1 files changed, 57 insertions, 0 deletions
diff --git a/recvfrom_timestamped.c b/recvfrom_timestamped.c
new file mode 100644
index 0000000..6dd43b0
--- /dev/null
+++ b/recvfrom_timestamped.c
@@ -0,0 +1,57 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+
+
+ssize_t
+libsimple_recvfrom_timestamped(int fd, void *restrict buf, size_t n, int flags, struct sockaddr *restrict addr,
+                               socklen_t addrlen, struct timespec *restrict ts)
+{
+	struct iovec iov;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	char cms[CMSG_SPACE(sizeof(*ts))];
+	size_t r;
+
+	iov.iov_base = buf;
+	iov.iov_len = n;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_name = addr;
+	msg.msg_namelen = addrlen;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+
+	msg.msg_control = (caddr_t)cms;
+	msg.msg_controllen = sizeof(cms);
+
+	switch ((r = recvmsg(fd, &msg, flags))) {
+	case -1:
+		return -1;
+	case 0:
+	       	errno = ECONNRESET;
+		return -1;
+	default:
+		break;
+	}
+
+	if (!ts)
+		return r;
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (cmsg &&
+	    cmsg->cmsg_level == SOL_SOCKET &&
+	    cmsg->cmsg_type  == SCM_TIMESTAMPNS &&
+	    cmsg->cmsg_len   == CMSG_LEN(sizeof(*ts))) {
+		memcpy(ts, CMSG_DATA(cmsg), sizeof(*ts));
+	} else if (cmsg &&
+	           cmsg->cmsg_level == SOL_SOCKET &&
+	           cmsg->cmsg_type  == SCM_TIMESTAMP &&
+	           cmsg->cmsg_len   == CMSG_LEN(sizeof(*ts))) {
+		memcpy(ts, CMSG_DATA(cmsg), sizeof(*ts));
+		ts->tv_nsec *= 1000;
+	} else {
+		memset(ts, 0, sizeof(*ts));
+	}
+
+	return r;
+}