Smack: Consolidate uses of secmark into a function

Add a function smack_from_skb() that returns the Smack label
identified by a network secmark. Replace the explicit uses of
the secmark with this function.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Casey Schaufler 2020-08-11 17:39:41 -07:00 committed by Casey Schaufler
parent d012a7190f
commit 36be81293d

View File

@ -3810,6 +3810,20 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
}
#endif /* CONFIG_IPV6 */
/**
* smack_from_skb - Smack data from the secmark in an skb
* @skb: packet
*
* Returns smack_known of the secmark or NULL if that won't work.
*/
static struct smack_known *smack_from_skb(struct sk_buff *skb)
{
if (skb == NULL || skb->secmark == 0)
return NULL;
return smack_from_secid(skb->secmark);
}
/**
* smack_socket_sock_rcv_skb - Smack packet delivery access check
* @sk: socket
@ -3838,17 +3852,14 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
switch (family) {
case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
/*
* If there is a secmark use it rather than the CIPSO label.
* If there is no secmark fall back to CIPSO.
* The secmark is assumed to reflect policy better.
*/
if (skb && skb->secmark != 0) {
skp = smack_from_secid(skb->secmark);
skp = smack_from_skb(skb);
if (skp)
goto access_check;
}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
/*
* Translate what netlabel gave us.
*/
@ -3862,9 +3873,8 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
netlbl_secattr_destroy(&secattr);
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
@ -3890,16 +3900,14 @@ access_check:
proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
break;
#ifdef SMACK_IPV6_SECMARK_LABELING
if (skb && skb->secmark != 0)
skp = smack_from_secid(skb->secmark);
else if (smk_ipv6_localhost(&sadd))
skp = smack_from_skb(skb);
if (skp == NULL) {
if (smk_ipv6_localhost(&sadd))
break;
else
skp = smack_ipv6host_label(&sadd);
if (skp == NULL)
skp = smack_net_ambient;
if (skb == NULL)
break;
}
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
@ -3995,11 +4003,11 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
s = ssp->smk_out->smk_secid;
break;
case PF_INET:
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
s = skb->secmark;
if (s != 0)
skp = smack_from_skb(skb);
if (skp) {
s = skp->smk_secid;
break;
#endif
}
/*
* Translate what netlabel gave us.
*/
@ -4015,7 +4023,9 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
break;
case PF_INET6:
#ifdef SMACK_IPV6_SECMARK_LABELING
s = skb->secmark;
skp = smack_from_skb(skb);
if (skp)
s = skp->smk_secid;
#endif
break;
}
@ -4087,17 +4097,14 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
}
#endif /* CONFIG_IPV6 */
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
/*
* If there is a secmark use it rather than the CIPSO label.
* If there is no secmark fall back to CIPSO.
* The secmark is assumed to reflect policy better.
*/
if (skb && skb->secmark != 0) {
skp = smack_from_secid(skb->secmark);
skp = smack_from_skb(skb);
if (skp)
goto access_check;
}
#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
@ -4107,9 +4114,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
skp = &smack_known_huh;
netlbl_secattr_destroy(&secattr);
#ifdef CONFIG_SECURITY_SMACK_NETFILTER
access_check:
#endif
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);