setfiles,restorecon: new SELinux applets by Yuichi Nakamura <ynakam@hitachisoft.jp>

3 files changed, 730 insertions, 0 deletions

diff --git a/selinux/Config.in b/selinux/Config.in
index 42bca66d6..77f89c798 100644
--- a/selinux/Config.in
+++ b/selinux/Config.in
@@ -49,6 +49,14 @@ config MATCHPATHCON
 	  Enable support to get default security context of the
 	  specified path from the file contexts configuration.
 
+config RESTORECON
+	bool "restorecon"
+	default n
+	depends on SELINUX
+	help
+	  Enable support to relabel files. The feature is almost
+	  the same as setfiles, but usage is a little different.
+
 config RUNCON
 	bool "runcon"
 	default n
@@ -78,5 +86,23 @@ config SETENFORCE
 	help
 	  Enable support to modify the mode SELinux is running in.
 
+config SETFILES
+	bool "setfiles"
+	default n
+	depends on SELINUX
+	help
+	  Enable support to modify to relabel files.
+	  Notice: If you built libselinux with -D_FILE_OFFSET_BITS=64,
+	  (It is default in libselinux's Makefile), you _must_ enable
+	  CONFIG_LFS.
+
+config FEATURE_SETFILES_CHECK_OPTION
+	bool "Enable check option"
+	default n
+	depends on SETFILES
+	help
+	  Support "-c" option (check the validity of the contexts against
+	  the specified binary policy) for setfiles. Requires libsepol.
+
 endmenu
 
diff --git a/selinux/Kbuild b/selinux/Kbuild
index 09cae4d2d..08f49c867 100644
--- a/selinux/Kbuild
+++ b/selinux/Kbuild
@@ -14,3 +14,5 @@ lib-$(CONFIG_MATCHPATHCON)	+= matchpathcon.o
 lib-$(CONFIG_RUNCON)		+= runcon.o
 lib-$(CONFIG_SELINUXENABLED)	+= selinuxenabled.o
 lib-$(CONFIG_SETENFORCE)	+= setenforce.o
+lib-$(CONFIG_SETFILES)		+= setfiles.o
+lib-$(CONFIG_RESTORECON)	+= setfiles.o
diff --git a/selinux/setfiles.c b/selinux/setfiles.c
new file mode 100644
index 000000000..42207fcfb
--- /dev/null
+++ b/selinux/setfiles.c
@@ -0,0 +1,702 @@
+/*
+  setfiles: based on policycoreutils 2.0.19
+  policycoreutils was released under GPL 2.
+  Port to BusyBox by 2007 Yuichi Nakamura <ynakam@hitachisoft.jp>
+*/
+
+#include "libbb.h"
+#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
+#include <sepol/sepol.h>
+#endif
+
+#define MAX_EXCLUDES 50
+
+struct edir {
+	char *directory;
+	size_t size;
+};
+
+struct globals {
+	FILE *outfile;
+	char *policyfile;
+	char *rootpath;
+	int rootpathlen;
+	unsigned count;
+	int excludeCtr;
+	int errors;
+	int verbose; /* getopt32 uses it, has to be int */
+	//smallint force;
+	//smallint progress;
+	//smallint debug;
+	//smallint dry_run;
+	//smallint quiet;
+	//smallint ignore_enoent;
+	//smallint take_log;
+	//smallint warn_no_match;
+	smallint recurse; /* Recursive descent */
+	smallint follow_mounts;
+	/* Behavior flags determined based on setfiles vs. restorecon */
+	smallint expand_realpath;  /* Expand paths via realpath */
+	smallint abort_on_error; /* Abort the file tree walk upon an error */
+	int add_assoc; /* Track inode associations for conflict detection */
+	int matchpathcon_flags; /* Flags to matchpathcon */
+	dev_t dev_id; /* Device id where target file exists */
+	int nerr;
+	struct edir excludeArray[MAX_EXCLUDES];
+};
+
+#define G (*(struct globals*)&bb_common_bufsiz1)
+void BUG_setfiles_globals_too_big(void);
+#define INIT_G() do { \
+	if (sizeof(G) > COMMON_BUFSIZE) \
+		BUG_setfiles_globals_too_big(); \
+	/* memset(&G, 0, sizeof(G)); - already is */ \
+} while (0)
+#define outfile            (G.outfile           )
+#define policyfile         (G.policyfile        )
+#define rootpath           (G.rootpath          )
+#define rootpathlen        (G.rootpathlen       )
+#define count              (G.count             )
+#define excludeCtr         (G.excludeCtr        )
+#define errors             (G.errors            )
+#define verbose            (G.verbose           )
+//#define force              (G.force             )
+//#define progress           (G.progress          )
+//#define debug              (G.debug             )
+//#define dry_run            (G.dry_run           )
+//#define quiet              (G.quiet             )
+//#define ignore_enoent      (G.ignore_enoent     )
+//#define take_log           (G.take_log          )
+//#define warn_no_match      (G.warn_no_match     )
+#define recurse            (G.recurse           )
+#define follow_mounts      (G.follow_mounts     )
+#define expand_realpath    (G.expand_realpath   )
+#define abort_on_error     (G.abort_on_error    )
+#define add_assoc          (G.add_assoc         )
+#define matchpathcon_flags (G.matchpathcon_flags)
+#define dev_id             (G.dev_id            )
+#define nerr               (G.nerr              )
+#define excludeArray       (G.excludeArray      )
+
+/* Must match getopt32 string! */
+enum {
+	OPT_d = (1 << 0),
+	OPT_e = (1 << 1),
+	OPT_f = (1 << 2),
+	OPT_i = (1 << 3),
+	OPT_l = (1 << 4),
+	OPT_n = (1 << 5),
+	OPT_p = (1 << 6),
+	OPT_q = (1 << 7),
+	OPT_r = (1 << 8),
+	OPT_s = (1 << 9),
+	OPT_v = (1 << 10),
+	OPT_o = (1 << 11),
+	OPT_F = (1 << 12),
+	OPT_W = (1 << 13),
+	OPT_c = (1 << 14), /* c only for setfiles */
+	OPT_R = (1 << 14), /* R only for restorecon */
+};
+#define FLAG_d_debug         (option_mask32 & OPT_d)
+#define FLAG_e               (option_mask32 & OPT_e)
+#define FLAG_f               (option_mask32 & OPT_f)
+#define FLAG_i_ignore_enoent (option_mask32 & OPT_i)
+#define FLAG_l_take_log      (option_mask32 & OPT_l)
+#define FLAG_n_dry_run       (option_mask32 & OPT_n)
+#define FLAG_p_progress      (option_mask32 & OPT_p)
+#define FLAG_q_quiet         (option_mask32 & OPT_q)
+#define FLAG_r               (option_mask32 & OPT_r)
+#define FLAG_s               (option_mask32 & OPT_s)
+#define FLAG_v               (option_mask32 & OPT_v)
+#define FLAG_o               (option_mask32 & OPT_o)
+#define FLAG_F_force         (option_mask32 & OPT_F)
+#define FLAG_W_warn_no_match (option_mask32 & OPT_W)
+#define FLAG_c               (option_mask32 & OPT_c)
+#define FLAG_R               (option_mask32 & OPT_R)
+
+
+static void qprintf(const char *fmt, ...)
+{
+	/* quiet, do nothing */
+}
+
+static void inc_err(void)
+{
+	nerr++;
+	if (nerr > 9 && !FLAG_d_debug) {
+		bb_error_msg_and_die("exiting after 10 errors");
+	}
+}
+
+static int add_exclude(const char *directory)
+{
+	struct stat sb;
+	size_t len = 0;
+
+	if (directory == NULL || directory[0] != '/') {
+		bb_error_msg("full path required for exclude: %s", directory);
+		return 1;
+	}
+	if (lstat(directory, &sb)) {
+		bb_error_msg("directory \"%s\" not found, ignoring", directory);
+		return 0;
+	}
+	if ((sb.st_mode & S_IFDIR) == 0) {
+		bb_error_msg("\"%s\" is not a directory: mode %o, ignoring",
+			directory, sb.st_mode);
+		return 0;
+	}
+	if (excludeCtr == MAX_EXCLUDES) {
+		bb_error_msg("maximum excludes %d exceeded", MAX_EXCLUDES);
+		return 1;
+	}
+
+	len = strlen(directory);
+	while (len > 1 && directory[len - 1] == '/') {
+		len--;
+	}
+	excludeArray[excludeCtr].directory = xstrndup(directory, len);
+	excludeArray[excludeCtr++].size = len;
+
+	return 0;
+}
+
+static int exclude(const char *file)
+{
+	int i = 0;
+	for (i = 0; i < excludeCtr; i++) {
+		if (strncmp(file, excludeArray[i].directory,
+					excludeArray[i].size) == 0) {
+			if (file[excludeArray[i].size] == '\0'
+			 || file[excludeArray[i].size] == '/') {
+				return 1;
+			}
+		}
+	}
+	return 0;
+}
+
+static int match(const char *name, struct stat *sb, char **con)
+{
+	int ret;
+	char path[PATH_MAX + 1];
+	char *tmp_path = xstrdup(name);
+
+	if (excludeCtr > 0) {
+		if (exclude(name)) {
+			goto err;
+		}
+	}
+	ret = lstat(name, sb);
+	if (ret) {
+		if (FLAG_i_ignore_enoent && errno == ENOENT) {
+			free(tmp_path);
+			return 0;
+		}
+		bb_error_msg("stat(%s)", name);
+		goto err;
+	}
+
+	if (expand_realpath) {
+		if (S_ISLNK(sb->st_mode)) {
+			char *p = NULL;
+			char *file_sep;
+
+			size_t len = 0;
+
+			if (verbose > 1)
+				bb_error_msg("warning! %s refers to a symbolic link, not following last component", name);
+
+			file_sep = strrchr(tmp_path, '/');
+			if (file_sep == tmp_path) {
+				file_sep++;
+				p[0] = '\0';
+				p = path;
+			} else if (file_sep) {
+				*file_sep++ = '\0';
+				p = realpath(tmp_path, path);
+			} else {
+				file_sep = tmp_path;
+				p = realpath("./", path);
+			}
+			if (p)
+				len = strlen(p);
+			if (!p || len + strlen(file_sep) + 2 > PATH_MAX) {
+				bb_perror_msg("realpath(%s) failed", name);
+				goto err;
+			}
+			p += len;
+			/* ensure trailing slash of directory name */
+			if (len == 0 || p[-1] != '/') {
+				*p++ = '/';
+			}
+			strcpy(p, file_sep);
+			name = path;
+			if (excludeCtr > 0 && exclude(name))
+				goto err;
+
+		} else {
+			char *p;
+			p = realpath(name, path);
+			if (!p) {
+				bb_perror_msg("realpath(%s)", name);
+				goto err;
+			}
+			name = p;
+			if (excludeCtr > 0 && exclude(name))
+				goto err;
+		}
+	}
+
+	/* name will be what is matched in the policy */
+	if (NULL != rootpath) {
+		if (0 != strncmp(rootpath, name, rootpathlen)) {
+			bb_error_msg("%s is not located in %s",
+				name, rootpath);
+			goto err;
+		}
+		name += rootpathlen;
+	}
+
+	free(tmp_path);
+	if (rootpath != NULL && name[0] == '\0')
+		/* this is actually the root dir of the alt root */
+		return matchpathcon_index("/", sb->st_mode, con);
+	return matchpathcon_index(name, sb->st_mode, con);
+ err:
+	free(tmp_path);
+	return -1;
+}
+
+/* Compare two contexts to see if their differences are "significant",
+ * or whether the only difference is in the user. */
+static int only_changed_user(const char *a, const char *b)
+{
+	if (FLAG_F_force)
+		return 0;
+	if (!a || !b)
+		return 0;
+	a = strchr(a, ':'); /* Rest of the context after the user */
+	b = strchr(b, ':');
+	if (!a || !b)
+		return 0;
+	return (strcmp(a, b) == 0);
+}
+
+static int restore(const char *file)
+{
+	char *my_file = xstrdup(file);
+	char *my_file_orig = my_file;
+	struct stat my_sb;
+	int i, j, ret;
+	char *context = NULL;
+	char *newcon = NULL;
+	int user_only_changed = 0;
+	size_t len = strlen(my_file);
+	int retval = 0;
+
+	/* Skip the extra slashes at the beginning and end, if present. */
+	if (file[0] == '/' && file[1] == '/')
+		my_file++;
+	if (len > 1 && my_file[len - 1] == '/')
+		my_file[len - 1] = '\0';
+
+	i = match(my_file, &my_sb, &newcon);
+
+	if (i < 0) /* No matching specification. */
+		goto out;
+
+
+	if (FLAG_p_progress) {
+		count++;
+		if (count % 0x400 == 0) { /* every 1024 times */
+			count = (count % (80*0x400));
+			if (count == 0)
+				fputc('\n', stdout);
+			fputc('*', stdout);
+			fflush(stdout);
+		}
+	}
+
+	/*
+	 * Try to add an association between this inode and
+	 * this specification. If there is already an association
+	 * for this inode and it conflicts with this specification,
+	 * then use the last matching specification.
+	 */
+	if (add_assoc) {
+		j = matchpathcon_filespec_add(my_sb.st_ino, i, my_file);
+		if (j < 0)
+			goto err;
+
+		if (j != i) {
+			/* There was already an association and it took precedence. */
+			goto out;
+		}
+	}
+
+	if (FLAG_d_debug)
+		printf("%s: %s matched by %s\n", applet_name, my_file, newcon);
+
+	/* Get the current context of the file. */
+	ret = lgetfilecon_raw(my_file, &context);
+	if (ret < 0) {
+		if (errno == ENODATA) {
+			context = NULL; /* paranoia */
+		} else {
+			bb_perror_msg("lgetfilecon_raw on %s", my_file);
+			goto err;
+		}
+		user_only_changed = 0;
+	} else
+		user_only_changed = only_changed_user(context, newcon);
+
+	/*
+	 * Do not relabel the file if the matching specification is
+	 * <<none>> or the file is already labeled according to the
+	 * specification.
+	 */
+	if ((strcmp(newcon, "<<none>>") == 0)
+	 || (context && (strcmp(context, newcon) == 0) && !FLAG_F_force)) {
+		goto out;
+	}
+
+	if (!FLAG_F_force && context && (is_context_customizable(context) > 0)) {
+		if (verbose > 1) {
+			bb_error_msg("skipping %s. %s is customizable_types",
+				my_file, context);
+		}
+		goto out;
+	}
+
+	if (verbose) {
+		/* If we're just doing "-v", trim out any relabels where
+		 * the user has changed but the role and type are the
+		 * same.  For "-vv", emit everything. */
+		if (verbose > 1 || !user_only_changed) {
+			bb_info_msg("%s: reset %s context %s->%s",
+				applet_name, my_file, context ?: "", newcon);
+		}
+	}
+
+	if (FLAG_l_take_log && !user_only_changed) {
+		if (context)
+			bb_info_msg("relabeling %s from %s to %s", my_file, context, newcon);
+		else
+			bb_info_msg("labeling %s to %s", my_file, newcon);
+	}
+
+	if (outfile && !user_only_changed)
+		fprintf(outfile, "%s\n", my_file);
+
+	/*
+	 * Do not relabel the file if -n was used.
+	 */
+	if (FLAG_n_dry_run || user_only_changed)
+		goto out;
+
+	/*
+	 * Relabel the file to the specified context.
+	 */
+	ret = lsetfilecon(my_file, newcon);
+	if (ret) {
+		bb_perror_msg("lsetfileconon(%s,%s)", my_file, newcon);
+		goto err;
+	}
+
+ out:
+	freecon(context);
+	freecon(newcon);
+	free(my_file_orig);
+	return retval;
+ err:
+	retval--; /* -1 */
+	goto out;
+}
+
+/*
+ * Apply the last matching specification to a file.
+ * This function is called by recursive_action on each file during
+ * the directory traversal.
+ */
+static int apply_spec(const char *file,
+		      struct stat *sb, void *userData, int depth)
+{
+	if (!follow_mounts) {
+		/* setfiles does not process across different mount points */
+		if (sb->st_dev != dev_id) {
+			return SKIP;
+		}
+	}
+	errors |= restore(file);
+	if (abort_on_error && errors)
+		return FALSE;
+	return TRUE;
+}
+
+
+static int canoncon(const char *path, unsigned lineno, char **contextp)
+{
+	static const char err_msg[] = "%s: line %u has invalid context %s";
+
+	char *tmpcon;
+	char *context = *contextp;
+	int invalid = 0;
+
+#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
+	if (policyfile) {
+		if (sepol_check_context(context) >= 0)
+			return 0;
+		/* Exit immediately if we're in checking mode. */
+		bb_error_msg_and_die(err_msg, path, lineno, context);
+	}
+#endif
+
+	if (security_canonicalize_context_raw(context, &tmpcon) < 0) {
+		if (errno != ENOENT) {
+			invalid = 1;
+			inc_err();
+		}
+	} else {
+		free(context);
+		*contextp = tmpcon;
+	}
+
+	if (invalid) {
+		bb_error_msg(err_msg, path, lineno, context);
+	}
+
+	return invalid;
+}
+
+static int process_one(char *name)
+{
+	struct stat sb;
+	int rc;
+
+	rc = lstat(name, &sb);
+	if (rc < 0) {
+		if (FLAG_i_ignore_enoent && errno == ENOENT)
+			return 0;
+		bb_perror_msg("stat(%s)", name);
+		goto err;
+	}
+	dev_id = sb.st_dev;
+
+	if (S_ISDIR(sb.st_mode) && recurse) {
+		if (recursive_action(name,
+				     ACTION_RECURSE,
+				     apply_spec,
+				     apply_spec,
+				     NULL, 0) != TRUE) {
+			bb_error_msg("error while labeling %s", name);
+			goto err;
+		}
+	} else {
+		rc = restore(name);
+		if (rc)
+			goto err;
+	}
+
+ out:
+	if (add_assoc) {
+		if (FLAG_q_quiet)
+			set_matchpathcon_printf(&qprintf);
+		matchpathcon_filespec_eval();
+		set_matchpathcon_printf(NULL);
+		matchpathcon_filespec_destroy();
+	}
+
+	return rc;
+
+ err:
+	rc = -1;
+	goto out;
+}
+
+int setfiles_main(int argc, char **argv);
+int setfiles_main(int argc, char **argv)
+{
+	struct stat sb;
+	int rc, i = 0;
+	const char *input_filename = NULL;
+	int use_input_file = 0;
+	char *buf = NULL;
+	size_t buf_len;
+	int flags;
+	llist_t *exclude_dir = NULL;
+	char *out_filename = NULL;
+
+	INIT_G();
+
+	if (applet_name[0] == 's') { /* "setfiles" */
+		/*
+		 * setfiles:
+		 * Recursive descent,
+		 * Does not expand paths via realpath,
+		 * Aborts on errors during the file tree walk,
+		 * Try to track inode associations for conflict detection,
+		 * Does not follow mounts,
+		 * Validates all file contexts at init time.
+		 */
+		recurse = 1;
+		abort_on_error = 1;
+		add_assoc = 1;
+		/* follow_mounts = 0; - already is */
+		matchpathcon_flags = MATCHPATHCON_VALIDATE | MATCHPATHCON_NOTRANS;
+	} else {
+		/*
+		 * restorecon:
+		 * No recursive descent unless -r/-R,
+		 * Expands paths via realpath,
+		 * Do not abort on errors during the file tree walk,
+		 * Do not try to track inode associations for conflict detection,
+		 * Follows mounts,
+		 * Does lazy validation of contexts upon use.
+		 */
+		expand_realpath = 1;
+		follow_mounts = 1;
+		matchpathcon_flags = MATCHPATHCON_NOTRANS;
+		/* restorecon only */
+		selinux_or_die();
+	}
+
+	set_matchpathcon_flags(matchpathcon_flags);
+
+	opt_complementary = "e::vv:v--p:p--v";
+	/* Option order must match OPT_x definitions! */
+	if (applet_name[0] == 'r') { /* restorecon */
+		flags = getopt32(argc, argv, "de:f:ilnpqrsvo:FWR",
+			&exclude_dir, &input_filename, &out_filename, &verbose);
+	} else { /* setfiles */
+		flags = getopt32(argc, argv, "de:f:ilnpqr:svo:FW"
+				USE_FEATURE_SETFILES_CHECK_OPTION("c:"),
+			&exclude_dir, &input_filename, &rootpath, &out_filename,
+				 USE_FEATURE_SETFILES_CHECK_OPTION(&policyfile,)
+			&verbose);
+	}
+
+#if ENABLE_FEATURE_SETFILES_CHECK_OPTION
+	if ((applet_name[0] == 's') && (flags & OPT_c)) {
+		FILE *policystream;
+
+		policystream = xfopen(policyfile, "r");
+		if (sepol_set_policydb_from_file(policystream) < 0) {
+			bb_error_msg_and_die("sepol_set_policydb_from_file on %s", policyfile);
+		}
+		fclose(policystream);
+
+		/* Only process the specified file_contexts file, not
+		   any .homedirs or .local files, and do not perform
+		   context translations. */
+		set_matchpathcon_flags(MATCHPATHCON_BASEONLY |
+				       MATCHPATHCON_NOTRANS |
+				       MATCHPATHCON_VALIDATE);
+	}
+#endif
+
+	//if (flags & OPT_d) {
+	//	debug = 1;
+	//}
+	if (flags & OPT_e) {
+		if (exclude_dir == NULL) {
+			bb_show_usage();
+		}
+		while (exclude_dir) {
+			if (add_exclude(llist_pop(&exclude_dir)))
+				exit(1);
+		}
+	}
+	//if (flags & OPT_i) {
+	//	ignore_enoent = 1;
+	//}
+	//if (flags & OPT_l) {
+	//	take_log = 1;
+	//}
+	//if (flags & OPT_F) {
+	//	force = 1;
+	//}
+	//if (flags & OPT_n) {
+	//	dry_run = 1;
+	//}
+	if (flags & OPT_o) {
+		outfile = stdout;
+		if (NOT_LONE_CHAR(out_filename, '-')) {
+			outfile = xfopen(out_filename, "w");
+		}
+	}
+	//if (flags & OPT_q) {
+	//	quiet = 1;
+	//}
+	if (applet_name[0] == 'r') { /* restorecon */
+		if (flags & (OPT_r | OPT_R))
+			recurse = 1;
+	} else { /* setfiles */
+		if (flags & OPT_r)
+			rootpathlen = strlen(rootpath);
+	}
+	if (flags & OPT_s) {
+		use_input_file = 1;
+		input_filename = "-";
+		add_assoc = 0;
+	}
+	//if (flags & OPT_p) {
+	//	progress = 1;
+	//}
+	//if (flags & OPT_W) {
+	//	warn_no_match = 1;
+	//}
+
+	if (applet_name[0] == 's') { /* setfiles */
+		/* Use our own invalid context checking function so that
+		   we can support either checking against the active policy or
+		   checking against a binary policy file. */
+		set_matchpathcon_canoncon(&canoncon);
+		if (argc == 1)
+			bb_show_usage();
+		if (stat(argv[optind], &sb) < 0) {
+			bb_perror_msg_and_die("%s", argv[optind]);
+		}
+		if (!S_ISREG(sb.st_mode)) {
+			bb_error_msg_and_die("spec file %s is not a regular file", argv[optind]);
+		}
+		/* Load the file contexts configuration and check it. */
+		rc = matchpathcon_init(argv[optind]);
+		if (rc < 0) {
+			bb_perror_msg_and_die("%s", argv[optind]);
+		}
+
+		optind++;
+
+		if (nerr)
+			exit(1);
+	}
+
+	if (use_input_file) {
+		ssize_t len;
+		FILE *f = stdin;
+
+		if (NOT_LONE_CHAR(input_filename, '-'))
+			f = xfopen(input_filename, "r");
+		while ((len = getline(&buf, &buf_len, f)) > 0) {
+			buf[len - 1] = '\0';
+			errors |= process_one(buf);
+		}
+		if (ENABLE_FEATURE_CLEAN_UP)
+			fclose_if_not_stdin(f);
+	} else {
+		if (optind >= argc)
+			bb_show_usage();
+		for (i = optind; i < argc; i++) {
+			errors |= process_one(argv[i]);
+		}
+	}
+
+	if (FLAG_W_warn_no_match)
+		matchpathcon_checkmatches(argv[0]);
+
+	if (ENABLE_FEATURE_CLEAN_UP && outfile)
+		fclose(outfile);
+
+	return errors;
+}