procps/sysctl.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * Sysctl 1.01 - A utility to read and manipulate the sysctl parameters
  *
  * Copyright 1999 George Staikos
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  *
  * Changelog:
  *	v1.01:
  *		- added -p <preload> to preload values from a file
  *	v1.01.1
  *		- busybox applet aware by <solar@gentoo.org>
  *
  */

 #include "libbb.h"

 /*
  *    Function Prototypes
  */
 static int sysctl_read_setting(const char *setting, int output);
 static int sysctl_write_setting(const char *setting, int output);
 static int sysctl_preload_file(const char *filename, int output);
 static int sysctl_display_all(const char *path, int output, int show_table);

 /*
  *    Globals...
  */
 static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf";
 static const char PROC_SYS[] ALIGN1 = "/proc/sys/";
 enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 };

 /* error messages */
 static const char ERR_UNKNOWN_PARAMETER[] ALIGN1 =
 	"error: unknown parameter '%s'";
 static const char ERR_MALFORMED_SETTING[] ALIGN1 =
 	"error: malformed setting '%s'";
 static const char ERR_NO_EQUALS[] ALIGN1 =
 	"error: '%s' must be of the form name=value";
 static const char ERR_INVALID_KEY[] ALIGN1 =
 	"error: '%s' is an unknown key";
 static const char ERR_UNKNOWN_WRITING[] ALIGN1 =
 	"error setting key '%s'";
 static const char ERR_UNKNOWN_READING[] ALIGN1 =
 	"error reading key '%s'";
 static const char ERR_PERMISSION_DENIED[] ALIGN1 =
 	"error: permission denied on key '%s'";
 static const char ERR_PRELOAD_FILE[] ALIGN1 =
 	"error: cannot open preload file '%s'";
 static const char WARN_BAD_LINE[] ALIGN1 =
 	"warning: %s(%d): invalid syntax, continuing";


 static void dwrite_str(int fd, const char *buf)
 {
 	write(fd, buf, strlen(buf));
 }

 /*
  *    sysctl_main()...
  */
 int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int sysctl_main(int argc, char **argv)
 {
 	int retval = 0;
 	int output = 1;
 	int write_mode = 0;
 	int switches_allowed = 1;

 	if (argc < 2)
 		bb_show_usage();

 	argv++;

 	for (; *argv /*&& **argv*/; argv++) {
 		if (switches_allowed && **argv == '-') {	/* we have a switch */
 			switch ((*argv)[1]) {
 			case 'n':
 				output = 0;
 				break;
 			case 'w':
 				write_mode = 1;
 				switches_allowed = 0;
 				break;
 			case 'p':
 				argv++;
 				return sysctl_preload_file(((*argv /*&& **argv*/) ? *argv : ETC_SYSCTL_CONF),
 							output);
 			case 'a':
 			case 'A':
 				return sysctl_display_all(PROC_SYS, output,
 							((*argv)[1] == 'A'));
 			default:
 				bb_error_msg(ERR_UNKNOWN_PARAMETER, *argv);
 				/* fall through */
 			//case 'h':
 			//case '?':
 				bb_show_usage();
 			}
 		} else {
 			switches_allowed = 0;
 			if (write_mode)
 				retval |= sysctl_write_setting(*argv, output);
 			else
 				sysctl_read_setting(*argv, output);
 		}
 	}
 	return retval;
 } /* end sysctl_main() */

 /*
  * sysctl_preload_file
  * preload the sysctl's from a conf file
  * - we parse the file and then reform it (strip out whitespace)
  */
 #define PRELOAD_BUF 256

 static int sysctl_preload_file(const char *filename, int output)
 {
 	int lineno;
 	char oneline[PRELOAD_BUF];
 	char buffer[PRELOAD_BUF];
 	char *name, *value;
 	FILE *fp;

 	fp = fopen(filename, "r");
 	if (fp == NULL) {
 		bb_error_msg_and_die(ERR_PRELOAD_FILE, filename);
 	}

 	lineno = 0;
 	while (fgets(oneline, sizeof(oneline) - 1, fp)) {
 		lineno++;
 		trim(oneline);
 		if (oneline[0] == '#' || oneline[0] == ';')
 			continue;
 		if (!oneline[0] || !oneline[1])
 			continue;

 		name = strtok(oneline, "=");
 		if (!name) {
 			bb_error_msg(WARN_BAD_LINE, filename, lineno);
 			continue;
 		}
 		trim(name);
 		if (!*name) {
 			bb_error_msg(WARN_BAD_LINE, filename, lineno);
 			continue;
 		}

 		value = strtok(NULL, "\n\r");
 		if (!value) {
 			bb_error_msg(WARN_BAD_LINE, filename, lineno);
 			continue;
 		}
 		while (*value == ' ' || *value == '\t')
 			value++;
 		if (!*value) {
 			bb_error_msg(WARN_BAD_LINE, filename, lineno);
 			continue;
 		}

 		/* safe because sizeof(oneline) == sizeof(buffer) */
 		sprintf(buffer, "%s=%s", name, value);
 		sysctl_write_setting(buffer, output);
 	}
 	fclose(fp);
 	return 0;
 } /* end sysctl_preload_file() */

 /*
  *     Write a single sysctl setting
  */
 static int sysctl_write_setting(const char *setting, int output)
 {
 	int retval = 0;
 	const char *name;
 	const char *value;
 	const char *equals;
 	char *tmpname, *outname, *cptr;
 	int fd = -1;

 	name = setting;
 	equals = strchr(setting, '=');
 	if (!equals) {
 		bb_error_msg(ERR_NO_EQUALS, setting);
 		return -1;
 	}

 	value = equals + 1;	/* point to the value in name=value */
 	if (name == equals || !*value) {
 		bb_error_msg(ERR_MALFORMED_SETTING, setting);
 		return -2;
 	}

 	tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name);
 	outname = xstrdup(tmpname + strlen_PROC_SYS);

 	while ((cptr = strchr(tmpname, '.')) != NULL)
 		*cptr = '/';

 	while ((cptr = strchr(outname, '/')) != NULL)
 		*cptr = '.';

 	fd = open(tmpname, O_WRONLY | O_CREAT | O_TRUNC, 0666);
 	if (fd < 0) {
 		switch (errno) {
 		case ENOENT:
 			bb_error_msg(ERR_INVALID_KEY, outname);
 			break;
 		case EACCES:
 			bb_perror_msg(ERR_PERMISSION_DENIED, outname);
 			break;
 		default:
 			bb_perror_msg(ERR_UNKNOWN_WRITING, outname);
 			break;
 		}
 		retval = -1;
 	} else {
 		dwrite_str(fd, value);
 		close(fd);
 		if (output) {
 			dwrite_str(STDOUT_FILENO, outname);
 			dwrite_str(STDOUT_FILENO, " = ");
 		}
 		dwrite_str(STDOUT_FILENO, value);
 		dwrite_str(STDOUT_FILENO, "\n");
 	}

 	free(tmpname);
 	free(outname);
 	return retval;
 } /* end sysctl_write_setting() */

 /*
  *     Read a sysctl setting
  */
 static int sysctl_read_setting(const char *setting, int output)
 {
 	int retval = 0;
 	char *tmpname, *outname, *cptr;
 	char inbuf[1025];
 	const char *name;
 	FILE *fp;

 	if (!*setting)
 		bb_error_msg(ERR_INVALID_KEY, setting);

 	name = setting;
 	tmpname = concat_path_file(PROC_SYS, name);
 	outname = xstrdup(tmpname + strlen_PROC_SYS);

 	while ((cptr = strchr(tmpname, '.')) != NULL)
 		*cptr = '/';
 	while ((cptr = strchr(outname, '/')) != NULL)
 		*cptr = '.';

 	fp = fopen(tmpname, "r");
 	if (fp == NULL) {
 		switch (errno) {
 		case ENOENT:
 			bb_error_msg(ERR_INVALID_KEY, outname);
 			break;
 		case EACCES:
 			bb_error_msg(ERR_PERMISSION_DENIED, outname);
 			break;
 		default:
 			bb_perror_msg(ERR_UNKNOWN_READING, outname);
 			break;
 		}
 		retval = -1;
 	} else {
 		while (fgets(inbuf, sizeof(inbuf) - 1, fp)) {
 			if (output) {
 				dwrite_str(STDOUT_FILENO, outname);
 				dwrite_str(STDOUT_FILENO, " = ");
 			}
 			dwrite_str(STDOUT_FILENO, inbuf);
 		}
 		fclose(fp);
 	}

 	free(tmpname);
 	free(outname);
 	return retval;
 } /* end sysctl_read_setting() */

 /*
  *     Display all the sysctl settings
  */
 static int sysctl_display_all(const char *path, int output, int show_table)
 {
 	int retval = 0;
 	DIR *dp;
 	struct dirent *de;
 	char *tmpdir;
 	struct stat ts;

 	dp = opendir(path);
 	if (!dp) {
 		return -1;
 	}
 	while ((de = readdir(dp)) != NULL) {
 		tmpdir = concat_subpath_file(path, de->d_name);
 		if (tmpdir == NULL)
 			continue;
 		if (stat(tmpdir, &ts) != 0) {
 			bb_perror_msg(tmpdir);
 		} else if (S_ISDIR(ts.st_mode)) {
 			sysctl_display_all(tmpdir, output, show_table);
 		} else {
 			retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS, output);
 		}
 		free(tmpdir);
 	} /* end while */
 	closedir(dp);

 	return retval;
 } /* end sysctl_display_all() */
	/* vi: set sw=4 ts=4: */
	/*
	* Sysctl 1.01 - A utility to read and manipulate the sysctl parameters
	*
	* Copyright 1999 George Staikos
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*
	* Changelog:
	* v1.01:
	* - added -p <preload> to preload values from a file
	* v1.01.1
	* - busybox applet aware by <solar@gentoo.org>
	*
	*/

	#include "libbb.h"

	/*
	* Function Prototypes
	*/
	static int sysctl_read_setting(const char *setting, int output);
	static int sysctl_write_setting(const char *setting, int output);
	static int sysctl_preload_file(const char *filename, int output);
	static int sysctl_display_all(const char *path, int output, int show_table);

	/*
	* Globals...
	*/
	static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf";
	static const char PROC_SYS[] ALIGN1 = "/proc/sys/";
	enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 };

	/* error messages */
	static const char ERR_UNKNOWN_PARAMETER[] ALIGN1 =
	"error: unknown parameter '%s'";
	static const char ERR_MALFORMED_SETTING[] ALIGN1 =
	"error: malformed setting '%s'";
	static const char ERR_NO_EQUALS[] ALIGN1 =
	"error: '%s' must be of the form name=value";
	static const char ERR_INVALID_KEY[] ALIGN1 =
	"error: '%s' is an unknown key";
	static const char ERR_UNKNOWN_WRITING[] ALIGN1 =
	"error setting key '%s'";
	static const char ERR_UNKNOWN_READING[] ALIGN1 =
	"error reading key '%s'";
	static const char ERR_PERMISSION_DENIED[] ALIGN1 =
	"error: permission denied on key '%s'";
	static const char ERR_PRELOAD_FILE[] ALIGN1 =
	"error: cannot open preload file '%s'";
	static const char WARN_BAD_LINE[] ALIGN1 =
	"warning: %s(%d): invalid syntax, continuing";


	static void dwrite_str(int fd, const char *buf)
	{
	write(fd, buf, strlen(buf));
	}

	/*
	* sysctl_main()...
	*/
	int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int sysctl_main(int argc, char **argv)
	{
	int retval = 0;
	int output = 1;
	int write_mode = 0;
	int switches_allowed = 1;

	if (argc < 2)
	bb_show_usage();

	argv++;

	for (; argv /&& *argv/; argv++) {
	if (switches_allowed && *argv == '-') { / we have a switch */
	switch ((*argv)[1]) {
	case 'n':
	output = 0;
	break;
	case 'w':
	write_mode = 1;
	switches_allowed = 0;
	break;
	case 'p':
	argv++;
	return sysctl_preload_file(((argv /&& *argv/) ? *argv : ETC_SYSCTL_CONF),
	output);
	case 'a':
	case 'A':
	return sysctl_display_all(PROC_SYS, output,
	((*argv)[1] == 'A'));
	default:
	bb_error_msg(ERR_UNKNOWN_PARAMETER, *argv);
	/* fall through */
	//case 'h':
	//case '?':
	bb_show_usage();
	}
	} else {
	switches_allowed = 0;
	if (write_mode)
	retval \|= sysctl_write_setting(*argv, output);
	else
	sysctl_read_setting(*argv, output);
	}
	}
	return retval;
	} /* end sysctl_main() */

	/*
	* sysctl_preload_file
	* preload the sysctl's from a conf file
	* - we parse the file and then reform it (strip out whitespace)
	*/
	#define PRELOAD_BUF 256

	static int sysctl_preload_file(const char *filename, int output)
	{
	int lineno;
	char oneline[PRELOAD_BUF];
	char buffer[PRELOAD_BUF];
	char name, value;
	FILE *fp;

	fp = fopen(filename, "r");
	if (fp == NULL) {
	bb_error_msg_and_die(ERR_PRELOAD_FILE, filename);
	}

	lineno = 0;
	while (fgets(oneline, sizeof(oneline) - 1, fp)) {
	lineno++;
	trim(oneline);
	if (oneline[0] == '#' \|\| oneline[0] == ';')
	continue;
	if (!oneline[0] \|\| !oneline[1])
	continue;

	name = strtok(oneline, "=");
	if (!name) {
	bb_error_msg(WARN_BAD_LINE, filename, lineno);
	continue;
	}
	trim(name);
	if (!*name) {
	bb_error_msg(WARN_BAD_LINE, filename, lineno);
	continue;
	}

	value = strtok(NULL, "\n\r");
	if (!value) {
	bb_error_msg(WARN_BAD_LINE, filename, lineno);
	continue;
	}
	while (value == ' ' \|\| value == '\t')
	value++;
	if (!*value) {
	bb_error_msg(WARN_BAD_LINE, filename, lineno);
	continue;
	}

	/* safe because sizeof(oneline) == sizeof(buffer) */
	sprintf(buffer, "%s=%s", name, value);
	sysctl_write_setting(buffer, output);
	}
	fclose(fp);
	return 0;
	} /* end sysctl_preload_file() */

	/*
	* Write a single sysctl setting
	*/
	static int sysctl_write_setting(const char *setting, int output)
	{
	int retval = 0;
	const char *name;
	const char *value;
	const char *equals;
	char tmpname, outname, *cptr;
	int fd = -1;

	name = setting;
	equals = strchr(setting, '=');
	if (!equals) {
	bb_error_msg(ERR_NO_EQUALS, setting);
	return -1;
	}

	value = equals + 1; /* point to the value in name=value */
	if (name == equals \|\| !*value) {
	bb_error_msg(ERR_MALFORMED_SETTING, setting);
	return -2;
	}

	tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name);
	outname = xstrdup(tmpname + strlen_PROC_SYS);

	while ((cptr = strchr(tmpname, '.')) != NULL)
	*cptr = '/';

	while ((cptr = strchr(outname, '/')) != NULL)
	*cptr = '.';

	fd = open(tmpname, O_WRONLY \| O_CREAT \| O_TRUNC, 0666);
	if (fd < 0) {
	switch (errno) {
	case ENOENT:
	bb_error_msg(ERR_INVALID_KEY, outname);
	break;
	case EACCES:
	bb_perror_msg(ERR_PERMISSION_DENIED, outname);
	break;
	default:
	bb_perror_msg(ERR_UNKNOWN_WRITING, outname);
	break;
	}
	retval = -1;
	} else {
	dwrite_str(fd, value);
	close(fd);
	if (output) {
	dwrite_str(STDOUT_FILENO, outname);
	dwrite_str(STDOUT_FILENO, " = ");
	}
	dwrite_str(STDOUT_FILENO, value);
	dwrite_str(STDOUT_FILENO, "\n");
	}

	free(tmpname);
	free(outname);
	return retval;
	} /* end sysctl_write_setting() */

	/*
	* Read a sysctl setting
	*/
	static int sysctl_read_setting(const char *setting, int output)
	{
	int retval = 0;
	char tmpname, outname, *cptr;
	char inbuf[1025];
	const char *name;
	FILE *fp;

	if (!*setting)
	bb_error_msg(ERR_INVALID_KEY, setting);

	name = setting;
	tmpname = concat_path_file(PROC_SYS, name);
	outname = xstrdup(tmpname + strlen_PROC_SYS);

	while ((cptr = strchr(tmpname, '.')) != NULL)
	*cptr = '/';
	while ((cptr = strchr(outname, '/')) != NULL)
	*cptr = '.';

	fp = fopen(tmpname, "r");
	if (fp == NULL) {
	switch (errno) {
	case ENOENT:
	bb_error_msg(ERR_INVALID_KEY, outname);
	break;
	case EACCES:
	bb_error_msg(ERR_PERMISSION_DENIED, outname);
	break;
	default:
	bb_perror_msg(ERR_UNKNOWN_READING, outname);
	break;
	}
	retval = -1;
	} else {
	while (fgets(inbuf, sizeof(inbuf) - 1, fp)) {
	if (output) {
	dwrite_str(STDOUT_FILENO, outname);
	dwrite_str(STDOUT_FILENO, " = ");
	}
	dwrite_str(STDOUT_FILENO, inbuf);
	}
	fclose(fp);
	}

	free(tmpname);
	free(outname);
	return retval;
	} /* end sysctl_read_setting() */

	/*
	* Display all the sysctl settings
	*/
	static int sysctl_display_all(const char *path, int output, int show_table)
	{
	int retval = 0;
	DIR *dp;
	struct dirent *de;
	char *tmpdir;
	struct stat ts;

	dp = opendir(path);
	if (!dp) {
	return -1;
	}
	while ((de = readdir(dp)) != NULL) {
	tmpdir = concat_subpath_file(path, de->d_name);
	if (tmpdir == NULL)
	continue;
	if (stat(tmpdir, &ts) != 0) {
	bb_perror_msg(tmpdir);
	} else if (S_ISDIR(ts.st_mode)) {
	sysctl_display_all(tmpdir, output, show_table);
	} else {
	retval \|= sysctl_read_setting(tmpdir + strlen_PROC_SYS, output);
	}
	free(tmpdir);
	} /* end while */
	closedir(dp);

	return retval;
	} /* end sysctl_display_all() */