diff mbox series

[net-next,v4,22/25] ovpn: kill key and notify userspace in case of IV exhaustion

Message ID 20240624113122.12732-23-antonio@openvpn.net (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Introducing OpenVPN Data Channel Offload | expand

Checks

Context Check Description
netdev/series_format fail Series longer than 15 patches
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; GEN HAS DIFF 2 files changed, 2612 insertions(+);
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 842 this patch: 842
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: openvpn-devel@lists.sourceforge.net
netdev/build_clang fail Errors and warnings before: 849 this patch: 853
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 849 this patch: 849
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 57 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

Antonio Quartulli June 24, 2024, 11:31 a.m. UTC
IV wrap-around is cryptographically dangerous for a number of ciphers,
therefore kill the key and inform userspace (via netlink) should the
IV space go exhausted.

Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
---
 drivers/net/ovpn/netlink.c | 39 ++++++++++++++++++++++++++++++++++++++
 drivers/net/ovpn/netlink.h |  8 ++++++++
 2 files changed, 47 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c
index 2e238197d7bc..0cee957e6558 100644
--- a/drivers/net/ovpn/netlink.c
+++ b/drivers/net/ovpn/netlink.c
@@ -846,6 +846,45 @@  int ovpn_nl_del_key_doit(struct sk_buff *skb, struct genl_info *info)
 	return 0;
 }
 
+int ovpn_nl_notify_swap_keys(struct ovpn_peer *peer)
+{
+	struct sk_buff *msg;
+	void *hdr;
+	int ret;
+
+	netdev_info(peer->ovpn->dev, "peer with id %u must rekey - primary key unusable.\n",
+		    peer->id);
+
+	msg = nlmsg_new(100, GFP_ATOMIC);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(msg, 0, 0, &ovpn_nl_family, 0, OVPN_CMD_SWAP_KEYS);
+	if (!hdr) {
+		ret = -ENOBUFS;
+		goto err_free_msg;
+	}
+
+	if (nla_put_u32(msg, OVPN_A_IFINDEX, peer->ovpn->dev->ifindex))
+		goto err_cancel_msg;
+
+	if (nla_put_u32(msg, OVPN_A_PEER_ID, peer->id))
+		goto err_cancel_msg;
+
+	genlmsg_end(msg, hdr);
+
+	genlmsg_multicast_netns(&ovpn_nl_family, dev_net(peer->ovpn->dev), msg,
+				0, OVPN_NLGRP_PEERS, GFP_ATOMIC);
+
+	return 0;
+
+err_cancel_msg:
+	genlmsg_cancel(msg, hdr);
+err_free_msg:
+	nlmsg_free(msg);
+	return ret;
+}
+
 /**
  * ovpn_nl_register - perform any needed registration in the NL subsustem
  */
diff --git a/drivers/net/ovpn/netlink.h b/drivers/net/ovpn/netlink.h
index 9e87cf11d1e9..c86cd102eeef 100644
--- a/drivers/net/ovpn/netlink.h
+++ b/drivers/net/ovpn/netlink.h
@@ -12,4 +12,12 @@ 
 int ovpn_nl_register(void);
 void ovpn_nl_unregister(void);
 
+/**
+ * ovpn_nl_notify_swap_keys - notify userspace peer's key must be renewed
+ * @peer: the peer whose key needs to be renewed
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+int ovpn_nl_notify_swap_keys(struct ovpn_peer *peer);
+
 #endif /* _NET_OVPN_NETLINK_H_ */