1 files changed, 250 insertions, 0 deletions
diff --git a/src/runscript.c b/src/runscript.c
new file mode 100644
index 0000000..61b43bf
--- /dev/null
+++ b/src/runscript.c
@@ -0,0 +1,250 @@
+/*
+ * runscript.c
+ * Handle launching of Gentoo init scripts.
+ *
+ * Copyright 1999-2004 Gentoo Foundation
+ * Distributed under the terms of the GNU General Public License v2
+ * $Header$
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <dlfcn.h>
+
+#include "core/debug.h"
+#include "core/misc.h"
+
+#ifndef LIBDIR
+# define LIBDIR		"lib"
+#endif
+
+#define SBIN_RC		"/sbin/rc"
+#define PROFILE_ENV	"/etc/profile.env"
+#define RCSCRIPTS_LIB	"/" LIBDIR "/rcscripts"
+#define SYS_WHITELIST	RCSCRIPTS_LIB "/conf.d/env_whitelist"
+#define USR_WHITELIST	"/etc/conf.d/env_whitelist"
+#define RCSCRIPT_HELP	RCSCRIPTS_LIB "/sh/rc-help.sh"
+#define SELINUX_LIB	RCSCRIPTS_LIB "/runscript_selinux.so"
+#define SOFTLEVEL	"SOFTLEVEL"
+
+#define DEFAULT_PATH	"PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/sbin"
+
+#define IS_SBIN_RC()	(0 == strcmp(caller, SBIN_RC))
+
+static void (*selinux_run_init_old) (void);
+static void (*selinux_run_init_new) (int argc, char **argv);
+
+extern char **environ;
+
+void setup_selinux(int argc, char **argv) {
+	void *lib_handle = NULL;
+	
+	lib_handle = dlopen(SELINUX_LIB, RTLD_NOW | RTLD_GLOBAL);
+	if (NULL != lib_handle) {
+		selinux_run_init_old = dlsym(lib_handle, "selinux_runscript");
+		selinux_run_init_new = dlsym(lib_handle, "selinux_runscript2");
+
+		/* Use new run_init if it exists, else fall back to old */
+		if (NULL != selinux_run_init_new)
+			selinux_run_init_new(argc, argv);
+		else if (NULL != selinux_run_init_old)
+			selinux_run_init_old();
+		else {
+			/* This shouldnt happen... probably corrupt lib */
+			fprintf(stderr, "Run_init is missing from runscript_selinux.so!\n");
+			exit(127);
+		}
+	}
+}
+
+char **get_whitelist(char **whitelist, char *filename) {
+	char *buf = NULL;
+	char *tmp_buf = NULL;
+	char *tmp_p = NULL;
+	char *token = NULL;
+	size_t lenght = 0;
+	int count = 0;
+	int current = 0;
+			
+	if (-1 == file_map(filename, &buf, &lenght))
+		return NULL;
+
+	while (current < lenght) {
+		count = buf_get_line(buf, lenght, current);
+
+		tmp_buf = strndup(&buf[current], count);
+		if (NULL == tmp_buf) {
+			DBG_MSG("Failed to allocate temporary buffer!\n");
+			goto error;
+		}
+		tmp_p = tmp_buf;
+		
+		/* Strip leading spaces/tabs */
+		while ((tmp_p[0] == ' ') || (tmp_p[0] == '\t'))
+			tmp_p++;
+
+		/* Get entry - we do not want comments, and only the first word
+		 * on a line is valid */
+		token = strsep(&tmp_p, "# \t");
+		if (NULL != token && '\0' != token[0]) {
+			tmp_p = strndup(token, strlen(token));
+			STRING_LIST_ADD(whitelist, tmp_p, error);
+		}
+
+		current += count + 1;
+		free(tmp_buf);
+		/* Set to NULL in case we error out above and have
+		 * to free below */
+		tmp_buf = NULL;
+	}
+				
+
+	file_unmap(buf, lenght);
+
+	return whitelist;
+
+error:
+	if (NULL != tmp_buf)
+		free(tmp_buf);
+	file_unmap(buf, lenght);
+	STRING_LIST_FREE(whitelist);
+
+	return NULL;
+}
+
+char **filter_environ(char *caller) {
+	char **myenv = NULL;
+	char **whitelist = NULL;
+	char *env_name = NULL;
+	int check_profile = 1;
+	int count = 0;
+
+	if (NULL != getenv(SOFTLEVEL) && !IS_SBIN_RC())
+		/* Called from /sbin/rc, but not /sbin/rc itself, so current
+		 * environment should be fine */
+		return environ;
+
+	if (1 == is_file(SYS_WHITELIST, 1))
+		whitelist = get_whitelist(whitelist, SYS_WHITELIST);
+	else
+		EWARN("System environment whitelist missing!\n");
+
+	if (1 == is_file(USR_WHITELIST, 1))
+		whitelist = get_whitelist(whitelist, USR_WHITELIST);
+	
+	if (NULL == whitelist)
+		/* If no whitelist is present, revert to old behaviour */
+		return environ;
+		
+	if (1 != is_file(PROFILE_ENV, 1))
+		/* XXX: Maybe warn here? */
+		check_profile = 0;
+	
+	STRING_LIST_FOR_EACH(whitelist, env_name, count) {
+		char *env_var = NULL;
+		char *tmp_p = NULL;
+		int env_len = 0;
+	
+		env_var = getenv(env_name);
+		if (NULL != env_var)
+			goto add_entry;
+
+		if (1 == check_profile) {
+			char *tmp_env_name = NULL;
+			int tmp_len = 0;
+			
+			/* The entries in PROFILE_ENV is of the form:
+			 * export VAR_NAME=value */
+			tmp_len = strlen(env_name) + strlen("export ") + 1;
+			tmp_env_name = calloc(tmp_len, sizeof(char *));
+			if (NULL == tmp_env_name) {
+				DBG_MSG("Failed to allocate temporary buffer!\n");
+				goto error;
+			}
+			snprintf(tmp_env_name, tmp_len, "export %s", env_name);
+			
+			/* Clear errno so that subsequent calls do not trigger
+			 * DBG_MSG */
+			errno = 0;
+			env_var = get_cnf_entry(PROFILE_ENV, tmp_env_name);
+			free(tmp_env_name);
+			if (NULL == env_var && ENOMSG != errno)
+				goto error;
+			else if (NULL != env_var)
+				goto add_entry;
+		}
+
+		continue;
+		
+add_entry:
+		env_len = strlen(env_name) + strlen(env_var) + 2;
+		tmp_p = calloc(env_len, sizeof(char *));
+		if (NULL == tmp_p) {
+			DBG_MSG("Failed to allocate temporary buffer!\n");
+			goto error;
+		}
+		snprintf(tmp_p, env_len, "%s=%s", env_name, env_var);
+		STRING_LIST_ADD(myenv, tmp_p, error);
+	}
+
+	STRING_LIST_FREE(whitelist);
+
+	if (NULL == myenv)
+		/* If all else fails, just add a default PATH */
+		STRING_LIST_ADD(myenv, strdup(DEFAULT_PATH), error);
+	
+	return myenv;
+
+error:
+	STRING_LIST_FREE(myenv);
+	STRING_LIST_FREE(whitelist);
+	
+	return NULL;
+}
+
+int main(int argc, char *argv[]) {
+	char *myargs[32];
+	char **myenv = NULL;
+	char *caller = argv[1];
+	int new = 1;
+	
+	myargs[0] = "runscript";
+	while (argv[new] != 0) {
+		myargs[new] = argv[new];
+		new++;
+	}
+	myargs[new] = NULL;
+
+	/* Do not do help for /sbin/rc */
+	if (argc < 3 && !IS_SBIN_RC()) {
+		execv(RCSCRIPT_HELP, myargs);
+		exit(1);
+	}
+
+	/* Setup a filtered environment according to the whitelist */
+	myenv = filter_environ(caller);
+	if (NULL == myenv) {
+		EWARN("%s: Failed to filter the environment!\n", caller);
+		/* XXX: Might think to bail here, but it could mean the system
+		 *      is rendered unbootable, so rather not */
+		myenv = environ;
+	}
+
+	/* Ok, we are ready to go, so setup selinux if applicable */
+	setup_selinux(argc, argv);
+
+	if (!IS_SBIN_RC()) {
+		if (execve("/sbin/runscript.sh", myargs, myenv) < 0)
+			exit(1);
+	} else {
+		if (execve("/bin/bash", myargs, myenv) < 0)
+			exit(1);
+	}
+
+	return 0;
+}