odhcpd: add option for setting preferred lifetime

"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.

preferred_lfetime:
  Limit for preferred lifetime of a prefix

If you want the old behavior, you have to set preferred_lifetime to
the same value as leasetime.

Signed-off-by: Nick Hainke <vincent@systemli.org>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

diff --git a/README b/README
index a34a93c1ae08747b4a87c31f85273b374d6b60f4..f9cbb117004294a738add82945f4b3365fa484f0 100644 (file)
--- a/README
+++ b/README
@@ -110,7 +110,8 @@ domain                      list    <local search domain>   Search domains to announce
 leasetime              string  12h                     DHCPv4 address leasetime
 start                  integer 100                     DHCPv4 pool start
 limit                  integer 150                     DHCPv4 pool size
-
+preferred_lifetime     string  12h                     Value for the preferred lifetime
+                                                       for a prefix
 ra_default             integer 0                       Override default route
                        0: default, 1: ignore no public address, 2: ignore all
 ra_flags               list    other-config            List of RA flags to be

diff --git a/src/config.c b/src/config.c
index 015a716dd1cf2de877108f1c670927b66045d2aa..78b58550040061ce2c056e94b28d50e554edaace 100644 (file)
--- a/src/config.c
+++ b/src/config.c
@@ -82,6 +82,7 @@ enum {
        IFACE_ATTR_NDPROXY_ROUTING,
        IFACE_ATTR_NDPROXY_SLAVE,
        IFACE_ATTR_PREFIX_FILTER,
+       IFACE_ATTR_PREFERRED_LIFETIME,
        IFACE_ATTR_MAX
 };
 
@@ -130,6 +131,7 @@ 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_PREFERRED_LIFETIME] = { .name = "preferred_lifetime", .type = BLOBMSG_TYPE_STRING },
 };
 
 static const struct uci_blob_param_info iface_attr_info[IFACE_ATTR_MAX] = {
@@ -197,6 +199,7 @@ static void set_interface_defaults(struct interface *iface)
        iface->ndp = MODE_DISABLED;
        iface->learn_routes = 1;
        iface->dhcp_leasetime = 43200;
+       iface->preferred_lifetime = 43200;
        iface->dhcpv4_start.s_addr = htonl(START_DEFAULT);
        iface->dhcpv4_end.s_addr = htonl(START_DEFAULT + LIMIT_DEFAULT - 1);
        iface->dhcpv6_assignall = true;
@@ -525,6 +528,14 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
                iface->dhcp_leasetime = time;
        }
 
+       if ((c = tb[IFACE_ATTR_PREFERRED_LIFETIME])) {
+               double time = parse_leasetime(c);
+               if (time < 0)
+                       goto err;
+
+               iface->preferred_lifetime = 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) +

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index d7848de4638bfb9115fa053adba676cfe836464a..a59fc20f9054723d35d347968d1a5231582fc6e9 100644 (file)
--- 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 +830,16 @@ 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)
+               if (a->leasetime) {
                        leasetime = a->leasetime;
-               else
+                       pref = a->leasetime;
+               } else {
                        leasetime = iface->dhcp_leasetime;
+                       pref = iface->preferred_lifetime;
+               }
 
-               uint32_t pref = leasetime;
                uint32_t valid = leasetime;
 
                struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
@@ -851,8 +856,8 @@ 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 +923,10 @@ 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 +1270,7 @@ 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 2f7dd25291396d6b09f71d7ce17d1d70a088a68e..45b6784ce0986acd5167d49d10ee58122c77cd22 100644 (file)
--- 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 +287,7 @@ struct interface {
        uint32_t ra_retranstime;
        uint32_t ra_hoplimit;
        int ra_mtu;
+       uint32_t preferred_lifetime;
 
        // DHCP
        uint32_t dhcp_leasetime;

diff --git a/src/router.c b/src/router.c
index 06f3a668c4438e0711c8a3acb03851c662a74f09..d6ab4bb517ff67ca68491504a94f97a192b7720e 100644 (file)
--- a/src/router.c
+++ b/src/router.c
@@ -552,8 +552,8 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
                        preferred = TIME_LEFT(addr->preferred, now);
 
                        if (iface->ra_useleasetime &&
-                           preferred > iface->dhcp_leasetime)
-                               preferred = iface->dhcp_leasetime;
+                           preferred > iface->preferred_lifetime)
+                               preferred = iface->preferred_lifetime;
                }
 
                valid = TIME_LEFT(addr->valid, now);