1 files changed, 65 insertions, 0 deletions
diff --git a/toys/pending/sntp.c b/toys/pending/sntp.c
new file mode 100644
index 00000000..f34c3da2
--- /dev/null
+++ b/toys/pending/sntp.c
@@ -0,0 +1,65 @@
+/* sntp.c - sntp client and server
+ *
+ * Copyright 2019 Rob Landley <rob@landley.net>
+ *
+ * See https://www.ietf.org/rfc/rfc4330.txt
+
+USE_SNTP(NEWTOY(sntp, "<1", TOYFLAG_USR|TOYFLAG_BIN))
+
+config SNTP
+  bool "sntp"
+  default n
+  help
+    usage: sntp SERVER...
+
+    Simple Network Time Protocol client, set system clock from a server.
+*/
+
+#define FOR_sntp
+#include "toys.h"
+
+GLOBALS(
+  int unused;
+)
+
+union socksaddr {
+  struct sockaddr_in in;
+  struct sockaddr_in6 in6;
+};
+
+// timeout in milliseconds
+int xrecvwait(int fd, char *buf, int len, union socksaddr *sa, int timeout)
+{
+  socklen_t sl = sizeof(*sa);
+
+  if (timeout >= 0) {
+    struct pollfd pfd;
+
+    pfd.fd = fd;
+    pfd.events = POLLIN;
+    if (!xpoll(&pfd, 1, timeout)) return 0;
+  }
+
+  len = recvfrom(fd, buf, len, 0, (void *)sa, &sl);
+  if (len<0) perror_exit("recvfrom");
+
+  return len;
+}
+
+void sntp_main(void)
+{
+  struct addrinfo *ai;
+  union socksaddr sa;
+  int fd, len;
+
+  ai = xgetaddrinfo(*toys.optargs, 0, AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, 0);
+  // When root, bind to local server address
+  if (!getuid())
+    fd = xbind(xgetaddrinfo("", "123", AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, 0));
+  else fd = xsocket(ai->ai_family, SOCK_DGRAM, IPPROTO_UDP);
+
+  xsendto(fd, toybuf, 48, ai->ai_addr);
+  len = xrecvwait(fd, toybuf, sizeof(toybuf), &sa, 5000);
+  printf("%d\n", len);
+  if (len>0) write(1, toybuf, len);
+}