From 0ef62b9690ee09b559e09a5235c5c7bbf0ecea5c Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Mon, 26 Feb 2018 17:34:43 +0100
Subject: [PATCH] gnrc_ndp: add support for building RDNSS option
---
Makefile.dep | 7 +++++++
makefiles/pseudomodules.inc.mk | 1 +
sys/include/net/gnrc/ipv6/nib/conf.h | 13 +++++++++++++
sys/include/net/gnrc/ndp.h | 23 +++++++++++++++++++++++
sys/net/gnrc/network_layer/ndp/gnrc_ndp.c | 21 +++++++++++++++++++++
5 files changed, 65 insertions(+)
diff --git a/Makefile.dep b/Makefile.dep
index 0d1751434a..9237561036 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -305,6 +305,10 @@ ifneq (,$(filter gnrc_ipv6_nib_6ln,$(USEMODULE)))
USEMODULE += gnrc_sixlowpan_nd
endif
+ifneq (,$(filter gnrc_ipv6_nib_dns,$(USEMODULE)))
+ USEMODULE += gnrc_ipv6_nib
+endif
+
ifneq (,$(filter gnrc_ipv6_nib_router,$(USEMODULE)))
USEMODULE += gnrc_ipv6_nib
endif
@@ -315,6 +319,9 @@ ifneq (,$(filter gnrc_ipv6_nib,$(USEMODULE)))
USEMODULE += gnrc_netif
USEMODULE += ipv6_addr
USEMODULE += random
+ ifneq (,$(filter sock_dns,$(USEMODULE)))
+ USEMODULE += gnrc_ipv6_nib_dns
+ endif
endif
ifneq (,$(filter gnrc_udp,$(USEMODULE)))
diff --git a/makefiles/pseudomodules.inc.mk b/makefiles/pseudomodules.inc.mk
index 1b4ca0337e..dca9b530d0 100644
--- a/makefiles/pseudomodules.inc.mk
+++ b/makefiles/pseudomodules.inc.mk
@@ -17,6 +17,7 @@ PSEUDOMODULES += gnrc_ipv6_router_default
PSEUDOMODULES += gnrc_ipv6_nib_6lbr
PSEUDOMODULES += gnrc_ipv6_nib_6ln
PSEUDOMODULES += gnrc_ipv6_nib_6lr
+PSEUDOMODULES += gnrc_ipv6_nib_dns
PSEUDOMODULES += gnrc_ipv6_nib_router
PSEUDOMODULES += gnrc_netdev_default
PSEUDOMODULES += gnrc_neterr
diff --git a/sys/include/net/gnrc/ipv6/nib/conf.h b/sys/include/net/gnrc/ipv6/nib/conf.h
index a62c4b47d0..d859428782 100644
--- a/sys/include/net/gnrc/ipv6/nib/conf.h
+++ b/sys/include/net/gnrc/ipv6/nib/conf.h
@@ -68,6 +68,10 @@ extern "C" {
#define GNRC_IPV6_NIB_CONF_ROUTER (1)
#endif
+#ifdef MODULE_GNRC_IPV6_NIB_DNS
+#define GNRC_IPV6_NIB_CONF_DNS (1)
+#endif
+
/**
* @name Compile flags
* @brief Compile flags to (de-)activate certain features for NIB
@@ -171,6 +175,15 @@ extern "C" {
#endif
#endif
+/**
+ * @brief Support for DNS configuration options
+ *
+ * @see [RFC 8106](https://tools.ietf.org/html/rfc8106)
+ */
+#ifndef GNRC_IPV6_NIB_CONF_DNS
+#define GNRC_IPV6_NIB_CONF_DNS (0)
+#endif
+
/**
* @brief Multihop prefix and 6LoWPAN context distribution
*
diff --git a/sys/include/net/gnrc/ndp.h b/sys/include/net/gnrc/ndp.h
index 660f47646f..94aff38982 100644
--- a/sys/include/net/gnrc/ndp.h
+++ b/sys/include/net/gnrc/ndp.h
@@ -250,6 +250,29 @@ gnrc_pktsnip_t *gnrc_ndp_opt_pi_build(const ipv6_addr_t *prefix,
*/
gnrc_pktsnip_t *gnrc_ndp_opt_mtu_build(uint32_t mtu, gnrc_pktsnip_t *next);
+/**
+ * @brief Builts the recursive DNS server option
+ *
+ * @see [RFC 8106, section 5.1](https://tools.ietf.org/html/rfc8106#section-5.1)
+ * @pre `addrs != NULL`
+ * @pre `addrs_num > 0`
+ *
+ * @note Should only be used with router advertisemnents. This is not checked
+ * however, since nodes should silently ignore it in other NDP messages.
+ *
+ * @param[in] lifetime The lifetime of the recursive DNS servers
+ * @param[in] addrs The addresses of the recursive DNS servers
+ * @param[in] addrs_num The number of addresses in @p addrs
+ * @param[in] next More options in the packet. NULL, if there are none.
+ *
+ * @return The packet snip list of options, on success
+ * @return @p next, if RDNSS is not supported
+ * @return NULL, if packet buffer is full
+ */
+gnrc_pktsnip_t *gnrc_ndp_opt_rdnss_build(uint32_t lifetime, ipv6_addr_t *addrs,
+ unsigned addrs_num,
+ gnrc_pktsnip_t *next);
+
/**
* @brief Send pre-compiled neighbor solicitation depending on a given network
* interface.
diff --git a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
index afce23dac9..e467ea9506 100644
--- a/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
+++ b/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c
@@ -222,6 +222,27 @@ gnrc_pktsnip_t *gnrc_ndp_opt_mtu_build(uint32_t mtu, gnrc_pktsnip_t *next)
return pkt;
}
+gnrc_pktsnip_t *gnrc_ndp_opt_rdnss_build(uint32_t ltime, ipv6_addr_t *addrs,
+ unsigned addrs_num,
+ gnrc_pktsnip_t *next)
+{
+ assert(addrs != NULL);
+ assert(addrs_num > 0);
+ size_t opt_size = sizeof(ndp_opt_t) + (sizeof(ipv6_addr_t) * addrs_num);
+ gnrc_pktsnip_t *pkt = gnrc_ndp_opt_build(NDP_OPT_RDNSS, opt_size, next);
+
+ if (pkt != NULL) {
+ ndp_opt_rdnss_t *rdnss_opt = pkt->data;
+ rdnss_opt->resv.u16 = 0;
+ rdnss_opt->ltime = byteorder_htonl(ltime);
+ for (unsigned i = 0; i < addrs_num; i++) {
+ memcpy(&rdnss_opt->addrs[i], &addrs[i],
+ sizeof(rdnss_opt->addrs[i]));
+ }
+ }
+ return pkt;
+}
+
static gnrc_pktsnip_t *_build_headers(gnrc_netif_t *netif,
const ipv6_addr_t *src,
const ipv6_addr_t *dst,
--
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