From 52d03786459a7cf4d63a68146409f7a2088aefb2 Mon Sep 17 00:00:00 2001 From: Justin Iurman Date: Sun, 3 Oct 2021 20:45:36 +0200 Subject: ipv6: ioam: Distinguish input and output for hop-limit This patch anticipates the support for the IOAM insertion inside in-transit packets, by making a difference between input and output in order to determine the right value for its hop-limit (inherited from the IPv6 hop-limit). Input case: happens before ip6_forward, the IPv6 hop-limit is not decremented yet -> decrement the IOAM hop-limit to reflect the new hop inside the trace. Output case: happens after ip6_forward, the IPv6 hop-limit has already been decremented -> keep the same value for the IOAM hop-limit. Signed-off-by: Justin Iurman Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 2 +- net/ipv6/ioam6.c | 11 ++++++----- 2 files changed, 7 insertions(+), 6 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 3a871a09f962..38ece3b7b839 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -979,7 +979,7 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) if (!skb_valid_dst(skb)) ip6_route_input(skb); - ioam6_fill_trace_data(skb, ns, trace); + ioam6_fill_trace_data(skb, ns, trace, true); break; default: break; diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c index 5e8961004832..4e5583dbadac 100644 --- a/net/ipv6/ioam6.c +++ b/net/ipv6/ioam6.c @@ -631,7 +631,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, struct ioam6_namespace *ns, struct ioam6_trace_hdr *trace, struct ioam6_schema *sc, - u8 sclen) + u8 sclen, bool is_input) { struct __kernel_sock_timeval ts; u64 raw64; @@ -645,7 +645,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, /* hop_lim and node_id */ if (trace->type.bit0) { byte = ipv6_hdr(skb)->hop_limit; - if (skb->dev) + if (is_input) byte--; raw32 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id; @@ -730,7 +730,7 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, /* hop_lim and node_id (wide) */ if (trace->type.bit8) { byte = ipv6_hdr(skb)->hop_limit; - if (skb->dev) + if (is_input) byte--; raw64 = dev_net(skb_dst(skb)->dev)->ipv6.sysctl.ioam6_id_wide; @@ -786,7 +786,8 @@ static void __ioam6_fill_trace_data(struct sk_buff *skb, /* called with rcu_read_lock() */ void ioam6_fill_trace_data(struct sk_buff *skb, struct ioam6_namespace *ns, - struct ioam6_trace_hdr *trace) + struct ioam6_trace_hdr *trace, + bool is_input) { struct ioam6_schema *sc; u8 sclen = 0; @@ -822,7 +823,7 @@ void ioam6_fill_trace_data(struct sk_buff *skb, return; } - __ioam6_fill_trace_data(skb, ns, trace, sc, sclen); + __ioam6_fill_trace_data(skb, ns, trace, sc, sclen, is_input); trace->remlen -= trace->nodelen + sclen; } -- cgit v1.2.3-59-g8ed1b