[TOMOYO 05/15](repost) Domain transition handler functions.

Kentaro Takeda
2007-10-02T07:33:12Z

Domain transition functions for TOMOYO Linux.
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 task_struct->security.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
security/tomoyo/domain.c | 1256 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1256 insertions(+)

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/security/tomoyo/domain.c 2007-10-02 11:26:21.000000000 +0900
@@ -0,0 +1,1256 @@
+/*
+ * security/tomoyo/domain.c
+ *
+ * Domain transition functions for TOMOYO Linux.
+ */
+
+#include "tomoyo.h"
+#include "realpath.h"
+#include <linux/highmem.h>
+#include <linux/binfmts.h>
+
+/************************* VARIABLES *************************/
+
+/* Lock for appending domain's ACL. */
+DECLARE_MUTEX(domain_acl_lock);
+
+/* Domain creation lock. */
+static DECLARE_MUTEX(new_domain_assign_lock);
+
+/***** The structure for program files to force domain reconstruction. *****/
+
+struct domain_initializer_entry {
+ struct domain_initializer_entry *next;
+ const struct path_info *domainname; /* This may be NULL */
+ const struct path_info *program;
+ u8 is_deleted;
+ u8 is_not;
+ u8 is_last_name;
+};
+
+/***** The structure for domains to not to transit domains. *****/
+
+struct domain_keeper_entry {
+ struct domain_keeper_entry *next;
+ const struct path_info *domainname;
+ const struct path_info *program; /* This may be NULL */
+ u8 is_deleted;
+ u8 is_not;
+ u8 is_last_name;
+};
+
+/***** The structure for program files that should be aggregated. *****/
+
+struct aggregator_entry {
+ struct aggregator_entry *next;
+ const struct path_info *original_name;
+ const struct path_info *aggregated_name;
+ u8 is_deleted;
+};
+
+/***** The structure for program files that should be aliased. *****/
+
+struct alias_entry {
+ struct alias_entry *next;
+ const struct path_info *original_name;
+ const struct path_info *aliased_name;
+ u8 is_deleted;
+};
+
+/************************* UTILITY FUNCTIONS *************************/
+
+/**
+ * tmy_is_domain_def - check if the line is likely a domain definition.
+ * @buffer: the line to check.
+ *
+ * Returns nonzero if @buffer is likely a domain definition.
+ * Returns zero otherwise.
+ *
+ * For complete validation check, use tmy_is_correct_domain().
+ */
+int tmy_is_domain_def(const unsigned char *buffer)
+{
+ return strncmp(buffer, TMY_ROOT_NAME, TMY_ROOT_NAME_LEN) == 0;
+}
+
+/**
+ * tmy_add_acl - add an entry to a domain.
+ * @ptr: pointer to the last "struct acl_info" of @domain. May be NULL.
+ * @domain: pointer to "struct domain_info".
+ * @new_ptr: pointer to "struct acl_info" to add.
+ *
+ * Returns zero.
+ *
+ * To be honest, I can calculate @ptr from @domain.
+ * But since the caller knows @ptr, I use it.
+ */
+int tmy_add_acl(struct acl_info *ptr,
+ struct domain_info *domain,
+ struct acl_info *new_ptr)
+{
+ mb(); /* Instead of using spinlock. */
+
+ if (!ptr)
+ domain->first_acl_ptr = (struct acl_info *) new_ptr;
+ else
+ ptr->next = (struct acl_info *) new_ptr;
+
+ tmy_update_counter(TMY_UPDATE_DOMAINPOLICY);
+ return 0;
+}
+
+/**
+ * tmy_del_acl - remove an entry from a domain
+ * @ptr: pointer to "struct acl_info" to remove.
+ *
+ * Returns zero.
+ *
+ * TOMOYO Linux doesn't free memory used by policy because policies are not
+ * so frequently changed after entring into enforcing mode.
+ * This makes the code free of read-lock.
+ * The caller uses "down(&domain_acl_lock);" as write-lock.
+ */
+int tmy_del_acl(struct acl_info *ptr)
+{
+ ptr->is_deleted = 1;
+ tmy_update_counter(TMY_UPDATE_DOMAINPOLICY);
+ return 0;
+}
+
+/************************ DOMAIN INITIALIZER HANDLER ************************/
+
+static struct domain_initializer_entry *domain_initializer_list;
+
+/* Update domain initializer list. */
+static int tmy_add_domain_initializer_entry(const char *domainname,
+ const char *program,
+ const u8 is_not,
+ const u8 is_delete)
+{
+ struct domain_initializer_entry *new_entry;
+ struct domain_initializer_entry *ptr;
+ static DECLARE_MUTEX(lock);
+ const struct path_info *saved_program;
+ const struct path_info *saved_domainname = NULL;
+ int error = -ENOMEM;
+ u8 is_last_name = 0;
+
+ if (!tmy_correct_path(program, 1, -1, -1, __FUNCTION__))
+ return -EINVAL; /* No patterns allowed. */
+
+ if (domainname) {
+ if (!tmy_is_domain_def(domainname) &&
+ tmy_correct_path(domainname, 1, -1, -1, __FUNCTION__))
+ is_last_name = 1;
+
+ else if (!tmy_is_correct_domain(domainname, __FUNCTION__))
+ return -EINVAL;
+
+ saved_domainname = tmy_save_name(domainname);
+ if (!saved_domainname)
+ return -ENOMEM;
+ }
+
+ saved_program = tmy_save_name(program);
+ if (!saved_program)
+ return -ENOMEM;
+
+ down(&lock);
+
+ for (ptr = domain_initializer_list; ptr; ptr = ptr->next) {
+ if (ptr->is_not == is_not &&
+ ptr->domainname == saved_domainname &&
+ ptr->program == saved_program) {
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ }
+
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+
+ new_entry = tmy_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;
+
+ mb(); /* Instead of using spinlock. */
+ ptr = domain_initializer_list;
+ if (ptr) {
+ while (ptr->next)
+ ptr = ptr->next;
+ ptr->next = new_entry;
+ } else
+ domain_initializer_list = new_entry;
+
+ error = 0;
+out: ;
+
+ up(&lock);
+ return error;
+}
+
+/**
+ * tmy_read_domain_initializer_policy - read domain initializer policy.
+ * @head: pointer to "struct io_buffer".
+ *
+ * Returns nonzero if reading incomplete.
+ * Returns zero otherwise.
+ */
+int tmy_read_domain_initializer_policy(struct io_buffer *head)
+{
+ struct domain_initializer_entry *ptr = head->read_var2;
+
+ if (!ptr)
+ ptr = domain_initializer_list;
+
+ while (ptr) {
+ head->read_var2 = ptr;
+ if (!ptr->is_deleted) {
+ const char *s1 = ptr->is_not ? "no_" : "";
+ const char *s2 = TMY_INITIALIZE_DOMAIN;
+ const char *s3 = ptr->program->name;
+
+ if (ptr->domainname) {
+ if (tmy_io_printf(head, "%s%s%s from %s\n",
+ s1, s2, s3,
+ ptr->domainname->name))
+ break;
+ } else {
+ if (tmy_io_printf(head, "%s%s%s\n",
+ s1, s2, s3))
+ break;
+ }
+ }
+ ptr = ptr->next;
+ }
+
+ return ptr ? -ENOMEM : 0;
+}
+
+/**
+ * tmy_add_domain_initializer_policy - add domain initializer policy
+ * @data: a line to parse.
+ * @is_not: is this overriding?
+ * @is_delete: is this remove request?
+ *
+ * Returns zero on success.
+ * Returns nonzero on failure.
+ *
+ * This function adds or removes a domain initializer entry.
+ */
+int tmy_add_domain_initializer_policy(char *data,
+ const u8 is_not,
+ const u8 is_delete)
+{
+ char *cp = strstr(data, " from ");
+
+ if (cp) {
+ *cp = '\0';
+ return tmy_add_domain_initializer_entry(cp + 6, data, is_not,
+ is_delete);
+ }
+
+ return tmy_add_domain_initializer_entry(NULL, data, is_not, is_delete);
+}
+
+/* Should I transit to a domain under "<kernel>" domain? */
+static int tmy_is_domain_initializer(const struct path_info *domainname,
+ const struct path_info *program,
+ const struct path_info *last_name)
+{
+ struct domain_initializer_entry *ptr;
+ int flag = 0;
+
+ for (ptr = domain_initializer_list; ptr; ptr = ptr->next) {
+ if (ptr->is_deleted)
+ continue;
+
+ if (ptr->domainname) {
+ if (!ptr->is_last_name) {
+ if (ptr->domainname != domainname)
+ continue;
+ } else {
+ if (tmy_pathcmp(ptr->domainname, last_name))
+ continue;
+ }
+ }
+
+ if (tmy_pathcmp(ptr->program, program))
+ continue;
+ if (ptr->is_not)
+ return 0;
+
+ flag = 1;
+ }
+
+ return flag;
+}
+
+/************************* DOMAIN KEEPER HANDLER *************************/
+
+static struct domain_keeper_entry *domain_keeper_list;
+
+/* Update domain keeper list. */
+static int tmy_add_domain_keeper_entry(const char *domainname,
+ const char *program,
+ const u8 is_not,
+ const u8 is_delete)
+{
+ struct domain_keeper_entry *new_entry;
+ struct domain_keeper_entry *ptr;
+ const struct path_info *saved_domainname;
+ const struct path_info *saved_program = NULL;
+ static DECLARE_MUTEX(lock);
+ int error = -ENOMEM;
+ u8 is_last_name = 0;
+
+ if (!tmy_is_domain_def(domainname) &&
+ tmy_correct_path(domainname, 1, -1, -1, __FUNCTION__))
+ is_last_name = 1;
+
+ else if (!tmy_is_correct_domain(domainname, __FUNCTION__))
+ return -EINVAL;
+
+ if (program) {
+ if (!tmy_correct_path(program, 1, -1, -1, __FUNCTION__))
+ return -EINVAL;
+
+ saved_program = tmy_save_name(program);
+ if (!saved_program)
+ return -ENOMEM;
+ }
+
+ saved_domainname = tmy_save_name(domainname);
+ if (!saved_domainname)
+ return -ENOMEM;
+
+ down(&lock);
+
+ for (ptr = domain_keeper_list; ptr; ptr = ptr->next) {
+ if (ptr->is_not == is_not &&
+ ptr->domainname == saved_domainname &&
+ ptr->program == saved_program) {
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ }
+
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+
+ new_entry = tmy_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;
+
+ mb(); /* Instead of using spinlock. */
+ ptr = domain_keeper_list;
+ if (ptr) {
+ while (ptr->next)
+ ptr = ptr->next;
+ ptr->next = new_entry;
+ } else
+ domain_keeper_list = new_entry;
+ error = 0;
+
+out: ;
+
+ up(&lock);
+ return error;
+}
+
+/**
+ * tmy_add_domain_keeper_policy - add domain keeper policy.
+ * @data: a line to parse.
+ * @is_not: is this overriding?
+ * @is_delete: is this remove request?
+ *
+ * Returns zero on success.
+ * Returns nonzero on failure.
+ *
+ * This function adds or removes a domain keeper entry.
+ *
+ */
+int tmy_add_domain_keeper_policy(char *data,
+ const u8 is_not,
+ const u8 is_delete)
+{
+ char *cp = strstr(data, " from ");
+
+ if (cp) {
+ *cp = '\0';
+ return tmy_add_domain_keeper_entry(cp + 6, data,
+ is_not, is_delete);
+ }
+
+ return tmy_add_domain_keeper_entry(data, NULL, is_not, is_delete);
+}
+
+/**
+ * tmy_read_domain_keeper_policy - read domain keeper policy.
+ * @head: pointer to "struct io_buffer".
+ *
+ * Returns nonzero if reading incomplete.
+ * Returns zero otherwise.
+ */
+int tmy_read_domain_keeper_policy(struct io_buffer *head)
+{
+ struct domain_keeper_entry *ptr = head->read_var2;
+
+ if (!ptr)
+ ptr = domain_keeper_list;
+
+ for (; ptr; ptr = ptr->next) {
+ head->read_var2 = ptr;
+ if (ptr->is_deleted)
+ continue;
+
+ if (ptr->program) {
+ if (tmy_io_printf(head,
+ "%s" TMY_KEEP_DOMAIN
+ "%s from %s\n",
+ ptr->is_not ? "no_" : "",
+ ptr->program->name,
+ ptr->domainname->name))
+ break;
+
+ } else {
+ if (tmy_io_printf(head,
+ "%s" TMY_KEEP_DOMAIN
+ "%s\n",
+ ptr->is_not ? "no_" : "",
+ ptr->domainname->name))
+ break;
+
+ }
+ }
+
+ return ptr ? -ENOMEM : 0;
+}
+
+/* Should I remain in current domain? */
+static int tmy_is_domain_keeper(const struct path_info *domainname,
+ const struct path_info *program,
+ const struct path_info *last_name)
+{
+ struct domain_keeper_entry *ptr;
+ int flag = 0;
+
+ for (ptr = domain_keeper_list; ptr; ptr = ptr->next) {
+ if (ptr->is_deleted)
+ continue;
+
+ if (!ptr->is_last_name) {
+ if (ptr->domainname != domainname)
+ continue;
+ } else {
+ if (tmy_pathcmp(ptr->domainname, last_name))
+ continue;
+ }
+
+ if (ptr->program && tmy_pathcmp(ptr->program, program))
+ continue;
+ if (ptr->is_not)
+ return 0;
+ flag = 1;
+ }
+
+ return flag;
+}
+
+/********************* SYMBOLIC LINKED PROGRAM HANDLER *********************/
+
+static struct alias_entry *alias_list;
+
+/* Update alias list. */
+static int tmy_add_alias_entry(const char *original_name,
+ const char *aliased_name,
+ const u8 is_delete)
+{
+ struct alias_entry *new_entry;
+ struct alias_entry *ptr;
+ static DECLARE_MUTEX(lock);
+ const struct path_info *saved_original_name;
+ const struct path_info *saved_aliased_name;
+ int error = -ENOMEM;
+
+ if (!tmy_correct_path(original_name, 1, -1, -1, __FUNCTION__) ||
+ !tmy_correct_path(aliased_name, 1, -1, -1, __FUNCTION__))
+ return -EINVAL; /* No patterns allowed. */
+
+ saved_original_name = tmy_save_name(original_name);
+ saved_aliased_name = tmy_save_name(aliased_name);
+ if (!saved_original_name || !saved_aliased_name)
+ return -ENOMEM;
+
+ down(&lock);
+
+ for (ptr = alias_list; ptr; ptr = ptr->next) {
+ if (ptr->original_name == saved_original_name &&
+ ptr->aliased_name == saved_aliased_name) {
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ }
+
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+
+ new_entry = tmy_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+
+ new_entry->original_name = saved_original_name;
+ new_entry->aliased_name = saved_aliased_name;
+
+ mb(); /* Instead of using spinlock. */
+ ptr = alias_list;
+ if (ptr) {
+ while (ptr->next)
+ ptr = ptr->next;
+ ptr->next = new_entry;
+ } else
+ alias_list = new_entry;
+
+ error = 0;
+out: ;
+
+ up(&lock);
+
+ return error;
+}
+
+/**
+ * tmy_read_alias_policy - read alias policy.
+ * @head: pointer to "struct io_buffer".
+ *
+ * Returns nonzero if reading incomplete.
+ * Returns zero otherwise.
+ */
+int tmy_read_alias_policy(struct io_buffer *head)
+{
+ struct alias_entry *ptr = head->read_var2;
+
+ if (!ptr)
+ ptr = alias_list;
+
+ for (; ptr; ptr = ptr->next) {
+ head->read_var2 = ptr;
+ if (!ptr->is_deleted &&
+ tmy_io_printf(head,
+ TMY_ALIAS "%s %s\n",
+ ptr->original_name->name,
+ ptr->aliased_name->name))
+ break;
+ }
+
+ return ptr ? -ENOMEM : 0;
+}
+
+/**
+ * tmy_add_alias_policy - add alias policy.
+ * @data: a line to parse.
+ * @is_delete: is this remove request?
+ *
+ * Returns zero on success.
+ * Returns nonzero on failure.
+ *
+ * This function adds or removes an alias entry.
+ */
+int tmy_add_alias_policy(char *data, const u8 is_delete)
+{
+ char *cp = strchr(data, ' ');
+
+ if (!cp)
+ return -EINVAL;
+ *cp++ = '\0';
+
+ return tmy_add_alias_entry(data, cp, is_delete);
+}
+
+/************************ DOMAIN AGGREGATOR HANDLER ************************/
+
+static struct aggregator_entry *aggregator_list;
+
+/* Update aggregator list. */
+static int tmy_add_aggregator_entry(const char *original_name,
+ const char *aggregated_name,
+ const u8 is_delete)
+{
+ struct aggregator_entry *new_entry;
+ struct aggregator_entry *ptr;
+ static DECLARE_MUTEX(lock);
+ const struct path_info *saved_original_name;
+ const struct path_info *saved_aggregated_name;
+ int error = -ENOMEM;
+
+ if (!tmy_correct_path(original_name, 1, 0, -1, __FUNCTION__) ||
+ !tmy_correct_path(aggregated_name, 1, -1, -1, __FUNCTION__))
+ return -EINVAL;
+
+ saved_original_name = tmy_save_name(original_name);
+ saved_aggregated_name = tmy_save_name(aggregated_name);
+ if (!saved_original_name || saved_aggregated_name)
+ return -ENOMEM;
+
+ down(&lock);
+
+ for (ptr = aggregator_list; ptr; ptr = ptr->next) {
+ if (ptr->original_name == saved_original_name &&
+ ptr->aggregated_name == saved_aggregated_name) {
+ ptr->is_deleted = is_delete;
+ error = 0;
+ goto out;
+ }
+ }
+
+ if (is_delete) {
+ error = -ENOENT;
+ goto out;
+ }
+
+ new_entry = tmy_alloc_element(sizeof(*new_entry));
+ if (!new_entry)
+ goto out;
+
+ new_entry->original_name = saved_original_name;
+ new_entry->aggregated_name = saved_aggregated_name;
+
+ mb(); /* Instead of using spinlock. */
+ ptr = aggregator_list;
+ if (ptr) {
+ while (ptr->next)
+ ptr = ptr->next;
+ ptr->next = new_entry;
+ } else
+ aggregator_list = new_entry;
+
+ error = 0;
+out: ;
+
+ up(&lock);
+
+ return error;
+}
+
+/**
+ * tmy_read_aggregator_policy - read aggregator policy.
+ * @head: pointer to "struct io_buffer".
+ *
+ * Returns nonzero if reading incomplete.
+ * Returns zero otherwise.
+ */
+int tmy_read_aggregator_policy(struct io_buffer *head)
+{
+ struct aggregator_entry *ptr = head->read_var2;
+
+ if (!ptr)
+ ptr = aggregator_list;
+
+ for (; ptr; ptr = ptr->next) {
+ head->read_var2 = ptr;
+ if (!ptr->is_deleted &&
+ tmy_io_printf(head,
+ TMY_AGGREGATOR "%s %s\n",
+ ptr->original_name->name,
+ ptr->aggregated_name->name))
+ break;
+ }
+
+ return ptr ? -ENOMEM : 0;
+}
+
+/**
+ * tmy_add_aggregator_policy - add aggregator policy.
+ * @data: a line to parse.
+ * @is_delete: is this remove request?
+ *
+ * Returns zero on success.
+ * Returns nonzero on failure.
+ *
+ * This function adds or removes an aggregator entry.
+ */
+int tmy_add_aggregator_policy(char *data, const u8 is_delete)
+{
+ char *cp = strchr(data, ' ');
+
+ if (!cp)
+ return -EINVAL;
+ *cp++ = '\0';
+
+ return tmy_add_aggregator_entry(data, cp, is_delete);
+}
+
+/************************* DOMAIN DELETION HANDLER *************************/
+
+/**
+ * tmy_delete_domain - delete a domain.
+ * @domainname0: domainname to delete.
+ *
+ * Returns zero.
+ *
+ * This function deletes domains.
+ * The behavior of deleting domain is like deleting files on Linux's
+ * filesystem. A process transits to different domain upon do_execve(),
+ * and the process can refer the deleted domains after the domain is deleted,
+ * like a process opens a file and the process can read()/write() the deleted
+ * file after the file is deleted.
+ * This avoids processes from crashing due to referring non-existent domains.
+ * Administrator manually terminates processes thet are referring deleted
+ * domains after deleting domains.
+ * Also, undeleting domains is supported. See tmy_undelete_domain().
+ */
+int tmy_delete_domain(char *domainname0)
+{
+ struct domain_info *domain;
+ struct path_info domainname;
+
+ domainname.name = domainname0;
+ tmy_fill_path_info(&domainname);
+
+ down(&new_domain_assign_lock);
+
+ /* Is there an active domain? */ /* Never delete KERNEL_DOMAIN */
+ for (domain = KERNEL_DOMAIN.next; domain; domain = domain->next) {
+ if (domain->is_deleted ||
+ tmy_pathcmp(domain->domainname, &domainname))
+ continue;
+ break;
+ }
+ if (domain) {
+ struct domain_info *domain2;
+
+ /* Mark already deleted domains as non undeletable. */
+ for (domain2 = KERNEL_DOMAIN.next;
+ domain2;
+ domain2 = domain2->next) {
+ if (!domain2->is_deleted ||
+ tmy_pathcmp(domain2->domainname, &domainname))
+ continue;
+ domain2->is_deleted = 255;
+ }
+
+ /* Delete and mark active domain as undeletable. */
+ domain->is_deleted = 1;
+ }
+
+ up(&new_domain_assign_lock);
+
+ return 0;
+}
+
+/**
+ * tmy_undelete_domain - undelete a domain.
+ * @domainname0: domainname to undelete.
+ *
+ * Returns pointer to undeleted "struct domain_info" on success.
+ * Returns NULL on failure.
+ *
+ * This function undeletes domains.
+ * Not only the domain previously deleted by tmy_delete_domain()
+ * but also all domains deleted by tmy_delete_domain() are undeletable.
+ * If there is no deleted domain named @domainname0 or
+ * a not-yet-deleted domain named @domainname0 exists, undelete fails.
+ * Otherwise, previously deleted domain named @domainname0 is undeleted.
+ */
+struct domain_info *tmy_undelete_domain(const char *domainname0)
+{
+ struct domain_info *domain;
+ struct domain_info *candidate_domain = NULL;
+ struct path_info domainname;
+
+ domainname.name = domainname0;
+ tmy_fill_path_info(&domainname);
+
+ down(&new_domain_assign_lock);
+
+ for (domain = KERNEL_DOMAIN.next; domain; domain = domain->next) {
+ if (tmy_pathcmp(&domainname, domain->domainname))
+ continue;
+
+ if (!domain->is_deleted) {
+ /* This domain is active. I can't undelete. */
+ candidate_domain = NULL;
+ break;
+ }
+
+ /* Is this domain undeletable? */
+ if (domain->is_deleted == 1)
+ candidate_domain = domain;
+ }
+ if (candidate_domain)
+ candidate_domain->is_deleted = 0;
+
+ up(&new_domain_assign_lock);
+
+ return candidate_domain;
+}
+
+/************************ DOMAIN TRANSITION HANDLER ************************/
+
+/**
+ * tmy_find_domain - find a domain with given domainname.
+ * @domainname0: the domainname to find.
+ *
+ * Returns pointer to "struct domain_info" on success.
+ * Returns NULL on failure.
+ *
+ * This function does not create a new domain
+ * if a domain named @domainname0 does not exist.
+ */
+struct domain_info *tmy_find_domain(const char *domainname0)
+{
+ struct domain_info *domain;
+ static int first = 1;
+ struct path_info domainname;
+
+ domainname.name = domainname0;
+ tmy_fill_path_info(&domainname);
+
+ if (first) {
+ KERNEL_DOMAIN.domainname = tmy_save_name(TMY_ROOT_NAME);
+ first = 0;
+ }
+
+ for (domain = &KERNEL_DOMAIN; domain; domain = domain->next) {
+ if (!domain->is_deleted &&
+ !tmy_pathcmp(&domainname, domain->domainname))
+ return domain;
+ }
+
+ return NULL;
+}
+
+/**
+ * tmy_new_domain - find or assign a domain with given domainname.
+ * @domainname: the domainname to find.
+ * @profile: profile number to assign if newly created.
+ *
+ * Returns pointer to "struct domain_info" on success.
+ * Returns NULL on failure.
+ *
+ * This function creates a new domain if a domain named @domainname0
+ * does not exist.
+ */
+struct domain_info *tmy_new_domain(const char *domainname,
+ const u8 profile)
+{
+ struct domain_info *domain = NULL;
+ const struct path_info *saved_domainname;
+
+ down(&new_domain_assign_lock);
+
+ domain = tmy_find_domain(domainname);
+ if (domain)
+ goto out;
+
+ if (!tmy_is_correct_domain(domainname, __FUNCTION__))
+ goto out;
+
+ saved_domainname = tmy_save_name(domainname);
+ if (!saved_domainname)
+ goto out;
+
+ /* Can I reuse memory of deleted domain? */
+ for (domain = KERNEL_DOMAIN.next; domain; domain = domain->next) {
+ struct task_struct *p;
+ struct acl_info *ptr;
+ int flag;
+
+ if (!domain->is_deleted ||
+ domain->domainname != saved_domainname)
+ continue;
+ flag = 0;
+
+ /***** CRITICAL SECTION START *****/
+ read_lock(&tasklist_lock);
+ for_each_process(p) {
+ /* "struct task_struct"->security is not NULL. */
+ if (((struct tmy_security *) p->security)->domain
+ == domain) {
+ flag = 1;
+ break;
+ }
+ }
+ read_unlock(&tasklist_lock);
+ /***** CRITICAL SECTION END *****/
+
+ /* Somebody is still referring this deleted domain. */
+ if (flag)
+ continue;
+
+ /* OK. Let's reuse memory for this deleted domain. */
+
+ /* Delete all entries in this deleted domain. */
+ for (ptr = domain->first_acl_ptr; ptr; ptr = ptr->next)
+ ptr->is_deleted = 1;
+
+ domain->profile = profile;
+ domain->quota_warned = 0;
+
+ mb(); /* Instead of using spinlock. */
+ /* Undelete this deleted domain. */
+ domain->is_deleted = 0;
+ goto out;
+ }
+
+ /* No memory reusable. Create using new memory. */
+ domain = tmy_alloc_element(sizeof(*domain));
+ if (domain) {
+ struct domain_info *ptr = &KERNEL_DOMAIN;
+
+ domain->domainname = saved_domainname;
+ domain->profile = profile;
+
+ mb(); /* Instead of using spinlock. */
+ while (ptr->next)
+ ptr = ptr->next;
+ ptr->next = domain;
+ }
+out: ;
+ up(&new_domain_assign_lock);
+
+ return domain;
+}
+
+/* Convert non ASCII printable characters to ASCII printable characters. */
+static int tmy_escape(char *dest, const char *src, int dest_len)
+{
+ while (*src) {
+ const unsigned char c = *(const unsigned char *) src;
+
+ if (c == '\\') {
+ dest_len -= 2;
+ if (dest_len <= 0)
+ goto out;
+ *dest++ = '\\';
+ *dest++ = '\\';
+ } else if (c > ' ' && c < 127) {
+ if (--dest_len <= 0)
+ goto out;
+ *dest++ = c;
+ } else {
+ dest_len -= 4;
+ if (dest_len <= 0)
+ goto out;
+ *dest++ = '\\';
+ *dest++ = (c >> 6) + '0';
+ *dest++ = ((c >> 3) & 7) + '0';
+ *dest++ = (c & 7) + '0';
+ }
+ src++;
+ }
+
+ if (--dest_len <= 0)
+ goto out;
+ *dest = '\0';
+
+ return 0;
+out: ;
+ return -ENOMEM;
+}
+
+/* Get argv[0] of "struct linux_binprm". */
+static char *tmy_get_argv0(struct linux_binprm *bprm)
+{
+ char *arg_ptr;
+ int arg_len = 0;
+ unsigned long pos = bprm->p;
+ int i = pos / PAGE_SIZE;
+ int offset = pos % PAGE_SIZE;
+
+ if (bprm->argc <= 0)
+ return NULL;
+
+ arg_ptr = tmy_alloc(PAGE_SIZE);
+
+ if (!arg_ptr)
+ goto out;
+
+ while (1) {
+ struct page *page;
+ const char *kaddr;
+ char *tmp_arg;
+
+#ifdef CONFIG_MMU
+ if (get_user_pages(current, bprm->mm, pos,
+ 1, 0, 1, &page, NULL) <= 0)
+ goto out;
+#else
+ page = bprm->page[i];
+#endif
+ kaddr = kmap(page);
+ if (!kaddr) { /* Mapping failed. */
+#ifdef CONFIG_MMU
+ put_page(page);
+#endif
+ goto out;
+ }
+
+ memmove(arg_ptr + arg_len, kaddr + offset, PAGE_SIZE - offset);
+ kunmap(page);
+
+#ifdef CONFIG_MMU
+ put_page(page);
+ pos += PAGE_SIZE - offset;
+#endif
+
+ arg_len += PAGE_SIZE - offset;
+
+ if (memchr(arg_ptr, '\0', arg_len))
+ break;
+
+ tmp_arg = tmy_alloc(arg_len + PAGE_SIZE);
+ if (!tmp_arg)
+ goto out;
+
+ memmove(tmp_arg, arg_ptr, arg_len);
+ tmy_free(arg_ptr);
+ arg_ptr = tmp_arg;
+ i++;
+ offset = 0;
+ }
+ return arg_ptr;
+out: ;
+ tmy_free(arg_ptr);
+
+ return NULL;
+}
+
+/**
+ * tmy_find_next_domain - find a domain to transit to if do_execve() succeeds.
+ * @bprm: pointer to "struct linux_binprm".
+ * @next_domain: pointer to pointer to "struct domain_info".
+ *
+ * Returns zero if success. @next_domain receives new domain to transit to.
+ * Returns nonzero on failure.
+ *
+ * This function handles TOMOYO Linux's domain transition.
+ * New domains are automatically created unless the domain the caller process
+ * belongs to is assigned a profile for enforcing mode.
+ */
+int tmy_find_next_domain(struct linux_binprm *bprm,
+ struct domain_info **next_domain)
+{
+ /* This function assumes that the size of buffer returned */
+ /* by tmy_realpath() = TMY_MAX_PATHNAME_LEN. */
+ struct domain_info *old_domain = TMY_SECURITY->domain;
+ struct domain_info *domain = NULL;
+ const char *old_domain_name = old_domain->domainname->name;
+ const char *original_name = bprm->filename;
+ struct file *filp = bprm->file;
+ char *new_domain_name = NULL;
+ char *real_program_name = NULL;
+ char *symlink_program_name = NULL;
+ const u8 is_enforce = tmy_enforce(TMY_MAC_FOR_FILE);
+ int retval;
+ struct path_info r;
+ struct path_info s;
+ struct path_info l;
+
+ /*
+ * Built-in initializers.
+ * This is needed because policies are not loaded
+ * until starting /sbin/init .
+ */
+ static int first = 1;
+ if (first) {
+ tmy_add_domain_initializer_entry(NULL, "/sbin/hotplug", 0, 0);
+ tmy_add_domain_initializer_entry(NULL, "/sbin/modprobe", 0, 0);
+ tmy_add_domain_initializer_entry(NULL, "/sbin/udevd", 0, 0);
+ first = 0;
+ }
+
+ /* Get realpath of program. */
+ /* I hope tmy_realpath() won't fail with -ENOMEM. */
+ retval = -ENOENT;
+ real_program_name = tmy_realpath(original_name);
+
+ if (!real_program_name)
+ goto out;
+
+ /* Get realpath of symbolic link. */
+ symlink_program_name = tmy_realpath_nofollow(original_name);
+ if (!symlink_program_name)
+ goto out;
+
+ r.name = real_program_name;
+ tmy_fill_path_info(&r);
+ s.name = symlink_program_name;
+ tmy_fill_path_info(&s);
+ l.name = strrchr(old_domain_name, ' ');
+
+ if (l.name)
+ l.name++;
+ else
+ l.name = old_domain_name;
+ tmy_fill_path_info(&l);
+
+ /* Check 'alias' directive. */
+ if (tmy_pathcmp(&r, &s)) {
+ struct alias_entry *ptr;
+
+ /* Is this program allowed to be called via symbolic links? */
+ for (ptr = alias_list; ptr; ptr = ptr->next) {
+ if (ptr->is_deleted ||
+ tmy_pathcmp(&r, ptr->original_name) ||
+ tmy_pathcmp(&s, ptr->aliased_name))
+ continue;
+ memset(real_program_name, 0, TMY_MAX_PATHNAME_LEN);
+ strncpy(real_program_name,
+ ptr->aliased_name->name,
+ TMY_MAX_PATHNAME_LEN - 1);
+ tmy_fill_path_info(&r);
+ break;
+ }
+ }
+
+ /* Compare basename of real_program_name and argv[0] */
+ if (bprm->argc > 0 && tmy_flags(TMY_MAC_FOR_ARGV0)) {
+
+ char *org_argv0 = tmy_get_argv0(bprm);
+
+ retval = -ENOMEM;
+ if (org_argv0) {
+
+ const int len = strlen(org_argv0);
+ char *printable_argv0 = tmy_alloc(len * 4 + 8);
+
+ if (printable_argv0 &&
+ !tmy_escape(printable_argv0, org_argv0,
+ len * 4 + 8)) {
+ const char *base_argv0;
+ const char *base_filename;
+
+ base_argv0 = strrchr(printable_argv0, '/');
+ if (!base_argv0)
+ base_argv0 = printable_argv0;
+ else
+ base_argv0++;
+
+ base_filename = strrchr(real_program_name, '/');
+ if (!base_filename)
+ base_filename = real_program_name;
+ else
+ base_filename++;
+
+ if (strcmp(base_argv0, base_filename))
+ retval = tmy_argv0_perm(&r, base_argv0);
+ else
+ retval = 0;
+ }
+
+ tmy_free(printable_argv0);
+ tmy_free(org_argv0);
+ }
+
+ if (retval)
+ goto out;
+
+ }
+
+
+ /* Check 'aggregator' directive. */
+ {
+ struct aggregator_entry *ptr;
+
+ /* Is this program allowed to be aggregated? */
+ for (ptr = aggregator_list; ptr; ptr = ptr->next) {
+ if (ptr->is_deleted ||
+ !tmy_path_match(&r, ptr->original_name))
+ continue;
+ memset(real_program_name, 0, TMY_MAX_PATHNAME_LEN);
+ strncpy(real_program_name,
+ ptr->aggregated_name->name,
+ TMY_MAX_PATHNAME_LEN - 1);
+ tmy_fill_path_info(&r);
+ break;
+ }
+ }
+
+ /* Check execute permission. */
+ retval = tmy_exec_perm(&r, filp);
+ if (retval < 0)
+ goto out;
+
+ /* Allocate memory for calcurating domain name. */
+ retval = -ENOMEM;
+ new_domain_name = tmy_alloc(TMY_MAX_PATHNAME_LEN + 16);
+ if (!new_domain_name)
+ goto out;
+
+ if (tmy_is_domain_initializer(old_domain->domainname, &r, &l))
+ /* Transit to the child of KERNEL_DOMAIN domain. */
+ snprintf(new_domain_name, TMY_MAX_PATHNAME_LEN + 1,
+ TMY_ROOT_NAME " " "%s", real_program_name);
+ else if (old_domain == &KERNEL_DOMAIN && !sbin_init_started)
+ /*
+ * Needn't to transit from kernel domain
+ * before starting /sbin/init .
+ * But transit from kernel domain if executing initializers,
+ * for they might start before /sbin/init .
+ */
+ domain = old_domain;
+ else if (tmy_is_domain_keeper(old_domain->domainname, &r, &l))
+ /* Keep current domain. */
+ domain = old_domain;
+ else
+ /* Normal domain transition. */
+ snprintf(new_domain_name,
+ TMY_MAX_PATHNAME_LEN + 1,
+ "%s %s",
+ old_domain_name,
+ real_program_name);
+
+ if (domain || strlen(new_domain_name) >= TMY_MAX_PATHNAME_LEN)
+ goto ok;
+
+ if (is_enforce) {
+ domain = tmy_find_domain(new_domain_name);
+ if (!domain &&
+ tmy_supervisor("#Need to create domain\n%s\n",
+ new_domain_name) == 0) {
+ const u8 profile = TMY_SECURITY->domain->profile;
+ domain = tmy_new_domain(new_domain_name, profile);
+ }
+ } else {
+ const u8 profile = TMY_SECURITY->domain->profile;
+ domain = tmy_new_domain(new_domain_name, profile);
+ }
+
+ok: ;
+
+ if (!domain) {
+ printk(KERN_INFO "TOMOYO-ERROR: Domain '%s' not defined.\n",
+ new_domain_name);
+ if (is_enforce)
+ retval = -EPERM;
+ } else
+ retval = 0;
+out: ;
+
+ tmy_free(new_domain_name);
+ tmy_free(real_program_name);
+ tmy_free(symlink_program_name);
+ *next_domain = domain ? domain : old_domain;
+
+ return retval;
+}