X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=procps%2Fsysctl.c;h=6d77185caec8ef5b2c6887b2a1df85f749acab13;hb=22c75924daa41b7ea097796afd4baafa2fc99d05;hp=23fb16e9eaada9d396bd9f9eb0be719f4f4b80fc;hpb=54d10059c93cdbacd709147c1bda45c2039059eb;p=oweals%2Fbusybox.git

diff --git a/procps/sysctl.c b/procps/sysctl.c
index 23fb16e9e..6d77185ca 100644
--- a/procps/sysctl.c
+++ b/procps/sysctl.c
@@ -4,27 +4,43 @@
  *
  * Copyright 1999 George Staikos
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  *
  * Changelog:
- *	v1.01:
- *		- added -p <preload> to preload values from a file
- *	v1.01.1
- *		- busybox applet aware by <solar@gentoo.org>
- *
+ * v1.01   - added -p <preload> to preload values from a file
+ * v1.01.1 - busybox applet aware by <solar@gentoo.org>
  */
+//config:config BB_SYSCTL
+//config:	bool "sysctl (7.4 kb)"
+//config:	default y
+//config:	help
+//config:	Configure kernel parameters at runtime.
 
-#include "libbb.h"
+//applet:IF_BB_SYSCTL(APPLET_NOEXEC(sysctl, sysctl, BB_DIR_SBIN, BB_SUID_DROP, sysctl))
 
-static int sysctl_act_on_setting(char *setting);
-static int sysctl_display_all(const char *path);
-static int sysctl_handle_preload_file(const char *filename);
-static void sysctl_dots_to_slashes(char *name);
+//kbuild:lib-$(CONFIG_BB_SYSCTL) += sysctl.o
 
-static void dwrite_str(int fd, const char *buf)
-{
-	write(fd, buf, strlen(buf));
-}
+//usage:#define sysctl_trivial_usage
+//usage:       "-p [-enq] [FILE...] / [-enqaw] [KEY[=VALUE]]..."
+//usage:#define sysctl_full_usage "\n\n"
+//usage:       "Show/set kernel parameters\n"
+//usage:     "\n	-p	Set values from FILEs (default /etc/sysctl.conf)"
+//usage:     "\n	-e	Don't warn about unknown keys"
+//usage:     "\n	-n	Don't show key names"
+//usage:     "\n	-q      Quiet"
+//usage:     "\n	-a	Show all values"
+/* Same as -a, no need to show it */
+/* //usage:     "\n	-A	Show all values in table form" */
+//usage:     "\n	-w	Set values"
+//usage:
+//usage:#define sysctl_example_usage
+//usage:       "sysctl [-n] [-e] variable...\n"
+//usage:       "sysctl [-n] [-e] [-q] -w variable=value...\n"
+//usage:       "sysctl [-n] [-e] -a\n"
+//usage:       "sysctl [-n] [-e] [-q] -p file	(default /etc/sysctl.conf)\n"
+//usage:       "sysctl [-n] [-e] -A\n"
+
+#include "libbb.h"
 
 enum {
 	FLAG_SHOW_KEYS       = 1 << 0,
@@ -32,72 +48,87 @@ enum {
 	FLAG_TABLE_FORMAT    = 1 << 2, /* not implemented */
 	FLAG_SHOW_ALL        = 1 << 3,
 	FLAG_PRELOAD_FILE    = 1 << 4,
+	/* NB: procps 3.2.8 does not require -w for KEY=VAL to work, it only rejects non-KEY=VAL form */
 	FLAG_WRITE           = 1 << 5,
+	FLAG_QUIET           = 1 << 6,
 };
+#define OPTION_STR "neAapwq"
 
-int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int sysctl_main(int argc UNUSED_PARAM, char **argv)
+static void sysctl_dots_to_slashes(char *name)
 {
-	int retval;
-	int opt;
-
-	opt = getopt32(argv, "+neAapw"); /* '+' - stop on first non-option */
-	argv += optind;
-	opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
-	option_mask32 = opt;
+	char *cptr, *last_good, *end, *slash;
+	char end_ch;
 
-	if (opt & FLAG_PRELOAD_FILE) {
-		option_mask32 |= FLAG_WRITE;
-		/* xchdir("/proc/sys") is inside */
-		return sysctl_handle_preload_file(*argv ? *argv : "/etc/sysctl.conf");
-	}
-	xchdir("/proc/sys");
-	/* xchroot(".") - if you are paranoid */
-	if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
-		return sysctl_display_all(".");
-	}
+	end = strchrnul(name, '=');
 
-	retval = 0;
-	while (*argv) {
-		sysctl_dots_to_slashes(*argv);
-		retval |= sysctl_display_all(*argv);
-		argv++;
+	slash = strchrnul(name, '/');
+	if (slash < end
+	 && strchrnul(name, '.') < slash
+	) {
+		/* There are both dots and slashes, and 1st dot is
+		 * before 1st slash.
+		 * (IOW: not raw, unmangled a/b/c.d format)
+		 *
+		 * procps supports this syntax for names with dots:
+		 *  net.ipv4.conf.eth0/100.mc_forwarding
+		 * (dots and slashes are simply swapped)
+		 */
+		while (end != name) {
+			end--;
+			if (*end == '.') *end = '/';
+			else if (*end == '/') *end = '.';
+		}
+		return;
 	}
+	/* else: use our old behavior: */
 
-	return retval;
-}
-
-/* Set sysctl's from a conf file. Format example:
- * # Controls IP packet forwarding
- * net.ipv4.ip_forward = 0
- */
-static int sysctl_handle_preload_file(const char *filename)
-{
-	char *token[2];
-	parser_t *parser;
+	/* Convert minimum number of '.' to '/' so that
+	 * we end up with existing file's name.
+	 *
+	 * Example from bug 3894:
+	 * net.ipv4.conf.eth0.100.mc_forwarding ->
+	 * net/ipv4/conf/eth0.100/mc_forwarding
+	 * NB: net/ipv4/conf/eth0/mc_forwarding *also exists*,
+	 * therefore we must start from the end, and if
+	 * we replaced even one . -> /, start over again,
+	 * but never replace dots before the position
+	 * where last replacement occurred.
+	 *
+	 * Another bug we later had is that
+	 * net.ipv4.conf.eth0.100
+	 * (without .mc_forwarding) was mishandled.
+	 *
+	 * To set up testing: modprobe 8021q; vconfig add eth0 100
+	 */
+	end_ch = *end;
+	*end = '.'; /* trick the loop into trying full name too */
 
-	parser = config_open(filename);
-	/* Must do it _after_ config_open(): */
-	xchdir("/proc/sys");
-	/* xchroot(".") - if you are paranoid */
-
-// TODO: ';' is comment char too
-	while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) {
-		/* Save ~4 bytes by using parser internals */
-		/* parser->line is big enough for sprintf */
-		sprintf(parser->line, "%s=%s", token[0], token[1]);
-		sysctl_dots_to_slashes(parser->line);
-		sysctl_display_all(parser->line);
+	last_good = name - 1;
+ again:
+	cptr = end;
+	while (cptr > last_good) {
+		if (*cptr == '.') {
+			*cptr = '\0';
+			//bb_error_msg("trying:'%s'", name);
+			if (access(name, F_OK) == 0) {
+				*cptr = '/';
+				//bb_error_msg("replaced:'%s'", name);
+				last_good = cptr;
+				goto again;
+			}
+			*cptr = '.';
+		}
+		cptr--;
 	}
-	if (ENABLE_FEATURE_CLEAN_UP)
-		config_close(parser);
-	return 0;
+	*end = end_ch;
 }
 
 static int sysctl_act_on_setting(char *setting)
 {
 	int fd, retval = EXIT_SUCCESS;
-	char *cptr, *outname, *value;
+	char *cptr, *outname;
+	char *value = value; /* for compiler */
+	bool writing = (option_mask32 & FLAG_WRITE);
 
 	outname = xstrdup(setting);
 
@@ -105,24 +136,32 @@ static int sysctl_act_on_setting(char *setting)
 	while (*cptr) {
 		if (*cptr == '/')
 			*cptr = '.';
+		else if (*cptr == '.')
+			*cptr = '/';
 		cptr++;
 	}
 
-	if (option_mask32 & FLAG_WRITE) {
-		cptr = strchr(setting, '=');
-		if (cptr == NULL) {
+	cptr = strchr(setting, '=');
+	if (cptr)
+		writing = 1;
+	if (writing) {
+		if (!cptr) {
 			bb_error_msg("error: '%s' must be of the form name=value",
 				outname);
 			retval = EXIT_FAILURE;
 			goto end;
 		}
-		value = cptr + 1;	/* point to the value in name=value */
-		if (setting == cptr || !*value) {
+		value = cptr + 1;  /* point to the value in name=value */
+		if (setting == cptr /* "name" can't be empty */
+		 /* || !*value - WRONG: "sysctl net.ipv4.ip_local_reserved_ports=" is a valid syntax (clears the value) */
+		) {
 			bb_error_msg("error: malformed setting '%s'", outname);
 			retval = EXIT_FAILURE;
 			goto end;
 		}
 		*cptr = '\0';
+		outname[cptr - setting] = '\0';
+		/* procps 3.2.7 actually uses these flags */
 		fd = open(setting, O_WRONLY|O_CREAT|O_TRUNC, 0666);
 	} else {
 		fd = open(setting, O_RDONLY);
@@ -130,13 +169,16 @@ static int sysctl_act_on_setting(char *setting)
 
 	if (fd < 0) {
 		switch (errno) {
+		case EACCES:
+			/* Happens for write-only settings, e.g. net.ipv6.route.flush */
+			goto end;
 		case ENOENT:
 			if (option_mask32 & FLAG_SHOW_KEY_ERRORS)
 				bb_error_msg("error: '%s' is an unknown key", outname);
 			break;
 		default:
 			bb_perror_msg("error %sing key '%s'",
-					option_mask32 & FLAG_WRITE ?
+					writing ?
 						"sett" : "read",
 					outname);
 			break;
@@ -145,12 +187,15 @@ static int sysctl_act_on_setting(char *setting)
 		goto end;
 	}
 
-	if (option_mask32 & FLAG_WRITE) {
-		dwrite_str(fd, value);
+	if (writing) {
+//TODO: procps 3.2.7 writes "value\n", note trailing "\n"
+		xwrite_str(fd, value);
 		close(fd);
-		if (option_mask32 & FLAG_SHOW_KEYS)
-			printf("%s = ", outname);
-		puts(value);
+		if (!(option_mask32 & FLAG_QUIET)) {
+			if (option_mask32 & FLAG_SHOW_KEYS)
+				printf("%s = ", outname);
+			puts(value);
+		}
 	} else {
 		char c;
 
@@ -158,6 +203,7 @@ static int sysctl_act_on_setting(char *setting)
 		close(fd);
 		if (value == NULL) {
 			bb_perror_msg("error reading key '%s'", outname);
+			retval = EXIT_FAILURE;
 			goto end;
 		}
 
@@ -184,27 +230,28 @@ static int sysctl_act_on_setting(char *setting)
 	return retval;
 }
 
-static int sysctl_display_all(const char *path)
+static int sysctl_act_recursive(const char *path)
 {
-	DIR *dirp;
 	struct stat buf;
-	struct dirent *entry;
-	char *next;
 	int retval = 0;
 
-	stat(path, &buf);
-	if (S_ISDIR(buf.st_mode) && !(option_mask32 & FLAG_WRITE)) {
+	if (!(option_mask32 & FLAG_WRITE)
+	 && stat(path, &buf) == 0
+	 && S_ISDIR(buf.st_mode)
+	) {
+		struct dirent *entry;
+		DIR *dirp;
+
 		dirp = opendir(path);
 		if (dirp == NULL)
 			return -1;
 		while ((entry = readdir(dirp)) != NULL) {
-			next = concat_subpath_file(
-				path, entry->d_name);
+			char *next = concat_subpath_file(path, entry->d_name);
 			if (next == NULL)
 				continue; /* d_name is "." or ".." */
 			/* if path was ".", drop "./" prefix: */
-			retval |= sysctl_display_all((next[0] == '.' && next[1] == '/') ?
-					    next + 2 : next);
+			retval |= sysctl_act_recursive((next[0] == '.' && next[1] == '/') ?
+					next + 2 : next);
 			free(next);
 		}
 		closedir(dirp);
@@ -217,42 +264,84 @@ static int sysctl_display_all(const char *path)
 	return retval;
 }
 
-static void sysctl_dots_to_slashes(char *name)
+/* Set sysctl's from a conf file. Format example:
+ * # Controls IP packet forwarding
+ * net.ipv4.ip_forward = 0
+ */
+static int sysctl_handle_preload_file(const char *filename)
 {
-	char *cptr, *last_good, *end;
+	char *token[2];
+	parser_t *parser;
+	int parse_flags;
 
-	/* Convert minimum number of '.' to '/' so that
-	 * we end up with existing file's name.
-	 *
-	 * Example from bug 3894:
-	 * net.ipv4.conf.eth0.100.mc_forwarding ->
-	 * net/ipv4/conf/eth0.100/mc_forwarding
-	 * NB: net/ipv4/conf/eth0/mc_forwarding *also exists*,
-	 * therefore we must start from the end, and if
-	 * we replaced even one . -> /, start over again,
-	 * but never replace dots before the position
-	 * where last replacement occurred.
-	 */
-	end = name + strlen(name);
-	last_good = name - 1;
-	*end = '.'; /* trick the loop in trying full name too */
+	parser = config_open(filename);
+	/* Must do it _after_ config_open(): */
+	xchdir("/proc/sys");
 
- again:
-	cptr = end;
-	while (cptr > last_good) {
-		if (*cptr == '.') {
-			*cptr = '\0';
-			//bb_error_msg("trying:'%s'", name);
-			if (access(name, F_OK) == 0) {
-				*cptr = '/';
-				*end = '\0'; /* prevent trailing '/' */
-				//bb_error_msg("replaced:'%s'", name);
-				last_good = cptr;
-				goto again;
-			}
-			*cptr = '.';
-		}
-		cptr--;
+	parse_flags = 0;
+	parse_flags &= ~PARSE_COLLAPSE;   // NO (var==val is not var=val) - treat consecutive delimiters as one
+	parse_flags &= ~PARSE_TRIM;       // NO - trim leading and trailing delimiters
+	parse_flags |= PARSE_GREEDY;      // YES - last token takes entire remainder of the line
+	parse_flags &= ~PARSE_MIN_DIE;    // NO - die if < min tokens found
+	parse_flags &= ~PARSE_EOL_COMMENTS; // NO (only first char) - comments are recognized even if not first char
+	parse_flags |= PARSE_ALT_COMMENTS;// YES - two comment chars: ';' and '#'
+	/* <space><tab><space>#comment is also comment, not strictly 1st char only */
+	parse_flags |= PARSE_WS_COMMENTS; // YES - comments are recognized even if there is whitespace before
+	while (config_read(parser, token, 2, 2, ";#=", parse_flags)) {
+		char *tp;
+
+		trim(token[1]);
+		tp = trim(token[0]);
+		sysctl_dots_to_slashes(token[0]);
+		/* ^^^converted in-place. tp still points to NUL */
+		/* now, add "=TOKEN1" */
+		*tp++ = '=';
+		overlapping_strcpy(tp, token[1]);
+
+		sysctl_act_on_setting(token[0]);
 	}
-	*end = '\0';
+	if (ENABLE_FEATURE_CLEAN_UP)
+		config_close(parser);
+	return 0;
+}
+
+int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int sysctl_main(int argc UNUSED_PARAM, char **argv)
+{
+	int retval;
+	int opt;
+
+	opt = getopt32(argv, "+" OPTION_STR); /* '+' - stop on first non-option */
+	argv += optind;
+	opt ^= (FLAG_SHOW_KEYS | FLAG_SHOW_KEY_ERRORS);
+	option_mask32 = opt;
+
+	if (opt & FLAG_PRELOAD_FILE) {
+		int cur_dir_fd;
+		option_mask32 |= FLAG_WRITE;
+		if (!*argv)
+			*--argv = (char*)"/etc/sysctl.conf";
+		cur_dir_fd = xopen(".", O_RDONLY | O_DIRECTORY);
+		do {
+			/* xchdir("/proc/sys") is inside */
+			sysctl_handle_preload_file(*argv);
+			xfchdir(cur_dir_fd); /* files can be relative, must restore cwd */
+		} while (*++argv);
+		return 0; /* procps-ng 3.3.10 does not flag parse errors */
+	}
+	xchdir("/proc/sys");
+	if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
+		return sysctl_act_recursive(".");
+	}
+
+//TODO: if(!argv[0]) bb_show_usage() ?
+
+	retval = 0;
+	while (*argv) {
+		sysctl_dots_to_slashes(*argv);
+		retval |= sysctl_act_recursive(*argv);
+		argv++;
+	}
+
+	return retval;
 }