Commit eadd99cc authored by Tetsuo Handa's avatar Tetsuo Handa Committed by James Morris
Browse files

TOMOYO: Add auditing interface.



Add /sys/kernel/security/tomoyo/audit interface. This interface generates audit
logs in the form of domain policy so that /usr/sbin/tomoyo-auditd can reuse
audit logs for appending to /sys/kernel/security/tomoyo/domain_policy
interface.
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent d5ca1725
obj-y = common.o domain.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
obj-y = audit.o common.o domain.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
/*
* security/tomoyo/audit.c
*
* Pathname restriction functions.
*
* Copyright (C) 2005-2010 NTT DATA CORPORATION
*/
#include "common.h"
#include <linux/slab.h>
/**
* tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
*
* @time: Seconds since 1970/01/01 00:00:00.
* @stamp: Pointer to "struct tomoyo_time".
*
* Returns nothing.
*
* This function does not handle Y2038 problem.
*/
static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
{
static const u16 tomoyo_eom[2][12] = {
{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
};
u16 y;
u8 m;
bool r;
stamp->sec = time % 60;
time /= 60;
stamp->min = time % 60;
time /= 60;
stamp->hour = time % 24;
time /= 24;
for (y = 1970; ; y++) {
const unsigned short days = (y & 3) ? 365 : 366;
if (time < days)
break;
time -= days;
}
r = (y & 3) == 0;
for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
;
if (m)
time -= tomoyo_eom[r][m - 1];
stamp->year = y;
stamp->month = ++m;
stamp->day = ++time;
}
/**
* tomoyo_print_header - Get header line of audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
*
* Returns string representation.
*
* This function uses kmalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
struct tomoyo_time stamp;
const pid_t gpid = task_pid_nr(current);
static const int tomoyo_buffer_len = 4096;
char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
pid_t ppid;
if (!buffer)
return NULL;
{
struct timeval tv;
do_gettimeofday(&tv);
tomoyo_convert_time(tv.tv_sec, &stamp);
}
rcu_read_lock();
ppid = task_tgid_vnr(current->real_parent);
rcu_read_unlock();
snprintf(buffer, tomoyo_buffer_len - 1,
"#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
"granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
"uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
"fsuid=%u fsgid=%u }",
stamp.year, stamp.month, stamp.day, stamp.hour,
stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode],
tomoyo_yesno(r->granted), gpid, task_tgid_vnr(current), ppid,
current_uid(), current_gid(), current_euid(), current_egid(),
current_suid(), current_sgid(), current_fsuid(),
current_fsgid());
return buffer;
}
/**
* tomoyo_init_log - Allocate buffer for audit logs.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns pointer to allocated memory.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf = NULL;
const char *header = NULL;
int pos;
const char *domainname = tomoyo_domain()->domainname->name;
header = tomoyo_print_header(r);
if (!header)
return NULL;
/* +10 is for '\n' etc. and '\0'. */
len += strlen(domainname) + strlen(header) + 10;
len = tomoyo_round2(len);
buf = kzalloc(len, GFP_NOFS);
if (!buf)
goto out;
len--;
pos = snprintf(buf, len, "%s", header);
pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
vsnprintf(buf + pos, len - pos, fmt, args);
out:
kfree(header);
return buf;
}
/* Wait queue for /sys/kernel/security/tomoyo/audit. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
/* Structure for audit log. */
struct tomoyo_log {
struct list_head list;
char *log;
int size;
};
/* The list for "struct tomoyo_log". */
static LIST_HEAD(tomoyo_log);
/* Lock for "struct list_head tomoyo_log". */
static DEFINE_SPINLOCK(tomoyo_log_lock);
/* Length of "stuct list_head tomoyo_log". */
static unsigned int tomoyo_log_count;
/**
* tomoyo_get_audit - Get audit mode.
*
* @profile: Profile number.
* @index: Index number of functionality.
* @is_granted: True if granted log, false otherwise.
*
* Returns true if this request should be audited, false otherwise.
*/
static bool tomoyo_get_audit(const u8 profile, const u8 index,
const bool is_granted)
{
u8 mode;
const u8 category = TOMOYO_MAC_CATEGORY_FILE + TOMOYO_MAX_MAC_INDEX;
struct tomoyo_profile *p;
if (!tomoyo_policy_loaded)
return false;
p = tomoyo_profile(profile);
if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
return false;
mode = p->config[index];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->config[category];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
mode = p->default_config;
if (is_granted)
return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
}
/**
* tomoyo_write_log2 - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @len: Buffer size needed for @fmt and @args.
* @fmt: The printf()'s format string.
* @args: va_list structure for @fmt.
*
* Returns nothing.
*/
void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
va_list args)
{
char *buf;
struct tomoyo_log *entry;
bool quota_exceeded = false;
if (!tomoyo_get_audit(r->profile, r->type, r->granted))
goto out;
buf = tomoyo_init_log(r, len, fmt, args);
if (!buf)
goto out;
entry = kzalloc(sizeof(*entry), GFP_NOFS);
if (!entry) {
kfree(buf);
goto out;
}
entry->log = buf;
len = tomoyo_round2(strlen(buf) + 1);
/*
* The entry->size is used for memory quota checks.
* Don't go beyond strlen(entry->log).
*/
entry->size = len + tomoyo_round2(sizeof(*entry));
spin_lock(&tomoyo_log_lock);
if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
quota_exceeded = true;
} else {
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
list_add_tail(&entry->list, &tomoyo_log);
tomoyo_log_count++;
}
spin_unlock(&tomoyo_log_lock);
if (quota_exceeded) {
kfree(buf);
kfree(entry);
goto out;
}
wake_up(&tomoyo_log_wait);
out:
return;
}
/**
* tomoyo_write_log - Write an audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
* @fmt: The printf()'s format string, followed by parameters.
*
* Returns nothing.
*/
void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
{
va_list args;
int len;
va_start(args, fmt);
len = vsnprintf((char *) &len, 1, fmt, args) + 1;
va_end(args);
va_start(args, fmt);
tomoyo_write_log2(r, len, fmt, args);
va_end(args);
}
/**
* tomoyo_read_log - Read an audit log.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns nothing.
*/
void tomoyo_read_log(struct tomoyo_io_buffer *head)
{
struct tomoyo_log *ptr = NULL;
if (head->r.w_pos)
return;
kfree(head->read_buf);
head->read_buf = NULL;
spin_lock(&tomoyo_log_lock);
if (!list_empty(&tomoyo_log)) {
ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
list_del(&ptr->list);
tomoyo_log_count--;
tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
}
spin_unlock(&tomoyo_log_lock);
if (ptr) {
head->read_buf = ptr->log;
head->r.w[head->r.w_pos++] = head->read_buf;
kfree(ptr);
}
}
/**
* tomoyo_poll_log - Wait for an audit log.
*
* @file: Pointer to "struct file".
* @wait: Pointer to "poll_table".
*
* Returns POLLIN | POLLRDNORM when ready to read an audit log.
*/
int tomoyo_poll_log(struct file *file, poll_table *wait)
{
if (tomoyo_log_count)
return POLLIN | POLLRDNORM;
poll_wait(file, &tomoyo_log_wait, wait);
if (tomoyo_log_count)
return POLLIN | POLLRDNORM;
return 0;
}
......@@ -17,9 +17,12 @@ static unsigned int tomoyo_profile_version;
/* Profile table. Memory is allocated as needed. */
static struct tomoyo_profile *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
/* String table for functionality that takes 4 modes. */
static const char *tomoyo_mode[4] = {
"disabled", "learning", "permissive", "enforcing"
/* String table for operation mode. */
const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE] = {
[TOMOYO_CONFIG_DISABLED] = "disabled",
[TOMOYO_CONFIG_LEARNING] = "learning",
[TOMOYO_CONFIG_PERMISSIVE] = "permissive",
[TOMOYO_CONFIG_ENFORCING] = "enforcing"
};
/* String table for /sys/kernel/security/tomoyo/profile */
......@@ -53,6 +56,7 @@ static const char *tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
/* String table for PREFERENCE keyword. */
static const char * const tomoyo_pref_keywords[TOMOYO_MAX_PREF] = {
[TOMOYO_PREF_MAX_AUDIT_LOG] = "max_audit_log",
[TOMOYO_PREF_MAX_LEARNING_ENTRY] = "max_learning_entry",
};
......@@ -66,12 +70,10 @@ static bool tomoyo_manage_by_non_root;
*
* @value: Bool value.
*/
/*
static const char *tomoyo_yesno(const unsigned int value)
const char *tomoyo_yesno(const unsigned int value)
{
return value ? "yes" : "no";
}
*/
/**
* tomoyo_addprintf - strncat()-like-snprintf().
......@@ -117,7 +119,7 @@ static bool tomoyo_flush(struct tomoyo_io_buffer *head)
head->r.w[0] = w;
if (*w)
return false;
/* Add '\0' for query. */
/* Add '\0' for audit logs and query. */
if (head->poll) {
if (!head->read_user_buf_avail ||
copy_to_user(head->read_user_buf, "", 1))
......@@ -300,9 +302,12 @@ static struct tomoyo_profile *tomoyo_assign_profile(const unsigned int profile)
ptr = tomoyo_profile_ptr[profile];
if (!ptr && tomoyo_memory_ok(entry)) {
ptr = entry;
ptr->default_config = TOMOYO_CONFIG_DISABLED;
ptr->default_config = TOMOYO_CONFIG_DISABLED |
TOMOYO_CONFIG_WANT_GRANT_LOG |
TOMOYO_CONFIG_WANT_REJECT_LOG;
memset(ptr->config, TOMOYO_CONFIG_USE_DEFAULT,
sizeof(ptr->config));
ptr->pref[TOMOYO_PREF_MAX_AUDIT_LOG] = 1024;
ptr->pref[TOMOYO_PREF_MAX_LEARNING_ENTRY] = 2048;
mb(); /* Avoid out-of-order execution. */
tomoyo_profile_ptr[profile] = ptr;
......@@ -338,7 +343,6 @@ struct tomoyo_profile *tomoyo_profile(const u8 profile)
*
* Returns 1 if "@find=yes" was found, 0 if "@find=no" was found, -1 otherwise.
*/
/*
static s8 tomoyo_find_yesno(const char *string, const char *find)
{
const char *cp = strstr(string, find);
......@@ -351,7 +355,6 @@ static s8 tomoyo_find_yesno(const char *string, const char *find)
}
return -1;
}
*/
/**
* tomoyo_set_uint - Set value for specified preference.
......@@ -412,6 +415,24 @@ static int tomoyo_set_mode(char *name, const char *value,
* 'config' from 'TOMOYO_CONFIG_USE_DEAFULT'.
*/
config = (config & ~7) | mode;
if (config != TOMOYO_CONFIG_USE_DEFAULT) {
switch (tomoyo_find_yesno(value, "grant_log")) {
case 1:
config |= TOMOYO_CONFIG_WANT_GRANT_LOG;
break;
case 0:
config &= ~TOMOYO_CONFIG_WANT_GRANT_LOG;
break;
}
switch (tomoyo_find_yesno(value, "reject_log")) {
case 1:
config |= TOMOYO_CONFIG_WANT_REJECT_LOG;
break;
case 0:
config &= ~TOMOYO_CONFIG_WANT_REJECT_LOG;
break;
}
}
}
if (i < TOMOYO_MAX_MAC_INDEX + TOMOYO_MAX_MAC_CATEGORY_INDEX)
profile->config[i] = config;
......@@ -469,15 +490,30 @@ static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
return tomoyo_set_mode(data, cp, profile);
}
/**
* tomoyo_print_config - Print mode for specified functionality.
*
* @head: Pointer to "struct tomoyo_io_buffer".
* @config: Mode for that functionality.
*
* Returns nothing.
*
* Caller prints functionality's name.
*/
static void tomoyo_print_config(struct tomoyo_io_buffer *head, const u8 config)
{
tomoyo_io_printf(head, "={ mode=%s }\n", tomoyo_mode[config & 3]);
tomoyo_io_printf(head, "={ mode=%s grant_log=%s reject_log=%s }\n",
tomoyo_mode[config & 3],
tomoyo_yesno(config & TOMOYO_CONFIG_WANT_GRANT_LOG),
tomoyo_yesno(config & TOMOYO_CONFIG_WANT_REJECT_LOG));
}
/**
* tomoyo_read_profile - Read profile table.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns nothing.
*/
static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
{
......@@ -488,7 +524,7 @@ static void tomoyo_read_profile(struct tomoyo_io_buffer *head)
profile = tomoyo_profile_ptr[index];
switch (head->r.step) {
case 0:
tomoyo_io_printf(head, "PROFILE_VERSION=%s\n", "20090903");
tomoyo_io_printf(head, "PROFILE_VERSION=%u\n", 20090903);
head->r.step++;
break;
case 1:
......@@ -1359,103 +1395,68 @@ static void tomoyo_read_exception(struct tomoyo_io_buffer *head)
head->r.eof = true;
}
/**
* tomoyo_print_header - Get header line of audit log.
*
* @r: Pointer to "struct tomoyo_request_info".
*
* Returns string representation.
*
* This function uses kmalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
struct timeval tv;
const pid_t gpid = task_pid_nr(current);
static const int tomoyo_buffer_len = 4096;
char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
pid_t ppid;
if (!buffer)
return NULL;
do_gettimeofday(&tv);
rcu_read_lock();
ppid = task_tgid_vnr(current->real_parent);
rcu_read_unlock();
snprintf(buffer, tomoyo_buffer_len - 1,
"#timestamp=%lu profile=%u mode=%s (global-pid=%u)"
" task={ pid=%u ppid=%u uid=%u gid=%u euid=%u"
" egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }",
tv.tv_sec, r->profile, tomoyo_mode[r->mode], gpid,
task_tgid_vnr(current), ppid,
current_uid(), current_gid(), current_euid(),
current_egid(), current_suid(), current_sgid(),
current_fsuid(), current_fsgid());
return buffer;
}
/**
* tomoyo_init_audit_log - Allocate buffer for audit logs.
*
* @len: Required size.
* @r: Pointer to "struct tomoyo_request_info".
*
* Returns pointer to allocated memory.
*
* The @len is updated to add the header lines' size on success.
*
* This function uses kzalloc(), so caller must kfree() if this function
* didn't return NULL.
*/
static char *tomoyo_init_audit_log(int *len, struct tomoyo_request_info *r)
{
char *buf = NULL;
const char *header;
const char *domainname;
if (!r->domain)
r->domain = tomoyo_domain();
domainname = r->domain->domainname->name;
header = tomoyo_print_header(r);
if (!header)
return NULL;
*len += strlen(domainname) + strlen(header) + 10;
buf = kzalloc(*len, GFP_NOFS);
if (buf)
snprintf(buf, (*len) - 1, "%s\n%s\n", header, domainname);
kfree(header);
return buf;
}
/* Wait queue for tomoyo_query_list. */
/* Wait queue for kernel -> userspace notification. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_query_wait);
/* Lock for manipulating tomoyo_query_list. */
static DEFINE_SPINLOCK(tomoyo_query_list_lock);
/* Wait queue for userspace -> kernel notification. */
static DECLARE_WAIT_QUEUE_HEAD(tomoyo_answer_wait);
/* Structure for query. */
struct tomoyo_query {
struct list_head list;
char *query;
int query_len;
size_t query_len;
unsigned int serial;
int timer;
int answer;
u8 timer;
u8 answer;
u8 retry;
};
/* The list for "struct tomoyo_query". */
static LIST_HEAD(tomoyo_query_list);
/* Lock for manipulating tomoyo_query_list. */
static DEFINE_SPINLOCK(tomoyo_query_list_lock);
/*
* Number of "struct file" referring /sys/kernel/security/tomoyo/query
* interface.
*/
static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
/**
* tomoyo_add_entry - Add an ACL to current thread's domain. Used by learning mode.
*
* @domain: Pointer to "struct tomoyo_domain_info".
* @header: Lines containing ACL.
*
* Returns nothing.
*/
static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
{
char *buffer;
char *cp = strchr(header, '\n');
int len;
if (!cp)
return;
cp = strchr(cp + 1, '\n');
if (!cp)
return;
*cp++ = '\0';
len = strlen(cp) + 1;
buffer = kmalloc(len, GFP_NOFS);
if (!buffer)
return;
snprintf(buffer, len - 1, "%s", cp);
tomoyo_normalize_line(buffer);
tomoyo_write_domain2(&domain->acl_info_list, buffer, false);
kfree(buffer);
}
/**
* tomoyo_supervisor - Ask for the supervisor's decision.
*
* @r: Pointer to "struct tomoyo_request_info".
* @fmt: The printf()'s format string, followed by parameters.
* @r: Pointer to "struct tomoyo_request_info".
* @fmt: The printf()'s format string, followed by parameters.
*
* Returns 0 if the supervisor decided to permit the access request which
* violated the policy in enforcing mode, TOMOYO_RETRY_REQUEST if the
......@@ -1465,88 +1466,77 @@ static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
{
va_list args;
int error = -EPERM;
int pos;
int error;
int len;
static unsigned int tomoyo_serial;
struct tomoyo_query *entry = NULL;
struct tomoyo_query entry = { };
bool quota_exceeded = false;
char *header;
va_start(args, fmt);
len = vsnprintf((char *) &len, 1, fmt, args) + 1;
va_end(args);
/* Write /sys/kernel/security/tomoyo/audit. */
va_start(args, fmt);
tomoyo_write_log2(r, len, fmt, args);
va_end(args);
/* Nothing more to do if granted. */
if (r->granted)
return 0;
switch (r->mode) {
char *buffer;
case TOMOYO_CONFIG_ENFORCING:
error = -EPERM;
if (atomic_read(&tomoyo_query_observers))
break;
goto out;
case TOMOYO_CONFIG_LEARNING:
if (!tomoyo_domain_quota_is_ok(r))
return 0;
va_start(args, fmt);
len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 4;
va_end(args);
buffer = kmalloc(len, GFP_NOFS);
if (!buffer)