[TOMOYO #15 5/8] Domain transition handler.

Kentaro Takeda
2009-02-05T09:07:46Z

This file controls domain creation/deletion/transition.

Every process belongs to a domain in TOMOYO Linux.
Domain transition occurs when execve(2) is called
and the domain is expressed as 'process invocation history',
such as '<kernel> /sbin/init /etc/init.d/rc'.
Domain information is stored in current->cred->security field.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
---
security/tomoyo/domain.c | 878 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 878 insertions(+)

--- /dev/null
+++ security-testing-2.6.git/security/tomoyo/domain.c
@@ -0,0 +1,878 @@
+/*
+ * security/tomoyo/domain.c
+ *
+ * Implementation of the Domain-Based Mandatory Access Control.
+ *
+ * Copyright (C) 2005-2009 NTT DATA CORPORATION
+ *
+ * Version: 2.2.0-pre 2009/02/01
+ *
+ */
+
+#include "common.h"
+#include "tomoyo.h"
+#include "realpath.h"
+#include <linux/binfmts.h>
+
+/* Variables definitions.*/
+
+/* The initial domain. */
+struct tomoyo_domain_info tomoyo_kernel_domain;
+
+/* The list for "struct tomoyo_domain_info". */
+LIST_HEAD(tomoyo_domain_list);
+DECLARE_RWSEM(tomoyo_domain_list_lock);
+
+/* Structure for "initialize_domain" and "no_initialize_domain" keyword. */
+struct tomoyo_domain_initializer_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *domainname; /* This may be NULL */
+ const struct tomoyo_path_info *program;
+ bool is_deleted;
+ bool is_not; /* True if this entry is "no_initialize_domain". */
+ /* True if the domainname is tomoyo_get_last_name(). */
+ bool is_last_name;
+};
+
+/* Structure for "keep_domain" and "no_keep_domain" keyword. */
+struct tomoyo_domain_keeper_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *domainname;
+ const struct tomoyo_path_info *program; /* This may be NULL */
+ bool is_deleted;
+ bool is_not; /* True if this entry is "no_keep_domain". */
+ /* True if the domainname is tomoyo_get_last_name(). */
+ bool is_last_name;
+};
+
+/* Structure for "alias" keyword. */
+struct tomoyo_alias_entry {
+ struct list_head list;
+ const struct tomoyo_path_info *original_name;
+ const struct tomoyo_path_info *aliased_name;
+ bool is_deleted;
+};
+
+/**
+ * tomoyo_set_domain_flag - Set or clear domain's attribute flags.
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ * @is_delete: True if it is a delete request.
+ * @flags: Flags to set or clear.
+ *
+ * Returns nothing.
+ */
+void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain,
+ const bool is_delete, const u8 flags)
+{
+ /* We need to serialize because this is bitfield operation. */
+ static DEFINE_SPINLOCK(lock);
+ /***** CRITICAL SECTION START *****/
+ spin_lock(&lock);
+ if (!is_delete)
+ domain->flags |= flags;
+ else
+ domain->flags &= ~flags;
+ spin_unlock(&lock);
+ /***** CRITICAL SECTION END *****/
+}
+
+/**
+ * tomoyo_get_last_name - Get last component of a domainname.
+ *
+ * @domain: Pointer to "struct tomoyo_domain_info".
+ *
+ * Returns the last component of the domainname.
+ */
+const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain)
+{
+ const char *cp0 = domain->domainname->name;
+ const char *cp1 = strrchr(cp0, ' ');
+
+ if (cp1)
+ return cp1 + 1;
+ return cp0;
+}
+
+/* The list for "struct tomoyo_domain_initializer_entry". */
+static LIST_HEAD(tomoyo_domain_initializer_list);
+static DECLARE_RWSEM(tomoyo_domain_initializer_list_lock);
+
+/**
+ * tomoyo_update_domain_initializer_entry - Update "struct tomoyo_domain_initializer_entry" list.
+ *
+ * @domainname: The name of domain. May be NULL.
+ * @program: The name of program.
+ * @is_not: True if it is "no_initialize_domain" entry.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_update_domain_initializer_entry(const char *domainname,
+ const char *program,
+ const bool is_not,
+ const bool is_delete)
+{
+ struct tomoyo_domain_initializer_entry *new_entry;
+ struct tomoyo_domain_initializer_entry *ptr;
+ const struct tomoyo_path_info *saved_program;
+ const struct tomoyo_path_info *saved_domainname = NULL;
+ int error = -ENOMEM;
+ bool is_last_name = false;
+
+ if (!tomoyo_is_correct_path(program, 1, -1, -1, __func__))
+ return -EINVAL; /* No patterns allowed. */
+ if (domainname) {
+ if (!tomoyo_is_domain_def(domainname) &&
+ tomoyo_is_correct_path(domainname, 1, -1, -1, __func__))
+ is_last_name = true;
+ else if (!tomoyo_is_correct_domain(domainname, __func__))
+ return -EINVAL;
+ saved_domainname = tomoyo_save_name(domainname);
+ if (!saved_domainname)
+ return -ENOMEM;
+ }
+ saved_program = tomoyo_save_name(program);
+ if (!saved_program)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_initializer_list_lock);
+ list_for_each_entry(ptr, &tomoyo_domain_initializer_list, list) {
+ if (ptr->is_not != is_not ||
+ ptr->domainname != saved_domainname ||
+ ptr->program != saved_program)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->domainname = saved_domainname;
+ new_entry->program = saved_program;
+ new_entry->is_not = is_not;
+ new_entry->is_last_name = is_last_name;
+ list_add_tail(&new_entry->list, &tomoyo_domain_initializer_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_domain_initializer_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return error;
+}
+
+/**
+ * tomoyo_read_domain_initializer_policy - Read "struct tomoyo_domain_initializer_entry" list.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = true;
+
+ down_read(&tomoyo_domain_initializer_list_lock);
+ list_for_each_cookie(pos, head->read_var2,
+ &tomoyo_domain_initializer_list) {
+ const char *no;
+ const char *from = "";
+ const char *domain = "";
+ struct tomoyo_domain_initializer_entry *ptr;
+ ptr = list_entry(pos, struct tomoyo_domain_initializer_entry,
+ list);
+ if (ptr->is_deleted)
+ continue;
+ no = ptr->is_not ? "no_" : "";
+ if (ptr->domainname) {
+ from = " from ";
+ domain = ptr->domainname->name;
+ }
+ if (!tomoyo_io_printf(head,
+ "%s" TOMOYO_KEYWORD_INITIALIZE_DOMAIN
+ "%s%s%s\n", no, ptr->program->name, from,
+ domain)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_domain_initializer_list_lock);
+ return done;
+}
+
+/**
+ * tomoyo_write_domain_initializer_policy - Write "struct tomoyo_domain_initializer_entry" list.
+ *
+ * @data: String to parse.
+ * @is_not: True if it is "no_initialize_domain" entry.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_write_domain_initializer_policy(char *data, const bool is_not,
+ const bool is_delete)
+{
+ char *cp = strstr(data, " from ");
+
+ if (cp) {
+ *cp = '\0';
+ return tomoyo_update_domain_initializer_entry(cp + 6, data,
+ is_not,
+ is_delete);
+ }
+ return tomoyo_update_domain_initializer_entry(NULL, data, is_not,
+ is_delete);
+}
+
+/**
+ * tomoyo_is_domain_initializer - Check whether the given program causes domainname reinitialization.
+ *
+ * @domainname: The name of domain.
+ * @program: The name of program.
+ * @last_name: The last component of @domainname.
+ *
+ * Returns true if executing @program reinitializes domain transition,
+ * false otherwise.
+ */
+static bool tomoyo_is_domain_initializer(const struct tomoyo_path_info *
+ domainname,
+ const struct tomoyo_path_info *program,
+ const struct tomoyo_path_info *
+ last_name)
+{
+ struct tomoyo_domain_initializer_entry *ptr;
+ bool flag = false;
+
+ down_read(&tomoyo_domain_initializer_list_lock);
+ list_for_each_entry(ptr, &tomoyo_domain_initializer_list, list) {
+ if (ptr->is_deleted)
+ continue;
+ if (ptr->domainname) {
+ if (!ptr->is_last_name) {
+ if (ptr->domainname != domainname)
+ continue;
+ } else {
+ if (tomoyo_pathcmp(ptr->domainname, last_name))
+ continue;
+ }
+ }
+ if (tomoyo_pathcmp(ptr->program, program))
+ continue;
+ if (ptr->is_not) {
+ flag = false;
+ break;
+ }
+ flag = true;
+ }
+ up_read(&tomoyo_domain_initializer_list_lock);
+ return flag;
+}
+
+/* The list for "struct tomoyo_domain_keeper_entry". */
+static LIST_HEAD(tomoyo_domain_keeper_list);
+static DECLARE_RWSEM(tomoyo_domain_keeper_list_lock);
+
+/**
+ * tomoyo_update_domain_keeper_entry - Update "struct tomoyo_domain_keeper_entry" list.
+ *
+ * @domainname: The name of domain.
+ * @program: The name of program. May be NULL.
+ * @is_not: True if it is "no_keep_domain" entry.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_update_domain_keeper_entry(const char *domainname,
+ const char *program,
+ const bool is_not,
+ const bool is_delete)
+{
+ struct tomoyo_domain_keeper_entry *new_entry;
+ struct tomoyo_domain_keeper_entry *ptr;
+ const struct tomoyo_path_info *saved_domainname;
+ const struct tomoyo_path_info *saved_program = NULL;
+ static DEFINE_MUTEX(lock);
+ int error = -ENOMEM;
+ bool is_last_name = false;
+
+ if (!tomoyo_is_domain_def(domainname) &&
+ tomoyo_is_correct_path(domainname, 1, -1, -1, __func__))
+ is_last_name = true;
+ else if (!tomoyo_is_correct_domain(domainname, __func__))
+ return -EINVAL;
+ if (program) {
+ if (!tomoyo_is_correct_path(program, 1, -1, -1, __func__))
+ return -EINVAL;
+ saved_program = tomoyo_save_name(program);
+ if (!saved_program)
+ return -ENOMEM;
+ }
+ saved_domainname = tomoyo_save_name(domainname);
+ if (!saved_domainname)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_keeper_list_lock);
+ list_for_each_entry(ptr, &tomoyo_domain_keeper_list, list) {
+ if (ptr->is_not != is_not ||
+ ptr->domainname != saved_domainname ||
+ ptr->program != saved_program)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->domainname = saved_domainname;
+ new_entry->program = saved_program;
+ new_entry->is_not = is_not;
+ new_entry->is_last_name = is_last_name;
+ list_add_tail(&new_entry->list, &tomoyo_domain_keeper_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_domain_keeper_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return error;
+}
+
+/**
+ * tomoyo_write_domain_keeper_policy - Write "struct tomoyo_domain_keeper_entry" list.
+ *
+ * @data: String to parse.
+ * @is_not: True if it is "no_keep_domain" entry.
+ * @is_delete: True if it is a delete request.
+ *
+ */
+int tomoyo_write_domain_keeper_policy(char *data, const bool is_not,
+ const bool is_delete)
+{
+ char *cp = strstr(data, " from ");
+
+ if (cp) {
+ *cp = '\0';
+ return tomoyo_update_domain_keeper_entry(cp + 6, data, is_not,
+ is_delete);
+ }
+ return tomoyo_update_domain_keeper_entry(data, NULL, is_not, is_delete);
+}
+
+/**
+ * tomoyo_read_domain_keeper_policy - Read "struct tomoyo_domain_keeper_entry" list.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = false;
+
+ down_read(&tomoyo_domain_keeper_list_lock);
+ list_for_each_cookie(pos, head->read_var2,
+ &tomoyo_domain_keeper_list) {
+ struct tomoyo_domain_keeper_entry *ptr;
+ const char *no;
+ const char *from = "";
+ const char *program = "";
+
+ ptr = list_entry(pos, struct tomoyo_domain_keeper_entry, list);
+ if (ptr->is_deleted)
+ continue;
+ no = ptr->is_not ? "no_" : "";
+ if (ptr->program) {
+ from = " from ";
+ program = ptr->program->name;
+ }
+ if (!tomoyo_io_printf(head,
+ "%s" TOMOYO_KEYWORD_KEEP_DOMAIN
+ "%s%s%s\n", no, program, from,
+ ptr->domainname->name)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_domain_keeper_list_lock);
+ return done;
+}
+
+/**
+ * tomoyo_is_domain_keeper - Check whether the given program causes domain transition suppression.
+ *
+ * @domainname: The name of domain.
+ * @program: The name of program.
+ * @last_name: The last component of @domainname.
+ *
+ * Returns true if executing @program supresses domain transition,
+ * false otherwise.
+ */
+static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname,
+ const struct tomoyo_path_info *program,
+ const struct tomoyo_path_info *last_name)
+{
+ struct tomoyo_domain_keeper_entry *ptr;
+ bool flag = false;
+
+ down_read(&tomoyo_domain_keeper_list_lock);
+ list_for_each_entry(ptr, &tomoyo_domain_keeper_list, list) {
+ if (ptr->is_deleted)
+ continue;
+ if (!ptr->is_last_name) {
+ if (ptr->domainname != domainname)
+ continue;
+ } else {
+ if (tomoyo_pathcmp(ptr->domainname, last_name))
+ continue;
+ }
+ if (ptr->program && tomoyo_pathcmp(ptr->program, program))
+ continue;
+ if (ptr->is_not) {
+ flag = false;
+ break;
+ }
+ flag = true;
+ }
+ up_read(&tomoyo_domain_keeper_list_lock);
+ return flag;
+}
+
+/* The list for "struct tomoyo_alias_entry". */
+static LIST_HEAD(tomoyo_alias_list);
+static DECLARE_RWSEM(tomoyo_alias_list_lock);
+
+/**
+ * tomoyo_update_alias_entry - Update "struct tomoyo_alias_entry" list.
+ *
+ * @original_name: The original program's real name.
+ * @aliased_name: The symbolic program's symbolic link's name.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_update_alias_entry(const char *original_name,
+ const char *aliased_name,
+ const bool is_delete)
+{
+ struct tomoyo_alias_entry *new_entry;
+ struct tomoyo_alias_entry *ptr;
+ const struct tomoyo_path_info *saved_original_name;
+ const struct tomoyo_path_info *saved_aliased_name;
+ int error = -ENOMEM;
+
+ if (!tomoyo_is_correct_path(original_name, 1, -1, -1, __func__) ||
+ !tomoyo_is_correct_path(aliased_name, 1, -1, -1, __func__))
+ return -EINVAL; /* No patterns allowed. */
+ saved_original_name = tomoyo_save_name(original_name);
+ saved_aliased_name = tomoyo_save_name(aliased_name);
+ if (!saved_original_name || !saved_aliased_name)
+ return -ENOMEM;
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_alias_list_lock);
+ list_for_each_entry(ptr, &tomoyo_alias_list, list) {
+ if (ptr->original_name != saved_original_name ||
+ ptr->aliased_name != saved_aliased_name)
+ continue;
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+ new_entry = tomoyo_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+ new_entry->original_name = saved_original_name;
+ new_entry->aliased_name = saved_aliased_name;
+ list_add_tail(&new_entry->list, &tomoyo_alias_list);
+ error = 0;
+ out:
+ up_write(&tomoyo_alias_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return error;
+}
+
+/**
+ * tomoyo_read_alias_policy - Read "struct tomoyo_alias_entry" list.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ *
+ * Returns true on success, false otherwise.
+ */
+bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head)
+{
+ struct list_head *pos;
+ bool done = true;
+
+ down_read(&tomoyo_alias_list_lock);
+ list_for_each_cookie(pos, head->read_var2, &tomoyo_alias_list) {
+ struct tomoyo_alias_entry *ptr;
+
+ ptr = list_entry(pos, struct tomoyo_alias_entry, list);
+ if (ptr->is_deleted)
+ continue;
+ if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_ALIAS "%s %s\n",
+ ptr->original_name->name,
+ ptr->aliased_name->name)) {
+ done = false;
+ break;
+ }
+ }
+ up_read(&tomoyo_alias_list_lock);
+ return done;
+}
+
+/**
+ * tomoyo_write_alias_policy - Write "struct tomoyo_alias_entry" list.
+ *
+ * @data: String to parse.
+ * @is_delete: True if it is a delete request.
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_write_alias_policy(char *data, const bool is_delete)
+{
+ char *cp = strchr(data, ' ');
+
+ if (!cp)
+ return -EINVAL;
+ *cp++ = '\0';
+ return tomoyo_update_alias_entry(data, cp, is_delete);
+}
+
+/* Domain create/delete/undelete handler. */
+
+/* #define TOMOYO_DEBUG_DOMAIN_UNDELETE */
+
+/**
+ * tomoyo_delete_domain - Delete a domain.
+ *
+ * @domainname: The name of domain.
+ *
+ * Returns 0.
+ */
+int tomoyo_delete_domain(char *domainname)
+{
+ struct tomoyo_domain_info *domain;
+ struct tomoyo_path_info name;
+
+ name.name = domainname;
+ tomoyo_fill_path_info(&name);
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_list_lock);
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "tomoyo_delete_domain %s\n", domainname);
+ list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ if (tomoyo_pathcmp(domain->domainname, &name))
+ continue;
+ printk(KERN_DEBUG "List: %p %u\n", domain, domain->is_deleted);
+ }
+#endif
+ /* Is there an active domain? */
+ list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ struct tomoyo_domain_info *domain2;
+ /* Never delete tomoyo_kernel_domain */
+ if (domain == &tomoyo_kernel_domain)
+ continue;
+ if (domain->is_deleted ||
+ tomoyo_pathcmp(domain->domainname, &name))
+ continue;
+ /* Mark already deleted domains as non undeletable. */
+ list_for_each_entry(domain2, &tomoyo_domain_list, list) {
+ if (!domain2->is_deleted ||
+ tomoyo_pathcmp(domain2->domainname, &name))
+ continue;
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ if (domain2->is_deleted != 255)
+ printk(KERN_DEBUG
+ "Marked %p as non undeletable\n",
+ domain2);
+#endif
+ domain2->is_deleted = 255;
+ }
+ /* Delete and mark active domain as undeletable. */
+ domain->is_deleted = 1;
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "Marked %p as undeletable\n", domain);
+#endif
+ break;
+ }
+ up_write(&tomoyo_domain_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return 0;
+}
+
+/**
+ * tomoyo_undelete_domain - Undelete a domain.
+ *
+ * @domainname: The name of domain.
+ *
+ * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
+ */
+struct tomoyo_domain_info *tomoyo_undelete_domain(const char *domainname)
+{
+ struct tomoyo_domain_info *domain;
+ struct tomoyo_domain_info *candidate_domain = NULL;
+ struct tomoyo_path_info name;
+
+ name.name = domainname;
+ tomoyo_fill_path_info(&name);
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_list_lock);
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "tomoyo_undelete_domain %s\n", domainname);
+ list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ if (tomoyo_pathcmp(domain->domainname, &name))
+ continue;
+ printk(KERN_DEBUG "List: %p %u\n", domain, domain->is_deleted);
+ }
+#endif
+ list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ if (tomoyo_pathcmp(&name, domain->domainname))
+ continue;
+ if (!domain->is_deleted) {
+ /* This domain is active. I can't undelete. */
+ candidate_domain = NULL;
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "%p is active. I can't undelete.\n",
+ domain);
+#endif
+ break;
+ }
+ /* Is this domain undeletable? */
+ if (domain->is_deleted == 1)
+ candidate_domain = domain;
+ }
+ if (candidate_domain) {
+ candidate_domain->is_deleted = 0;
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "%p was undeleted.\n", candidate_domain);
+#endif
+ }
+ up_write(&tomoyo_domain_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return candidate_domain;
+}
+
+/**
+ * tomoyo_find_or_assign_new_domain - Create a domain.
+ *
+ * @domainname: The name of domain.
+ * @profile: Profile number to assign if the domain was newly created.
+ *
+ * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
+ */
+struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
+ domainname,
+ const u8 profile)
+{
+ struct tomoyo_domain_info *domain = NULL;
+ const struct tomoyo_path_info *saved_domainname;
+
+ /***** EXCLUSIVE SECTION START *****/
+ down_write(&tomoyo_domain_list_lock);
+ domain = tomoyo_find_domain(domainname);
+ if (domain)
+ goto out;
+ if (!tomoyo_is_correct_domain(domainname, __func__))
+ goto out;
+ saved_domainname = tomoyo_save_name(domainname);
+ if (!saved_domainname)
+ goto out;
+ /* Can I reuse memory of deleted domain? */
+ list_for_each_entry(domain, &tomoyo_domain_list, list) {
+ struct task_struct *p;
+ struct tomoyo_acl_info *ptr;
+ bool flag;
+ if (!domain->is_deleted ||
+ domain->domainname != saved_domainname)
+ continue;
+ flag = false;
+ /***** CRITICAL SECTION START *****/
+ read_lock(&tasklist_lock);
+ for_each_process(p) {
+ if (tomoyo_real_domain(p) != domain)
+ continue;
+ flag = true;
+ break;
+ }
+ read_unlock(&tasklist_lock);
+ /***** CRITICAL SECTION END *****/
+ if (flag)
+ continue;
+#ifdef TOMOYO_DEBUG_DOMAIN_UNDELETE
+ printk(KERN_DEBUG "Reusing %p %s\n", domain,
+ domain->domainname->name);
+#endif
+ list_for_each_entry(ptr, &domain->acl_info_list, list) {
+ ptr->type |= TOMOYO_ACL_DELETED;
+ }
+ tomoyo_set_domain_flag(domain, true, domain->flags);
+ domain->profile = profile;
+ domain->quota_warned = false;
+ mb(); /* Avoid out-of-order execution. */
+ domain->is_deleted = 0;
+ goto out;
+ }
+ /* No memory reusable. Create using new memory. */
+ domain = tomoyo_alloc_element(sizeof(*domain));
+ if (domain) {
+ INIT_LIST_HEAD(&domain->acl_info_list);
+ domain->domainname = saved_domainname;
+ domain->profile = profile;
+ list_add_tail(&domain->list, &tomoyo_domain_list);
+ }
+ out:
+ up_write(&tomoyo_domain_list_lock);
+ /***** EXCLUSIVE SECTION END *****/
+ return domain;
+}
+
+/**
+ * tomoyo_find_next_domain - Find a domain.
+ *
+ * @bprm: Pointer to "struct linux_binprm".
+ * @next_domain: Pointer to pointer to "struct tomoyo_domain_info".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_find_next_domain(struct linux_binprm *bprm,
+ struct tomoyo_domain_info **next_domain)
+{
+ /*
+ * This function assumes that the size of buffer returned by
+ * tomoyo_realpath() = TOMOYO_MAX_PATHNAME_LEN.
+ */
+ struct tomoyo_page_buffer *tmp = tomoyo_alloc(sizeof(*tmp));
+ struct tomoyo_domain_info *old_domain = tomoyo_domain();
+ struct tomoyo_domain_info *domain = NULL;
+ const char *old_domain_name = old_domain->domainname->name;
+ const char *original_name = bprm->filename;
+ char *new_domain_name = NULL;
+ char *real_program_name = NULL;
+ char *symlink_program_name = NULL;
+ const u8 mode = tomoyo_check_flags(old_domain, TOMOYO_MAC_FOR_FILE);
+ const bool is_enforce = (mode == 3);
+ int retval = -ENOMEM;
+ struct tomoyo_path_info r; /* real name */
+ struct tomoyo_path_info s; /* symlink name */
+ struct tomoyo_path_info l; /* last name */
+ static bool initialized;
+
+ if (!tmp)
+ goto out;
+
+ if (!initialized) {
+ /*
+ * Built-in initializers. This is needed because policies are
+ * not loaded until starting /sbin/init.
+ */
+ tomoyo_update_domain_initializer_entry(NULL, "/sbin/hotplug",
+ false, false);
+ tomoyo_update_domain_initializer_entry(NULL, "/sbin/modprobe",
+ false, false);
+ initialized = true;
+ }
+
+ /* Get tomoyo_realpath of program. */
+ retval = -ENOENT;
+ /* I hope tomoyo_realpath() won't fail with -ENOMEM. */
+ real_program_name = tomoyo_realpath(original_name);
+ if (!real_program_name)
+ goto out;
+ /* Get tomoyo_realpath of symbolic link. */
+ symlink_program_name = tomoyo_realpath_nofollow(original_name);
+ if (!symlink_program_name)
+ goto out;
+
+ r.name = real_program_name;
+ tomoyo_fill_path_info(&r);
+ s.name = symlink_program_name;
+ tomoyo_fill_path_info(&s);
+ l.name = tomoyo_get_last_name(old_domain);
+ tomoyo_fill_path_info(&l);
+
+ /* Check 'alias' directive. */
+ if (tomoyo_pathcmp(&r, &s)) {
+ struct tomoyo_alias_entry *ptr;
+ /* Is this program allowed to be called via symbolic links? */
+ down_read(&tomoyo_alias_list_lock);
+ list_for_each_entry(ptr, &tomoyo_alias_list, list) {
+ if (ptr->is_deleted ||
+ tomoyo_pathcmp(&r, ptr->original_name) ||
+ tomoyo_pathcmp(&s, ptr->aliased_name))
+ continue;
+ memset(real_program_name, 0, TOMOYO_MAX_PATHNAME_LEN);
+ strncpy(real_program_name, ptr->aliased_name->name,
+ TOMOYO_MAX_PATHNAME_LEN - 1);
+ tomoyo_fill_path_info(&r);
+ break;
+ }
+ up_read(&tomoyo_alias_list_lock);
+ }
+
+ /* Check execute permission. */
+ retval = tomoyo_check_exec_perm(old_domain, &r, tmp);
+ if (retval < 0)
+ goto out;
+
+ new_domain_name = tmp->buffer;
+ if (tomoyo_is_domain_initializer(old_domain->domainname, &r, &l)) {
+ /* Transit to the child of tomoyo_kernel_domain domain. */
+ snprintf(new_domain_name, TOMOYO_MAX_PATHNAME_LEN + 1,
+ TOMOYO_ROOT_NAME " " "%s", real_program_name);
+ } else if (old_domain == &tomoyo_kernel_domain &&
+ !tomoyo_policy_loaded) {
+ /*
+ * Needn't to transit from kernel domain before starting
+ * /sbin/init. But transit from kernel domain if executing
+ * initializers because they might start before /sbin/init.
+ */
+ domain = old_domain;
+ } else if (tomoyo_is_domain_keeper(old_domain->domainname, &r, &l)) {
+ /* Keep current domain. */
+ domain = old_domain;
+ } else {
+ /* Normal domain transition. */
+ snprintf(new_domain_name, TOMOYO_MAX_PATHNAME_LEN + 1,
+ "%s %s", old_domain_name, real_program_name);
+ }
+ if (domain || strlen(new_domain_name) >= TOMOYO_MAX_PATHNAME_LEN)
+ goto done;
+ down_read(&tomoyo_domain_list_lock);
+ domain = tomoyo_find_domain(new_domain_name);
+ up_read(&tomoyo_domain_list_lock);
+ if (domain)
+ goto done;
+ if (is_enforce)
+ goto done;
+ domain = tomoyo_find_or_assign_new_domain(new_domain_name,
+ old_domain->profile);
+ done:
+ if (domain)
+ goto out;
+ printk(KERN_WARNING "TOMOYO-ERROR: Domain '%s' not defined.\n",
+ new_domain_name);
+ if (is_enforce)
+ retval = -EPERM;
+ else
+ tomoyo_set_domain_flag(old_domain, false,
+ TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED);
+ out:
+ tomoyo_free(real_program_name);
+ tomoyo_free(symlink_program_name);
+ *next_domain = domain ? domain : old_domain;
+ tomoyo_free(tmp);
+ return retval;
+}

--