[ovs-dev] [PATCH v4 ovn 2/2] Add DNSSL support to OVN

Lorenzo Bianconi lorenzo.bianconi at redhat.com
Tue Oct 29 08:38:13 UTC 2019


> On Mon, Oct 28, 2019 at 8:10 PM Lorenzo Bianconi
> <lorenzo.bianconi at redhat.com> wrote:
> >
> > Introduce the possibility to specify a DNSSL option to Router
> > Advertisement packets. DNS Search list can be specified using
> > 'dnssl' 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 | 51 ++++++++++++++++++++++++++++++++++++++++++++
> >  lib/ovn-l7.h         | 11 ++++++++++
> >  northd/ovn-northd.c  |  4 ++++
> >  ovn-nb.xml           |  5 +++++
> >  tests/ovn.at         | 30 +++++++++++++++++---------
> >  5 files changed, 91 insertions(+), 10 deletions(-)
> >
> > diff --git a/controller/pinctrl.c b/controller/pinctrl.c
> > index f105ebb5c..0bd1ef3ef 100644
> > --- a/controller/pinctrl.c
> > +++ b/controller/pinctrl.c
> > @@ -2194,6 +2194,7 @@ struct ipv6_ra_config {
> >      struct lport_addresses prefixes;
> >      struct in6_addr rdnss;
> >      bool has_rdnss;
> > +    struct ds dnssl;
> >  };
> >
> >  struct ipv6_ra_state {
> > @@ -2215,6 +2216,7 @@ ipv6_ra_config_delete(struct ipv6_ra_config *config)
> >  {
> >      if (config) {
> >          destroy_lport_addresses(&config->prefixes);
> > +        ds_destroy(&config->dnssl);
> >          free(config);
> >      }
> >  }
> > @@ -2253,6 +2255,7 @@ ipv6_ra_update_config(const struct sbrec_port_binding *pb)
> >              nd_ra_min_interval_default(config->max_interval));
> >      config->mtu = smap_get_int(&pb->options, "ipv6_ra_mtu", ND_MTU_DEFAULT);
> >      config->la_flags = IPV6_ND_RA_OPT_PREFIX_ON_LINK;
> > +    ds_init(&config->dnssl);
> >
> >      const char *address_mode = smap_get(&pb->options, "ipv6_ra_address_mode");
> >      if (!address_mode) {
> > @@ -2298,6 +2301,11 @@ ipv6_ra_update_config(const struct sbrec_port_binding *pb)
> >      }
> >      config->has_rdnss = !!rdnss;
> >
> > +    const char *dnssl = smap_get(&pb->options, "ipv6_ra_dnssl");
> > +    if (dnssl) {
> > +        ds_put_buffer(&config->dnssl, dnssl, strlen(dnssl));
> > +    }
> > +
> >      return config;
> >
> >  fail:
> > @@ -2354,6 +2362,45 @@ packet_put_ra_rdnss_opt(struct dp_packet *b, uint8_t num,
> >                                                        prev_l4_size + len * 8));
> >  }
> >
> > +static void
> > +packet_put_ra_dnssl_opt(struct dp_packet *b, ovs_be32 lifetime,
> > +                        char *dnssl_list)
> > +{
> > +    char *t0, *r0 = dnssl_list, dnssl[255] = {};
> > +    size_t prev_l4_size = dp_packet_l4_size(b);
> > +    size_t size = sizeof(struct ovs_nd_dnssl);
> > +    struct ip6_hdr *nh = dp_packet_l3(b);
> > +    int i = 0;
> > +
> > +    while ((t0 = strtok_r(r0, ",", &r0))) {

Hi Numan,

thx for the review.

> 
> Are we not suppose to pass NULL as the first argument to subsequent
> calls of strtok_r ?
> 

right, will fix in v5

> Is there a chance that we might cross dnssl 255 length and have a segfault ?
> 

right, will fix in v5

> Can you please add comments on how the dnssl string is to be encoded ?
> 

ack, will add in v5

> Since the code here, is already handling for multiple dnssl values in
> the "dnssl_list", we can just accept
> multiple values of dnssl right ? Right now the patch is restricting to
> just 1 dnssl for the CMS to configure.

right.

Regards,
Lorenzo

> 
> Thanks
> Numan
> 
> 
> > +        char *t1, *r1 = t0;
> > +
> > +        size += strlen(t0) + 2;
> > +        while ((t1 = strtok_r(r1, ".", &r1))) {
> > +            dnssl[i++] = strlen(t1);
> > +            memcpy(&dnssl[i], t1, strlen(t1));
> > +            i += strlen(t1);
> > +        }
> > +        dnssl[i++] = 0;
> > +    }
> > +    size = ROUND_UP(size, 8);
> > +    nh->ip6_plen = htons(prev_l4_size + size);
> > +
> > +    struct ovs_nd_dnssl *nd_dnssl = dp_packet_put_uninit(b, sizeof *nd_dnssl);
> > +    nd_dnssl->type = ND_OPT_DNSSL;
> > +    nd_dnssl->len = size / 8;
> > +    nd_dnssl->reserved = 0;
> > +    put_16aligned_be32(&nd_dnssl->lifetime, lifetime);
> > +
> > +    dp_packet_put(b, dnssl, size - sizeof *nd_dnssl);
> > +
> > +    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)
> > @@ -2382,6 +2429,10 @@ ipv6_ra_send(struct rconn *swconn, struct ipv6_ra_state *ra)
> >          packet_put_ra_rdnss_opt(&packet, 1, htonl(0xffffffff),
> >                                  &ra->config->rdnss);
> >      }
> > +    if (ra->config->dnssl.length) {
> > +        packet_put_ra_dnssl_opt(&packet, htonl(0xffffffff),
> > +                                ra->config->dnssl.string);
> > +    }
> >
> >      uint64_t ofpacts_stub[4096 / 8];
> >      struct ofpbuf ofpacts = OFPBUF_STUB_INITIALIZER(ofpacts_stub);
> > diff --git a/lib/ovn-l7.h b/lib/ovn-l7.h
> > index 12cee6329..5fc370bf5 100644
> > --- a/lib/ovn-l7.h
> > +++ b/lib/ovn-l7.h
> > @@ -231,6 +231,17 @@ struct nd_rdnss_opt {
> >  };
> >  BUILD_ASSERT_DECL(ND_RDNSS_OPT_LEN == sizeof(struct nd_rdnss_opt));
> >
> > +/* DNSSL option RFC 6106 */
> > +#define ND_OPT_DNSSL        31
> > +#define ND_DNSSL_OPT_LEN    8
> > +struct ovs_nd_dnssl {
> > +    u_int8_t type;  /* ND_OPT_DNSSL */
> > +    u_int8_t len;   /* >= 2 */
> > +    ovs_be16 reserved;
> > +    ovs_16aligned_be32 lifetime;
> > +};
> > +BUILD_ASSERT_DECL(ND_DNSSL_OPT_LEN == sizeof(struct ovs_nd_dnssl));
> > +
> >  #define DHCPV6_DUID_LL      3
> >  #define DHCPV6_HW_TYPE_ETH  1
> >
> > diff --git a/northd/ovn-northd.c b/northd/ovn-northd.c
> > index d1de36e08..dbb279052 100644
> > --- a/northd/ovn-northd.c
> > +++ b/northd/ovn-northd.c
> > @@ -6489,6 +6489,10 @@ copy_ra_to_sb(struct ovn_port *op, const char *address_mode)
> >      if (rdnss) {
> >          smap_add(&options, "ipv6_ra_rdnss", rdnss);
> >      }
> > +    const char *dnssl = smap_get(&op->nbrp->ipv6_ra_configs, "dnssl");
> > +    if (dnssl) {
> > +        smap_add(&options, "ipv6_ra_dnssl", dnssl);
> > +    }
> >
> >      smap_add(&options, "ipv6_ra_src_eth", op->lrp_networks.ea_s);
> >
> > diff --git a/ovn-nb.xml b/ovn-nb.xml
> > index 2faf9390b..c49144848 100644
> > --- a/ovn-nb.xml
> > +++ b/ovn-nb.xml
> > @@ -1890,6 +1890,11 @@
> >          IPv6 address of RDNSS server announced in RA packets. At the moment
> >          OVN supports just one RDNSS server.
> >        </column>
> > +
> > +      <column name="ipv6_ra_configs" key="dnssl">
> > +        DNS Search List announced in RA packets. At the moment OVN supports
> > +        just one DNS Search entry
> > +      </column>
> >      </group>
> >
> >      <group title="Options">
> > diff --git a/tests/ovn.at b/tests/ovn.at
> > index 3e7692895..f4f5ddd5a 100644
> > --- a/tests/ovn.at
> > +++ b/tests/ovn.at
> > @@ -12538,14 +12538,15 @@ construct_expected_ra() {
> >      local mtu=$1
> >      local ra_mo=$2
> >      local rdnss=$3
> > -    local ra_prefix_la=$4
> > +    local dnssl=$4
> > +    local ra_prefix_la=$5
> >
> >      local slla=0101${src_mac}
> >      local mtu_opt=""
> >      if test $mtu != 0; then
> >          mtu_opt=05010000${mtu}
> >      fi
> > -    shift 4
> > +    shift 5
> >
> >      local prefix=""
> >      while [[ $# -gt 0 ]] ; do
> > @@ -12559,8 +12560,12 @@ construct_expected_ra() {
> >      if test $rdnss != 0; then
> >          rdnss_opt=19030000ffffffff${rdnss}
> >      fi
> > +    local dnssl_opt=""
> > +    if test $dnssl != 0; then
> > +        dnssl_opt=1f030000ffffffff${dnssl}
> > +    fi
> >
> > -    local ra=ff${ra_mo}ffff0000000000000000${slla}${mtu_opt}${prefix}${rdnss_opt}
> > +    local ra=ff${ra_mo}ffff0000000000000000${slla}${mtu_opt}${prefix}${rdnss_opt}${dnssl_opt}
> >      local icmp=8600XXXX${ra}
> >
> >      local ip_len=$(expr ${#icmp} / 2)
> > @@ -12595,28 +12600,33 @@ ra_test() {
> >  }
> >
> >  # Baseline test with no MTU
> > -ra_test 0 00 0 c0 40 aef00000000000000000000000000000
> > +ra_test 0 00 0 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 0 c0 40 aef00000000000000000000000000000
> > +ra_test 000005dc 00 0 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 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> > +ra_test 000005dc 00 0 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
> > +ra_test 000005dc 00 $dns_addr 0 c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> > +
> > +# Now test for DNSSL
> > +ovn-nbctl --wait=hv set Logical_Router_port ro-sw ipv6_ra_configs:dnssl="aa.bb.cc"
> > +dnssl=02616102626202636300000000000000
> > +ra_test 000005dc 00 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> >
> > -# Test a different address mode now
> > +## 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 $dns_addr 80 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> > +ra_test 000005dc 80 $dns_addr $dnssl 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 $dns_addr c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> > +ra_test 000005dc 40 $dns_addr $dnssl c0 40 aef00000000000000000000000000000 30 fd0f0000000000000000000000000000
> >
> >  OVN_CLEANUP([hv1],[hv2])
> >  AT_CLEANUP
> > --
> > 2.21.0
> >
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev


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