[ovs-dev] [PATCH ovn] Add RDNSS support to OVN

Lorenzo Bianconi lorenzo.bianconi at redhat.com
Fri Oct 18 11:09:48 UTC 2019


Introduce the possibility to specify a RDNSS option to Router
Advertisement packets. DNS IPv6 address can be specified using
'rdnss' tag in the ipv6_ra_configs column of logical router
port table

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
---
 controller/pinctrl.c | 50 ++++++++++++++++++++++++++++++++++++++++++++
 northd/ovn-northd.c  |  5 +++++
 ovn-nb.xml           |  4 ++++
 tests/ovn.at         | 27 +++++++++++++++++-------
 4 files changed, 78 insertions(+), 8 deletions(-)

diff --git a/controller/pinctrl.c b/controller/pinctrl.c
index d826da186..5bc4b35e7 100644
--- a/controller/pinctrl.c
+++ b/controller/pinctrl.c
@@ -2192,6 +2192,8 @@ struct ipv6_ra_config {
     uint8_t mo_flags; /* Managed/Other flags for RAs */
     uint8_t la_flags; /* On-link/autonomous flags for address prefixes */
     struct lport_addresses prefixes;
+    struct in6_addr rdnss;
+    bool has_rdnss;
 };
 
 struct ipv6_ra_state {
@@ -2202,6 +2204,16 @@ struct ipv6_ra_state {
     bool delete_me;
 };
 
+#define ND_RDNSS_OPT_LEN    8
+#define ND_OPT_RDNSS        25
+struct nd_rdnss_opt {
+    uint8_t type;         /* ND_OPT_RDNSS. */
+    uint8_t len;          /* >= 3. */
+    ovs_be16 reserved;    /* Always 0. */
+    ovs_be32 lifetime;
+    const ovs_be128 dns[0];
+};
+
 static void
 init_ipv6_ras(void)
 {
@@ -2289,6 +2301,12 @@ ipv6_ra_update_config(const struct sbrec_port_binding *pb)
         VLOG_WARN("Invalid IP source %s", ip_addr);
         goto fail;
     }
+    const char *rdnss = smap_get(&pb->options, "ipv6_ra_rdnss");
+    if (rdnss && !ipv6_parse(rdnss, &config->rdnss)) {
+        VLOG_WARN("Invalid RDNSS source %s", rdnss);
+        goto fail;
+    }
+    config->has_rdnss = !!rdnss;
 
     return config;
 
@@ -2319,6 +2337,35 @@ put_load(uint64_t value, enum mf_field_id dst, int ofs, int n_bits,
     bitwise_one(ofpact_set_field_mask(sf), sf->field->n_bytes, ofs, n_bits);
 }
 
+static void
+packet_put_ra_rdnss_opt(struct dp_packet *b, uint8_t num,
+                        ovs_be32 lifetime, const struct in6_addr *dns)
+{
+    size_t prev_l4_size = dp_packet_l4_size(b);
+    struct ip6_hdr *nh = dp_packet_l3(b);
+    size_t len = 2 * num + 1;
+    size_t size = len * 8;
+
+    nh->ip6_plen = htons(prev_l4_size + len * 8);
+
+    struct nd_rdnss_opt *nd_rdnss = dp_packet_put_uninit(b, size);
+    nd_rdnss->type = ND_OPT_RDNSS;
+    nd_rdnss->len = len;
+    nd_rdnss->reserved = 0;
+    nd_rdnss->lifetime = lifetime;
+
+    ovs_be128 *addr = (ovs_be128 *)(nd_rdnss + 1);
+    for (int i = 0; i < num; i++) {
+        memcpy(addr + i, dns, sizeof(ovs_be32[4]));
+    }
+
+    struct ovs_ra_msg *ra = dp_packet_l4(b);
+    ra->icmph.icmp6_cksum = 0;
+    uint32_t icmp_csum = packet_csum_pseudoheader6(dp_packet_l3(b));
+    ra->icmph.icmp6_cksum = csum_finish(csum_continue(icmp_csum, ra,
+                                                      prev_l4_size + size));
+}
+
 /* Called with in the pinctrl_handler thread context. */
 static long long int
 ipv6_ra_send(struct rconn *swconn, struct ipv6_ra_state *ra)
@@ -2343,6 +2390,9 @@ ipv6_ra_send(struct rconn *swconn, struct ipv6_ra_state *ra)
             ra->config->la_flags, htonl(IPV6_ND_RA_OPT_PREFIX_VALID_LIFETIME),
             htonl(IPV6_ND_RA_OPT_PREFIX_PREFERRED_LIFETIME), addr);
     }
+    if (ra->config->has_rdnss) {
+        packet_put_ra_rdnss_opt(&packet, 1, 0xffffffff, &ra->config->rdnss);
+    }
 
     uint64_t ofpacts_stub[4096 / 8];
     struct ofpbuf ofpacts = OFPBUF_STUB_INITIALIZER(ofpacts_stub);
diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
index ea8ad7c2d..d1de36e08 100644
--- a/northd/ovn-northd.c
+++ b/northd/ovn-northd.c
@@ -6485,6 +6485,11 @@ copy_ra_to_sb(struct ovn_port *op, const char *address_mode)
     smap_add(&options, "ipv6_ra_prefixes", ds_cstr(&s));
     ds_destroy(&s);
 
+    const char *rdnss = smap_get(&op->nbrp->ipv6_ra_configs, "rdnss");
+    if (rdnss) {
+        smap_add(&options, "ipv6_ra_rdnss", rdnss);
+    }
+
     smap_add(&options, "ipv6_ra_src_eth", op->lrp_networks.ea_s);
 
     sbrec_port_binding_set_options(op->sb, &options);
diff --git a/ovn-nb.xml b/ovn-nb.xml
index 1504f8fca..f1f9b969e 100644
--- a/ovn-nb.xml
+++ b/ovn-nb.xml
@@ -1885,6 +1885,10 @@
         is one-third of <ref column="ipv6_ra_configs" key="max_interval"/>,
         i.e. 200 seconds if that key is unset.
       </column>
+
+      <column name="ipv6_ra_configs" key="rdnss">
+        IPv6 address of RDNSS server announced in RA packets
+      </column>
     </group>
 
     <group title="Options">
diff --git a/tests/ovn.at b/tests/ovn.at
index 6bdb9e8ed..80d38ea4c 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -12537,14 +12537,15 @@ construct_expected_ra() {
 
     local mtu=$1
     local ra_mo=$2
-    local ra_prefix_la=$3
+    local rdnss=$3
+    local ra_prefix_la=$4
 
     local slla=0101${src_mac}
     local mtu_opt=""
     if test $mtu != 0; then
         mtu_opt=05010000${mtu}
     fi
-    shift 3
+    shift 4
 
     local prefix=""
     while [[ $# -gt 0 ]] ; do
@@ -12554,7 +12555,12 @@ construct_expected_ra() {
         shift 2
     done
 
-    local ra=ff${ra_mo}ffff0000000000000000${slla}${mtu_opt}${prefix}
+    local rdnss_opt=""
+    if test $rdnss != 0; then
+        rdnss_opt=19030000ffffffff${rdnss}
+    fi
+
+    local ra=ff${ra_mo}ffff0000000000000000${slla}${mtu_opt}${prefix}${rdnss_opt}
     local icmp=8600XXXX${ra}
 
     local ip_len=$(expr ${#icmp} / 2)
@@ -12589,23 +12595,28 @@ ra_test() {
 }
 
 # Baseline test with no MTU
-ra_test 0 00 c0 40 aef00000000000000000000000000000
+ra_test 0 00 0 c0 40 aef00000000000000000000000000000
 
 # Now make sure an MTU option makes it
 ovn-nbctl --wait=hv set Logical_Router_Port ro-sw ipv6_ra_configs:mtu=1500
-ra_test 000005dc 00 c0 40 aef00000000000000000000000000000
+ra_test 000005dc 00 0 c0 40 aef00000000000000000000000000000
 
 # Now test for multiple network prefixes
 ovn-nbctl --wait=hv set Logical_Router_port ro-sw networks='aef0\:\:1/64 fd0f\:\:1/48'
-ra_test 000005dc 00 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
+ra_test 000005dc 00 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
+
+# Now test for RDNSS
+ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:rdnss='aef0::11'
+dns_addr=aef00000000000000000000000000011
+ra_test 000005dc 00 $dns_addr c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
 
 # Test a different address mode now
 ovn-nbctl --wait=hv set Logical_Router_Port ro-sw ipv6_ra_configs:address_mode=dhcpv6_stateful
-ra_test 000005dc 80 80 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
+ra_test 000005dc 80 $dns_addr 80 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
 
 # And the other address mode
 ovn-nbctl --wait=hv set Logical_Router_Port ro-sw ipv6_ra_configs:address_mode=dhcpv6_stateless
-ra_test 000005dc 40 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
+ra_test 000005dc 40 $dns_addr c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
 
 OVN_CLEANUP([hv1],[hv2])
 AT_CLEANUP
-- 
2.21.0



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