On Thu, Jan 24, 2019 at 9:46 AM Nazarov Sergey <s-nazarov@xxxxxxxxx> wrote:
> 22.01.2019, 20:48, "Paul Moore" <paul@xxxxxxxxxxxxxx>:
> >
> > Yes, exactly. If you don't pass the skb it shouldn't attempt to call
> > icmp_send() in case of error.
> >
> > --
> > paul moore
> > www.paul-moore.com
>
> You are right, sorry. We can do that without ip_options_compile modification.
> Simplified patch 2:
> ---
> net/ipv4/cipso_ipv4.c | 18 ++++++++++++++++--
> 1 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
> index 777fa3b..a4ed0a4 100644
> --- a/net/ipv4/cipso_ipv4.c
> +++ b/net/ipv4/cipso_ipv4.c
> @@ -1735,13 +1735,27 @@ int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
> */
> void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
> {
> + unsigned char optbuf[sizeof(struct ip_options) + 40];
> + struct ip_options *opt = (struct ip_options *)optbuf;
> +
> if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
> return;
>
> + /*
> + * We might be called above the IP layer,
> + * so we can not use icmp_send and IPCB here.
> + */
> +
> + memset(opt, 0, sizeof(struct ip_options));
> + opt->optlen = ip_hdr(skb)->ihl*4 - sizeof(struct iphdr);
Hmm, I think the above calculation should take into account the actual
length of the IP options, and not just the max size (calculate it
based on iphdr->ihl).
Beyond that fix, I think it's time to put together a proper patchset
and post it to the lists for formal review/merging.
Thanks for your work on this.
> + memcpy(opt->__data, (unsigned char *)&(ip_hdr(skb)[1]), opt->optlen);
> + if (ip_options_compile(dev_net(skb->dev), opt, NULL))
> + return;
> +
> if (gateway)
> - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
> + __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0, opt);
> else
> - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
> + __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0, opt);
> }
--
paul moore
www.paul-moore.com
