From b366e59c87aa03c0a9c63625a4df922ac70abc94 Mon Sep 17 00:00:00 2001
From: Oleg Hahm <oleg@hobbykeller.org>
Date: Wed, 2 Dec 2015 14:20:44 +0100
Subject: [PATCH] conn: add function to find the best source address
...and use it in POSIX sendto() function.
---
sys/include/net/conn.h | 14 ++++++++++++++
sys/net/gnrc/conn/gnrc_conn.c | 8 ++++++++
sys/posix/sockets/posix_sockets.c | 14 ++++++++++----
3 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/sys/include/net/conn.h b/sys/include/net/conn.h
index bd03991973..8e5a45a776 100644
--- a/sys/include/net/conn.h
+++ b/sys/include/net/conn.h
@@ -31,6 +31,7 @@
* @brief Application connection API definitions
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
+ * @author Oliver Hahm <oliver.hahm@inria.fr>
*/
#ifndef NET_CONN_H_
#define NET_CONN_H_
@@ -38,11 +39,24 @@
#include "net/conn/ip.h"
#include "net/conn/tcp.h"
#include "net/conn/udp.h"
+#include "net/ipv6/addr.h"
#ifdef __cplusplus
extern "C" {
#endif
+/**
+ * @brief Find the best matching source address for a given prefix
+ *
+ * @param[in] dst Pointer to the IPv6 address to find a match for
+ * Must not be NULL
+ *
+ * @return NULL if no matching address on any interface could be found
+ * @return pointer to an IPv6 address configured on an interface with the best
+ * match to @p dst
+ */
+ipv6_addr_t *conn_find_best_source(const ipv6_addr_t *dst);
+
#ifdef __cplusplus
}
#endif
diff --git a/sys/net/gnrc/conn/gnrc_conn.c b/sys/net/gnrc/conn/gnrc_conn.c
index 9a835965bb..80fe1c9481 100644
--- a/sys/net/gnrc/conn/gnrc_conn.c
+++ b/sys/net/gnrc/conn/gnrc_conn.c
@@ -11,6 +11,7 @@
*
* @file
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
+ * @author Oliver Hahm <oliver.hahm@inria.fr>
*/
#include "net/conn.h"
@@ -85,6 +86,13 @@ bool gnrc_conn6_set_local_addr(uint8_t *conn_addr, const ipv6_addr_t *addr)
}
return true;
}
+
+ipv6_addr_t *conn_find_best_source(const ipv6_addr_t *dst)
+{
+ ipv6_addr_t *local = NULL;
+ gnrc_ipv6_netif_find_by_prefix(&local, dst);
+ return local;
+}
#endif
/** @} */
diff --git a/sys/posix/sockets/posix_sockets.c b/sys/posix/sockets/posix_sockets.c
index 623283e636..d01466dc90 100644
--- a/sys/posix/sockets/posix_sockets.c
+++ b/sys/posix/sockets/posix_sockets.c
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2015 Freie Universität Berlin
+ * Copyright (C) 2015 INRIA
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
@@ -11,6 +12,7 @@
* @file
* @brief Providing implementation for POSIX socket wrapper.
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
+ * @author Oliver Hahm <oliver.hahm@inria.fr>
* @todo
*/
@@ -862,11 +864,15 @@ ssize_t sendto(int socket, const void *buffer, size_t length, int flags,
sport, byteorder_ntohs(port));
}
else if (address != NULL) {
- ipv6_addr_t local;
+ ipv6_addr_t unspec;
+ ipv6_addr_t *best_match;
s->src_port = (uint16_t)genrand_uint32_range(1LU << 10U, 1LU << 16U);
- /* implicitly bind the socket here */
- ipv6_addr_set_unspecified(&local);
- if ((res = conn_udp_create(&s->conn.udp, &local, sizeof(local),
+ /* find the best matching source address */
+ if ((best_match = conn_find_best_source(addr)) == NULL) {
+ ipv6_addr_set_unspecified(&unspec);
+ best_match = &unspec;
+ }
+ if ((res = conn_udp_create(&s->conn.udp, best_match, sizeof(unspec),
s->domain, s->src_port)) < 0) {
errno = -res;
return -1;
--
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