Add a "fork" of musl as //fusl.

fusl/src/network/sendmsg.c

Index: fusl/src/network/sendmsg.c
diff --git a/fusl/src/network/sendmsg.c b/fusl/src/network/sendmsg.c
new file mode 100644
index 0000000000000000000000000000000000000000..5f080007bf90e54a98ca25fbe7766ee51313a7eb
--- /dev/null
+++ b/fusl/src/network/sendmsg.c
@@ -0,0 +1,30 @@
+#include <sys/socket.h>
+#include <limits.h>
+#include <string.h>
+#include <errno.h>
+#include "syscall.h"
+#include "libc.h"
+
+ssize_t sendmsg(int fd, const struct msghdr *msg, int flags)
+{
+#if LONG_MAX > INT_MAX
+	struct msghdr h;
+	struct cmsghdr chbuf[1024/sizeof(struct cmsghdr)+1], *c;
+	if (msg) {
+		h = *msg;
+		h.__pad1 = h.__pad2 = 0;
+		msg = &h;
+		if (h.msg_controllen) {
+			if (h.msg_controllen > 1024) {
+				errno = ENOMEM;
+				return -1;
+			}
+			memcpy(chbuf, h.msg_control, h.msg_controllen);
+			h.msg_control = chbuf;
+			for (c=CMSG_FIRSTHDR(&h); c; c=CMSG_NXTHDR(&h,c))
+				c->__pad1 = 0;
+		}
+	}
+#endif
+	return socketcall_cp(sendmsg, fd, msg, flags, 0, 0, 0);
+}