| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 6 Oct 2015 17:42:05 +0200
From: Jiri Benc <jbenc@...hat.com>
To: Pravin B Shelar <pshelar@...ira.com>
Cc: netdev@...r.kernel.org
Subject: Re: [PATCH net] openvswitch: Fix egress tunnel info.
Some more feedback after doing a deeper review.
On Mon, 5 Oct 2015 10:58:17 -0700, Pravin B Shelar wrote:
> --- a/drivers/net/geneve.c
> +++ b/drivers/net/geneve.c
> @@ -703,6 +703,32 @@ err:
> return NETDEV_TX_OK;
> }
>
> +static int geneve_egress_tun_info(struct net_device *dev, struct sk_buff *skb,
> + struct ip_tunnel_info *egress_tun_info,
> + const void **egress_tun_opts)
> +{
> + struct geneve_dev *geneve = netdev_priv(dev);
> + struct ip_tunnel_info *info;
> + struct rtable *rt;
> + struct flowi4 fl4;
> + __be16 sport;
> +
> + info = skb_tunnel_info(skb);
> + if (ip_tunnel_info_af(info) != AF_INET)
> + return -EINVAL;
> +
> + rt = geneve_get_rt(skb, dev, &fl4, info);
This will increase dev tx error stats in case the lookup fails which is
probably something we don't want.
[...]
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -60,6 +60,7 @@ struct wireless_dev;
> /* 802.15.4 specific */
> struct wpan_dev;
> struct mpls_dev;
> +struct ip_tunnel_info;
>
> void netdev_set_default_ethtool_ops(struct net_device *dev,
> const struct ethtool_ops *ops);
> @@ -1054,6 +1055,11 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
> * This function is used to pass protocol port error state information
> * to the switch driver. The switch driver can react to the proto_down
> * by doing a phys down on the associated switch port.
> + * int (*ndo_get_egress_info)(struct net_device *dev, struct sk_buff *skb,
> + * __be32 *saddr, __be16 *sport, __be16 *dport);
> + * This function is used to get egress tunnel information for given skb.
> + * This is useful for retrieving outer tunnel header parameters while
> + * sampling packet.
> *
> */
> struct net_device_ops {
> @@ -1227,6 +1233,10 @@ struct net_device_ops {
> int (*ndo_get_iflink)(const struct net_device *dev);
> int (*ndo_change_proto_down)(struct net_device *dev,
> bool proto_down);
> + int (*ndo_get_egress_info)(struct net_device *dev,
> + struct sk_buff *skb,
> + struct ip_tunnel_info *egress_tun_info,
> + const void **egress_tun_opts);
This should have at least a better name to reflect it is about IP
tunnels.
But I don't like having an IP tunnel specific ndo, that doesn't sound
right. The real thing that is wanted here is to complete the dst
metadata. What about:
int (*ndo_fill_metadata_dst)(struct net_device *dev, struct sk_buff *skb);
The function will use skb_tunnel_info to get the template info, then
skb_dst_drop and allocate and attach a fully populated metadata_dst.
The egress_tun_info in struct dp_upcall_info then can be completely
dropped, as all the necessary tunnel information will be available
through skb_tunnel_info(skb). Also, when implemented correctly, such
skb will be just sent out without route lookups etc. if afterwards
handed to ndo_start_xmit.
[...]
> --- a/include/net/ip_tunnels.h
> +++ b/include/net/ip_tunnels.h
> @@ -337,6 +337,11 @@ void __init ip_tunnel_core_init(void);
> void ip_tunnel_need_metadata(void);
> void ip_tunnel_unneed_metadata(void);
>
> +void ipv4_egress_info_init(struct ip_tunnel_info *egress_tun_info,
> + const void **egress_tun_opts,
> + struct ip_tunnel_info *info, __be32 saddr,
> + __be16 sport, __be16 dport);
Please use the ip_tunnel prefix as the rest of the functions, this is
not ipv4 egress info but ip *tunnel* egress info.
Also, it's not clear what the difference between "egress_tun_info" and
"info" is. I'd suggest to use "dst_info" and "src_info" or something
similar.
[...]
> --- a/net/ipv4/ip_tunnel_core.c
> +++ b/net/ipv4/ip_tunnel_core.c
> @@ -424,3 +424,40 @@ void ip_tunnel_unneed_metadata(void)
> static_key_slow_dec(&ip_tunnel_metadata_cnt);
> }
> EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
> +
> +static void tnl_egress_opts_init(struct ip_tunnel_info *egress_tun_info,
> + const void **egress_tun_opts,
> + struct ip_tunnel_info *info)
> +{
> + egress_tun_info->options_len = info->options_len;
> + egress_tun_info->mode = info->mode;
> +
> + /* Tunnel options. */
> + if (info->options_len)
> + *egress_tun_opts = ip_tunnel_info_opts(info);
> + else
> + *egress_tun_opts = NULL;
> +}
> +
> +void ipv4_egress_info_init(struct ip_tunnel_info *egress_tun_info,
> + const void **egress_tun_opts,
> + struct ip_tunnel_info *info, __be32 saddr,
> + __be16 sport, __be16 dport)
> +{
> + const struct ip_tunnel_key *tun_key;
> +
> + /* Generate egress_tun_info based on tun_info,
> + * saddr, tp_src and tp_dst
> + */
> + tun_key = &egress_tun_info->key;
> + ip_tunnel_key_init(&egress_tun_info->key,
Just pass tun_key as the first parameter, it will be clearer what's
going on. (I believe the assignments that have no effect will be
optimized out by the compiler, since ip_tunnel_key_init is an inline
function.)
> + saddr, tun_key->u.ipv4.dst,
> + tun_key->tos,
> + tun_key->ttl,
> + sport, dport,
> + tun_key->tun_id,
> + tun_key->tun_flags);
--
Jiri Benc
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists