security/ccsecurity/util.c

/*
 * security/ccsecurity/util.c
 *
 * Copyright (C) 2005-2009  NTT DATA CORPORATION
 *
 * Version: 1.7.0-pre   2009/08/08
 *
 * This file is applicable to both 2.4.30 and 2.6.11 and later.
 * See README.ccs for ChangeLog.
 *
 */

#include "internal.h"

DEFINE_MUTEX(ccs_policy_lock);

/* Has /sbin/init started? */
bool ccs_policy_loaded;

/* Capability name used by domain policy. */
const char *ccs_capability_list[CCS_MAX_CAPABILITY_INDEX] = {
        [CCS_INET_STREAM_SOCKET_CREATE]  = "inet_tcp_create",
        [CCS_INET_STREAM_SOCKET_LISTEN]  = "inet_tcp_listen",
        [CCS_INET_STREAM_SOCKET_CONNECT] = "inet_tcp_connect",
        [CCS_USE_INET_DGRAM_SOCKET]      = "use_inet_udp",
        [CCS_USE_INET_RAW_SOCKET]        = "use_inet_ip",
        [CCS_USE_ROUTE_SOCKET]           = "use_route",
        [CCS_USE_PACKET_SOCKET]          = "use_packet",
        [CCS_SYS_MOUNT]                  = "SYS_MOUNT",
        [CCS_SYS_UMOUNT]                 = "SYS_UMOUNT",
        [CCS_SYS_REBOOT]                 = "SYS_REBOOT",
        [CCS_SYS_CHROOT]                 = "SYS_CHROOT",
        [CCS_SYS_KILL]                   = "SYS_KILL",
        [CCS_SYS_VHANGUP]                = "SYS_VHANGUP",
        [CCS_SYS_SETTIME]                = "SYS_TIME",
        [CCS_SYS_NICE]                   = "SYS_NICE",
        [CCS_SYS_SETHOSTNAME]            = "SYS_SETHOSTNAME",
        [CCS_USE_KERNEL_MODULE]          = "use_kernel_module",
        [CCS_CREATE_FIFO]                = "create_fifo",
        [CCS_CREATE_BLOCK_DEV]           = "create_block_dev",
        [CCS_CREATE_CHAR_DEV]            = "create_char_dev",
        [CCS_CREATE_UNIX_SOCKET]         = "create_unix_socket",
        [CCS_SYS_LINK]                   = "SYS_LINK",
        [CCS_SYS_SYMLINK]                = "SYS_SYMLINK",
        [CCS_SYS_RENAME]                 = "SYS_RENAME",
        [CCS_SYS_UNLINK]                 = "SYS_UNLINK",
        [CCS_SYS_CHMOD]                  = "SYS_CHMOD",
        [CCS_SYS_CHOWN]                  = "SYS_CHOWN",
        [CCS_SYS_IOCTL]                  = "SYS_IOCTL",
        [CCS_SYS_KEXEC_LOAD]             = "SYS_KEXEC_LOAD",
        [CCS_SYS_PIVOT_ROOT]             = "SYS_PIVOT_ROOT",
        [CCS_SYS_PTRACE]                 = "SYS_PTRACE",
        [CCS_CONCEAL_MOUNT]              = "conceal_mount",
};

/* Profile table. Memory is allocated as needed. */
struct ccs_profile *ccs_profile_ptr[CCS_MAX_PROFILES];

/* Utility functions. */

/**
 * ccs_parse_ulong - Parse an "unsigned long" value.
 *
 * @result: Pointer to "unsigned long".
 * @str:    Pointer to string to parse.
 *
 * Returns value type on success, 0 otherwise.
 *
 * The @src is updated to point the first character after the value
 * on success.
 */
u8 ccs_parse_ulong(unsigned long *result, char **str)
{
        const char *cp = *str;
        char *ep;
        int base = 10;
        if (*cp == '0') {
                char c = *(cp + 1);
                if (c == 'x' || c == 'X') {
                        base = 16;
                        cp += 2;
                } else if (c >= '0' && c <= '7') {
                        base = 8;
                        cp++;
                }
        }
        *result = simple_strtoul(cp, &ep, base);
        if (cp == ep)
                return 0;
        *str = ep;
        switch (base) {
        case 16:
                return CCS_VALUE_TYPE_HEXADECIMAL;
        case 8:
                return CCS_VALUE_TYPE_OCTAL;
        default:
                return CCS_VALUE_TYPE_DECIMAL;
        }
}

/**
 * ccs_print_ulong - Print an "unsigned long" value.
 *
 * @buffer:     Pointer to buffer.
 * @buffer_len: Size of @buffer.
 * @value:      An "unsigned long" value.
 * @type:       Type of @value.
 *
 * Returns nothing.
 */
void ccs_print_ulong(char *buffer, const int buffer_len,
                     const unsigned long value, const u8 type)
{
        if (type == CCS_VALUE_TYPE_DECIMAL)
                snprintf(buffer, buffer_len, "%lu", value);
        else if (type == CCS_VALUE_TYPE_OCTAL)
                snprintf(buffer, buffer_len, "0%lo", value);
        else if (type == CCS_VALUE_TYPE_HEXADECIMAL)
                snprintf(buffer, buffer_len, "0x%lX", value);
        else
                snprintf(buffer, buffer_len, "type(%u)", type);
}

bool ccs_parse_name_union(const char *filename, struct ccs_name_union *ptr)
{
        if (!ccs_is_correct_path(filename, 0, 0, 0))
                return false;
        if (filename[0] == '@') {
                ptr->group = ccs_get_path_group(filename + 1);
                ptr->is_group = true;
                return ptr->group != NULL;
        }
        ptr->filename = ccs_get_name(filename);
        ptr->is_group = false;
        return ptr->filename != NULL;
}

bool ccs_parse_number_union(char *data, struct ccs_number_union *num)
{
        u8 type;
        unsigned long v;
        memset(num, 0, sizeof(*num));
        if (data[0] == '@') {
                if (!ccs_is_correct_path(data, 0, 0, 0))
                        return false;
                num->group = ccs_get_number_group(data + 1);
                num->is_group = true;
                return num->group != NULL;
        }
        type = ccs_parse_ulong(&v, &data);
        if (!type)
                return false;
        num->values[0] = v;
        num->min_type = type;
        if (!*data) {
                num->values[1] = v;
                num->max_type = type;
                return true;
        }
        if (*data++ != '-')
                return false;
        type = ccs_parse_ulong(&v, &data);
        if (!type || *data)
                return false;
        num->values[1] = v;
        num->max_type = type;
        return true;
}

/**
 * ccs_is_byte_range - Check whether the string isa \ooo style octal value.
 *
 * @str: Pointer to the string.
 *
 * Returns true if @str is a \ooo style octal value, false otherwise.
 */
static inline bool ccs_is_byte_range(const char *str)
{
        return *str >= '0' && *str++ <= '3' &&
                *str >= '0' && *str++ <= '7' &&
                *str >= '0' && *str <= '7';
}

/**
 * ccs_is_decimal - Check whether the character is a decimal character.
 *
 * @c: The character to check.
 *
 * Returns true if @c is a decimal character, false otherwise.
 */
static inline bool ccs_is_decimal(const char c)
{
        return c >= '0' && c <= '9';
}

/**
 * ccs_is_hexadecimal - Check whether the character is a hexadecimal character.
 *
 * @c: The character to check.
 *
 * Returns true if @c is a hexadecimal character, false otherwise.
 */
static inline bool ccs_is_hexadecimal(const char c)
{
        return (c >= '0' && c <= '9') ||
                (c >= 'A' && c <= 'F') ||
                (c >= 'a' && c <= 'f');
}

/**
 * ccs_is_alphabet_char - Check whether the character is an alphabet.
 *
 * @c: The character to check.
 *
 * Returns true if @c is an alphabet character, false otherwise.
 */
static inline bool ccs_is_alphabet_char(const char c)
{
        return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}

/**
 * ccs_make_byte - Make byte value from three octal characters.
 *
 * @c1: The first character.
 * @c2: The second character.
 * @c3: The third character.
 *
 * Returns byte value.
 */
static inline u8 ccs_make_byte(const u8 c1, const u8 c2, const u8 c3)
{
        return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
}

/**
 * ccs_str_starts - Check whether the given string starts with the given keyword.
 *
 * @src:  Pointer to pointer to the string.
 * @find: Pointer to the keyword.
 *
 * Returns true if @src starts with @find, false otherwise.
 *
 * The @src is updated to point the first character after the @find
 * if @src starts with @find.
 */
bool ccs_str_starts(char **src, const char *find)
{
        const int len = strlen(find);
        char *tmp = *src;
        if (strncmp(tmp, find, len))
                return false;
        tmp += len;
        *src = tmp;
        return true;
}

/**
 * ccs_normalize_line - Format string.
 *
 * @buffer: The line to normalize.
 *
 * Leading and trailing whitespaces are removed.
 * Multiple whitespaces are packed into single space.
 *
 * Returns nothing.
 */
void ccs_normalize_line(unsigned char *buffer)
{
        unsigned char *sp = buffer;
        unsigned char *dp = buffer;
        bool first = true;
        while (*sp && (*sp <= ' ' || *sp >= 127))
                sp++;
        while (*sp) {
                if (!first)
                        *dp++ = ' ';
                first = false;
                while (*sp > ' ' && *sp < 127)
                        *dp++ = *sp++;
                while (*sp && (*sp <= ' ' || *sp >= 127))
                        sp++;
        }
        *dp = '\0';
}

/**
 * ccs_tokenize - Tokenize string.
 *
 * @buffer: The line to tokenize.
 * @w:      Pointer to "char *".
 * @size:   Sizeof @w .
 *
 * Returns true on success, false otherwise.
 */
bool ccs_tokenize(char *buffer, char *w[], size_t size)
{
        int count = size / sizeof(char *);
        int i;
        for (i = 0; i < count; i++)
                w[i] = "";
        for (i = 0; i < count; i++) {
                char *cp = strchr(buffer, ' ');
                if (cp)
                        *cp = '\0';
                w[i] = buffer;
                if (!cp)
                        break;
                buffer = cp + 1;
        }
        return i < count || !*buffer;
}

/**
 * ccs_is_correct_path - Validate a pathname.
 * @filename:     The pathname to check.
 * @start_type:   Should the pathname start with '/'?
 *                1 = must / -1 = must not / 0 = don't care
 * @pattern_type: Can the pathname contain a wildcard?
 *                1 = must / -1 = must not / 0 = don't care
 * @end_type:     Should the pathname end with '/'?
 *                1 = must / -1 = must not / 0 = don't care
 *
 * Check whether the given filename follows the naming rules.
 * Returns true if @filename follows the naming rules, false otherwise.
 */
bool ccs_is_correct_path(const char *filename, const s8 start_type,
                         const s8 pattern_type, const s8 end_type)
{
        bool contains_pattern = false;
        unsigned char c;
        unsigned char d;
        unsigned char 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 = *(filename + strlen(filename) - 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 (1) {
                c = *filename++;
                if (!c)
                        break;
                if (c == '\\') {
                        c = *filename++;
                        switch (c) {
                        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 = true;
                                continue;
                        case '0':   /* "\ooo" */
                        case '1':
                        case '2':
                        case '3':
                                d = *filename++;
                                if (d < '0' || d > '7')
                                        break;
                                e = *filename++;
                                if (e < '0' || e > '7')
                                        break;
                                c = ccs_make_byte(c, d, e);
                                if (c && (c <= ' ' || c >= 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 true;
 out:
        printk(KERN_DEBUG "Invalid pathname '%s'\n", original_filename);
        return false;
}

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

/**
 * ccs_is_domain_def - Check whether the given token can be a domainname.
 *
 * @buffer: The token to check.
 *
 * Returns true if @buffer possibly be a domainname, false otherwise.
 */
bool ccs_is_domain_def(const unsigned char *buffer)
{
        return !strncmp(buffer, ROOT_NAME, ROOT_NAME_LEN);
}

/**
 * ccs_find_domain - Find a domain by the given name.
 *
 * @domainname: The domainname to find.
 *
 * Returns pointer to "struct ccs_domain_info" if found, NULL otherwise.
 *
 * Caller holds ccs_read_lock().
 */
struct ccs_domain_info *ccs_find_domain(const char *domainname)
{
        struct ccs_domain_info *domain;
        struct ccs_path_info name;
        ccs_check_read_lock();
        name.name = domainname;
        ccs_fill_path_info(&name);
        list_for_each_entry_rcu(domain, &ccs_domain_list, list) {
                if (!domain->is_deleted &&
                    !ccs_pathcmp(&name, domain->domainname))
                        return domain;
        }
        return NULL;
}

/**
 * ccs_path_depth - Evaluate the number of '/' in a string.
 *
 * @pathname: The string to evaluate.
 *
 * Returns path depth of the string.
 *
 * I score 2 for each of the '/' in the @pathname
 * and score 1 if the @pathname ends with '/'.
 */
static int ccs_path_depth(const char *pathname)
{
        int i = 0;
        if (pathname) {
                const char *ep = pathname + strlen(pathname);
                if (pathname < ep--) {
                        if (*ep != '/')
                                i++;
                        while (pathname <= ep)
                                if (*ep-- == '/')
                                        i += 2;
                }
        }
        return i;
}

/**
 * ccs_const_part_length - Evaluate the initial length without a pattern in a token.
 *
 * @filename: The string to evaluate.
 *
 * Returns the initial length without a pattern in @filename.
 */
static int ccs_const_part_length(const char *filename)
{
        char c;
        int len = 0;
        if (!filename)
                return 0;
        while (1) {
                c = *filename++;
                if (!c)
                        break;
                if (c != '\\') {
                        len++;
                        continue;
                }
                c = *filename++;
                switch (c) {
                case '\\':  /* "\\" */
                        len += 2;
                        continue;
                case '0':   /* "\ooo" */
                case '1':
                case '2':
                case '3':
                        c = *filename++;
                        if (c < '0' || c > '7')
                                break;
                        c = *filename++;
                        if (c < '0' || c > '7')
                                break;
                        len += 4;
                        continue;
                }
                break;
        }
        return len;
}

/**
 * ccs_fill_path_info - Fill in "struct ccs_path_info" members.
 *
 * @ptr: Pointer to "struct ccs_path_info" to fill in.
 *
 * The caller sets "struct ccs_path_info"->name.
 */
void ccs_fill_path_info(struct ccs_path_info *ptr)
{
        const char *name = ptr->name;
        const int len = strlen(name);
        ptr->total_len = len;
        ptr->const_len = ccs_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 = ccs_path_depth(name);
}

/**
 * ccs_file_matches_pattern2 - Pattern matching without '/' character
 * and "\-" pattern.
 *
 * @filename:     The start of string to check.
 * @filename_end: The end of string to check.
 * @pattern:      The start of pattern to compare.
 * @pattern_end:  The end of pattern to compare.
 *
 * Returns true if @filename matches @pattern, false otherwise.
 */
static bool ccs_file_matches_pattern2(const char *filename,
                                      const char *filename_end,
                                      const char *pattern,
                                      const char *pattern_end)
{
        while (filename < filename_end && pattern < pattern_end) {
                char c;
                if (*pattern != '\\') {
                        if (*filename++ != *pattern++)
                                return false;
                        continue;
                }
                c = *filename;
                pattern++;
                switch (*pattern) {
                        int i;
                        int j;
                case '?':
                        if (c == '/') {
                                return false;
                        } else if (c == '\\') {
                                if (filename[1] == '\\')
                                        filename++;
                                else if (ccs_is_byte_range(filename + 1))
                                        filename += 3;
                                else
                                        return false;
                        }
                        break;
                case '\\':
                        if (c != '\\')
                                return false;
                        if (*++filename != '\\')
                                return false;
                        break;
                case '+':
                        if (!ccs_is_decimal(c))
                                return false;
                        break;
                case 'x':
                        if (!ccs_is_hexadecimal(c))
                                return false;
                        break;
                case 'a':
                        if (!ccs_is_alphabet_char(c))
                                return false;
                        break;
                case '0':
                case '1':
                case '2':
                case '3':
                        if (c == '\\' && ccs_is_byte_range(filename + 1)
                            && strncmp(filename + 1, pattern, 3) == 0) {
                                filename += 3;
                                pattern += 2;
                                break;
                        }
                        return false; /* Not matched. */
                case '*':
                case '@':
                        for (i = 0; i <= filename_end - filename; i++) {
                                if (ccs_file_matches_pattern2(filename + i,
                                                              filename_end,
                                                              pattern + 1,
                                                              pattern_end))
                                        return true;
                                c = filename[i];
                                if (c == '.' && *pattern == '@')
                                        break;
                                if (c != '\\')
                                        continue;
                                if (filename[i + 1] == '\\')
                                        i++;
                                else if (ccs_is_byte_range(filename + i + 1))
                                        i += 3;
                                else
                                        break; /* Bad pattern. */
                        }
                        return false; /* Not matched. */
                default:
                        j = 0;
                        c = *pattern;
                        if (c == '$') {
                                while (ccs_is_decimal(filename[j]))
                                        j++;
                        } else if (c == 'X') {
                                while (ccs_is_hexadecimal(filename[j]))
                                        j++;
                        } else if (c == 'A') {
                                while (ccs_is_alphabet_char(filename[j]))
                                        j++;
                        }
                        for (i = 1; i <= j; i++) {
                                if (ccs_file_matches_pattern2(filename + i,
                                                              filename_end,
                                                              pattern + 1,
                                                              pattern_end))
                                        return true;
                        }
                        return false; /* Not matched or bad pattern. */
                }
                filename++;
                pattern++;
        }
        while (*pattern == '\\' &&
               (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
                pattern += 2;
        return filename == filename_end && pattern == pattern_end;
}

/**
 * ccs_file_matches_pattern - Pattern matching without without '/' character.
 *
 * @filename:     The start of string to check.
 * @filename_end: The end of string to check.
 * @pattern:      The start of pattern to compare.
 * @pattern_end:  The end of pattern to compare.
 *
 * Returns true if @filename matches @pattern, false otherwise.
 */
static bool ccs_file_matches_pattern(const char *filename,
                                     const char *filename_end,
                                     const char *pattern,
                                     const char *pattern_end)
{
        const char *pattern_start = pattern;
        bool first = true;
        bool result;
        while (pattern < pattern_end - 1) {
                /* Split at "\-" pattern. */
                if (*pattern++ != '\\' || *pattern++ != '-')
                        continue;
                result = ccs_file_matches_pattern2(filename, filename_end,
                                                   pattern_start, pattern - 2);
                if (first)
                        result = !result;
                if (result)
                        return false;
                first = false;
                pattern_start = pattern;
        }
        result = ccs_file_matches_pattern2(filename, filename_end,
                                           pattern_start, pattern_end);
        return first ? result : !result;
}

/**
 * ccs_path_matches_pattern - Check whether the given filename matches the given pattern.
 * @filename: The filename to check.
 * @pattern:  The pattern to compare.
 *
 * Returns true if matches, false 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.
 */
bool ccs_path_matches_pattern(const struct ccs_path_info *filename,
                              const struct ccs_path_info *pattern)
{
        /*
          if (!filename || !pattern)
          return false;
        */
        const char *f = filename->name;
        const char *p = pattern->name;
        const int len = pattern->const_len;
        /* If @pattern doesn't contain pattern, I can use strcmp(). */
        if (!pattern->is_patterned)
                return !ccs_pathcmp(filename, pattern);
        /* Don't compare if the number of '/' differs. */
        if (filename->depth != pattern->depth)
                return false;
        /* Compare the initial length without patterns. */
        if (strncmp(f, p, len))
                return false;
        f += len;
        p += len;
        /* Main loop. Compare each directory component. */
        while (*f && *p) {
                const char *f_delimiter = strchr(f, '/');
                const char *p_delimiter = strchr(p, '/');
                if (!f_delimiter)
                        f_delimiter = f + strlen(f);
                if (!p_delimiter)
                        p_delimiter = p + strlen(p);
                if (!ccs_file_matches_pattern(f, f_delimiter, p, p_delimiter))
                        return false;
                f = f_delimiter;
                if (*f)
                        f++;
                p = p_delimiter;
                if (*p)
                        p++;
        }
        /* Ignore trailing "\*" and "\@" in @pattern. */
        while (*p == '\\' &&
               (*(p + 1) == '*' || *(p + 1) == '@'))
                p += 2;
        return !*f && !*p;
}

/**
 * ccs_get_exe - Get ccs_realpath() of current process.
 *
 * Returns the ccs_realpath() of current process on success, NULL otherwise.
 *
 * This function uses kzalloc(), so the caller must kfree()
 * if this function didn't return NULL.
 */
const char *ccs_get_exe(void)
{
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma;
        const char *cp = NULL;
        if (!mm)
                return NULL;
        down_read(&mm->mmap_sem);
        for (vma = mm->mmap; vma; vma = vma->vm_next) {
                if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
                        cp = ccs_realpath_from_dentry(vma->vm_file->f_dentry,
                                                      vma->vm_file->f_vfsmnt);
                        break;
                }
        }
        up_read(&mm->mmap_sem);
        return cp;
}

/**
 * ccs_get_msg - Get warning message.
 *
 * @is_enforce: Is it enforcing mode?
 *
 * Returns "ERROR" or "WARNING".
 */
const char *ccs_get_msg(const bool is_enforce)
{
        if (is_enforce)
                return "ERROR";
        else
                return "WARNING";
}

/**
 * ccs_can_sleep - Check whether it is permitted to do operations that may sleep.
 *
 * Returns true if it is permitted to do operations that may sleep,
 * false otherwise.
 *
 * TOMOYO Linux supports interactive enforcement that lets processes
 * wait for the administrator's decision.
 * All hooks but the one for ccs_may_autobind() are inserted where
 * it is permitted to do operations that may sleep.
 * Thus, this warning should not happen.
 */
bool ccs_can_sleep(void)
{
        static u8 count = 20;
        if (likely(!in_interrupt()))
                return true;
        if (count) {
                count--;
                printk(KERN_ERR "BUG: sleeping function called "
                       "from invalid context.\n");
                dump_stack();
        }
        return false;
}

/**
 * ccs_check_flags - Check mode for specified functionality.
 *
 * @domain: Pointer to "struct ccs_domain_info". NULL for ccs_current_domain().
 * @index:  The functionality to check mode.
 *
 * Returns the mode of specified functionality.
 */
unsigned int ccs_check_flags(const struct ccs_domain_info *domain,
                             const u8 index)
{
        u8 profile;
        if (!domain)
                domain = ccs_current_domain();
        profile = domain->profile;
        return ccs_policy_loaded && index < CCS_MAX_CONTROL_INDEX
#if CCS_MAX_PROFILES != 256
                && profile < CCS_MAX_PROFILES
#endif
                && ccs_profile_ptr[profile] ?
                ccs_profile_ptr[profile]->value[index] : 0;
}

/**
 * ccs_cap2keyword - Convert capability operation to capability name.
 *
 * @operation: The capability index.
 *
 * Returns the name of the specified capability's name.
 */
const char *ccs_cap2keyword(const u8 operation)
{
        return operation < CCS_MAX_CAPABILITY_INDEX
                ? ccs_capability_list[operation] : NULL;
}

/**
 * ccs_init_request_info - Initialize "struct ccs_request_info" members.
 *
 * @r:      Pointer to "struct ccs_request_info" to initialize.
 * @domain: Pointer to "struct ccs_domain_info". NULL for ccs_current_domain().
 * @index:  Index number of functionality.
 */
void ccs_init_request_info(struct ccs_request_info *r,
                           struct ccs_domain_info *domain, const u8 index)
{
        memset(r, 0, sizeof(*r));
        if (!domain)
                domain = ccs_current_domain();
        r->domain = domain;
        r->profile = domain->profile;
        if (index < CCS_MAX_CONTROL_INDEX)
                r->mode = ccs_check_flags(domain, index);
}

/**
 * ccs_verbose_mode - Check whether TOMOYO is verbose mode.
 *
 * @domain: Pointer to "struct ccs_domain_info". NULL for ccs_current_domain().
 *
 * Returns true if domain policy violation warning should be printed to
 * console.
 */
bool ccs_verbose_mode(const struct ccs_domain_info *domain)
{
        return ccs_check_flags(domain, CCS_VERBOSE) != 0;
}

/**
 * ccs_domain_quota_ok - Check for domain's quota.
 *
 * @r: Pointer to "struct ccs_request_info".
 *
 * Returns true if the domain is not exceeded quota, false otherwise.
 *
 * Caller holds ccs_read_lock().
 */
bool ccs_domain_quota_ok(struct ccs_request_info *r)
{
        unsigned int count = 0;
        struct ccs_domain_info *domain = r->domain;
        struct ccs_acl_info *ptr;
        ccs_check_read_lock();
        if (r->mode != 1)
                return false;
        if (!domain)
                return true;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
                if (ptr->is_deleted)
                        continue;
                switch (ptr->type) {
                        struct ccs_single_path_acl_record *acl1;
                        struct ccs_double_path_acl_record *acl2;
                        u16 perm;
                case CCS_TYPE_SINGLE_PATH_ACL:
                        acl1 = container_of(ptr,
                                            struct ccs_single_path_acl_record,
                                            head);
                        perm = acl1->perm;
                        if (perm & (1 << CCS_TYPE_EXECUTE_ACL))
                                count++;
                        if (perm & ((1 << CCS_TYPE_READ_ACL) |
                                    (1 << CCS_TYPE_WRITE_ACL)))
                                count++;
                        if (perm & (1 << CCS_TYPE_CREATE_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_UNLINK_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_MKDIR_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_RMDIR_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_MKFIFO_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_MKSOCK_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_MKBLOCK_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_MKCHAR_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_TRUNCATE_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_SYMLINK_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_REWRITE_ACL))
                                count++;
                        break;
                case CCS_TYPE_DOUBLE_PATH_ACL:
                        acl2 = container_of(ptr,
                                            struct ccs_double_path_acl_record,
                                            head);
                        perm = acl2->perm;
                        if (perm & (1 << CCS_TYPE_LINK_ACL))
                                count++;
                        if (perm & (1 << CCS_TYPE_RENAME_ACL))
                                count++;
                        break;
                case CCS_TYPE_EXECUTE_HANDLER:
                case CCS_TYPE_DENIED_EXECUTE_HANDLER:
                        break;
                default:
                        count++;
                }
        }
        if (count < ccs_check_flags(domain, CCS_MAX_ACCEPT_ENTRY))
                return true;
        if (!domain->quota_warned) {
                domain->quota_warned = true;
                printk(KERN_WARNING "TOMOYO-WARNING: "
                       "Domain '%s' has so many ACLs to hold. "
                       "Stopped learning mode.\n", domain->domainname->name);
        }
        return false;
}