Fix SSL creds file watching on kevent platforms (BSDs) for symlinks

[exim.git] / src / src / tls.c

diff --git a/src/src/tls.c b/src/src/tls.c
index 5adab7c7bcad1646841825b25f0b28ef6f992916..3de417eca0498ca710ab178eb3f52642ffa3e8e4 100644 (file)
--- a/src/src/tls.c
+++ b/src/src/tls.c
@@ -38,7 +38,7 @@ functions from the OpenSSL or GNU TLS libraries. */
 
 static void tls_per_lib_daemon_init(void);
 static void tls_per_lib_daemon_tick(void);
-static void tls_server_creds_init(void);
+static unsigned  tls_server_creds_init(void);
 static void tls_server_creds_invalidate(void);
 static void tls_client_creds_init(transport_instance *, BOOL);
 static void tls_client_creds_invalidate(transport_instance *);
@@ -82,6 +82,8 @@ static struct kevent kev[KEV_SIZE];
 static int kev_used = 0;
 #endif
 
+static unsigned tls_creds_expire = 0;
+
 /*************************************************
 *       Expand string; give error on failure     *
 *************************************************/
@@ -156,9 +158,13 @@ return FALSE;
 # endif
 # ifdef EXIM_HAVE_KEVENT
 {
-uschar * s;
-int fd1, fd2, i, cnt = 0;
+uschar * s, * t;
+int fd1, fd2, i, j, cnt = 0;
 struct stat sb;
+#ifdef OpenBSD
+struct kevent k_dummy;
+struct timespec ts = {0};
+#endif
 
 errno = 0;
 if (Ustrcmp(filename, "system,cache") == 0) return TRUE;
@@ -203,15 +209,23 @@ for (;;)
 
   if (!(S_ISLNK(sb.st_mode))) break;
 
-  s = store_get(1024, FALSE);
-  if ((i = readlink(CCS filename, s, 1024)) < 0) { s = US"readlink"; goto bad; }
-  filename = s;
-  *(s += i) = '\0';
-  store_release_above(s+1);
+  t = store_get(1024, FALSE);
+  Ustrncpy(t, s, 1022);
+  j = Ustrlen(s);
+  t[j++] = '/';
+  if ((i = readlink(CCS filename, (void *)(t+j), 1023-j)) < 0) { s = US"readlink"; goto bad; }
+  filename = t;
+  *(t += i+j) = '\0';
+  store_release_above(t+1);
   }
 
+#ifdef OpenBSD
+if (kevent(tls_watch_fd, &kev[kev_used-cnt], cnt, &k_dummy, 1, &ts) >= 0)
+  return TRUE;
+#else
 if (kevent(tls_watch_fd, &kev[kev_used-cnt], cnt, NULL, 0, NULL) >= 0)
   return TRUE;
+#endif
 s = US"kevent";
 
 bad:
@@ -282,20 +296,6 @@ struct timespec t = {0};
 (void) kevent(fd, NULL, 0, &kev, 1, &t);
 #endif
 }
-
-/* Called, after a delay for multiple file ops to get done, from
-the daemon when any of the watches added (above) fire.
-
-Dump the set of watches and arrange to reload cached creds (which
-will set up new watches). */
-
-static void
-tls_watch_triggered(void)
-{
-DEBUG(D_tls) debug_printf("watch triggered\n");
-
-tls_daemon_creds_reload();
-}
 #endif /*EXIM_HAVE_INOTIFY*/
 
 
@@ -318,7 +318,7 @@ if (tls_watch_fd < 0) return;
 
 #ifdef EXIM_HAVE_KEVENT
 /* Close the files we had open for kevent */
-for (int fd, i = 0; i < kev_used; i++)
+for (int i = 0; i < kev_used; i++)
   {
   (void) close((int) kev[i].ident);
   kev[i].ident = (uintptr_t)-1;
@@ -334,12 +334,15 @@ tls_watch_fd = -1;
 static void
 tls_daemon_creds_reload(void)
 {
+unsigned lifetime;
+
 #ifdef EXIM_HAVE_KEVENT
 tls_watch_invalidate();
 #endif
 
 tls_server_creds_invalidate();
-tls_server_creds_init();
+tls_creds_expire = (lifetime = tls_server_creds_init())
+  ? time(NULL) + lifetime : 0;
 
 tls_client_creds_reload(TRUE);
 }
@@ -363,10 +366,26 @@ tls_daemon_tick(void)
 {
 tls_per_lib_daemon_tick();
 #if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT)
-if (tls_watch_trigger_time && time(NULL) >= tls_watch_trigger_time + 5)
+if (tls_creds_expire && time(NULL) >= tls_creds_expire)
   {
-  tls_watch_trigger_time = 0;
-  tls_watch_triggered();
+  /* The server cert is a selfsign, with limited lifetime.  Dump it and
+  generate a new one.  Reload the rest of the creds also as the machinery
+  is all there. */
+
+  DEBUG(D_tls) debug_printf("selfsign cert rotate\n");
+  tls_creds_expire = 0;
+  tls_daemon_creds_reload();
+  }
+else if (tls_watch_trigger_time && time(NULL) >= tls_watch_trigger_time + 5)
+  {
+  /* Called, after a delay for multiple file ops to get done, from
+  the daemon when any of the watches added (above) fire.
+  Dump the set of watches and arrange to reload cached creds (which
+  will set up new watches). */
+
+  DEBUG(D_tls) debug_printf("watch triggered\n");
+  tls_watch_trigger_time = tls_creds_expire = 0;
+  tls_daemon_creds_reload();
   }
 #endif
 }
@@ -441,6 +460,9 @@ Returns:       the character
 int
 tls_ungetc(int ch)
 {
+if (ssl_xfer_buffer_lwm <= 0)
+  log_write(0, LOG_MAIN|LOG_PANIC_DIE, "buffer underflow in tls_ungetc");
+
 ssl_xfer_buffer[--ssl_xfer_buffer_lwm] = ch;
 return ch;
 }