Fixed IPv6 RA router lifetime misbehavours

Signed-off-by: Nicholas Sun <nicholas-sun@outlook.com>

Author: nicholas-opensource

PATCH/odhcpd/001-config-allow-configuring-limit-of-min-and-max-value.patch

@@ -1,16 +1,35 @@
-From 8a8150f045ed73e15c77c38be4b90999024f6d17 Mon Sep 17 00:00:00 2001
+From 9ee21c537eea6321ed644e284a1d9c13de342fef Mon Sep 17 00:00:00 2001
 From: skbeh <60107333+skbeh@users.noreply.github.com>
 Date: Sat, 16 Sep 2023 15:04:12 +0000
 Subject: [PATCH] config: allow configuring max limit for preferred and valid
  lifetime
 
 ---
+ README          |  5 +++--
  src/config.c    | 32 ++++++++++++++++++++++++++++++++
  src/dhcpv6-ia.c |  9 +++++++++
  src/odhcpd.h    |  6 ++++++
- src/router.c    | 35 +++++++++++++++++++++++++++--------
- 4 files changed, 74 insertions(+), 8 deletions(-)
+ src/router.c    | 37 +++++++++++++++++++++++++++++--------
+ 5 files changed, 79 insertions(+), 10 deletions(-)
 
+diff --git a/README b/README
+index 8f0e6a4..ddf8534 100644
+--- a/README
++++ b/README
+@@ -130,8 +130,9 @@ ra_maxinterval		integer	600			Maximum time allowed between
+ 							sending unsolicited RA
+ ra_mininterval		integer	200			Minimum time allowed between
+ 							sending unsolicited RA
+-ra_lifetime		integer	1800			Value to be placed in Router
+-							Lifetime field of RA
++ra_lifetime		integer	2700			Value to be placed in Router
++							Lifetime field of RA. Not recommended to be
++							more than 2700 (RFC9096).
+ ra_useleasetime		bool	0			Use configured leasetime as
+ 							limit for the preferred and
+ 							valid lifetime of a prefix
+diff --git a/src/config.c b/src/config.c
+index e631814..3281b5f 100644
 --- a/src/config.c
 +++ b/src/config.c
 @@ -92,6 +92,8 @@ enum {
@@ -22,7 +41,7 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  	IFACE_ATTR_NTP,
  	IFACE_ATTR_MAX
  };
-@@ -145,6 +147,8 @@ static const struct blobmsg_policy iface
+@@ -145,6 +147,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
  	[IFACE_ATTR_NDPROXY_SLAVE] = { .name = "ndproxy_slave", .type = BLOBMSG_TYPE_BOOL },
  	[IFACE_ATTR_PREFIX_FILTER] = { .name = "prefix_filter", .type = BLOBMSG_TYPE_STRING },
  	[IFACE_ATTR_PREFERRED_LIFETIME] = { .name = "preferred_lifetime", .type = BLOBMSG_TYPE_STRING },
@@ -31,7 +50,7 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  	[IFACE_ATTR_NTP] = { .name = "ntp", .type = BLOBMSG_TYPE_ARRAY },
  };
 
-@@ -648,6 +652,34 @@ int config_parse_interface(void *data, s
+@@ -648,6 +652,34 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
  	}
 
@@ -66,9 +85,11 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  	if ((c = tb[IFACE_ATTR_START])) {
  		iface->dhcpv4_start.s_addr = htonl(blobmsg_get_u32(c));
  		iface->dhcpv4_end.s_addr = htonl(ntohl(iface->dhcpv4_start.s_addr) +
+diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
+index 41c9f30..b413ab4 100644
 --- a/src/dhcpv6-ia.c
 +++ b/src/dhcpv6-ia.c
-@@ -1027,6 +1027,15 @@ static size_t build_ia(uint8_t *buf, siz
+@@ -1027,6 +1027,15 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
  			}
  		}
 
@@ -84,6 +105,8 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  		if (!INFINITE_VALID(a->valid_until))
  			/* UINT32_MAX is considered as infinite leasetime */
  			a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
+diff --git a/src/odhcpd.h b/src/odhcpd.h
+index 08b4920..58ab155 100644
 --- a/src/odhcpd.h
 +++ b/src/odhcpd.h
 @@ -37,6 +37,10 @@
@@ -106,9 +129,11 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
 
  	// DHCP
  	uint32_t dhcp_leasetime;
+diff --git a/src/router.c b/src/router.c
+index d5ef7f8..55eaa6d 100644
 --- a/src/router.c
 +++ b/src/router.c
-@@ -452,7 +452,8 @@ static int send_router_advert(struct int
+@@ -452,7 +452,8 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
  	size_t dns_sz = 0, search_sz = 0, pref64_sz = 0;
  	size_t pfxs_cnt = 0, routes_cnt = 0;
  	ssize_t valid_addr_cnt = 0, invalid_addr_cnt = 0;
@@ -118,7 +143,7 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  	int msecs, mtu = iface->ra_mtu, hlim = iface->ra_hoplimit;
  	bool default_route = false;
  	bool valid_prefix = false;
-@@ -598,10 +599,22 @@ static int send_router_advert(struct int
+@@ -598,10 +599,24 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
  		if (addr->valid > (uint32_t)now) {
  			valid = TIME_LEFT(addr->valid, now);
 
@@ -130,23 +155,25 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  		}
 
 +		if (preferred) {
-+			if (iface->max_preferred_lifetime)
++			if (iface->max_preferred_lifetime) {
 +				preferred = min(preferred, iface->max_preferred_lifetime);
++			}
 +		}
 +		if (valid) {
-+			if (iface->max_valid_lifetime)
++			if (iface->max_valid_lifetime) {
 +				valid = min(valid, iface->max_valid_lifetime);
++			}
 +		}
 +
  		if (minvalid > valid)
  			minvalid = valid;
 
-@@ -629,24 +642,30 @@ static int send_router_advert(struct int
+@@ -629,24 +644,30 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 
  	/* Calculate periodic transmit */
  	msecs = calc_adv_interval(iface, minvalid, &maxival);
 -	lifetime = calc_ra_lifetime(iface, maxival);
-+	calculated_ra_lifetime = calc_ra_lifetime(iface, maxival);
++	calculated_ra_lifetime = min(calc_ra_lifetime(iface, maxival), UINT16_MAX);
 +	lifetime = min(calculated_ra_lifetime, max_prefix_vlt);
 
  	if (!iface->have_link_local) {
@@ -158,7 +185,7 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
 -		adv.h.nd_ra_router_lifetime = htons(lifetime < UINT16_MAX ? lifetime : UINT16_MAX);
 -	} else {
 +	/* RFC9096: CE routers SHOULD set the "Router Lifetime" of Router Advertisement (RA) messages to ND_PREFERRED_LIMIT. */
-+	adv.h.nd_ra_router_lifetime = ND_PREFERRED_LIMIT;
++	adv.h.nd_ra_router_lifetime = htons(ND_PREFERRED_LIMIT);
 +	if (!(default_route && valid_prefix)) {
  		adv.h.nd_ra_router_lifetime = 0;
 
@@ -171,14 +198,14 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
 +			syslog(LOG_WARNING, "No default route present, setting ra_lifetime to zero!");
  		}
 +	} else if (iface->ra_lifetime >= 0) {
-+		adv.h.nd_ra_router_lifetime = calculated_ra_lifetime;
++		adv.h.nd_ra_router_lifetime = htons(calculated_ra_lifetime);
 +		if (calculated_ra_lifetime == 0)
 +			syslog(LOG_WARNING, "A default route is present and there is public prefix "
 +						"but ra_lifetime on iface was set to zero, setting ra_lifetime to zero!");
  	}
 
  	syslog(LOG_DEBUG, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->name);
-@@ -710,7 +729,7 @@ static int send_router_advert(struct int
+@@ -710,7 +731,7 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 
  	if (iface->pref64_length) {
  		/* RFC 8781 § 4.1 rounding up lifetime to multiply of 8 */
@@ -187,3 +214,5 @@ Subject: [PATCH] config: allow configuring max limit for preferred and valid
  		uint8_t prefix_length_code;
  		uint32_t mask_a1, mask_a2;
 
+-- 
+2.42.0