RAdv: Allow solicited RAs to be sent as unicast

Add option to send solicited router advertisements as unicast directly
to soliciting nodes instead of as multicast to all-nodes group.
This commit is contained in:
Ondrej Zajicek (work) 2019-08-12 00:41:36 +02:00
parent 9f3e098320
commit 70a4320bdd
6 changed files with 72 additions and 27 deletions

View file

@ -4121,6 +4121,12 @@ definitions, prefix definitions and DNS definitions:
The minimum delay between two consecutive router advertisements, in The minimum delay between two consecutive router advertisements, in
seconds. Default: 3 seconds. Default: 3
<tag><label id="radv-solicited-ra-unicast">solicited ra unicast <m/switch/</tag>
Solicited router advertisements are usually sent to all-nodes multicast
group like unsolicited ones, but the router can be configured to send
them as unicast directly to soliciting nodes instead. This is especially
useful on wireless networks (see <rfc id="7772">). Default: no
<tag><label id="radv-iface-managed">managed <m/switch/</tag> <tag><label id="radv-iface-managed">managed <m/switch/</tag>
This option specifies whether hosts should use DHCPv6 for IP address This option specifies whether hosts should use DHCPv6 for IP address
configuration. Default: no configuration. Default: no

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@ -97,7 +97,7 @@ void sk_dump_all(void);
int sk_is_ipv4(sock *s); /* True if socket is IPv4 */ int sk_is_ipv4(sock *s); /* True if socket is IPv4 */
int sk_is_ipv6(sock *s); /* True if socket is IPv6 */ int sk_is_ipv6(sock *s); /* True if socket is IPv6 */
static inline int sk_send_buffer_empty(sock *sk) static inline int sk_tx_buffer_empty(sock *sk)
{ return sk->tbuf == sk->tpos; } { return sk->tbuf == sk->tpos; }
int sk_setup_multicast(sock *s); /* Prepare UDP or IP socket for multicasting */ int sk_setup_multicast(sock *s); /* Prepare UDP or IP socket for multicasting */

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@ -1,6 +1,8 @@
/* /*
* BIRD -- Router Advertisement Configuration * BIRD -- Router Advertisement Configuration
* *
* (c) 2011--2019 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2011--2019 CZ.NIC z.s.p.o.
* *
* Can be freely distributed and used under the terms of the GNU GPL. * Can be freely distributed and used under the terms of the GNU GPL.
*/ */
@ -26,12 +28,12 @@ static u8 radv_mult_val; /* Used by radv_mult for second return value */
CF_DECLS CF_DECLS
CF_KEYWORDS(RADV, PREFIX, INTERFACE, MIN, MAX, RA, DELAY, INTERVAL, CF_KEYWORDS(RADV, PREFIX, INTERFACE, MIN, MAX, RA, DELAY, INTERVAL, SOLICITED,
MANAGED, OTHER, CONFIG, LINGER, LINK, MTU, REACHABLE, TIME, RETRANS, UNICAST, MANAGED, OTHER, CONFIG, LINGER, LINK, MTU, REACHABLE, TIME,
TIMER, CURRENT, HOP, LIMIT, DEFAULT, VALID, PREFERRED, MULT, RETRANS, TIMER, CURRENT, HOP, LIMIT, DEFAULT, VALID, PREFERRED, MULT,
LIFETIME, SKIP, ONLINK, AUTONOMOUS, RDNSS, DNSSL, NS, DOMAIN, LIFETIME, SKIP, ONLINK, AUTONOMOUS, RDNSS, DNSSL, NS, DOMAIN, LOCAL,
LOCAL, TRIGGER, SENSITIVE, PREFERENCE, LOW, MEDIUM, HIGH, PROPAGATE, TRIGGER, SENSITIVE, PREFERENCE, LOW, MEDIUM, HIGH, PROPAGATE, ROUTE,
ROUTE, ROUTES, RA_PREFERENCE, RA_LIFETIME) ROUTES, RA_PREFERENCE, RA_LIFETIME)
CF_ENUM(T_ENUM_RA_PREFERENCE, RA_PREF_, LOW, MEDIUM, HIGH) CF_ENUM(T_ENUM_RA_PREFERENCE, RA_PREF_, LOW, MEDIUM, HIGH)
@ -98,6 +100,7 @@ radv_iface_item:
MIN RA INTERVAL expr { RADV_IFACE->min_ra_int = $4; if ($4 < 3) cf_error("Min RA interval must be at least 3"); } MIN RA INTERVAL expr { RADV_IFACE->min_ra_int = $4; if ($4 < 3) cf_error("Min RA interval must be at least 3"); }
| MAX RA INTERVAL expr { RADV_IFACE->max_ra_int = $4; if (($4 < 4) || ($4 > 1800)) cf_error("Max RA interval must be in range 4-1800"); } | MAX RA INTERVAL expr { RADV_IFACE->max_ra_int = $4; if (($4 < 4) || ($4 > 1800)) cf_error("Max RA interval must be in range 4-1800"); }
| MIN DELAY expr { RADV_IFACE->min_delay = $3; if ($3 <= 0) cf_error("Min delay must be positive"); } | MIN DELAY expr { RADV_IFACE->min_delay = $3; if ($3 <= 0) cf_error("Min delay must be positive"); }
| SOLICITED RA UNICAST bool { RADV_IFACE->solicited_ra_unicast = $4; }
| MANAGED bool { RADV_IFACE->managed = $2; } | MANAGED bool { RADV_IFACE->managed = $2; }
| OTHER CONFIG bool { RADV_IFACE->other_config = $3; } | OTHER CONFIG bool { RADV_IFACE->other_config = $3; }
| LINK MTU expr { RADV_IFACE->link_mtu = $3; } | LINK MTU expr { RADV_IFACE->link_mtu = $3; }

View file

@ -1,6 +1,8 @@
/* /*
* BIRD -- RAdv Packet Processing * BIRD -- RAdv Packet Processing
* *
* (c) 2011--2019 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2011--2019 CZ.NIC z.s.p.o.
* *
* Can be freely distributed and used under the terms of the GNU GPL. * Can be freely distributed and used under the terms of the GNU GPL.
*/ */
@ -370,19 +372,49 @@ radv_prepare_ra(struct radv_iface *ifa)
void void
radv_send_ra(struct radv_iface *ifa) radv_send_ra(struct radv_iface *ifa, ip_addr to)
{ {
struct radv_proto *p = ifa->ra; struct radv_proto *p = ifa->ra;
/* TX queue is already full */
if (!sk_tx_buffer_empty(ifa->sk))
return;
if (ifa->valid_time <= current_time())
radv_invalidate(ifa);
/* We store prepared RA in tbuf */ /* We store prepared RA in tbuf */
if (!ifa->plen) if (!ifa->plen)
radv_prepare_ra(ifa); radv_prepare_ra(ifa);
RADV_TRACE(D_PACKETS, "Sending RA via %s", ifa->iface->name); if (ipa_zero(to))
sk_send_to(ifa->sk, ifa->plen, IP6_ALL_NODES, 0); {
to = IP6_ALL_NODES;
RADV_TRACE(D_PACKETS, "Sending RA via %s", ifa->iface->name);
}
else
{
RADV_TRACE(D_PACKETS, "Sending RA to %I via %s", to, ifa->iface->name);
}
int done = sk_send_to(ifa->sk, ifa->plen, to, 0);
if (!done)
log(L_WARN "%s: TX queue full on %s", p->p.name, ifa->iface->name);
} }
static void
radv_receive_rs(struct radv_proto *p, struct radv_iface *ifa, ip_addr from)
{
RADV_TRACE(D_PACKETS, "Received RS from %I via %s",
from, ifa->iface->name);
if (ifa->cf->solicited_ra_unicast && ipa_nonzero(from))
radv_send_ra(ifa, from);
else
radv_iface_notify(ifa, RA_EV_RS);
}
static int static int
radv_rx_hook(sock *sk, uint size) radv_rx_hook(sock *sk, uint size)
{ {
@ -410,9 +442,7 @@ radv_rx_hook(sock *sk, uint size)
switch (buf[0]) switch (buf[0])
{ {
case ICMPV6_RS: case ICMPV6_RS:
RADV_TRACE(D_PACKETS, "Received RS from %I via %s", radv_receive_rs(p, ifa, sk->faddr);
sk->faddr, ifa->iface->name);
radv_iface_notify(ifa, RA_EV_RS);
return 1; return 1;
case ICMPV6_RA: case ICMPV6_RA:
@ -430,7 +460,10 @@ static void
radv_tx_hook(sock *sk) radv_tx_hook(sock *sk)
{ {
struct radv_iface *ifa = sk->data; struct radv_iface *ifa = sk->data;
log(L_WARN "%s: TX hook called", ifa->ra->p.name); log(L_INFO "%s: TX queue ready on %s", ifa->ra->p.name, ifa->iface->name);
/* Some RAs may be missed due to full TX queue */
radv_iface_notify(ifa, RA_EV_RS);
} }
static void static void

View file

@ -1,6 +1,8 @@
/* /*
* BIRD -- Router Advertisement * BIRD -- Router Advertisement
* *
* (c) 2011--2019 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2011--2019 CZ.NIC z.s.p.o.
* *
* Can be freely distributed and used under the terms of the GNU GPL. * Can be freely distributed and used under the terms of the GNU GPL.
*/ */
@ -35,18 +37,14 @@
* case of the specified trigger prefix was changed. * case of the specified trigger prefix was changed.
* *
* Supported standards: * Supported standards:
* - RFC 4861 - main RA standard * RFC 4861 - main RA standard
* - RFC 4191 - Default Router Preferences and More-Specific Routes * RFC 4191 - Default Router Preferences and More-Specific Routes
* - RFC 6106 - DNS extensions (RDDNS, DNSSL) * RFC 6106 - DNS extensions (RDDNS, DNSSL)
*/ */
static void radv_prune_prefixes(struct radv_iface *ifa); static void radv_prune_prefixes(struct radv_iface *ifa);
static void radv_prune_routes(struct radv_proto *p); static void radv_prune_routes(struct radv_proto *p);
/* Invalidate cached RA packet */
static inline void radv_invalidate(struct radv_iface *ifa)
{ ifa->plen = 0; }
static void static void
radv_timer(timer *tm) radv_timer(timer *tm)
{ {
@ -56,16 +54,13 @@ radv_timer(timer *tm)
RADV_TRACE(D_EVENTS, "Timer fired on %s", ifa->iface->name); RADV_TRACE(D_EVENTS, "Timer fired on %s", ifa->iface->name);
if (ifa->valid_time <= now)
radv_invalidate(ifa);
if (ifa->prune_time <= now) if (ifa->prune_time <= now)
radv_prune_prefixes(ifa); radv_prune_prefixes(ifa);
if (p->prune_time <= now) if (p->prune_time <= now)
radv_prune_routes(p); radv_prune_routes(p);
radv_send_ra(ifa); radv_send_ra(ifa, IPA_NONE);
/* Update timer */ /* Update timer */
ifa->last = now; ifa->last = now;
@ -627,7 +622,7 @@ radv_iface_shutdown(struct radv_iface *ifa)
if (ifa->sk) if (ifa->sk)
{ {
radv_invalidate(ifa); radv_invalidate(ifa);
radv_send_ra(ifa); radv_send_ra(ifa, IPA_NONE);
} }
} }

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@ -1,6 +1,8 @@
/* /*
* BIRD -- Router Advertisement * BIRD -- Router Advertisement
* *
* (c) 2011--2019 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2011--2019 CZ.NIC z.s.p.o.
* *
* Can be freely distributed and used under the terms of the GNU GPL. * Can be freely distributed and used under the terms of the GNU GPL.
*/ */
@ -66,6 +68,8 @@ struct radv_iface_config
u32 max_ra_int; u32 max_ra_int;
u32 min_delay; u32 min_delay;
u8 solicited_ra_unicast; /* Send solicited RAs as unicast */
u32 prefix_linger_time; /* How long we advertise dead prefixes with lifetime 0 */ u32 prefix_linger_time; /* How long we advertise dead prefixes with lifetime 0 */
u32 route_linger_time; /* How long we advertise dead routes with lifetime 0 */ u32 route_linger_time; /* How long we advertise dead routes with lifetime 0 */
@ -204,12 +208,16 @@ struct radv_iface
log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0) log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
/* Invalidate cached RA packet */
static inline void radv_invalidate(struct radv_iface *ifa)
{ ifa->plen = 0; }
/* radv.c */ /* radv.c */
void radv_iface_notify(struct radv_iface *ifa, int event); void radv_iface_notify(struct radv_iface *ifa, int event);
/* packets.c */ /* packets.c */
int radv_process_domain(struct radv_dnssl_config *cf); int radv_process_domain(struct radv_dnssl_config *cf);
void radv_send_ra(struct radv_iface *ifa); void radv_send_ra(struct radv_iface *ifa, ip_addr to);
int radv_sk_open(struct radv_iface *ifa); int radv_sk_open(struct radv_iface *ifa);