Skip to content

Commit

Permalink
SELinux: peer secid consolidation for external network labeling
Browse files Browse the repository at this point in the history 
Now that labeled IPsec makes use of the peer_sid field in the
sk_security_struct we can remove a lot of the special cases between labeled
IPsec and NetLabel.  In addition, create a new function,
security_skb_extlbl_sid(), which we can use in several places to get the
security context of the packet's external label which allows us to further
simplify the code in a few places.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
  • Loading branch information
@pcmoore
pcmoore authored and David S. Miller committed Dec 3, 2006
1 parent 9f2ad66 commit 3de4bab
Show file tree
Hide file tree
Showing 6 changed files with 52 additions and 150 deletions.
43 changes: 12 additions & 31 deletions security/selinux/hooks.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3574,27 +3574,16 @@ static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *op
u32 scontext_len;
struct sk_security_struct *ssec;
struct inode_security_struct *isec;
u32 peer_sid = 0;
u32 peer_sid = SECSID_NULL;

isec = SOCK_INODE(sock)->i_security;

/* if UNIX_STREAM check peer_sid, if TCP check dst for labelled sa */
if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET) {
if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
isec->sclass == SECCLASS_TCP_SOCKET) {
ssec = sock->sk->sk_security;
peer_sid = ssec->peer_sid;
}
else if (isec->sclass == SECCLASS_TCP_SOCKET) {
peer_sid = selinux_netlbl_socket_getpeersec_stream(sock);
if (peer_sid == SECSID_NULL) {
ssec = sock->sk->sk_security;
peer_sid = ssec->peer_sid;
}
if (peer_sid == SECSID_NULL) {
err = -ENOPROTOOPT;
goto out;
}
}
else {
if (peer_sid == SECSID_NULL) {
err = -ENOPROTOOPT;
goto out;
}
Expand Down Expand Up @@ -3626,13 +3615,12 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *
u32 peer_secid = SECSID_NULL;
int err = 0;

if (sock && (sock->sk->sk_family == PF_UNIX))
if (sock && sock->sk->sk_family == PF_UNIX)
selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
else if (skb) {
peer_secid = selinux_netlbl_socket_getpeersec_dgram(skb);
if (peer_secid == SECSID_NULL)
peer_secid = selinux_socket_getpeer_dgram(skb);
}
else if (skb)
security_skb_extlbl_sid(skb,
SECINITSID_UNLABELED,
&peer_secid);

if (peer_secid == SECSID_NULL)
err = -EINVAL;
Expand Down Expand Up @@ -3693,17 +3681,10 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
u32 newsid;
u32 peersid;

newsid = selinux_netlbl_inet_conn_request(skb, sksec->sid);
if (newsid != SECSID_NULL) {
req->secid = newsid;
return 0;
}

selinux_skb_xfrm_sid(skb, &peersid);

security_skb_extlbl_sid(skb, SECINITSID_UNLABELED, &peersid);
if (peersid == SECSID_NULL) {
req->secid = sksec->sid;
req->peer_secid = 0;
req->peer_secid = SECSID_NULL;
return 0;
}

Expand Down Expand Up @@ -3738,7 +3719,7 @@ static void selinux_inet_conn_established(struct sock *sk,
{
struct sk_security_struct *sksec = sk->sk_security;

selinux_skb_xfrm_sid(skb, &sksec->peer_sid);
security_skb_extlbl_sid(skb, SECINITSID_UNLABELED, &sksec->peer_sid);
}

static void selinux_req_classify_flow(const struct request_sock *req,
Expand Down
3 changes: 3 additions & 0 deletions security/selinux/include/security.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
#ifndef _SELINUX_SECURITY_H_
#define _SELINUX_SECURITY_H_

#include <linux/skbuff.h>
#include "flask.h"

#define SECSID_NULL 0x00000000 /* unspecified SID */
Expand Down Expand Up @@ -80,6 +81,8 @@ int security_netif_sid(char *name, u32 *if_sid,
int security_node_sid(u16 domain, void *addr, u32 addrlen,
u32 *out_sid);

void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid);

int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
u16 tclass);

Expand Down
28 changes: 9 additions & 19 deletions security/selinux/include/selinux_netlabel.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,14 +38,12 @@

#ifdef CONFIG_NETLABEL
void selinux_netlbl_cache_invalidate(void);
int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid);
int selinux_netlbl_socket_post_create(struct socket *sock);
void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock);
u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid);
int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
struct sk_buff *skb,
struct avc_audit_data *ad);
u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock);
u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb);
void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
int family);
void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
Expand All @@ -62,6 +60,14 @@ static inline void selinux_netlbl_cache_invalidate(void)
return;
}

static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
u32 base_sid,
u32 *sid)
{
*sid = SECSID_NULL;
return 0;
}

static inline int selinux_netlbl_socket_post_create(struct socket *sock)
{
return 0;
Expand All @@ -73,29 +79,13 @@ static inline void selinux_netlbl_sock_graft(struct sock *sk,
return;
}

static inline u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb,
u32 sock_sid)
{
return SECSID_NULL;
}

static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
struct sk_buff *skb,
struct avc_audit_data *ad)
{
return 0;
}

static inline u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
{
return SECSID_NULL;
}

static inline u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
{
return SECSID_NULL;
}

static inline void selinux_netlbl_sk_security_reset(
struct sk_security_struct *ssec,
int family)
Expand Down
5 changes: 0 additions & 5 deletions security/selinux/include/xfrm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,6 @@ int selinux_xfrm_sock_rcv_skb(u32 sid, struct sk_buff *skb,
struct avc_audit_data *ad);
int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
struct avc_audit_data *ad, u8 proto);
u32 selinux_socket_getpeer_dgram(struct sk_buff *skb);
int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
#else
static inline int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
Expand All @@ -51,10 +50,6 @@ static inline int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
return 0;
}

static inline int selinux_socket_getpeer_dgram(struct sk_buff *skb)
{
return SECSID_NULL;
}
static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
{
*sid = SECSID_NULL;
Expand Down
90 changes: 28 additions & 62 deletions security/selinux/ss/services.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,7 @@
#include "mls.h"
#include "objsec.h"
#include "selinux_netlabel.h"
#include "xfrm.h"

extern void selnl_notify_policyload(u32 seqno);
unsigned int policydb_loaded_version;
Expand Down Expand Up @@ -2191,6 +2192,32 @@ void selinux_audit_set_callback(int (*callback)(void))
aurule_callback = callback;
}

/**
* security_skb_extlbl_sid - Determine the external label of a packet
* @skb: the packet
* @base_sid: the SELinux SID to use as a context for MLS only external labels
* @sid: the packet's SID
*
* Description:
* Check the various different forms of external packet labeling and determine
* the external SID for the packet.
*
*/
void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid)
{
u32 xfrm_sid;
u32 nlbl_sid;

selinux_skb_xfrm_sid(skb, &xfrm_sid);
if (selinux_netlbl_skbuff_getsid(skb,
(xfrm_sid == SECSID_NULL ?
base_sid : xfrm_sid),
&nlbl_sid) != 0)
nlbl_sid = SECSID_NULL;

*sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
}

#ifdef CONFIG_NETLABEL
/*
* This is the structure we store inside the NetLabel cache block.
Expand Down Expand Up @@ -2408,9 +2435,7 @@ static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
* assign to the packet. Returns zero on success, negative values on failure.
*
*/
static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
u32 base_sid,
u32 *sid)
int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
{
int rc;
struct netlbl_lsm_secattr secattr;
Expand Down Expand Up @@ -2615,29 +2640,6 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
rcu_read_unlock();
}

/**
* selinux_netlbl_inet_conn_request - Handle a new connection request
* @skb: the packet
* @sock_sid: the SID of the parent socket
*
* Description:
* If present, use the security attributes of the packet in @skb and the
* parent sock's SID to arrive at a SID for the new child sock. Returns the
* SID of the connection or SECSID_NULL on failure.
*
*/
u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid)
{
int rc;
u32 peer_sid;

rc = selinux_netlbl_skbuff_getsid(skb, sock_sid, &peer_sid);
if (rc != 0)
return SECSID_NULL;

return peer_sid;
}

/**
* selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
* @inode: the file descriptor's inode
Expand Down Expand Up @@ -2727,42 +2729,6 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
return rc;
}

/**
* selinux_netlbl_socket_getpeersec_stream - Return the connected peer's SID
* @sock: the socket
*
* Description:
* Examine @sock to find the connected peer's SID. Returns the SID on success
* or SECSID_NULL on error.
*
*/
u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
{
struct sk_security_struct *sksec = sock->sk->sk_security;
return sksec->peer_sid;
}

/**
* selinux_netlbl_socket_getpeersec_dgram - Return the SID of a NetLabel packet
* @skb: the packet
*
* Description:
* Examine @skb to find the SID assigned to it by NetLabel. Returns the SID on
* success, SECSID_NULL on error.
*
*/
u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
{
int peer_sid;

if (selinux_netlbl_skbuff_getsid(skb,
SECINITSID_UNLABELED,
&peer_sid) != 0)
return SECSID_NULL;

return peer_sid;
}

/**
* selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
* @sock: the socket
Expand Down
33 changes: 0 additions & 33 deletions security/selinux/xfrm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -372,39 +372,6 @@ void selinux_xfrm_state_free(struct xfrm_state *x)
kfree(ctx);
}

/*
* SELinux internal function to retrieve the context of a UDP packet
* based on its security association.
*
* Retrieve via setsockopt IP_PASSSEC and recvmsg with control message
* type SCM_SECURITY.
*/
u32 selinux_socket_getpeer_dgram(struct sk_buff *skb)
{
struct sec_path *sp;

if (skb == NULL)
return SECSID_NULL;

if (skb->sk->sk_protocol != IPPROTO_UDP)
return SECSID_NULL;

sp = skb->sp;
if (sp) {
int i;

for (i = sp->len-1; i >= 0; i--) {
struct xfrm_state *x = sp->xvec[i];
if (selinux_authorizable_xfrm(x)) {
struct xfrm_sec_ctx *ctx = x->security;
return ctx->ctx_sid;
}
}
}

return SECSID_NULL;
}

/*
* LSM hook implementation that authorizes deletion of labeled SAs.
*/
Expand Down

0 comments on commit 3de4bab

Please sign in to comment.