[RFC PATCH 2/3] gtp: Add LSM hooks to GPRS Tunneling Protocol (GTP)

Richard Haines richard_c_haines at btinternet.com
Sat Oct 17 05:01:08 UTC 2020


Add security hooks to allow security modules to exercise access control
over GTP.

Signed-off-by: Richard Haines <richard_c_haines at btinternet.com>
---
 drivers/net/gtp.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 21640a035..ee00b12ab 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -73,6 +73,8 @@ struct gtp_dev {
 	unsigned int		hash_size;
 	struct hlist_head	*tid_hash;
 	struct hlist_head	*addr_hash;
+
+	void			*security;
 };
 
 static unsigned int gtp_net_id __read_mostly;
@@ -663,6 +665,12 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
 
 	gtp = netdev_priv(dev);
 
+	err = security_gtp_dev_add(&gtp->security);
+	pr_debug("security_gtp_dev_add() ptr: %p err: %d\n",
+		 gtp->security, err);
+	if (err < 0)
+		return err;
+
 	err = gtp_encap_enable(gtp, data);
 	if (err < 0)
 		return err;
@@ -705,7 +713,15 @@ static void gtp_dellink(struct net_device *dev, struct list_head *head)
 {
 	struct gtp_dev *gtp = netdev_priv(dev);
 	struct pdp_ctx *pctx;
-	int i;
+	int i, err;
+
+	err = security_gtp_dev_del(gtp->security);
+	pr_debug("security_gtp_dev_del() ptr: %p err: %d\n",
+		 gtp->security, err);
+	if (err < 0) {
+		pr_err("Failed security_gtp_dev_del_link() err: %d\n", err);
+		return;
+	}
 
 	for (i = 0; i < gtp->hash_size; i++)
 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
@@ -1076,6 +1092,12 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 		goto out_unlock;
 	}
 
+	err = security_gtp_dev_cmd(gtp->security, GTP_CMD_NEWPDP);
+	pr_debug("security_gtp_dev_cmd(GTP_CMD_NEWPDP) ptr: %p err: %d\n",
+		 gtp->security, err);
+	if (err < 0)
+		goto out_unlock;
+
 	if (version == GTP_V0)
 		sk = gtp->sk0;
 	else if (version == GTP_V1)
@@ -1139,6 +1161,7 @@ static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pdp_ctx *pctx;
+	struct gtp_dev *gtp;
 	int err = 0;
 
 	if (!info->attrs[GTPA_VERSION])
@@ -1152,6 +1175,13 @@ static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
 		goto out_unlock;
 	}
 
+	gtp = netdev_priv(pctx->dev);
+	err = security_gtp_dev_cmd(gtp->security, GTP_CMD_DELPDP);
+	pr_debug("security_gtp_dev_cmd(GTP_CMD_DELPDP) ptr: %p err: %d\n",
+		 gtp->security, err);
+	if (err < 0)
+		goto out_unlock;
+
 	if (pctx->gtp_version == GTP_V0)
 		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
 			   pctx->u.v0.tid, pctx);
@@ -1208,6 +1238,7 @@ static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pdp_ctx *pctx = NULL;
 	struct sk_buff *skb2;
+	struct gtp_dev *gtp;
 	int err;
 
 	if (!info->attrs[GTPA_VERSION])
@@ -1221,6 +1252,13 @@ static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
 		goto err_unlock;
 	}
 
+	gtp = netdev_priv(pctx->dev);
+	err = security_gtp_dev_cmd(gtp->security, GTP_CMD_GETPDP);
+	pr_debug("security_gtp_dev_cmd(GTP_CMD_GETPDP) ptr: %p err: %d\n",
+		 gtp->security, err);
+	if (err < 0)
+		goto err_unlock;
+
 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
 	if (skb2 == NULL) {
 		err = -ENOMEM;
@@ -1250,6 +1288,7 @@ static int gtp_genl_dump_pdp(struct sk_buff *skb,
 	struct net *net = sock_net(skb->sk);
 	struct pdp_ctx *pctx;
 	struct gtp_net *gn;
+	int err;
 
 	gn = net_generic(net, gtp_net_id);
 
@@ -1263,6 +1302,14 @@ static int gtp_genl_dump_pdp(struct sk_buff *skb,
 		else
 			last_gtp = NULL;
 
+		err = security_gtp_dev_cmd(gtp->security, GTP_CMD_GETPDP);
+		pr_debug("security_gtp_dev_cmd(GTP_CMD_GETPDP) ptr: %p err: %d\n",
+			 gtp->security, err);
+		if (err < 0) {
+			rcu_read_unlock();
+			return err;
+		}
+
 		for (i = bucket; i < gtp->hash_size; i++) {
 			j = 0;
 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
-- 
2.26.2



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