On 16/10/2024 10:27, Jiri Pirko wrote:
Wed, Oct 16, 2024 at 03:03:04AM CEST, anto...@openvpn.net wrote:
Add basic infrastructure for handling ovpn interfaces.
Signed-off-by: Antonio Quartulli <anto...@openvpn.net>
---
drivers/net/ovpn/main.c | 115 ++++++++++++++++++++++++++++++++++++++++--
drivers/net/ovpn/main.h | 7 +++
drivers/net/ovpn/ovpnstruct.h | 8 +++
drivers/net/ovpn/packet.h | 40 +++++++++++++++
include/uapi/linux/if_link.h | 15 ++++++
5 files changed, 180 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c
index
d5bdb0055f4dd3a6e32dc6e792bed1e7fd59e101..eead7677b8239eb3c48bb26ca95492d88512b8d4
100644
--- a/drivers/net/ovpn/main.c
+++ b/drivers/net/ovpn/main.c
@@ -10,18 +10,52 @@
#include <linux/genetlink.h>
#include <linux/module.h>
#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <net/ip.h>
#include <net/rtnetlink.h>
-#include <uapi/linux/ovpn.h>
+#include <uapi/linux/if_arp.h>
#include "ovpnstruct.h"
#include "main.h"
#include "netlink.h"
#include "io.h"
+#include "packet.h"
/* Driver info */
#define DRV_DESCRIPTION "OpenVPN data channel offload (ovpn)"
#define DRV_COPYRIGHT "(C) 2020-2024 OpenVPN, Inc."
+static void ovpn_struct_free(struct net_device *net)
+{
+}
+
+static int ovpn_net_open(struct net_device *dev)
+{
+ netif_tx_start_all_queues(dev);
+ return 0;
+}
+
+static int ovpn_net_stop(struct net_device *dev)
+{
+ netif_tx_stop_all_queues(dev);
+ return 0;
+}
+
+static const struct net_device_ops ovpn_netdev_ops = {
+ .ndo_open = ovpn_net_open,
+ .ndo_stop = ovpn_net_stop,
+ .ndo_start_xmit = ovpn_net_xmit,
+};
+
+static const struct device_type ovpn_type = {
+ .name = OVPN_FAMILY_NAME,
+};
+
+static const struct nla_policy ovpn_policy[IFLA_OVPN_MAX + 1] = {
+ [IFLA_OVPN_MODE] = NLA_POLICY_RANGE(NLA_U8, OVPN_MODE_P2P,
+ OVPN_MODE_MP),
+};
+
/**
* ovpn_dev_is_valid - check if the netdevice is of type 'ovpn'
* @dev: the interface to check
@@ -33,16 +67,76 @@ bool ovpn_dev_is_valid(const struct net_device *dev)
return dev->netdev_ops->ndo_start_xmit == ovpn_net_xmit;
}
+static void ovpn_setup(struct net_device *dev)
+{
+ /* compute the overhead considering AEAD encryption */
+ const int overhead = sizeof(u32) + NONCE_WIRE_SIZE + 16 +
+ sizeof(struct udphdr) +
+ max(sizeof(struct ipv6hdr), sizeof(struct iphdr));
+
+ netdev_features_t feat = NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM |
+ NETIF_F_GSO | NETIF_F_GSO_SOFTWARE |
+ NETIF_F_HIGHDMA;
+
+ dev->needs_free_netdev = true;
+
+ dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
+
+ dev->netdev_ops = &ovpn_netdev_ops;
+
+ dev->priv_destructor = ovpn_struct_free;
+
+ dev->hard_header_len = 0;
+ dev->addr_len = 0;
+ dev->mtu = ETH_DATA_LEN - overhead;
+ dev->min_mtu = IPV4_MIN_MTU;
+ dev->max_mtu = IP_MAX_MTU - overhead;
+
+ dev->type = ARPHRD_NONE;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+ dev->priv_flags |= IFF_NO_QUEUE;
+
+ dev->lltx = true;
+ dev->features |= feat;
+ dev->hw_features |= feat;
+ dev->hw_enc_features |= feat;
+
+ dev->needed_headroom = OVPN_HEAD_ROOM;
+ dev->needed_tailroom = OVPN_MAX_PADDING;
+
+ SET_NETDEV_DEVTYPE(dev, &ovpn_type);
+}
+
static int ovpn_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
- return -EOPNOTSUPP;
+ struct ovpn_struct *ovpn = netdev_priv(dev);
+ enum ovpn_mode mode = OVPN_MODE_P2P;
+
+ if (data && data[IFLA_OVPN_MODE]) {
+ mode = nla_get_u8(data[IFLA_OVPN_MODE]);
Some sanity check perhaps? "validate" op is here for that purpose.
Isn't the parsing happening here enough
https://elixir.bootlin.com/linux/v6.12-rc3/source/net/core/rtnetlink.c#L3659
The IFINFO_DATA is parsed using the policy I provided (which comes with
limits for the mode attribute).
Or am I misreading the code and I still need to provide an
implementation for .validate?
Regards,
+ netdev_dbg(dev, "setting device mode: %u\n", mode);
+ }
+
+ ovpn->dev = dev;
+ ovpn->mode = mode;
+
+ /* turn carrier explicitly off after registration, this way state is
+ * clearly defined
+ */
+ netif_carrier_off(dev);
+
+ return register_netdevice(dev);
[...]
--
Antonio Quartulli
OpenVPN Inc.
