Merge pull request #999 from adamdunkels/lebrush-rdnss-support-rebased

RDNSS support, again

apps/dhcp/dhcp.c

@@ -88,7 +88,7 @@ makestrings(void)
   uip_getdraddr(&addr);
   makeaddr(&addr, gateway);
 
-  addrptr = resolv_getserver();
+  addrptr = uip_nameserver_get(0);
   if(addrptr != NULL) {
     makeaddr(addrptr, dnsserver);
   }
@@ -147,7 +147,7 @@ dhcpc_configured(const struct dhcpc_state *s)
   uip_sethostaddr(&s->ipaddr);
   uip_setnetmask(&s->netmask);
   uip_setdraddr(&s->default_router);
-  resolv_conf(&s->dnsaddr);
+  uip_nameserver_update(&s->dnsaddr, UIP_NAMESERVER_INFINITE_LIFETIME);
   set_statustext("Configured.");
   process_post(PROCESS_CURRENT(), SHOWCONFIG, NULL);
 }

apps/netconf/netconf.c

@@ -113,7 +113,7 @@ makestrings(void)
   makeaddr(&addr, gateway);
 
 #if UIP_UDP
-  addrptr = resolv_getserver();
+  addrptr = uip_nameserver_get(0);
   if(addrptr != NULL) {
     makeaddr(addrptr, dnsserver);
   }
@@ -152,7 +152,7 @@ apply_tcpipconfig(void)
 #if UIP_UDP
   nullterminate(dnsserver);
   if(uiplib_ipaddrconv(dnsserver, &addr)) {
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
   }
 #endif /* UIP_UDP */
 }

core/contiki-net.h

@@ -44,6 +44,7 @@
 #include "net/ip/uiplib.h"
 #include "net/ip/uip-udp-packet.h"
 #include "net/ip/simple-udp.h"
+#include "net/ip/uip-nameserver.h"
 
 #if NETSTACK_CONF_WITH_IPV6
 #include "net/ipv6/uip-icmp6.h"

core/net/ip/resolv.c

@@ -65,6 +65,7 @@
 #include "net/ip/tcpip.h"
 #include "net/ip/resolv.h"
 #include "net/ip/uip-udp-packet.h"
+#include "net/ip/uip-nameserver.h"
 #include "lib/random.h"
 
 #ifndef DEBUG
@@ -227,17 +228,6 @@ struct dns_hdr {
   uint16_t numextrarr;
 };
 
-/** These default values for the DNS server are Google's public DNS:
- *  <https://developers.google.com/speed/public-dns/docs/using>
- */
-static uip_ipaddr_t resolv_default_dns_server =
-#if NETSTACK_CONF_WITH_IPV6
-  { { 0x20, 0x01, 0x48, 0x60, 0x48, 0x60, 0x00, 0x00,
-      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x88, 0x88 } };
-#else /* NETSTACK_CONF_WITH_IPV6 */
-  { { 8, 8, 8, 8 } };
-#endif /* NETSTACK_CONF_WITH_IPV6 */
-
 /** \internal The DNS answer message structure. */
 struct dns_answer {
   /* DNS answer record starts with either a domain name or a pointer
@@ -269,6 +259,7 @@ struct namemap {
 #endif /* RESOLV_SUPPORTS_RECORD_EXPIRATION */
   uip_ipaddr_t ipaddr;
   uint8_t err;
+  uint8_t server;
 #if RESOLV_CONF_SUPPORTS_MDNS
   int is_mdns:1, is_probe:1;
 #endif
@@ -637,6 +628,21 @@ mdns_prep_host_announce_packet(void)
 }
 #endif /* RESOLV_CONF_SUPPORTS_MDNS */
 /*---------------------------------------------------------------------------*/
+static char
+try_next_server(struct namemap *namemapptr)
+{
+#if VERBOSE_DEBUG
+  printf("server %d\n", namemapptr->server);
+#endif
+  namemapptr->server++;
+  if(uip_nameserver_get(namemapptr->server) != NULL) {
+    namemapptr->retries = 0;
+    return 1;
+  }
+  namemapptr->server = 0;
+  return 0;
+}
+/*---------------------------------------------------------------------------*/
 /** \internal
  * Runs through the list of names to see if there are any that have
  * not yet been queried and, if so, sends out a query.
@@ -666,16 +672,20 @@ check_entries(void)
           if(++namemapptr->retries == RESOLV_CONF_MAX_RETRIES)
 #endif /* RESOLV_CONF_SUPPORTS_MDNS */
           {
-            /* STATE_ERROR basically means "not found". */
+            /* Try the next server (if possible) before failing. Otherwise
-            namemapptr->state = STATE_ERROR;
+               simply mark the entry as failed. */
+            if(try_next_server(namemapptr) == 0) {
+              /* STATE_ERROR basically means "not found". */
+              namemapptr->state = STATE_ERROR;
 
 #if RESOLV_SUPPORTS_RECORD_EXPIRATION
-            /* Keep the "not found" error valid for 30 seconds */
+              /* Keep the "not found" error valid for 30 seconds */
-            namemapptr->expiration = clock_seconds() + 30;
+              namemapptr->expiration = clock_seconds() + 30;
 #endif /* RESOLV_SUPPORTS_RECORD_EXPIRATION */
 
-            resolv_found(namemapptr->name, NULL);
+              resolv_found(namemapptr->name, NULL);
-            continue;
+              continue;
+            }
           }
           namemapptr->tmr = namemapptr->retries * namemapptr->retries * 3;
 
@@ -747,7 +757,9 @@ check_entries(void)
       } else {
         uip_udp_packet_sendto(resolv_conn, uip_appdata,
                               (query - (uint8_t *) uip_appdata),
-                              &resolv_default_dns_server, UIP_HTONS(DNS_PORT));
+                              (const uip_ipaddr_t *)
+                                uip_nameserver_get(namemapptr->server), 
+                              UIP_HTONS(DNS_PORT));
 
         PRINTF("resolver: (i=%d) Sent DNS request for \"%s\".\n", i,
                namemapptr->name);
@@ -755,7 +767,8 @@ check_entries(void)
 #else /* RESOLV_CONF_SUPPORTS_MDNS */
       uip_udp_packet_sendto(resolv_conn, uip_appdata,
                             (query - (uint8_t *) uip_appdata),
-                            &resolv_default_dns_server, UIP_HTONS(DNS_PORT));
+                            uip_nameserver_get(namemapptr->server), 
+                            UIP_HTONS(DNS_PORT));
       PRINTF("resolver: (i=%d) Sent DNS request for \"%s\".\n", i,
              namemapptr->name);
 #endif /* RESOLV_CONF_SUPPORTS_MDNS */
@@ -1041,11 +1054,28 @@ newdata(void)
     uip_ipaddr_copy(&namemapptr->ipaddr, (uip_ipaddr_t *) ans->ipaddr);
 
     resolv_found(namemapptr->name, &namemapptr->ipaddr);
+    break;
 
   skip_to_next_answer:
     queryptr = (unsigned char *)skip_name(queryptr) + 10 + uip_htons(ans->len);
     --nanswers;
   }
+
+  /* Got to this point there's no answer, try next nameserver if available
+     since this one doesn't know the answer */
+#if RESOLV_CONF_SUPPORTS_MDNS
+  if(nanswers == 0 && UIP_UDP_BUF->srcport != UIP_HTONS(MDNS_PORT) 
+      && hdr->id != 0)
+#else
+  if(nanswers == 0) 
+#endif
+  {
+    if(try_next_server(namemapptr)) {
+      namemapptr->state = STATE_ASKING;
+      process_post(&resolv_process, PROCESS_EVENT_TIMER, NULL);
+    }
+  }
+
 }
 /*---------------------------------------------------------------------------*/
 #if RESOLV_CONF_SUPPORTS_MDNS
@@ -1405,31 +1435,6 @@ resolv_lookup(const char *name, uip_ipaddr_t ** ipaddr)
   return ret;
 }
 /*---------------------------------------------------------------------------*/
-/**
- * Obtain the currently configured DNS server.
- *
- * \return A pointer to a 4-byte representation of the IP address of
- * the currently configured DNS server or NULL if no DNS server has
- * been configured.
- */
-uip_ipaddr_t *
-resolv_getserver(void)
-{
-  return &resolv_default_dns_server;
-}
-/*---------------------------------------------------------------------------*/
-/**
- * Configure a DNS server.
- *
- * \param dnsserver A pointer to a 4-byte representation of the IP
- * address of the DNS server to be configured.
- */
-void
-resolv_conf(const uip_ipaddr_t * dnsserver)
-{
-  uip_ipaddr_copy(&resolv_default_dns_server, dnsserver);
-}
-/*---------------------------------------------------------------------------*/
 /** \internal
  * Callback function which is called when a hostname is found.
  *

core/net/ip/resolv.h

@@ -57,11 +57,6 @@
  */
 CCIF extern process_event_t resolv_event_found;
 
-/* Functions. */
-CCIF void resolv_conf(const uip_ipaddr_t * dnsserver);
-
-CCIF uip_ipaddr_t *resolv_getserver(void);
-
 enum {
   /** Hostname is fresh and usable. This response is cached and will eventually
    *  expire to RESOLV_STATUS_EXPIRED.*/
@@ -95,6 +90,7 @@ enum {
 
 typedef uint8_t resolv_status_t;
 
+/* Functions. */
 CCIF resolv_status_t resolv_lookup(const char *name, uip_ipaddr_t ** ipaddr);
 
 CCIF void resolv_query(const char *name);

core/net/ip/uip-nameserver.c

@@ -0,0 +1,234 @@
+/**
+ * \addtogroup uip6
+ * @{
+ */
+
+/**
+ * \file
+ *         uIP Name Server interface
+ * \author Víctor Ariño <victor.arino@tado.com>
+ */
+
+/*
+ * Copyright (c) 2014, tado° GmbH.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ */
+
+#include "contiki.h"
+#include "contiki-net.h"
+
+#include "lib/list.h"
+#include "lib/memb.h"
+
+#include <string.h>
+/** \brief Nameserver record */
+typedef struct uip_nameserver_record {
+  struct uip_nameserver_record *next;
+  uip_ipaddr_t ip;
+  uint32_t added;
+  uint32_t lifetime;
+} uip_nameserver_record;
+
+/** \brief Initialization flag */
+static uint8_t initialized = 0;
+
+/** \name List and memory block
+ * @{
+ */
+#if UIP_NAMESERVER_POOL_SIZE > 1
+LIST(dns);
+MEMB(dnsmemb, uip_nameserver_record, UIP_NAMESERVER_POOL_SIZE);
+#else /* UIP_NAMESERVER_POOL_SIZE > 1 */
+static uip_ipaddr_t serveraddr;
+static uint32_t serverlifetime;
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+/** @} */
+
+/** \brief Expiration time in seconds */
+#define DNS_EXPIRATION(r) \
+  (((UIP_NAMESERVER_INFINITE_LIFETIME - r->added) <= r->lifetime) ? \
+   UIP_NAMESERVER_INFINITE_LIFETIME : r->added + r->lifetime)
+/*----------------------------------------------------------------------------*/
+/**
+ * Initialize the module variables
+ */
+#if UIP_NAMESERVER_POOL_SIZE > 1
+static CC_INLINE void
+init(void)
+{
+  list_init(dns);
+  memb_init(&dnsmemb);
+  initialized = 1;
+}
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+/*----------------------------------------------------------------------------*/
+void
+uip_nameserver_update(uip_ipaddr_t *nameserver, uint32_t lifetime)
+{
+#if UIP_NAMESERVER_POOL_SIZE > 1
+  register uip_nameserver_record *e;
+
+  if(initialized == 0) {
+    init();
+  }
+
+  for(e = list_head(dns); e != NULL; e = list_item_next(e)) {
+    if(uip_ipaddr_cmp(&e->ip, nameserver)) {
+      break;
+      /* RFC6106: In case there's no more space, the new servers should replace
+       *          the the eldest ones */
+    }
+  }
+  
+  if(e == NULL) {
+    if((e = memb_alloc(&dnsmemb)) != NULL) {
+      list_add(dns, e);
+    } else {
+      uip_nameserver_record *p;
+      for(e = list_head(dns), p = list_head(dns); p != NULL;
+          p = list_item_next(p)) {
+        if(DNS_EXPIRATION(p) < DNS_EXPIRATION(e)) {
+          e = p;
+        }
+      }
+    }
+  }
+
+  /* RFC6106: In case the entry is existing the expiration time must be
+   *          updated. Otherwise, new entries are added. */
+  if(e != NULL) {
+    if(lifetime == 0) {
+      memb_free(&dnsmemb, e);
+      list_remove(dns, e);
+    } else {
+      e->added = clock_seconds();
+      e->lifetime = lifetime;
+      uip_ipaddr_copy(&e->ip, nameserver);
+    }
+  }
+#else /* UIP_NAMESERVER_POOL_SIZE > 1 */
+  uip_ipaddr_copy(&serveraddr, nameserver);
+  serverlifetime = lifetime;
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+}
+/*----------------------------------------------------------------------------*/
+#if UIP_NAMESERVER_POOL_SIZE > 1
+/**
+ * Purge expired records
+ */
+static void
+purge(void)
+{
+  register uip_nameserver_record *e = NULL;
+  uint32_t time = clock_seconds();
+  for(e = list_head(dns); e != NULL; e = list_item_next(e)) {
+    if(DNS_EXPIRATION(e) < time) {
+      list_remove(dns, e);
+      memb_free(&dnsmemb, e);
+      e = list_head(dns);
+    }
+  }
+}
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+/*----------------------------------------------------------------------------*/
+uip_ipaddr_t *
+uip_nameserver_get(uint8_t num)
+{
+#if UIP_NAMESERVER_POOL_SIZE > 1
+  uint8_t i;
+  uip_nameserver_record *e = NULL;
+
+  if(initialized == 0) {
+    return NULL;
+  }
+  purge();
+  for(i = 1, e = list_head(dns); e != NULL && i <= num;
+      i++, e = list_item_next(e)) {
+  }
+
+  if(e != NULL) {
+    return &e->ip;
+  }
+  return NULL;
+#else /* UIP_NAMESERVER_POOL_SIZE > 1 */
+  if(num > 0) {
+    return NULL;
+  }
+  return &serveraddr;
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+}
+/*----------------------------------------------------------------------------*/
+uint32_t
+uip_nameserver_next_expiration(void)
+{
+#if UIP_NAMESERVER_POOL_SIZE > 1
+  register uip_nameserver_record *e = NULL;
+  uint32_t exp = UIP_NAMESERVER_INFINITE_LIFETIME;
+  uint32_t t;
+
+  if(initialized == 0 || list_length(dns) == 0) {
+    return 0;
+  }
+  purge();
+  for(e = list_head(dns); e != NULL; e = list_item_next(e)) {
+    t = DNS_EXPIRATION(e);
+    if(t < exp) {
+      exp = t;
+    }
+  }
+
+  return exp;
+#else /* UIP_NAMESERVER_POOL_SIZE > 1 */
+  return serverlifetime;
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+}
+/*----------------------------------------------------------------------------*/
+uint16_t
+uip_nameserver_count(void)
+{
+#if UIP_NAMESERVER_POOL_SIZE > 1
+  if(initialized == 0) {
+    return 0;
+  }
+  return list_length(dns);
+#else /* UIP_NAMESERVER_POOL_SIZE > 1 */
+#if NETSTACK_CONF_WITH_IPV6
+  if(uip_is_addr_unspecified(&serveraddr)) {
+#else /* NETSTACK_CONF_WITH_IPV6 */
+  if(uip_ipaddr_cmp(&serveraddr, &uip_all_zeroes_addr)) {
+#endif /* NETSTACK_CONF_WITH_IPV6 */
+    return 0;
+  } else {
+    return 1;
+  }
+#endif /* UIP_NAMESERVER_POOL_SIZE > 1 */
+}
+/*----------------------------------------------------------------------------*/
+/** @} */

core/net/ip/uip-nameserver.h

@@ -0,0 +1,101 @@
+/**
+ * \addtogroup uip6
+ * @{
+ */
+
+/**
+ * \file
+ *         uIP Name Server interface
+ * \author Víctor Ariño <victor.arino@tado.com>
+ */
+
+/*
+ * Copyright (c) 2014, tado° GmbH.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ */
+
+#ifndef UIP_NAMESERVER_H_
+#define UIP_NAMESERVER_H_
+
+/**
+ * \name General
+ * @{
+ */
+/** \brief Number of Nameservers to keep */
+#ifndef UIP_CONF_NAMESERVER_POOL_SIZE
+#define UIP_NAMESERVER_POOL_SIZE 1
+#else /* UIP_CONF_NAMESERVER_POOL_SIZE */
+#define UIP_NAMESERVER_POOL_SIZE UIP_CONF_NAMESERVER_POOL_SIZE
+#endif /* UIP_CONF_NAMESERVER_POOL_SIZE */
+/** \brief Infinite Lifetime indicator */
+#define UIP_NAMESERVER_INFINITE_LIFETIME 0xFFFFFFFF
+/** @} */
+
+/**
+ * \name Nameserver maintenance
+ * @{
+ */
+/**
+ * \brief Insert or update a nameserver into/from the pool
+ *
+ * The list is kept according to the RFC6106, which indicates that new entries
+ * will replace old ones (with lower lifetime) and existing entries will update
+ * their lifetimes.
+ *
+ * \param nameserver   Pointer to the nameserver ip address
+ * \param lifetime     Life time of the given address. Minimum is 0, which is
+ *                     considered to remove an entry. Maximum is 0xFFFFFFFF which
+ *                     is considered infinite.
+ */
+void uip_nameserver_update(uip_ipaddr_t *nameserver, uint32_t lifetime);
+
+/**
+ * \brief Get a Nameserver ip address given in RA
+ *
+ * \param num   The number of the nameserver to obtain, starting at 0 and going
+ *              up to the pool size.
+ */
+uip_ipaddr_t *uip_nameserver_get(uint8_t num);
+
+/**
+ * \brief Get next expiration time
+ *
+ * The least expiration time is returned
+ */
+uint32_t uip_nameserver_next_expiration(void);
+
+/**
+ * \brief Get the number of recorded name servers
+ */
+uint16_t uip_nameserver_count(void);
+/** @} */
+
+#endif /* UIP_NAMESERVER_H_ */
+/** @} */

core/net/ipv6/uip-nd6.c

@@ -72,6 +72,7 @@
 #include "net/ipv6/uip-icmp6.h"
 #include "net/ipv6/uip-nd6.h"
 #include "net/ipv6/uip-ds6.h"
+#include "net/ip/uip-nameserver.h"
 #include "lib/random.h"
 
 /*------------------------------------------------------------------*/
@@ -112,6 +113,7 @@ void uip_log(char *msg);
 #define UIP_ND6_OPT_HDR_BUF  ((uip_nd6_opt_hdr *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
 #define UIP_ND6_OPT_PREFIX_BUF ((uip_nd6_opt_prefix_info *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
 #define UIP_ND6_OPT_MTU_BUF ((uip_nd6_opt_mtu *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
+#define UIP_ND6_OPT_RDNSS_BUF ((uip_nd6_opt_dns *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
 /** @} */
 
 static uint8_t nd6_opt_offset;                     /** Offset from the end of the icmpv6 header to the option in uip_buf*/
@@ -715,6 +717,29 @@ uip_nd6_ra_output(uip_ipaddr_t * dest)
 
   uip_len += UIP_ND6_OPT_MTU_LEN;
   nd6_opt_offset += UIP_ND6_OPT_MTU_LEN;
+
+#if UIP_ND6_RA_RDNSS
+  if(uip_nameserver_count() > 0) {
+    uint8_t i = 0;
+    uip_ipaddr_t *ip = &UIP_ND6_OPT_RDNSS_BUF->ip;
+    uip_ipaddr_t *dns = NULL;
+    UIP_ND6_OPT_RDNSS_BUF->type = UIP_ND6_OPT_RDNSS;
+    UIP_ND6_OPT_RDNSS_BUF->reserved = 0;
+    UIP_ND6_OPT_RDNSS_BUF->lifetime = uip_nameserver_next_expiration();
+    if(UIP_ND6_OPT_RDNSS_BUF->lifetime != UIP_NAMESERVER_INFINITE_LIFETIME) {
+      UIP_ND6_OPT_RDNSS_BUF->lifetime -= clock_seconds();
+    }
+    while((dns = uip_nameserver_get(i)) != NULL) {
+      uip_ipaddr_copy(ip++, dns);
+      i++;
+    }
+    UIP_ND6_OPT_RDNSS_BUF->len = UIP_ND6_OPT_RDNSS_LEN + (i << 1);
+    PRINTF("%d nameservers reported\n", i);
+    uip_len += UIP_ND6_OPT_RDNSS_BUF->len << 3;
+    nd6_opt_offset += UIP_ND6_OPT_RDNSS_BUF->len << 3;
+  }
+#endif /* UIP_ND6_RA_RDNSS */
+
   UIP_IP_BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
   UIP_IP_BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
 
@@ -938,6 +963,23 @@ ra_input(void)
         /* End of autonomous flag related processing */
       }
       break;
+#if UIP_ND6_RA_RDNSS
+    case UIP_ND6_OPT_RDNSS:
+      if(UIP_ND6_RA_BUF->flags_reserved & (UIP_ND6_O_FLAG << 6)) {
+        PRINTF("Processing RDNSS option\n");
+        uint8_t naddr = (UIP_ND6_OPT_RDNSS_BUF->len - 1) / 2;
+        uip_ipaddr_t *ip = (uip_ipaddr_t *)(&UIP_ND6_OPT_RDNSS_BUF->ip);
+        PRINTF("got %d nameservers\n", naddr);
+        while(naddr-- > 0) {
+          PRINTF(" nameserver: ");
+          PRINT6ADDR(ip);
+          PRINTF(" lifetime: %lx\n", uip_ntohl(UIP_ND6_OPT_RDNSS_BUF->lifetime));
+          uip_nameserver_update(ip, uip_ntohl(UIP_ND6_OPT_RDNSS_BUF->lifetime));
+          ip++;
+        }
+      }
+      break;
+#endif /* UIP_ND6_RA_RDNSS */
     default:
       PRINTF("ND option not supported in RA");
       break;

core/net/ipv6/uip-nd6.h

@@ -87,7 +87,7 @@
 #define UIP_ND6_MIN_RA_INTERVAL             UIP_CONF_ND6_MIN_RA_INTERVAL
 #endif
 #define UIP_ND6_M_FLAG                      0
-#define UIP_ND6_O_FLAG                      0
+#define UIP_ND6_O_FLAG                      (UIP_ND6_RA_RDNSS || UIP_ND6_RA_DNSSL)
 #define UIP_ND6_ROUTER_LIFETIME             3 * UIP_ND6_MAX_RA_INTERVAL
 
 #define UIP_ND6_MAX_INITIAL_RA_INTERVAL     16  /*seconds*/
@@ -139,6 +139,23 @@
 /** @} */
 
 
+/** \name RFC 6106 RA DNS Options Constants  */
+/** @{ */
+#ifndef UIP_CONF_ND6_RA_RDNSS
+#define UIP_ND6_RA_RDNSS                0
+#else
+#define UIP_ND6_RA_RDNSS                UIP_CONF_ND6_RA_RDNSS
+#endif
+
+#ifndef UIP_CONF_ND6_RA_DNSSL
+#define UIP_ND6_RA_DNSSL                0
+#else
+#error Not implemented
+#define UIP_ND6_RA_DNSSL                UIP_CONF_ND6_RA_DNSSL
+#endif
+/** @} */
+
+
 /** \name ND6 option types */
 /** @{ */
 #define UIP_ND6_OPT_SLLAO               1
@@ -146,6 +163,8 @@
 #define UIP_ND6_OPT_PREFIX_INFO         3
 #define UIP_ND6_OPT_REDIRECTED_HDR      4
 #define UIP_ND6_OPT_MTU                 5
+#define UIP_ND6_OPT_RDNSS               25
+#define UIP_ND6_OPT_DNSSL               31
 /** @} */
 
 /** \name ND6 option types */
@@ -168,6 +187,8 @@
 #define UIP_ND6_OPT_HDR_LEN            2
 #define UIP_ND6_OPT_PREFIX_INFO_LEN    32
 #define UIP_ND6_OPT_MTU_LEN            8
+#define UIP_ND6_OPT_RDNSS_LEN          1
+#define UIP_ND6_OPT_DNSSL_LEN          1
 
 
 /* Length of TLLAO and SLLAO options, it is L2 dependant */
@@ -290,6 +311,15 @@ typedef struct uip_nd6_opt_mtu {
   uint32_t mtu;
 } uip_nd6_opt_mtu;
 
+/** \brief ND option RDNSS */
+typedef struct uip_nd6_opt_dns {
+  uint8_t type;
+  uint8_t len;
+  uint16_t reserved;
+  uint32_t lifetime;
+  uip_ipaddr_t ip;
+} uip_nd6_opt_dns;
+
 /** \struct Redirected header option */
 typedef struct uip_nd6_opt_redirected_hdr {
   uint8_t type;

cpu/6502/ipconfig/ipconfig.c

@@ -117,7 +117,7 @@ makestrings(void)
   makeaddr(&addr, gateway);
 
 #if WITH_DNS
-  addrptr = resolv_getserver();
+  addrptr = uip_nameserver_get(0);
   if(addrptr != NULL) {
     makeaddr(addrptr, dnsserver);
   }
@@ -245,7 +245,7 @@ dhcpc_configured(const struct dhcpc_state *s)
   uip_setnetmask(&s->netmask);
   uip_setdraddr(&s->default_router);
 #if WITH_DNS
-  resolv_conf(&s->dnsaddr);
+  uip_nameserver_update(&s->dnsaddr, UIP_NAMESERVER_INFINITE_LIFETIME);
 #endif /* WITH_DNS */
 
   set_statustext("Configured.");
@@ -261,7 +261,7 @@ dhcpc_unconfigured(const struct dhcpc_state *s)
   uip_setnetmask(&nulladdr);
   uip_setdraddr(&nulladdr);
 #if WITH_DNS
-  resolv_conf(&nulladdr);
+  uip_nameserver_update(&nulladdr, UIP_NAMESERVER_INFINITE_LIFETIME);
 #endif /* WITH_DNS */
 
   set_statustext("Unconfigured.");

cpu/6502/lib/config.c

@@ -105,7 +105,7 @@ config_read(char *filename)
   uip_setnetmask(&config.netmask);
   uip_setdraddr(&config.draddr);
 #if WITH_DNS
-  resolv_conf(&config.resolvaddr);
+  uip_nameserver_update(&config.resolvaddr, UIP_NAMESERVER_INFINITE_LIFETIME);
 #endif /* WITH_DNS */
 
   return &config.ethernetcfg;

platform/apple2enh/contiki-main.c

@@ -104,7 +104,7 @@ main(void)
     uip_setdraddr(&addr);
 
     uip_ipaddr(&addr, 192,168,0,1);
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
 
     ethernet_config = &config;
   }

platform/atarixl/contiki-main.c

@@ -100,7 +100,7 @@ main(void)
     uip_setdraddr(&addr);
 
     uip_ipaddr(&addr, 192,168,0,1);
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
 
     ethernet_config = &config;
   }

platform/c128/contiki-main.c

@@ -100,7 +100,7 @@ main(void)
     uip_setdraddr(&addr);
 
     uip_ipaddr(&addr, 192,168,0,1);
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
 
     ethernet_config = &config;
   }

platform/c64/contiki-main.c

@@ -98,7 +98,7 @@ main(void)
     uip_setdraddr(&addr);
 
     uip_ipaddr(&addr, 192,168,0,1);
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
 
     ethernet_config = &config;
   }

platform/win32/contiki-main.c

@@ -140,7 +140,7 @@ main(int argc, char **argv)
     log_message("Def. Router: ", inet_ntoa(*(struct in_addr*)&addr));
 
     uip_ipaddr(&addr, 192,168,0,1);
-    resolv_conf(&addr);
+    uip_nameserver_update(&addr, UIP_NAMESERVER_INFINITE_LIFETIME);
     log_message("DNS Server:  ", inet_ntoa(*(struct in_addr*)&addr));
   }