flashrom.c: Move read_buf_from_file() to helpers_fileio.c

Constructing a buffer from a read file is auxiliary
functionality to the core flashrom algorithms. Move
aside to decrease the overall complexity of flashrom.c

BUG=b:242246291
TEST=builds

Change-Id: Ia6e1eeb876722899defb5b75346d1f22c70bfbd1
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/66645
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Evan Benn <evanbenn@google.com>
Reviewed-by: Sam McNally <sammc@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Thomas Heijligen <src@posteo.de>

1 files changed, 71 insertions, 0 deletions

diff --git a/helpers_fileio.c b/helpers_fileio.c
new file mode 100644
index 00000000..550d98d2
--- /dev/null
+++ b/helpers_fileio.c
@@ -0,0 +1,71 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2009-2010 Carl-Daniel Hailfinger
+ * Copyright (C) 2013 Stefan Tauner
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#ifndef __LIBPAYLOAD__
+#include <sys/stat.h>
+#endif
+
+#include "flash.h"
+
+int read_buf_from_file(unsigned char *buf, unsigned long size,
+		       const char *filename)
+{
+#ifdef __LIBPAYLOAD__
+	msg_gerr("Error: No file I/O support in libpayload\n");
+	return 1;
+#else
+	int ret = 0;
+
+	FILE *image;
+	if (!strcmp(filename, "-"))
+		image = fdopen(fileno(stdin), "rb");
+	else
+		image = fopen(filename, "rb");
+	if (image == NULL) {
+		msg_gerr("Error: opening file \"%s\" failed: %s\n", filename, strerror(errno));
+		return 1;
+	}
+
+	struct stat image_stat;
+	if (fstat(fileno(image), &image_stat) != 0) {
+		msg_gerr("Error: getting metadata of file \"%s\" failed: %s\n", filename, strerror(errno));
+		ret = 1;
+		goto out;
+	}
+	if ((image_stat.st_size != (intmax_t)size) && strcmp(filename, "-")) {
+		msg_gerr("Error: Image size (%jd B) doesn't match the expected size (%lu B)!\n",
+			 (intmax_t)image_stat.st_size, size);
+		ret = 1;
+		goto out;
+	}
+
+	unsigned long numbytes = fread(buf, 1, size, image);
+	if (numbytes != size) {
+		msg_gerr("Error: Failed to read complete file. Got %ld bytes, "
+			 "wanted %ld!\n", numbytes, size);
+		ret = 1;
+	}
+out:
+	(void)fclose(image);
+	return ret;
+#endif
+}