From 0f9f9744d71f902054aa844bd2f136d8307a13dc Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Wed, 27 Jun 2018 20:12:56 -0400
Subject: internals: added slbt_map_file(), slbt_unmap_file().

---
 src/internal/slibtool_mapfile_impl.c | 78 ++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src/internal/slibtool_mapfile_impl.c

(limited to 'src/internal/slibtool_mapfile_impl.c')

diff --git a/src/internal/slibtool_mapfile_impl.c b/src/internal/slibtool_mapfile_impl.c
new file mode 100644
index 0000000..e5d40d1
--- /dev/null
+++ b/src/internal/slibtool_mapfile_impl.c
@@ -0,0 +1,78 @@
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include "slibtool_mapfile_impl.h"
+
+static void slbt_munmap(void * addr, size_t size)
+{
+	if (addr) {
+		munmap(addr,size);
+	}
+}
+
+struct slbt_map_info * slbt_map_file(
+	int		fdat,
+	const char *	path,
+	uint32_t	flags)
+{
+	int 			fd;
+	void *			addr;
+	struct stat		st;
+	uint32_t		oflag;
+	uint32_t		mprot;
+	struct slbt_map_info *	mapinfo;
+
+	if ((flags & SLBT_MAP_INPUT) && (flags & SLBT_MAP_OUTPUT))  {
+		oflag = O_RDWR;
+		mprot = PROT_READ|PROT_WRITE;
+	} else if (flags & SLBT_MAP_INPUT) {
+		oflag = O_RDONLY;
+		mprot = PROT_READ;
+	} else if (flags & SLBT_MAP_OUTPUT) {
+		oflag = O_WRONLY;
+		mprot = PROT_WRITE;
+	} else {
+		errno = EINVAL;
+		return 0;
+	}
+
+	if ((fd = openat(fdat,path,oflag,0)) < 0)
+		return 0;
+
+	if (fstat(fd,&st) < 0) {
+		close(fd);
+		return 0;
+	}
+
+	addr = st.st_size
+		? mmap(0,st.st_size,mprot,MAP_SHARED,fd,0)
+		: 0;
+
+	if (addr == MAP_FAILED) {
+		close(fd);
+		return 0;
+	}
+
+	if (!(mapinfo = malloc(sizeof(*mapinfo)))) {
+		close(fd);
+		slbt_munmap(addr,st.st_size);
+		return 0;
+	}
+
+	close(fd);
+
+	mapinfo->addr = addr;
+	mapinfo->size = st.st_size;
+
+	return mapinfo;
+}
+
+void slbt_unmap_file(struct slbt_map_info * mapinfo)
+{
+	slbt_munmap(mapinfo->addr,mapinfo->size);
+	free(mapinfo);
+}
-- 
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