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Message-ID: <20240627130843.21042-22-antonio@openvpn.net>
Date: Thu, 27 Jun 2024 15:08:39 +0200
From: Antonio Quartulli <antonio@...nvpn.net>
To: netdev@...r.kernel.org
Cc: kuba@...nel.org,
ryazanov.s.a@...il.com,
pabeni@...hat.com,
edumazet@...gle.com,
andrew@...n.ch,
sd@...asysnail.net,
Antonio Quartulli <antonio@...nvpn.net>
Subject: [PATCH net-next v5 21/25] ovpn: implement key add/del/swap via netlink
This change introduces the netlink commands needed to add, delete and
swap keys for a specific peer.
Userspace is expected to use these commands to create, destroy and
rotate session keys for a specific peer.
Signed-off-by: Antonio Quartulli <antonio@...nvpn.net>
---
Documentation/netlink/specs/ovpn.yaml | 2 +-
drivers/net/ovpn/netlink-gen.c | 2 +-
drivers/net/ovpn/netlink.c | 199 +++++++++++++++++++++++++-
3 files changed, 198 insertions(+), 5 deletions(-)
diff --git a/Documentation/netlink/specs/ovpn.yaml b/Documentation/netlink/specs/ovpn.yaml
index 68ed88d03732..21c89f0bdcbb 100644
--- a/Documentation/netlink/specs/ovpn.yaml
+++ b/Documentation/netlink/specs/ovpn.yaml
@@ -153,7 +153,7 @@ attribute-sets:
decryption
type: u32
checks:
- max: 2
+ max: 7
-
name: cipher-alg
type: u32
diff --git a/drivers/net/ovpn/netlink-gen.c b/drivers/net/ovpn/netlink-gen.c
index 594eb2c50eb5..f7c4c448b263 100644
--- a/drivers/net/ovpn/netlink-gen.c
+++ b/drivers/net/ovpn/netlink-gen.c
@@ -23,7 +23,7 @@ static const struct netlink_range_validation ovpn_a_peer_local_port_range = {
/* Common nested types */
const struct nla_policy ovpn_keyconf_nl_policy[OVPN_A_KEYCONF_DECRYPT_DIR + 1] = {
[OVPN_A_KEYCONF_SLOT] = NLA_POLICY_MAX(NLA_U32, 1),
- [OVPN_A_KEYCONF_KEY_ID] = NLA_POLICY_MAX(NLA_U32, 2),
+ [OVPN_A_KEYCONF_KEY_ID] = NLA_POLICY_MAX(NLA_U32, 7),
[OVPN_A_KEYCONF_CIPHER_ALG] = NLA_POLICY_MAX(NLA_U32, 2),
[OVPN_A_KEYCONF_ENCRYPT_DIR] = NLA_POLICY_NESTED(ovpn_keydir_nl_policy),
[OVPN_A_KEYCONF_DECRYPT_DIR] = NLA_POLICY_NESTED(ovpn_keydir_nl_policy),
diff --git a/drivers/net/ovpn/netlink.c b/drivers/net/ovpn/netlink.c
index e0d35c4ac2fb..31c58cda6a3d 100644
--- a/drivers/net/ovpn/netlink.c
+++ b/drivers/net/ovpn/netlink.c
@@ -638,19 +638,212 @@ int ovpn_nl_del_peer_doit(struct sk_buff *skb, struct genl_info *info)
return ret;
}
+static int ovpn_nl_get_key_dir(struct genl_info *info, struct nlattr *key,
+ enum ovpn_cipher_alg cipher,
+ struct ovpn_key_direction *dir)
+{
+ struct nlattr *attrs[OVPN_A_KEYDIR_MAX + 1];
+ int ret;
+
+ ret = nla_parse_nested(attrs, OVPN_A_KEYDIR_MAX, key,
+ ovpn_keydir_nl_policy, info->extack);
+ if (ret)
+ return ret;
+
+ switch (cipher) {
+ case OVPN_CIPHER_ALG_AES_GCM:
+ case OVPN_CIPHER_ALG_CHACHA20_POLY1305:
+ if (NL_REQ_ATTR_CHECK(info->extack, key, attrs,
+ OVPN_A_KEYDIR_CIPHER_KEY) ||
+ NL_REQ_ATTR_CHECK(info->extack, key, attrs,
+ OVPN_A_KEYDIR_NONCE_TAIL))
+ return -EINVAL;
+
+ dir->cipher_key = nla_data(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
+ dir->cipher_key_size = nla_len(attrs[OVPN_A_KEYDIR_CIPHER_KEY]);
+
+ /* These algorithms require a 96bit nonce,
+ * Construct it by combining 4-bytes packet id and
+ * 8-bytes nonce-tail from userspace
+ */
+ dir->nonce_tail = nla_data(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
+ dir->nonce_tail_size = nla_len(attrs[OVPN_A_KEYDIR_NONCE_TAIL]);
+ break;
+ default:
+ NL_SET_ERR_MSG_MOD(info->extack, "unsupported cipher");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
int ovpn_nl_set_key_doit(struct sk_buff *skb, struct genl_info *info)
{
- return -EOPNOTSUPP;
+ struct nlattr *p_attrs[OVPN_A_PEER_MAX + 1];
+ struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
+ struct ovpn_struct *ovpn = info->user_ptr[0];
+ struct ovpn_peer_key_reset pkr;
+ struct ovpn_peer *peer;
+ u32 peer_id;
+ int ret;
+
+ if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
+ return -EINVAL;
+
+ ret = nla_parse_nested(p_attrs, OVPN_A_PEER_MAX,
+ info->attrs[OVPN_A_PEER], ovpn_peer_nl_policy,
+ info->extack);
+ if (ret)
+ return ret;
+
+ if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], p_attrs,
+ OVPN_A_PEER_ID) ||
+ NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], p_attrs,
+ OVPN_A_PEER_KEYCONF))
+ return -EINVAL;
+
+ ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
+ p_attrs[OVPN_A_PEER_KEYCONF],
+ ovpn_keyconf_nl_policy, info->extack);
+ if (ret)
+ return ret;
+
+ if (NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_SLOT) ||
+ NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_KEY_ID) ||
+ NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_CIPHER_ALG) ||
+ NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_ENCRYPT_DIR) ||
+ NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_DECRYPT_DIR))
+ return -EINVAL;
+
+ peer_id = nla_get_u32(p_attrs[OVPN_A_PEER_ID]);
+ pkr.slot = nla_get_u8(attrs[OVPN_A_KEYCONF_SLOT]);
+ pkr.key.key_id = nla_get_u16(attrs[OVPN_A_KEYCONF_KEY_ID]);
+ pkr.key.cipher_alg = nla_get_u16(attrs[OVPN_A_KEYCONF_CIPHER_ALG]);
+
+ ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_ENCRYPT_DIR],
+ pkr.key.cipher_alg, &pkr.key.encrypt);
+ if (ret < 0)
+ return ret;
+
+ ret = ovpn_nl_get_key_dir(info, attrs[OVPN_A_KEYCONF_DECRYPT_DIR],
+ pkr.key.cipher_alg, &pkr.key.decrypt);
+ if (ret < 0)
+ return ret;
+
+ peer = ovpn_peer_get_by_id(ovpn, peer_id);
+ if (!peer) {
+ NL_SET_ERR_MSG_FMT_MOD(info->extack,
+ "no peer with id %u to set key for",
+ peer_id);
+ return -ENOENT;
+ }
+
+ ret = ovpn_crypto_state_reset(&peer->crypto, &pkr);
+ if (ret < 0) {
+ NL_SET_ERR_MSG_FMT_MOD(info->extack,
+ "cannot install new key for peer %u",
+ peer_id);
+ goto out;
+ }
+
+ netdev_dbg(ovpn->dev, "%s: new key installed (id=%u) for peer %u\n",
+ __func__, pkr.key.key_id, peer_id);
+out:
+ ovpn_peer_put(peer);
+ return ret;
}
int ovpn_nl_swap_keys_doit(struct sk_buff *skb, struct genl_info *info)
{
- return -EOPNOTSUPP;
+ struct ovpn_struct *ovpn = info->user_ptr[0];
+ struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
+ struct ovpn_peer *peer;
+ u32 peer_id;
+ int ret;
+
+ if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
+ return -EINVAL;
+
+ ret = nla_parse_nested(attrs, OVPN_A_PEER_MAX, info->attrs[OVPN_A_PEER],
+ ovpn_peer_nl_policy, info->extack);
+ if (ret)
+ return ret;
+
+ if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], attrs,
+ OVPN_A_PEER_ID))
+ return -EINVAL;
+
+ peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);
+
+ peer = ovpn_peer_get_by_id(ovpn, peer_id);
+ if (!peer) {
+ NL_SET_ERR_MSG_FMT_MOD(info->extack,
+ "no peer with id %u to swap keys for",
+ peer_id);
+ return -ENOENT;
+ }
+
+ ovpn_crypto_key_slots_swap(&peer->crypto);
+ ovpn_peer_put(peer);
+
+ return 0;
}
int ovpn_nl_del_key_doit(struct sk_buff *skb, struct genl_info *info)
{
- return -EOPNOTSUPP;
+ struct nlattr *p_attrs[OVPN_A_PEER_MAX + 1];
+ struct nlattr *attrs[OVPN_A_KEYCONF_MAX + 1];
+ struct ovpn_struct *ovpn = info->user_ptr[0];
+ enum ovpn_key_slot slot;
+ struct ovpn_peer *peer;
+ u32 peer_id;
+ int ret;
+
+ if (GENL_REQ_ATTR_CHECK(info, OVPN_A_PEER))
+ return -EINVAL;
+
+ ret = nla_parse_nested(p_attrs, OVPN_A_PEER_MAX,
+ info->attrs[OVPN_A_PEER], ovpn_peer_nl_policy,
+ info->extack);
+ if (ret)
+ return ret;
+
+ if (NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], p_attrs,
+ OVPN_A_PEER_ID) ||
+ NL_REQ_ATTR_CHECK(info->extack, info->attrs[OVPN_A_PEER], p_attrs,
+ OVPN_A_PEER_KEYCONF))
+ return -EINVAL;
+
+ ret = nla_parse_nested(attrs, OVPN_A_KEYCONF_MAX,
+ p_attrs[OVPN_A_PEER_KEYCONF],
+ ovpn_keyconf_nl_policy, info->extack);
+ if (ret)
+ return ret;
+
+ if (NL_REQ_ATTR_CHECK(info->extack, p_attrs[OVPN_A_PEER_KEYCONF], attrs,
+ OVPN_A_KEYCONF_SLOT))
+ return -EINVAL;
+
+ peer_id = nla_get_u32(p_attrs[OVPN_A_PEER_ID]);
+ slot = nla_get_u8(attrs[OVPN_A_KEYCONF_SLOT]);
+
+ peer = ovpn_peer_get_by_id(ovpn, peer_id);
+ if (!peer) {
+ NL_SET_ERR_MSG_FMT_MOD(info->extack,
+ "no peer with id %u to delete key for",
+ peer_id);
+ return -ENOENT;
+ }
+
+ ovpn_crypto_key_slot_delete(&peer->crypto, slot);
+ ovpn_peer_put(peer);
+
+ return 0;
}
/**
--
2.44.2
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