On 3/27/19 1:58 PM, Stephen Suryaputra wrote:
> Configuration check to accept source route IP options should be made on
> the incoming netdevice when the skb->dev is an l3mdev master. The route
> lookup for the source route next hop also needs the incoming netdev.
>
> Signed-off-by: Stephen Suryaputra <ssuryae...@gmail.com>
> ---
> net/ipv4/ip_input.c | 3 +++
> net/ipv4/ip_options.c | 6 +++++-
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
> index ecce2dc78f17..754176222ef6 100644
> --- a/net/ipv4/ip_input.c
> +++ b/net/ipv4/ip_input.c
> @@ -263,6 +263,9 @@ static inline bool ip_rcv_options(struct sk_buff *skb)
> const struct iphdr *iph;
> struct net_device *dev = skb->dev;
>
> + if (netif_is_l3_master(dev))
> + dev = __dev_get_by_index(dev_net(dev), IPCB(skb)->iif);
ip_rcv_options is called from ip_rcv_finish_core which already has this
dev. Passing it as an arg saves the lookup. I believe you can always use
dev as the input argument vs skb->dev.
> +
> /* It looks as overkill, because not all
> IP options require packet mangling.
> But it is the easiest for now, especially taking
> diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
> index 32a35043c9f5..99f37591d7c1 100644
> --- a/net/ipv4/ip_options.c
> +++ b/net/ipv4/ip_options.c
> @@ -620,6 +620,7 @@ int ip_options_rcv_srr(struct sk_buff *skb)
> struct iphdr *iph = ip_hdr(skb);
> unsigned char *optptr = skb_network_header(skb) + opt->srr;
> struct rtable *rt = skb_rtable(skb);
> + struct net_device *dev = skb->dev;
> struct rtable *rt2;
> unsigned long orefdst;
> int err;
> @@ -638,6 +639,9 @@ int ip_options_rcv_srr(struct sk_buff *skb)
> if (rt->rt_type != RTN_LOCAL)
> return -EINVAL;
>
> + if (netif_is_l3_master(dev))
> + dev = __dev_get_by_index(dev_net(dev), IPCB(skb)->iif);
same here - just pass net_device from ip_rcv_options
> +
> for (srrptr = optptr[2], srrspace = optptr[1]; srrptr <= srrspace;
> srrptr += 4) {
> if (srrptr + 3 > srrspace) {
> icmp_send(skb, ICMP_PARAMETERPROB, 0,
> htonl((opt->srr+2)<<24));
> @@ -647,7 +651,7 @@ int ip_options_rcv_srr(struct sk_buff *skb)
>
> orefdst = skb->_skb_refdst;
> skb_dst_set(skb, NULL);
> - err = ip_route_input(skb, nexthop, iph->saddr, iph->tos,
> skb->dev);
> + err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, dev);
> rt2 = skb_rtable(skb);
> if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type !=
> RTN_LOCAL)) {
> skb_dst_drop(skb);
>
