helper: added slbt_map_input(), slbt_unmap_input().

1 files changed, 67 insertions, 0 deletions

diff --git a/src/helper/slbt_map_input.c b/src/helper/slbt_map_input.c
new file mode 100644
index 0000000..5cd7774
--- /dev/null
+++ b/src/helper/slbt_map_input.c
@@ -0,0 +1,67 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2015--2023  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_errinfo_impl.h"
+
+int slbt_map_input(
+	const struct slbt_driver_ctx *	dctx,
+	int				fd,
+	const char *			path,
+	int				prot,
+	struct slbt_input *		map)
+{
+	int		ret;
+	struct stat	st;
+	bool		fnew;
+	int		fdcwd;
+
+	fdcwd = slbt_driver_fdcwd(dctx);
+
+	if ((fnew = (fd < 0)))
+		fd  = openat(fdcwd,path,O_RDONLY | O_CLOEXEC);
+
+	if (fd < 0)
+		return SLBT_SYSTEM_ERROR(dctx,path);
+
+	if ((ret = fstat(fd,&st) < 0) && fnew)
+		close(fd);
+
+	else if ((st.st_size == 0) && fnew)
+		close(fd);
+
+	if (ret < 0)
+		return SLBT_SYSTEM_ERROR(dctx,path);
+
+	if (st.st_size == 0) {
+		map->size = 0;
+		map->addr = 0;
+	} else {
+		map->size = st.st_size;
+		map->addr = mmap(0,map->size,prot,MAP_PRIVATE,fd,0);
+	}
+
+	if (fnew)
+		close(fd);
+
+	return (map->addr == MAP_FAILED)
+		? SLBT_SYSTEM_ERROR(dctx,path)
+		: 0;
+}
+
+int slbt_unmap_input(struct slbt_input * map)
+{
+	return map->size ? munmap(map->addr,map->size) : 0;
+}