git: 4f3376951d70 - main - ipsec: Add PMTUD support for IPsec IPv4 over IPv6 tunnel

[Wojciech Macek]

The branch main has been updated by wma:

URL: https://cgit.FreeBSD.org/src/commit/?id=4f3376951d7024d1c3446af2260cef9e4d3404a6

commit 4f3376951d7024d1c3446af2260cef9e4d3404a6
Author:     Bartlomiej Grzesik <bag at semihalf.com>
AuthorDate: 2021-09-24 08:17:11 +0000
Commit:     Wojciech Macek <wma at FreeBSD.org>
CommitDate: 2021-09-24 08:17:11 +0000

    ipsec: Add PMTUD support for IPsec IPv4 over IPv6 tunnel
    
    Add support for checking PMTU for IPv4 packets encapsulated in IPv6 tunnels.
    
    Differential revision:  https://reviews.freebsd.org/D31769
    Sponsored by:           Stormshield
    Obtained from:          Semihalf
---
 sys/netipsec/ipsec_output.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/sys/netipsec/ipsec_output.c b/sys/netipsec/ipsec_output.c
index 2f8cc12c526b..50bbd72f0589 100644
--- a/sys/netipsec/ipsec_output.c
+++ b/sys/netipsec/ipsec_output.c
@@ -305,7 +305,6 @@ ipsec4_check_pmtu(struct mbuf *m, struct secpolicy *sp, int forwarding)
 	uint32_t idx;
 	int error;
 
-
 	/* Don't check PMTU if the frame won't have DF bit set. */
 	if (!V_ip4_ipsec_dfbit)
 		return (0);
@@ -335,15 +334,22 @@ setdf:
 	}
 
 	dst = &sav->sah->saidx.dst;
-
-	/* Final header is not ipv4. */
-	if (dst->sa.sa_family != AF_INET) {
+	memset(&inc, 0, sizeof(inc));
+	switch (dst->sa.sa_family) {
+	case AF_INET:
+		inc.inc_faddr = satosin(&dst->sa)->sin_addr;
+		break;
+#ifdef INET6
+	case AF_INET6:
+		inc.inc6_faddr = satosin6(&dst->sa)->sin6_addr;
+		inc.inc_flags |= INC_ISIPV6;
+		break;
+#endif
+	default:
 		key_freesav(&sav);
 		return (0);
 	}
 
-	memset(&inc, 0, sizeof(inc));
-	inc.inc_faddr = satosin(&dst->sa)->sin_addr;
 	key_freesav(&sav);
 	pmtu = tcp_hc_getmtu(&inc);
 	/* No entry in hostcache. */