On Fri, Jul 20, 2018 at 03:40:07PM +0200, Björn Ketelaars wrote:
> New diff, which addresses all your comments except the "no mtu" bit in
> the parser as I do not understand what you mean.
Never mind then :)
I was thinking about something like this:
----8<----
mtu 1480
interface ix0 # gets mtu 1480 option from global default
interface em0 {
no mtu # do not send mtu option
}
----8<----
but that seems rather obscure. And can be achieved like this:
interface em0 { mtu 0 }
one tweak inline:
>
>
> diff --git frontend.c frontend.c
> index b06fa43038c..0509d2b3efe 100644
> --- frontend.c
> +++ frontend.c
> @@ -887,6 +887,7 @@ void
> build_packet(struct ra_iface *ra_iface)
> {
> struct nd_router_advert *ra;
> + struct nd_opt_mtu *ndopt_mtu;
> struct nd_opt_prefix_info *ndopt_pi;
> struct ra_iface_conf *ra_iface_conf;
> struct ra_options_conf *ra_options_conf;
> @@ -904,6 +905,8 @@ build_packet(struct ra_iface *ra_iface)
> ra_options_conf = &ra_iface_conf->ra_options;
>
> len = sizeof(*ra);
> + if (ra_options_conf->mtu > 0)
> + len += sizeof(*ndopt_mtu);
> len += sizeof(*ndopt_pi) * ra_iface->prefix_count;
> if (ra_iface_conf->rdnss_count > 0)
> len += sizeof(*ndopt_rdnss) + ra_iface_conf->rdnss_count *
> @@ -940,6 +943,15 @@ build_packet(struct ra_iface *ra_iface)
> ra->nd_ra_retransmit = htonl(ra_options_conf->retrans_timer);
> p += sizeof(*ra);
>
> + if (ra_options_conf->mtu > 0) {
> + ndopt_mtu = (struct nd_opt_mtu *)p;
> + ndopt_mtu->nd_opt_mtu_type = ND_OPT_MTU;
> + ndopt_mtu->nd_opt_mtu_len = 1;
> + ndopt_mtu->nd_opt_mtu_reserved = 0;
> + ndopt_mtu->nd_opt_mtu_mtu = htonl(ra_options_conf->mtu);
> + p += sizeof(*ndopt_mtu);
> + }
> +
> SIMPLEQ_FOREACH(ra_prefix_conf, &ra_iface->prefixes, entry) {
> ndopt_pi = (struct nd_opt_prefix_info *)p;
> memset(ndopt_pi, 0, sizeof(*ndopt_pi));
> diff --git parse.y parse.y
> index 582d165c7d6..6eb6990f97b 100644
> --- parse.y
> +++ parse.y
> @@ -115,7 +115,7 @@ typedef struct {
> %token DEFAULT ROUTER HOP LIMIT MANAGED ADDRESS
> %token CONFIGURATION OTHER LIFETIME REACHABLE TIME RETRANS TIMER
> %token AUTO PREFIX VALID PREFERRED LIFETIME ONLINK AUTONOMOUS
> -%token ADDRESS_CONFIGURATION DNS RESOLVER SEARCH
> +%token ADDRESS_CONFIGURATION DNS RESOLVER SEARCH MTU
>
> %token <v.string> STRING
> %token <v.number> NUMBER
> @@ -209,6 +209,9 @@ ra_opt_block : DEFAULT ROUTER yesno {
> | RETRANS TIMER NUMBER {
> ra_options->retrans_timer = $3;
> }
> + | MTU NUMBER {
> + ra_options->mtu = $2;
> + }
> ;
>
> optnl : '\n' optnl /* zero or more newlines */
> @@ -423,6 +426,7 @@ lookup(char *s)
> {"lifetime", LIFETIME},
> {"limit", LIMIT},
> {"managed", MANAGED},
> + {"mtu", MTU},
> {"no", NO},
> {"on-link", ONLINK},
> {"other", OTHER},
> diff --git printconf.c printconf.c
> index 1fc8cd4ca3f..b7864dbae6b 100644
> --- printconf.c
> +++ printconf.c
> @@ -54,6 +54,7 @@ print_ra_options(const char *indent, const struct
> ra_options_conf *ra_options)
> printf("%srouter lifetime %d\n", indent, ra_options->router_lifetime);
> printf("%sreachable time %u\n", indent, ra_options->reachable_time);
> printf("%sretrans timer %u\n", indent, ra_options->retrans_timer);
please add
if (ra_options->mtu)
to print mtu only when it's set. Since mtu 0 means to not send the option at
all.
With that OK florian@
(note that I just caused a conflict for you in parse.y, sorry about that)
> + printf("%smtu %u\n", indent, ra_options->mtu);
> }
>
> void
> diff --git rad.c rad.c
> index 4652e1e0fb7..9f4be1b2190 100644
> --- rad.c
> +++ rad.c
> @@ -716,6 +716,7 @@ config_new_empty(void)
> xconf->ra_options.router_lifetime = 1800;
> xconf->ra_options.reachable_time = 0;
> xconf->ra_options.retrans_timer = 0;
> + xconf->ra_options.mtu = 0;
>
> return (xconf);
> }
> diff --git rad.conf.5 rad.conf.5
> index 6ca6b3ef956..486bec24769 100644
> --- rad.conf.5
> +++ rad.conf.5
> @@ -87,6 +87,11 @@ The default is 1800 seconds.
> .\" XXX
> .\" .It Ic retrans timer Ar number
> .\" XXX
> +.It Ic mtu Ar bytes
> +The MTU option is used in Router Advertisement messages to ensure that all
> +nodes on a link use the same MTU value in those cases where the link MTU
> +is not well known.
> +The default is 0, meaning unspecified by this router.
> .El
> .Sh INTERFACES
> A list of interfaces to send advertisments on:
> diff --git rad.h rad.h
> index db80d7c772d..f9d26d66c9c 100644
> --- rad.h
> +++ rad.h
> @@ -76,7 +76,7 @@ enum imsg_type {
> IMSG_SOCKET_IPC
> };
>
> -/* RFC 4861 Section 4.2 */
> +/* RFC 4861 Sections 4.2 and 4.6.4 */
> struct ra_options_conf {
> int dfr; /* is default router? */
> int cur_hl; /* current hop limit */
> @@ -85,6 +85,7 @@ struct ra_options_conf {
> int router_lifetime; /* default router lifetime */
> uint32_t reachable_time;
> uint32_t retrans_timer;
> + uint32_t mtu;
> };
>
> /* RFC 4861 Section 4.6.2 */
--
I'm not entirely sure you are real.
