Move liblttng-ust-fd to 'src/lib/'

[lttng-ust.git] / src / lib / lttng-ust-fd / lttng-ust-fd.c

diff --git a/src/lib/lttng-ust-fd/lttng-ust-fd.c b/src/lib/lttng-ust-fd/lttng-ust-fd.c
new file mode 100644 (file)
index 0000000..5efc0ac
--- /dev/null
+++ b/src/lib/lttng-ust-fd/lttng-ust-fd.c
@@ -0,0 +1,76 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2016  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#define _LGPL_SOURCE
+#include <limits.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "common/ust-fd.h"
+#include <dlfcn.h>
+
+#include "common/macros.h"
+
+static int (*__lttng_ust_fd_plibc_close)(int fd);
+static int (*__lttng_ust_fd_plibc_fclose)(FILE *stream);
+
+static
+int _lttng_ust_fd_libc_close(int fd)
+{
+       if (!__lttng_ust_fd_plibc_close) {
+               __lttng_ust_fd_plibc_close = dlsym(RTLD_NEXT, "close");
+               if (!__lttng_ust_fd_plibc_close) {
+                       fprintf(stderr, "%s\n", dlerror());
+                       return -1;
+               }
+       }
+       return lttng_ust_safe_close_fd(fd, __lttng_ust_fd_plibc_close);
+}
+
+static
+int _lttng_ust_fd_libc_fclose(FILE *stream)
+{
+       if (!__lttng_ust_fd_plibc_fclose) {
+               __lttng_ust_fd_plibc_fclose = dlsym(RTLD_NEXT, "fclose");
+               if (!__lttng_ust_fd_plibc_fclose) {
+                       fprintf(stderr, "%s\n", dlerror());
+                       return -1;
+               }
+       }
+       return lttng_ust_safe_fclose_stream(stream,
+                       __lttng_ust_fd_plibc_fclose);
+}
+
+int close(int fd)
+{
+       return _lttng_ust_fd_libc_close(fd);
+}
+
+/*
+ * Note: fcloseall() is not an issue because it fcloses only the
+ * streams it knows about, which differs from the problems caused by
+ * gnulib close_stdout(), which does an explicit fclose(stdout).
+ */
+int fclose(FILE *stream)
+{
+       return _lttng_ust_fd_libc_fclose(stream);
+}
+
+#if defined(__sun__) || defined(__FreeBSD__)
+/* Solaris and FreeBSD. */
+void closefrom(int lowfd)
+{
+       (void) lttng_ust_safe_closefrom_fd(lowfd, __lttng_ust_fd_plibc_close);
+}
+#elif defined(__NetBSD__) || defined(__OpenBSD__)
+/* NetBSD and OpenBSD. */
+int closefrom(int lowfd)
+{
+       return lttng_ust_safe_closefrom_fd(lowfd, __lttng_ust_fd_plibc_close);
+}
+#else
+/* As far as we know, this OS does not implement closefrom. */
+#endif