[PATCH 3/3] firmware: add support for compressed images

[Trent Piepho]

On Fri, 2016-05-20 at 14:21 +0200, Steffen Trumtrar wrote:
> Allow using compressed firmware images with the firmware framework.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> ---
>  common/firmware.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 78 insertions(+), 4 deletions(-)
> 
> diff --git a/common/firmware.c b/common/firmware.c
> index 664f9107d0f8..6437005bf813 100644
> --- a/common/firmware.c
> +++ b/common/firmware.c
> @@ -22,6 +22,8 @@
>  #include <linux/list.h>
>  #include <linux/stat.h>
>  #include <linux/err.h>
> +#include <uncompress.h>
> +#include <filetype.h>
>  
>  #define BUFSIZ 4096
>  
> @@ -197,16 +199,88 @@ out:
>  }
>  
>  /*
> + * firmware_load_compressed - load a compressed firmware to a device
> + */
> +int firmwaremgr_load_compressed(const char *firmware, const char *dst)
> +{
> +	int srcfd = 0;
> +	int dstfd = 0;
> +	int ret;
> +
> +	srcfd = open(firmware, O_RDONLY);
> +	if (srcfd < 0) {
> +		printf("could not open %s: %s\n", firmware, errno_str());
> +		ret = srcfd;
> +		goto out;
> +	}

Since the firmware was already opened, could the fd be passed to this
function so it doesn't need to be opened again?

> +
> +	dstfd = open(dst, O_WRONLY | O_TRUNC);
> +	if (dstfd < 0) {
> +		printf("could not open %s: %s\n", dst, errno_str());
> +		ret = dstfd;
> +		goto out;
> +	}
> +
> +	ret = uncompress_fd_to_fd(srcfd, dstfd, uncompress_err_stdout);
> +
> +out:
> +	if (dstfd > 0)
> +		close(dstfd);
> +
> +	return ret;
> +}
> +
> +/*
>   * firmware_load_file - load a firmware to a device
>   */
>  int firmwaremgr_load_file(struct firmware_mgr *mgr, const char *firmware)
>  {
> -	int ret;
> -	char *name = basprintf("/dev/%s", mgr->handler->id);
> +	char *dst = basprintf("/dev/%s", mgr->handler->id);
> +	enum filetype type;
> +	int ret = -ENOENT;
> +	int srcfd = 0;
> +	char buf[32];
> +
> +	if (firmware) {
> +		srcfd = open(firmware, O_RDONLY);
> +		if (srcfd < 0) {
> +			printf("could not open %s: %s\n", firmware, errno_str());
> +			ret = srcfd;
> +			goto out;
> +		}
>  
> -	ret = copy_file(firmware, name, 0);
> +		ret = read(srcfd, buf, sizeof(buf));
> +		if (ret < sizeof(buf))
> +			goto out;
>  
> -	free(name);
> +		type = file_detect_type(buf, 32);
> +		if ((int)type < 0) {
> +			printf("could not open %s: %s\n", firmware,
> +					strerror(-type));
> +			ret = (int)type;
> +			goto out;

srcfd is not closed on the error path here.

> +		}
> +
> +		close(srcfd);
> +
> +		switch (type) {
> +		case filetype_lzo_compressed:
> +		case filetype_lz4_compressed:
> +		case filetype_bzip2:
> +		case filetype_gzip:

This is missing xz compression.

Instead of trying to list all compressed types here, and also find the
compressed type of the file, would it make more sense to have the
uncompression code do this?  This way it's not necessary to have a list
that matches what compression algorithms are supported and compiled in.
And uncompress() already reads the file header and determines if the
file type and if it can be uncompressed.  So this code is basically an
incomplete copy of code already in uncompress.c.


> +			ret = firmwaremgr_load_compressed(firmware, dst);
> +			break;
> +		case filetype_unknown:
> +			ret = copy_file(firmware, dst, 0);
> +			break;
> +		default:
> +			ret = -ENOSYS;
> +			printf("unsupported filetype (%d)\n", (int) type);
> +		}
> +	}
> +
> +out:
> +	free(dst);
>  
>  	return ret;
>  }