security/ccsecurity/util.c

/*
 * fs/ccs_common.c
 *
 * Common functions for SAKURA and TOMOYO.
 *
 * Copyright (C) 2005-2007  NTT DATA CORPORATION
 *
 * Version: 1.5.0-pre   2007/08/06
 *
 * This file is applicable to both 2.4.30 and 2.6.11 and later.
 * See README.ccs for ChangeLog.
 *
 */

#include <linux/string.h>
#include <linux/mm.h>
#include <linux/utime.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <stdarg.h>
#include <linux/version.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
#include <linux/namei.h>
#include <linux/mount.h>
static const int lookup_flags = LOOKUP_FOLLOW;
#else
static const int lookup_flags = LOOKUP_FOLLOW | LOOKUP_POSITIVE;
#endif
#include <linux/version.h>
#include <linux/realpath.h>
#include <linux/ccs_common.h>
#include <linux/ccs_proc.h>
#include <linux/tomoyo.h>

#ifdef CONFIG_TOMOYO_MAX_ACCEPT_ENTRY
#define MAX_ACCEPT_ENTRY (CONFIG_TOMOYO_MAX_ACCEPT_ENTRY)
#else
#define MAX_ACCEPT_ENTRY 2048
#endif
#ifdef CONFIG_TOMOYO_MAX_GRANT_LOG
#define MAX_GRANT_LOG (CONFIG_TOMOYO_MAX_GRANT_LOG)
#else
#define MAX_GRANT_LOG 1024
#endif
#ifdef CONFIG_TOMOYO_MAX_REJECT_LOG
#define MAX_REJECT_LOG (CONFIG_TOMOYO_MAX_REJECT_LOG)
#else
#define MAX_REJECT_LOG 1024
#endif

/*************************  VARIABLES  *************************/

/* /sbin/init started? */
int sbin_init_started = 0;

const char *ccs_log_level = KERN_DEBUG;

static struct {
        const char *keyword;
        unsigned int current_value;
        const unsigned int max_value;
} ccs_control_array[CCS_MAX_CONTROL_INDEX] = {
        [CCS_PROFILE_COMMENT]            = { "COMMENT",             0, 0 }, /* Reserved for string. */
        [CCS_TOMOYO_MAC_FOR_FILE]        = { "MAC_FOR_FILE",        0, 3 },
        [CCS_TOMOYO_MAC_FOR_ARGV0]       = { "MAC_FOR_ARGV0",       0, 3 },
        [CCS_TOMOYO_MAC_FOR_NETWORK]     = { "MAC_FOR_NETWORK",     0, 3 },
        [CCS_TOMOYO_MAC_FOR_SIGNAL]      = { "MAC_FOR_SIGNAL",      0, 3 },
        [CCS_SAKURA_DENY_CONCEAL_MOUNT]  = { "DENY_CONCEAL_MOUNT",  0, 3 },
        [CCS_SAKURA_RESTRICT_CHROOT]     = { "RESTRICT_CHROOT",     0, 3 },
        [CCS_SAKURA_RESTRICT_MOUNT]      = { "RESTRICT_MOUNT",      0, 3 },
        [CCS_SAKURA_RESTRICT_UNMOUNT]    = { "RESTRICT_UNMOUNT",    0, 3 },
        [CCS_SAKURA_RESTRICT_PIVOT_ROOT] = { "RESTRICT_PIVOT_ROOT", 0, 3 },
        [CCS_SAKURA_RESTRICT_AUTOBIND]   = { "RESTRICT_AUTOBIND",   0, 1 },
        [CCS_TOMOYO_MAX_ACCEPT_ENTRY]    = { "MAX_ACCEPT_ENTRY",    MAX_ACCEPT_ENTRY, INT_MAX },
        [CCS_TOMOYO_MAX_GRANT_LOG]       = { "MAX_GRANT_LOG",       MAX_GRANT_LOG, INT_MAX },
        [CCS_TOMOYO_MAX_REJECT_LOG]      = { "MAX_REJECT_LOG",      MAX_REJECT_LOG, INT_MAX },
        [CCS_TOMOYO_VERBOSE]             = { "TOMOYO_VERBOSE",      1, 1 },
        [CCS_ALLOW_ENFORCE_GRACE]        = { "ALLOW_ENFORCE_GRACE", 0, 1 },
};

struct profile {
        unsigned int value[CCS_MAX_CONTROL_INDEX];
        const struct path_info *comment;
};

static struct profile *profile_ptr[MAX_PROFILES];

/*************************  UTILITY FUNCTIONS  *************************/

#ifdef CONFIG_TOMOYO
static int __init TOMOYO_Quiet_Setup(char *str)
{
        ccs_control_array[CCS_TOMOYO_VERBOSE].current_value = 0;
        return 0;
}

__setup("TOMOYO_QUIET", TOMOYO_Quiet_Setup);
#endif

/* Am I root? */
static int isRoot(void)
{
        return !current->uid && !current->euid;
}

/*
 * Format string.
 * Leading and trailing whitespaces are removed.
 * Multiple whitespaces are packed into single space.
 */
static void NormalizeLine(unsigned char *buffer)
{
        unsigned char *sp = buffer, *dp = buffer;
        int first = 1;
        while (*sp && (*sp <= ' ' || *sp >= 127)) sp++;
        while (*sp) {
                if (!first) *dp++ = ' ';
                first = 0;
                while (*sp > ' ' && *sp < 127) *dp++ = *sp++;
                while (*sp && (*sp <= ' ' || *sp >= 127)) sp++;
        }
        *dp = '\0';
}

/*
 *  Check whether the given filename follows the naming rules.
 *  Returns nonzero if follows, zero otherwise.
 */
int IsCorrectPath(const char *filename, const int start_type, const int pattern_type, const int end_type, const char *function)
{
        int contains_pattern = 0;
        char c, d, e;
        const char *original_filename = filename;
        if (!filename) goto out;
        c = *filename;
        if (start_type == 1) { /* Must start with '/' */
                if (c != '/') goto out;
        } else if (start_type == -1) { /* Must not start with '/' */
                if (c == '/') goto out;
        }
        if (c) c = * (strchr(filename, '\0') - 1);
        if (end_type == 1) { /* Must end with '/' */
                if (c != '/') goto out;
        } else if (end_type == -1) { /* Must not end with '/' */
                if (c == '/') goto out;
        }
        while ((c = *filename++) != '\0') {
                if (c == '\\') {
                        switch ((c = *filename++)) {
                        case '\\':  /* "\\" */
                                continue;
                        case '$':   /* "\$" */
                        case '+':   /* "\+" */
                        case '?':   /* "\?" */
                        case '*':   /* "\*" */
                        case '@':   /* "\@" */
                        case 'x':   /* "\x" */
                        case 'X':   /* "\X" */
                        case 'a':   /* "\a" */
                        case 'A':   /* "\A" */
                        case '-':   /* "\-" */
                                if (pattern_type == -1) break; /* Must not contain pattern */
                                contains_pattern = 1;
                                continue;
                        case '0':   /* "\ooo" */
                        case '1':
                        case '2':
                        case '3':
                                if ((d = *filename++) >= '0' && d <= '7' && (e = *filename++) >= '0' && e <= '7') {
                                        const unsigned char f =
                                                (((unsigned char) (c - '0')) << 6) +
                                                (((unsigned char) (d - '0')) << 3) +
                                                (((unsigned char) (e - '0')));
                                        if (f && (f <= ' ' || f >= 127)) continue; /* pattern is not \000 */
                                }
                        }
                        goto out;
                } else if (c <= ' ' || c >= 127) {
                        goto out;
                }
        }
        if (pattern_type == 1) { /* Must contain pattern */
                if (!contains_pattern) goto out;
        }
        return 1;
 out:
        printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function, original_filename);
        return 0;
}

/*
 *  Check whether the given domainname follows the naming rules.
 *  Returns nonzero if follows, zero otherwise.
 */
int IsCorrectDomain(const unsigned char *domainname, const char *function)
{
        unsigned char c, d, e;
        const char *org_domainname = domainname;
        if (!domainname || strncmp(domainname, ROOT_NAME, ROOT_NAME_LEN)) goto out;
        domainname += ROOT_NAME_LEN;
        if (!*domainname) return 1;
        do {
                if (*domainname++ != ' ') goto out;
                if (*domainname++ != '/') goto out;
                while ((c = *domainname) != '\0' && c != ' ') {
                        domainname++;
                        if (c == '\\') {
                                switch ((c = *domainname++)) {
                                case '\\':  /* "\\" */
                                        continue;
                                case '0':   /* "\ooo" */
                                case '1':
                                case '2':
                                case '3':
                                        if ((d = *domainname++) >= '0' && d <= '7' && (e = *domainname++) >= '0' && e <= '7') {
                                                const unsigned char f =
                                                        (((unsigned char) (c - '0')) << 6) +
                                                        (((unsigned char) (d - '0')) << 3) +
                                                        (((unsigned char) (e - '0')));
                                                if (f && (f <= ' ' || f >= 127)) continue; /* pattern is not \000 */
                                        }
                                }
                                goto out;
                        } else if (c < ' ' || c >= 127) {
                                goto out;
                        }
                }
        } while (*domainname);
        return 1;
 out:
        printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function, org_domainname);
        return 0;
}

static int PathDepth(const char *pathname)
{
        int i = 0;
        if (pathname) {
                char *ep = strchr(pathname, '\0');
                if (pathname < ep--) {
                        if (*ep != '/') i++;
                        while (pathname <= ep) if (*ep-- == '/') i += 2;
                }
        }
        return i;
}

static int const_part_length(const char *filename)
{
        int len = 0;
        if (filename) {
                char c;
                while ((c = *filename++) != '\0') {
                        if (c != '\\') { len++; continue; }
                        switch (c = *filename++) {
                        case '\\':  /* "\\" */
                                len += 2; continue;
                        case '0':   /* "\ooo" */
                        case '1':
                        case '2':
                        case '3':
                                if ((c = *filename++) >= '0' && c <= '7' && (c = *filename++) >= '0' && c <= '7') { len += 4; continue; }
                        }
                        break;
                }
        }
        return len;
}

void fill_path_info(struct path_info *ptr)
{
        const char *name = ptr->name;
        const int len = strlen(name);
        ptr->total_len = len;
        ptr->const_len = const_part_length(name);
        ptr->is_dir = len && (name[len - 1] == '/');
        ptr->is_patterned = (ptr->const_len < len);
        ptr->hash = full_name_hash(name, len);
        ptr->depth = PathDepth(name);
}

static int FileMatchesToPattern2(const char *filename, const char *filename_end, const char *pattern, const char *pattern_end)
{
        while (filename < filename_end && pattern < pattern_end) {
                if (*pattern != '\\') {
                        if (*filename++ != *pattern++) return 0;
                } else {
                        char c = *filename;
                        pattern++;
                        switch (*pattern) {
                        case '?':
                                if (c == '/') {
                                        return 0;
                                } else if (c == '\\') {
                                        if ((c = filename[1]) == '\\') {
                                                filename++; /* safe because filename is \\ */
                                        } else if (c >= '0' && c <= '3' && (c = filename[2]) >= '0' && c <= '7' && (c = filename[3]) >= '0' && c <= '7') {
                                                filename += 3; /* safe because filename is \ooo */
                                        } else {
                                                return 0;
                                        }
                                }
                                break;
                        case '\\':
                                if (c != '\\') return 0;
                                if (*++filename != '\\') return 0; /* safe because *filename != '\0' */
                                break;
                        case '+':
                                if (c < '0' || c > '9') return 0;
                                break;
                        case 'x':
                                if (!((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f'))) return 0;
                                break;
                        case 'a':
                                if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'))) return 0;
                                break;
                        case '0':
                        case '1':
                        case '2':
                        case '3':
                                if (c == '\\' && (c = filename[1]) >= '0' && c <= '3' && c == *pattern
                                        && (c = filename[2]) >= '0' && c <= '7' && c == pattern[1]
                                        && (c = filename[3]) >= '0' && c <= '7' && c == pattern[2]) {
                                        filename += 3; /* safe because filename is \ooo */
                                        pattern += 2; /* safe because pattern is \ooo  */
                                        break;
                                }
                                return 0; /* Not matched. */
                        case '*':
                        case '@':
                                {
                                        int i;
                                        for (i = 0; i <= filename_end - filename; i++) {
                                                if (FileMatchesToPattern2(filename + i, filename_end, pattern + 1, pattern_end)) return 1;
                                                if ((c = filename[i]) == '.' && *pattern == '@') break;
                                                if (c == '\\') {
                                                        if ((c = filename[i + 1]) == '\\') {
                                                                i++; /* safe because filename is \\ */
                                                        } else if (c >= '0' && c <= '3' && (c = filename[i + 2]) >= '0' && c <= '7' && (c = filename[i + 3]) >= '0' && c <= '7') {
                                                                i += 3; /* safe because filename is \ooo */
                                                        } else {
                                                                break; /* Bad pattern. */
                                                        }
                                                }
                                        }
                                        return 0; /* Not matched. */
                                }
                        default:
                                {
                                        int i, j = 0;
                                        if ((c = *pattern) == '$') {
                                                while ((c = filename[j]) >= '0' && c <= '9') j++;
                                        } else if (c == 'X') {
                                                while (((c = filename[j]) >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f')) j++;
                                        } else if (c == 'A') {
                                                while (((c = filename[j]) >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) j++;
                                        }
                                        for (i = 1; i <= j; i++) {
                                                if (FileMatchesToPattern2(filename + i, filename_end, pattern + 1, pattern_end)) return 1;
                                        }
                                }
                                return 0; /* Not matched or bad pattern. */
                        }
                        filename++; /* safe because *filename != '\0' */
                        pattern++; /* safe because *pattern != '\0' */
                }
        }
        while (*pattern == '\\' && (*(pattern + 1) == '*' || *(pattern + 1) == '@')) pattern += 2;
        return (filename == filename_end && pattern == pattern_end);
}

static int FileMatchesToPattern(const char *filename, const char *filename_end, const char *pattern, const char *pattern_end)
{
        const char *pattern_start = pattern;
        int first = 1;
        int result;
        while (pattern < pattern_end - 1) {
                if (*pattern++ != '\\' || *pattern++ != '-') continue;
                result = FileMatchesToPattern2(filename, filename_end, pattern_start, pattern - 2);
                if (first) result = !result;
                if (result) return 0;
                first = 0;
                pattern_start = pattern;
        }
        result = FileMatchesToPattern2(filename, filename_end, pattern_start, pattern_end);
        return first ? result : !result;
}

/*
 *  Check whether the given pathname matches to the given pattern.
 *  Returns nonzero if matches, zero otherwise.
 *
 *  The following patterns are available.
 *    \\     \ itself.
 *    \ooo   Octal representation of a byte.
 *    \*     More than or equals to 0 character other than '/'.
 *    \@     More than or equals to 0 character other than '/' or '.'.
 *    \?     1 byte character other than '/'.
 *    \$     More than or equals to 1 decimal digit.
 *    \+     1 decimal digit.
 *    \X     More than or equals to 1 hexadecimal digit.
 *    \x     1 hexadecimal digit.
 *    \A     More than or equals to 1 alphabet character.
 *    \a     1 alphabet character.
 *    \-     Subtraction operator.
 */

int PathMatchesToPattern(const struct path_info *pathname0, const struct path_info *pattern0)
{
        /* if (!pathname || !pattern) return 0; */
        const char *pathname = pathname0->name, *pattern = pattern0->name;
        const int len = pattern0->const_len;
        if (!pattern0->is_patterned) return !pathcmp(pathname0, pattern0);
        if (pathname0->depth != pattern0->depth) return 0;
        if (strncmp(pathname, pattern, len)) return 0;
        pathname += len; pattern += len;
        while (*pathname && *pattern) {
                const char *pathname_delimiter = strchr(pathname, '/'), *pattern_delimiter = strchr(pattern, '/');
                if (!pathname_delimiter) pathname_delimiter = strchr(pathname, '\0');
                if (!pattern_delimiter) pattern_delimiter = strchr(pattern, '\0');
                if (!FileMatchesToPattern(pathname, pathname_delimiter, pattern, pattern_delimiter)) return 0;
                pathname = *pathname_delimiter ? pathname_delimiter + 1 : pathname_delimiter;
                pattern = *pattern_delimiter ? pattern_delimiter + 1 : pattern_delimiter;
        }
        while (*pattern == '\\' && (*(pattern + 1) == '*' || *(pattern + 1) == '@')) pattern += 2;
        return (!*pathname && !*pattern);
}

/*
 *  Transactional printf() to struct io_buffer structure.
 *  snprintf() will truncate, but io_printf() won't.
 *  Returns zero on success, nonzero otherwise.
 */
int io_printf(struct io_buffer *head, const char *fmt, ...)
{
        va_list args;
        int len, pos = head->read_avail, size = head->readbuf_size - pos;
        if (size <= 0) return -ENOMEM;
        va_start(args, fmt);
        len = vsnprintf(head->read_buf + pos, size, fmt, args);
        va_end(args);
        if (pos + len >= head->readbuf_size) return -ENOMEM;
        head->read_avail += len;
        return 0;
}

/*
 * Get realpath() of current process.
 * This function uses ccs_alloc(), so caller must ccs_free() if this function didn't return NULL.
 */
const char *GetEXE(void)
{
        if (current->mm) {
                struct vm_area_struct *vma = current->mm->mmap;
                while (vma) {
                        if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
                                return realpath_from_dentry(vma->vm_file->f_dentry, vma->vm_file->f_vfsmnt);
                        }
                        vma = vma->vm_next;
                }
        }
        return NULL;
}

const char *GetMSG(const int is_enforce)
{
        if (is_enforce) return "ERROR"; else return "WARNING";
}

/*************************  DOMAIN POLICY HANDLER  *************************/

/* Check whether the given access control is enabled. */
unsigned int CheckCCSFlags(const unsigned int index)
{
        const u8 profile = current->domain_info->profile;
        return sbin_init_started && index < CCS_MAX_CONTROL_INDEX
#if MAX_PROFILES != 256
                && profile < MAX_PROFILES
#endif
                && profile_ptr[profile] ? profile_ptr[profile]->value[index] : 0;
}
EXPORT_SYMBOL(CheckCCSFlags);

unsigned int TomoyoVerboseMode(void)
{
        return CheckCCSFlags(CCS_TOMOYO_VERBOSE);
}

/* Check whether the given access control is enforce mode. */
unsigned int CheckCCSEnforce(const unsigned int index)
{
        return CheckCCSFlags(index) == 3;
}
EXPORT_SYMBOL(CheckCCSEnforce);

/* Check whether the given access control is accept mode. */
unsigned int CheckCCSAccept(const unsigned int index)
{
        return CheckCCSFlags(index) == 1;
}
EXPORT_SYMBOL(CheckCCSAccept);

static struct profile *FindOrAssignNewProfile(const unsigned int profile)
{
        static DECLARE_MUTEX(profile_lock);
        struct profile *ptr = NULL;
        down(&profile_lock);
        if (profile < MAX_PROFILES && (ptr = profile_ptr[profile]) == NULL) {
                if ((ptr = alloc_element(sizeof(*ptr))) != NULL) {
                        int i;
                        for (i = 0; i < CCS_MAX_CONTROL_INDEX; i++) ptr->value[i] = ccs_control_array[i].current_value;
                        mb(); /* Instead of using spinlock. */
                        profile_ptr[profile] = ptr;
                }
        }
        up(&profile_lock);
        return ptr;
}

static int SetStatus(struct io_buffer *head)
{
        char *data = head->write_buf;
        unsigned int i, value;
        char *cp;
        struct profile *profile;
        if (!isRoot()) return -EPERM;
        i = simple_strtoul(data, &cp, 10);
        if (data != cp) {
                if (*cp != '-') return -EINVAL;
                data= cp + 1;
        }
        profile = FindOrAssignNewProfile(i);
        if (!profile) return -EINVAL;
        cp = strchr(data, '=');
        if (!cp) return -EINVAL;
        *cp = '\0';
        UpdateCounter(CCS_UPDATES_COUNTER_STATUS);
        if (strcmp(data, ccs_control_array[CCS_PROFILE_COMMENT].keyword) == 0) {
                profile->comment = SaveName(cp + 1);
                return 0;
        }
        if (sscanf(cp + 1, "%u", &value) != 1) return -EINVAL;
        if (strncmp(data, KEYWORD_MAC_FOR_CAPABILITY, KEYWORD_MAC_FOR_CAPABILITY_LEN) == 0) {
                return SetCapabilityStatus(data + KEYWORD_MAC_FOR_CAPABILITY_LEN, value, i);
        }
        for (i = 0; i < CCS_MAX_CONTROL_INDEX; i++) {
                if (strcmp(data, ccs_control_array[i].keyword)) continue;
                if (value > ccs_control_array[i].max_value) value = ccs_control_array[i].max_value;
                profile->value[i] = value;
                return 0;
        }
        return -EINVAL;
}

static int ReadStatus(struct io_buffer *head)
{
        if (!head->read_eof) {
                if (!isRoot()) return -EPERM;
                if (!head->read_var2) {
                        int step;
                        for (step = head->read_step; step < MAX_PROFILES * CCS_MAX_CONTROL_INDEX; step++) {
                                const int i = step / CCS_MAX_CONTROL_INDEX, j = step % CCS_MAX_CONTROL_INDEX;
                                const struct profile *profile = profile_ptr[i];
                                head->read_step = step;
                                if (!profile) continue;
                                switch (j) {
                                case -1: /* Dummy */
#ifndef CONFIG_TOMOYO
                                case CCS_TOMOYO_MAX_ACCEPT_ENTRY:
                                case CCS_TOMOYO_MAX_GRANT_LOG:
                                case CCS_TOMOYO_MAX_REJECT_LOG:
                                case CCS_TOMOYO_VERBOSE:
#endif
                                        continue;
                                }
                                if (j == CCS_PROFILE_COMMENT) {
                                        if (io_printf(head, "%u-%s=%s\n", i, ccs_control_array[CCS_PROFILE_COMMENT].keyword, profile->comment ? profile->comment->name : "")) break;
                                } else {
                                        if (io_printf(head, "%u-%s=%u\n", i, ccs_control_array[j].keyword, profile->value[j])) break;
                                }
                        }
                        if (step == MAX_PROFILES * CCS_MAX_CONTROL_INDEX) {
                                head->read_var2 = "";
                                head->read_step = 0;
                        }
                }
                if (head->read_var2) {
                        if (ReadCapabilityStatus(head) == 0) head->read_eof = 1;
                }
        }
        return 0;
}

/*************************  POLICY MANAGER HANDLER  *************************/

struct policy_manager_entry {
        struct policy_manager_entry *next;
        const struct path_info *manager;
        u8 is_domain;
        u8 is_deleted;
};

static struct policy_manager_entry *policy_manager_list = NULL;

static int AddManagerEntry(const char *manager, u8 is_delete)
{
        struct policy_manager_entry *new_entry, *ptr;
        static DECLARE_MUTEX(lock);
        const struct path_info *saved_manager;
        int error = -ENOMEM;
        u8 is_domain = 0;
        if (!isRoot()) return -EPERM;
        if (IsDomainDef(manager)) {
                if (!IsCorrectDomain(manager, __FUNCTION__)) return -EINVAL;
                is_domain = 1;
        } else {
                if (!IsCorrectPath(manager, 1, -1, -1, __FUNCTION__)) return -EINVAL;
        }
        if ((saved_manager = SaveName(manager)) == NULL) return -ENOMEM;
        down(&lock);
        for (ptr = policy_manager_list; ptr; ptr = ptr->next) {
                if (ptr->manager == saved_manager) {
                        ptr->is_deleted = is_delete;
                        error = 0;
                        goto out;
                }
        }
        if (is_delete) {
                error = -ENOENT;
                goto out;
        }
        if ((new_entry = alloc_element(sizeof(*new_entry))) == NULL) goto out;
        new_entry->manager = saved_manager;
        new_entry->is_domain = is_domain;
        mb(); /* Instead of using spinlock. */
        if ((ptr = policy_manager_list) != NULL) {
                while (ptr->next) ptr = ptr->next; ptr->next = new_entry;
        } else {
                policy_manager_list = new_entry;
        }
        error = 0;
 out:
        up(&lock);
        if (!error) UpdateCounter(CCS_UPDATES_COUNTER_MANAGER);
        return error;
}

static int AddManagerPolicy(struct io_buffer *head)
{
        const char *data = head->write_buf;
        int is_delete = 0;
        if (!isRoot()) return -EPERM;
        if (strncmp(data, KEYWORD_DELETE, KEYWORD_DELETE_LEN) == 0) {
                data += KEYWORD_DELETE_LEN;
                is_delete = 1;
        }
        return AddManagerEntry(data, is_delete);
}

static int ReadManagerPolicy(struct io_buffer *head)
{
        if (!head->read_eof) {
                struct policy_manager_entry *ptr = head->read_var2;
                if (!isRoot()) return -EPERM;
                if (!ptr) ptr = policy_manager_list;
                while (ptr) {
                        head->read_var2 = ptr;
                        if (!ptr->is_deleted && io_printf(head, "%s\n", ptr->manager->name)) break;
                        ptr = ptr->next;
                }
                if (!ptr) head->read_eof = 1;
        }
        return 0;
}

/* Check whether the current process is a policy manager. */
static int IsPolicyManager(void)
{
        struct policy_manager_entry *ptr;
        const char *exe;
        const struct path_info *domainname = current->domain_info->domainname;
        if (!sbin_init_started) return 1;
        for (ptr = policy_manager_list; ptr; ptr = ptr->next) {
                if (!ptr->is_deleted && ptr->is_domain && !pathcmp(domainname, ptr->manager)) return 1;
        }
        if ((exe = GetEXE()) == NULL) return 0;
        for (ptr = policy_manager_list; ptr; ptr = ptr->next) {
                if (!ptr->is_deleted && !ptr->is_domain && !strcmp(exe, ptr->manager->name)) break;
        }
        if (!ptr) { /* Reduce error messages. */
                static pid_t last_pid = 0;
                const pid_t pid = current->pid;
                if (last_pid != pid) {
                        printk("%s ( %s ) is not permitted to update policies.\n", domainname->name, exe);
                        last_pid = pid;
                }
        }
        ccs_free(exe);
        return ptr ? 1 : 0;
}

#ifdef CONFIG_TOMOYO

/*************************  DOMAIN POLICY HANDLER  *************************/

static int AddDomainPolicy(struct io_buffer *head)
{
        char *data = head->write_buf;
        struct domain_info *domain = head->write_var1;
        int is_delete = 0, is_select = 0, is_undelete = 0;
        unsigned int profile;
        if (!isRoot()) return -EPERM;
        if (strncmp(data, KEYWORD_DELETE, KEYWORD_DELETE_LEN) == 0) {
                data += KEYWORD_DELETE_LEN;
                is_delete = 1;
        } else if (strncmp(data, KEYWORD_SELECT, KEYWORD_SELECT_LEN) == 0) {
                data += KEYWORD_SELECT_LEN;
                is_select = 1;
        } else if (strncmp(data, KEYWORD_UNDELETE, KEYWORD_UNDELETE_LEN) == 0) {
                data += KEYWORD_UNDELETE_LEN;
                is_undelete = 1;
        }
        UpdateCounter(CCS_UPDATES_COUNTER_DOMAIN_POLICY);
        if (IsDomainDef(data)) {
                if (is_delete) {
                        DeleteDomain(data);
                        domain = NULL;
                } else if (is_select) {
                        domain = FindDomain(data);
                } else if (is_undelete) {
                        domain = UndeleteDomain(data);
                } else {
                        domain = FindOrAssignNewDomain(data, 0);
                }
                head->write_var1 = domain;
                return 0;
        }
        if (!domain) return -EINVAL;
        if (sscanf(data, KEYWORD_USE_PROFILE "%u", &profile) == 1 && profile < MAX_PROFILES) {
                if (profile_ptr[profile] || !sbin_init_started) domain->profile = (u8) profile;
        } else if (strncmp(data, KEYWORD_ALLOW_CAPABILITY, KEYWORD_ALLOW_CAPABILITY_LEN) == 0) {
                return AddCapabilityPolicy(data + KEYWORD_ALLOW_CAPABILITY_LEN, domain, is_delete);
        } else if (strncmp(data, KEYWORD_ALLOW_NETWORK, KEYWORD_ALLOW_NETWORK_LEN) == 0) {
                return AddNetworkPolicy(data + KEYWORD_ALLOW_NETWORK_LEN, domain, is_delete);
        } else if (strncmp(data, KEYWORD_ALLOW_SIGNAL, KEYWORD_ALLOW_SIGNAL_LEN) == 0) {
                return AddSignalPolicy(data + KEYWORD_ALLOW_SIGNAL_LEN, domain, is_delete);
        } else if (strncmp(data, KEYWORD_ALLOW_ARGV0, KEYWORD_ALLOW_ARGV0_LEN) == 0) {
                return AddArgv0Policy(data + KEYWORD_ALLOW_ARGV0_LEN, domain, is_delete);
        } else {
                return AddFilePolicy(data, domain, is_delete);
        }
        return -EINVAL;
}

static int ReadDomainPolicy(struct io_buffer *head)
{
        if (!head->read_eof) {
                struct domain_info *domain = head->read_var1;
                switch (head->read_step) {
                case 0: break;
                case 1: goto step1;
                case 2: goto step2;
                case 3: goto step3;
                default: return -EINVAL;
                }
                if (!isRoot()) return -EPERM;
                for (domain = &KERNEL_DOMAIN; domain; domain = domain->next) {
                        struct acl_info *ptr;
                        if (domain->is_deleted) continue;
                        head->read_var1 = domain;
                        head->read_var2 = NULL; head->read_step = 1;
                step1:
                        if (io_printf(head, "%s\n" KEYWORD_USE_PROFILE "%u\n%s\n", domain->domainname->name, domain->profile, domain->quota_warned ? "quota_exceeded\n" : "")) break;
                        head->read_var2 = domain->first_acl_ptr; head->read_step = 2;
                step2:
                        for (ptr = head->read_var2; ptr; ptr = ptr->next) {
                                const u8 acl_type = ptr->type;
                                const int pos = head->read_avail;
                                head->read_var2 = ptr;
                                if (ptr->is_deleted) continue;
                                if (acl_type == TYPE_FILE_ACL) {
                                        struct file_acl_record *ptr2 = (struct file_acl_record *) ptr;
                                        const unsigned char b = ptr2->u_is_group;
                                        if (io_printf(head, "%d %s%s", ptr2->perm,
                                                      b ? "@" : "",
                                                      b ? ptr2->u.group->group_name->name : ptr2->u.filename->name)
                                            || DumpCondition(head, ptr->cond)) {
                                                head->read_avail = pos; break;
                                        }
                                } else if (acl_type == TYPE_ARGV0_ACL) {
                                        struct argv0_acl_record *ptr2 = (struct argv0_acl_record *) ptr;
                                        if (io_printf(head, KEYWORD_ALLOW_ARGV0 "%s %s",
                                                      ptr2->filename->name, ptr2->argv0->name) ||
                                            DumpCondition(head, ptr->cond)) {
                                                head->read_avail = pos; break;
                                        }
                                } else if (acl_type == TYPE_CAPABILITY_ACL) {
                                        struct capability_acl_record *ptr2 = (struct capability_acl_record *) ptr;
                                        if (io_printf(head, KEYWORD_ALLOW_CAPABILITY "%s", capability2keyword(ptr2->capability)) ||
                                            DumpCondition(head, ptr->cond)) {
                                                head->read_avail = pos; break;
                                        }
                                } else if (acl_type == TYPE_IP_NETWORK_ACL) {
                                        struct ip_network_acl_record *ptr2 = (struct ip_network_acl_record *) ptr;
                                        if (io_printf(head, KEYWORD_ALLOW_NETWORK "%s ", network2keyword(ptr2->operation_type))) break;
                                        switch (ptr2->record_type) {
                                        case IP_RECORD_TYPE_ADDRESS_GROUP:
                                                if (io_printf(head, "@%s", ptr2->u.group->group_name->name)) goto print_ip_record_out;
                                                break;
                                        case IP_RECORD_TYPE_IPv4:
                                                {
                                                        const u32 min_address = ptr2->u.ipv4.min, max_address = ptr2->u.ipv4.max;
                                                        if (io_printf(head, "%u.%u.%u.%u", HIPQUAD(min_address))) goto print_ip_record_out;
                                                        if (min_address != max_address && io_printf(head, "-%u.%u.%u.%u", HIPQUAD(max_address))) goto print_ip_record_out;
                                                }
                                                break;
                                        case IP_RECORD_TYPE_IPv6:
                                                {
                                                        char buf[64];
                                                        const u16 *min_address = ptr2->u.ipv6.min, *max_address = ptr2->u.ipv6.max;
                                                        print_ipv6(buf, sizeof(buf), min_address);
                                                        if (io_printf(head, "%s", buf)) goto print_ip_record_out;
                                                        if (memcmp(min_address, max_address, 16)) {
                                                                print_ipv6(buf, sizeof(buf), max_address);
                                                                if (io_printf(head, "-%s", buf)) goto print_ip_record_out;
                                                        }
                                                }
                                                break;
                                        }
                                        {
                                                const u16 min_port = ptr2->min_port, max_port = ptr2->max_port;
                                                if (io_printf(head, " %u", min_port)) goto print_ip_record_out;
                                                if (min_port != max_port && io_printf(head, "-%u", max_port)) goto print_ip_record_out;
                                        }
                                        if (DumpCondition(head, ptr->cond)) {
                                        print_ip_record_out: ;
                                        head->read_avail = pos; break;
                                        }
                                } else if (acl_type == TYPE_SIGNAL_ACL) {
                                        struct signal_acl_record *ptr2 = (struct signal_acl_record *) ptr;
                                        if (io_printf(head, KEYWORD_ALLOW_SIGNAL "%u %s", ptr2->sig, ptr2->domainname->name) ||
                                            DumpCondition(head, ptr->cond)) {
                                                head->read_avail = pos; break;
                                        }
                                } else {
                                        const char *keyword = acltype2keyword(acl_type);
                                        if (keyword) {
                                                if (acltype2paths(acl_type) == 2) {
                                                        struct double_acl_record *ptr2 = (struct double_acl_record *) ptr;
                                                        const u8 b0 = ptr2->u1_is_group, b1 = ptr2->u2_is_group;
                                                        if (io_printf(head, "allow_%s %s%s %s%s", keyword, 
                                                                      b0 ? "@" : "", b0 ? ptr2->u1.group1->group_name->name : ptr2->u1.filename1->name,
                                                                      b1 ? "@" : "", b1 ? ptr2->u2.group2->group_name->name : ptr2->u2.filename2->name)
                                                            || DumpCondition(head, ptr->cond)) {
                                                                head->read_avail = pos; break;
                                                        }
                                                } else {
                                                        struct single_acl_record *ptr2 = (struct single_acl_record *) ptr;
                                                        const u8 b = ptr2->u_is_group;
                                                        if (io_printf(head, "allow_%s %s%s", keyword,
                                                                      b ? "@" : "", b ? ptr2->u.group->group_name->name : ptr2->u.filename->name)
                                                            || DumpCondition(head, ptr->cond)) {
                                                                head->read_avail = pos; break;
                                                        }
                                                }
                                        }
                                }
                        }
                        if (ptr) break;
                        head->read_var2 = NULL; head->read_step = 3;
                step3:
                        if (io_printf(head, "\n")) break;
                }
                if (!domain) head->read_eof = 1;
        }
        return 0;
}

static int ReadDomainProfile(struct io_buffer *head)
{
        if (!head->read_eof) {
                struct domain_info *domain;
                if (head->read_step == 0) {
                        head->read_var1 = &KERNEL_DOMAIN;
                        head->read_step = 1;
                }
                if (!isRoot()) return -EPERM;
                for (domain = head->read_var1; domain; domain = domain->next) {
                        if (domain->is_deleted) continue;
                        head->read_var1 = domain;
                        if (io_printf(head, "%u %s\n", domain->profile, domain->domainname->name)) break;
                }
                if (!domain) head->read_eof = 1;
        }
        return 0;
}

static int WritePID(struct io_buffer *head)
{
        head->read_step = (int) simple_strtoul(head->write_buf, NULL, 10);
        head->read_eof = 0;
        return 0;
}

static int ReadPID(struct io_buffer *head)
{
        if (head->read_avail == 0 && !head->read_eof) {
                const int pid = head->read_step;
                struct task_struct *p;
                struct domain_info *domain = NULL;
                /***** CRITICAL SECTION START *****/
                read_lock(&tasklist_lock);
                p = find_task_by_pid(pid);
                if (p) domain = p->domain_info;
                read_unlock(&tasklist_lock);
                /***** CRITICAL SECTION END *****/
                if (domain) io_printf(head, "%d %u %s", pid, domain->profile, domain->domainname->name);
                head->read_eof = 1;
        }
        return 0;
}

static int UpdateDomainProfile(struct io_buffer *head)
{
        char *data = head->write_buf;
        char *cp = strchr(data, ' ');
        struct domain_info *domain;
        unsigned int profile;
        if (!isRoot()) return -EPERM;
        if (!cp) return -EINVAL;
        *cp = '\0';
        domain = FindDomain(cp + 1);
        profile = simple_strtoul(data, NULL, 10);
        if (domain && profile < MAX_PROFILES && (profile_ptr[profile] || !sbin_init_started)) domain->profile = (u8) profile;
        UpdateCounter(CCS_UPDATES_COUNTER_DOMAIN_POLICY);
        return 0;
}

#endif

/*************************  EXCEPTION POLICY HANDLER  *************************/

#ifdef CONFIG_TOMOYO

static int AddExceptionPolicy(struct io_buffer *head)
{
        char *data = head->write_buf;
        int is_delete = 0;
        if (!isRoot()) return -EPERM;
        UpdateCounter(CCS_UPDATES_COUNTER_EXCEPTION_POLICY);
        if (strncmp(data, KEYWORD_DELETE, KEYWORD_DELETE_LEN) == 0) {
                data += KEYWORD_DELETE_LEN;
                is_delete = 1;
        }
        if (strncmp(data, KEYWORD_KEEP_DOMAIN, KEYWORD_KEEP_DOMAIN_LEN) == 0) {
                return AddDomainKeeperPolicy(data + KEYWORD_KEEP_DOMAIN_LEN, 0, is_delete);
        } else if (strncmp(data, KEYWORD_NO_KEEP_DOMAIN, KEYWORD_NO_KEEP_DOMAIN_LEN) == 0) {
                return AddDomainKeeperPolicy(data + KEYWORD_NO_KEEP_DOMAIN_LEN, 1, is_delete);
        } else if (strncmp(data, KEYWORD_INITIALIZE_DOMAIN, KEYWORD_INITIALIZE_DOMAIN_LEN) == 0) {
                return AddDomainInitializerPolicy(data + KEYWORD_INITIALIZE_DOMAIN_LEN, 0, is_delete, 0);
        } else if (strncmp(data, KEYWORD_NO_INITIALIZE_DOMAIN, KEYWORD_NO_INITIALIZE_DOMAIN_LEN) == 0) {
                return AddDomainInitializerPolicy(data + KEYWORD_NO_INITIALIZE_DOMAIN_LEN, 1, is_delete, 0);
        } else if (strncmp(data, KEYWORD_INITIALIZER, KEYWORD_INITIALIZER_LEN) == 0) {
                return AddDomainInitializerPolicy(data + KEYWORD_INITIALIZER_LEN, 0, is_delete, 1);
        } else if (strncmp(data, KEYWORD_NO_INITIALIZER, KEYWORD_NO_INITIALIZER_LEN) == 0) {
                return AddDomainInitializerPolicy(data + KEYWORD_NO_INITIALIZER_LEN, 1, is_delete, 1);
        } else if (strncmp(data, KEYWORD_ALIAS, KEYWORD_ALIAS_LEN) == 0) {
                return AddAliasPolicy(data + KEYWORD_ALIAS_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_AGGREGATOR, KEYWORD_AGGREGATOR_LEN) == 0) {
                return AddAggregatorPolicy(data + KEYWORD_AGGREGATOR_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_ALLOW_READ, KEYWORD_ALLOW_READ_LEN) == 0) {
                return AddGloballyReadablePolicy(data + KEYWORD_ALLOW_READ_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_FILE_PATTERN, KEYWORD_FILE_PATTERN_LEN) == 0) {
                return AddPatternPolicy(data + KEYWORD_FILE_PATTERN_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_PATH_GROUP, KEYWORD_PATH_GROUP_LEN) == 0) {
                return AddGroupPolicy(data + KEYWORD_PATH_GROUP_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_DENY_REWRITE, KEYWORD_DENY_REWRITE_LEN) == 0) {
                return AddNoRewritePolicy(data + KEYWORD_DENY_REWRITE_LEN, is_delete);
        } else if (strncmp(data, KEYWORD_ADDRESS_GROUP, KEYWORD_ADDRESS_GROUP_LEN) == 0) {
                return AddAddressGroupPolicy(data + KEYWORD_ADDRESS_GROUP_LEN, is_delete);
        }
        return -EINVAL;
}

static int ReadExceptionPolicy(struct io_buffer *head)
{
        if (!head->read_eof) {
                switch (head->read_step) {
                case 0:
                        if (!isRoot()) return -EPERM;
                        head->read_var2 = NULL; head->read_step = 1;
                case 1:
                        if (ReadDomainKeeperPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 2;
                case 2:
                        if (ReadGloballyReadablePolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 3;
                case 3:
                        if (ReadDomainInitializerPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 4;
                case 4:
                        if (ReadAliasPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 5;
                case 5:
                        if (ReadAggregatorPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 6;
                case 6:
                        if (ReadPatternPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 7;
                case 7:
                        if (ReadNoRewritePolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 8;
                case 8:
                        if (ReadGroupPolicy(head)) break;
                        head->read_var1 = head->read_var2 = NULL; head->read_step = 9;
                case 9:
                        if (ReadAddressGroupPolicy(head)) break;
                        head->read_eof = 1;
                        break;
                default:
                        return -EINVAL;
                }
        }
        return 0;
}

#endif

/*************************  SYSTEM POLICY HANDLER  *************************/

#ifdef CONFIG_SAKURA

static int AddSystemPolicy(struct io_buffer *head)
{
        char *data = head->write_buf;
        int is_delete = 0;
        if (!isRoot()) return -EPERM;
        UpdateCounter(CCS_UPDATES_COUNTER_SYSTEM_POLICY);
        if (strncmp(data, KEYWORD_DELETE, KEYWORD_DELETE_LEN) == 0) {
                data += KEYWORD_DELETE_LEN;
                is_delete = 1;
        }
        if (strncmp(data, KEYWORD_ALLOW_MOUNT, KEYWORD_ALLOW_MOUNT_LEN) == 0)
                return AddMountPolicy(data + KEYWORD_ALLOW_MOUNT_LEN, is_delete);
        if (strncmp(data, KEYWORD_DENY_UNMOUNT, KEYWORD_DENY_UNMOUNT_LEN) == 0)
                return AddNoUmountPolicy(data + KEYWORD_DENY_UNMOUNT_LEN, is_delete);
        if (strncmp(data, KEYWORD_ALLOW_CHROOT, KEYWORD_ALLOW_CHROOT_LEN) == 0)
                return AddChrootPolicy(data + KEYWORD_ALLOW_CHROOT_LEN, is_delete);
        if (strncmp(data, KEYWORD_ALLOW_PIVOT_ROOT, KEYWORD_ALLOW_PIVOT_ROOT_LEN) == 0)
                return AddPivotRootPolicy(data + KEYWORD_ALLOW_PIVOT_ROOT_LEN, is_delete);
        if (strncmp(data, KEYWORD_DENY_AUTOBIND, KEYWORD_DENY_AUTOBIND_LEN) == 0)
                return AddReservedPortPolicy(data + KEYWORD_DENY_AUTOBIND_LEN, is_delete);
        return -EINVAL;
}

static int ReadSystemPolicy(struct io_buffer *head)
{
        if (!head->read_eof) {
                switch (head->read_step) {
                case 0:
                        if (!isRoot()) return -EPERM;
                        head->read_var2 = NULL; head->read_step = 1;
                case 1:
                        if (ReadMountPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 2;
                case 2:
                        if (ReadNoUmountPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 3;
                case 3:
                        if (ReadChrootPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 4;
                case 4:
                        if (ReadPivotRootPolicy(head)) break;
                        head->read_var2 = NULL; head->read_step = 5;
                case 5:
                        if (ReadReservedPortPolicy(head)) break;
                        head->read_eof = 1;
                        break;
                default:
                        return -EINVAL;
                }
        }
        return 0;
}

#endif

/*************************  POLICY LOADER  *************************/

static int profile_loaded = 0;

static const char *ccs_loader = NULL;

static int __init CCS_loader_Setup(char *str)
{
        ccs_loader = str;
        return 0;
}

__setup("CCS_loader=", CCS_loader_Setup);

void CCS_LoadPolicy(const char *filename)
{
        if (sbin_init_started) return;
        /*
         * Check filename is /sbin/init or /sbin/ccs-start .
         * /sbin/ccs-start is a dummy filename in case where /sbin/init can't be passed.
         * You can create /sbin/ccs-start by "ln -s /bin/true /sbin/ccs-start", for
         * only the pathname is needed to activate Mandatory Access Control.
         */
        if (strcmp(filename, "/sbin/init") != 0 && strcmp(filename, "/sbin/ccs-start") != 0) return;
        /*
         * Don't activate MAC if the path given by 'CCS_loader=' option doesn't exist.
         * If initrd.img includes /sbin/init but real-root-dev has not mounted on / yet,
         * activating MAC will block the system since policies are not loaded yet.
         * So let do_execve() call this function everytime.
         */
        {
                struct nameidata nd;
                if (!ccs_loader) ccs_loader = "/sbin/ccs-init";
                if (path_lookup(ccs_loader, lookup_flags, &nd)) {
                        printk("Not activating Mandatory Access Control now since %s doesn't exist.\n", ccs_loader);
                        return;
                }
                path_release(&nd);
        }
#ifdef CONFIG_SAKURA
        printk("SAKURA: 1.5.0-pre   2007/08/09\n");
#endif
#ifdef CONFIG_TOMOYO
        printk("TOMOYO: 1.5.0-pre   2007/08/09\n");
#endif
        if (!profile_loaded) {
                char *argv[2], *envp[3];
                printk("Calling %s to load policy. Please wait.\n", ccs_loader);
                argv[0] = (char *) ccs_loader;
                argv[1] = NULL;
                envp[0] = "HOME=/";
                envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
                envp[2] = NULL;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,0)
                call_usermodehelper(argv[0], argv, envp, 1);
#else
                call_usermodehelper(argv[0], argv, envp);
#endif
                while (!profile_loaded) {
                        set_current_state(TASK_INTERRUPTIBLE);
                        schedule_timeout(HZ / 10);
                }
        }
        //if (!profile_loaded) panic("No profiles loaded. Run policy loader using 'init=' option.\n");
        printk("Mandatory Access Control activated.\n");
        sbin_init_started = 1;
        ccs_log_level = KERN_WARNING;
        { /* Check all profiles currently assigned to domains are defined. */
                struct domain_info *domain;
                for (domain = &KERNEL_DOMAIN; domain; domain = domain->next) {
                        const u8 profile = domain->profile;
                        if (!profile_ptr[profile]) panic("Profile %u (used by '%s') not defined.\n", profile, domain->domainname->name); 
                }
        }
}


/*************************  MAC Decision Delayer  *************************/

static DECLARE_WAIT_QUEUE_HEAD(query_wait);

static spinlock_t query_lock = SPIN_LOCK_UNLOCKED;

struct query_entry {
        struct list_head list;
        char *query;
        int query_len;
        unsigned int serial;
        int timer;
        int answer;
};

static LIST_HEAD(query_list);
static atomic_t queryd_watcher = ATOMIC_INIT(0);

int CheckSupervisor(const char *fmt, ...)
{
        va_list args;
        int error = -EPERM;
        int pos, len;
        static unsigned int serial = 0;
        struct query_entry *query_entry;
        if (!CheckCCSFlags(CCS_ALLOW_ENFORCE_GRACE)) return -EPERM;
        if (!atomic_read(&queryd_watcher)) return -EPERM;
        va_start(args, fmt);
        len = vsnprintf((char *) &pos, sizeof(pos) - 1, fmt, args) + 32;
        va_end(args);
        if ((query_entry = ccs_alloc(sizeof(*query_entry))) == NULL ||
                (query_entry->query = ccs_alloc(len)) == NULL) goto out;
        INIT_LIST_HEAD(&query_entry->list);
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        query_entry->serial = serial++;
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        pos = snprintf(query_entry->query, len - 1, "Q%u\n", query_entry->serial);
        va_start(args, fmt);
        vsnprintf(query_entry->query + pos, len - 1 - pos, fmt, args);
        query_entry->query_len = strlen(query_entry->query) + 1;
        va_end(args);
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        list_add_tail(&query_entry->list, &query_list);
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        UpdateCounter(CCS_UPDATES_COUNTER_QUERY);
        /* Give 10 seconds for supervisor's opinion. */
        for (query_entry->timer = 0; atomic_read(&queryd_watcher) && CheckCCSFlags(CCS_ALLOW_ENFORCE_GRACE) && query_entry->timer < 100; query_entry->timer++) {
                wake_up(&query_wait);
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(HZ / 10);
                if (query_entry->answer) break;
        }
        UpdateCounter(CCS_UPDATES_COUNTER_QUERY);
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        list_del(&query_entry->list);
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        switch (query_entry->answer) {
        case 1:
                /* Granted by administrator. */
                error = 0;
                break;
        case 0:
                /* Timed out. */
                break;
        default:
                /* Rejected by administrator. */
                break;
        }
 out: ;
        if (query_entry) ccs_free(query_entry->query);
        ccs_free(query_entry);
        return error;
}

static int PollQuery(struct file *file, poll_table *wait)
{
        int found;
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        found = !list_empty(&query_list);
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        if (found) return POLLIN | POLLRDNORM;
        poll_wait(file, &query_wait, wait);
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        found = !list_empty(&query_list);
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        if (found) return POLLIN | POLLRDNORM;
        return 0;
}

static int ReadQuery(struct io_buffer *head)
{
        struct list_head *tmp;
        int pos = 0, len = 0;
        char *buf;
        if (head->read_avail) return 0;
        if (head->read_buf) {
                ccs_free(head->read_buf); head->read_buf = NULL;
                head->readbuf_size = 0;
        }
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        list_for_each(tmp, &query_list) {
                struct query_entry *ptr = list_entry(tmp, struct query_entry, list);
                if (pos++ == head->read_step) {
                        len = ptr->query_len;
                        break;
                }
        }
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        if (!len) {
                head->read_step = 0;
                return 0;
        }
        if ((buf = ccs_alloc(len)) != NULL) {
                pos = 0;
                /***** CRITICAL SECTION START *****/
                spin_lock(&query_lock);
                list_for_each(tmp, &query_list) {
                        struct query_entry *ptr = list_entry(tmp, struct query_entry, list);
                        if (pos++ == head->read_step) {
                                /* Some query can be skiipped since query_list can change, but I don't care. */
                                if (len == ptr->query_len) memmove(buf, ptr->query, len);
                                break;
                        }
                }
                spin_unlock(&query_lock);
                /***** CRITICAL SECTION END *****/
                if (buf[0]) {
                        head->readbuf_size = head->read_avail = len;
                        head->read_buf = buf;
                        head->read_step++;
                } else {
                        ccs_free(buf);
                }
        }
        return 0;
}

static int WriteAnswer(struct io_buffer *head)
{
        char *data = head->write_buf;
        struct list_head *tmp;
        unsigned int serial, answer;
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        list_for_each(tmp, &query_list) {
                struct query_entry *ptr = list_entry(tmp, struct query_entry, list);
                ptr->timer = 0;
        }
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        if (sscanf(data, "A%u=%u", &serial, &answer) != 2) return -EINVAL;
        /***** CRITICAL SECTION START *****/
        spin_lock(&query_lock);
        list_for_each(tmp, &query_list) {
                struct query_entry *ptr = list_entry(tmp, struct query_entry, list);
                if (ptr->serial != serial) continue;
                if (!ptr->answer) ptr->answer = answer;
                break;
        }
        spin_unlock(&query_lock);
        /***** CRITICAL SECTION END *****/
        return 0;
}

/*************************  /proc INTERFACE HANDLER  *************************/

/* Policy updates counter. */
static unsigned int updates_counter[MAX_CCS_UPDATES_COUNTER];
static spinlock_t updates_counter_lock = SPIN_LOCK_UNLOCKED;

void UpdateCounter(const unsigned char index)
{
        /***** CRITICAL SECTION START *****/
        spin_lock(&updates_counter_lock);
        if (index < MAX_CCS_UPDATES_COUNTER) updates_counter[index]++;
        spin_unlock(&updates_counter_lock);
        /***** CRITICAL SECTION END *****/
}

static int ReadUpdatesCounter(struct io_buffer *head)
{
        if (!head->read_eof) {
                unsigned int counter[MAX_CCS_UPDATES_COUNTER];
                /***** CRITICAL SECTION START *****/
                spin_lock(&updates_counter_lock);
                memmove(counter, updates_counter, sizeof(updates_counter));
                memset(updates_counter, 0, sizeof(updates_counter));
                spin_unlock(&updates_counter_lock);
                /***** CRITICAL SECTION END *****/
                io_printf(head,
                                  "/proc/ccs/policy/system_policy:    %10u\n"
                                  "/proc/ccs/policy/domain_policy:    %10u\n"
                                  "/proc/ccs/policy/exception_policy: %10u\n"
                                  "/proc/ccs/status:                  %10u\n"
                                  "/proc/ccs/policy/query:            %10u\n"
                                  "/proc/ccs/policy/manager:          %10u\n"
                                  "/proc/ccs/info/grant_log:          %10u\n"
                                  "/proc/ccs/info/reject_log:         %10u\n",
                                  counter[CCS_UPDATES_COUNTER_SYSTEM_POLICY],
                                  counter[CCS_UPDATES_COUNTER_DOMAIN_POLICY],
                                  counter[CCS_UPDATES_COUNTER_EXCEPTION_POLICY],
                                  counter[CCS_UPDATES_COUNTER_STATUS],
                                  counter[CCS_UPDATES_COUNTER_QUERY],
                                  counter[CCS_UPDATES_COUNTER_MANAGER],
                                  counter[CCS_UPDATES_COUNTER_GRANT_LOG],
                                  counter[CCS_UPDATES_COUNTER_REJECT_LOG]);
                head->read_eof = 1;
        }
        return 0;
}

static int ReadVersion(struct io_buffer *head)
{
        if (!head->read_eof) {
                if (io_printf(head, "1\n") == 0) head->read_eof = 1;
        }
        return 0;
}

static int ReadMemoryCounter(struct io_buffer *head)
{
        if (!head->read_eof) {
                const int shared = GetMemoryUsedForSaveName(), private = GetMemoryUsedForElements(), dynamic = GetMemoryUsedForDynamic();
                if (io_printf(head, "Shared:  %10u\nPrivate: %10u\nDynamic: %10u\nTotal:   %10u\n", shared, private, dynamic, shared + private + dynamic) == 0) head->read_eof = 1;
        }
        return 0;
}

int CCS_OpenControl(const int type, struct file *file)
{
        struct io_buffer *head = ccs_alloc(sizeof(*head));
        if (!head) return -ENOMEM;
        init_MUTEX(&head->read_sem);
        init_MUTEX(&head->write_sem);
        switch (type) {
#ifdef CONFIG_TOMOYO
        case CCS_POLICY_DOMAINPOLICY:
                head->write = AddDomainPolicy;
                head->read = ReadDomainPolicy;
                break;
        case CCS_POLICY_EXCEPTIONPOLICY:
                head->write = AddExceptionPolicy;
                head->read = ReadExceptionPolicy;
                break;
        case CCS_POLICY_DOMAIN_STATUS:
                head->write = UpdateDomainProfile;
                head->read = ReadDomainProfile;
                break;
        case CCS_INFO_PROCESS_STATUS:
                head->write = WritePID;
                head->read = ReadPID;
                break;
        case CCS_INFO_GRANTLOG:
                head->poll = PollGrantLog;
                head->read = ReadGrantLog;
                break;
        case CCS_INFO_REJECTLOG:
                head->poll = PollRejectLog;
                head->read = ReadRejectLog;
                break;
        case CCS_INFO_SELFDOMAIN:
                head->read = ReadSelfDomain;
                break;
#endif
#ifdef CONFIG_SAKURA
        case CCS_POLICY_SYSTEMPOLICY:
                head->write = AddSystemPolicy;
                head->read = ReadSystemPolicy;
                break;
#endif
        case CCS_VERSION:
                head->read = ReadVersion;
                head->readbuf_size = 128;
                break;
        case CCS_INFO_MEMINFO:
                head->read = ReadMemoryCounter;
                head->readbuf_size = 128;
                break;
        case CCS_STATUS:
                head->write = SetStatus;
                head->read = ReadStatus;
                break;
        case CCS_POLICY_QUERY:
                head->poll = PollQuery;
                head->write = WriteAnswer;
                head->read = ReadQuery;
                break;
        case CCS_POLICY_MANAGER:
                head->write = AddManagerPolicy;
                head->read = ReadManagerPolicy;
                break;
        case CCS_INFO_UPDATESCOUNTER:
                head->read = ReadUpdatesCounter;
                break;
        }
        if (type != CCS_INFO_GRANTLOG && type != CCS_INFO_REJECTLOG && type != CCS_POLICY_QUERY) {
                if (!head->readbuf_size) head->readbuf_size = PAGE_SIZE * 2;
                if ((head->read_buf = ccs_alloc(head->readbuf_size)) == NULL) {
                        ccs_free(head);
                        return -ENOMEM;
                }
        }
        if (head->write) {
                head->writebuf_size = PAGE_SIZE * 2;
                if ((head->write_buf = ccs_alloc(head->writebuf_size)) == NULL) {
                        ccs_free(head->read_buf);
                        ccs_free(head);
                        return -ENOMEM;
                }
        }
        file->private_data = head;
        if (type == CCS_INFO_SELFDOMAIN) CCS_ReadControl(file, NULL, 0);
        else if (head->write == WriteAnswer) atomic_inc(&queryd_watcher);
        return 0;
}

static int CopyToUser(struct io_buffer *head, char __user * buffer, int buffer_len)
{
        int len = head->read_avail;
        char *cp = head->read_buf;
        if (len > buffer_len) len = buffer_len;
        if (len) {
                if (copy_to_user(buffer, cp, len)) return -EFAULT;
                head->read_avail -= len;
                memmove(cp, cp + len, head->read_avail);
        }
        return len;
}

int CCS_PollControl(struct file *file, poll_table *wait)
{
        struct io_buffer *head = file->private_data;
        if (!head->poll) return -ENOSYS;
        return head->poll(file, wait);
}

int CCS_ReadControl(struct file *file, char __user *buffer, const int buffer_len)
{
        int len = 0;
        struct io_buffer *head = file->private_data;
        if (!head->read) return -ENOSYS;
        if (!access_ok(VERIFY_WRITE, buffer, buffer_len)) return -EFAULT;
        if (down_interruptible(&head->read_sem)) return -EINTR;
        len = head->read(head);
        if (len >= 0) len = CopyToUser(head, buffer, buffer_len);
        up(&head->read_sem);
        return len;
}

int CCS_WriteControl(struct file *file, const char __user *buffer, const int buffer_len)
{
        struct io_buffer *head = file->private_data;
        int error = buffer_len;
        int avail_len = buffer_len;
        char *cp0 = head->write_buf;
        if (!head->write) return -ENOSYS;
        if (!access_ok(VERIFY_READ, buffer, buffer_len)) return -EFAULT;
        if (!isRoot()) return -EPERM;
        if (head->write != WritePID && !IsPolicyManager()) {
                return -EPERM; /* Forbid updating policies for non manager programs. */
        }
        if (down_interruptible(&head->write_sem)) return -EINTR;
        while (avail_len > 0) {
                char c;
                if (head->write_avail >= head->writebuf_size - 1) {
                        error = -ENOMEM;
                        break;
                } else if (get_user(c, buffer)) {
                        error = -EFAULT;
                        break;
                }
                buffer++; avail_len--;
                cp0[head->write_avail++] = c;
                if (c != '\n') continue;
                cp0[head->write_avail - 1] = '\0';
                head->write_avail = 0;
                NormalizeLine(cp0);
                head->write(head);
        }
        up(&head->write_sem);
        return error;
}


int CCS_CloseControl(struct file *file)
{
        struct io_buffer *head = file->private_data;
        if (head->write == WriteAnswer) atomic_dec(&queryd_watcher);
        else if (head->read == ReadMemoryCounter) profile_loaded = 1;
        ccs_free(head->read_buf); head->read_buf = NULL;
        ccs_free(head->write_buf); head->write_buf = NULL;
        ccs_free(head); head = NULL;
        file->private_data = NULL;
        return 0;
}