| /* |
| * SELinux NetLabel Support |
| * |
| * This file provides the necessary glue to tie NetLabel into the SELinux |
| * subsystem. |
| * |
| * Author: Paul Moore <paul.moore@hp.com> |
| * |
| */ |
| |
| /* |
| * (c) Copyright Hewlett-Packard Development Company, L.P., 2007 |
| * |
| * 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 <net/sock.h> |
| #include <net/netlabel.h> |
| |
| #include "objsec.h" |
| #include "security.h" |
| |
| /** |
| * selinux_netlbl_sock_setsid - Label a socket using the NetLabel mechanism |
| * @sk: the socket to label |
| * @sid: the SID to use |
| * |
| * Description: |
| * Attempt to label a socket using the NetLabel mechanism using the given |
| * SID. Returns zero values on success, negative values on failure. The |
| * caller is responsibile for calling rcu_read_lock() before calling this |
| * this function and rcu_read_unlock() after this function returns. |
| * |
| */ |
| static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid) |
| { |
| int rc; |
| struct sk_security_struct *sksec = sk->sk_security; |
| struct netlbl_lsm_secattr secattr; |
| |
| rc = security_netlbl_sid_to_secattr(sid, &secattr); |
| if (rc != 0) |
| return rc; |
| |
| rc = netlbl_sock_setattr(sk, &secattr); |
| if (rc == 0) { |
| spin_lock_bh(&sksec->nlbl_lock); |
| sksec->nlbl_state = NLBL_LABELED; |
| spin_unlock_bh(&sksec->nlbl_lock); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * 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_sk_security_reset - Reset the NetLabel fields |
| * @ssec: 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 responsibile for all the NetLabel sk_security_struct locking. |
| * |
| */ |
| void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec, |
| int family) |
| { |
| if (family == PF_INET) |
| ssec->nlbl_state = NLBL_REQUIRE; |
| else |
| ssec->nlbl_state = NLBL_UNSET; |
| } |
| |
| /** |
| * selinux_netlbl_sk_security_init - Setup the NetLabel fields |
| * @ssec: the sk_security_struct |
| * @family: the socket family |
| * |
| * Description: |
| * Called when a new sk_security_struct is allocated to initialize the NetLabel |
| * fields. |
| * |
| */ |
| void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec, |
| int family) |
| { |
| /* No locking needed, we are the only one who has access to ssec */ |
| selinux_netlbl_sk_security_reset(ssec, family); |
| spin_lock_init(&ssec->nlbl_lock); |
| } |
| |
| /** |
| * selinux_netlbl_sk_security_clone - Copy the NetLabel fields |
| * @ssec: the original sk_security_struct |
| * @newssec: the cloned sk_security_struct |
| * |
| * Description: |
| * Clone the NetLabel specific sk_security_struct fields from @ssec to |
| * @newssec. |
| * |
| */ |
| void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec, |
| struct sk_security_struct *newssec) |
| { |
| /* We don't need to take newssec->nlbl_lock because we are the only |
| * thread with access to newssec, but we do need to take the RCU read |
| * lock as other threads could have access to ssec */ |
| rcu_read_lock(); |
| selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family); |
| newssec->sclass = ssec->sclass; |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel |
| * @skb: the packet |
| * @base_sid: the SELinux SID to use as a context for MLS only attributes |
| * @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, u32 base_sid, 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, &secattr); |
| if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) { |
| rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid); |
| if (rc == 0 && |
| (secattr.flags & NETLBL_SECATTR_CACHEABLE) && |
| (secattr.flags & NETLBL_SECATTR_CACHE)) |
| netlbl_cache_add(skb, &secattr); |
| } else |
| *sid = SECSID_NULL; |
| netlbl_secattr_destroy(&secattr); |
| |
| return rc; |
| } |
| |
| /** |
| * selinux_netlbl_sock_graft - Netlabel the new socket |
| * @sk: the new connection |
| * @sock: the new socket |
| * |
| * Description: |
| * The connection represented by @sk is being grafted onto @sock so set the |
| * socket's NetLabel to match the SID of @sk. |
| * |
| */ |
| void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) |
| { |
| struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; |
| struct sk_security_struct *sksec = sk->sk_security; |
| struct netlbl_lsm_secattr secattr; |
| u32 nlbl_peer_sid; |
| |
| sksec->sclass = isec->sclass; |
| |
| rcu_read_lock(); |
| |
| if (sksec->nlbl_state != NLBL_REQUIRE) { |
| rcu_read_unlock(); |
| return; |
| } |
| |
| netlbl_secattr_init(&secattr); |
| if (netlbl_sock_getattr(sk, &secattr) == 0 && |
| secattr.flags != NETLBL_SECATTR_NONE && |
| security_netlbl_secattr_to_sid(&secattr, |
| SECINITSID_NETMSG, |
| &nlbl_peer_sid) == 0) |
| sksec->peer_sid = nlbl_peer_sid; |
| netlbl_secattr_destroy(&secattr); |
| |
| /* Try to set the NetLabel on the socket to save time later, if we fail |
| * here we will pick up the pieces in later calls to |
| * selinux_netlbl_inode_permission(). */ |
| selinux_netlbl_sock_setsid(sk, sksec->sid); |
| |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * selinux_netlbl_socket_post_create - Label a socket using NetLabel |
| * @sock: the socket to label |
| * |
| * 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 socket *sock) |
| { |
| int rc = 0; |
| struct sock *sk = sock->sk; |
| struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; |
| struct sk_security_struct *sksec = sk->sk_security; |
| |
| sksec->sclass = isec->sclass; |
| |
| rcu_read_lock(); |
| if (sksec->nlbl_state == NLBL_REQUIRE) |
| rc = selinux_netlbl_sock_setsid(sk, sksec->sid); |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled |
| * @inode: the file descriptor's inode |
| * @mask: the permission mask |
| * |
| * Description: |
| * Looks at a file's inode and if it is marked as a socket protected by |
| * NetLabel then verify that the socket has been labeled, if not try to label |
| * the socket now with the inode's SID. Returns zero on success, negative |
| * values on failure. |
| * |
| */ |
| int selinux_netlbl_inode_permission(struct inode *inode, int mask) |
| { |
| int rc; |
| struct sock *sk; |
| struct socket *sock; |
| struct sk_security_struct *sksec; |
| |
| if (!S_ISSOCK(inode->i_mode) || |
| ((mask & (MAY_WRITE | MAY_APPEND)) == 0)) |
| return 0; |
| sock = SOCKET_I(inode); |
| sk = sock->sk; |
| sksec = sk->sk_security; |
| |
| rcu_read_lock(); |
| if (sksec->nlbl_state != NLBL_REQUIRE) { |
| rcu_read_unlock(); |
| return 0; |
| } |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| rc = selinux_netlbl_sock_setsid(sk, sksec->sid); |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel |
| * @sksec: the sock's sk_security_struct |
| * @skb: the packet |
| * @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, |
| struct avc_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, &secattr); |
| if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) { |
| rc = security_netlbl_secattr_to_sid(&secattr, |
| SECINITSID_NETMSG, |
| &nlbl_sid); |
| if (rc == 0 && |
| (secattr.flags & NETLBL_SECATTR_CACHEABLE) && |
| (secattr.flags & NETLBL_SECATTR_CACHE)) |
| netlbl_cache_add(skb, &secattr); |
| } 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); |
| 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; |
| |
| rcu_read_lock(); |
| if (level == IPPROTO_IP && optname == IP_OPTIONS && |
| sksec->nlbl_state == NLBL_LABELED) { |
| netlbl_secattr_init(&secattr); |
| lock_sock(sk); |
| rc = netlbl_sock_getattr(sk, &secattr); |
| release_sock(sk); |
| if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) |
| rc = -EACCES; |
| netlbl_secattr_destroy(&secattr); |
| } |
| rcu_read_unlock(); |
| |
| return rc; |
| } |