/* gpu-manager:
 *
 * Detect the available GPUs and deal with any system changes, whether
 * software or hardware related
 *
 * Authored by:
 *   Alberto Milone
 *
 *
 * Copyright (C) 2014 Canonical Ltd
 *
 * Based on code from ./hw/xfree86/common/xf86pciBus.c in xorg-server
 * Also based on hybrid-detect.c in ubuntu-drivers-common.
 *
 * Copyright (c) 1997-2003 by The XFree86 Project, Inc.
 *
 * PCI code based on example.c from pciutils, by Martin Mares.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name of the copyright holder(s)
 * and author(s) shall not be used in advertising or otherwise to promote
 * the sale, use or other dealings in this Software without prior written
 * authorization from the copyright holder(s) and author(s).
 *
 *
 * Build with `gcc -o gpu-manager gpu-manager.c $(pkg-config --cflags --libs pciaccess libdrm)`
 */

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <ctype.h>
#include <pci/pci.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <getopt.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#include <linux/limits.h>
#include <sys/utsname.h>
#include <libkmod.h>
#include "xf86drm.h"
#include "xf86drmMode.h"
#include "json.h"

static inline void freep(void *);
static inline void fclosep(FILE **);
static inline void pclosep(FILE **);

#define _cleanup_free_ __attribute__((cleanup(freep)))
#define _cleanup_fclose_ __attribute__((cleanup(fclosep)))
#define _cleanup_pclose_ __attribute__((cleanup(pclosep)))

#define PCI_CLASS_DISPLAY               0x03
#define PCI_CLASS_DISPLAY_OTHER         0x0380

#define PCIINFOCLASSES(c) \
    ( (( ((c) >> 8) & 0xFF) \
     == PCI_CLASS_DISPLAY) )

#define LAST_BOOT "/var/lib/ubuntu-drivers-common/last_gfx_boot"
#define OFFLOADING_CONF "/var/lib/ubuntu-drivers-common/requires_offloading"
#define RUNTIMEPM_OVERRIDE "/etc/u-d-c-nvidia-runtimepm-override"
#define UDEV_NVIDIA_COMPLETED "/run/u-d-c-nvidia-drm-was-loaded"
#define XORG_CONF "/etc/X11/xorg.conf"
#define KERN_PARAM "nogpumanager"
#define AMDGPU_PRO_PX  "/opt/amdgpu-pro/bin/amdgpu-pro-px"
#define CHASSIS_PATH "/sys/devices/virtual/dmi/id/chassis_type"

#define AMD 0x1002
#define INTEL 0x8086
#define NVIDIA 0x10de

#define MAX_CARDS_N 10

typedef enum {
    SNA,
    MODESETTING,
    UXA
} prime_intel_drv;

typedef enum {
    MODE_POWERSAVING,
    MODE_PERFORMANCE,
    RESET,
    ISPX,
} amdgpu_pro_px_action;

typedef enum {
    ON,
    OFF,
    ONDEMAND
} prime_mode_settings;

static char *log_file = NULL;
static FILE *log_handle = NULL;
static char *last_boot_file = NULL;
static int dry_run = 0;
static char *fake_modules_path = NULL;
static char *gpu_detection_path = NULL;
static char *prime_settings = NULL;
static char *dmi_product_name_path = NULL;
static char *dmi_product_version_path = NULL;
static char *nvidia_driver_version_path = NULL;
static char *amdgpu_pro_px_file = NULL;
static char *modprobe_d_path = NULL;
static char *xorg_conf_d_path = NULL;
static prime_intel_drv prime_intel_driver = SNA;
static prime_mode_settings prime_mode = OFF;
static bool nvidia_runtimepm_supported = false;
static bool nvidia_runtimepm_enabled = false;

struct device {
    int boot_vga;
    unsigned int vendor_id;
    unsigned int device_id;
    /* BusID components */
    unsigned int domain;
    unsigned int bus;
    unsigned int dev;
    unsigned int func;
    int has_connected_outputs;
};


/* Struct we use to check PME */
struct pme_dev {
    struct pme_dev *next;
    struct pci_dev *dev;
    /* Cache */
    unsigned int config_cached, config_bufsize;
    u8 *config;    /* Cached configuration space data */
    u8 *present;   /* Maps which configuration bytes are present */
};


static bool is_file(char *file);
static bool is_dir(char *directory);
static bool is_dir_empty(char *directory);
static bool is_link(char *file);
static bool is_module_loaded(const char *module);
static bool get_nvidia_driver_version(int *major, int *minor, int *extra);

static inline void freep(void *p) {
    free(*(void**) p);
}


static inline void fclosep(FILE **file) {
    if (*file != NULL && *file >= 0)
        fclose(*file);
}


static inline void pclosep(FILE **file) {
    if (*file != NULL)
        pclose(*file);
}

/* Beginning of the parts from lspci.{c|h} */
static int
pme_config_fetch(struct pme_dev *pm_dev, unsigned int pos, unsigned int len)
{
    unsigned int end = pos+len;
    int result;

    while (pos < pm_dev->config_bufsize && len && pm_dev->present[pos])
        pos++, len--;
    while (pos+len <= pm_dev->config_bufsize && len && pm_dev->present[pos+len-1])
        len--;
    if (!len)
        return 1;

    if (end > pm_dev->config_bufsize) {
        int orig_size = pm_dev->config_bufsize;
        while (end > pm_dev->config_bufsize)
        pm_dev->config_bufsize *= 2;
        pm_dev->config = realloc(pm_dev->config, pm_dev->config_bufsize);
        if (! pm_dev->config) {
            fprintf(log_handle, "Error: failed to reallocate pm_dev config\n");
            return 0;
        }
        pm_dev->present = realloc(pm_dev->present, pm_dev->config_bufsize);
        if (! pm_dev->present) {
            fprintf(log_handle, "Error: failed to reallocate pm_dev present\n");
            return 0;
        }
        memset(pm_dev->present + orig_size, 0, pm_dev->config_bufsize - orig_size);
    }
    result = pci_read_block(pm_dev->dev, pos, pm_dev->config + pos, len);
    if (result)
        memset(pm_dev->present + pos, 1, len);
  return result;
}


/* Config space accesses */
static void
check_conf_range(struct pme_dev *pm_dev, unsigned int pos, unsigned int len)
{
    while (len)
        if (!pm_dev->present[pos]) {
            fprintf(log_handle,
                    "Internal bug: Accessing non-read configuration byte at position %x\n",
                    pos);
        }
        else {
            pos++, len--;
        }
}


static u8
get_conf_byte(struct pme_dev *pm_dev, unsigned int pos)
{
    check_conf_range(pm_dev, pos, 1);
    return pm_dev->config[pos];
}


static u16
get_conf_word(struct pme_dev *pm_dev, unsigned int pos)
{
    check_conf_range(pm_dev, pos, 2);
    return pm_dev->config[pos] | (pm_dev->config[pos+1] << 8);
}


static bool get_d3_substates(struct pme_dev *d, bool *d3cold, bool *d3hot) {
    bool status = false;
    int where = PCI_CAPABILITY_LIST;

    if (get_conf_word(d, PCI_STATUS) & PCI_STATUS_CAP_LIST) {
        u8 been_there[256];
        where = get_conf_byte(d, where) & ~3;
        memset(been_there, 0, 256);
        while (where) {
            int id, cap;
            /* Look for the capabilities */
            if (!pme_config_fetch(d, where, 4)) {
                fprintf(log_handle, "Warning: access to PME Capabilities was denied\n");
                break;
            }
            id = get_conf_byte(d, where + PCI_CAP_LIST_ID);
            cap = get_conf_word(d, where + PCI_CAP_FLAGS);
            if (been_there[where]++) {
                /* chain looped */
                break;
            }
            if (id == 0xff) {
                /* chain broken */
                break;
            }
            switch (id) {
            case PCI_CAP_ID_NULL:
                break;
            case PCI_CAP_ID_PM:
                *d3hot = (cap & PCI_PM_CAP_PME_D3_HOT);
                *d3cold = (cap & PCI_PM_CAP_PME_D3_COLD);
                status = true;
                break;
            }
        }
    }
    return status;
}


static struct pme_dev *
scan_device(struct pci_dev *p) {
    struct pme_dev *pm_dev = NULL;

    pm_dev = malloc(sizeof(struct pme_dev));
    if (!pm_dev) {
        fprintf(log_handle, "Error: failed to allocate pme_dev\n");
        return NULL;
    }
    memset(pm_dev, 0, sizeof(*pm_dev));
    pm_dev->dev = p;
    pm_dev->config_cached = pm_dev->config_bufsize = 64;
    pm_dev->config = malloc(64);
    if (!pm_dev->config) {
        fprintf(log_handle, "Error: failed to allocate pme_dev config\n");
        return NULL;
    }
    pm_dev->present = malloc(64);
    if (!pm_dev->present) {
        fprintf(log_handle, "Error: failed to allocate pme_dev present\n");
        return NULL;
    }
    memset(pm_dev->present, 1, 64);
    if (!pci_read_block(p, 0, pm_dev->config, 64)) {
        fprintf(log_handle, "lspci: Unable to read the standard configuration space header of pm_dev %04x:%02x:%02x.%d\n",
                p->domain, p->bus, p->dev, p->func);
        return NULL;
    }
    if ((pm_dev->config[PCI_HEADER_TYPE] & 0x7f) == PCI_HEADER_TYPE_CARDBUS) {
      /* For cardbus bridges, we need to fetch 64 bytes more to get the
       * full standard header... */
        if (pme_config_fetch(pm_dev, 64, 64))
            pm_dev->config_cached += 64;
    }
    pci_setup_cache(p, pm_dev->config, pm_dev->config_cached);
    /* We don't need this again */
    //pci_fill_info(p, PCI_FILL_IDENT | PCI_FILL_CLASS);
    return pm_dev;
}
/* End parts from lspci.{c|h} */


static bool pci_device_is_boot_vga(struct pci_dev *info) {
    size_t len = 0;
    _cleanup_free_ char *boot_vga_str = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    char sysfs_path[1024];

    snprintf(sysfs_path, sizeof(sysfs_path),
             "/sys/bus/pci/devices/%04x:%02x:%02x.%d/boot_vga",
             info->domain, info->bus, info->dev, info->func);

    /* Check the driver version */
    file = fopen(sysfs_path, "r");
    if (file == NULL) {
        fprintf(log_handle, "can't open %s\n", sysfs_path);
        return false;
    }
    if (getline(&boot_vga_str, &len, file) == -1) {
        fprintf(log_handle, "can't get line from %s\n", sysfs_path);
        return false;
    }
    return (strcmp(boot_vga_str, "1\n") == 0);
}


/* Trim string in place */
static void trim(char *str) {
    char *pointer = str;
    int len = strlen(pointer);

    while(isspace(pointer[len - 1]))
        pointer[--len] = 0;

    while(* pointer && isspace(* pointer)) {
        ++pointer;
        --len;
    }

    memmove(str, pointer, len + 1);
}


static char* get_system_architecture() {
    struct utsname buffer;
    char * arch = NULL;

    errno = 0;
    if (uname(&buffer) != 0) {
        return NULL;
    }
    /* We can get away with this since we
     * only build gpu-manager on x86
     */
    asprintf(&arch, "%s-linux-gnu",
             buffer.machine);

    return arch;
}


static bool starts_with(const char *string, const char *prefix) {
    size_t prefix_len = strlen(prefix);
    size_t string_len = strlen(string);
    return string_len < prefix_len ? 0 : strncmp(prefix, string, prefix_len) == 0;
}


/* Case insensitive equivalent of strstr */
static const char *istrstr(const char *str1, const char *str2) {
    if (!*str2)
    {
      return str1;
    }
    for (; *str1; ++str1) {
        /* Look for the 1st character */
        if (toupper(*str1) == toupper(*str2)) {
            /* We have a match. Let's loop through the
             * remaining characters.
             * chr1 belongs to str1, whereas chr2 belongs to str2.
             */
            const char *chr1, *chr2;
            for (chr1 = str1, chr2 = str2; *chr1 && *chr2; ++chr1, ++chr2) {
                if (toupper(*chr1) != toupper(*chr2)) {
                    break;
                }
            }
            /* If we have matched all of str2 and we have arrived
             * at NULL termination, then we're done.
             * Let's return str1.
             */
            if (!*chr2) {
                return str1;
            }
        }
    }
    return NULL;
}


static bool exists_not_empty(const char *file) {
    struct stat stbuf;

    /* If file doesn't exist */
    if (stat(file, &stbuf) == -1) {
        fprintf(log_handle, "can't access %s\n", file);
        return false;
    }
    /* If file is empty */
    if ((stbuf.st_mode & S_IFMT) && ! stbuf.st_size) {
        fprintf(log_handle, "%s is empty\n", file);
        return false;
    }
    return true;
}

#if 0
/* Get reference count from module */
static int get_module_refcount(const char* module) {
    _cleanup_fclose_ FILE *file = NULL;
    _cleanup_free_ char *line = NULL;
    size_t len = 0;
    char refcount_path[50];
    int refcount = 0;
    int status = 0;

    snprintf(refcount_path, sizeof(refcount_path), "/sys/module/%s/refcnt", module);

    if (!exists_not_empty(refcount_path)) {
        fprintf(log_handle, "Error: %s does not exist or is empty.\n", refcount_path);
        return 0;
    }

    /* get dmi product version */
    file = fopen(refcount_path, "r");
    if (file == NULL) {
        fprintf(log_handle, "can't open %s\n", refcount_path);
        return 0;
    }
    if (getline(&line, &len, file) == -1) {
        fprintf(log_handle, "can't get line from %s\n", refcount_path);
        return 0;
    }

    status = sscanf(line, "%d\n", &refcount);

    /* Make sure that we match 1 time */
    if (status == EOF || status != 1)
        refcount = 0;

    return refcount;
}
#endif


static bool act_upon_module_with_params(const char *module,
                                       int mode,
                                       char *params) {
    int status = 0;
    char command[300];

    fprintf(log_handle, "%s %s with \"%s\" parameters\n",
            mode ? "Loading" : "Unloading",
            module, params ? params : "no");

    if (params) {
        snprintf(command, sizeof(command), "%s %s %s",
                 mode ? "/sbin/modprobe" : "/sbin/rmmod",
                 module, params);
        free(params);
    }
    else {
        snprintf(command, sizeof(command), "%s %s",
                 mode ? "/sbin/modprobe" : "/sbin/rmmod",
                 module);
    }

    if (dry_run)
        return true;

    status = system(command);

    return (status == 0);
}

/* Load a kernel module and pass it parameters */
static bool load_module_with_params(const char *module,
                                   char *params) {
    return (act_upon_module_with_params(module, 1, params));
}


/* Load a kernel module */
static bool load_module(const char *module) {
    return (load_module_with_params(module, NULL));
}


/* Unload a kernel module */
static bool unload_module(const char *module) {
    return (act_upon_module_with_params(module, 0, NULL));
}


/* Get the first match from the output of a command */
static char* get_output(const char *command, const char *pattern, const char *ignore) {
    int len;
    char buffer[1035];
    char *output = NULL;
    _cleanup_pclose_ FILE *pfile = NULL;
    pfile = popen(command, "r");
    if (pfile == NULL) {
        fprintf(stderr, "Failed to run command %s\n", command);
        return NULL;
    }

    while (fgets(buffer, sizeof(buffer), pfile)) {
        /* If no search pattern was provided, just
         * return the first non zero legth line
         */
        if (!pattern) {
            output = strdup(buffer);
            break;
        }
        else {
            /* Look for the search pattern */
            if (ignore && (strstr(buffer, ignore) != NULL)) {
                /* Skip this line */
                continue;
            }
            /* Look for the pattern */
            if (strstr(buffer, pattern) != NULL) {
                output = strdup(buffer);
                break;
            }
        }
    }

    if (output) {
        /* Remove newline */
        len = strlen(output);
        if(output[len-1] == '\n' )
           output[len-1] = 0;
    }
    return output;
}


static bool is_module_blacklisted(const char* module) {
    _cleanup_free_ char *match = NULL;
    char command[100];

    /* It will be a file if it's a test */
    if (dry_run) {
        snprintf(command, sizeof(command),
                 "grep -G \"blacklist.*%s[[:space:]]*$\" %s",
                 module, modprobe_d_path);

        if (exists_not_empty(modprobe_d_path))
            match = get_output(command, NULL, NULL);
    }
    else {
        snprintf(command, sizeof(command),
                 "grep -G \"^blacklist.*%s[[:space:]]*$\" %s/*.conf",
                 module, modprobe_d_path);

        match = get_output(command, NULL, NULL);

        if (!match) {
            snprintf(command, sizeof(command),
                 "grep -G \"^blacklist.*%s[[:space:]]*$\" %s/*.conf",
                 module, "/lib/modprobe.d");

            match = get_output(command, NULL, NULL);
        }
    }

    if (!match)
        return false;
    return true;
}


/* Look for unloaded modules */
static bool has_unloaded_module(char *module) {
    char path[PATH_MAX];

    snprintf(path, sizeof(path), "%s/u-d-c-%s-was-loaded",
             gpu_detection_path, module);

    if (is_file(path) && !is_module_loaded(module)) {
        fprintf(log_handle, "%s was unloaded\n", module);
        return true;
    }

    return false;
}


static bool find_string_in_file(const char *path, const char *pattern) {
    _cleanup_free_ char *line = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    size_t len = 0;
    size_t read;

    bool found = false;

    file = fopen(path, "r");
    if (file == NULL)
         return found;
    while ((read = getline(&line, &len, file)) != -1) {
        if (istrstr(line, pattern) != NULL) {
            found = true;
            break;
        }
    }

    return found;
}


static bool is_file_empty(const char *file) {
    struct stat stbuf;

    if (stat(file, &stbuf) == -1) {
        fprintf(log_handle, "can't access %s\n", file);
        return false;
    }
    if ((stbuf.st_mode & S_IFMT) && ! stbuf.st_size)
        return true;

    return false;
}


static bool has_cmdline_option(const char *option)
{
    return (find_string_in_file("/proc/cmdline", option));
}


static bool is_disabled_in_cmdline() {
    return has_cmdline_option(KERN_PARAM);
}


static prime_intel_drv get_prime_intel_driver() {
    prime_intel_drv driver;
    if (has_cmdline_option("gpumanager_modesetting")) {
        driver = MODESETTING;
        fprintf(log_handle, "Detected boot parameter to force the modesetting driver\n");
    }
    else if (has_cmdline_option("gpumanager_uxa")) {
        driver = UXA;
        fprintf(log_handle, "Detected boot parameter to force Intel/UXA\n");
    }
    else if (has_cmdline_option("gpumanager_sna")) {
        driver = SNA;
        fprintf(log_handle, "Detected boot parameter to force Intel/SNA\n");
    }
    else {
        driver = MODESETTING;
    }

    return driver;
}


static bool copy_file(const char *src_path, const char *dst_path)
{
    _cleanup_fclose_ FILE *src = NULL;
    _cleanup_fclose_ FILE *dst = NULL;
    int src_fd, dst_fd;
    int n = 0;
    char buf[BUFSIZ];

    src = fopen(src_path, "r");
    if (src == NULL) {
        fprintf(log_handle, "error: can't open %s for reading\n", src_path);
        return false;
    }

    dst = fopen(dst_path, "w");
    if (dst == NULL) {
        fprintf(log_handle, "error: can't open %s for writing.\n",
                dst_path);
        return false;
    }

    src_fd = fileno(src);
    dst_fd = fileno(dst);

    fprintf(log_handle, "copying %s to %s...\n", src_path, dst_path);

    while ((n = read(src_fd, buf, BUFSIZ)) > 0)
        if (write(dst_fd, buf, n) != n) {
            fprintf(log_handle, "write error on file %s\n", dst_path);
            return false;
        }

    fprintf(log_handle, "%s was copied successfully to %s\n", src_path, dst_path);
    return true;
}


/* Get prime action, which can be "on", "off", or "on-demand" */
static void get_prime_action() {
    char line[100];
    _cleanup_fclose_ FILE *file = NULL;

    file = fopen(prime_settings, "r");

    if (!file) {
        fprintf(log_handle, "Error: can't open %s\n", prime_settings);
        prime_mode = OFF;
    }

    while (fgets(line, sizeof(line), file)) {
        if (istrstr(line, "on-demand") != NULL) {
            prime_mode = ONDEMAND;
            break;
        }
        else if (istrstr(line, "on") != NULL) {
            prime_mode = ON;
            break;
        }
        else {
            prime_mode = OFF;
            break;
        }
    }
}

static void get_boot_vga(struct device **devices,
                        int cards_number,
                        unsigned int *vendor_id,
                        unsigned int *device_id) {
    int i;
    for(i = 0; i < cards_number; i++) {
        if (devices[i]->boot_vga) {
            *vendor_id = devices[i]->vendor_id;
            *device_id = devices[i]->device_id;
            break;
        }
    }
}


static void get_first_discrete(struct device **devices,
                               int cards_number,
                               struct device *device) {
    int i;
    for(i = 0; i < cards_number; i++) {
        if (!devices[i]->boot_vga) {
            memcpy(device, devices[i], sizeof(struct device));
            break;
        }
    }
}


static bool has_system_changed(struct device **old_devices,
                       struct device **new_devices,
                       int old_number,
                       int new_number) {

    bool status = false;
    int i;
    if (old_number != new_number) {
        fprintf(log_handle, "The number of cards has changed!\n");
        return 1;
    }

    for (i = 0; i < old_number; i++) {
        if ((old_devices[i]->boot_vga != new_devices[i]->boot_vga) ||
            (old_devices[i]->vendor_id != new_devices[i]->vendor_id) ||
            (old_devices[i]->device_id != new_devices[i]->device_id) ||
            (old_devices[i]->domain != new_devices[i]->domain) ||
            (old_devices[i]->bus != new_devices[i]->bus) ||
            (old_devices[i]->dev != new_devices[i]->dev) ||
            (old_devices[i]->func != new_devices[i]->func)) {
            status = true;
            break;
        }
    }

    return status;
}


static bool write_data_to_file(struct device **devices,
                              int cards_number,
                              char *filename) {
    int i;
    _cleanup_fclose_ FILE *file = NULL;
    file = fopen(filename, "w");
    if (file == NULL) {
        fprintf(log_handle, "I couldn't open %s for writing.\n",
                filename);
        return false;
    }

    for(i = 0; i < cards_number; i++) {
        fprintf(file, "%04x:%04x;%04x:%02x:%02x:%d;%d\n",
                devices[i]->vendor_id,
                devices[i]->device_id,
                devices[i]->domain,
                devices[i]->bus,
                devices[i]->dev,
                devices[i]->func,
                devices[i]->boot_vga);
    }
    fflush(file);

    return true;
}


static int get_vars(const char *line, struct device **devices,
                    int num, int desired_matches) {
    int status;

    devices[num] = malloc(sizeof(struct device));

    if (!devices[num])
        return EOF;

    status = sscanf(line, "%04x:%04x;%04x:%02x:%02x:%d;%d\n",
                    &devices[num]->vendor_id,
                    &devices[num]->device_id,
                    &devices[num]->domain,
                    &devices[num]->bus,
                    &devices[num]->dev,
                    &devices[num]->func,
                    &devices[num]->boot_vga);

    /* Make sure that we match "desired_matches" */
    if (status == EOF || status != desired_matches)
        free(devices[num]);

    return status;
}


/* Return 0 if it failed, 1 if it succeeded,
 * 2 if it created the file for the first time
 */
static int read_data_from_file(struct device **devices,
                               int *cards_number,
                               char *filename) {
    /* Read from last boot gfx */
    char line[100];
    _cleanup_fclose_ FILE *file = NULL;
    /* The number of digits we expect to match per line */
    int desired_matches = 7;
    int created = 1;

    file = fopen(filename, "r");
    if (file == NULL) {
        created = 2;
        fprintf(log_handle, "I couldn't open %s for reading.\n", filename);
        /* Create the file for the 1st time */
        file = fopen(filename, "w");
        fprintf(log_handle, "Create %s for the 1st time\n", filename);
        if (file == NULL) {
            fprintf(log_handle, "I couldn't open %s for writing.\n",
                    filename);
            return 0;
        }
        fprintf(file, "%04x:%04x;%04x:%02x:%02x:%d;%d\n",
                0, 0, 0, 0, 0, 0, 0);
        fflush(file);
        fclose(file);
        /* Try again */
        file = fopen(filename, "r");
    }

    if (file == NULL) {
        fprintf(log_handle, "I couldn't open %s for reading.\n", filename);
        return 0;
    }
    else {
        /* Use fgets so as to limit the buffer length */
        while (fgets(line, sizeof(line), file) && (*cards_number < MAX_CARDS_N)) {
            if (strlen(line) > 0) {
                /* See if we actually get all the desired digits,
                 * as per "desired_matches"
                 */
                if (get_vars(line, devices, *cards_number, desired_matches) == desired_matches) {
                    *cards_number += 1;
                }
            }
        }
    }

    return created;
}


static void add_gpu_from_file(char *filename, char *dirname, struct device **devices,
                              int *cards_number)
{
    int status = EOF;
    char path[PATH_MAX];
    char pattern[] = "u-d-c-gpu-%04x:%02x:%02x.%d-0x%04x-0x%04x";

    fprintf(log_handle, "Adding GPU from file: %s\n", filename);

    /* The number of digits we expect to match in the name */
    int desired_matches = 6;

    devices[*cards_number] = malloc(sizeof(struct device));
    if (!devices[*cards_number])
    return;

    /* The name pattern will look like the following:
     * u-d-c-gpu-0000:09:00.0-0x10de-0x1140
     */
    sprintf(path, "%s/%s", dirname, pattern);

    /* Extract the data from the string */
    status = sscanf(filename, path,
                    &devices[*cards_number]->domain,
                    &devices[*cards_number]->bus,
                    &devices[*cards_number]->dev,
                    &devices[*cards_number]->func,
                    &devices[*cards_number]->vendor_id,
                    &devices[*cards_number]->device_id);

    /* Check that we actually matched all the desired digits,
     * as per "desired_matches"
     */
    if (status == EOF || status != desired_matches) {
        free(devices[*cards_number]);
        fprintf(log_handle, "no matches, status = %d, expected = %d\n", status, desired_matches);
        return;
    }

    devices[*cards_number]->has_connected_outputs = -1;

    fprintf(log_handle, "Adding %04x:%04x in PCI:%02x@%04x:%02x:%d to the list\n",
            devices[*cards_number]->vendor_id, devices[*cards_number]->device_id,
            devices[*cards_number]->bus, devices[*cards_number]->domain,
            devices[*cards_number]->dev, devices[*cards_number]->func);

    /* Increment number of cards */
    *cards_number += 1;

    fprintf(log_handle, "Successfully detected disabled cards. Total number is %d now\n",
            *cards_number);
}


/* Look for clues of disabled cards in the directory */
void find_disabled_cards(char *dir, struct device **devices,
                         int *cards_n, void (*fcn)(char *, char *,
                         struct device **, int *))
{
    char name[PATH_MAX];
    struct dirent *dp;
    DIR *dfd;

    fprintf(log_handle, "Looking for disabled cards in %s\n", dir);

    if ((dfd = opendir(dir)) == NULL) {
        fprintf(stderr, "Error: can't open %s\n", dir);
        return;
    }

    while ((dp = readdir(dfd)) != NULL) {
        if (!starts_with(dp->d_name, "u-d-c-gpu-"))
            continue;
        if (strlen(dir)+strlen(dp->d_name)+2 > sizeof(name))
            fprintf(stderr, "Error: name %s/%s too long\n",
                    dir, dp->d_name);
        else {
            sprintf(name, "%s/%s", dir, dp->d_name);
            (*fcn)(name, dir, devices, cards_n);
        }
    }
    closedir(dfd);
}


static int nvidia_dir_filter(const struct dirent *entry)
{
    return (strncmp(entry->d_name, "nvidia", 6) == 0);
}


static int nvidia_module_filter(const struct dirent *entry)
{
    return (strncmp(entry->d_name, "nvidia.ko", 9) == 0);
}


static int amdgpu_dir_filter(const struct dirent *entry)
{
    return (strncmp(entry->d_name, "amdgpu", 6) == 0);
}


static int amdgpu_module_filter(const struct dirent *entry)
{
    return (strncmp(entry->d_name, "amdgpu.ko", 9) == 0);
}


/* Go through a directory, looking for a kernel module
 *
 */
static int search_dir_for_module(const char *kernel_path, int (*dir_filter)(const struct dirent *),
                                 int (*mod_filter)(const struct dirent *), const char *module)
{
    int status = 0;
    int n = 0, m = 0;
    struct dirent **dirlist;
    char current_path[PATH_MAX];
    char module_name[strlen(module)+4];

    snprintf(module_name, sizeof(module_name), "%s.ko", module);
    n = scandir(kernel_path, &dirlist, dir_filter, alphasort);
    if (n > 0) {
        int i = n;
        /* Check the nvidia version from high to low */
        while (i--) {
            snprintf(current_path, sizeof(current_path), "%s/%s", kernel_path, dirlist[i]->d_name);
            if (strstr(dirlist[i]->d_name, module_name) != NULL) {
                status = 1;
                fprintf(log_handle, "Found %s module in %s\n", module_name, current_path);
                break;
            }
            else {
                fprintf(log_handle, "Looking for %s modules in %s\n", module, current_path);
                m = search_dir_for_module(current_path, mod_filter, dir_filter, module);
                if (m > 0) {
                    status = 1;
                    break;
                }
            }
        }
        for (i = 0; i < n; i++) {
            if (dirlist[i] != NULL)
                free(dirlist[i]);
        }
        if (dirlist != NULL)
            free(dirlist);
        if (status)
            return status;
    }
    return status;
}


/* Check if a kernel module is available for the current kernel
 *
 * NOTE: This is only meant to check extra modules such as
 *       nvidia, or amdgpu pro.
 */
static bool is_module_available(const char *module)
{
    int (*dir_filter)(const struct dirent *);
    int (*mod_filter)(const struct dirent *);
    char kernel_path[PATH_MAX];
    struct utsname uname_data;
    int status = 0;

    if (strcmp(module, "nvidia") == 0) {
        dir_filter = nvidia_dir_filter;
        mod_filter = nvidia_module_filter;
    }
    else if (strcmp(module, "amdgpu") == 0) {
        dir_filter = amdgpu_dir_filter;
        mod_filter = amdgpu_module_filter;
    }
    else {
        fprintf(log_handle, "Checking for the %s module avilability is not supported\n", module);
        return false;
    }

    if (uname(&uname_data) < 0) {
        fprintf(stderr, "Error: uname failed\n");
        return false;
    }

    sprintf(kernel_path, "/lib/modules/%s/kernel", uname_data.release);
    fprintf(log_handle, "Looking for %s modules in %s\n", module, kernel_path);

    /* Look for the linux-restricted-modules first */
    status = search_dir_for_module(kernel_path, dir_filter, mod_filter, module);

    if (status > 0) {
        return true;
    }
    else {
        /* Look for dkms modules */
        sprintf(kernel_path, "/lib/modules/%s/updates/dkms", uname_data.release);
        fprintf(log_handle, "Looking for %s modules in %s\n", module, kernel_path);
        status = search_dir_for_module(kernel_path, dir_filter, mod_filter, module);

        return (status > 0);
    }
}


static bool is_module_loaded(const char *module) {
    bool status = false;
    char line[4096];
    _cleanup_fclose_ FILE *file = NULL;

    if (!fake_modules_path)
        file = fopen("/proc/modules", "r");
    else
        file = fopen(fake_modules_path, "r");

    if (!file) {
        fprintf(log_handle, "Error: can't open /proc/modules");
        return false;
    }

    while (fgets(line, sizeof(line), file)) {
        char *tok;
        tok = strtok(line, " \t");
        if (strcmp(tok, module) == 0) {
            status = true;
            break;
        }
    }

    return status;
}


static bool is_file(char *file) {
    struct stat stbuf;

    if (stat(file, &stbuf) == -1) {
        fprintf(log_handle, "can't access %s file\n", file);
        return false;
    }
    if (stbuf.st_mode & S_IFMT)
        return true;

    return false;
}


static bool is_dir(char *directory) {
    struct stat stbuf;

    if (stat(directory, &stbuf) == -1) {
        fprintf(log_handle, "Error: can't access %s\n", directory);
        return false;
    }
    if ((stbuf.st_mode & S_IFMT) == S_IFDIR)
        return true;
    return false;
}


static bool is_dir_empty(char *directory) {
    int n = 0;
    struct dirent *d;
    DIR *dir = opendir(directory);
    if (dir == NULL)
        return true;
    while ((d = readdir(dir)) != NULL) {
        if(++n > 2)
        break;
    }
    closedir(dir);
    if (n <= 2)
        return true;
    else
        return false;
}


static bool is_link(char *file) {
    struct stat stbuf;

    if (lstat(file, &stbuf) == -1) {
        fprintf(log_handle, "Error: can't access %s\n", file);
        return false;
    }
    if ((stbuf.st_mode & S_IFMT) == S_IFLNK)
        return true;

    return false;
}


/* See if the device is bound to a driver */
static bool is_device_bound_to_driver(struct pci_dev *info) {
    char sysfs_path[1024];
    snprintf(sysfs_path, sizeof(sysfs_path),
             "/sys/bus/pci/devices/%04x:%02x:%02x.%d/driver",
             info->domain, info->bus, info->dev, info->func);

    return(is_link(sysfs_path));
}


/* See if the device is a pci passthrough */
static bool is_device_pci_passthrough(struct pci_dev *info) {
    enum { BUFFER_SIZE = 1024 };
    char buf[BUFFER_SIZE], sysfs_path[BUFFER_SIZE], *drv, *name;
    ssize_t length;

    length = snprintf(sysfs_path, sizeof(sysfs_path),
                      "/sys/bus/pci/devices/%04x:%02x:%02x.%d/driver",
                      info->domain, info->bus, info->dev, info->func);
    if (length < 0 || length >= sizeof(sysfs_path))
        return false;

    length = readlink(sysfs_path, buf, sizeof(buf)-1);

    if (length != -1) {
        buf[length] = '\0';

        if ((drv = strrchr(buf, '/')))
            name = drv+1;
        else
            name = buf;

        if (strcmp(name, "pci-stub") == 0 || strcmp(name, "pciback") == 0)
            return true;
    }
    return false;
}


/* Check the drm connector status */
static bool is_connector_connected(const char *connector) {
    bool status = false;
    char line[50];
    _cleanup_fclose_ FILE *file = NULL;

    file = fopen(connector, "r");

    if (!file)
        return false;

    while (fgets(line, sizeof(line), file)) {
        char *tok;
        tok = strtok(line, " \t");
        if (starts_with(tok, "connected")) {
            status = true;
            break;
        }
    }

    return status;
}


/* Count the number of outputs connected to the card */
int count_connected_outputs(const char *device_name) {
    char name[PATH_MAX];
    struct dirent *dp;
    DIR *dfd;
    int connected_outputs = 0;
    char drm_dir[] = "/sys/class/drm";

    if ((dfd = opendir(drm_dir)) == NULL) {
        fprintf(stderr, "Warning: can't open %s\n", drm_dir);
        return connected_outputs;
    }

    while ((dp = readdir(dfd)) != NULL) {
        if (!starts_with(dp->d_name, device_name))
            continue;
        if (strlen(drm_dir)+strlen(dp->d_name)+2 > sizeof(name))
            fprintf(stderr, "Warning: name %s/%s too long\n",
                    drm_dir, dp->d_name);
        else {
            /* Open the file for the connector */
            snprintf(name, sizeof(name), "%s/%s/status", drm_dir, dp->d_name);
            name[sizeof(name) - 1] = 0;
            if (is_connector_connected(name)) {
                fprintf(log_handle, "output %d:\n", connected_outputs);
                fprintf(log_handle, "\t%s\n", dp->d_name);
                connected_outputs++;
            }
        }
    }
    closedir(dfd);

    return connected_outputs;
}


/* See if the drm device created by a driver has any connected outputs.
 * Return 1 if outputs are connected, 0 if they're not, -1 if unknown
 */
static int has_driver_connected_outputs(const char *driver) {
    DIR *dir;
    struct dirent* dir_entry;
    char path[PATH_MAX];
    int fd = 1;
    drmVersionPtr version;
    int connected_outputs = 0;
    int driver_match = 0;
    char dri_dir[] = "/dev/dri";
    _cleanup_free_ char *device_path= NULL;

    if (NULL == (dir = opendir(dri_dir))) {
        fprintf(log_handle, "Error : Failed to open %s\n", dri_dir);
        return -1;
    }

    /* Keep looking until we find the device for the driver */
    while ((dir_entry = readdir(dir))) {
        if (!starts_with(dir_entry->d_name, "card"))
            continue;

        snprintf(path, sizeof(path), "%s/%s", dri_dir, dir_entry->d_name);
        path[sizeof(path) - 1] = 0;
        fd = open(path, O_RDWR);
        if (fd) {
            if ((version = drmGetVersion(fd))) {
                /* Let's use strstr to catch the different backported
                 * kernel modules
                 */
                if (driver && strstr(version->name, driver) != NULL) {
                    fprintf(log_handle, "Found \"%s\", driven by \"%s\"\n",
                           path, version->name);
                    driver_match = 1;
                    device_path = malloc(strlen(dir_entry->d_name)+1);
                    if (device_path)
                        strcpy(device_path, dir_entry->d_name);
                    drmFreeVersion(version);
                    break;
                }
                else {
                    fprintf(log_handle, "Skipping \"%s\", driven by \"%s\"\n",
                            path, version->name);
                    drmFreeVersion(version);
                    close(fd);
                }
            }
        }
        else {
            fprintf(log_handle, "Error: can't open fd for %s\n", path);
            continue;
        }
    }

    closedir(dir);

    close(fd);

    if (!driver_match)
        return -1;

    if (!device_path)
        return -1;

    connected_outputs = count_connected_outputs(device_path);

    fprintf(log_handle, "Number of connected outputs for %s: %d\n", path, connected_outputs);

    return (connected_outputs > 0);
}


/* Add information on connected outputs */
static void add_connected_outputs_info(struct device **devices,
                                       int cards_n) {
    int i;
    int amdgpu_has_outputs = has_driver_connected_outputs("amdgpu");
    int radeon_has_outputs = has_driver_connected_outputs("radeon");
    int nouveau_has_outputs = has_driver_connected_outputs("nouveau");
    int intel_has_outputs = has_driver_connected_outputs("i915");

    for(i = 0; i < cards_n; i++) {
        if (devices[i]->vendor_id == INTEL)
            devices[i]->has_connected_outputs = intel_has_outputs;
        else if (devices[i]->vendor_id == AMD)
            devices[i]->has_connected_outputs = ((radeon_has_outputs != -1) ? radeon_has_outputs
                                                 : amdgpu_has_outputs);
        else if (devices[i]->vendor_id == NVIDIA)
            devices[i]->has_connected_outputs = nouveau_has_outputs;
        else
            devices[i]->has_connected_outputs = -1;
    }
}


/* Check if any outputs are still connected to card0 */
static bool requires_offloading(struct device **devices,
                                int cards_n) {

    /* Let's check only /dev/dri/card0 and look
     * for the boot_vga device.
     */
    int i;
    bool status = false;
    for(i = 0; i < cards_n; i++) {
        if (devices[i]->boot_vga) {
            status = (devices[i]->has_connected_outputs == 1);
            break;
        }
    }

    if (status) {
        if (!exists_not_empty(prime_settings)) {
            fprintf(log_handle, "No prime-settings found. "
                                "Assuming prime is not set "
                                "to ON (ONDEMAND could be on).\n");
            return false;
        }

        get_prime_action();
        status = (prime_mode == ON);
    }

    return status;
}


/* Set permanent settings for offloading */
static bool set_offloading(void) {
    _cleanup_fclose_ FILE *file = NULL;

    if (dry_run)
        return true;

    file = fopen(OFFLOADING_CONF, "w");
    if (file != NULL) {
        fprintf(file, "ON\n");
        fflush(file);
        return true;
    }

    return false;
}


/* Move the log */
static bool move_log(void) {
    int status;
    char backup[200];
    char buffer[80];
    time_t rawtime;
    struct tm *info;

    time(&rawtime);
    info = localtime(&rawtime);

    strftime(buffer, 80, "%H%M%m%d%Y", info);
    snprintf(backup, sizeof(backup), "%s.%s", log_file, buffer);

    status = rename(log_file, backup);
    if (!status) {
        status = unlink(log_file);
        if (!status)
            return false;
        else
            return true;
    }

    return true;
}


static bool create_prime_settings(const char *prime_settings) {
    int major, minor, extra;
    _cleanup_fclose_ FILE *file = NULL;

    fprintf(log_handle, "Trying to create new settings for prime. Path: %s\n",
            prime_settings);

    file = fopen(prime_settings, "w");
    if (file == NULL) {
        fprintf(log_handle, "I couldn't open %s for writing.\n",
                prime_settings);
        return false;
    }
    /* Make on-demand the default if
     * runtimepm is supported.
     */
    if (nvidia_runtimepm_supported) {
        /* Set prime to "on-demand" */
        fprintf(file, "on-demand\n");
    }
    else {
        if (get_nvidia_driver_version(&major, &minor, &extra)) {
            if (major >= 450) {
                /* Set prime to "on-demand" */
                fprintf(file, "on-demand\n");
            }
            else {
                /* Set prime to "on" */
                fprintf(file, "on\n");
            }
        }
    }

    fflush(file);

    return true;
}


static bool get_nvidia_driver_version(int *major, int *minor, int *extra) {

    int status;
    size_t len = 0;
    _cleanup_free_ char *driver_version = NULL;
    _cleanup_fclose_ FILE *file = NULL;

    /* Check the driver version */
    file = fopen(nvidia_driver_version_path, "r");
    if (file == NULL) {
        fprintf(log_handle, "can't open %s\n", nvidia_driver_version_path);
        return false;
    }
    if (getline(&driver_version, &len, file) == -1) {
        fprintf(log_handle, "can't get line from %s\n", nvidia_driver_version_path);
        return false;
    }

    status = sscanf(driver_version, "%d.%d.%d\n", major, minor, extra);

    /* Make sure that we match "desired_matches" */
    if (status == EOF || status < 2 ) {
        fprintf(log_handle, "Warning: couldn't get the driver version from %s\n",
                nvidia_driver_version_path);
        return false;
    }

    if (status == 2)
        *extra = -1;

    return true;
}


static bool get_kernel_version(int *major, int *minor, int *extra) {
    struct utsname buffer;
    int status;
    _cleanup_free_ char *version = NULL;

    errno = 0;
    if (uname(&buffer) != 0) {
        return false;
    }

    status = sscanf(buffer.release, "%d.%d.%d\n", major, minor, extra);

    /* Make sure that we match "desired_matches" */
    if (status == EOF || status != 3 ) {
        fprintf(log_handle, "Warning: couldn't get the kernel version from %s\n",
                buffer.release);
        return false;
    }

    return true;
}


static char* get_module_version(const char *module_name) {
    struct kmod_ctx *ctx = NULL;
    struct kmod_module *mod = NULL;
    struct kmod_list *l, *list = NULL;
    int err;
    char *version = NULL;

    ctx = kmod_new(NULL, NULL);
    err = kmod_module_new_from_name(ctx, module_name, &mod);
    if (err < 0) {
        fprintf(log_handle, "can't acquire module via kmod");
        goto get_module_version_clean;
    }

    err = kmod_module_get_info(mod, &list);
    if (err < 0) {
        fprintf(log_handle, "can't get module info via kmod");
        goto get_module_version_clean;
    }

    kmod_list_foreach(l, list) {
        const char *key = kmod_module_info_get_key(l);

        if (strcmp(key, "version") == 0) {
            version = strdup(kmod_module_info_get_value(l));
            break;
        }
    }

get_module_version_clean:
    if (list)
        kmod_module_info_free_list(list);
    if (mod)
        kmod_module_unref(mod);
    if (ctx)
        kmod_unref(ctx);

    return version;
}


static bool is_module_versioned(const char *module_name) {
    _cleanup_free_ const char *version = NULL;

    if (dry_run)
        return false;

    version = get_module_version(module_name);

    return version ? true : false;
}


static bool run_amdgpu_pro_px(amdgpu_pro_px_action action) {
    int status = 0;
    char command[100];

    switch (action) {
    case MODE_POWERSAVING:
        snprintf(command, sizeof(command), "%s --%s", amdgpu_pro_px_file, "mode powersaving");
        fprintf(log_handle, "Enabling power saving mode for amdgpu-pro");
        break;
    case MODE_PERFORMANCE:
        snprintf(command, sizeof(command), "%s --%s", amdgpu_pro_px_file, "mode performance");
        fprintf(log_handle, "Enabling performance mode for amdgpu-pro");
        break;
    case RESET:
        snprintf(command, sizeof(command), "%s --%s", amdgpu_pro_px_file, "reset");
        fprintf(log_handle, "Resetting the script changes for amdgpu-pro");
        break;
    case ISPX:
        snprintf(command, sizeof(command), "%s --%s", amdgpu_pro_px_file, "ispx");
        break;
    }

    if (dry_run) {
        fprintf(log_handle, "%s\n", command);
        return true;
    }

    status = system(command);

    return (status == 0);
}


static bool create_prime_outputclass(void) {
    _cleanup_fclose_ FILE *file = NULL;
    _cleanup_free_ char *multiarch = NULL;
    char xorg_d_custom[PATH_MAX];

    snprintf(xorg_d_custom, sizeof(xorg_d_custom), "%s/11-nvidia-prime.conf",
             xorg_conf_d_path);

    multiarch = get_system_architecture();
    if (!multiarch)
        return false;

    fprintf(log_handle, "Creating %s\n", xorg_d_custom);
    file = fopen(xorg_d_custom, "w");
    if (!file) {
        fprintf(log_handle, "Error while creating %s\n", xorg_d_custom);
    }
    else {
        fprintf(file,
                "# DO NOT EDIT. AUTOMATICALLY GENERATED BY gpu-manager\n\n"
                "Section \"OutputClass\"\n"
                "    Identifier \"Nvidia Prime\"\n"
                "    MatchDriver \"nvidia-drm\"\n"
                "    Driver \"nvidia\"\n"
                "    Option \"AllowEmptyInitialConfiguration\"\n"
                "    Option \"IgnoreDisplayDevices\" \"CRT\"\n"
                "    Option \"PrimaryGPU\" \"Yes\"\n"
                "    ModulePath \"/lib/%s/nvidia/xorg\"\n"
                "EndSection\n\n",
                multiarch);

        fflush(file);
        return true;
    }

    return false;
}

static bool create_offload_serverlayout(void) {
    _cleanup_fclose_ FILE *file = NULL;
    char xorg_d_custom[PATH_MAX];

    snprintf(xorg_d_custom, sizeof(xorg_d_custom), "%s/11-nvidia-offload.conf",
             xorg_conf_d_path);

    fprintf(log_handle, "Creating %s\n", xorg_d_custom);
    file = fopen(xorg_d_custom, "w");
    if (!file) {
        fprintf(log_handle, "Error while creating %s\n", xorg_d_custom);
    }
    else {
        fprintf(file,
                "# DO NOT EDIT. AUTOMATICALLY GENERATED BY gpu-manager\n\n"
                "Section \"ServerLayout\"\n"
                "    Identifier \"layout\"\n"
                "    Option \"AllowNVIDIAGPUScreens\"\n"
                "EndSection\n\n");

        fflush(file);
        return true;
    }

    return false;
}

/* Attempt to remove a file named "name" in xorg_conf_d_path. Returns 0 if the
 * file is successfully removed, or -errno on failure. */
static int remove_xorg_d_custom_file(const char *name) {
    char path[PATH_MAX];
    struct stat st;

    snprintf(path, sizeof(path), "%s/%s", xorg_conf_d_path, name);
    if (stat(path, &st) == 0) {
        fprintf(log_handle, "Removing %s\n", path);
        if (unlink(path) == 0) {
            return 0;
        }
    }

    return -errno;
}

static int remove_prime_outputclass(void) {
    return remove_xorg_d_custom_file("11-nvidia-prime.conf");
}

static int remove_offload_serverlayout(void) {
    return remove_xorg_d_custom_file("11-nvidia-offload.conf");
}


static bool create_runtime_file(const char *name) {
    _cleanup_fclose_ FILE *file = NULL;
    char path[PATH_MAX];

    snprintf(path, sizeof(path),
             "%s/%s", gpu_detection_path, name);

    fprintf(log_handle, "Trying to create new file: %s\n",
            path);

    file = fopen(path, "w");
    if (file == NULL) {
        fprintf(log_handle, "I couldn't open %s for writing.\n",
                path);
        return false;
    }
    fprintf(file, "yes\n");
    fflush(file);

    return true;
}


static bool create_nvidia_runtime_config(void) {
    _cleanup_fclose_ FILE *file = NULL;
    char path[] = "/lib/modprobe.d/nvidia-runtimepm.conf";

    fprintf(log_handle, "Trying to create new file: %s\n",
            path);

    file = fopen(path, "w");
    if (file == NULL) {
        fprintf(log_handle, "I couldn't open %s for writing.\n",
                path);
        return false;
    }
    fprintf(file, "options nvidia \"NVreg_DynamicPowerManagement=0x02\"\n");
    fflush(file);

    return true;
}


static int remove_nvidia_runtime_config(void) {
    struct stat st;
    char path[] = "/lib/modprobe.d/nvidia-runtimepm.conf";

    if (stat(path, &st) == 0) {
        fprintf(log_handle, "Trying to remove file: %s\n",
        path);
        if (unlink(path) == 0) {
            return 0;
        }
    }
    return -errno;
}


static bool manage_power_management(const struct device *device, bool enabled) {
    _cleanup_fclose_ FILE *file = NULL;
    char pci_device_path[PATH_MAX];

    snprintf(pci_device_path, sizeof(pci_device_path),
             "/sys/bus/pci/devices/%04x:%02x:%02x.%x/power/control",
             (unsigned int)device->domain,
             (unsigned int)device->bus,
             (unsigned int)device->dev,
             (unsigned int)device->func);

    fprintf(log_handle, "Setting power control to \"%s\" in %s\n", enabled ? "auto" : "on", pci_device_path);
    file = fopen(pci_device_path, "w");
    if (!file) {
        fprintf(log_handle, "Error while opening %s\n", pci_device_path);
        return false;
    }
    else {
        fputs(enabled ? "auto\n" : "on\n", file);

        fflush(file);
        return true;
    }
}

static void enable_power_management(const struct device *device) {
    manage_power_management(device, true);
    if (nvidia_runtimepm_supported && ! nvidia_runtimepm_enabled) {
        create_nvidia_runtime_config();
    }
}

static void disable_power_management(const struct device *device) {
    manage_power_management(device, false);
    remove_nvidia_runtime_config();
}

static bool unload_nvidia(void) {
    unload_module("nvidia-drm");
    unload_module("nvidia-uvm");
    unload_module("nvidia-modeset");

    return unload_module("nvidia");
}

static char* get_pid_by_name(const char *name) {
    char command[100];
    char *pid = NULL;

    snprintf(command, sizeof(command),
             "/bin/pidof %s",
             name);
    fprintf(log_handle, "Calling %s\n", command);
    pid = get_output(command, NULL, NULL);

    if (!pid) {
        fprintf(log_handle, "Info: no PID found for %s.\n",
                name);
        return NULL;
    }

    return pid;
}


static long get_uid_of_pid(const char *pid) {
    char path[PATH_MAX];

    _cleanup_free_ char *line = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    size_t len = 0;
    size_t read;
    char pattern[] = "Uid:";
    long uid = -1;

    snprintf(path, sizeof(path),
             "/proc/%s/status",
             pid);
    fprintf(log_handle, "Opening %s\n", path);

    file = fopen(path, "r");
    if (file == NULL) {
        fprintf(log_handle, "Error: can't open %s\n", path);
        return -1;
    }
    while ((read = getline(&line, &len, file)) != -1) {
        if (istrstr(line, pattern) != NULL) {
            fprintf(log_handle, "found \"%s\"\n", line);
            if (strncmp(line, "Uid:", 4) == 0) {
                uid = strtol(line + 4, NULL, 10);
                fprintf(log_handle, "Found %ld\n", uid);
            }
        }
    }
    return uid;
}


static char* get_user_from_uid(const long uid) {
    size_t read;
    char *token, *str;
    char pattern[PATH_MAX];
    char *user = NULL;
    size_t len = 0;
    _cleanup_free_ char *line = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    _cleanup_free_ char *tofree = NULL;

    snprintf(pattern, sizeof(pattern),
             "%ld",
             uid);
    fprintf(log_handle, "Looking for %s\n", pattern);

    file = fopen("/etc/passwd", "r");
    if (file == NULL)
         return NULL;
    while ((read = getline(&line, &len, file)) != -1 && (user == NULL)) {
        if (istrstr(line, pattern) != NULL) {
            tofree = str = strdup(line);
            /* Get the first result
             * gdm:x:120:125:Gnome Display Manager:/var/lib/gdm3:/bin/false
             */
            while( (token = strsep(&str, ":")) != NULL ) {
                user = strdup(token);
                fprintf(log_handle, "USER: %s\n", user);
                break;
            }
        }
    }
    return user;
}


/* Check a strings with pids, and find the gdm session */
static long find_pid_main_session(const char *pid_str) {
    _cleanup_free_ char *tofree = NULL;
    _cleanup_free_ char *user = NULL;
    long uid = -1;
    char *token, *str;
    long pid = -1;

    tofree = str = strdup(pid_str);
    while( (token = strsep(&str," ")) != NULL ) {
        if ( (uid = get_uid_of_pid(token)) >= 0) {
            fprintf(log_handle, "Found: %s %ld\n", token, uid);
            /*look up the UID in /etc/passwd */
            user = get_user_from_uid(uid);
            fprintf(log_handle, "User: %s UID: %ld\n", user, uid);
            if ((user != NULL) && (strcmp(user, "gdm") == 0)) {
                pid = strtol(token, NULL, 10);
                break;
            }
        }
    }
    return pid;
}


static long get_gdm_session_pid(const char* display_server) {
    _cleanup_free_ char *pid_str = NULL;
    long pid = -1;

    pid_str = get_pid_by_name(display_server);
    if (!pid_str) {
        fprintf(log_handle, "INFO: no PID found for %s.\n",
                display_server);
        return -1;
    }

    fprintf(log_handle, "INFO: found PID(s) %s for %s.\n",
                    pid_str, display_server);

    pid = find_pid_main_session(pid_str);

    fprintf(log_handle, "INFO: found PID %ld for Gdm main %s session.\n",
            pid, display_server);

    return pid;
}


/* Kill the main display session created by Gdm 3 */
static bool kill_main_display_session (void) {
    int i;
    _cleanup_free_ char *final_pid = NULL;
    char command[100];
    char server[] = "Xwayland";
    long pid = -1;
    int status = 0;
    /* try with Xwayland first */
    char *servers[2] = {"Xwayland", "Xorg"};

    if (!dry_run) {
        for(i = 0; i < 2; i++) {
            pid = get_gdm_session_pid(servers[i]);
            if (pid <= 0)
                fprintf(log_handle, "Info: no PID found for %s.\n", servers[i]);
            else
                break;
        }
        if (pid <= 0)
            return false;

        fprintf(log_handle, "Info: found PID(s) %ld for %s.\n",
                pid, server);

        /* Kill the session */
        snprintf(command, sizeof(command), "kill -KILL %ld", pid);
        fprintf(log_handle, "Calling %s\n", command);
        status = system(command);
    }
    return (status == 0);
}


static bool enable_prime(const char *prime_settings,
                        const struct device *device,
                        struct device **devices,
                        int cards_n) {
    int major, minor, extra;
    bool status = false;
    int tries = 0;
    /* Check if prime_settings is available
     * File doesn't exist or empty
     */
    if (!exists_not_empty(prime_settings)) {
        fprintf(log_handle, "Warning: no settings for prime can be found in %s.\n",
                prime_settings);

       /* Try to create the file */
        if (!create_prime_settings(prime_settings)) {
            fprintf(log_handle, "Error: failed to create %s\n",
                    prime_settings);
            return false;
        }
    }

    get_prime_action();
    if (prime_mode == ON) {
prime_on_fallback:
        /* Create an OutputClass just for PRIME, to override
         * the default NVIDIA settings
         */
        create_prime_outputclass();
        /* Remove the ServerLayout */
        remove_offload_serverlayout();
        disable_power_management(device);
        if (!is_module_loaded("nvidia"))
            load_module("nvidia");
    }
    else if (prime_mode == ONDEMAND) {
        if (get_nvidia_driver_version(&major, &minor, &extra)) {
            if (major < 450) {
                /* Set prime to "on" */
                fprintf(log_handle, "Info: falling back to on mode for PRIME, since driver series %d < 450.\n",
                major);
                create_prime_settings(prime_settings);
                goto prime_on_fallback;
            }
        }

        /* Create the ServerLayout required to enabling offload
         * for NVIDIA.
         */
        create_offload_serverlayout();
        /* Remove the OutputClass */
        remove_prime_outputclass();
        enable_power_management(device);
        if (!is_module_loaded("nvidia"))
            load_module("nvidia");
    }
    else {
        /* Remove the OutputClass and ServerLayout */
        remove_prime_outputclass();
        remove_offload_serverlayout();

unload_again:
        /* Unload the NVIDIA modules and enable pci power management */
        if (is_module_loaded("nvidia")) {
            status = unload_nvidia();

            if (!status && is_module_loaded("nvidia")) {
                fprintf(log_handle, "Warning: failure to unload the nvidia modules.\n");
                if (tries == 0) {
                    fprintf(log_handle, "Info: killing X...\n");
                    status = kill_main_display_session();
                    if (status) {
                        tries++;
                        goto unload_again;
                    }
                }
                else {
                    fprintf(log_handle, "Error: giving up on unloading nvidia...\n");
                    return false;
                }
            }
        }
        /* Set power control to "auto" to save power */
        enable_power_management(device);
    }

    return true;
}


static bool json_find_feature_in_array(char* feature, json_value* value)
{
    int length, x;
    if (value == NULL) {
        return false;
    }

    length = value->u.array.length;
    fprintf(log_handle, "Looking for availability of \"%s\" feature\n", feature);
    for (x = 0; x < length; x++) {
        /* fprintf(log_handle, "feature string: %s\n", value->u.array.values[x]->u.string.ptr); */
        if (strcmp(value->u.array.values[x]->u.string.ptr, feature) == 0) {
            fprintf(log_handle, "\"%s\" feature found\n", feature);
            return true;
        }
    }
    fprintf(log_handle, "\"%s\" feature not found\n", feature);
    return false;
}


static bool json_process_object_for_device_id(int id, json_value* value)
{
    int length, x;
    if (value == NULL) {
        return false;
    }
    length = value->u.object.length;
    for (x = 0; x < length; x++) {
        if (strcmp(value->u.object.values[x].name, "devid") == 0) {
            if (strtol(value->u.object.values[x].value->u.string.ptr, NULL, 16) == id) {
                fprintf(log_handle, "Device ID %s found in json file\n", value->u.object.values[x].value->u.string.ptr);
                return true;
            }
        }
    }

    return false;
}


static bool json_find_feature_in_object(char* feature, json_value* value)
{
    int length, x;
    if (value == NULL) {
            return false;
    }
    length = value->u.object.length;
    for (x = 0; x < length; x++) {
        if (strcmp(value->u.object.values[x].name, "name") == 0) {
            fprintf(log_handle, "Device name: %s\n", value->u.object.values[x].value->u.string.ptr);
        }
        if (strcmp(value->u.object.values[x].name, "features") == 0) {
            /* fprintf(log_handle, "features: %s\n", value->u.object.values[x].value->u.string.ptr);*/
            return (json_find_feature_in_array(feature, value->u.object.values[x].value));
        }
    }
    return false;
}


static json_value* json_find_device_id_in_array(int id, json_value* value)
{
    int length, x;
    if (value == NULL) {
            return NULL;
    }
    length = value->u.array.length;
    for (x = 0; x < length; x++) {
        if (json_process_object_for_device_id(id, value->u.array.values[x])) {
            /*fprintf(log_handle, "Device ID found in object %d\n", x);*/
            return value->u.array.values[x];
            break;
        }
    }
    fprintf(log_handle, "Device ID \"0x%x\" not found in json file\n", id);

    return NULL;
}


static json_value* json_find_device_id(int id, json_value* value)
{
    fprintf(log_handle, "Looking for device ID \"0x%x\" in json file\n", id);
    int length, x;
    json_value* chips = NULL;
    if (value == NULL) {
        return NULL;
    }


    length = value->u.object.length;
    for (x = 0; x < length; x++) {
        /*fprintf(log_handle, "object[%d].name = %s\n", x, value->u.object.values[x].name);*/
        if (strcmp(value->u.object.values[x].name, "chips") == 0) {
            chips = value->u.object.values[x].value;
            /*fprintf(log_handle, "Chips found\n");*/
        }

    }

    if (chips) {
        /*fprintf(log_handle, "processing chips\n");*/
        return (json_find_device_id_in_array(id, chips));
    }
    else {
        fprintf(log_handle, "Error: json chips array not found. Aborting\n");
    }
    return NULL;
}


static bool find_supported_gpus_json(char **json_file){
    int major, minor, extra;
    _cleanup_fclose_ FILE *file = NULL;

    if (get_nvidia_driver_version(&major, &minor, &extra)) {
        if (major >= 450) {
            if (extra > -1) {
                asprintf(json_file, "/usr/share/doc/nvidia-driver-%d-server/supported-gpus.json",
                 major);
            }
            else {
                asprintf(json_file, "/usr/share/doc/nvidia-driver-%d/supported-gpus.json",
                 major);
            }
            fprintf(log_handle, "Found json file: %s\n", *json_file);
        }
    }
    else {
        fprintf(log_handle, "Warning: cannot check the NVIDIA driver major version\n");
        return false;
    }

    return true;
}


/* Look up the device ID in the json file for RTD3 support */
static bool is_nv_runtimepm_supported(int nv_device_id) {
    _cleanup_free_ char *json_file = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    struct stat filestatus;
    int file_size;
    char* file_contents;
    json_char* json;
    json_value* value;
    json_value* device_value;
    int major, minor, extra;

    bool supported = false;

    if (is_file(RUNTIMEPM_OVERRIDE)) {
        fprintf(log_handle, "%s found. Will try runtimepm if the kernel supports it.\n", RUNTIMEPM_OVERRIDE);
        supported = true;
    }
    else if(find_supported_gpus_json(&json_file)) {
        if ( stat(json_file, &filestatus) != 0) {
            fprintf(log_handle, "File %s not found\n", json_file);
            return false;
        }

        file_size = filestatus.st_size;
        file_contents = (char*)malloc(filestatus.st_size);
        if (file_contents == NULL) {
            fprintf(log_handle, "Memory error: unable to allocate %d bytes\n", file_size);
            return false;
        }

        file = fopen(json_file, "rt");
        if (file == NULL) {
            fprintf(log_handle, "Unable to open %s\n", json_file);
            free(file_contents);
            return false;
        }
        if (fread(file_contents, file_size, 1, file) != 1 ) {
            fprintf(log_handle, "Unable t read content of %s\n", json_file);
            free(file_contents);
            return false;
        }

        json = (json_char*)file_contents;
        value = json_parse(json,file_size);

        if (value == NULL) {
            fprintf(log_handle, "Unable to parse data\n");
            free(file_contents);
            return false;
        }

        device_value = json_find_device_id(nv_device_id, value);
        supported = json_find_feature_in_object("runtimepm", device_value);

        device_value = NULL;
        json_value_free(value);
        free(file_contents);
    }
    else {
        fprintf(log_handle, "Support for runtimepm not detected.\n"
                "You can override this check at your own risk by creating the %s file.\n",
                RUNTIMEPM_OVERRIDE);
        return false;
    }

    if (! get_kernel_version(&major, &minor, &extra)) {
        fprintf(log_handle, "Failed to check kernel version. Disabling runtimepm.\n");
        return false;
    }

    if (major > 4 || ((major == 4) && (minor >= 18))) {
        fprintf(log_handle, "Linux %d.%d detected.\n", major, minor);
    }
    else {
        fprintf(log_handle, "Linux %d.%d detected. Linux 4.18 or newer is required for runtimepm\n",
                major, minor);
        supported = false;
    }

    return supported;
}


/* Check the procfs entry for the NVIDIA GPU to check the RTD3 status */
static bool is_nv_runtimepm_enabled(struct pci_dev *device) {
    size_t read;
    char proc_gpu_path[PATH_MAX];
    _cleanup_fclose_ FILE *file = NULL;
    _cleanup_free_ char *line = NULL;
    char pattern[] = "Runtime D3 status:";
    size_t len = 0;
    size_t pattern_len = strlen(pattern);


    snprintf(proc_gpu_path, sizeof(proc_gpu_path),
             "/proc/driver/nvidia/gpus/%04x:%02x:%02x.%x/power",
             (unsigned int)device->domain,
             (unsigned int)device->bus,
             (unsigned int)device->dev,
             (unsigned int)device->func);

    fprintf(log_handle, "Checking power status in %s\n", proc_gpu_path);
    file = fopen(proc_gpu_path, "r");
    if (!file) {
        fprintf(log_handle, "Error while opening %s\n", proc_gpu_path);
        return false;
    }
    else {
        while ((read = getline(&line, &len, file)) != -1) {
            if (istrstr(line, pattern) != NULL) {
                fprintf(log_handle, "%s", line);
                if (strncmp(line, pattern, pattern_len) == 0) {
                    if (istrstr(line, "enabled") != NULL) {
                        return true;
                    }
                    else {
                        return false;
                    }
                }
            }
        }
    }
    return false;
}

static bool is_laptop(void) {
    /*
        Chassis types:

        01 Other
        02 Unknown
        03 Desktop
        04 Low Profile Desktop
        05 Pizza Box
        06 Mini Tower
        07 Tower
        08 Portable
        09 Laptop
        10 Notebook
        11 Hand Held
        12 Docking Station
        13 All In One
        14 Sub Notebook
        15 Space-saving
        16 Lunch Box
        17 Main Server Chassis
        18 Expansion Chassis
        19 Sub Chassis
        20 Bus Expansion Chassis
        21 Peripheral Chassis
        22 RAID Chassis
        23 Rack Mount Chassis
        24 Sealed-case PC
        25 Multi-system
        26 CompactPCI
        27 AdvancedTCA
        28 Blade
        29 Blade Enclosing
        30 Tablet
        31 Convertible
        32 Detachable
        33 IoT Gateway
        34 Embedded PC
        35 Mini PC
        36 Stick PC
    */

    _cleanup_free_ char *line = NULL;
    _cleanup_fclose_ FILE *file = NULL;
    size_t len = 0;
    size_t read;
    int code = 0;
    int status;
    bool is_laptop = false;

    file = fopen(CHASSIS_PATH, "r");
    if (file == NULL) {
        fprintf(log_handle, "Error: can't open %s\n", CHASSIS_PATH);
        return false;
    }
    else {
        while ((read = getline(&line, &len, file)) != -1) {
            status = sscanf(line, "%d\n", &code);
            if (status) {
                fprintf(log_handle, "Chassis type: \"%d\"\n", code);

                switch (code)
                {
                    case 8:
                    case 9:
                    case 10:
                    case 31:
                        fprintf(log_handle,"Laptop detected\n");
                        is_laptop = true;
                        break;

                    default:
                        fprintf(log_handle,"Laptop not detected\n");
                        break;
                }

                break;
            }
        }
    }
    return is_laptop;
}


int main(int argc, char *argv[]) {

    int opt, i;
    char *fake_lspci_file = NULL;
    char *new_boot_file = NULL;

    static int fake_offloading = 0;
    static int fake_module_available = 0;
    static int fake_module_versioned = 0;
    static int backup_log = 0;

    bool has_intel = false, has_amd = false, has_nvidia = false;
    bool has_changed = false;
    bool nvidia_loaded = false,
         intel_loaded = false, radeon_loaded = false,
         amdgpu_loaded = false, nouveau_loaded = false;
    bool nvidia_unloaded = false;
    bool nvidia_blacklisted = false,
         radeon_blacklisted = false, amdgpu_blacklisted = false,
         nouveau_blacklisted = false;
    bool nvidia_kmod_available = false,
         amdgpu_kmod_available = false;
    bool amdgpu_versioned = false;
    bool amdgpu_pro_px_installed = false;
    bool amdgpu_is_pro = false;
    int offloading = false;
    int status = 0;

    /* Vendor and device id (boot vga) */
    unsigned int boot_vga_vendor_id = 0, boot_vga_device_id = 0;

    /* The current number of cards */
    int cards_n = 0;

    /* The number of cards from last boot*/
    int last_cards_n = 0;

    /* Variables for pci capabilities */
    bool d3hot = false;
    bool d3cold = false;
    struct pci_access *pacc = NULL;
    struct pme_dev *pm_dev = NULL;
    struct pci_dev *dev = NULL;

    /* Store the devices here */
    struct device *current_devices[MAX_CARDS_N];
    struct device *old_devices[MAX_CARDS_N];

    /* Device information (discrete) */
    struct device discrete_device = { 0 };


    while (1) {
        static struct option long_options[] =
        {
        /* These options set a flag. */
        {"dry-run", no_argument,     &dry_run, 1},
        {"fake-requires-offloading", no_argument, &fake_offloading, 1},
        {"fake-no-requires-offloading", no_argument, &fake_offloading, 0},
        {"fake-module-is-available", no_argument, &fake_module_available, 1},
        {"fake-module-is-not-available", no_argument, &fake_module_available, 0},
        {"backup-log", no_argument, &backup_log, 1},
        {"fake-module-is-versioned", no_argument, &fake_module_versioned, 1},
        /* These options don't set a flag.
          We distinguish them by their indices. */
        {"log",  required_argument, 0, 'l'},
        {"fake-lspci",  required_argument, 0, 'f'},
        {"last-boot-file", required_argument, 0, 'b'},
        {"new-boot-file", required_argument, 0, 'n'},
        {"fake-modules-path", required_argument, 0, 'm'},
        {"gpu-detection-path", required_argument, 0, 's'},
        {"prime-settings", required_argument, 0, 'z'},
        {"dmi-product-version-path", required_argument, 0, 'h'},
        {"dmi-product-name-path", required_argument, 0, 'i'},
        {"nvidia-driver-version-path", required_argument, 0, 'j'},
        {"modprobe-d-path", required_argument, 0, 'k'},
        {"xorg-conf-d-path", required_argument, 0, 'a'},
        {"amdgpu-pro-px-file", required_argument, 0, 'w'},
        {0, 0, 0, 0}
        };
        /* getopt_long stores the option index here. */
        int option_index = 0;

        opt = getopt_long (argc, argv, "a:b:c:d:f:g:h:i:j:k:l:m:n:o:p:q:r:s:t:x:y:z:w:",
                        long_options, &option_index);

        /* Detect the end of the options. */
        if (opt == -1)
         break;

        switch (opt) {
            case 0:
                if (long_options[option_index].flag != 0)
                    break;
                printf("option %s", long_options[option_index].name);
                if (optarg)
                    printf(" with arg %s", optarg);
                printf("\n");
                break;
            case 'a':
                xorg_conf_d_path = strdup(optarg);
                if (!xorg_conf_d_path)
                    abort();
                break;
            case 'l':
                /* printf("option -l with value '%s'\n", optarg); */
                log_file = malloc(strlen(optarg) + 1);
                if (log_file)
                    strcpy(log_file, optarg);
                else
                    abort();
                break;
            case 'b':
                /* printf("option -b with value '%s'\n", optarg); */
                last_boot_file = malloc(strlen(optarg) + 1);
                if (last_boot_file)
                    strcpy(last_boot_file, optarg);
                else
                    abort();
                break;
            case 'n':
                /* printf("option -n with value '%s'\n", optarg); */
                new_boot_file = malloc(strlen(optarg) + 1);
                if (new_boot_file)
                    strcpy(new_boot_file, optarg);
                else
                    abort();
                break;
            case 'f':
                /* printf("option -f with value '%s'\n", optarg); */
                fake_lspci_file = malloc(strlen(optarg) + 1);
                if (fake_lspci_file)
                    strcpy(fake_lspci_file, optarg);
                else
                    abort();
                break;
            case 'm':
                /* printf("option -m with value '%s'\n", optarg); */
                fake_modules_path = malloc(strlen(optarg) + 1);
                if (fake_modules_path)
                    strcpy(fake_modules_path, optarg);
                else
                    abort();
                break;
            case 's':
                /* printf("option -p with value '%s'\n", optarg); */
                gpu_detection_path = malloc(strlen(optarg) + 1);
                if (gpu_detection_path)
                    strcpy(gpu_detection_path, optarg);
                else
                    abort();
                break;
            case 'z':
                /* printf("option -p with value '%s'\n", optarg); */
                prime_settings = strdup(optarg);
                if (!prime_settings)
                    abort();
                break;
            case 'h':
                /* printf("option -p with value '%s'\n", optarg); */
                dmi_product_version_path = strdup(optarg);
                if (!dmi_product_version_path)
                    abort();
                break;
            case 'i':
                /* printf("option -p with value '%s'\n", optarg); */
                dmi_product_name_path = strdup(optarg);
                if (!dmi_product_name_path)
                    abort();
                break;
            case 'j':
                nvidia_driver_version_path = strdup(optarg);
                if (!nvidia_driver_version_path)
                    abort();
                break;
            case 'k':
                modprobe_d_path = strdup(optarg);
                if (!modprobe_d_path)
                    abort();
                break;
            case 'w':
                amdgpu_pro_px_file = strdup(optarg);
                if (!amdgpu_pro_px_file)
                    abort();
                break;
            case '?':
                /* getopt_long already printed an error message. */
                exit(1);
                break;

            default:
                abort();
        }

    }
    /*
    if (dry_run)
        printf("dry-run flag is set\n");
    */

    /* Send messages to the log or to stdout */
    if (log_file) {
        if (backup_log) {
            /* Move the old log away */
            move_log();
        }
        log_handle = fopen(log_file, "w");

        if (!log_handle) {
            /* Use stdout */
            log_handle = stdout;
            fprintf(log_handle, "Warning: writing to %s failed (%s)\n",
                    log_file, strerror(errno));
        }
    }
    else {
        log_handle = stdout;
    }

    if (is_disabled_in_cmdline()) {
        fprintf(log_handle, "Disabled by kernel parameter \"%s\"\n",
                KERN_PARAM);
        goto end;
    }


    /* TODO: require arguments and abort if they're not available */

    if (log_file)
        fprintf(log_handle, "log_file: %s\n", log_file);

    if (!last_boot_file)
        last_boot_file = strdup(LAST_BOOT);

    if (last_boot_file)
        fprintf(log_handle, "last_boot_file: %s\n", last_boot_file);
    else {
        fprintf(log_handle, "No last_boot_file!\n");
        goto end;
    }

    if (!new_boot_file)
        new_boot_file = strdup(last_boot_file);
    fprintf(log_handle, "new_boot_file: %s\n", new_boot_file);

    if (fake_lspci_file)
        fprintf(log_handle, "fake_lspci_file: %s\n", fake_lspci_file);

    if (!gpu_detection_path)
        gpu_detection_path = strdup("/run");

    if (prime_settings)
        fprintf(log_handle, "prime_settings file: %s\n", prime_settings);
    else {
        prime_settings = strdup("/etc/prime-discrete");
        if (!prime_settings) {
            fprintf(log_handle, "Couldn't allocate prime_settings\n");
            goto end;
        }
    }

    if (dmi_product_name_path)
        fprintf(log_handle, "dmi_product_name_path file: %s\n", dmi_product_name_path);
    else {
        dmi_product_name_path = strdup("/sys/class/dmi/id/product_name");
        if (!dmi_product_name_path) {
            fprintf(log_handle, "Couldn't allocate dmi_product_name_path\n");
            goto end;
        }
    }

    if (dmi_product_version_path)
        fprintf(log_handle, "dmi_product_version_path file: %s\n", dmi_product_version_path);
    else {
        dmi_product_version_path = strdup("/sys/class/dmi/id/product_version");
        if (!dmi_product_version_path) {
            fprintf(log_handle, "Couldn't allocate dmi_product_version_path\n");
            goto end;
        }
    }

    if (nvidia_driver_version_path)
        fprintf(log_handle, "nvidia_driver_version_path file: %s\n", nvidia_driver_version_path);
    else {
        nvidia_driver_version_path = strdup("/sys/module/nvidia/version");
        if (!nvidia_driver_version_path) {
            fprintf(log_handle, "Couldn't allocate nvidia_driver_version_path\n");
            goto end;
        }
    }

    if (amdgpu_pro_px_file)
        fprintf(log_handle, "amdgpu_pro_px_file file: %s\n", amdgpu_pro_px_file);
    else {
        amdgpu_pro_px_file = strdup(AMDGPU_PRO_PX);
        if (!amdgpu_pro_px_file) {
            fprintf(log_handle, "Couldn't allocate amdgpu_pro_px_file\n");
            goto end;
        }
    }

    if (modprobe_d_path)
        fprintf(log_handle, "modprobe_d_path file: %s\n", modprobe_d_path);
    else {
        modprobe_d_path = strdup("/etc/modprobe.d");
        if (!modprobe_d_path) {
            fprintf(log_handle, "Couldn't allocate modprobe_d_path\n");
            goto end;
        }
    }

    if (xorg_conf_d_path)
        fprintf(log_handle, "xorg_conf_d_path file: %s\n", xorg_conf_d_path);
    else {
        xorg_conf_d_path = strdup("/usr/share/X11/xorg.conf.d");
        if (!xorg_conf_d_path) {
            fprintf(log_handle, "Couldn't allocate xorg_conf_d_path\n");
            goto end;
        }
    }

    if (fake_modules_path)
        fprintf(log_handle, "fake_modules_path file: %s\n", fake_modules_path);

    nvidia_loaded = is_module_loaded("nvidia");
    nvidia_unloaded = nvidia_loaded ? false : has_unloaded_module("nvidia");
    nvidia_blacklisted = is_module_blacklisted("nvidia");
    intel_loaded = is_module_loaded("i915") || is_module_loaded("i810");
    radeon_loaded = is_module_loaded("radeon");
    radeon_blacklisted = is_module_blacklisted("radeon");
    amdgpu_loaded = is_module_loaded("amdgpu");
    amdgpu_blacklisted = is_module_blacklisted("amdgpu");
    amdgpu_versioned = is_module_versioned("amdgpu");
    amdgpu_pro_px_installed = exists_not_empty(amdgpu_pro_px_file);
    nouveau_loaded = is_module_loaded("nouveau");
    nouveau_blacklisted = is_module_blacklisted("nouveau");


    if (fake_lspci_file) {
        nvidia_kmod_available = fake_module_available;
        amdgpu_kmod_available = fake_module_available;
        amdgpu_versioned = fake_module_versioned ? true : false;
    }
    else {
        nvidia_kmod_available = is_module_available("nvidia");
        amdgpu_kmod_available = is_module_available("amdgpu");
    }

    amdgpu_is_pro = amdgpu_kmod_available && amdgpu_versioned;

    fprintf(log_handle, "Is nvidia loaded? %s\n", (nvidia_loaded ? "yes" : "no"));
    fprintf(log_handle, "Was nvidia unloaded? %s\n", (nvidia_unloaded ? "yes" : "no"));
    fprintf(log_handle, "Is nvidia blacklisted? %s\n", (nvidia_blacklisted ? "yes" : "no"));
    fprintf(log_handle, "Is intel loaded? %s\n", (intel_loaded ? "yes" : "no"));
    fprintf(log_handle, "Is radeon loaded? %s\n", (radeon_loaded ? "yes" : "no"));
    fprintf(log_handle, "Is radeon blacklisted? %s\n", (radeon_blacklisted ? "yes" : "no"));
    fprintf(log_handle, "Is amdgpu loaded? %s\n", (amdgpu_loaded ? "yes" : "no"));
    fprintf(log_handle, "Is amdgpu blacklisted? %s\n", (amdgpu_blacklisted ? "yes" : "no"));
    fprintf(log_handle, "Is amdgpu versioned? %s\n", (amdgpu_versioned ? "yes" : "no"));
    fprintf(log_handle, "Is amdgpu pro stack? %s\n", (amdgpu_is_pro ? "yes" : "no"));
    fprintf(log_handle, "Is nouveau loaded? %s\n", (nouveau_loaded ? "yes" : "no"));
    fprintf(log_handle, "Is nouveau blacklisted? %s\n", (nouveau_blacklisted ? "yes" : "no"));
    fprintf(log_handle, "Is nvidia kernel module available? %s\n", (nvidia_kmod_available ? "yes" : "no"));
    fprintf(log_handle, "Is amdgpu kernel module available? %s\n", (amdgpu_kmod_available ? "yes" : "no"));

    /* Get the driver to use for intel in an optimus system */
    prime_intel_driver = get_prime_intel_driver();

    if (fake_lspci_file) {
        /* Get the current system data from a file */
        status = read_data_from_file(current_devices, &cards_n,
                                     fake_lspci_file);
        if (!status) {
            fprintf(log_handle, "Error: can't read %s\n", fake_lspci_file);
            goto end;
        }
        /* Set data in the devices structs */
        for(i = 0; i < cards_n; i++) {
            if (current_devices[i]->vendor_id == NVIDIA) {
                has_nvidia = true;
            }
            else if (current_devices[i]->vendor_id == AMD) {
                has_amd = true;
            }
            else if (current_devices[i]->vendor_id == INTEL) {
                has_intel = true;
            }
            /* Set unavailable fake outputs */
            current_devices[i]->has_connected_outputs = -1;
        }
        /* Set fake offloading */
        offloading = fake_offloading;
    }
    else {
        /* Get the pci_access structure */
        pacc = pci_alloc();

        if (!pacc) {
            fprintf(log_handle, "Error: failed to acces the PCI library\n");
            goto end;
        }
        /* Initialize the PCI library */
        pci_init(pacc);
        pci_scan_bus(pacc);

        /* Iterate over all devices */
        for (dev=pacc->devices; dev; dev=dev->next) {
             /* Fill in header info we need */
            pci_fill_info(dev, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_CLASS);
            if (PCIINFOCLASSES(dev->device_class)) {
                pm_dev = scan_device(dev);
                if (pm_dev) {
                    fprintf(log_handle, "Vendor/Device Id: %x:%x\n", dev->vendor_id, dev->device_id);
                    fprintf(log_handle, "BusID \"PCI:%d@%d:%d:%d\"\n",
                            (int)dev->bus, (int)dev->domain, (int)dev->dev, (int)dev->func);
                    fprintf(log_handle, "Is boot vga? %s\n", (pci_device_is_boot_vga(dev) ? "yes" : "no"));

                    if (!is_device_bound_to_driver(dev)) {
                        fprintf(log_handle, "The device is not bound to any driver.\n");
                    }

                    if (is_device_pci_passthrough(dev)) {
                        fprintf(log_handle, "The device is a pci passthrough. Skipping...\n");
                        continue;
                    }

                    /* We don't support more than MAX_CARDS_N */
                    if (cards_n < MAX_CARDS_N) {
                        current_devices[cards_n] = malloc(sizeof(struct device));
                        if (!current_devices[cards_n]) {
                            if (pm_dev->config)
                                free(pm_dev->config);
                            if (pm_dev->present)
                                free(pm_dev->present);
                            free(pm_dev);
                            goto end;
                        }
                        current_devices[cards_n]->boot_vga = pci_device_is_boot_vga(dev);
                        current_devices[cards_n]->vendor_id = dev->vendor_id;
                        current_devices[cards_n]->device_id = dev->device_id;
                        current_devices[cards_n]->domain = dev->domain;
                        current_devices[cards_n]->bus = dev->bus;
                        current_devices[cards_n]->dev = dev->dev;
                        current_devices[cards_n]->func = dev->func;

                    if (dev->vendor_id == NVIDIA) {
                        has_nvidia = true;

                        if (!current_devices[cards_n]->boot_vga) {
                            /* Do not enable RTD3 unless it's a laptop */
                            if (is_laptop()) {
                                nvidia_runtimepm_supported = is_nv_runtimepm_supported(dev->device_id);

                                if (!nvidia_runtimepm_supported) {
                                    /* This is a fairly expensive call, so check the database first */
                                    get_d3_substates(pm_dev, &d3cold, &d3hot);
                                    nvidia_runtimepm_supported = d3hot;
                                }
                            }
                            else {
                                nvidia_runtimepm_supported = false;
                            }

                            fprintf(log_handle, "Is nvidia runtime pm supported for \"0x%x\"? %s\n", dev->device_id,
                                    nvidia_runtimepm_supported ? "yes" : "no");

                            if (nvidia_runtimepm_supported)
                                create_runtime_file("nvidia_runtimepm_supported");

                            nvidia_runtimepm_enabled = is_nv_runtimepm_enabled(dev);
                            fprintf(log_handle, "Is nvidia runtime pm enabled for \"0x%x\"? %s\n", dev->device_id,
                                    nvidia_runtimepm_enabled ? "yes" : "no");

                            if (nvidia_runtimepm_enabled)
                                create_runtime_file("nvidia_runtimepm_enabled");
                        }
                    }
                    else if (dev->vendor_id == INTEL) {
                        has_intel = true;
                    }
                    else if (dev->vendor_id == AMD) {
                        has_amd = true;
                    }

                    if (pm_dev->config)
                        free(pm_dev->config);
                    if (pm_dev->present)
                        free(pm_dev->present);
                    free(pm_dev);
                    }
                    else {
                        fprintf(log_handle, "Warning: too many devices %d. "
                                            "Max supported %d. Ignoring the rest.\n",
                                            cards_n, MAX_CARDS_N);
                        free(pm_dev->config);
                        free(pm_dev->present);
                        free(pm_dev);
                        break;
                    }

                    cards_n++;
                }
            }
        }
        /* Close everything */
        pci_cleanup(pacc);
        pacc = NULL;
    }

    /* Probe graphic drivers earlier since some graphic related application
     * (e.g. gdm, mutter) rely on udev rules to apply extra configurations.
     */
    if (has_nvidia && !nvidia_blacklisted && !is_module_loaded("nvidia"))
        load_module("nvidia");

    /* Make sure the udev rules are applied for graphic cards.
     *
     * Also make sure to do this before trying to open /dev/dri/card*
     * because doing so too early may trigger a nvidia bug:
     * https://forums.developer.nvidia.com/t/545-29-06-18-1-flip-event-timeout-error-on-startup-shutdown-and-sometimes-suspend-wayland-unusable/274788
     */
    if (has_nvidia && !nvidia_blacklisted) {
        for (i = 0; i < 500; i++, usleep(20000)) {
            if (is_file(UDEV_NVIDIA_COMPLETED))
                break;
        }
        fprintf(log_handle, "Takes %dms to wait for nvidia udev rules completed.\n", i * 20);
    }

    /* Add information about connected outputs */
    add_connected_outputs_info(current_devices, cards_n);

    if (!fake_lspci_file) {
        /* See if it requires RandR offloading */
        offloading = requires_offloading(current_devices, cards_n);
    }
    fprintf(log_handle, "Does it require offloading? %s\n", (offloading ? "yes" : "no"));

    /* Remove a file that will tell other apps such as
     * nvidia-prime if we need to offload rendering.
     */
    if (!offloading && !dry_run)
        unlink(OFFLOADING_CONF);


    /* Read the data from last boot */
    status = read_data_from_file(old_devices, &last_cards_n,
                                 last_boot_file);
    if (!status) {
        fprintf(log_handle, "Can't read %s\n", last_boot_file);
        goto end;
    }

    fprintf(log_handle, "last cards number = %d\n", last_cards_n);

    /* Write the current data */
    status = write_data_to_file(current_devices,
                                cards_n,
                                new_boot_file);
    if (!status) {
        fprintf(log_handle, "Error: can't write to %s\n", last_boot_file);
        goto end;
    }

    fprintf(log_handle, "Has amd? %s\n", (has_amd ? "yes" : "no"));
    fprintf(log_handle, "Has intel? %s\n", (has_intel ? "yes" : "no"));
    fprintf(log_handle, "Has nvidia? %s\n", (has_nvidia ? "yes" : "no"));
    fprintf(log_handle, "How many cards? %d\n", cards_n);

    /* See if the system has changed */
    has_changed = has_system_changed(old_devices,
                                     current_devices,
                                     last_cards_n,
                                     cards_n);
    fprintf(log_handle, "Has the system changed? %s\n", has_changed ? "Yes" : "No");

    if (has_changed)
        fprintf(log_handle, "System configuration has changed\n");

    if (cards_n == 1) {
        fprintf(log_handle, "Single card detected\n");

        /* Get data about the boot_vga card */
        get_boot_vga(current_devices, cards_n,
                     &boot_vga_vendor_id,
                     &boot_vga_device_id);

        if ((boot_vga_vendor_id == INTEL) || (boot_vga_vendor_id == AMD)) {
            if (offloading && nvidia_unloaded) {
                /* NVIDIA PRIME */
                fprintf(log_handle, "PRIME detected\n");

                /* Get the details of the disabled discrete from a file */
                find_disabled_cards(gpu_detection_path, current_devices,
                                    &cards_n, add_gpu_from_file);

                /* Get data about the first discrete card */
                get_first_discrete(current_devices, cards_n,
                                   &discrete_device);

                /* Try to enable prime */
                if (enable_prime(prime_settings,
                                 &discrete_device, current_devices, cards_n)) {

                    /* Write permanent settings about offloading */
                    set_offloading();
                }
                goto end;
            }
            else if (has_changed && amdgpu_loaded && amdgpu_is_pro && amdgpu_pro_px_installed) {
                /* If amdgpu-pro-px exists, we can assume it's a pxpress system. But now the
                 * system has one card only, user probably disabled Switchable Graphics in
                 * BIOS. So we need to use discrete config file here.
                 */
                fprintf(log_handle, "AMDGPU-Pro discrete graphics detected\n");

                run_amdgpu_pro_px(RESET);
            }
            else {
                fprintf(log_handle, "Nothing to do\n");
            }
        }
        else if (boot_vga_vendor_id == NVIDIA) {
            if (remove_offload_serverlayout() == -ENOENT) {
                fprintf(log_handle, "Nothing to do\n");
            }
        }
    }
    else if (cards_n > 1) {
        /* Get data about the boot_vga card */
        get_boot_vga(current_devices, cards_n,
                     &boot_vga_vendor_id,
                     &boot_vga_device_id);

        /* Get data about the first discrete card */
        get_first_discrete(current_devices, cards_n,
                           &discrete_device);

        /* Intel or AMD + another GPU */
        if ((boot_vga_vendor_id == INTEL) || (boot_vga_vendor_id == AMD)) {
            fprintf(log_handle, "%s IGP detected\n", (boot_vga_vendor_id == INTEL) ? "Intel" : "AMD");
            /* AMDGPU-Pro Switchable */
            if (has_changed && amdgpu_loaded && amdgpu_is_pro && amdgpu_pro_px_installed) {
                /* Similar to switchable enabled -> disabled case, but this time
                 * to deal with switchable disabled -> enabled change.
                 */
                fprintf(log_handle, "AMDGPU-Pro switchable graphics detected\n");

                run_amdgpu_pro_px(MODE_POWERSAVING);
            }
            /* NVIDIA Optimus */
            else if ((intel_loaded || amdgpu_loaded) && !nouveau_loaded &&
                                 (nvidia_loaded || nvidia_kmod_available)) {
                fprintf(log_handle, "NVIDIA hybrid system\n");

                /* Try to enable prime */
                if (enable_prime(prime_settings,
                             &discrete_device, current_devices, cards_n)) {

                    /* Write permanent settings about offloading */
                    set_offloading();
                }
                else {
                    fprintf(log_handle, "Nothing to do\n");
                }

                goto end;
            }
            else {
                /* Desktop system or Laptop with open drivers only */
                fprintf(log_handle, "Desktop system detected\n");
                fprintf(log_handle, "or laptop with open drivers\n");
                fprintf(log_handle, "Nothing to do\n");
            }
        }
        else {
                fprintf(log_handle, "Unsupported discrete card vendor: %x\n", discrete_device.vendor_id);
                fprintf(log_handle, "Nothing to do\n");
        }
    }




end:
    if (pacc)
        pci_cleanup(pacc);

    if (log_file)
        free(log_file);

    if (last_boot_file)
        free(last_boot_file);

    if (new_boot_file)
        free(new_boot_file);

    if (fake_lspci_file)
        free(fake_lspci_file);

    if (gpu_detection_path)
        free(gpu_detection_path);

    if (fake_modules_path)
        free(fake_modules_path);

    if (prime_settings)
        free(prime_settings);

    if (dmi_product_name_path)
        free(dmi_product_name_path);

    if (dmi_product_version_path)
        free(dmi_product_version_path);

    if (amdgpu_pro_px_file)
        free(amdgpu_pro_px_file);

    if (nvidia_driver_version_path)
        free(nvidia_driver_version_path);

    if (modprobe_d_path)
        free(modprobe_d_path);

    if (xorg_conf_d_path)
        free(xorg_conf_d_path);

    /* Free the devices structs */
    for(i = 0; i < cards_n; i++) {
        free(current_devices[i]);
    }

    for(i = 0; i < last_cards_n; i++) {
        free(old_devices[i]);
    }

    /* Flush and close the log */
    if (log_handle != stdout) {
        fflush(log_handle);
        fclose(log_handle);
    }

    return 0;
}
