/**
* 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_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_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);
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_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 sk_security_struct *sksec = sk->sk_security;
struct netlbl_lsm_secattr secattr;
u32 nlbl_peer_sid;
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, &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();
}
/**
* netlbl_unlabel_getattr - Get the security attributes for an unlabled packet
* @secattr: the security attributes
*
* Description:
* Determine the security attributes, if any, for an unlabled packet and return
* them in @secattr. Returns zero on success and negative values on failure.
*
*/
int netlbl_unlabel_getattr(struct netlbl_lsm_secattr *secattr)
{
int ret_val;
rcu_read_lock();
if (netlabel_unlabel_acceptflg == 1) {
netlbl_secattr_init(secattr);
ret_val = 0;
} else
ret_val = -ENOMSG;
rcu_read_unlock();
return ret_val;
}
/**
* 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_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 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, 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_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;
netlbl_secattr_init(&secattr);
rc = security_netlbl_sid_to_secattr(sid, &secattr);
if (rc != 0)
goto sock_setsid_return;
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);
}
sock_setsid_return:
netlbl_secattr_destroy(&secattr);
return rc;
}
/**
* 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_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;
}