path: root/src/udev/udevadm-info.c

/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (C) 2004-2009 Kay Sievers <kay@vrfy.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#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 "dirent-util.h"
#include "fd-util.h"
#include "string-util.h"
#include "udev-util.h"
#include "udev.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 int i;

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

static void print_all_attributes(struct udev_device *device, const char *key) {
        struct udev_list_entry *sysattr;

        udev_list_entry_foreach(sysattr, udev_device_get_sysattr_list_entry(device)) {
                const char *name;
                const char *value;
                size_t len;

                name = udev_list_entry_get_name(sysattr);
                if (skip_attribute(name))
                        continue;

                value = udev_device_get_sysattr_value(device, name);
                if (value == NULL)
                        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(struct udev_device *device) {
        struct udev_device *device_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");

        printf("  looking at device '%s':\n", udev_device_get_devpath(device));
        printf("    KERNEL==\"%s\"\n", udev_device_get_sysname(device));
        str = udev_device_get_subsystem(device);
        if (str == NULL)
                str = "";
        printf("    SUBSYSTEM==\"%s\"\n", str);
        str = udev_device_get_driver(device);
        if (str == NULL)
                str = "";
        printf("    DRIVER==\"%s\"\n", str);
        print_all_attributes(device, "ATTR");

        device_parent = device;
        do {
                device_parent = udev_device_get_parent(device_parent);
                if (device_parent == NULL)
                        break;
                printf("  looking at parent device '%s':\n", udev_device_get_devpath(device_parent));
                printf("    KERNELS==\"%s\"\n", udev_device_get_sysname(device_parent));
                str = udev_device_get_subsystem(device_parent);
                if (str == NULL)
                        str = "";
                printf("    SUBSYSTEMS==\"%s\"\n", str);
                str = udev_device_get_driver(device_parent);
                if (str == NULL)
                        str = "";
                printf("    DRIVERS==\"%s\"\n", str);
                print_all_attributes(device_parent, "ATTRS");
        } while (device_parent != NULL);

        return 0;
}

static void print_record(struct udev_device *device) {
        const char *str;
        int i;
        struct udev_list_entry *list_entry;

        printf("P: %s\n", udev_device_get_devpath(device));

        str = udev_device_get_devnode(device);
        if (str != NULL)
                printf("N: %s\n", str + STRLEN("/dev/"));

        i = udev_device_get_devlink_priority(device);
        if (i != 0)
                printf("L: %i\n", i);

        udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(device))
                printf("S: %s\n",
                       udev_list_entry_get_name(list_entry) + STRLEN("/dev/"));

        udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(device))
                printf("E: %s=%s\n",
                       udev_list_entry_get_name(list_entry),
                       udev_list_entry_get_value(list_entry));
        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 == NULL)
                        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(struct udev *udev) {
        _cleanup_udev_enumerate_unref_ struct udev_enumerate *udev_enumerate;
        struct udev_list_entry *list_entry;

        udev_enumerate = udev_enumerate_new(udev);
        if (udev_enumerate == NULL)
                return -ENOMEM;

        udev_enumerate_scan_devices(udev_enumerate);
        udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
                _cleanup_udev_device_unref_ struct udev_device *device;

                device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
                if (device != NULL)
                        print_record(device);
        }

        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;

                        dir2 = fdopendir(openat(dirfd(dir), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
                        if (dir2 != NULL)
                                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(struct udev *udev) {
        _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 != NULL)
                cleanup_dir(dir1, S_ISVTX, 1);

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

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

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

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

static void 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);
}

static int uinfo(struct udev *udev, int argc, char *argv[]) {
        _cleanup_udev_device_unref_ struct udev_device *device = NULL;
        bool root = 0;
        bool export = 0;
        const char *export_prefix = NULL;
        char name[UTIL_PATH_SIZE];
        struct udev_list_entry *list_entry;
        int c;

        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 != NULL) {
                                fprintf(stderr, "device already specified\n");
                                return 2;
                        }

                        device = find_device(udev, optarg, "/dev/");
                        if (device == NULL) {
                                fprintf(stderr, "device node not found\n");
                                return 2;
                        }
                        break;
                }
                case 'p':
                        if (device != NULL) {
                                fprintf(stderr, "device already specified\n");
                                return 2;
                        }

                        device = find_device(udev, optarg, "/sys");
                        if (device == NULL) {
                                fprintf(stderr, "syspath not found\n");
                                return 2;
                        }
                        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 {
                                fprintf(stderr, "unknown query type\n");
                                return 3;
                        }
                        break;
                case 'r':
                        root = true;
                        break;
                case 'd':
                        action = ACTION_DEVICE_ID_FILE;
                        strscpy(name, sizeof(name), optarg);
                        break;
                case 'a':
                        action = ACTION_ATTRIBUTE_WALK;
                        break;
                case 'e':
                        if (export_devices(udev) < 0)
                                return 1;
                        return 0;
                case 'c':
                        cleanup_db(udev);
                        return 0;
                case 'x':
                        export = true;
                        break;
                case 'P':
                        export_prefix = optarg;
                        break;
                case 'V':
                        print_version();
                        return 0;
                case 'h':
                        help();
                        return 0;
                default:
                        return 1;
                }

        switch (action) {
        case ACTION_QUERY:
                if (!device) {
                        if (!argv[optind]) {
                                help();
                                return 2;
                        }
                        device = find_device(udev, argv[optind], NULL);
                        if (!device) {
                                fprintf(stderr, "Unknown device, --name=, --path=, or absolute path in /dev/ or /sys expected.\n");
                                return 4;
                        }
                }

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

                        if (node == NULL) {
                                fprintf(stderr, "no device node found\n");
                                return 5;
                        }

                        if (root)
                                printf("%s\n", udev_device_get_devnode(device));
                        else
                                printf("%s\n",
                                       udev_device_get_devnode(device) + STRLEN("/dev/"));
                        break;
                }
                case QUERY_SYMLINK:
                        list_entry = udev_device_get_devlinks_list_entry(device);
                        while (list_entry != NULL) {
                                if (root)
                                        printf("%s", udev_list_entry_get_name(list_entry));
                                else
                                        printf("%s",
                                               udev_list_entry_get_name(list_entry) + STRLEN("/dev/"));
                                list_entry = udev_list_entry_get_next(list_entry);
                                if (list_entry != NULL)
                                        printf(" ");
                        }
                        printf("\n");
                        break;
                case QUERY_PATH:
                        printf("%s\n", udev_device_get_devpath(device));
                        return 0;
                case QUERY_PROPERTY:
                        list_entry = udev_device_get_properties_list_entry(device);
                        while (list_entry != NULL) {
                                if (export)
                                        printf("%s%s='%s'\n", strempty(export_prefix),
                                               udev_list_entry_get_name(list_entry),
                                               udev_list_entry_get_value(list_entry));
                                else
                                        printf("%s=%s\n", udev_list_entry_get_name(list_entry), udev_list_entry_get_value(list_entry));

                                list_entry = udev_list_entry_get_next(list_entry);
                        }
                        break;
                case QUERY_ALL:
                        print_record(device);
                        break;
                default:
                        assert_not_reached("unknown query type");
                }
                break;
        case ACTION_ATTRIBUTE_WALK:
                if (!device && argv[optind]) {
                        device = find_device(udev, argv[optind], NULL);
                        if (!device) {
                                fprintf(stderr, "Unknown device, absolute path in /dev/ or /sys expected.\n");
                                return 4;
                        }
                }
                if (!device) {
                        fprintf(stderr, "Unknown device, --name=, --path=, or absolute path in /dev/ or /sys expected.\n");
                        return 4;
                }
                print_device_chain(device);
                break;
        case ACTION_DEVICE_ID_FILE:
                if (stat_device(name, export, export_prefix) != 0)
                        return 1;
                break;
        }

        return 0;
}

const struct udevadm_cmd udevadm_info = {
        .name = "info",
        .cmd = uinfo,
        .help = "Query sysfs or the udev database",
};