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-rw-r--r--security/selinux/netlabel.c280
1 files changed, 239 insertions, 41 deletions
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 89b418392f1..f58701a7b72 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -9,7 +9,7 @@
*/
/*
- * (c) Copyright Hewlett-Packard Development Company, L.P., 2007
+ * (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
@@ -29,8 +29,12 @@
#include <linux/spinlock.h>
#include <linux/rcupdate.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"
@@ -64,32 +68,69 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
}
/**
+ * 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_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.
+ * Attempt to label a socket using the NetLabel mechanism. Returns zero values
+ * on success, negative values on failure.
*
*/
-static int selinux_netlbl_sock_setsid(struct sock *sk, u32 sid)
+static int selinux_netlbl_sock_setsid(struct sock *sk)
{
int rc;
struct sk_security_struct *sksec = sk->sk_security;
- struct netlbl_lsm_secattr secattr;
+ struct netlbl_lsm_secattr *secattr;
- netlbl_secattr_init(&secattr);
+ if (sksec->nlbl_state != NLBL_REQUIRE)
+ return 0;
- rc = security_netlbl_sid_to_secattr(sid, &secattr);
- if (rc != 0)
- goto sock_setsid_return;
- rc = netlbl_sock_setattr(sk, &secattr);
- if (rc == 0)
+ secattr = selinux_netlbl_sock_genattr(sk);
+ if (secattr == NULL)
+ return -ENOMEM;
+ rc = netlbl_sock_setattr(sk, secattr);
+ switch (rc) {
+ case 0:
sksec->nlbl_state = NLBL_LABELED;
+ break;
+ case -EDESTADDRREQ:
+ sksec->nlbl_state = NLBL_REQSKB;
+ rc = 0;
+ break;
+ }
-sock_setsid_return:
- netlbl_secattr_destroy(&secattr);
return rc;
}
@@ -106,6 +147,38 @@ void selinux_netlbl_cache_invalidate(void)
}
/**
+ * 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
+ * @sssec: 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 *ssec)
+{
+ if (ssec->nlbl_secattr != NULL)
+ netlbl_secattr_free(ssec->nlbl_secattr);
+}
+
+/**
* selinux_netlbl_sk_security_reset - Reset the NetLabel fields
* @ssec: the sk_security_struct
* @family: the socket family
@@ -163,35 +236,118 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
}
/**
- * selinux_netlbl_sock_graft - Netlabel the new socket
+ * 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 auccess, 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 = sksec->nlbl_secattr;
+ }
+ 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_established - Netlabel the newly accepted connection
* @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.
+ * A new connection has been established on @sk so make sure it is labeled
+ * correctly with the NetLabel susbsystem.
*
*/
-void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
+void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family)
{
+ int rc;
struct sk_security_struct *sksec = sk->sk_security;
- struct netlbl_lsm_secattr secattr;
- u32 nlbl_peer_sid;
+ struct netlbl_lsm_secattr *secattr;
+ struct inet_sock *sk_inet = inet_sk(sk);
+ struct sockaddr_in addr;
if (sksec->nlbl_state != NLBL_REQUIRE)
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);
+ secattr = selinux_netlbl_sock_genattr(sk);
+ if (secattr == NULL)
+ return;
- /* 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);
+ rc = netlbl_sock_setattr(sk, secattr);
+ switch (rc) {
+ case 0:
+ sksec->nlbl_state = NLBL_LABELED;
+ break;
+ case -EDESTADDRREQ:
+ /* no PF_INET6 support yet because we don't support any IPv6
+ * labeling protocols */
+ if (family != PF_INET) {
+ sksec->nlbl_state = NLBL_UNSET;
+ return;
+ }
+
+ addr.sin_family = family;
+ addr.sin_addr.s_addr = sk_inet->daddr;
+ if (netlbl_conn_setattr(sk, (struct sockaddr *)&addr,
+ secattr) != 0) {
+ /* we failed to label the connected socket (could be
+ * for a variety of reasons, the actual "why" isn't
+ * important here) so we have to go to our backup plan,
+ * labeling the packets individually in the netfilter
+ * local output hook. this is okay but we need to
+ * adjust the MSS of the connection to take into
+ * account any labeling overhead, since we don't know
+ * the exact overhead at this point we'll use the worst
+ * case value which is 40 bytes for IPv4 */
+ struct inet_connection_sock *sk_conn = inet_csk(sk);
+ sk_conn->icsk_ext_hdr_len += 40 -
+ (sk_inet->opt ? sk_inet->opt->optlen : 0);
+ sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
+
+ sksec->nlbl_state = NLBL_REQSKB;
+ } else
+ sksec->nlbl_state = NLBL_CONNLABELED;
+ break;
+ default:
+ /* note that we are failing to label the socket which could be
+ * a bad thing since it means traffic could leave the system
+ * without the desired labeling, however, all is not lost as
+ * we have a check in selinux_netlbl_inode_permission() to
+ * pick up the pieces that we might drop here because we can't
+ * return an error code */
+ break;
+ }
}
/**
@@ -205,13 +361,7 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
*/
int selinux_netlbl_socket_post_create(struct socket *sock)
{
- struct sock *sk = sock->sk;
- struct sk_security_struct *sksec = sk->sk_security;
-
- if (sksec->nlbl_state != NLBL_REQUIRE)
- return 0;
-
- return selinux_netlbl_sock_setsid(sk, sksec->sid);
+ return selinux_netlbl_sock_setsid(sock->sk);
}
/**
@@ -246,7 +396,7 @@ int selinux_netlbl_inode_permission(struct inode *inode, int mask)
local_bh_disable();
bh_lock_sock_nested(sk);
if (likely(sksec->nlbl_state == NLBL_REQUIRE))
- rc = selinux_netlbl_sock_setsid(sk, sksec->sid);
+ rc = selinux_netlbl_sock_setsid(sk);
else
rc = 0;
bh_unlock_sock(sk);
@@ -307,7 +457,7 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
return 0;
if (nlbl_sid != SECINITSID_UNLABELED)
- netlbl_skbuff_err(skb, rc);
+ netlbl_skbuff_err(skb, rc, 0);
return rc;
}
@@ -334,7 +484,8 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
struct netlbl_lsm_secattr secattr;
if (level == IPPROTO_IP && optname == IP_OPTIONS &&
- sksec->nlbl_state == NLBL_LABELED) {
+ (sksec->nlbl_state == NLBL_LABELED ||
+ sksec->nlbl_state == NLBL_CONNLABELED)) {
netlbl_secattr_init(&secattr);
lock_sock(sk);
rc = netlbl_sock_getattr(sk, &secattr);
@@ -346,3 +497,50 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
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;
+
+ local_bh_disable();
+ bh_lock_sock_nested(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:
+ bh_unlock_sock(sk);
+ local_bh_enable();
+ return rc;
+}