Import the rest of the core functionality of the internal apparmor

development tree (trunk branch). From svn repo version 6381.

parser/parser_include.c

@@ -0,0 +1,481 @@
+/* $Id: parser_include.c 6168 2006-01-27 20:28:31Z steve $ */
+
+/*
+ *   Copyright (c) 2004, 2005 NOVELL (All rights reserved)
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of version 2 of the GNU General Public
+ *   License published by the Free Software Foundation.
+ *
+ *   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, contact Novell, Inc.
+ */
+
+/* Handle subdomain includes, as a straight forward preprocessing phase.
+   While we are at it we will strip comments.  Why? because it made it
+   easier.
+
+   We support 2 types of includes
+
+#include <name> which searches for the first occurance of name in the
+   subdomain directory path.
+
+#include "name" which will search for a relative or absolute pathed
+   file
+
+-p : preprocess only.  Dump output to stdout
+-I path : add a path to be search by #include < >
+-b path : set the base path to something other than /etc/subdomain.d
+
+*/
+
+#define _GNU_SOURCE	/* for strndup() */
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <libintl.h>
+#include "parser.h"
+#include "parser_include.h"
+#define _(s) gettext(s)
+
+/* An array of search directories, I sure hope 100's enough */
+#define MAX_PATH 100
+
+/* maximum depth of nesting */
+#define MAX_NEST_LEVEL 100
+
+/* Location of the subdomain.conf file */
+#ifdef SUBDOMAIN_CONFDIR
+#define SUBDOMAIN_CONF SUBDOMAIN_CONFDIR "/subdomain.conf"
+#else	/* !defined SUBDOMAIN_CONFDIR */
+#define SUBDOMAIN_CONF "/etc/subdomain.conf"
+#endif	/* SUBDOMAIN_CONFDIR */
+
+static char *path[MAX_PATH] = { NULL };
+static int npath = 0;
+
+static int fgetline(FILE * f, char *buffer, size_t len);
+static int getincludestr(char **inc, int c, FILE *f, int line, char *name,
+			 FILE *out);
+static int stripcomment(char *s);
+static char *stripblanks(char *s);
+static FILE *find_inc_file(char *file);
+static int preprocess(FILE *f, char *name, FILE * out, int nest);
+
+int preprocess_only;
+
+/* default base directory is /etc/subdomain.d, it can be overriden
+   with the -b option. */
+
+static char *basedir;
+static char *default_basedir = "/etc/apparmor.d";
+static char *old_basedir = "/etc/subdomain.d";
+
+/* start parsing.  */
+int do_include_preprocessing(char *profilename)
+{
+	int retval = 0;
+	FILE *tmp, *profile = NULL;
+
+	if (profilename) {
+		profile = fopen(profilename, "r");
+		if (!profile) {
+			PERROR(_("Error: couldn't read profile %s: %s\n"),
+			       profilename, strerror(errno));
+			exit(errno);
+		}
+	} else {
+		profile = stdin;
+	}
+
+	/* Change to the base dir */
+	chdir(basedir);
+
+	if (preprocess_only) {
+		retval = preprocess(profile, profilename ? profilename : "stdin",
+				    stdout, 0);
+		goto out;
+	}
+
+	tmp = tmpfile();
+	if (!tmp) {
+		PERROR(_("Error couldn't allocate temporary file\n"));
+		exit(10);
+	}
+
+	retval = preprocess(profile, profilename ? profilename : "stdin",
+			    tmp, 0);
+
+	rewind(tmp);
+
+	dup2(fileno(tmp), 0);	/* stdin */
+	fclose(tmp);
+
+out:
+	if (profilename)
+		fclose(profile);
+
+	return retval;
+}
+
+/* set up basedir so that it can be overridden/used later. */
+void init_base_dir(void)
+{
+	int rc;
+	struct stat sbuf;
+
+	/* basedir should always start out NULL; if not, something's
+	 * wrong.*/
+	assert(basedir == NULL);
+
+	rc = stat(default_basedir, &sbuf);
+	if (rc == 0 && S_ISDIR(sbuf.st_mode)) {
+		basedir = default_basedir;
+		return;
+	}
+
+	rc = stat(old_basedir, &sbuf);
+	if (rc == 0 && S_ISDIR(sbuf.st_mode)) {
+		basedir = old_basedir;
+		return;
+	}
+}
+
+/* Set the base dir.  Used to change default path for relative includes */
+void set_base_dir(char *dir)
+{
+	char *t;
+	int i, rc;
+	struct stat sbuf;
+
+	t = strndup(dir, PATH_MAX);
+	if (!t) {
+		PERROR(_("Error: Out of Memory\n"));
+		return;
+	}
+
+	/*strip trailing /'s */
+	for (i = strlen(t) - 1; i >= 0 && t[i] == '/'; i--)
+		t[i] = 0;
+
+	rc = stat(t, &sbuf);
+	if (rc == -1 || !S_ISDIR(sbuf.st_mode)) {
+		PERROR(_("basedir %s is not a directory, skipping\n"), t);
+		free(t);
+		return;
+	}
+
+	basedir = t;
+	return;
+}
+
+/* Add a directory to the search path. */
+int add_search_dir(char *dir)
+{
+	char *t;
+	if (npath >= MAX_PATH) {
+		PERROR(_("Error: Can't add directory %s to search path\n"),
+		       dir);
+		return 0;
+	}
+
+	if (strlen(dir) <= 0)
+		return 1;
+
+	t = malloc(strlen(dir) + 1);
+	if (t == NULL) {
+		PERROR(_("Error: Could not allocate memory\n"));
+		return 0;
+	}
+	strcpy(t, dir);
+	/*strip trailing /'s */
+	while (t[strlen(t) - 1] == '/')
+		t[strlen(t) - 1] = 0;
+	path[npath] = t;
+	npath++;
+
+	return 1;
+}
+
+/* Parse Subdomain.conf and put the default dirs in place.  
+
+   subdomain.conf is a shell sourcable file
+   we only parse entries starting with
+   SUBDOMAIN_PATH=
+
+   if there are multiple entries with SUBDOMAIN_PATH=
+   each will get added.
+
+   SUBDOMAIN_PATH=/etc/subdomain.d:/etc/subdomain.d/include
+   is the same as
+   SUBDOMAIN_PATH=/etc/subdomain.d
+   SUBDOMAIN_PATH=/etc/subdomain.d/include */
+void parse_default_paths(void)
+{
+	FILE *f;
+	char buf[1024];
+	char *t, *s;
+	int saved_npath = npath;
+
+	f = fopen(SUBDOMAIN_CONF, "r");
+	if (f == NULL)
+		goto out;
+
+	memset(buf, 0, sizeof(buf));
+
+	while (fgetline(f, buf, 1024)) {
+		if (stripcomment(buf) && (t = strstr(buf, "SUBDOMAIN_PATH="))) {
+			t += 15;
+			/* handle : seperating path elements */
+			do {
+				s = strchr(t, ':');
+				if (s)
+					*s = 0;
+				if (!add_search_dir(stripblanks(t)))
+					break;
+				if (s)
+					t = s + 1;
+			} while (s != NULL);
+		}
+	}
+	fclose(f);
+
+	/* if subdomain.conf doesn't set a base search dir set it to this */
+out:
+	if (npath - saved_npath == 0) {
+		add_search_dir(basedir);
+	}
+}
+
+/* Find the include file by searching the path.
+   Doesn't handle escaped / in file name
+   can we even do that. */
+static FILE *find_inc_file(char *file)
+{
+	int i;
+	FILE *f = NULL;
+	char buf[1024];
+	char *p = NULL;
+
+	if (*file == '\"') {
+		f = fopen(file + 1, "r");
+		if (f) {
+			strncpy(buf, file, 1024);
+			/*scan backwards to the first / or start of string */
+			for (i = strlen(file) - 1; i >= 0; i--) {
+				if (buf[i] == '/')
+					break;
+			}
+			if (i > 0)
+				buf[i] = 0;
+			p = buf;
+		}
+	} else {
+		for (i = 0; i < npath; i++) {
+			snprintf(buf, 1024, "%s/%s", path[i], file + 1);
+			f = fopen(buf, "r");
+			p = path[i];
+			if (f)
+				break;
+		}
+	}
+
+	return f;
+}
+
+const char incword[] = "include";
+
+/* getincludestr:
+ * returns !0 if error occurred
+ * include string (or not) is returned in 'inc'
+ */
+static int getincludestr(char **inc, int c, FILE *f, int line, char *name,
+			 FILE *out)
+{
+	char *b;
+	size_t i = 0, a;
+	int d;
+	int retval = 0;
+
+	*inc = NULL;
+
+	if (c != '#')
+		return retval;
+
+	/* we either have a comment or an include, either process the include
+	   or strip the comment to the eol.  Leave the eol char so line count
+	   gets properly incremented. */
+
+	for (i = 0; i < strlen(incword); i++) {
+		c = fgetc(f);
+		if (c == EOF || c == '\n' || c != incword[i]) {
+			ungetc(c, f);
+			goto comment;
+		}
+	}
+
+	/* found "#include" now search for the file name to include */
+	b = malloc(2048);
+	if (!b) {
+		PERROR(_("Error: could not allocate buffer for include. line %d in %s\n"),
+		       line, name);
+		retval = 1;
+		goto comment;
+	}
+
+	c = fgetc(f);
+	if (!isspace(c)) {
+		ungetc(c, f);
+		goto comment;
+	}
+
+	while ((c = fgetc(f)) != EOF && c != '\n' && isspace(c))
+		/* eat whitespace */ ;
+	if (c != '\"' && c != '<') {
+		free(b);
+		PERROR(_("Error: bad include. line %d in %s\n"), line, name);
+		if (c == '\n')
+			ungetc(c, f);
+		retval = 1;
+		goto comment;
+	}
+
+	b[0] = c;
+	i = 1;
+	while ((d = fgetc(f)) != EOF && d != '\n'
+	       && d != (c == '<' ? '>' : '\"') && i < 2048)
+		b[i++] = d;
+
+	if (d == (c == '<' ? '>' : '\"')) {
+		b[i] = 0;
+		*inc = b;
+		return retval;
+	}
+
+	free(b);
+	PERROR(_("Error: bad include. line %d in %s\n"), line, name);
+	ungetc(d, f);
+	retval = 1;
+	/* fall through to comment - this makes trailing stuff a comment */
+
+      comment:
+	fputc('#', out);
+	for (a = 0; a < i; a++) {
+		fputc(incword[a], out);
+	}
+	while ((c = fgetc(f)) != EOF && c != '\n')
+		fputc(c, out);
+	if (c == '\n')
+		ungetc(c, f);
+
+	return retval;
+}
+
+static int preprocess(FILE * f, char *name, FILE * out, int nest)
+{
+	int line = 1;
+	int c;
+	int retval = 0;
+
+	char *inc = NULL;
+	FILE *newf;
+
+	char cwd[1024];
+
+	if (nest > MAX_NEST_LEVEL) {
+		PERROR(_("Error: exceeded %d levels of includes.  NOT processing %s include\n"),
+		       MAX_NEST_LEVEL, name);
+		return 1;
+	}
+
+	if (nest == 0) {
+		fprintf(out, "\n#source %s\n", name);
+	} else {
+		fprintf(out, "\n#included %s\n", name);
+	}
+
+	while ((c = fgetc(f)) != EOF) {
+		int err = getincludestr(&inc, c, f, line, name, out);
+		if (err)
+			retval = err;
+		if (inc) {
+			getcwd(cwd, 1024);
+			newf = find_inc_file(inc);
+			if (newf) {
+				err = preprocess(newf, inc + 1, out, nest + 1);
+				if (err)
+					retval = err;
+				fclose(newf);
+				chdir(cwd);
+			} else {
+				PERROR(_("Error: #include %s%c not found. line %d in %s\n"),
+				       inc,
+				       *inc == '<' ? '>' : '\"',
+				       line,
+				       name);
+				retval = 1;
+			}
+			free(inc);
+		} else {
+			if (c != '#')
+				fputc(c, out);
+			if (c == '\n')
+				line++;
+		}
+	}
+	return retval;
+}
+
+/* get a line from the file.  If it is to long truncate it. */
+static int fgetline(FILE * f, char *buffer, size_t len)
+{
+	char *b = buffer;
+	int c;
+
+	while (((c = fgetc(f)) != EOF) && (c != '\n')
+	       && (strlen(buffer) < len - 1)) {
+		*b = c;
+		b++;
+	}
+	*b = '\0';
+	if (c != EOF)
+		return 1;
+	return 0;
+}
+
+/* If there is a comment null terminate the string,
+   return strlen of the stripped string*/
+static int stripcomment(char *s)
+{
+	char *t = s;
+	while (*s != '#' && *s != 0)
+		s++;
+	*s = 0;
+
+	return strlen(t);
+}
+
+static char *stripblanks(char *s)
+{
+	char *c;
+
+	while (isspace(*s))
+		s++;
+	c = s;
+	while (!isspace(*s) && *s != 0)
+		s++;
+	*s = 0;
+	return c;
+}