Commit 52d03786 authored by Justin Iurman's avatar Justin Iurman Committed by David S. Miller
Browse files

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: default avatarJustin Iurman <justin.iurman@uliege.be>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9ac93627

include/net/ioam6.h

+2 −1
Original line number Diff line number Diff line
@@ -56,7 +56,8 @@ static inline struct ioam6_pernet_data *ioam6_pernet(struct net *net) 
struct ioam6_namespace *ioam6_namespace(struct net *net, __be16 id);

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);



int ioam6_init(void);

void ioam6_exit(void);

net/ipv6/exthdrs.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

net/ipv6/ioam6.c

+6 −5
Original line number Diff line number Diff line
@@ -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;

}