/*

 * kmod-static-nodes - manage modules.devname

 *

 * Copyright (C) 2004-2012 Kay Sievers <kay@vrfy.org>

 * Copyright (C) 2011-2013  ProFUSION embedded systems

 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>

 *

 * 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 <errno.h>

#include <getopt.h>

#include <limits.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/utsname.h>

#include <shared/util.h>

#include "kmod.h"

struct static_nodes_format {

	const char *name;

	int (*write)(FILE *, char[], char[], char, unsigned int, unsigned int);

	const char *description;

};

static const struct static_nodes_format static_nodes_format_human;

static const struct static_nodes_format static_nodes_format_tmpfiles;

static const struct static_nodes_format static_nodes_format_devname;

static const struct static_nodes_format *static_nodes_formats[] = {

	&static_nodes_format_human,

	&static_nodes_format_tmpfiles,

	&static_nodes_format_devname,

};

static const char cmdopts_s[] = "o:f:h";

static const struct option cmdopts[] = {

	{ "output", required_argument, 0, 'o'},

	{ "format", required_argument, 0, 'f'},

	{ "help", no_argument, 0, 'h'},

	{ },

};

static int write_human(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)

{

	int ret;

	ret = fprintf(out,

			"Module: %s\n"

			"\tDevice node: /dev/%s\n"

			"\t\tType: %s device\n"

			"\t\tMajor: %u\n"

			"\t\tMinor: %u\n",

			modname, devname,

			(type == 'c') ? "character" : "block", maj, min);

	if (ret >= 0)

		return EXIT_SUCCESS;

	else

		return EXIT_FAILURE;

}

static const struct static_nodes_format static_nodes_format_human = {

	.name = "human",

	.write = write_human,

	.description = "(default) a human readable format. Do not parse.",

};

static int write_tmpfiles(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)

{

	const char *dir;

	int ret;

	dir = strrchr(devname, '/');

	if (dir) {

		ret = fprintf(out, "d /dev/%.*s 0755 - - -\n",

			      (int)(dir - devname), devname);

		if (ret < 0)

			return EXIT_FAILURE;

	}

	ret = fprintf(out, "%c! /dev/%s 0600 - - - %u:%u\n",

		      type, devname, maj, min);

	if (ret < 0)

		return EXIT_FAILURE;

	return EXIT_SUCCESS;

}

static const struct static_nodes_format static_nodes_format_tmpfiles = {

	.name = "tmpfiles",

	.write = write_tmpfiles,

	.description = "the tmpfiles.d(5) format used by systemd-tmpfiles.",

};

static int write_devname(FILE *out, char modname[], char devname[], char type, unsigned int maj, unsigned int min)

{

	int ret;

	ret = fprintf(out, "%s %s %c%u:%u\n", modname, devname, type, maj, min);

	if (ret >= 0)

		return EXIT_SUCCESS;

	else

		return EXIT_FAILURE;

}

static const struct static_nodes_format static_nodes_format_devname = {

	.name = "devname",

	.write = write_devname,

	.description = "the modules.devname format.",

};

static void help(void)

{

	size_t i;

	printf("Usage:\n"

	       "\t%s static-nodes [options]\n"

	       "\n"

	       "kmod static-nodes outputs the static-node information of the currently running kernel.\n"

	       "\n"

	       "Options:\n"

	       "\t-f, --format=FORMAT  choose format to use: see \"Formats\"\n"

	       "\t-o, --output=FILE    write output to file\n"

	       "\t-h, --help           show this help\n"

	       "\n"

	       "Formats:\n",

	 program_invocation_short_name);

	for (i = 0; i < ARRAY_SIZE(static_nodes_formats); i++) {

		if (static_nodes_formats[i]->description != NULL) {

			printf("\t%-12s %s\n", static_nodes_formats[i]->name,

			       static_nodes_formats[i]->description);

		}

	}

}

static int do_static_nodes(int argc, char *argv[])

{

	struct utsname kernel;

	char modules[PATH_MAX], buf[4096];

	const char *output = "/dev/stdout";

	FILE *in = NULL, *out = NULL;

	const struct static_nodes_format *format = &static_nodes_format_human;

	int r, ret = EXIT_SUCCESS;

	for (;;) {

		int c, idx = 0, valid;

		size_t i;

		c = getopt_long(argc, argv, cmdopts_s, cmdopts, &idx);

		if (c == -1) {

			break;

		}

		switch (c) {

		case 'o':

			output = optarg;

			break;

		case 'f':

			valid = 0;

			for (i = 0; i < ARRAY_SIZE(static_nodes_formats); i++) {

				if (streq(static_nodes_formats[i]->name, optarg)) {

					format = static_nodes_formats[i];

					valid = 1;

				}

			}

			if (!valid) {

				fprintf(stderr, "Unknown format: '%s'.\n",

					optarg);

				help();

				ret = EXIT_FAILURE;

				goto finish;

			}

			break;

		case 'h':

			help();

			goto finish;

		case '?':

			ret = EXIT_FAILURE;

			goto finish;

		default:

			fprintf(stderr, "Unexpected commandline option '%c'.\n",

				c);

			help();

			ret = EXIT_FAILURE;

			goto finish;

		}

	}

	if (uname(&kernel) < 0) {

		fputs("Error: uname failed!\n", stderr);

		ret = EXIT_FAILURE;

		goto finish;

	}

	snprintf(modules, sizeof(modules), "/lib/modules/%s/modules.devname", kernel.release);

	in = fopen(modules, "re");

	if (in == NULL) {

		if (errno == ENOENT) {

			fprintf(stderr, "Warning: /lib/modules/%s/modules.devname not found - ignoring\n",

				kernel.release);

			ret = EXIT_SUCCESS;

		} else {

			fprintf(stderr, "Error: could not open /lib/modules/%s/modules.devname - %m\n",

				kernel.release);

			ret = EXIT_FAILURE;

		}

		goto finish;

	}

	r = mkdir_parents(output, 0755);

	if (r < 0) {

		fprintf(stderr, "Error: could not create parent directory for %s - %m.\n", output);

		ret = EXIT_FAILURE;

		goto finish;

	}

	out = fopen(output, "we");

	if (out == NULL) {

		fprintf(stderr, "Error: could not create %s - %m\n", output);

		ret = EXIT_FAILURE;

		goto finish;

	}

	while (fgets(buf, sizeof(buf), in) != NULL) {

		char modname[PATH_MAX];

		char devname[PATH_MAX];

		char type;

		unsigned int maj, min;

		int matches;

		if (buf[0] == '#')

			continue;

		matches = sscanf(buf, "%s %s %c%u:%u", modname, devname,

				 &type, &maj, &min);

		if (matches != 5 || (type != 'c' && type != 'b')) {

			fprintf(stderr, "Error: invalid devname entry: %s", buf);

			ret = EXIT_FAILURE;

			continue;

		}

		format->write(out, modname, devname, type, maj, min);

	}

finish:

	if (in)

		fclose(in);

	if (out)

		fclose(out);

	return ret;

}

const struct kmod_cmd kmod_cmd_static_nodes = {

	.name = "static-nodes",

	.cmd = do_static_nodes,

	.help = "outputs the static-node information installed with the currently running kernel",

};