[PATCH ghak90 V6 10/10] audit: NETFILTER_PKT: record each container ID associated with a netNS

[Richard Guy Briggs <rgb@xxxxxxxxxx>]

Add audit container identifier auxiliary record(s) to NETFILTER_PKT
event standalone records.  Iterate through all potential audit container
identifiers associated with a network namespace.

Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
---
 include/linux/audit.h    |  5 +++++
 kernel/audit.c           | 39 +++++++++++++++++++++++++++++++++++++++
 net/netfilter/nft_log.c  | 11 +++++++++--
 net/netfilter/xt_AUDIT.c | 11 +++++++++--
 4 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 4b2503927c37..d43db4491dd1 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -220,6 +220,8 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
 extern void audit_netns_contid_del(struct net *net, u64 contid);
 extern void audit_switch_task_namespaces(struct nsproxy *ns,
 					 struct task_struct *p);
+extern void audit_log_netns_contid_list(struct net *net,
+					struct audit_context *context);
 
 extern u32 audit_enabled;
 #else /* CONFIG_AUDIT */
@@ -296,6 +298,9 @@ static inline void audit_netns_contid_del(struct net *net, u64 contid)
 static inline void audit_switch_task_namespaces(struct nsproxy *ns,
 						struct task_struct *p)
 { }
+static inline void audit_log_netns_contid_list(struct net *net,
+					       struct audit_context *context)
+{ }
 
 #define audit_enabled AUDIT_OFF
 #endif /* CONFIG_AUDIT */
diff --git a/kernel/audit.c b/kernel/audit.c
index 996213591617..512464a626d1 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -453,6 +453,45 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
 		audit_netns_contid_add(new->net_ns, contid);
 }
 
+/**
+ * audit_log_netns_contid_list - List contids for the given network namespace
+ * @net: the network namespace of interest
+ * @context: the audit context to use
+ *
+ * Description:
+ * Issues a CONTAINER_ID record with a CSV list of contids associated
+ * with a network namespace to accompany a NETFILTER_PKT record.
+ */
+void audit_log_netns_contid_list(struct net *net, struct audit_context *context)
+{
+	struct audit_buffer *ab = NULL;
+	struct audit_contid *cont;
+	struct audit_net *aunet;
+
+	/* Generate AUDIT_CONTAINER_ID record with container ID CSV list */
+	rcu_read_lock();
+	aunet = net_generic(net, audit_net_id);
+	if (!aunet)
+		goto out;
+	list_for_each_entry_rcu(cont, &aunet->contid_list, list) {
+		if (!ab) {
+			ab = audit_log_start(context, GFP_ATOMIC,
+					     AUDIT_CONTAINER_ID);
+			if (!ab) {
+				audit_log_lost("out of memory in audit_log_netns_contid_list");
+				goto out;
+			}
+			audit_log_format(ab, "contid=");
+		} else
+			audit_log_format(ab, ",");
+		audit_log_format(ab, "%llu", (unsigned long long)cont->id);
+	}
+	audit_log_end(ab);
+out:
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(audit_log_netns_contid_list);
+
 void audit_panic(const char *message)
 {
 	switch (audit_failure) {
diff --git a/net/netfilter/nft_log.c b/net/netfilter/nft_log.c
index 655187bed5d8..bdb1ec2368a7 100644
--- a/net/netfilter/nft_log.c
+++ b/net/netfilter/nft_log.c
@@ -69,13 +69,16 @@ static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
 	struct sk_buff *skb = pkt->skb;
 	struct audit_buffer *ab;
 	int fam = -1;
+	struct audit_context *context;
+	struct net *net;
 
 	if (!audit_enabled)
 		return;
 
-	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
+	context = audit_alloc_local(GFP_ATOMIC);
+	ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
 	if (!ab)
-		return;
+		goto errout;
 
 	audit_log_format(ab, "mark=%#x", skb->mark);
 
@@ -102,6 +105,10 @@ static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
 		audit_log_format(ab, " saddr=? daddr=? proto=-1");
 
 	audit_log_end(ab);
+	net = xt_net(&pkt->xt);
+	audit_log_netns_contid_list(net, context);
+errout:
+	audit_free_context(context);
 }
 
 static void nft_log_eval(const struct nft_expr *expr,
diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c
index af883f1b64f9..a3e547435f13 100644
--- a/net/netfilter/xt_AUDIT.c
+++ b/net/netfilter/xt_AUDIT.c
@@ -71,10 +71,13 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 {
 	struct audit_buffer *ab;
 	int fam = -1;
+	struct audit_context *context;
+	struct net *net;
 
 	if (audit_enabled == AUDIT_OFF)
-		goto errout;
-	ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
+		goto out;
+	context = audit_alloc_local(GFP_ATOMIC);
+	ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
 	if (ab == NULL)
 		goto errout;
 
@@ -104,7 +107,11 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 
 	audit_log_end(ab);
 
+	net = xt_net(par);
+	audit_log_netns_contid_list(net, context);
 errout:
+	audit_free_context(context);
+out:
 	return XT_CONTINUE;
 }
 
-- 
1.8.3.1