pkg/tinydtls: add IPv4 support

pkg/tinydtls/contrib/sock_dtls.c

@@ -114,7 +114,6 @@ static int _write(struct dtls_context_t *ctx, session_t *session, uint8_t *buf,
     sock_udp_ep_t remote;
 
     _session_to_ep(session, &remote);
-    remote.family = AF_INET6;
 
     ssize_t res = sock_udp_send(sock->udp_sock, buf, len, &remote);
 
@@ -529,15 +528,20 @@ int sock_dtls_session_init(sock_dtls_t *sock, const sock_udp_ep_t *ep,
     if (!sock->udp_sock || (sock_udp_get_local(sock->udp_sock, &local) < 0)) {
         return -EADDRNOTAVAIL;
     }
+
     if (ep->port == 0) {
         return -EINVAL;
     }
+
     switch (ep->family) {
+#ifdef SOCK_HAS_IPV4
     case AF_INET:
- #if IS_ACTIVE(SOCK_HAS_IPV6)
+        break;
+#endif
+#ifdef SOCK_HAS_IPV6
     case AF_INET6:
- #endif
         break;
+#endif
     default:
         return -EINVAL;
     }
@@ -812,24 +816,65 @@ void sock_dtls_init(void)
 static void _ep_to_session(const sock_udp_ep_t *ep, session_t *session)
 {
     session->port = ep->port;
-    session->size = sizeof(ipv6_addr_t) +       /* addr */
+    session->addr_family = ep->family;
+
+#if defined(SOCK_HAS_IPV4) && defined(SOCK_HAS_IPV6)
+    assert(sizeof(session->addr) == sizeof(ipv6_addr_t));
+#elif defined(SOCK_HAS_IPV4)
+    assert(sizeof(session->addr) == sizeof(ipv4_addr_t));
+#else
+    assert(sizeof(session->addr) == sizeof(ipv6_addr_t));
+#endif
+
+    session->size = sizeof(session->addr) +     /* addr */
                     sizeof(unsigned short);     /* port */
-    if (ipv6_addr_is_link_local((ipv6_addr_t *)ep->addr.ipv6)) {
-        /* set ifindex for link-local addresses */
-        session->ifindex = ep->netif;
-    }
-    else {
+
+    switch (ep->family) {
+#ifdef SOCK_HAS_IPV4
+    case AF_INET:
         session->ifindex = SOCK_ADDR_ANY_NETIF;
+        memcpy(&session->addr, &ep->addr.ipv4, sizeof(ipv4_addr_t));
+        break;
+#endif
+#ifdef SOCK_HAS_IPV6
+    case AF_INET6:
+        if (ipv6_addr_is_link_local((ipv6_addr_t *)ep->addr.ipv6)) {
+            /* set ifindex for link-local addresses */
+            session->ifindex = ep->netif;
+        }
+        else {
+            session->ifindex = SOCK_ADDR_ANY_NETIF;
+        }
+        memcpy(&session->addr, &ep->addr.ipv6, sizeof(ipv6_addr_t));
+        break;
+#endif
+    default:
+        assert(0);
+        return;
     }
-    memcpy(&session->addr, &ep->addr.ipv6, sizeof(ipv6_addr_t));
 }
 
 static void _session_to_ep(const session_t *session, sock_udp_ep_t *ep)
 {
     ep->port = session->port;
     ep->netif = session->ifindex;
-    ep->family = AF_INET6;
-    memcpy(&ep->addr.ipv6, &session->addr, sizeof(ipv6_addr_t));
+    ep->family = session->addr_family;
+
+    switch (session->addr_family) {
+#ifdef SOCK_HAS_IPV4
+    case AF_INET:
+        memcpy(&ep->addr.ipv4, &session->addr, sizeof(ipv4_addr_t));
+        break;
+#endif
+#ifdef SOCK_HAS_IPV6
+    case AF_INET6:
+        memcpy(&ep->addr.ipv6, &session->addr, sizeof(ipv6_addr_t));
+        break;
+#endif
+    default:
+        /* addr_family is actually ok to be 0 when coming from _copy_buffer */
+        return;
+    }
 }
 
 static inline uint32_t _update_timeout(uint32_t start, uint32_t timeout)

pkg/tinydtls/patches/0003-RIOT-OS-Add-support-for-IPv4.patch

@@ -0,0 +1,99 @@
+From e8a60987d0b0b2c0d5d7f1e44302049904789ec7 Mon Sep 17 00:00:00 2001
+From: HendrikVE <hendrik1995@msn.com>
+Date: Sun, 6 Mar 2022 00:17:12 +0100
+Subject: [PATCH] RIOT OS: Add support for IPv4
+
+---
+ session.c | 38 +++++++++++++++++++++++++++++++++-----
+ session.h | 16 ++++++++++++++--
+ 2 files changed, 47 insertions(+), 7 deletions(-)
+
+diff --git a/session.c b/session.c
+index 8e9f544..dea8990 100644
+--- a/session.c
++++ b/session.c
+@@ -32,11 +32,23 @@
+    && uip_ipaddr_cmp(&((A)->addr),&((B)->addr))			\
+    && (A)->ifindex == (B)->ifindex)
+ #elif defined(WITH_RIOT)
+-#define _dtls_address_equals_impl(A,B)                          \
+-  ((A)->size == (B)->size                                       \
+-   && (A)->port == (B)->port                                    \
+-   && ipv6_addr_equal(&((A)->addr),&((B)->addr))                \
+-   && (A)->ifindex == (B)->ifindex)
++  #include "net/af.h"
++  #ifdef SOCK_HAS_IPV4
++  #define _dtls_ipv4_address_equals_impl(A,B)                   \
++    ((A)->size == (B)->size                                     \
++     && (A)->port == (B)->port                                  \
++     && (A)->ifindex == (B)->ifindex)                           \
++     && (A)->addr_family == (B)->addr_family                    \
++     && ipv4_addr_equal(&((A)->addr.ipv4),&((B)->addr.ipv4))
++  #endif
++  #ifdef SOCK_HAS_IPV6
++  #define _dtls_ipv6_address_equals_impl(A,B)                   \
++    ((A)->size == (B)->size                                     \
++     && (A)->port == (B)->port                                  \
++     && (A)->ifindex == (B)->ifindex)                           \
++     && (A)->addr_family == (B)->addr_family                    \
++     && ipv6_addr_equal(&((A)->addr.ipv6),&((B)->addr.ipv6))
++  #endif
+ #else /* WITH_CONTIKI */
+
+ static inline int 
+@@ -120,5 +132,21 @@ dtls_session_addr(session_t *sess, socklen_t *addrlen) {
+ int
+ dtls_session_equals(const session_t *a, const session_t *b) {
+   assert(a); assert(b);
++#ifdef RIOT_VERSION
++  switch (a->addr_family) {
++  #ifdef SOCK_HAS_IPV4
++  case AF_INET:
++    return _dtls_ipv4_address_equals_impl(a, b);
++  #endif
++  #ifdef SOCK_HAS_IPV6
++  case AF_INET6:
++    return _dtls_ipv6_address_equals_impl(a, b);
++  #endif
++  default:
++    assert(0);
++    return false;
++  }
++#else
+   return _dtls_address_equals_impl(a, b);
++#endif /* RIOT_VERSION */
+ }
+diff --git a/session.h b/session.h
+index 8ba5fa2..b90b269 100644
+--- a/session.h
++++ b/session.h
+@@ -32,12 +32,24 @@ typedef struct {
+ } session_t;
+  /* TODO: Add support for RIOT over sockets  */
+ #elif defined(WITH_RIOT)
++#include "net/ipv4/addr.h"
+ #include "net/ipv6/addr.h"
+ typedef struct {
+   unsigned char size;
+-  ipv6_addr_t addr;
+-  unsigned short port;
+   int ifindex;
++  int addr_family;
++  union {
++  #ifdef SOCK_HAS_IPV4
++    ipv4_addr_t ipv4;
++  #endif
++  #ifdef SOCK_HAS_IPV6
++    ipv6_addr_t ipv6;
++  #endif
++  } addr;
++  /* Note: Member "port" MUST follow directly after the member "addr"! dtls_hmac_update in
++   *       dtls.c gets "session->size" as length input which is set to e.g.
++   *       "sizeof(ipv6_addr_t) + sizeof(unsigned short)" = (addr + port) in sock_dtls.c */
++  unsigned short port;
+ } session_t;
+ #else /* ! WITH_CONTIKI && ! WITH_RIOT */
+
+-- 
+2.25.1
+