[PATCH net-next 1/5] ipv6: icmp: add a force_saddr param to icmp6_send()

[Eric Dumazet]

SIT or GRE tunnels might want to translate an IPV4 address
into a v4mapped one when translating ICMP to ICMPv6.

This patch adds the parameter to icmp6_send() but
does not change icmpv6_send() signature.

Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 include/linux/icmpv6.h | 3 ++-
 net/ipv6/icmp.c        | 7 +++++--
 net/ipv6/ip6_icmp.c    | 2 +-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/icmpv6.h b/include/linux/icmpv6.h
index 630f45335c73..432611a297fb 100644
--- a/include/linux/icmpv6.h
+++ b/include/linux/icmpv6.h
@@ -14,7 +14,8 @@ static inline struct icmp6hdr *icmp6_hdr(const struct sk_buff 
*skb)
 #if IS_ENABLED(CONFIG_IPV6)
 extern void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info);
 
-typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 
info);
+typedef void ip6_icmp_send_t(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+                            const struct in6_addr *force_saddr);
 extern int inet6_register_icmp_sender(ip6_icmp_send_t *fn);
 extern int inet6_unregister_icmp_sender(ip6_icmp_send_t *fn);
 
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index e32a72fb9982..6c57e6e90301 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -388,7 +388,8 @@ relookup_failed:
 /*
  *     Send an ICMP message in response to a packet in error
  */
-static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
+static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+                      const struct in6_addr *force_saddr)
 {
        struct net *net = dev_net(skb->dev);
        struct inet6_dev *idev = NULL;
@@ -475,6 +476,8 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 
code, __u32 info)
        memset(&fl6, 0, sizeof(fl6));
        fl6.flowi6_proto = IPPROTO_ICMPV6;
        fl6.daddr = hdr->saddr;
+       if (force_saddr)
+               saddr = force_saddr;
        if (saddr)
                fl6.saddr = *saddr;
        fl6.flowi6_mark = mark;
@@ -551,7 +554,7 @@ out:
  */
 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 {
-       icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
+       icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
        kfree_skb(skb);
 }
 
diff --git a/net/ipv6/ip6_icmp.c b/net/ipv6/ip6_icmp.c
index 14dacc544c3e..713676f14a0e 100644
--- a/net/ipv6/ip6_icmp.c
+++ b/net/ipv6/ip6_icmp.c
@@ -39,7 +39,7 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 
info)
 
        if (!send)
                goto out;
-       send(skb, type, code, info);
+       send(skb, type, code, info, NULL);
 out:
        rcu_read_unlock();
 }
-- 
2.8.0.rc3.226.g39d4020