Re: [PATCH net-next v9 04/23] ovpn: add basic interface creation/destruction/management routines

Jiri Pirko
2024-10-16T08:27:30Z

Wed, Oct 16, 2024 at 03:03:04AM CEST, antonio@openvpn.net wrote:
>Add basic infrastructure for handling ovpn interfaces.
>
>Signed-off-by: Antonio Quartulli <antonio@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.

>+ 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); …