/* SPDX-License-Identifier: GPL-2.0+ */

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#include "sd-device.h"

#include "alloc-util.h"
#include "device-enumerator-private.h"
#include "device-private.h"
#include "device-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "string-util.h"
#include "udevadm.h"
#include "udevadm-util.h"

static bool skip_attribute(const char *name) {
        static const char* const skip[] = {
                "uevent",
                "dev",
                "modalias",
                "resource",
                "driver",
                "subsystem",
                "module",
        };
        unsigned i;

        for (i = 0; i < ELEMENTSOF(skip); i++)
                if (streq(name, skip[i]))
                        return true;
        return false;
}

static void print_all_attributes(sd_device *device, const char *key) {
        const char *name, *value;

        FOREACH_DEVICE_PROPERTY(device, name, value) {
                size_t len;

                if (skip_attribute(name))
                        continue;

                /* skip any values that look like a path */
                if (value[0] == '/')
                        continue;

                /* skip nonprintable attributes */
                len = strlen(value);
                while (len > 0 && isprint(value[len-1]))
                        len--;
                if (len > 0)
                        continue;

                printf("    %s{%s}==\"%s\"\n", key, name, value);
        }
        printf("\n");
}

static int print_device_chain(sd_device *device) {
        sd_device *child, *parent;
        const char *str;

        printf("\n"
               "Udevadm info starts with the device specified by the devpath and then\n"
               "walks up the chain of parent devices. It prints for every device\n"
               "found, all possible attributes in the udev rules key format.\n"
               "A rule to match, can be composed by the attributes of the device\n"
               "and the attributes from one single parent device.\n"
               "\n");

        (void) sd_device_get_devpath(device, &str);
        printf("  looking at device '%s':\n", str);
        (void) sd_device_get_sysname(device, &str);
        printf("    KERNEL==\"%s\"\n", str);
        if (sd_device_get_subsystem(device, &str) < 0)
                str = "";
        printf("    SUBSYSTEM==\"%s\"\n", str);
        if (sd_device_get_driver(device, &str) < 0)
                str = "";
        printf("    DRIVER==\"%s\"\n", str);
        print_all_attributes(device, "ATTR");

        for (child = device; sd_device_get_parent(child, &parent) >= 0; child = parent) {
                (void) sd_device_get_devpath(parent, &str);
                printf("  looking at parent device '%s':\n", str);
                (void) sd_device_get_sysname(parent, &str);
                printf("    KERNELS==\"%s\"\n", str);
                if (sd_device_get_subsystem(parent, &str) < 0)
                        str = "";
                printf("    SUBSYSTEMS==\"%s\"\n", str);
                if (sd_device_get_driver(parent, &str) < 0)
                        str = "";
                printf("    DRIVERS==\"%s\"\n", str);
                print_all_attributes(parent, "ATTRS");
        }

        return 0;
}

static void print_record(sd_device *device) {
        const char *str, *val;
        int i;

        (void) sd_device_get_devpath(device, &str);
        printf("P: %s\n", str);

        if (sd_device_get_devname(device, &str) >= 0)
                printf("N: %s\n", str + STRLEN("/dev/"));

        if (device_get_devlink_priority(device, &i) >= 0)
                printf("L: %i\n", i);

        FOREACH_DEVICE_DEVLINK(device, str)
                printf("S: %s\n", str + STRLEN("/dev/"));

        FOREACH_DEVICE_PROPERTY(device, str, val)
                printf("E: %s=%s\n", str, val);

        printf("\n");
}

static int stat_device(const char *name, bool export, const char *prefix) {
        struct stat statbuf;

        if (stat(name, &statbuf) != 0)
                return -errno;

        if (export) {
                if (!prefix)
                        prefix = "INFO_";
                printf("%sMAJOR=%u\n"
                       "%sMINOR=%u\n",
                       prefix, major(statbuf.st_dev),
                       prefix, minor(statbuf.st_dev));
        } else
                printf("%u:%u\n", major(statbuf.st_dev), minor(statbuf.st_dev));
        return 0;
}

static int export_devices(void) {
        _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
        sd_device *d;
        int r;

        r = sd_device_enumerator_new(&e);
        if (r < 0)
                return r;

        r = sd_device_enumerator_allow_uninitialized(e);
        if (r < 0)
                return r;

        r = device_enumerator_scan_devices(e);
        if (r < 0)
                return r;

        FOREACH_DEVICE_AND_SUBSYSTEM(e, d)
                print_record(d);

        return 0;
}

static void cleanup_dir(DIR *dir, mode_t mask, int depth) {
        struct dirent *dent;

        if (depth <= 0)
                return;

        FOREACH_DIRENT_ALL(dent, dir, break) {
                struct stat stats;

                if (dent->d_name[0] == '.')
                        continue;
                if (fstatat(dirfd(dir), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
                        continue;
                if ((stats.st_mode & mask) != 0)
                        continue;
                if (S_ISDIR(stats.st_mode)) {
                        _cleanup_closedir_ DIR *dir2 = NULL;

                        dir2 = fdopendir(openat(dirfd(dir), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
                        if (dir2)
                                cleanup_dir(dir2, mask, depth-1);

                        (void) unlinkat(dirfd(dir), dent->d_name, AT_REMOVEDIR);
                } else
                        (void) unlinkat(dirfd(dir), dent->d_name, 0);
        }
}

static void cleanup_db(void) {
        _cleanup_closedir_ DIR *dir1 = NULL, *dir2 = NULL, *dir3 = NULL, *dir4 = NULL, *dir5 = NULL;

        (void) unlink("/run/udev/queue.bin");

        dir1 = opendir("/run/udev/data");
        if (dir1)
                cleanup_dir(dir1, S_ISVTX, 1);

        dir2 = opendir("/run/udev/links");
        if (dir2)
                cleanup_dir(dir2, 0, 2);

        dir3 = opendir("/run/udev/tags");
        if (dir3)
                cleanup_dir(dir3, 0, 2);

        dir4 = opendir("/run/udev/static_node-tags");
        if (dir4)
                cleanup_dir(dir4, 0, 2);

        dir5 = opendir("/run/udev/watch");
        if (dir5)
                cleanup_dir(dir5, 0, 1);
}

static int help(void) {

        printf("%s info [OPTIONS] [DEVPATH|FILE]\n\n"
               "Query sysfs or the udev database.\n\n"
               "  -h --help                   Print this message\n"
               "  -V --version                Print version of the program\n"
               "  -q --query=TYPE             Query device information:\n"
               "       name                     Name of device node\n"
               "       symlink                  Pointing to node\n"
               "       path                     sysfs device path\n"
               "       property                 The device properties\n"
               "       all                      All values\n"
               "  -p --path=SYSPATH           sysfs device path used for query or attribute walk\n"
               "  -n --name=NAME              Node or symlink name used for query or attribute walk\n"
               "  -r --root                   Prepend dev directory to path names\n"
               "  -a --attribute-walk         Print all key matches walking along the chain\n"
               "                              of parent devices\n"
               "  -d --device-id-of-file=FILE Print major:minor of device containing this file\n"
               "  -x --export                 Export key/value pairs\n"
               "  -P --export-prefix          Export the key name with a prefix\n"
               "  -e --export-db              Export the content of the udev database\n"
               "  -c --cleanup-db             Clean up the udev database\n"
               , program_invocation_short_name);

        return 0;
}

int info_main(int argc, char *argv[], void *userdata) {
        _cleanup_(sd_device_unrefp) sd_device *device = NULL;
        bool root = false, export = false;
        _cleanup_free_ char *name = NULL;
        const char *export_prefix = NULL;
        int c, r;

        static const struct option options[] = {
                { "name",              required_argument, NULL, 'n' },
                { "path",              required_argument, NULL, 'p' },
                { "query",             required_argument, NULL, 'q' },
                { "attribute-walk",    no_argument,       NULL, 'a' },
                { "cleanup-db",        no_argument,       NULL, 'c' },
                { "export-db",         no_argument,       NULL, 'e' },
                { "root",              no_argument,       NULL, 'r' },
                { "device-id-of-file", required_argument, NULL, 'd' },
                { "export",            no_argument,       NULL, 'x' },
                { "export-prefix",     required_argument, NULL, 'P' },
                { "version",           no_argument,       NULL, 'V' },
                { "help",              no_argument,       NULL, 'h' },
                {}
        };

        enum action_type {
                ACTION_QUERY,
                ACTION_ATTRIBUTE_WALK,
                ACTION_DEVICE_ID_FILE,
        } action = ACTION_QUERY;

        enum query_type {
                QUERY_NAME,
                QUERY_PATH,
                QUERY_SYMLINK,
                QUERY_PROPERTY,
                QUERY_ALL,
        } query = QUERY_ALL;

        while ((c = getopt_long(argc, argv, "aced:n:p:q:rxP:RVh", options, NULL)) >= 0)
                switch (c) {
                case 'n':
                        if (device) {
                                log_error("device already specified");
                                return -EINVAL;
                        }

                        r = find_device(optarg, "/dev/", &device);
                        if (r < 0)
                                return log_error_errno(r, "device node not found: %m");
                        break;
                case 'p':
                        if (device) {
                                log_error("device already specified");
                                return -EINVAL;
                        }

                        r = find_device(optarg, "/sys", &device);
                        if (r < 0)
                                return log_error_errno(r, "syspath not found: %m");
                        break;
                case 'q':
                        action = ACTION_QUERY;
                        if (streq(optarg, "property") || streq(optarg, "env"))
                                query = QUERY_PROPERTY;
                        else if (streq(optarg, "name"))
                                query = QUERY_NAME;
                        else if (streq(optarg, "symlink"))
                                query = QUERY_SYMLINK;
                        else if (streq(optarg, "path"))
                                query = QUERY_PATH;
                        else if (streq(optarg, "all"))
                                query = QUERY_ALL;
                        else {
                                log_error("unknown query type");
                                return -EINVAL;
                        }
                        break;
                case 'r':
                        root = true;
                        break;
                case 'd':
                        action = ACTION_DEVICE_ID_FILE;
                        r = free_and_strdup(&name, optarg);
                        if (r < 0)
                                return log_oom();
                        break;
                case 'a':
                        action = ACTION_ATTRIBUTE_WALK;
                        break;
                case 'e':
                        return export_devices();
                case 'c':
                        cleanup_db();
                        return 0;
                case 'x':
                        export = true;
                        break;
                case 'P':
                        export_prefix = optarg;
                        break;
                case 'V':
                        return print_version();
                case 'h':
                        return help();
                case '?':
                        return -EINVAL;
                default:
                        assert_not_reached("Unknown option");
                }

        switch (action) {
        case ACTION_QUERY:
                if (!device) {
                        if (!argv[optind]) {
                                help();
                                return -EINVAL;
                        }
                        r = find_device(argv[optind], NULL, &device);
                        if (r < 0)
                                return log_error_errno(r, "Unknown device, --name=, --path=, or absolute path in /dev/ or /sys expected: %m");
                }

                switch(query) {
                case QUERY_NAME: {
                        const char *node;

                        r = sd_device_get_devname(device, &node);
                        if (r < 0)
                                return log_error_errno(r, "no device node found: %m");

                        if (root)
                                printf("%s\n", node);
                        else
                                printf("%s\n", node + STRLEN("/dev/"));
                        break;
                }
                case QUERY_SYMLINK: {
                        const char *devlink;
                        bool first = true;

                        FOREACH_DEVICE_DEVLINK(device, devlink) {
                                if (!first)
                                        printf(" ");
                                if (root)
                                        printf("%s", devlink);
                                else
                                        printf("%s", devlink + STRLEN("/dev/"));

                                first = false;
                        }
                        printf("\n");
                        break;
                }
                case QUERY_PATH: {
                        const char *devpath;

                        r = sd_device_get_devpath(device, &devpath);
                        if (r < 0)
                                return log_error_errno(r, "Failed to get device path: %m");

                        printf("%s\n", devpath);
                        return 0;
                }
                case QUERY_PROPERTY: {
                        const char *key, *value;

                        FOREACH_DEVICE_PROPERTY(device, key, value)
                                if (export)
                                        printf("%s%s='%s'\n", strempty(export_prefix), key, value);
                                else
                                        printf("%s=%s\n", key, value);

                        break;
                }
                case QUERY_ALL:
                        print_record(device);
                        break;
                default:
                        assert_not_reached("unknown query type");
                }
                break;
        case ACTION_ATTRIBUTE_WALK:
                if (!device && argv[optind]) {
                        r = find_device(argv[optind], NULL, &device);
                        if (r < 0)
                                return log_error_errno(r, "Unknown device, absolute path in /dev/ or /sys expected: %m");
                }
                if (!device) {
                        log_error("Unknown device, --name=, --path=, or absolute path in /dev/ or /sys expected.");
                        return -EINVAL;
                }
                print_device_chain(device);
                break;
        case ACTION_DEVICE_ID_FILE:
                r = stat_device(name, export, export_prefix);
                if (r < 0)
                        return r;
                break;
        }

        return 0;
}