7.0 refactor

src/sntp.c

@@ -0,0 +1,69 @@
+#include "sntp.h"
+#include "arch.h"
+#include "event.h"
+#include "log.h"
+#include "util.h"
+
+#define SNTP_INTERVAL_SEC (3600)
+#define SNTP_TIME_OFFSET 2208988800
+
+static unsigned long s_sntmp_next;
+
+int mg_sntp_parse(const unsigned char *buf, size_t len, struct timeval *tv) {
+  int mode = buf[0] & 7, res = -1;
+  if (len < 48) {
+    LOG(LL_ERROR, ("%s", "corrupt packet"));
+  } else if ((buf[0] & 0x38) >> 3 != 4) {
+    LOG(LL_ERROR, ("%s", "wrong version"));
+  } else if (mode != 4 && mode != 5) {
+    LOG(LL_ERROR, ("%s", "not a server reply"));
+  } else if (buf[1] == 0) {
+    LOG(LL_ERROR, ("%s", "server sent a kiss of death"));
+  } else {
+    uint32_t *data = (uint32_t *) &buf[40];
+    tv->tv_sec = mg_ntohl(data[0]) - SNTP_TIME_OFFSET;
+    tv->tv_usec = mg_ntohl(data[1]);
+    s_sntmp_next = tv->tv_sec + SNTP_INTERVAL_SEC;
+    res = 0;
+  }
+  return res;
+}
+
+static void sntp_cb(struct mg_connection *c, int ev, void *evd, void *fnd) {
+  if (ev == MG_EV_READ) {
+    struct timeval tv = {0, 0};
+    if (mg_sntp_parse(c->recv.buf, c->recv.len, &tv) == 0) {
+      mg_call(c, MG_EV_SNTP_TIME, &tv);
+      LOG(LL_DEBUG, ("%u.%u, next at %lu", (unsigned) tv.tv_sec,
+                     (unsigned) tv.tv_usec, s_sntmp_next));
+    }
+    c->recv.len = 0;  // Clear receive buffer
+  } else if (ev == MG_EV_RESOLVE) {
+    mg_sntp_send(c, time(NULL));
+  } else if (ev == MG_EV_CLOSE) {
+    // mg_fn_del(c, sntp_cb);
+  }
+  (void) fnd;
+  (void) evd;
+}
+
+void mg_sntp_send(struct mg_connection *c, unsigned long utc) {
+  if (c->is_resolving) {
+    LOG(LL_ERROR, ("%p wait until resolved", c->fd));
+  } else if (utc > s_sntmp_next) {
+    uint8_t buf[48] = {0};
+    s_sntmp_next = utc + SNTP_INTERVAL_SEC;
+    buf[0] = (3 << 6) | (4 << 3) | 3;
+    mg_send(c, buf, sizeof(buf));
+    LOG(LL_DEBUG,
+        ("%p request sent, ct %lu, next at %lu", c->fd, utc, s_sntmp_next));
+  }
+}
+
+struct mg_connection *mg_sntp_connect(struct mg_mgr *mgr, const char *url,
+                                      mg_event_handler_t fn, void *fnd) {
+  struct mg_connection *c = NULL;
+  if (url == NULL) url = "udp://time.google.com:123";
+  if ((c = mg_connect(mgr, url, fn, fnd)) != NULL) c->pfn = sntp_cb;
+  return c;
+}