From 34c169c462cf48c80631f2ea0f29a5a7b578f2e5 Mon Sep 17 00:00:00 2001
From: Patrik Flykt <patrik.flykt@linux.intel.com>
Date: Thu, 4 Jan 2018 15:11:56 +0200
Subject: [PATCH] radv: Add function to remove prefixes

As DHCPv6 leases may expire at some point, the delegated prefixes
have to be removed. Add a prefix removal function to the Router
Advertisement handling code.
---
 src/libsystemd-network/sd-radv.c | 26 ++++++++++++++++++++++++++
 src/systemd/sd-radv.h            |  2 ++
 2 files changed, 28 insertions(+)

diff --git a/src/libsystemd-network/sd-radv.c b/src/libsystemd-network/sd-radv.c
index 169278d5e3..b2483bcf2b 100644
--- a/src/libsystemd-network/sd-radv.c
+++ b/src/libsystemd-network/sd-radv.c
@@ -621,6 +621,32 @@ _public_ int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, bool dynamic) {
         return 0;
 }
 
+_public_ sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra,
+                                               struct in6_addr *prefix,
+                                               uint8_t prefixlen) {
+        sd_radv_prefix *cur, *next;
+
+        assert_return(ra, NULL);
+        assert_return(prefix, NULL);
+
+        LIST_FOREACH_SAFE(prefix, cur, next, ra->prefixes) {
+                if (prefixlen != cur->opt.prefixlen)
+                        continue;
+
+                if (!in_addr_equal(AF_INET6,
+                                   (union in_addr_union *)prefix,
+                                   (union in_addr_union *)&cur->opt.in6_addr))
+                        continue;
+
+                LIST_REMOVE(prefix, ra->prefixes, cur);
+                ra->n_prefixes--;
+
+                break;
+        }
+
+        return cur;
+}
+
 _public_ int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
                                const struct in6_addr *dns, size_t n_dns) {
         _cleanup_free_ struct sd_radv_opt_dns *opt_rdnss = NULL;
diff --git a/src/systemd/sd-radv.h b/src/systemd/sd-radv.h
index 393c977bf1..e319a82dbf 100644
--- a/src/systemd/sd-radv.h
+++ b/src/systemd/sd-radv.h
@@ -64,6 +64,8 @@ int sd_radv_set_managed_information(sd_radv *ra, int managed);
 int sd_radv_set_other_information(sd_radv *ra, int other);
 int sd_radv_set_preference(sd_radv *ra, unsigned preference);
 int sd_radv_add_prefix(sd_radv *ra, sd_radv_prefix *p, bool dynamic);
+sd_radv_prefix *sd_radv_remove_prefix(sd_radv *ra, struct in6_addr *prefix,
+                                      uint8_t prefixlen);
 int sd_radv_set_rdnss(sd_radv *ra, uint32_t lifetime,
                       const struct in6_addr *dns, size_t n_dns);
 int sd_radv_set_dnssl(sd_radv *ra, uint32_t lifetime, char **search_list);