diff --git a/CHANGELOG b/CHANGELOG
index b2cb7e90..d61ff15b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,6 +6,11 @@ HISTORY
 
   ++ New features:
 
+  2015-08-30: Simon Goldschmidt
+  * support IPv4 source based routing: define LWIP_HOOK_IP4_ROUTE_SRC to point
+    to a routing function
+
+
   2015-08-05: Simon Goldschmidt
   * many files: allow multicast socket options IP_MULTICAST_TTL, IP_MULTICAST_IF
     and IP_MULTICAST_LOOP to be used without IGMP
diff --git a/src/core/ipv4/ip4.c b/src/core/ipv4/ip4.c
index d1c47f11..ebe066d3 100644
--- a/src/core/ipv4/ip4.c
+++ b/src/core/ipv4/ip4.c
@@ -113,6 +113,24 @@ ip4_set_default_multicast_netif(struct netif* default_multicast_netif)
 }
 #endif /* LWIP_MULTICAST_TX_OPTIONS */
 
+#ifdef LWIP_HOOK_IP4_ROUTE_SRC
+/**
+ * Source based IPv4 routing must be fully implemented in
+ * LWIP_HOOK_IP4_ROUTE_SRC(). This function only provides he parameters.
+ */
+struct netif *
+ip4_route_src(const ip4_addr_t *dest, const ip4_addr_t *src)
+{
+  if (src != NULL) {
+    struct netif *netif = LWIP_HOOK_IP4_ROUTE_SRC(dest, src);
+    if (netif != NULL) {
+      return netif;
+    }
+  }
+  return ip4_route(dest);
+}
+#endif /* LWIP_HOOK_IP4_ROUTE_SRC */
+
 /**
  * Finds the appropriate network interface for a given IP address. It
  * searches the list of network interfaces linearly. A match is found
@@ -127,7 +145,12 @@ ip4_route(const ip4_addr_t *dest)
 {
   struct netif *netif;
 
-#ifdef LWIP_HOOK_IP4_ROUTE
+#ifdef LWIP_HOOK_IP4_ROUTE_SRC
+  netif = LWIP_HOOK_IP4_ROUTE_SRC(dest, NULL);
+  if (netif != NULL) {
+    return netif;
+  }
+#elif defined(LWIP_HOOK_IP4_ROUTE)
   netif = LWIP_HOOK_IP4_ROUTE(dest);
   if (netif != NULL) {
     return netif;
@@ -253,7 +276,7 @@ ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
   }
 
   /* Find network interface where to forward this IP packet to. */
-  netif = ip4_route(ip4_current_dest_addr());
+  netif = ip4_route_src(ip4_current_dest_addr(), ip4_current_src_addr());
   if (netif == NULL) {
     LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
       ip4_addr1_16(ip4_current_dest_addr()), ip4_addr2_16(ip4_current_dest_addr()),
@@ -937,7 +960,7 @@ ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
 
   LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
 
-  if ((netif = ip4_route(dest)) == NULL) {
+  if ((netif = ip4_route_src(dest, src)) == NULL) {
     LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
       ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
     IP_STATS_INC(ip.rterr);
@@ -975,7 +998,7 @@ ip4_output_hinted(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
 
   LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX(p);
 
-  if ((netif = ip4_route(dest)) == NULL) {
+  if ((netif = ip4_route_src(dest, src)) == NULL) {
     LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
       ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
     IP_STATS_INC(ip.rterr);
diff --git a/src/core/tcp.c b/src/core/tcp.c
index 6edab081..188bcf80 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -1788,12 +1788,12 @@ tcp_next_iss(void)
  */
 u16_t
 tcp_eff_send_mss_impl(u16_t sendmss, const ip_addr_t *dest
-#if LWIP_IPV6
+#if LWIP_IPV6 || LWIP_IPV4_SRC_ROUTING
                      , const ip_addr_t *src
-#if LWIP_IPV4
+#endif /* LWIP_IPV6 || LWIP_IPV4_SRC_ROUTING */
+#if LWIP_IPV6 && LWIP_IPV4
                      , u8_t isipv6
-#endif /* LWIP_IPV4 */
-#endif /* LWIP_IPV6 */
+#endif /* LWIP_IPV6 && LWIP_IPV4 */
                      )
 {
   u16_t mss_s;
diff --git a/src/include/lwip/ip.h b/src/include/lwip/ip.h
index 92ecb8f0..f43b5ec9 100644
--- a/src/include/lwip/ip.h
+++ b/src/include/lwip/ip.h
@@ -262,7 +262,7 @@ extern struct ip_globals ip_data;
 #define ip_route(isipv6, src, dest) \
         ((isipv6) ? \
         ip6_route(ip_2_ip6(src), ip_2_ip6(dest)) : \
-        ip4_route(ip_2_ip4(dest)))
+        ip4_route_src(ip_2_ip4(dest), ip_2_ip4(src)))
 #define ip_netif_get_local_ip(isipv6, netif, dest, storage) ((isipv6) ? \
         ip6_2_ip(ip6_netif_get_local_ip(netif, ip_2_ip6(dest)), storage) : \
         ip4_2_ip(ip4_netif_get_local_ip(netif), storage))
@@ -278,7 +278,7 @@ err_t ip_input(struct pbuf *p, struct netif *inp);
 #define ip_output_hinted(isipv6, p, src, dest, ttl, tos, proto, addr_hint) \
         ip4_output_hinted(p, src, dest, ttl, tos, proto, addr_hint)
 #define ip_route(isipv6, src, dest) \
-        ip4_route(dest)
+        ip4_route_src(dest, src)
 #define ip_netif_get_local_ip(isipv6, netif, dest, storage) \
         ip4_netif_get_local_ip(netif)
 #define ip_debug_print(is_ipv6, p) ip4_debug_print(p)
diff --git a/src/include/lwip/ip4.h b/src/include/lwip/ip4.h
index 2447e250..8a06c4e6 100644
--- a/src/include/lwip/ip4.h
+++ b/src/include/lwip/ip4.h
@@ -47,6 +47,12 @@
 extern "C" {
 #endif
 
+#ifdef LWIP_HOOK_IP4_ROUTE_SRC
+#define LWIP_IPV4_SRC_ROUTING   1
+#else
+#define LWIP_IPV4_SRC_ROUTING   0
+#endif
+
 /** Currently, the function ip_output_if_opt() is only used with IGMP */
 #define IP_OPTIONS_SEND   (LWIP_IPV4 && LWIP_IGMP)
 
@@ -108,6 +114,11 @@ PACK_STRUCT_END
 
 #define ip_init() /* Compatibility define, no init needed. */
 struct netif *ip4_route(const ip4_addr_t *dest);
+#if LWIP_IPV4_SRC_ROUTING
+struct netif *ip4_route_src(const ip4_addr_t *dest, const ip4_addr_t *src);
+#else /* LWIP_IPV4_SRC_ROUTING */
+#define ip4_route_src(dest, src) ip4_route(dest)
+#endif /* LWIP_IPV4_SRC_ROUTING */
 err_t ip4_input(struct pbuf *p, struct netif *inp);
 err_t ip4_output(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest,
        u8_t ttl, u8_t tos, u8_t proto);
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 359a0c26..4e1588a1 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -2767,6 +2767,11 @@
  * that case, ip_route() continues as normal.
  */
 
+/**
+ * LWIP_HOOK_IP4_ROUTE_SRC(dest, src):
+ * - source-based routing for IPv4 (see LWIP_HOOK_IP4_ROUTE(), src may be NULL)
+ */
+
 /**
  * LWIP_HOOK_ETHARP_GET_GW(netif, dest):
  * - called from etharp_output() (IPv4)
diff --git a/src/include/lwip/tcp_impl.h b/src/include/lwip/tcp_impl.h
index 51401223..8c53cc47 100644
--- a/src/include/lwip/tcp_impl.h
+++ b/src/include/lwip/tcp_impl.h
@@ -494,16 +494,16 @@ void  tcp_trigger_input_pcb_close(void);
 
 #if TCP_CALCULATE_EFF_SEND_MSS
 u16_t tcp_eff_send_mss_impl(u16_t sendmss, const ip_addr_t *dest
-#if LWIP_IPV6
+#if LWIP_IPV6 || LWIP_IPV4_SRC_ROUTING
                            , const ip_addr_t *src
-#if LWIP_IPV4
+#endif /* LWIP_IPV6 || LWIP_IPV4_SRC_ROUTING */
+#if LWIP_IPV6 && LWIP_IPV4
                            , u8_t isipv6
-#endif /* LWIP_IPV4 */
-#endif /* LWIP_IPV6 */
+#endif /* LWIP_IPV6 && LWIP_IPV4 */
                            );
 #if LWIP_IPV4 && LWIP_IPV6
 #define tcp_eff_send_mss(sendmss, src, dest, isipv6) tcp_eff_send_mss_impl(sendmss, dest, src, isipv6)
-#elif LWIP_IPV6
+#elif LWIP_IPV6 || LWIP_IPV4_SRC_ROUTING
 #define tcp_eff_send_mss(sendmss, src, dest, isipv6) tcp_eff_send_mss_impl(sendmss, dest, src)
 #else /* LWIP_IPV4 && LWIP_IPV6 */
 #define tcp_eff_send_mss(sendmss, src, dest, isipv6) tcp_eff_send_mss_impl(sendmss, dest)