Change in ...flashrom[master]: [WIP] Add data source/sink abstraction `flashrom_data`

[Nico Huber (Code Review)]

Nico Huber has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/33372

Change subject: [WIP] Add data source/sink abstraction `flashrom_data`
......................................................................

[WIP] Add data source/sink abstraction `flashrom_data`

A first sketch. API will change when I see how it works out.

Change-Id: Ie550914eca2cffb4c14cfdd76289334a2f0636b9
Signed-off-by: Nico Huber 
---
M Makefile
M flash.h
A flashrom_data.c
A flashrom_data_file.c
M libflashrom.h
A libflashrom_file.h
6 files changed, 373 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/72/33372/1

diff --git a/Makefile b/Makefile
index e08a3f6..744344a 100644
--- a/Makefile
+++ b/Makefile
@@ -547,7 +547,10 @@
 ###############################################################################
 # Library code.

-LIB_OBJS = libflashrom.o layout.o flashrom.o udelay.o programmer.o helpers.o ich_descriptors.o fmap.o
+LIB_OBJS = libflashrom.o flashrom_data.o layout.o flashrom.o udelay.o programmer.o helpers.o ich_descriptors.o fmap.o
+ifneq ($(TARGET_OS), libpayload)
+LIB_OBJS += flashrom_data_file.o
+endif

###############################################################################
 # Frontend related stuff.
diff --git a/flash.h b/flash.h
index 911214c..af01479 100644
--- a/flash.h
+++ b/flash.h
@@ -55,6 +55,8 @@

#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))

+#define container_of(ptr, type, member) ((type *)((char *)ptr - offsetof(type, member)))
+
 enum chipbustype {
    BUS_NONE	= 0,
    BUS_PARALLEL	= 1 << 0,
@@ -267,6 +269,10 @@
    bool in_4ba_mode;
 };

+static inline size_t total_size(const struct flashrom_flashctx *flash) {
+	return flash ? flash->chip ? flash->chip->total_size * 1024 : 0 : 0;
+};
+
 /* Timing used in probe routines. ZERO is -2 to differentiate between an unset
  * field and zero delay.
  *
diff --git a/flashrom_data.c b/flashrom_data.c
new file mode 100644
index 0000000..5e541a9
--- /dev/null
+++ b/flashrom_data.c
@@ -0,0 +1,220 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2019 Nico Huber 
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "flash.h"
+#include "libflashrom.h"
+
+/**
+ * @defgroup flashrom-data Data sources/sinks
+ * @{
+ */
+
+struct flash_data {
+	struct flashrom_data data;
+	struct flashrom_flashctx *flash;
+};
+#define FLASH_DATA(d) container_of(d, struct flash_data, data)
+
+static ssize_t flash_readat(
+		void *const buf, const struct flashrom_data *const data,
+		const off_t offset, const size_t count)
+{
+	const struct flash_data *const fdata = FLASH_DATA(data);
+
+	if (!data || !fdata->flash || !fdata->flash->chip || !fdata->flash->chip->read)
+		return -1;
+
+	return fdata->flash->chip->read(fdata->flash, buf, offset, count);
+}
+
+static void flash_release(struct flashrom_data *const data)
+{
+	free(FLASH_DATA(data));
+}
+
+int flashrom_data_from_flash(
+		struct flashrom_data **const data, struct flashrom_flashctx *const flash)
+{
+	struct flash_data *const fdata = malloc(sizeof(*fdata));
+
+	if (!fdata)
+		return -1;
+
+	memset(fdata, 0x00, sizeof(*fdata));
+	fdata->flash = flash;
+	fdata->data.size = total_size(flash);
+	fdata->data.readat = flash_readat;
+	fdata->data.release = flash_release;
+
+	*data = &fdata->data;
+	return 0;
+}
+
+struct buffer_data {
+	struct flashrom_data data;
+	void *buf;
+};
+#define BUFFER_DATA(d) container_of(d, struct buffer_data, data)
+
+static ssize_t buffer_readat(
+		void *const buf, const struct flashrom_data *const data,
+		const off_t offset, const size_t count)
+{
+	const struct buffer_data *const bdata = BUFFER_DATA(data);
+
+	if (!data || !bdata->buf || offset + count > data->size)
+		return -1;
+
+	memcpy(buf, (char *)bdata->buf + offset, count);
+	return count;
+}
+
+static ssize_t buffer_writeat(
+		const struct flashrom_data *const data, const off_t offset,
+		const void *const buf, const size_t count)
+{
+	const struct buffer_data *const bdata = BUFFER_DATA(data);
+
+	if (!data || !bdata->buf || offset + count > data->size)
+		return -1;
+
+	memcpy((char *)bdata->buf + offset, buf, count);
+	return count;
+}
+
+static void buffer_release(struct flashrom_data *const data)
+{
+	free(BUFFER_DATA(data));
+}
+
+int flashrom_data_from_buf(
+		struct flashrom_data **const data, void *const buf, const size_t size)
+{
+	struct buffer_data *const bdata = malloc(sizeof(*bdata));
+
+	if (!bdata)
+		return -1;
+
+	memset(bdata, 0x00, sizeof(*bdata));
+	bdata->buf = buf;
+	bdata->data.size = size;
+	bdata->data.readat = buffer_readat;
+	bdata->data.writeat = buffer_writeat;
+	bdata->data.release = buffer_release;
+
+	*data = &bdata->data;
+	return 0;
+}
+
+struct sub_data {
+	struct flashrom_data data;
+	const struct flashrom_data *parent;
+	off_t offset;
+};
+#define SUB_DATA(d) container_of(d, struct sub_data, data)
+
+static ssize_t sub_readat(
+		void *const buf, const struct flashrom_data *const data,
+		const off_t offset, const size_t count)
+{
+	const struct sub_data *const sdata = SUB_DATA(data);
+
+	if (!data || !sdata->parent || !sdata->parent->readat ||
+	    offset + count > data->size)
+		return -1;
+
+	return sdata->parent->readat(buf, sdata->parent, sdata->offset + offset, count);
+}
+
+static ssize_t sub_writeat(
+		const struct flashrom_data *const data, const off_t offset,
+		const void *const buf, const size_t count)
+{
+	const struct sub_data *const sdata = SUB_DATA(data);
+
+	if (!data || !sdata->parent || !sdata->parent->writeat ||
+	    offset + count > data->size)
+		return -1;
+
+	return sdata->parent->writeat(sdata->parent, sdata->offset + offset, buf, count);
+}
+
+static void sub_release(struct flashrom_data *const data)
+{
+	free(SUB_DATA(data));
+}
+
+int flashrom_data_subregion(
+		struct flashrom_data **const data,
+		const struct flashrom_data *const parent,
+		const off_t offset, const size_t size)
+{
+	if (!parent || offset + size > parent.size)
+		return -1;
+
+	struct sub_data *const sdata = malloc(sizeof(*sdata));
+
+	if (!sdata)
+		return -1;
+
+	memset(sdata, 0x00, sizeof(*sdata));
+	sdata->parent = parent;
+	sdata->offset = offset;
+	sdata->data.size = size;
+	sdata->data.readat = parent->readat ? sub_readat : NULL;
+	sdata->data.writeat = parent->writeat ? sub_writeat : NULL;
+	sdata->data.release = sub_release;
+
+	*data = &sdata->data;
+	return 0;
+}
+
+ssize_t flashrom_data_copy(
+		const struct flashrom_data *const dst,
+		const struct flashrom_data *const src)
+{
+	ssize_t ret = -1;
+
+	if (!dst || !dst->writeat || !src || !src->readat)
+		return ret;
+	if (dst->size != src->size)
+		return ret;
+
+	void *const buf = malloc(dst->size);
+	if (!buf)
+		return ret;
+
+	if (src->readat(buf, src, 0, dst->size) != dst->size)
+		goto _free_ret;
+
+	ret = dst->writeat(dst, 0, buf, dst->size);
+
+_free_ret:
+	free(buf);
+	return ret;
+}
+
+void flashrom_data_release(struct flashrom_data *const data)
+{
+	if (data->release)
+		data->release(data);
+}
+
+/** @} */ /* end flashrom-data */
diff --git a/flashrom_data_file.c b/flashrom_data_file.c
new file mode 100644
index 0000000..d7e1c66
--- /dev/null
+++ b/flashrom_data_file.c
@@ -0,0 +1,95 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2019 Nico Huber 
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "flash.h"
+#include "libflashrom.h"
+#include "libflashrom_file.h"
+
+/** @ingroup flashrom-data */
+
+struct file_data {
+	struct flashrom_data data;
+	FILE *file;
+};
+#define FILE_DATA(d) container_of(d, struct file_data, data)
+
+static ssize_t file_readat(
+		void *const buf, const struct flashrom_data *const data,
+		const off_t offset, const size_t count)
+{
+	const struct file_data *const fdata = FILE_DATA(data);
+
+	if (!data || !fdata->file)
+		return -1;
+
+	if (fseek(fdata->file, offset, SEEK_SET) != 0)
+		return -1;
+	if (fread(buf, count, 1, fdata->file) != 1)
+		return -1;
+
+	return count;
+}
+
+static ssize_t file_writeat(
+		const struct flashrom_data *const data, const off_t offset,
+		const void *const buf, const size_t count)
+{
+	const struct file_data *const fdata = FILE_DATA(data);
+
+	if (!data || !fdata->file)
+		return -1;
+
+	if (fseek(fdata->file, offset, SEEK_SET) != 0)
+		return -1;
+	if (fwrite(buf, count, 1, fdata->file) != 1)
+		return -1;
+
+	return count;
+}
+
+static void file_release(struct flashrom_data *const data)
+{
+	free(FILE_DATA(data));
+}
+
+int flashrom_data_from_file(struct flashrom_data **const data, FILE *const file)
+{
+	struct file_data *const fdata = malloc(sizeof(*fdata));
+
+	if (!fdata || !file)
+		return -1;
+
+	if (fseek(file, 0, SEEK_END) != 0)
+		return -1;
+
+	const long pos = ftell(file);
+	if (pos < 0 || pos > SIZE_MAX)
+		return -1;
+
+	memset(fdata, 0x00, sizeof(*fdata));
+	fdata->file = file;
+	fdata->data.size = (size_t)pos;
+	fdata->data.readat = file_readat;
+	fdata->data.writeat = file_writeat;
+	fdata->data.release = file_release;
+
+	*data = &fdata->data;
+	return 0;
+}
diff --git a/libflashrom.h b/libflashrom.h
index 38c95d2..01ecd3f 100644
--- a/libflashrom.h
+++ b/libflashrom.h
@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2012 secunet Security Networks AG
  * (Written by Nico Huber  for secunet)
+ * Copyright (C) 2019 Nico Huber 
  *
  * 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
@@ -47,6 +48,26 @@
 int flashrom_flash_erase(struct flashrom_flashctx *);
 void flashrom_flash_release(struct flashrom_flashctx *);

+/** @ingroup flashrom-data */
+/** Representation of a data source/sink (can be flash, a file, memory buffer, ...) */
+struct flashrom_data {
+	size_t size;
+
+	/* Offsets are relative to the `flashrom_data` instance, not the `buf`. */
+	ssize_t (*readat)(void *buf, const struct flashrom_data *, off_t offset, size_t count);
+	ssize_t (*writeat)(const struct flashrom_data *, off_t offset, const void *buf, size_t count);
+
+	void (*release)(struct flashrom_data *);
+};
+
+int flashrom_data_from_flash(struct flashrom_data **, struct flashrom_flashctx *);
+int flashrom_data_from_buf(struct flashrom_data **, void *, size_t);
+int flashrom_data_subregion(struct flashrom_data **, const struct flashrom_data *parent, off_t, size_t);
+
+ssize_t flashrom_data_copy(const struct flashrom_data *dst, const struct flashrom_data *src);
+
+void flashrom_data_release(struct flashrom_data *);
+
 /** @ingroup flashrom-flash */
 enum flashrom_flag {
    FLASHROM_FLAG_FORCE,
diff --git a/libflashrom_file.h b/libflashrom_file.h
new file mode 100644
index 0000000..54de515
--- /dev/null
+++ b/libflashrom_file.h
@@ -0,0 +1,27 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2019 Nico Huber 
+ *
+ * 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.
+ */
+
+#ifndef __LIBFLASHROM_FILE_H__
+#define __LIBFLASHROM_FILE_H__ 1
+
+#include <stdio.h>
+
+#include "libflashrom.h"
+
+/** @ingroup flashrom-data */
+int flashrom_data_from_file(struct flashrom_data **, FILE *);
+
+#endif				/* !__LIBFLASHROM_FILE_H__ */