Re: How do I publish default router preferences using rad?
I want to enable a scenario similar to what's described in
https://tools.ietf.org/html/rfc4191#section-5.1
I run local network services for which I want a stable, publicly routed
prefix, but my ISP's delegated prefix isn't static. I've setup a
Hurricane Electric IPv6 tunnel to get a static prefix along side the
dynamic, ISP-delegated prefix; https://github.com/cqcallaw/openbsd-router
has details.
Everything is functionally correct with the source-based routing
configuration described in the docs, but the HE tunnel is necessarily
slow because of the overhead incurred by the 6in4 tunnel. Connections
are faster if my multihomed hosts prefer the native route for traffic
that doesn't require use of the tunnel.
I had patched rad to experiment with route preferences as a solution to
this performance issue, but my local hosts don't seem to honor the
advertised route preferences. I'm still researching what's required on
the client side for route preferences to be honored.
On Sun, Aug 18, 2019 at 4:28 AM Florian Obser wrote:
> I'm curious, how are you using the router preference, could you tell
> us a bit more about your network topology?
> Also, what clients pay attention to it and how are they using it?
>
> Same goes for the route option, are you aware of clients using it?
>
> Thanks,
> Florian
>
> On Sat, Aug 17, 2019 at 08:09:54PM -0700, Caleb Callaway wrote:
> > If it interests anyone, I've also implemented the route option
> > described in https://tools.ietf.org/html/rfc4191#section-2.3
> >
> > I find sharing patches via this mailing list particularly unwieldy,
> > so I've pushed my work to a git branch at
> > https://github.com/cqcallaw/src/tree/rfc-4191
> >
> > On Wed, Aug 7, 2019 at 11:27 PM Caleb
> wrote:
> > >
> > > Thank you for the code and review! I've synthesized the existing patch
> > > and review into something that successfully advertises router
> > > preferences in local testing (verified w/ rdisc6). This patch does not
> > > implement the route information option specified in RFC 4191 section
> > > 2.3.
> > >
> > > diff --git a/usr.sbin/rad/frontend.c b/usr.sbin/rad/frontend.c
> > > index 8178b058629..4031da6b99d 100644
> > > --- a/usr.sbin/rad/frontend.c
> > > +++ b/usr.sbin/rad/frontend.c
> > > @@ -411,7 +411,7 @@ frontend_dispatch_main(int fd, short event, void
> *bula)
> > > ra_prefix_conf))
> > >fatalx("%s: IMSG_RECONF_RA_PREFIX wrong "
> > > "length: %lu", __func__,
> > > -IMSG_DATA_SIZE(imsg));
> > > +IMSG_DATA_SIZE(imsg));
> > >if ((ra_prefix_conf = malloc(sizeof(struct
> > > ra_prefix_conf))) == NULL)
> > >fatal(NULL);
> > > @@ -1023,6 +1023,18 @@ build_packet(struct ra_iface *ra_iface)
> > >ra->nd_ra_router_lifetime =
> > > htons(ra_options_conf->router_lifetime);
> > >}
> > > +
> > > + /* add router preference flags */
> > > + if (ra_options_conf->preference == ND_RA_FLAG_RTPREF_RSV) {
> > > + fatalx("Invalid router preference found during RA packet
> > > construction.");
> > > + }
> > > +
> > > + if (ra_options_conf->router_lifetime == 0) {
> > > + log_debug("Router lifetime set to zero; ignoring router
> > > preference per https://tools.ietf.org/html/rfc4191#section-2.2";);
> > > + } else {
> > > + ra->nd_ra_flags_reserved |= ra_options_conf->preference;
> > > + }
> > > +
> > >ra->nd_ra_reachable = htonl(ra_options_conf->reachable_time);
> > >ra->nd_ra_retransmit = htonl(ra_options_conf->retrans_timer);
> > >p += sizeof(*ra);
> > > diff --git a/usr.sbin/rad/parse.y b/usr.sbin/rad/parse.y
> > > index 004e5e22f92..74480148246 100644
> > > --- a/usr.sbin/rad/parse.y
> > > +++ b/usr.sbin/rad/parse.y
> > > @@ -32,6 +32,7 @@
> > > #include
> > > #include
> > > +#include
> > > #include
> > > #include
> > > @@ -117,10 +118,12 @@ typedef struct {
> > > %token CONFIGURATION OTHER LIFETIME REACHABLE TIME RETRANS TIMER
> > > %token AUTO PREFIX VALID PREFERRED LIFETIME ONLINK AUTONOMOUS
> > > %token ADDRESS_CONFIGURATION DNS NAMESERVER SEARCH MTU
> > > +%token PREFERENCE LOW MEDIUM HIGH
> > > %token STRING
> > > %token NUMBER
> > > %typeyesno
> > &g
Re: How do I publish default router preferences using rad?
If it interests anyone, I've also implemented the route option
described in https://tools.ietf.org/html/rfc4191#section-2.3
I find sharing patches via this mailing list particularly unwieldy,
so I've pushed my work to a git branch at
https://github.com/cqcallaw/src/tree/rfc-4191
On Wed, Aug 7, 2019 at 11:27 PM Caleb wrote:
>
> Thank you for the code and review! I've synthesized the existing patch
> and review into something that successfully advertises router
> preferences in local testing (verified w/ rdisc6). This patch does not
> implement the route information option specified in RFC 4191 section
> 2.3.
>
> diff --git a/usr.sbin/rad/frontend.c b/usr.sbin/rad/frontend.c
> index 8178b058629..4031da6b99d 100644
> --- a/usr.sbin/rad/frontend.c
> +++ b/usr.sbin/rad/frontend.c
> @@ -411,7 +411,7 @@ frontend_dispatch_main(int fd, short event, void *bula)
> ra_prefix_conf))
>fatalx("%s: IMSG_RECONF_RA_PREFIX wrong "
> "length: %lu", __func__,
> -IMSG_DATA_SIZE(imsg));
> +IMSG_DATA_SIZE(imsg));
>if ((ra_prefix_conf = malloc(sizeof(struct
> ra_prefix_conf))) == NULL)
>fatal(NULL);
> @@ -1023,6 +1023,18 @@ build_packet(struct ra_iface *ra_iface)
>ra->nd_ra_router_lifetime =
> htons(ra_options_conf->router_lifetime);
>}
> +
> + /* add router preference flags */
> + if (ra_options_conf->preference == ND_RA_FLAG_RTPREF_RSV) {
> + fatalx("Invalid router preference found during RA packet
> construction.");
> + }
> +
> + if (ra_options_conf->router_lifetime == 0) {
> + log_debug("Router lifetime set to zero; ignoring router
> preference per https://tools.ietf.org/html/rfc4191#section-2.2";);
> + } else {
> + ra->nd_ra_flags_reserved |= ra_options_conf->preference;
> + }
> +
>ra->nd_ra_reachable = htonl(ra_options_conf->reachable_time);
>ra->nd_ra_retransmit = htonl(ra_options_conf->retrans_timer);
>p += sizeof(*ra);
> diff --git a/usr.sbin/rad/parse.y b/usr.sbin/rad/parse.y
> index 004e5e22f92..74480148246 100644
> --- a/usr.sbin/rad/parse.y
> +++ b/usr.sbin/rad/parse.y
> @@ -32,6 +32,7 @@
> #include
> #include
> +#include
> #include
> #include
> @@ -117,10 +118,12 @@ typedef struct {
> %token CONFIGURATION OTHER LIFETIME REACHABLE TIME RETRANS TIMER
> %token AUTO PREFIX VALID PREFERRED LIFETIME ONLINK AUTONOMOUS
> %token ADDRESS_CONFIGURATION DNS NAMESERVER SEARCH MTU
> +%token PREFERENCE LOW MEDIUM HIGH
> %token STRING
> %token NUMBER
> %typeyesno
> +%typepreference
> %typestring
> %%
> @@ -166,6 +169,11 @@ yesno : YES { $$ = 1; }
>| NO{ $$ = 0; }
>;
> +preference : LOW { $$ = ND_RA_FLAG_RTPREF_LOW; }
> + | MEDIUM { $$ = ND_RA_FLAG_RTPREF_MEDIUM; }
> + | HIGH { $$ = ND_RA_FLAG_RTPREF_HIGH; }
> + ;
> +
> varset : STRING '=' string {
>char *s = $1;
>if (cmd_opts & OPT_VERBOSE)
> @@ -213,6 +221,9 @@ ra_opt_block: DEFAULT ROUTER yesno {
>| MTU NUMBER {
>ra_options->mtu = $2;
>}
> + | PREFERENCE preference {
> + ra_options->preference = $2;
> + }
>| DNS dns_block
>;
> @@ -426,16 +437,20 @@ lookup(char *s)
>{"default", DEFAULT},
>{"dns", DNS},
>{"hop", HOP},
> + {"high",HIGH},
>{"include", INCLUDE},
>{"interface", RA_IFACE},
>{"lifetime",LIFETIME},
>{"limit", LIMIT},
> + {"low", LOW},
>{"managed", MANAGED},
> + {"medium", MEDIUM},
>{"mtu", MTU},
>{"nameserver", NAMESERVER},
>{"no", NO},
>{"on-link", ONLINK},
>{"other", OTHER},
> + {"preference", PREFERENCE},
>{"preferred", PREFERRED},
>{"prefix", PREFIX},
>{"reachable", REACHABLE},
> diff --git a/usr.sbin/rad/printconf.c b/usr.sbin/rad/printconf.c
> index d42890da518..c2173d2142f 100644
> --- a/usr.sbin/rad/printconf.c
> +++ b/usr.sbin/rad/printconf.c
> @@ -26,6 +26,7 @@
> #include
> #include
> +#include
> #include
> #include
> @@ -34,6 +35,7 @@
> #include "rad.h"
> const char*yesno(int);
> +const char*preference(int);
> void print_ra_options(const char*, const struct ra_options_conf*);
> void print_prefix_options(const char*, const struct ra_prefix_conf*);
> @@ -42,6 +44,20 @@ yesno(int flag)
> {
>return flag ? "yes" : "no";
> }
> +const char*
> +preference(int p)
> +{
> + switch (p) {
> + case ND_RA_FLAG_RTPREF_LOW:
> + return "low";
> + case ND_RA_FLAG_RTPREF_MEDIUM:
> + return "medium";
> + case ND_RA_FLAG_RTPREF_HIGH:
> + return "high";
> + default:
> + return "invalid";
> + }
> +}
> void
> print_ra_options(const char *indent, const struct ra_options_conf *ra
