#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
+#include <arpa/inet.h>
#include <net/route.h>
#include "router.h"
static void handle_icmpv6(void *addr, void *data, size_t len,
struct interface *iface, void *dest);
static void trigger_router_advert(struct uloop_timeout *event);
-static void sigusr1_refresh(int signal);
+static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info);
-static struct odhcpd_event router_event = {{.fd = -1}, handle_icmpv6};
+static struct odhcpd_event router_event = {.uloop = {.fd = -1}, .handle_dgram = handle_icmpv6, };
+static struct netevent_handler router_netevent_handler = { .cb = router_netevent_cb, };
static FILE *fp_route = NULL;
-int init_router(void)
+#define TIME_LEFT(t1, now) ((t1) != UINT32_MAX ? (t1) - (now) : UINT32_MAX)
+
+int router_init(void)
{
// Open ICMPv6 socket
int sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
if (sock < 0 && errno != EAFNOSUPPORT) {
- syslog(LOG_ERR, "Failed to open RAW-socket: %s", strerror(errno));
+ syslog(LOG_ERR, "Failed to open RAW-socket: %m");
return -1;
}
odhcpd_register(&router_event);
if (!(fp_route = fopen("/proc/net/ipv6_route", "r")))
- syslog(LOG_ERR, "Failed to open routing table: %s",
- strerror(errno));
+ syslog(LOG_ERR, "Failed to open routing table: %m");
+
+ netlink_add_netevent_handler(&router_netevent_handler);
- signal(SIGUSR1, sigusr1_refresh);
return 0;
}
-int setup_router_interface(struct interface *iface, bool enable)
+int router_setup_interface(struct interface *iface, bool enable)
{
if (!fp_route || router_event.uloop.fd < 0)
return -1;
uloop_timeout_cancel(&iface->timer_rs);
iface->timer_rs.cb = NULL;
+ if (iface->ifindex <= 0)
+ return -1;
+
setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
&all_nodes, sizeof(all_nodes));
setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
} else {
void *mreq = &all_routers;
- if (iface->ra == RELAYD_RELAY && iface->master) {
+ if (iface->ra == MODE_RELAY && iface->master) {
mreq = &all_nodes;
forward_router_solicitation(iface);
- } else if (iface->ra == RELAYD_SERVER && !iface->master) {
+ } else if (iface->ra == MODE_SERVER && !iface->master) {
iface->timer_rs.cb = trigger_router_advert;
- trigger_router_advert(&iface->timer_rs);
+ uloop_timeout_set(&iface->timer_rs, 1000);
}
- if (iface->ra == RELAYD_RELAY || (iface->ra == RELAYD_SERVER && !iface->master))
+ if (iface->ra == MODE_RELAY || (iface->ra == MODE_SERVER && !iface->master))
setsockopt(router_event.uloop.fd, IPPROTO_IPV6,
IPV6_ADD_MEMBERSHIP, mreq, sizeof(all_nodes));
}
}
-// Signal handler to resend all RDs
-static void sigusr1_refresh(_unused int signal)
+static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info)
{
struct interface *iface;
- list_for_each_entry(iface, &interfaces, head)
- if (iface->ra == RELAYD_SERVER && !iface->master)
+
+ switch (event) {
+ case NETEV_ROUTE6_ADD:
+ case NETEV_ROUTE6_DEL:
+ if (info->rt.dst_len)
+ break;
+
+ list_for_each_entry(iface, &interfaces, head) {
+ if (iface->ra == MODE_SERVER && !iface->master)
+ uloop_timeout_set(&iface->timer_rs, 1000);
+ }
+ break;
+ case NETEV_ADDR6LIST_CHANGE:
+ iface = info->iface;
+ if (iface && iface->ra == MODE_SERVER && !iface->master)
uloop_timeout_set(&iface->timer_rs, 1000);
+ break;
+ default:
+ break;
+ }
}
+
static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size_t len)
{
struct icmp6_hdr *hdr = (struct icmp6_hdr *)data;
char line[512], ifname[16];
bool found_default = false;
- struct odhcpd_ipaddr p = {IN6ADDR_ANY_INIT, 0, 0, 0, 0};
+ struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0,
+ .dprefix = 0, .preferred = 0, .valid = 0};
+
while (fgets(line, sizeof(line), fp_route)) {
uint32_t rflags;
if (sscanf(line, "00000000000000000000000000000000 00 "
found_default = true;
} else if (sscanf(line, "%8" SCNx32 "%8" SCNx32 "%*8" SCNx32 "%*8" SCNx32 " %hhx %*s "
"%*s 00000000000000000000000000000000 %*s %*s %*s %" SCNx32 " lo",
- &p.addr.s6_addr32[0], &p.addr.s6_addr32[1], &p.prefix, &rflags) &&
+ &p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix, &rflags) &&
p.prefix > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
// Find source prefixes by scanning through unreachable-routes
- p.addr.s6_addr32[0] = htonl(p.addr.s6_addr32[0]);
- p.addr.s6_addr32[1] = htonl(p.addr.s6_addr32[1]);
+ p.addr.in6.s6_addr32[0] = htonl(p.addr.in6.s6_addr32[0]);
+ p.addr.in6.s6_addr32[1] = htonl(p.addr.in6.s6_addr32[1]);
for (ssize_t i = 0; i < len; ++i) {
if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
- !odhcpd_bmemcmp(&p.addr, &n[i].addr, p.prefix)) {
+ !odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix)) {
n[i].dprefix = p.prefix;
break;
}
return found_default;
}
+static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
+ uint32_t *maxival)
+{
+ uint32_t minival = iface->ra_mininterval;
+ int msecs;
+
+ *maxival = iface->ra_maxinterval;
+
+ if (*maxival > minvalid/3)
+ *maxival = minvalid/3;
+
+ if (*maxival > MaxRtrAdvInterval)
+ *maxival = MaxRtrAdvInterval;
+ else if (*maxival < 4)
+ *maxival = 4;
+
+ if (minival < MinRtrAdvInterval)
+ minival = MinRtrAdvInterval;
+ else if (minival > (*maxival * 3)/4)
+ minival = (*maxival >= 9 ? *maxival/3 : *maxival);
+
+ odhcpd_urandom(&msecs, sizeof(msecs));
+ msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
+ minival*1000;
+
+ return msecs;
+}
+
+static uint16_t calc_ra_lifetime(struct interface *iface, uint32_t maxival)
+{
+ uint16_t lifetime = 3*maxival;
+
+ if (iface->ra_lifetime >= 0) {
+ lifetime = iface->ra_lifetime;
+ if (lifetime < maxival)
+ lifetime = maxival;
+ else if (lifetime > 9000)
+ lifetime = 9000;
+ }
+
+ return lifetime;
+}
+
+enum {
+ IOV_RA_ADV=0,
+ IOV_RA_PFXS,
+ IOV_RA_ROUTES,
+ IOV_RA_DNS,
+ IOV_RA_DNS_ADDR,
+ IOV_RA_SEARCH,
+ IOV_RA_ADV_INTERVAL,
+ IOV_RA_TOTAL,
+};
// Router Advert server mode
static uint64_t send_router_advert(struct interface *iface, const struct in6_addr *from)
{
- int mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
- int hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
+ time_t now = odhcpd_time();
+ int mtu = iface->ra_mtu;
+ int hlim = iface->ra_hoplimit;
+
+ if (mtu == 0)
+ mtu = odhcpd_get_interface_config(iface->ifname, "mtu");
if (mtu < 1280)
mtu = 1280;
+ if (hlim == 0)
+ hlim = odhcpd_get_interface_config(iface->ifname, "hop_limit");
+
struct {
struct nd_router_advert h;
struct icmpv6_opt lladdr;
struct nd_opt_mtu mtu;
- struct nd_opt_prefix_info prefix[RELAYD_MAX_PREFIXES];
} adv = {
.h = {{.icmp6_type = ND_ROUTER_ADVERT, .icmp6_code = 0}, 0, 0},
.lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}},
if (hlim > 0)
adv.h.nd_ra_curhoplimit = hlim;
- if (iface->dhcpv6)
+ if (iface->dhcpv6) {
adv.h.nd_ra_flags_reserved = ND_RA_FLAG_OTHER;
- if (iface->managed >= RELAYD_MANAGED_MFLAG)
- adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
+ if (iface->ra_managed >= RA_MANAGED_MFLAG)
+ adv.h.nd_ra_flags_reserved |= ND_RA_FLAG_MANAGED;
+ }
if (iface->route_preference < 0)
adv.h.nd_ra_flags_reserved |= ND_RA_PREF_LOW;
else if (iface->route_preference > 0)
adv.h.nd_ra_flags_reserved |= ND_RA_PREF_HIGH;
+
+ adv.h.nd_ra_reachable = htonl(iface->ra_reachabletime);
+ adv.h.nd_ra_retransmit = htonl(iface->ra_retranstime);
+
odhcpd_get_mac(iface, adv.lladdr.data);
// If not currently shutting down
- struct odhcpd_ipaddr addrs[RELAYD_MAX_PREFIXES];
+ struct odhcpd_ipaddr *addrs = NULL;
ssize_t ipcnt = 0;
- uint64_t maxpreferred = 0;
+ uint32_t minvalid = UINT32_MAX;
+ bool default_route = false;
+ bool valid_prefix = false;
// If not shutdown
if (iface->timer_rs.cb) {
- ipcnt = odhcpd_get_interface_addresses(iface->ifindex,
- addrs, ARRAY_SIZE(addrs));
+ size_t size = sizeof(*addrs) * iface->addr6_len;
+ addrs = alloca(size);
+ memcpy(addrs, iface->addr6, size);
+
+ ipcnt = iface->addr6_len;
// Check default route
- if (parse_routes(addrs, ipcnt) || iface->default_router > 1)
- adv.h.nd_ra_router_lifetime =
- htons(3 * MaxRtrAdvInterval);
+ if (iface->default_router) {
+ default_route = true;
+
+ if (iface->default_router > 1)
+ valid_prefix = true;
+ } else if (parse_routes(addrs, ipcnt))
+ default_route = true;
}
- // Construct Prefix Information options
- bool have_public = false;
- size_t cnt = 0;
- struct in6_addr dns_pref = IN6ADDR_ANY_INIT, *dns_addr = &dns_pref;
- uint32_t dns_time = 0;
+ struct in6_addr dns_pref, *dns_addr = &dns_pref;
size_t dns_cnt = 1;
+ odhcpd_get_interface_dns_addr(iface, &dns_pref);
+
+ // Construct Prefix Information options
+ size_t pfxs_cnt = 0;
+ struct nd_opt_prefix_info *pfxs = NULL;
+
for (ssize_t i = 0; i < ipcnt; ++i) {
struct odhcpd_ipaddr *addr = &addrs[i];
- if (addr->prefix > 96)
- continue; // Address not suitable
+ uint32_t preferred = 0;
+ uint32_t valid = 0;
- if (addr->preferred > MaxPreferredTime)
- addr->preferred = MaxPreferredTime;
+ if (addr->prefix > 96 || addr->valid <= (uint32_t)now) {
+ char namebuf[INET6_ADDRSTRLEN];
- if (addr->valid > MaxValidTime)
- addr->valid = MaxValidTime;
+ inet_ntop(AF_INET6, &addr->addr.in6, namebuf, sizeof(namebuf));
+ syslog(LOG_INFO, "Address %s (prefix %d, valid %u) not suitable as RA prefix on %s",
+ namebuf, addr->prefix, addr->valid, iface->ifname);
+ continue;
+ }
+
+ if (odhcpd_bmemcmp(&addr->addr, &iface->pio_filter_addr,
+ iface->pio_filter_length) != 0 ||
+ addr->prefix < iface->pio_filter_length)
+ continue; // PIO filtered out of this RA
struct nd_opt_prefix_info *p = NULL;
- for (size_t i = 0; i < cnt; ++i) {
- if (addr->prefix == adv.prefix[i].nd_opt_pi_prefix_len &&
- !odhcpd_bmemcmp(&adv.prefix[i].nd_opt_pi_prefix,
- &addr->addr, addr->prefix))
- p = &adv.prefix[i];
+ for (size_t i = 0; i < pfxs_cnt; ++i) {
+ if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
+ !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
+ &addr->addr.in6, addr->prefix))
+ p = &pfxs[i];
}
if (!p) {
- if (cnt >= ARRAY_SIZE(adv.prefix))
- break;
+ struct nd_opt_prefix_info *tmp;
+
+ tmp = realloc(pfxs, sizeof(*pfxs) * (pfxs_cnt + 1));
+ if (!tmp) {
+ syslog(LOG_ERR, "Realloc failed for RA prefix option on interface %s", iface->ifname);
+ continue;
+ }
- p = &adv.prefix[cnt++];
+ pfxs = tmp;
+ p = &pfxs[pfxs_cnt++];
+ memset(p, 0, sizeof(*p));
}
- if ((addr->addr.s6_addr[0] & 0xfe) != 0xfc && addr->preferred > 0) {
- have_public = true;
+ if (addr->preferred > (uint32_t)now) {
+ preferred = TIME_LEFT(addr->preferred, now);
- if (maxpreferred < 1000 * addr->preferred)
- maxpreferred = 1000 * addr->preferred;
+ if (iface->ra_useleasetime &&
+ preferred > iface->dhcpv4_leasetime)
+ preferred = iface->dhcpv4_leasetime;
}
- odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr,
+ valid = TIME_LEFT(addr->valid, now);
+ if (iface->ra_useleasetime && valid > iface->dhcpv4_leasetime)
+ valid = iface->dhcpv4_leasetime;
+
+ if (minvalid > valid)
+ minvalid = valid;
+
+ if (!IN6_IS_ADDR_ULA(&addr->addr.in6) || iface->default_router)
+ valid_prefix = true;
+
+ odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
(iface->ra_advrouter) ? 128 : addr->prefix);
p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
p->nd_opt_pi_len = 4;
p->nd_opt_pi_flags_reserved = 0;
if (!iface->ra_not_onlink)
p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
- if (iface->managed < RELAYD_MANAGED_NO_AFLAG && addr->prefix <= 64)
+ if (iface->ra_managed < RA_MANAGED_NO_AFLAG && addr->prefix <= 64)
p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
if (iface->ra_advrouter)
p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_RADDR;
- p->nd_opt_pi_valid_time = htonl(addr->valid);
- p->nd_opt_pi_preferred_time = htonl(addr->preferred);
-
- if (addr->preferred > dns_time) {
- dns_time = addr->preferred;
- dns_pref = addr->addr;
- }
+ p->nd_opt_pi_preferred_time = htonl(preferred);
+ p->nd_opt_pi_valid_time = htonl(valid);
}
- if (!have_public && !iface->default_router && adv.h.nd_ra_router_lifetime) {
- syslog(LOG_WARNING, "A default route is present but there is no public prefix "
- "on %s thus we don't announce a default route!", iface->ifname);
+ // Calculate periodic transmit
+ uint32_t maxival;
+ int msecs = calc_adv_interval(iface, minvalid, &maxival);
+
+ if (default_route) {
+ if (!valid_prefix) {
+ syslog(LOG_WARNING, "A default route is present but there is no public prefix "
+ "on %s thus we don't announce a default route!", iface->ifname);
+ adv.h.nd_ra_router_lifetime = 0;
+ } else
+ adv.h.nd_ra_router_lifetime = htons(calc_ra_lifetime(iface, maxival));
+
+ } else
adv.h.nd_ra_router_lifetime = 0;
- }
+
+ syslog(LOG_INFO, "Using a RA lifetime of %d seconds on %s", ntohs(adv.h.nd_ra_router_lifetime), iface->ifname);
// DNS Recursive DNS
if (iface->dns_cnt > 0) {
dns_addr = iface->dns;
dns_cnt = iface->dns_cnt;
- dns_time = 2 * MaxRtrAdvInterval;
}
if (!dns_addr || IN6_IS_ADDR_UNSPECIFIED(dns_addr))
uint8_t pad;
uint8_t pad2;
uint32_t lifetime;
- } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, htonl(dns_time)};
-
-
+ } dns = {ND_OPT_RECURSIVE_DNS, (1 + (2 * dns_cnt)), 0, 0, 0};
// DNS Search options
uint8_t search_buf[256], *search_domain = iface->search;
search->len = search_len ? ((sizeof(*search) + search_padded) / 8) : 0;
search->pad = 0;
search->pad2 = 0;
- search->lifetime = htonl(2 * MaxRtrAdvInterval);;
memcpy(search->name, search_domain, search_len);
memset(&search->name[search_len], 0, search_padded - search_len);
uint8_t flags;
uint32_t lifetime;
uint32_t addr[4];
- } routes[RELAYD_MAX_PREFIXES];
+ } *tmp, *routes = NULL;
for (ssize_t i = 0; i < ipcnt; ++i) {
struct odhcpd_ipaddr *addr = &addrs[i];
- if (addr->dprefix > 64 || addr->dprefix == 0 ||
- (addr->dprefix == 64 && addr->prefix == 64)) {
+ if (addr->dprefix > 64 || addr->dprefix == 0 || addr->valid <= (uint32_t)now)
continue; // Address not suitable
- } else if (addr->dprefix > 32) {
- addr->addr.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
+
+ if (addr->dprefix > 32) {
+ addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
} else if (addr->dprefix <= 32) {
- addr->addr.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
- addr->addr.s6_addr32[1] = 0;
+ addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
+ addr->addr.in6.s6_addr32[1] = 0;
}
+ tmp = realloc(routes, sizeof(*routes) * (routes_cnt + 1));
+ if (!tmp) {
+ syslog(LOG_ERR, "Realloc failed for RA route option on interface %s", iface->ifname);
+ continue;
+ }
+
+ routes = tmp;
+
+ memset(&routes[routes_cnt], 0, sizeof(*routes));
routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
routes[routes_cnt].len = sizeof(*routes) / 8;
routes[routes_cnt].prefix = addr->dprefix;
routes[routes_cnt].flags |= ND_RA_PREF_LOW;
else if (iface->route_preference > 0)
routes[routes_cnt].flags |= ND_RA_PREF_HIGH;
- routes[routes_cnt].lifetime = htonl(addr->valid);
- routes[routes_cnt].addr[0] = addr->addr.s6_addr32[0];
- routes[routes_cnt].addr[1] = addr->addr.s6_addr32[1];
+ routes[routes_cnt].lifetime = htonl(TIME_LEFT(addr->valid, now));
+ routes[routes_cnt].addr[0] = addr->addr.in6.s6_addr32[0];
+ routes[routes_cnt].addr[1] = addr->addr.in6.s6_addr32[1];
routes[routes_cnt].addr[2] = 0;
routes[routes_cnt].addr[3] = 0;
++routes_cnt;
}
- // Calculate periodic transmit
- int msecs = 0;
- uint32_t maxival = MaxRtrAdvInterval * 1000;
- uint32_t minival = MinRtrAdvInterval * 1000;
-
- if (maxpreferred > 0 && maxival > maxpreferred / 2) {
- maxival = maxpreferred / 2;
- if (maxival < 4000)
- maxival = 4000;
-
- if (maxival >= 9000)
- minival = maxival / 3;
- else
- minival = (maxival * 3) / 4;
- }
-
- odhcpd_urandom(&msecs, sizeof(msecs));
- msecs = (labs(msecs) % (maxival - minival)) + minival;
+ search->lifetime = htonl(maxival*10);
+ dns.lifetime = search->lifetime;
struct icmpv6_opt adv_interval = {
.type = ND_OPT_RTR_ADV_INTERVAL,
.len = 1,
- .data = {0, 0, maxival >> 24, maxival >> 16, maxival >> 8, maxival}
+ .data = {0, 0, (maxival*1000) >> 24, (maxival*1000) >> 16, (maxival*1000) >> 8, maxival*1000}
};
- struct iovec iov[] = {{&adv, (uint8_t*)&adv.prefix[cnt] - (uint8_t*)&adv},
- {&routes, routes_cnt * sizeof(*routes)},
- {&dns, (dns_cnt) ? sizeof(dns) : 0},
- {dns_addr, dns_cnt * sizeof(*dns_addr)},
- {search, search->len * 8},
- {&adv_interval, adv_interval.len * 8}};
+ struct iovec iov[IOV_RA_TOTAL] = {
+ [IOV_RA_ADV] = {&adv, sizeof(adv)},
+ [IOV_RA_PFXS] = {pfxs, pfxs_cnt * sizeof(*pfxs)},
+ [IOV_RA_ROUTES] = {routes, routes_cnt * sizeof(*routes)},
+ [IOV_RA_DNS] = {&dns, (dns_cnt) ? sizeof(dns) : 0},
+ [IOV_RA_DNS_ADDR] = {dns_addr, dns_cnt * sizeof(*dns_addr)},
+ [IOV_RA_SEARCH] = {search, search->len * 8},
+ [IOV_RA_ADV_INTERVAL] = {&adv_interval, adv_interval.len * 8}};
struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_NODES, 0};
if (from && !IN6_IS_ADDR_UNSPECIFIED(from))
odhcpd_send(router_event.uloop.fd,
&dest, iov, ARRAY_SIZE(iov), iface);
+ free(pfxs);
+ free(routes);
+
return msecs;
}
if (!router_icmpv6_valid(addr, data, len))
return;
- if ((iface->ra == RELAYD_SERVER && !iface->master)) { // Server mode
+ if ((iface->ra == MODE_SERVER && !iface->master)) { // Server mode
if (hdr->icmp6_type == ND_ROUTER_SOLICIT)
send_router_advert(iface, &from->sin6_addr);
- } else if (iface->ra == RELAYD_RELAY) { // Relay mode
+ } else if (iface->ra == MODE_RELAY) { // Relay mode
if (hdr->icmp6_type == ND_ROUTER_ADVERT && iface->master)
forward_router_advertisement(data, len);
else if (hdr->icmp6_type == ND_ROUTER_SOLICIT && !iface->master)
struct interface *iface;
list_for_each_entry(iface, &interfaces, head) {
- if (iface->ra != RELAYD_RELAY || iface->master)
+ if (iface->ra != MODE_RELAY || iface->master)
continue;
// Fixup source hardware address option
size_t rewrite_cnt = iface->dns_cnt;
if (rewrite_cnt == 0) {
- if (odhcpd_get_preferred_interface_address(iface->ifindex, &addr) < 1)
+ if (odhcpd_get_interface_dns_addr(iface, &addr))
continue; // Unable to comply
rewrite = &addr;