Compile with -std=c99 and restructure some code to ensure there is no invalid aliasing (hopefully)

1 files changed, 8 insertions, 5 deletions

diff --git a/src/send.c b/src/send.c
index caaa9f6..9f76d31 100644
--- a/src/send.c
+++ b/src/send.c
@@ -42,8 +42,9 @@ static inline void add_pktinfo(struct msghdr *msg, const fastd_peer_address_t *l
 
 		msg->msg_controllen += cmsg->cmsg_len;
 
-		struct in_pktinfo *pktinfo = (struct in_pktinfo*)CMSG_DATA(cmsg);
-		pktinfo->ipi_spec_dst = local_addr->in.sin_addr;
+		struct in_pktinfo pktinfo = {};
+		pktinfo.ipi_spec_dst = local_addr->in.sin_addr;
+		memcpy(CMSG_DATA(cmsg), &pktinfo, sizeof(pktinfo));
 		return;
 	}
 #endif
@@ -55,11 +56,13 @@ static inline void add_pktinfo(struct msghdr *msg, const fastd_peer_address_t *l
 
 		msg->msg_controllen += cmsg->cmsg_len;
 
-		struct in6_pktinfo *pktinfo = (struct in6_pktinfo*)CMSG_DATA(cmsg);
-		pktinfo->ipi6_addr = local_addr->in6.sin6_addr;
+		struct in6_pktinfo pktinfo = {};
+		pktinfo.ipi6_addr = local_addr->in6.sin6_addr;
 
 		if (IN6_IS_ADDR_LINKLOCAL(&local_addr->in6.sin6_addr))
-			pktinfo->ipi6_ifindex = local_addr->in6.sin6_scope_id;
+			pktinfo.ipi6_ifindex = local_addr->in6.sin6_scope_id;
+
+		memcpy(CMSG_DATA(cmsg), &pktinfo, sizeof(pktinfo));
 	}
 }