[PATCH] odhcpd: add option for setting preferred lifetime
vincent at systemli.org
vincent at systemli.org
Fri Jan 1 15:14:04 EST 2021
From: Nick Hainke <vincent at systemli.org>
"valid_lft" and "preferred_lft" are different. If the "preferred_lft"
is expired the prefix should be avoided in source prefix selection.
However, the interface is allowed to still receive downstream traffic.
ra_use_preferred_lft:
Value for the preferred lifetime for a prefix
ra_preferred_lft:
Use the limit for preferred lifetime of a prefix
If only "useleasetime" is set odhcpd will still set the "preferred_lft"
to the leasetime. If "ra_use_preferred_lft" is also set the
"preferred_lft" will be set to "ra_preferred_lft".
Signed-off-by: Nick Hainke <vincent at systemli.org>
---
README | 4 ++++
src/config.c | 15 +++++++++++++++
src/dhcpv6-ia.c | 20 ++++++++++++++++----
src/odhcpd.h | 3 +++
src/router.c | 4 ++++
5 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/README b/README
index a34a93c..6a5c6cf 100644
--- a/README
+++ b/README
@@ -129,6 +129,10 @@ ra_lifetime integer 1800 Value to be placed in Router
ra_useleasetime bool 0 Use configured leasetime as
limit for the preferred and
valid lifetime of a prefix
+ra_preferred_lft string 12h Value for the preferred lifetime
+ for a prefix
+ra_use_preferred_lft bool 0 Use the limit for preferred
+ lifetime of a prefix
ra_reachabletime integer 0 Reachable Time in milliseconds to be
advertised in RA messages
ra_retranstime integer 0 Retransmit Time in milliseconds to be
diff --git a/src/config.c b/src/config.c
index 015a716..cb06dfe 100644
--- a/src/config.c
+++ b/src/config.c
@@ -82,6 +82,8 @@ enum {
IFACE_ATTR_NDPROXY_ROUTING,
IFACE_ATTR_NDPROXY_SLAVE,
IFACE_ATTR_PREFIX_FILTER,
+ IFACE_ATTR_RA_USE_PREFERRED_LFT,
+ IFACE_ATTR_RA_PREFERRED_LFT,
IFACE_ATTR_MAX
};
@@ -130,6 +132,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
[IFACE_ATTR_NDPROXY_ROUTING] = { .name = "ndproxy_routing", .type = BLOBMSG_TYPE_BOOL },
[IFACE_ATTR_NDPROXY_SLAVE] = { .name = "ndproxy_slave", .type = BLOBMSG_TYPE_BOOL },
[IFACE_ATTR_PREFIX_FILTER] = { .name = "prefix_filter", .type = BLOBMSG_TYPE_STRING },
+ [IFACE_ATTR_RA_USE_PREFERRED_LFT] = { .name = "ra_use_preferred_lft", .type = BLOBMSG_TYPE_BOOL },
+ [IFACE_ATTR_RA_PREFERRED_LFT] = { .name = "ra_preferred_lft", .type = BLOBMSG_TYPE_STRING },
};
static const struct uci_blob_param_info iface_attr_info[IFACE_ATTR_MAX] = {
@@ -525,6 +529,14 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
iface->dhcp_leasetime = time;
}
+ if ((c = tb[IFACE_ATTR_RA_PREFERRED_LFT])) {
+ double time = parse_leasetime(c);
+ if (time < 0)
+ goto err;
+
+ iface->ra_preferred_lft = time;
+ }
+
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) +
@@ -795,6 +807,9 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
if ((c = tb[IFACE_ATTR_RA_USELEASETIME]))
iface->ra_useleasetime = blobmsg_get_bool(c);
+ if ((c = tb[IFACE_ATTR_RA_USE_PREFERRED_LFT]))
+ iface->ra_use_preferred_lft = blobmsg_get_bool(c);
+
if ((c = tb[IFACE_ATTR_RA_DNS]))
iface->ra_dns = blobmsg_get_bool(c);
diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index d7848de..8fffeb7 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -247,6 +247,9 @@ void dhcpv6_ia_enum_addrs(struct interface *iface, struct dhcp_assignment *c,
addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
}
+ if (pref > (uint32_t)c->preferred_until)
+ pref = c->preferred_until;
+
if (pref > (uint32_t)c->valid_until)
pref = c->valid_until;
@@ -827,14 +830,18 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
}
if (a) {
- uint32_t leasetime;
+ uint32_t leasetime, pref;
if (a->leasetime)
leasetime = a->leasetime;
else
leasetime = iface->dhcp_leasetime;
+
+ if (iface->ra_use_preferred_lft)
+ pref = iface->ra_preferred_lft;
+ else
+ pref = leasetime;
- uint32_t pref = leasetime;
uint32_t valid = leasetime;
struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
@@ -851,8 +858,8 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
if (prefix_pref != UINT32_MAX)
prefix_pref -= now;
- if (prefix_pref > leasetime)
- prefix_pref = leasetime;
+ if (prefix_pref > pref)
+ prefix_pref = pref;
if (prefix_valid != UINT32_MAX)
prefix_valid -= now;
@@ -918,6 +925,10 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
/* UINT32_MAX is considered as infinite leasetime */
a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
+ if (!INFINITE_VALID(a->preferred_until))
+ /* UINT32_MAX is considered as infinite leasetime */
+ a->preferred_until = (pref == UINT32_MAX) ? 0 : pref + now;
+
o_ia.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
o_ia.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
@@ -1261,6 +1272,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
a->peer = *addr;
a->assigned = is_na && l ? l->hostid : reqhint;
a->valid_until = now;
+ a->preferred_until = now;
a->dhcp_free_cb = dhcpv6_ia_free_assignment;
a->iface = iface;
a->flags = (is_pd ? OAF_DHCPV6_PD : OAF_DHCPV6_NA);
diff --git a/src/odhcpd.h b/src/odhcpd.h
index 2f7dd25..9df53a8 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -182,6 +182,7 @@ struct dhcp_assignment {
struct sockaddr_in6 peer;
time_t valid_until;
+ time_t preferred_until;
#define fr_timer reconf_timer
struct uloop_timeout reconf_timer;
@@ -286,6 +287,8 @@ struct interface {
uint32_t ra_retranstime;
uint32_t ra_hoplimit;
int ra_mtu;
+ bool ra_use_preferred_lft;
+ uint32_t ra_preferred_lft;
// DHCP
uint32_t dhcp_leasetime;
diff --git a/src/router.c b/src/router.c
index 06f3a66..244e600 100644
--- a/src/router.c
+++ b/src/router.c
@@ -554,6 +554,10 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
if (iface->ra_useleasetime &&
preferred > iface->dhcp_leasetime)
preferred = iface->dhcp_leasetime;
+
+ if (iface->ra_use_preferred_lft &&
+ preferred > iface->ra_preferred_lft)
+ preferred = iface->ra_preferred_lft;
}
valid = TIME_LEFT(addr->valid, now);
--
2.29.2
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