ * selinux_netlbl_socket_post_create - Label a socket using NetLabel
+ * @sock: the socket to label
+ * @family: protocol family
+ *
+ * Description:
+ * Attempt to label a socket using the NetLabel mechanism using the given
+ * SID. Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
+{
+ int rc;
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct netlbl_lsm_secattr *secattr;
+
+ if (family != PF_INET)
+ return 0;
+
+ secattr = selinux_netlbl_sock_genattr(sk);
+ if (secattr == NULL)
+ return -ENOMEM;
+ rc = netlbl_sock_setattr(sk, family, secattr);
+ switch (rc) {
+ case 0:
+ sksec->nlbl_state = NLBL_LABELED;
+ break;
+ case -EDESTADDRREQ:
+ sksec->nlbl_state = NLBL_REQSKB;
+ rc = 0;
+ break;
+ }
+
+ return rc;
+}
+
+/**
+ * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
+ * @sksec: the sock's sk_security_struct
+ * @skb: the packet
+ * @family: protocol family
+ * @ad: the audit data
+ *
+ * Description:
+ * Fetch the NetLabel security attributes from @skb and perform an access check
+ * against the receiving socket. Returns zero on success, negative values on
+ * error.
+ *
+ */
+int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+ struct sk_buff *skb,
+ u16 family,
+ struct common_audit_data *ad)
+{
+ int rc;
+ u32 nlbl_sid;
+ u32 perm;
+ struct netlbl_lsm_secattr secattr;
+
+ if (!netlbl_enabled())
+ return 0;
+
+ netlbl_secattr_init(&secattr);
+ rc = netlbl_skbuff_getattr(skb, family, &secattr);
+ if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+ rc = selinux_netlbl_sidlookup_cached(skb, &secattr, &nlbl_sid);
+ else
+ nlbl_sid = SECINITSID_UNLABELED;
+ netlbl_secattr_destroy(&secattr);
+ if (rc != 0)
+ return rc;
+
+ switch (sksec->sclass) {
+ case SECCLASS_UDP_SOCKET:
+ perm = UDP_SOCKET__RECVFROM;
+ break;
+ case SECCLASS_TCP_SOCKET:
+ perm = TCP_SOCKET__RECVFROM;
+ break;
+ default:
+ perm = RAWIP_SOCKET__RECVFROM;
+ }
+
+ rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
+ if (rc == 0)
+ return 0;
+
+ if (nlbl_sid != SECINITSID_UNLABELED)
+ netlbl_skbuff_err(skb, rc, 0);
+ return rc;
+}
+
+/**
+ * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
+ * @sock: the socket
+ * @level: the socket level or protocol
+ * @optname: the socket option name
+ *
+ * Description:
+ * Check the setsockopt() call and if the user is trying to replace the IP
+ * options on a socket and a NetLabel is in place for the socket deny the
+ * access; otherwise allow the access. Returns zero when the access is
+ * allowed, -EACCES when denied, and other negative values on error.
+ *
+ */
+int selinux_netlbl_socket_setsockopt(struct socket *sock,
+ int level,
+ int optname)
+{
+ int rc = 0;
+ struct sock *sk = sock->sk;
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct netlbl_lsm_secattr secattr;
+
+ if (level == IPPROTO_IP && optname == IP_OPTIONS &&
+ (sksec->nlbl_state == NLBL_LABELED ||
+ sksec->nlbl_state == NLBL_CONNLABELED)) {
+ netlbl_secattr_init(&secattr);
+ lock_sock(sk);
+ /* call the netlabel function directly as we want to see the
+ * on-the-wire label that is assigned via the socket's options
+ * and not the cached netlabel/lsm attributes */
+ rc = netlbl_sock_getattr(sk, &secattr);
+ release_sock(sk);
+ if (rc == 0)
+ rc = -EACCES;
+ else if (rc == -ENOMSG)
+ rc = 0;
+ netlbl_secattr_destroy(&secattr);
+ }
+
+ return rc;
+}
+
+/**
+ * selinux_netlbl_socket_connect - Label a client-side socket on connect
+ * @sk: the socket to label
+ * @addr: the destination address
+ *
+ * Description:
+ * Attempt to label a connected socket with NetLabel using the given address.
+ * Returns zero values on success, negative values on failure.
+ *
+ */
+int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
+{
+ int rc;
+ struct sk_security_struct *sksec = sk->sk_security;
+ struct netlbl_lsm_secattr *secattr;
+
+ if (sksec->nlbl_state != NLBL_REQSKB &&
+ sksec->nlbl_state != NLBL_CONNLABELED)
+ return 0;
+
+ lock_sock(sk);
+
+ /* connected sockets are allowed to disconnect when the address family
+ * is set to AF_UNSPEC, if that is what is happening we want to reset
+ * the socket */
+ if (addr->sa_family == AF_UNSPEC) {
+ netlbl_sock_delattr(sk);
+ sksec->nlbl_state = NLBL_REQSKB;
+ rc = 0;
+ goto socket_connect_return;
+ }
+ secattr = selinux_netlbl_sock_genattr(sk);
+ if (secattr == NULL) {
+ rc = -ENOMEM;
+ goto socket_connect_return;
+ }
+ rc = netlbl_conn_setattr(sk, addr, secattr);
+ if (rc == 0)
+ sksec->nlbl_state = NLBL_CONNLABELED;
+
+socket_connect_return:
+ release_sock(sk);
+ return rc;
+}
Code Review / kvmfornfv.git / blobdiff