Re: [ovs-dev] [PATCH v2 2/2] OVN: Add support for periodic router advertisements.

[Jakub Sitnicki]

On Fri, Nov 03, 2017 at 04:24 PM GMT, Mark Michelson wrote:
> Thanks for the reviews Jakub. I've added an in-line comment below.
> Otherwise consider that there is an implicit "Will do!" on all of your
> other suggestions.
>
> On Fri, Nov 3, 2017 at 11:04 AM Jakub Sitnicki  wrote:

[...]

>> > diff --git a/lib/packets.h b/lib/packets.h
>> > index 057935cbf..9d69b93d0 100644
>> > --- a/lib/packets.h
>> > +++ b/lib/packets.h
>> > @@ -976,6 +976,7 @@ BUILD_ASSERT_DECL(ND_PREFIX_OPT_LEN == sizeof(struct
>> ovs_nd_prefix_opt));
>> >
>> >  /* Neighbor Discovery option: MTU. */
>> >  #define ND_MTU_OPT_LEN 8
>> > +#define ND_MTU_DEFAULT 0
>> >  struct ovs_nd_mtu_opt {
>> >  uint8_t  type;  /* ND_OPT_MTU */
>> >  uint8_t  len;   /* Always 1. */
>> > @@ -1015,6 +1016,9 @@ BUILD_ASSERT_DECL(RA_MSG_LEN == sizeof(struct
>> ovs_ra_msg));
>> >  #define ND_RA_MANAGED_ADDRESS 0x80
>> >  #define ND_RA_OTHER_CONFIG0x40
>> >
>> > +#define ND_RA_MAX_INTERVAL_DEFAULT 600
>> > +#define ND_RA_MIN_INTERVAL_DEFAULT(max) (max) >= 9 ? (max) / 3 : (max)
>> * 3 / 4
>> > +
>>
>> I don't understand the formula. It generates a sequence that is not
>> always increasing but takes a dip when max == 9. What is the reasoning
>> behind it?
>>
>
> It's based on RFC 4861 section 6.2.1.
>
>   MinRtrAdvInterval
>  The minimum time allowed between sending
>  unsolicited multicast Router Advertisements from
>  the interface, in seconds.  MUST be no less than 3
>  seconds and no greater than .75 *
>  MaxRtrAdvInterval.
>
>  Default: 0.33 * MaxRtrAdvInterval If
>  MaxRtrAdvInterval >= 9 seconds; otherwise, the
>  Default is 0.75 * MaxRtrAdvInterval.
>
> Note that this is not the exact quote from the RFC. I have altered the
> default text to include the suggested change from Errata 3154. Does that
> explain the formula better?
>
> I can add the citation to the code so that it makes more sense for someone
> skimming the code.

OK, I see now where it came from. Thanks for explaining it.

Maybe a short reference will do?

/* RFC 4861 MinRtrAdvInterval, MaxRtrAdvInterval */

... so the reader has a hint where to look it up.

-Jakub
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Re: [ovs-dev] [PATCH v2 2/2] OVN: Add support for periodic router advertisements.

[Numan Siddique]

On Fri, Nov 3, 2017 at 9:54 PM, Mark Michelson  wrote:

> Thanks for the reviews Jakub. I've added an in-line comment below.
> Otherwise consider that there is an implicit "Will do!" on all of your
> other suggestions.
>
> On Fri, Nov 3, 2017 at 11:04 AM Jakub Sitnicki  wrote:
>
> > Hi again Mark,
> >
> > A batch of nit-picks/suggestions & a question that I've collected so far
> > when reading through this patch. Please apply as you see fit.
> >
> > On Thu, Nov 02, 2017 at 08:47 PM GMT, Mark Michelson wrote:
> > > This change adds three new options to the Northbound
> > > Logical_Router_Port's ipv6_ra_configs option:
> > >
> > > * send_periodic: If set to "true", then OVN will send periodic router
> > > advertisements out of this router port.
> > > * max_interval: The maximum amount of time to wait between sending
> > > periodic router advertisements.
> > > * min_interval: The minimum amount of time to wait between sending
> > > periodic router advertisements.
> > >
> > > When send_periodic is true, then IPv6 RA configs, as well as some layer
> > > 2 and layer 3 information about the router port, are copied to the
> > > southbound database. From there, ovn-controller can use this
> information
> > > to know when to send periodic RAs and what to send in them.
> > >
> > > Because periodic RAs originate from each ovn-controller, the new
> > > keep-local flag is set on the packet so that ports don't receive an
> > > overabundance of RAs.
> > >
> > > Signed-off-by: Mark Michelson 
> > > ---
> > >  lib/packets.h|   4 +
> > >  ovn/controller/pinctrl.c | 349
> > +++
> > >  ovn/northd/ovn-northd.c  |  65 +
> > >  ovn/ovn-nb.xml   |  19 +++
> > >  tests/ovn-northd.at  | 110 +++
> > >  tests/ovn.at | 150 
> > >  6 files changed, 697 insertions(+)
> > >
> > > diff --git a/lib/packets.h b/lib/packets.h
> > > index 057935cbf..9d69b93d0 100644
> > > --- a/lib/packets.h
> > > +++ b/lib/packets.h
> > > @@ -976,6 +976,7 @@ BUILD_ASSERT_DECL(ND_PREFIX_OPT_LEN ==
> sizeof(struct
> > ovs_nd_prefix_opt));
> > >
> > >  /* Neighbor Discovery option: MTU. */
> > >  #define ND_MTU_OPT_LEN 8
> > > +#define ND_MTU_DEFAULT 0
> > >  struct ovs_nd_mtu_opt {
> > >  uint8_t  type;  /* ND_OPT_MTU */
> > >  uint8_t  len;   /* Always 1. */
> > > @@ -1015,6 +1016,9 @@ BUILD_ASSERT_DECL(RA_MSG_LEN == sizeof(struct
> > ovs_ra_msg));
> > >  #define ND_RA_MANAGED_ADDRESS 0x80
> > >  #define ND_RA_OTHER_CONFIG0x40
> > >
> > > +#define ND_RA_MAX_INTERVAL_DEFAULT 600
> > > +#define ND_RA_MIN_INTERVAL_DEFAULT(max) (max) >= 9 ? (max) / 3 :
> (max)
> > * 3 / 4
> > > +
> >
> > I don't understand the formula. It generates a sequence that is not
> > always increasing but takes a dip when max == 9. What is the reasoning
> > behind it?
> >
>
> It's based on RFC 4861 section 6.2.1.
>
> It would be nice if you could mention RFC 4861 in the code comments.

Thanks
Numan


>   MinRtrAdvInterval
>  The minimum time allowed between sending
>  unsolicited multicast Router Advertisements from
>  the interface, in seconds.  MUST be no less than 3
>  seconds and no greater than .75 *
>  MaxRtrAdvInterval.
>
>  Default: 0.33 * MaxRtrAdvInterval If
>  MaxRtrAdvInterval >= 9 seconds; otherwise, the
>  Default is 0.75 * MaxRtrAdvInterval.
>
> Note that this is not the exact quote from the RFC. I have altered the
> default text to include the suggested change from Errata 3154. Does that
> explain the formula better?
>
> I can add the citation to the code so that it makes more sense for someone
> skimming the code.
>
>
> >
> > Also, you probably want to put the expression in parenthesis to avoid
> > surprises in evalution like: ND_RA_MIN_INTERVAL_DEFAULT(max)*1000.
> >
> > >  /*
> > >   * Use the same struct for MLD and MLD2, naming members as the defined
> > fields in
> > >   * in the corresponding version of the protocol, though they are
> > reserved in the
> > > diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c
> > > index 29b2dde0c..f97eba4d5 100644
> > > --- a/ovn/controller/pinctrl.c
> > > +++ b/ovn/controller/pinctrl.c
> > > @@ -48,6 +48,7 @@
> > >  #include "socket-util.h"
> > >  #include "timeval.h"
> > >  #include "vswitch-idl.h"
> > > +#include "lflow.h"
> > >
> > >  VLOG_DEFINE_THIS_MODULE(pinctrl);
> > >
> > > @@ -88,6 +89,11 @@ static void pinctrl_handle_put_nd_ra_opts(
> > >  static void pinctrl_handle_nd_ns(const struct flow *ip_flow,
> > >   const struct match *md,
> > >   struct ofpbuf *userdata);
> > > +static void init_ipv6_ras(void);
> > > +static void destroy_ipv6_ras(void);
> > > +static void ipv6_ra_wait(void);
> > 

Re: [ovs-dev] [PATCH v2 2/2] OVN: Add support for periodic router advertisements.

[Mark Michelson]

Thanks for the reviews Jakub. I've added an in-line comment below.
Otherwise consider that there is an implicit "Will do!" on all of your
other suggestions.

On Fri, Nov 3, 2017 at 11:04 AM Jakub Sitnicki  wrote:

> Hi again Mark,
>
> A batch of nit-picks/suggestions & a question that I've collected so far
> when reading through this patch. Please apply as you see fit.
>
> On Thu, Nov 02, 2017 at 08:47 PM GMT, Mark Michelson wrote:
> > This change adds three new options to the Northbound
> > Logical_Router_Port's ipv6_ra_configs option:
> >
> > * send_periodic: If set to "true", then OVN will send periodic router
> > advertisements out of this router port.
> > * max_interval: The maximum amount of time to wait between sending
> > periodic router advertisements.
> > * min_interval: The minimum amount of time to wait between sending
> > periodic router advertisements.
> >
> > When send_periodic is true, then IPv6 RA configs, as well as some layer
> > 2 and layer 3 information about the router port, are copied to the
> > southbound database. From there, ovn-controller can use this information
> > to know when to send periodic RAs and what to send in them.
> >
> > Because periodic RAs originate from each ovn-controller, the new
> > keep-local flag is set on the packet so that ports don't receive an
> > overabundance of RAs.
> >
> > Signed-off-by: Mark Michelson 
> > ---
> >  lib/packets.h|   4 +
> >  ovn/controller/pinctrl.c | 349
> +++
> >  ovn/northd/ovn-northd.c  |  65 +
> >  ovn/ovn-nb.xml   |  19 +++
> >  tests/ovn-northd.at  | 110 +++
> >  tests/ovn.at | 150 
> >  6 files changed, 697 insertions(+)
> >
> > diff --git a/lib/packets.h b/lib/packets.h
> > index 057935cbf..9d69b93d0 100644
> > --- a/lib/packets.h
> > +++ b/lib/packets.h
> > @@ -976,6 +976,7 @@ BUILD_ASSERT_DECL(ND_PREFIX_OPT_LEN == sizeof(struct
> ovs_nd_prefix_opt));
> >
> >  /* Neighbor Discovery option: MTU. */
> >  #define ND_MTU_OPT_LEN 8
> > +#define ND_MTU_DEFAULT 0
> >  struct ovs_nd_mtu_opt {
> >  uint8_t  type;  /* ND_OPT_MTU */
> >  uint8_t  len;   /* Always 1. */
> > @@ -1015,6 +1016,9 @@ BUILD_ASSERT_DECL(RA_MSG_LEN == sizeof(struct
> ovs_ra_msg));
> >  #define ND_RA_MANAGED_ADDRESS 0x80
> >  #define ND_RA_OTHER_CONFIG0x40
> >
> > +#define ND_RA_MAX_INTERVAL_DEFAULT 600
> > +#define ND_RA_MIN_INTERVAL_DEFAULT(max) (max) >= 9 ? (max) / 3 : (max)
> * 3 / 4
> > +
>
> I don't understand the formula. It generates a sequence that is not
> always increasing but takes a dip when max == 9. What is the reasoning
> behind it?
>

It's based on RFC 4861 section 6.2.1.

  MinRtrAdvInterval
 The minimum time allowed between sending
 unsolicited multicast Router Advertisements from
 the interface, in seconds.  MUST be no less than 3
 seconds and no greater than .75 *
 MaxRtrAdvInterval.

 Default: 0.33 * MaxRtrAdvInterval If
 MaxRtrAdvInterval >= 9 seconds; otherwise, the
 Default is 0.75 * MaxRtrAdvInterval.

Note that this is not the exact quote from the RFC. I have altered the
default text to include the suggested change from Errata 3154. Does that
explain the formula better?

I can add the citation to the code so that it makes more sense for someone
skimming the code.


>
> Also, you probably want to put the expression in parenthesis to avoid
> surprises in evalution like: ND_RA_MIN_INTERVAL_DEFAULT(max)*1000.
>
> >  /*
> >   * Use the same struct for MLD and MLD2, naming members as the defined
> fields in
> >   * in the corresponding version of the protocol, though they are
> reserved in the
> > diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c
> > index 29b2dde0c..f97eba4d5 100644
> > --- a/ovn/controller/pinctrl.c
> > +++ b/ovn/controller/pinctrl.c
> > @@ -48,6 +48,7 @@
> >  #include "socket-util.h"
> >  #include "timeval.h"
> >  #include "vswitch-idl.h"
> > +#include "lflow.h"
> >
> >  VLOG_DEFINE_THIS_MODULE(pinctrl);
> >
> > @@ -88,6 +89,11 @@ static void pinctrl_handle_put_nd_ra_opts(
> >  static void pinctrl_handle_nd_ns(const struct flow *ip_flow,
> >   const struct match *md,
> >   struct ofpbuf *userdata);
> > +static void init_ipv6_ras(void);
> > +static void destroy_ipv6_ras(void);
> > +static void ipv6_ra_wait(void);
> > +static void send_ipv6_ras(const struct controller_ctx *ctx,
> > +struct hmap *local_datapaths);
> >
> >  COVERAGE_DEFINE(pinctrl_drop_put_mac_binding);
> >
> > @@ -98,6 +104,7 @@ pinctrl_init(void)
> >  conn_seq_no = 0;
> >  init_put_mac_bindings();
> >  init_send_garps();
> > +init_ipv6_ras();
> >  }
> >
> >  static ovs_be32
> > @@ -1083,8 +1090,348 @@ pinctrl_run(struct 

Re: [ovs-dev] [PATCH v2 2/2] OVN: Add support for periodic router advertisements.

[Jakub Sitnicki]

Hi again Mark,

A batch of nit-picks/suggestions & a question that I've collected so far
when reading through this patch. Please apply as you see fit.

On Thu, Nov 02, 2017 at 08:47 PM GMT, Mark Michelson wrote:
> This change adds three new options to the Northbound
> Logical_Router_Port's ipv6_ra_configs option:
>
> * send_periodic: If set to "true", then OVN will send periodic router
> advertisements out of this router port.
> * max_interval: The maximum amount of time to wait between sending
> periodic router advertisements.
> * min_interval: The minimum amount of time to wait between sending
> periodic router advertisements.
>
> When send_periodic is true, then IPv6 RA configs, as well as some layer
> 2 and layer 3 information about the router port, are copied to the
> southbound database. From there, ovn-controller can use this information
> to know when to send periodic RAs and what to send in them.
>
> Because periodic RAs originate from each ovn-controller, the new
> keep-local flag is set on the packet so that ports don't receive an
> overabundance of RAs.
>
> Signed-off-by: Mark Michelson 
> ---
>  lib/packets.h|   4 +
>  ovn/controller/pinctrl.c | 349 
> +++
>  ovn/northd/ovn-northd.c  |  65 +
>  ovn/ovn-nb.xml   |  19 +++
>  tests/ovn-northd.at  | 110 +++
>  tests/ovn.at | 150 
>  6 files changed, 697 insertions(+)
>
> diff --git a/lib/packets.h b/lib/packets.h
> index 057935cbf..9d69b93d0 100644
> --- a/lib/packets.h
> +++ b/lib/packets.h
> @@ -976,6 +976,7 @@ BUILD_ASSERT_DECL(ND_PREFIX_OPT_LEN == sizeof(struct 
> ovs_nd_prefix_opt));
>
>  /* Neighbor Discovery option: MTU. */
>  #define ND_MTU_OPT_LEN 8
> +#define ND_MTU_DEFAULT 0
>  struct ovs_nd_mtu_opt {
>  uint8_t  type;  /* ND_OPT_MTU */
>  uint8_t  len;   /* Always 1. */
> @@ -1015,6 +1016,9 @@ BUILD_ASSERT_DECL(RA_MSG_LEN == sizeof(struct 
> ovs_ra_msg));
>  #define ND_RA_MANAGED_ADDRESS 0x80
>  #define ND_RA_OTHER_CONFIG0x40
>
> +#define ND_RA_MAX_INTERVAL_DEFAULT 600
> +#define ND_RA_MIN_INTERVAL_DEFAULT(max) (max) >= 9 ? (max) / 3 : (max) * 3 / 
> 4
> +

I don't understand the formula. It generates a sequence that is not
always increasing but takes a dip when max == 9. What is the reasoning
behind it?

Also, you probably want to put the expression in parenthesis to avoid
surprises in evalution like: ND_RA_MIN_INTERVAL_DEFAULT(max)*1000.

>  /*
>   * Use the same struct for MLD and MLD2, naming members as the defined 
> fields in
>   * in the corresponding version of the protocol, though they are reserved in 
> the
> diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c
> index 29b2dde0c..f97eba4d5 100644
> --- a/ovn/controller/pinctrl.c
> +++ b/ovn/controller/pinctrl.c
> @@ -48,6 +48,7 @@
>  #include "socket-util.h"
>  #include "timeval.h"
>  #include "vswitch-idl.h"
> +#include "lflow.h"
>
>  VLOG_DEFINE_THIS_MODULE(pinctrl);
>
> @@ -88,6 +89,11 @@ static void pinctrl_handle_put_nd_ra_opts(
>  static void pinctrl_handle_nd_ns(const struct flow *ip_flow,
>   const struct match *md,
>   struct ofpbuf *userdata);
> +static void init_ipv6_ras(void);
> +static void destroy_ipv6_ras(void);
> +static void ipv6_ra_wait(void);
> +static void send_ipv6_ras(const struct controller_ctx *ctx,
> +struct hmap *local_datapaths);
>
>  COVERAGE_DEFINE(pinctrl_drop_put_mac_binding);
>
> @@ -98,6 +104,7 @@ pinctrl_init(void)
>  conn_seq_no = 0;
>  init_put_mac_bindings();
>  init_send_garps();
> +init_ipv6_ras();
>  }
>
>  static ovs_be32
> @@ -1083,8 +1090,348 @@ pinctrl_run(struct controller_ctx *ctx,
>  run_put_mac_bindings(ctx);
>  send_garp_run(ctx, br_int, chassis, chassis_index, local_datapaths,
>active_tunnels);
> +send_ipv6_ras(ctx, local_datapaths);
>  }
>
> +/* Table of ipv6_ra_state structures, keyed on logical port name */
> +static struct shash ipv6_ras;
> +
> +/* Next IPV6 RA in seconds. */
> +static long long int send_ipv6_ra_time;
> +
> +struct ipv6_network_prefix {
> +struct in6_addr addr;
> +unsigned int prefix_len;
> +};
> +
> +struct ipv6_ra_config {
> +time_t min_interval;
> +time_t max_interval;
> +struct eth_addr eth_src;
> +struct eth_addr eth_dst;
> +struct in6_addr ipv6_src;
> +struct in6_addr ipv6_dst;
> +ovs_be32 mtu;
> +uint8_t mo_flags;

Maybe annotate? For example /* Managed/Other RA flags */

> +uint8_t la_flags;

Maybe annotate? For example /* SLLAO flags */

> +struct ipv6_network_prefix *prefixes;
> +int n_prefixes;
> +};
> +
> +struct ipv6_ra_state {
> +long long int next_announce;
> +struct ipv6_ra_config *config;
> +int64_t port_key;
> +int64_t metadata;
> +bool deleteme;
> +};
> +
> +static void
> +init_ipv6_ras(void)
> +{
> +shash_init(_ras);
> +

[ovs-dev] [PATCH v2 2/2] OVN: Add support for periodic router advertisements.

[Mark Michelson]

This change adds three new options to the Northbound
Logical_Router_Port's ipv6_ra_configs option:

* send_periodic: If set to "true", then OVN will send periodic router
advertisements out of this router port.
* max_interval: The maximum amount of time to wait between sending
periodic router advertisements.
* min_interval: The minimum amount of time to wait between sending
periodic router advertisements.

When send_periodic is true, then IPv6 RA configs, as well as some layer
2 and layer 3 information about the router port, are copied to the
southbound database. From there, ovn-controller can use this information
to know when to send periodic RAs and what to send in them.

Because periodic RAs originate from each ovn-controller, the new
keep-local flag is set on the packet so that ports don't receive an
overabundance of RAs.

Signed-off-by: Mark Michelson 
---
 lib/packets.h|   4 +
 ovn/controller/pinctrl.c | 349 +++
 ovn/northd/ovn-northd.c  |  65 +
 ovn/ovn-nb.xml   |  19 +++
 tests/ovn-northd.at  | 110 +++
 tests/ovn.at | 150 
 6 files changed, 697 insertions(+)

diff --git a/lib/packets.h b/lib/packets.h
index 057935cbf..9d69b93d0 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -976,6 +976,7 @@ BUILD_ASSERT_DECL(ND_PREFIX_OPT_LEN == sizeof(struct 
ovs_nd_prefix_opt));
 
 /* Neighbor Discovery option: MTU. */
 #define ND_MTU_OPT_LEN 8
+#define ND_MTU_DEFAULT 0
 struct ovs_nd_mtu_opt {
 uint8_t  type;  /* ND_OPT_MTU */
 uint8_t  len;   /* Always 1. */
@@ -1015,6 +1016,9 @@ BUILD_ASSERT_DECL(RA_MSG_LEN == sizeof(struct 
ovs_ra_msg));
 #define ND_RA_MANAGED_ADDRESS 0x80
 #define ND_RA_OTHER_CONFIG0x40
 
+#define ND_RA_MAX_INTERVAL_DEFAULT 600
+#define ND_RA_MIN_INTERVAL_DEFAULT(max) (max) >= 9 ? (max) / 3 : (max) * 3 / 4
+
 /*
  * Use the same struct for MLD and MLD2, naming members as the defined fields 
in
  * in the corresponding version of the protocol, though they are reserved in 
the
diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c
index 29b2dde0c..f97eba4d5 100644
--- a/ovn/controller/pinctrl.c
+++ b/ovn/controller/pinctrl.c
@@ -48,6 +48,7 @@
 #include "socket-util.h"
 #include "timeval.h"
 #include "vswitch-idl.h"
+#include "lflow.h"
 
 VLOG_DEFINE_THIS_MODULE(pinctrl);
 
@@ -88,6 +89,11 @@ static void pinctrl_handle_put_nd_ra_opts(
 static void pinctrl_handle_nd_ns(const struct flow *ip_flow,
  const struct match *md,
  struct ofpbuf *userdata);
+static void init_ipv6_ras(void);
+static void destroy_ipv6_ras(void);
+static void ipv6_ra_wait(void);
+static void send_ipv6_ras(const struct controller_ctx *ctx,
+struct hmap *local_datapaths);
 
 COVERAGE_DEFINE(pinctrl_drop_put_mac_binding);
 
@@ -98,6 +104,7 @@ pinctrl_init(void)
 conn_seq_no = 0;
 init_put_mac_bindings();
 init_send_garps();
+init_ipv6_ras();
 }
 
 static ovs_be32
@@ -1083,8 +1090,348 @@ pinctrl_run(struct controller_ctx *ctx,
 run_put_mac_bindings(ctx);
 send_garp_run(ctx, br_int, chassis, chassis_index, local_datapaths,
   active_tunnels);
+send_ipv6_ras(ctx, local_datapaths);
 }
 
+/* Table of ipv6_ra_state structures, keyed on logical port name */
+static struct shash ipv6_ras;
+
+/* Next IPV6 RA in seconds. */
+static long long int send_ipv6_ra_time;
+
+struct ipv6_network_prefix {
+struct in6_addr addr;
+unsigned int prefix_len;
+};
+
+struct ipv6_ra_config {
+time_t min_interval;
+time_t max_interval;
+struct eth_addr eth_src;
+struct eth_addr eth_dst;
+struct in6_addr ipv6_src;
+struct in6_addr ipv6_dst;
+ovs_be32 mtu;
+uint8_t mo_flags;
+uint8_t la_flags;
+struct ipv6_network_prefix *prefixes;
+int n_prefixes;
+};
+
+struct ipv6_ra_state {
+long long int next_announce;
+struct ipv6_ra_config *config;
+int64_t port_key;
+int64_t metadata;
+bool deleteme;
+};
+
+static void
+init_ipv6_ras(void)
+{
+shash_init(_ras);
+send_ipv6_ra_time = LLONG_MAX;
+}
+
+static void ipv6_ra_config_delete(struct ipv6_ra_config *config)
+{
+if (config) {
+free(config->prefixes);
+}
+free(config);
+}
+
+static void
+ipv6_ra_delete(struct ipv6_ra_state *ra)
+{
+ipv6_ra_config_delete(ra->config);
+free(ra);
+}
+
+static void
+destroy_ipv6_ras(void)
+{
+struct shash_node *iter, *next;
+SHASH_FOR_EACH_SAFE (iter, next, _ras) {
+struct ipv6_ra_state *ra = iter->data;
+ipv6_ra_delete(ra);
+shash_delete(_ras, iter);
+}
+shash_destroy(_ras);
+}
+
+static struct ipv6_ra_config *
+ipv6_ra_update_config(const struct sbrec_port_binding *pb)
+{
+struct ipv6_ra_config *config;
+
+config = xzalloc(sizeof *config);
+
+config->max_interval = smap_get_int(>options, "ipv6_ra_max_interval",
+