summaryrefslogtreecommitdiffstats
path: root/modules/arch/unix/mod_unixd.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--modules/arch/unix/mod_unixd.c433
1 files changed, 433 insertions, 0 deletions
diff --git a/modules/arch/unix/mod_unixd.c b/modules/arch/unix/mod_unixd.c
new file mode 100644
index 0000000..1baa278
--- /dev/null
+++ b/modules/arch/unix/mod_unixd.c
@@ -0,0 +1,433 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_main.h"
+#include "http_log.h"
+#include "http_core.h"
+#include "mpm_common.h"
+#include "os.h"
+#include "ap_mpm.h"
+#include "mod_unixd.h"
+#include "apr_thread_proc.h"
+#include "apr_strings.h"
+#include "apr_portable.h"
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+/* XXX */
+#include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_GRP_H
+#include <grp.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#ifdef HAVE_SYS_SEM_H
+#include <sys/sem.h>
+#endif
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
+#ifndef DEFAULT_USER
+#define DEFAULT_USER "#-1"
+#endif
+#ifndef DEFAULT_GROUP
+#define DEFAULT_GROUP "#-1"
+#endif
+
+#if 0
+typedef struct {
+ const char *user_name;
+ uid_t user_id;
+ gid_t group_id;
+ const char *chroot_dir;
+} unixd_config_t;
+#else
+/*
+ * TODO: clean up the separation between this code
+ * and its data structures and unixd.c, as shown
+ * by the fact that we include unixd.h. Create
+ * mod_unixd.h which does what we need and
+ * clean up unixd.h for what it no longer needs
+ */
+#include "unixd.h"
+#endif
+
+
+/* Set group privileges.
+ *
+ * Note that we use the username as set in the config files, rather than
+ * the lookup of to uid --- the same uid may have multiple passwd entries,
+ * with different sets of groups for each.
+ */
+
+static int set_group_privs(void)
+{
+ if (!geteuid()) {
+ const char *name;
+
+ /* Get username if passed as a uid */
+
+ if (ap_unixd_config.user_name[0] == '#') {
+ struct passwd *ent;
+ uid_t uid = atol(&ap_unixd_config.user_name[1]);
+
+ if ((ent = getpwuid(uid)) == NULL) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02155)
+ "getpwuid: couldn't determine user name from uid %ld, "
+ "you probably need to modify the User directive",
+ (long)uid);
+ return -1;
+ }
+
+ name = ent->pw_name;
+ }
+ else
+ name = ap_unixd_config.user_name;
+
+#if !defined(OS2)
+ /* OS/2 doesn't support groups. */
+ /*
+ * Set the GID before initgroups(), since on some platforms
+ * setgid() is known to zap the group list.
+ */
+ if (setgid(ap_unixd_config.group_id) == -1) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02156)
+ "setgid: unable to set group id to Group %ld",
+ (long)ap_unixd_config.group_id);
+ return -1;
+ }
+
+ /* Reset `groups' attributes. */
+
+ if (initgroups(name, ap_unixd_config.group_id) == -1) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02157)
+ "initgroups: unable to set groups for User %s "
+ "and Group %ld", name, (long)ap_unixd_config.group_id);
+ return -1;
+ }
+#endif /* !defined(OS2) */
+ }
+ return 0;
+}
+
+
+static int
+unixd_drop_privileges(apr_pool_t *pool, server_rec *s)
+{
+ int rv = set_group_privs();
+
+ if (rv) {
+ return rv;
+ }
+
+ if (NULL != ap_unixd_config.chroot_dir) {
+ if (geteuid()) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02158)
+ "Cannot chroot when not started as root");
+ return rv;
+ }
+
+ if (chdir(ap_unixd_config.chroot_dir) != 0) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02159)
+ "Can't chdir to %s", ap_unixd_config.chroot_dir);
+ return rv;
+ }
+
+ if (chroot(ap_unixd_config.chroot_dir) != 0) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02160)
+ "Can't chroot to %s", ap_unixd_config.chroot_dir);
+ return rv;
+ }
+
+ if (chdir("/") != 0) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02161)
+ "Can't chdir to new root");
+ return rv;
+ }
+ }
+
+ /* Only try to switch if we're running as root */
+ if (!geteuid() && (
+#ifdef _OSD_POSIX
+ os_init_job_environment(NULL, ap_unixd_config.user_name, ap_exists_config_define("DEBUG")) != 0 ||
+#endif
+ setuid(ap_unixd_config.user_id) == -1)) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02162)
+ "setuid: unable to change to uid: %ld",
+ (long) ap_unixd_config.user_id);
+ return rv;
+ }
+#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
+ /* this applies to Linux 2.4+ */
+ if (ap_coredumpdir_configured) {
+ if (prctl(PR_SET_DUMPABLE, 1)) {
+ rv = errno;
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02163)
+ "set dumpable failed - this child will not coredump"
+ " after software errors");
+ return rv;
+ }
+ }
+#endif
+
+ return OK;
+}
+
+
+static const char *
+unixd_set_user(cmd_parms *cmd, void *dummy,
+ const char *arg)
+{
+ const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ if (err != NULL) {
+ return err;
+ }
+
+ ap_unixd_config.user_name = arg;
+ ap_unixd_config.user_id = ap_uname2id(arg);
+#if !defined (BIG_SECURITY_HOLE) && !defined (OS2)
+ if (ap_unixd_config.user_id == 0) {
+ return "Error:\tApache has not been designed to serve pages while\n"
+ "\trunning as root. There are known race conditions that\n"
+ "\twill allow any local user to read any file on the system.\n"
+ "\tIf you still desire to serve pages as root then\n"
+ "\tadd -DBIG_SECURITY_HOLE to the CFLAGS env variable\n"
+ "\tand then rebuild the server.\n"
+ "\tIt is strongly suggested that you instead modify the User\n"
+ "\tdirective in your httpd.conf file to list a non-root\n"
+ "\tuser.\n";
+ }
+#endif
+
+ return NULL;
+}
+
+static const char*
+unixd_set_group(cmd_parms *cmd, void *dummy,
+ const char *arg)
+{
+ const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ if (err != NULL) {
+ return err;
+ }
+
+ ap_unixd_config.group_name = arg;
+ ap_unixd_config.group_id = ap_gname2id(arg);
+
+ return NULL;
+}
+
+static const char*
+unixd_set_chroot_dir(cmd_parms *cmd, void *dummy,
+ const char *arg)
+{
+ const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+ if (err != NULL) {
+ return err;
+ }
+ if (!ap_is_directory(cmd->pool, arg)) {
+ return "ChrootDir must be a valid directory";
+ }
+
+ ap_unixd_config.chroot_dir = arg;
+ return NULL;
+}
+
+static const char *
+unixd_set_suexec(cmd_parms *cmd, void *dummy, int arg)
+{
+ const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+ if (err != NULL) {
+ return err;
+ }
+
+ if (!ap_unixd_config.suexec_enabled && arg) {
+ return apr_pstrcat(cmd->pool, "suEXEC isn't supported: ",
+ ap_unixd_config.suexec_disabled_reason, NULL);
+ }
+
+ if (!arg) {
+ ap_unixd_config.suexec_disabled_reason = "Suexec directive is Off";
+ }
+
+ ap_unixd_config.suexec_enabled = arg;
+ return NULL;
+}
+
+#ifdef AP_SUEXEC_CAPABILITIES
+/* If suexec is using capabilities, don't test for the setuid bit. */
+#define SETUID_TEST(finfo) (1)
+#else
+#define SETUID_TEST(finfo) (finfo.protection & APR_USETID)
+#endif
+
+static int
+unixd_pre_config(apr_pool_t *pconf, apr_pool_t *plog,
+ apr_pool_t *ptemp)
+{
+ apr_finfo_t wrapper;
+ ap_unixd_config.user_name = DEFAULT_USER;
+ ap_unixd_config.user_id = ap_uname2id(DEFAULT_USER);
+ ap_unixd_config.group_name = DEFAULT_GROUP;
+ ap_unixd_config.group_id = ap_gname2id(DEFAULT_GROUP);
+
+ ap_unixd_config.chroot_dir = NULL; /* none */
+
+ /* Check for suexec */
+ ap_unixd_config.suexec_enabled = 0;
+ if ((apr_stat(&wrapper, SUEXEC_BIN, APR_FINFO_NORM, ptemp))
+ == APR_SUCCESS) {
+ if (SETUID_TEST(wrapper) && wrapper.user == 0
+ && (access(SUEXEC_BIN, R_OK|X_OK) == 0)) {
+ ap_unixd_config.suexec_enabled = 1;
+ ap_unixd_config.suexec_disabled_reason = "";
+ }
+ else {
+ ap_unixd_config.suexec_disabled_reason =
+ "Invalid owner or file mode for " SUEXEC_BIN;
+ }
+ }
+ else {
+ ap_unixd_config.suexec_disabled_reason =
+ "Missing suexec binary " SUEXEC_BIN;
+ }
+
+ ap_sys_privileges_handlers(1);
+ return OK;
+}
+
+AP_DECLARE(int) ap_unixd_setup_child(void)
+{
+ if (set_group_privs()) {
+ return -1;
+ }
+
+ if (NULL != ap_unixd_config.chroot_dir) {
+ if (geteuid()) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02164)
+ "Cannot chroot when not started as root");
+ return -1;
+ }
+ if (chdir(ap_unixd_config.chroot_dir) != 0) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02165)
+ "Can't chdir to %s", ap_unixd_config.chroot_dir);
+ return -1;
+ }
+ if (chroot(ap_unixd_config.chroot_dir) != 0) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02166)
+ "Can't chroot to %s", ap_unixd_config.chroot_dir);
+ return -1;
+ }
+ if (chdir("/") != 0) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02167)
+ "Can't chdir to new root");
+ return -1;
+ }
+ }
+
+ /* Only try to switch if we're running as root */
+ if (!geteuid() && (
+#ifdef _OSD_POSIX
+ os_init_job_environment(NULL, ap_unixd_config.user_name, ap_exists_config_define("DEBUG")) != 0 ||
+#endif
+ setuid(ap_unixd_config.user_id) == -1)) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02168)
+ "setuid: unable to change to uid: %ld",
+ (long) ap_unixd_config.user_id);
+ return -1;
+ }
+#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
+ /* this applies to Linux 2.4+ */
+ if (ap_coredumpdir_configured) {
+ if (prctl(PR_SET_DUMPABLE, 1)) {
+ ap_log_error(APLOG_MARK, APLOG_ALERT, errno, NULL, APLOGNO(02169)
+ "set dumpable failed - this child will not coredump"
+ " after software errors");
+ }
+ }
+#endif
+ return 0;
+}
+
+static void unixd_dump_config(apr_pool_t *p, server_rec *s)
+{
+ apr_file_t *out = NULL;
+ apr_uid_t uid = ap_unixd_config.user_id;
+ apr_gid_t gid = ap_unixd_config.group_id;
+ char *no_root = "";
+ if (!ap_exists_config_define("DUMP_RUN_CFG"))
+ return;
+ if (geteuid() != 0)
+ no_root = " not_used";
+ apr_file_open_stdout(&out, p);
+ apr_file_printf(out, "User: name=\"%s\" id=%lu%s\n",
+ ap_unixd_config.user_name, (unsigned long)uid, no_root);
+ apr_file_printf(out, "Group: name=\"%s\" id=%lu%s\n",
+ ap_unixd_config.group_name, (unsigned long)gid, no_root);
+ if (ap_unixd_config.chroot_dir)
+ apr_file_printf(out, "ChrootDir: \"%s\"%s\n",
+ ap_unixd_config.chroot_dir, no_root);
+}
+
+static void unixd_hooks(apr_pool_t *pool)
+{
+ ap_hook_pre_config(unixd_pre_config,
+ NULL, NULL, APR_HOOK_FIRST);
+ ap_hook_test_config(unixd_dump_config,
+ NULL, NULL, APR_HOOK_FIRST);
+ ap_hook_drop_privileges(unixd_drop_privileges,
+ NULL, NULL, APR_HOOK_MIDDLE);
+}
+
+static const command_rec unixd_cmds[] = {
+ AP_INIT_TAKE1("User", unixd_set_user, NULL, RSRC_CONF,
+ "Effective user id for this server"),
+ AP_INIT_TAKE1("Group", unixd_set_group, NULL, RSRC_CONF,
+ "Effective group id for this server"),
+ AP_INIT_TAKE1("ChrootDir", unixd_set_chroot_dir, NULL, RSRC_CONF,
+ "The directory to chroot(2) into"),
+ AP_INIT_FLAG("Suexec", unixd_set_suexec, NULL, RSRC_CONF,
+ "Enable or disable suEXEC support"),
+ {NULL}
+};
+
+AP_DECLARE_MODULE(unixd) = {
+ STANDARD20_MODULE_STUFF,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ unixd_cmds,
+ unixd_hooks
+};
+