Smack: IPv6 host labeling
IPv6 appears to be (finally) coming of age with the
influx of autonomous devices. In support of this, add
the ability to associate a Smack label with IPv6 addresses.
This patch also cleans up some of the conditional
compilation associated with the introduction of
secmark processing. It's now more obvious which bit
of code goes with which feature.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d962f88..cc390bc 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -51,9 +51,9 @@
#define SMK_RECEIVING 1
#define SMK_SENDING 2
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_PORT_LABELING
LIST_HEAD(smk_ipv6_port_list);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
static struct kmem_cache *smack_inode_cache;
int smack_enabled;
@@ -2272,7 +2272,7 @@
}
/**
-* smack_host_label - check host based restrictions
+* smack_ipv4host_label - check host based restrictions
* @sip: the object end
*
* looks for host based access restrictions
@@ -2283,30 +2283,96 @@
*
* Returns the label of the far end or NULL if it's not special.
*/
-static struct smack_known *smack_host_label(struct sockaddr_in *sip)
+static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
{
- struct smk_netlbladdr *snp;
+ struct smk_net4addr *snp;
struct in_addr *siap = &sip->sin_addr;
if (siap->s_addr == 0)
return NULL;
- list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
+ list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
+ /*
+ * we break after finding the first match because
+ * the list is sorted from longest to shortest mask
+ * so we have found the most specific match
+ */
+ if (snp->smk_host.s_addr ==
+ (siap->s_addr & snp->smk_mask.s_addr))
+ return snp->smk_label;
+
+ return NULL;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/*
+ * smk_ipv6_localhost - Check for local ipv6 host address
+ * @sip: the address
+ *
+ * Returns boolean true if this is the localhost address
+ */
+static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
+{
+ __be16 *be16p = (__be16 *)&sip->sin6_addr;
+ __be32 *be32p = (__be32 *)&sip->sin6_addr;
+
+ if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
+ ntohs(be16p[7]) == 1)
+ return true;
+ return false;
+}
+
+/**
+* smack_ipv6host_label - check host based restrictions
+* @sip: the object end
+*
+* looks for host based access restrictions
+*
+* This version will only be appropriate for really small sets of single label
+* hosts. The caller is responsible for ensuring that the RCU read lock is
+* taken before calling this function.
+*
+* Returns the label of the far end or NULL if it's not special.
+*/
+static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
+{
+ struct smk_net6addr *snp;
+ struct in6_addr *sap = &sip->sin6_addr;
+ int i;
+ int found = 0;
+
+ /*
+ * It's local. Don't look for a host label.
+ */
+ if (smk_ipv6_localhost(sip))
+ return NULL;
+
+ list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
/*
* we break after finding the first match because
* the list is sorted from longest to shortest mask
* so we have found the most specific match
*/
- if ((&snp->smk_host.sin_addr)->s_addr ==
- (siap->s_addr & (&snp->smk_mask)->s_addr)) {
- /* we have found the special CIPSO option */
- if (snp->smk_label == &smack_cipso_option)
- return NULL;
- return snp->smk_label;
+ for (found = 1, i = 0; i < 8; i++) {
+ /*
+ * If the label is NULL the entry has
+ * been renounced. Ignore it.
+ */
+ if (snp->smk_label == NULL)
+ continue;
+ if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
+ snp->smk_host.s6_addr16[i]) {
+ found = 0;
+ break;
+ }
}
+ if (found)
+ return snp->smk_label;
+ }
return NULL;
}
+#endif /* CONFIG_IPV6 */
/**
* smack_netlabel - Set the secattr on a socket
@@ -2370,7 +2436,7 @@
struct smk_audit_info ad;
rcu_read_lock();
- hkp = smack_host_label(sap);
+ hkp = smack_ipv4host_label(sap);
if (hkp != NULL) {
#ifdef CONFIG_AUDIT
struct lsm_network_audit net;
@@ -2395,7 +2461,42 @@
return smack_netlabel(sk, sk_lbl);
}
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#if IS_ENABLED(CONFIG_IPV6)
+/**
+ * smk_ipv6_check - check Smack access
+ * @subject: subject Smack label
+ * @object: object Smack label
+ * @address: address
+ * @act: the action being taken
+ *
+ * Check an IPv6 access
+ */
+static int smk_ipv6_check(struct smack_known *subject,
+ struct smack_known *object,
+ struct sockaddr_in6 *address, int act)
+{
+#ifdef CONFIG_AUDIT
+ struct lsm_network_audit net;
+#endif
+ struct smk_audit_info ad;
+ int rc;
+
+#ifdef CONFIG_AUDIT
+ smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
+ ad.a.u.net->family = PF_INET6;
+ ad.a.u.net->dport = ntohs(address->sin6_port);
+ if (act == SMK_RECEIVING)
+ ad.a.u.net->v6info.saddr = address->sin6_addr;
+ else
+ ad.a.u.net->v6info.daddr = address->sin6_addr;
+#endif
+ rc = smk_access(subject, object, MAY_WRITE, &ad);
+ rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
+ return rc;
+}
+#endif /* CONFIG_IPV6 */
+
+#ifdef SMACK_IPV6_PORT_LABELING
/**
* smk_ipv6_port_label - Smack port access table management
* @sock: socket
@@ -2479,48 +2580,43 @@
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
int act)
{
- __be16 *bep;
- __be32 *be32p;
struct smk_port_label *spp;
struct socket_smack *ssp = sk->sk_security;
- struct smack_known *skp;
- unsigned short port = 0;
+ struct smack_known *skp = NULL;
+ unsigned short port;
struct smack_known *object;
- struct smk_audit_info ad;
- int rc;
-#ifdef CONFIG_AUDIT
- struct lsm_network_audit net;
-#endif
if (act == SMK_RECEIVING) {
- skp = smack_net_ambient;
+ skp = smack_ipv6host_label(address);
object = ssp->smk_in;
} else {
skp = ssp->smk_out;
- object = smack_net_ambient;
+ object = smack_ipv6host_label(address);
}
/*
- * Get the IP address and port from the address.
+ * The other end is a single label host.
*/
- port = ntohs(address->sin6_port);
- bep = (__be16 *)(&address->sin6_addr);
- be32p = (__be32 *)(&address->sin6_addr);
+ if (skp != NULL && object != NULL)
+ return smk_ipv6_check(skp, object, address, act);
+ if (skp == NULL)
+ skp = smack_net_ambient;
+ if (object == NULL)
+ object = smack_net_ambient;
/*
* It's remote, so port lookup does no good.
*/
- if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
- goto auditout;
+ if (!smk_ipv6_localhost(address))
+ return smk_ipv6_check(skp, object, address, act);
/*
* It's local so the send check has to have passed.
*/
- if (act == SMK_RECEIVING) {
- skp = &smack_known_web;
- goto auditout;
- }
+ if (act == SMK_RECEIVING)
+ return 0;
+ port = ntohs(address->sin6_port);
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
if (spp->smk_port != port)
continue;
@@ -2530,22 +2626,9 @@
break;
}
-auditout:
-
-#ifdef CONFIG_AUDIT
- smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
- ad.a.u.net->family = sk->sk_family;
- ad.a.u.net->dport = port;
- if (act == SMK_RECEIVING)
- ad.a.u.net->v6info.saddr = address->sin6_addr;
- else
- ad.a.u.net->v6info.daddr = address->sin6_addr;
-#endif
- rc = smk_access(skp, object, MAY_WRITE, &ad);
- rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
- return rc;
+ return smk_ipv6_check(skp, object, address, act);
}
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
/**
* smack_inode_setsecurity - set smack xattrs
@@ -2606,10 +2689,10 @@
} else
return -EOPNOTSUPP;
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_PORT_LABELING
if (sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, NULL);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
return 0;
}
@@ -2651,7 +2734,7 @@
return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
}
-#ifndef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_PORT_LABELING
/**
* smack_socket_bind - record port binding information.
* @sock: the socket
@@ -2665,14 +2748,11 @@
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
int addrlen)
{
-#if IS_ENABLED(CONFIG_IPV6)
if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
smk_ipv6_port_label(sock, address);
-#endif
-
return 0;
}
-#endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
/**
* smack_socket_connect - connect access check
@@ -2688,6 +2768,13 @@
int addrlen)
{
int rc = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+ struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+ struct smack_known *rsp;
+ struct socket_smack *ssp = sock->sk->sk_security;
+#endif
if (sock->sk == NULL)
return 0;
@@ -2701,10 +2788,15 @@
case PF_INET6:
if (addrlen < sizeof(struct sockaddr_in6))
return -EINVAL;
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
- rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
+#ifdef SMACK_IPV6_SECMARK_LABELING
+ rsp = smack_ipv6host_label(sip);
+ if (rsp != NULL)
+ rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
SMK_CONNECTING);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
+ rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
+#endif
break;
}
return rc;
@@ -3590,9 +3682,13 @@
int size)
{
struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#if IS_ENABLED(CONFIG_IPV6)
struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+ struct socket_smack *ssp = sock->sk->sk_security;
+ struct smack_known *rsp;
+#endif
int rc = 0;
/*
@@ -3606,9 +3702,15 @@
rc = smack_netlabel_send(sock->sk, sip);
break;
case AF_INET6:
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_SECMARK_LABELING
+ rsp = smack_ipv6host_label(sap);
+ if (rsp != NULL)
+ rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
+ SMK_CONNECTING);
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
break;
}
return rc;
@@ -3822,10 +3924,12 @@
proto = smk_skb_to_addr_ipv6(skb, &sadd);
if (proto != IPPROTO_UDP && proto != IPPROTO_TCP)
break;
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_SECMARK_LABELING
if (skb && skb->secmark != 0)
skp = smack_from_secid(skb->secmark);
else
+ skp = smack_ipv6host_label(&sadd);
+ if (skp == NULL)
skp = smack_net_ambient;
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
@@ -3836,9 +3940,10 @@
rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
MAY_WRITE, rc);
-#else /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_SECMARK_LABELING */
+#ifdef SMACK_IPV6_PORT_LABELING
rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
break;
#endif /* CONFIG_IPV6 */
}
@@ -3936,13 +4041,11 @@
}
netlbl_secattr_destroy(&secattr);
break;
-#if IS_ENABLED(CONFIG_IPV6)
case PF_INET6:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_SECMARK_LABELING
s = skb->secmark;
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
break;
-#endif /* CONFIG_IPV6 */
}
*secid = s;
if (s == 0)
@@ -4065,7 +4168,7 @@
hdr = ip_hdr(skb);
addr.sin_addr.s_addr = hdr->saddr;
rcu_read_lock();
- hskp = smack_host_label(&addr);
+ hskp = smack_ipv4host_label(&addr);
rcu_read_unlock();
if (hskp == NULL)
@@ -4517,9 +4620,9 @@
LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
-#ifndef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_PORT_LABELING
LSM_HOOK_INIT(socket_bind, smack_socket_bind),
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
LSM_HOOK_INIT(socket_connect, smack_socket_connect),
LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
@@ -4614,7 +4717,16 @@
return -ENOMEM;
}
- printk(KERN_INFO "Smack: Initializing.\n");
+ pr_info("Smack: Initializing.\n");
+#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+ pr_info("Smack: Netfilter enabled.\n");
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
+ pr_info("Smack: IPv6 port labeling enabled.\n");
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+ pr_info("Smack: IPv6 Netfilter enabled.\n");
+#endif
/*
* Set the security state for the initial task.