/* $NetBSD: firmload.c,v 1.1 2017/08/10 20:43:12 jmcneill Exp $ */

/*-
* Copyright (c) 2017 Jared McNeill <[email protected]>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/param.h>
#include <sys/sysctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "firmload.h"

#define HW_FIRMWARE_PATH        "hw.firmware.path"
#define HW_FIRMWARE_PATH_DELIM  ":"

static int
firmware_search(char *paths, const char *drvname, const char *imgname)
{
       char *p, *f;
       const int debug = getenv("FIRMWARE_DEBUG") != NULL;
       int fd;

       p = strtok(paths, HW_FIRMWARE_PATH_DELIM);
       while (p) {
               if (asprintf(&f, "%s/%s/%s", p, drvname, imgname) == -1)
                       return -1;
               if (debug)
                       printf("%s: trying %s...\n", __func__, f);
               fd = open(f, O_RDONLY);
               free(f);
               if (fd != -1) {
                       if (debug)
                               printf("%s: using image at %s\n", __func__, f);
                       return fd;
               }
               p = strtok(NULL, HW_FIRMWARE_PATH_DELIM);
       }

       /* Not found */
       return -1;
}

int
firmware_open(const char *drvname, const char *imgname)
{
       size_t len;
       char *paths;
       int fd;

       paths = asysctlbyname(HW_FIRMWARE_PATH, &len);
       if (paths == NULL)
               return -1;

       fd = firmware_search(paths, drvname, imgname);

       free(paths);

       return fd;
}