On 1/30/17 1:36 PM, Robert Shearman wrote:
> @@ -243,24 +245,29 @@ static bool mpls_egress(struct mpls_route *rt, struct
> sk_buff *skb,
> payload_type = ip_hdr(skb)->version;
>
> switch (payload_type) {
> - case MPT_IPV4: {
> - struct iphdr *hdr4 = ip_hdr(skb);
> - skb->protocol = htons(ETH_P_IP);
> - csum_replace2(&hdr4->check,
> - htons(hdr4->ttl << 8),
> - htons(dec.ttl << 8));
> - hdr4->ttl = dec.ttl;
> + case MPT_IPV4:
> + if (net->mpls.ip_ttl_propagate) {
> + struct iphdr *hdr4 = ip_hdr(skb);
> +
> + skb->protocol = htons(ETH_P_IP);
The protocol setting here and ...
> + csum_replace2(&hdr4->check,
> + htons(hdr4->ttl << 8),
> + htons(dec.ttl << 8));
> + hdr4->ttl = dec.ttl;
> + }
> success = true;
> break;
> - }
> - case MPT_IPV6: {
> - struct ipv6hdr *hdr6 = ipv6_hdr(skb);
> - skb->protocol = htons(ETH_P_IPV6);
> - hdr6->hop_limit = dec.ttl;
> + case MPT_IPV6:
> + if (net->mpls.ip_ttl_propagate) {
> + struct ipv6hdr *hdr6 = ipv6_hdr(skb);
> +
> + skb->protocol = htons(ETH_P_IPV6);
here need to be done outside of net->mpls.ip_ttl_propagate otherwise ...
> + hdr6->hop_limit = dec.ttl;
> + }
> success = true;
> break;
> - }
> case MPT_UNSPEC:
> + /* Should have decided which protocol it is by now */
> break;
> }
>
disabling ip_ttl_propagate causes a corrupted packet to show up at the end host
(after the LSP):
IP4:
16:54:08.895372 46:a9:1c:9f:30:ba > fa:61:57:d6:1a:7d, ethertype MPLS unicast
(0x8847), length 98: MPLS (label 282624, exp 0, ttl 84)
(label 433380, exp 0, ttl 0)
(label 262160, exp 7, [S], ttl 182)
0x0000: ac10 0101 0a0a 0a0a 0800 1677 05d3 0001 ...........w....
0x0010: 30e0 8f58 0000 0000 4fa9 0d00 0000 0000 0..X....O.......
0x0020: 1011 1213 1415 1617 1819 1a1b 1c1d 1e1f ................
0x0030: 2021 2223 2425 2627 2829 2a2b 2c2d 2e2f .!"#$%&'()*+,-./
0x0040: 3031 3233 3435 3637 01234567
IPv6:
16:57:40.517520 46:a9:1c:9f:30:ba > fa:61:57:d6:1a:7d, ethertype MPLS unicast
(0x8847), length 118: MPLS (label 393290, exp 5, ttl 240)
(label 1027, exp 5, ttl 64)
(label 131072, exp 0, ttl 1)
(label 0 (IPv4 explicit NULL), exp 0, ttl 0)
(label 0 (IPv4 explicit NULL), exp 0, ttl 0)
(label 0 (IPv4 explicit NULL), exp 0, ttl 1)
(label 196608, exp 0, ttl 1)
(label 0 (IPv4 explicit NULL), exp 0, ttl 0)
(label 0 (IPv4 explicit NULL), exp 0, ttl 0)
(label 0 (IPv4 explicit NULL), exp 0, ttl 1)
(label 524297, exp 1, [S], ttl 102)
0x0000: 0628 0001 04e1 8f58 0000 0000 3be5 0700 .(.....X....;...
0x0010: 0000 0000 1011 1213 1415 1617 1819 1a1b ................
0x0020: 1c1d 1e1f 2021 2223 2425 2627 2829 2a2b .....!"#$%&'()*+
0x0030: 2c2d 2e2f 3031 3233 3435 3637 ,-./01234567
