security/ccsecurity/util.c

/*
 * security/ccsecurity/util.c
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 *
 * Version: 1.8.0-pre   2010/09/01
 *
 * This file is applicable to both 2.4.30 and 2.6.11 and later.
 * See README.ccs for ChangeLog.
 *
 */

#include "internal.h"

/* Lock for protecting policy. */
DEFINE_MUTEX(ccs_policy_lock);

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

/* Index table for searching parent category. */
const u8 ccs_index2category[CCS_MAX_MAC_INDEX + CCS_MAX_CAPABILITY_INDEX] = {
        [CCS_MAC_FILE_EXECUTE]    = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_OPEN]       = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_CREATE]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_UNLINK]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MKDIR]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_RMDIR]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MKFIFO]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MKSOCK]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_TRUNCATE]   = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_SYMLINK]    = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MKBLOCK]    = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MKCHAR]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_LINK]       = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_RENAME]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_CHMOD]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_CHOWN]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_CHGRP]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_IOCTL]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_CHROOT]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_MOUNT]      = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_UMOUNT]     = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_FILE_PIVOT_ROOT] = CCS_MAC_CATEGORY_FILE,
        [CCS_MAC_ENVIRON]         = CCS_MAC_CATEGORY_MISC,
        [CCS_MAC_NETWORK_INET_STREAM_BIND]       = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_STREAM_LISTEN]     = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_STREAM_CONNECT]    = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_STREAM_ACCEPT]     = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_DGRAM_BIND]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_DGRAM_SEND]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_DGRAM_RECV]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_RAW_BIND]          = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_RAW_SEND]          = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_INET_RAW_RECV]          = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_STREAM_BIND]       = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_STREAM_LISTEN]     = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_STREAM_CONNECT]    = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_STREAM_ACCEPT]     = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_DGRAM_BIND]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_DGRAM_SEND]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_DGRAM_RECV]        = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_SEQPACKET_BIND]    = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_NETWORK_UNIX_SEQPACKET_ACCEPT]  = CCS_MAC_CATEGORY_NETWORK,
        [CCS_MAC_SIGNAL]          = CCS_MAC_CATEGORY_IPC,
        [CCS_MAX_MAC_INDEX + CCS_USE_ROUTE_SOCKET]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_USE_PACKET_SOCKET]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_REBOOT]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_VHANGUP]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_SETTIME]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_NICE]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_SETHOSTNAME]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_USE_KERNEL_MODULE]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_KEXEC_LOAD]
        = CCS_MAC_CATEGORY_CAPABILITY,
        [CCS_MAX_MAC_INDEX + CCS_SYS_PTRACE]
        = CCS_MAC_CATEGORY_CAPABILITY,
};

/* Utility functions. */

bool ccs_permstr(const char *string, const char *keyword)
{
        const char *cp = strstr(string, keyword);
        if (cp)
                return cp == string || *(cp - 1) == '/';
        return false;
}

/**
 * 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
                snprintf(buffer, buffer_len, "0x%lX", value);
}

/**
 * ccs_parse_name_union - Parse a ccs_name_union.
 *
 * @filename: Name or name group.
 * @ptr:      Pointer to "struct ccs_name_union".
 *
 * Returns true on success, false otherwise.
 */
bool ccs_parse_name_union(const char *filename, struct ccs_name_union *ptr)
{
        if (!ccs_correct_word(filename))
                return false;
        if (filename[0] == '@') {
                ptr->group = ccs_get_group(filename + 1, CCS_PATH_GROUP);
                ptr->is_group = true;
                return ptr->group != NULL;
        }
        ptr->filename = ccs_get_name(filename);
        ptr->is_group = false;
        return ptr->filename != NULL;
}

/**
 * ccs_parse_number_union - Parse a ccs_number_union.
 *
 * @data: Number or number range or number group.
 * @ptr:  Pointer to "struct ccs_number_union".
 *
 * Returns true on success, false otherwise.
 */
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])
                return false;
        if (data[0] == '@') {
                if (!ccs_correct_word(data))
                        return false;
                num->group = ccs_get_group(data + 1, CCS_NUMBER_GROUP);
                num->is_group = true;
                return num->group != NULL;
        }
        type = ccs_parse_ulong(&v, &data);
        if (!type)
                return false;
        num->values[0] = v;
        num->value_type[0] = type;
        if (!*data) {
                num->values[1] = v;
                num->value_type[1] = type;
                return true;
        }
        if (*data++ != '-')
                return false;
        type = ccs_parse_ulong(&v, &data);
        if (!type || *data)
                return false;
        num->values[1] = v;
        num->value_type[1] = type;
        return true;
}

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

/**
 * ccs_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 bool ccs_decimal(const char c)
{
        return c >= '0' && c <= '9';
}

/**
 * ccs_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 bool ccs_hexadecimal(const char c)
{
        return (c >= '0' && c <= '9') ||
                (c >= 'A' && c <= 'F') ||
                (c >= 'a' && c <= 'f');
}

/**
 * ccs_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 bool ccs_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 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_correct_word2 - Validate a string.
 *
 * @string: The string to check. Maybe non-'\0'-terminated.
 * @len:    Length of @string.
 *
 * Check whether the given string follows the naming rules.
 * Returns true if @string follows the naming rules, false otherwise.
 */
static bool ccs_correct_word2(const char *string, size_t len)
{
        const char *const start = string;
        bool in_repetition = false;
        unsigned char c;
        unsigned char d;
        unsigned char e;
        if (!len)
                goto out;
        while (len--) {
                c = *string++;
                if (c == '\\') {
                        if (!len--)
                                goto out;
                        c = *string++;
                        switch (c) {
                        case '\\':  /* "\\" */
                                continue;
                        case '$':   /* "\$" */
                        case '+':   /* "\+" */
                        case '?':   /* "\?" */
                        case '*':   /* "\*" */
                        case '@':   /* "\@" */
                        case 'x':   /* "\x" */
                        case 'X':   /* "\X" */
                        case 'a':   /* "\a" */
                        case 'A':   /* "\A" */
                        case '-':   /* "\-" */
                                continue;
                        case '{':   /* "/\{" */
                                if (string - 3 < start || *(string - 3) != '/')
                                        break;
                                in_repetition = true;
                                continue;
                        case '}':   /* "\}/" */
                                if (*string != '/')
                                        break;
                                if (!in_repetition)
                                        break;
                                in_repetition = false;
                                continue;
                        case '0':   /* "\ooo" */
                        case '1':
                        case '2':
                        case '3':
                                if (!len-- || !len--)
                                        break;
                                d = *string++;
                                e = *string++;
                                if (d < '0' || d > '7' || e < '0' || e > '7')
                                        break;
                                c = ccs_make_byte(c, d, e);
                                if (c <= ' ' || c >= 127)
                                        continue;
                        }
                        goto out;
                } else if (in_repetition && c == '/') {
                        goto out;
                } else if (c <= ' ' || c >= 127) {
                        goto out;
                }
        }
        if (in_repetition)
                goto out;
        return true;
 out:
        return false;
}

/**
 * ccs_correct_word - Validate a string.
 *
 * @string: The string to check.
 *
 * Check whether the given string follows the naming rules.
 * Returns true if @string follows the naming rules, false otherwise.
 */
bool ccs_correct_word(const char *string)
{
        return ccs_correct_word2(string, strlen(string));
}

/**
 * ccs_correct_path - Validate a pathname.
 *
 * @filename: The pathname to check.
 *
 * Check whether the given pathname follows the naming rules.
 * Returns true if @filename follows the naming rules, false otherwise.
 */
bool ccs_correct_path(const char *filename)
{
        return *filename == '/' && ccs_correct_word(filename);
}

/**
 * ccs_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_correct_domain(const unsigned char *domainname)
{
        if (!domainname || strncmp(domainname, CCS_ROOT_NAME,
                                   CCS_ROOT_NAME_LEN))
                goto out;
        domainname += CCS_ROOT_NAME_LEN;
        if (!*domainname)
                return true;
        if (*domainname++ != ' ')
                goto out;
        while (1) {
                const unsigned char *cp = strchr(domainname, ' ');
                if (!cp)
                        break;
                if (*domainname != '/' ||
                    !ccs_correct_word2(domainname, cp - domainname - 1))
                        goto out;
                domainname = cp + 1;
        }
        return ccs_correct_path(domainname);
 out:
        return false;
}

/**
 * ccs_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_domain_def(const unsigned char *buffer)
{
        return !strncmp(buffer, CCS_ROOT_NAME, CCS_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;
        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_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);
}

/**
 * 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_byte_range(filename + 1))
                                        filename += 3;
                                else
                                        return false;
                        }
                        break;
                case '\\':
                        if (c != '\\')
                                return false;
                        if (*++filename != '\\')
                                return false;
                        break;
                case '+':
                        if (!ccs_decimal(c))
                                return false;
                        break;
                case 'x':
                        if (!ccs_hexadecimal(c))
                                return false;
                        break;
                case 'a':
                        if (!ccs_alphabet_char(c))
                                return false;
                        break;
                case '0':
                case '1':
                case '2':
                case '3':
                        if (c == '\\' && ccs_byte_range(filename + 1)
                            && !strncmp(filename + 1, pattern, 3)) {
                                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_byte_range(filename + i + 1))
                                        i += 3;
                                else
                                        break; /* Bad pattern. */
                        }
                        return false; /* Not matched. */
                default:
                        j = 0;
                        c = *pattern;
                        if (c == '$') {
                                while (ccs_decimal(filename[j]))
                                        j++;
                        } else if (c == 'X') {
                                while (ccs_hexadecimal(filename[j]))
                                        j++;
                        } else if (c == 'A') {
                                while (ccs_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 '/' 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_pattern2 - Do pathname pattern matching.
 *
 * @f: The start of string to check.
 * @p: The start of pattern to compare.
 *
 * Returns true if @f matches @p, false otherwise.
 */
static bool ccs_path_matches_pattern2(const char *f, const char *p)
{
        const char *f_delimiter;
        const char *p_delimiter;
        while (*f && *p) {
                f_delimiter = strchr(f, '/');
                if (!f_delimiter)
                        f_delimiter = f + strlen(f);
                p_delimiter = strchr(p, '/');
                if (!p_delimiter)
                        p_delimiter = p + strlen(p);
                if (*p == '\\' && *(p + 1) == '{')
                        goto recursive;
                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;
 recursive:
        /*
         * The "\{" pattern is permitted only after '/' character.
         * This guarantees that below "*(p - 1)" is safe.
         * Also, the "\}" pattern is permitted only before '/' character
         * so that "\{" + "\}" pair will not break the "\-" operator.
         */
        if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
            *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
                return false; /* Bad pattern. */
        do {
                /* Compare current component with pattern. */
                if (!ccs_file_matches_pattern(f, f_delimiter, p + 2,
                                              p_delimiter - 2))
                        break;
                /* Proceed to next component. */
                f = f_delimiter;
                if (!*f)
                        break;
                f++;
                /* Continue comparison. */
                if (ccs_path_matches_pattern2(f, p_delimiter + 1))
                        return true;
                f_delimiter = strchr(f, '/');
        } while (f_delimiter);
        return false; /* Not matched. */
}

/**
 * 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.
 *   \*     Zero or more repetitions of characters other than '/'.
 *   \@     Zero or more repetitions of characters other than '/' or '.'.
 *   \?     1 byte character other than '/'.
 *   \$     One or more repetitions of decimal digits.
 *   \+     1 decimal digit.
 *   \X     One or more repetitions of hexadecimal digits.
 *   \x     1 hexadecimal digit.
 *   \A     One or more repetitions of alphabet characters.
 *   \a     1 alphabet character.
 *
 *   \-     Subtraction operator.
 *
 *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 *               /dir/dir/dir/ ).
 */
bool ccs_path_matches_pattern(const struct ccs_path_info *filename,
                              const struct ccs_path_info *pattern)
{
        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 directory and non-directory. */
        if (filename->is_dir != pattern->is_dir)
                return false;
        /* Compare the initial length without patterns. */
        if (strncmp(f, p, len))
                return false;
        f += len;
        p += len;
        return ccs_path_matches_pattern2(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) {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
                        struct path path = { vma->vm_file->f_vfsmnt,
                                             vma->vm_file->f_dentry };
                        cp = ccs_realpath_from_path(&path);
#else
                        cp = ccs_realpath_from_path(&vma->vm_file->f_path);
#endif
                        break;
                }
        }
        up_read(&mm->mmap_sem);
        return cp;
}

/**
 * ccs_get_config - Get config.
 *
 * @profile: Profile number.
 * @index:   Index number of functionality.
 *
 * Returns config.
 */
u8 ccs_get_config(const u8 profile, const u8 index)
{
        u8 config;
        const struct ccs_profile *p; 
        if (!ccs_policy_loaded)
                return CCS_CONFIG_DISABLED;
        p = ccs_profile(profile);
        config = p->config[index];
        if (config == CCS_CONFIG_USE_DEFAULT)
                config = p->config[ccs_index2category[index]
                                   + CCS_MAX_MAC_INDEX
                                   + CCS_MAX_CAPABILITY_INDEX];
        if (config == CCS_CONFIG_USE_DEFAULT)
                config = p->default_config;
        return config;
}

/**
 * ccs_init_request_info - Initialize "struct ccs_request_info" members.
 *
 * @r:      Pointer to "struct ccs_request_info" to initialize.
 * @index:  Index number of functionality.
 *
 * Returns mode.
 */
int ccs_init_request_info(struct ccs_request_info *r, const u8 index)
{
        u8 i;
        const char *buf;
        for (i = 0; i < 255; i++) {
                struct ccs_domain_info *domain = ccs_current_domain();
                const u8 profile = domain->profile;
                memset(r, 0, sizeof(*r));
                r->profile = profile;
                r->type = index;
                r->mode = ccs_get_mode(profile, index);
                r->param_type = CCS_TYPE_AUTO_TASK_ACL;
                ccs_check_acl(r, NULL);
                if (!r->granted)
                        return r->mode;
                buf = container_of(r->matched_acl, typeof(struct ccs_task_acl),
                                   head)->domainname->name;
                if (!ccs_assign_domain(buf, profile, domain->group, true))
                        break;
        }
        printk(KERN_WARNING "ERROR: Unable to transit to '%s' domain.\n",
               buf);
        force_sig(SIGKILL, current);
        return CCS_CONFIG_DISABLED;
}

/**
 * ccs_last_word - Get last component of a domainname.
 *
 * @name: Domainname to check.
 *
 * Returns the last word of @name.
 */
const char *ccs_last_word(const char *name)
{
        const char *cp = strrchr(name, ' ');
        if (cp)
                return cp + 1;
        return name;
}

/**
 * ccs_warn_log - Print warning or error message on console.
 *
 * @r:   Pointer to "struct ccs_request_info".
 * @fmt: The printf()'s format string, followed by parameters.
 */
void ccs_warn_log(struct ccs_request_info *r, const char *fmt, ...)
{
        va_list args;
        char *buffer;
        const struct ccs_domain_info * const domain = ccs_current_domain();
        if (!(ccs_get_config(domain->profile, r->type) & CCS_CONFIG_VERBOSE))
                return;
        buffer = kmalloc(4096, CCS_GFP_FLAGS);
        if (!buffer)
                return;
        va_start(args, fmt);
        vsnprintf(buffer, 4095, fmt, args);
        va_end(args);
        buffer[4095] = '\0';
        printk(KERN_WARNING "%s: Access %s denied for %s\n",
               r->mode == CCS_CONFIG_ENFORCING ? "ERROR" : "WARNING", buffer,
               ccs_last_word(domain->domainname->name));
        kfree(buffer);
}

/**
 * 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 * const domain = ccs_current_domain();
        struct ccs_acl_info *ptr;
        if (r->mode != CCS_CONFIG_LEARNING)
                return false;
        if (!domain)
                return true;
        list_for_each_entry_rcu(ptr, &domain->acl_info_list[0], list) {
                u16 perm;
                u8 i;
                if (ptr->is_deleted)
                        continue;
                switch (ptr->type) {
                case CCS_TYPE_PATH_ACL:
                        perm = container_of(ptr, struct ccs_path_acl,
                                            head)->perm;
                        break;
                case CCS_TYPE_PATH2_ACL:
                        perm = container_of(ptr, struct ccs_path2_acl,
                                            head)->perm;
                        break;
                case CCS_TYPE_PATH_NUMBER_ACL:
                        perm = container_of(ptr, struct ccs_path_number_acl,
                                            head)->perm;
                        break;
                case CCS_TYPE_MKDEV_ACL:
                        perm = container_of(ptr, struct ccs_mkdev_acl,
                                            head)->perm;
                        break;
                case CCS_TYPE_INET_ACL:
                        perm = container_of(ptr, struct ccs_inet_acl,
                                            head)->perm;
                        break;
                case CCS_TYPE_UNIX_ACL:
                        perm = container_of(ptr, struct ccs_unix_acl,
                                            head)->perm;
                        break;
                default:
                        perm = 1;
                }
                for (i = 0; i < 16; i++)
                        if (perm & (1 << i))
                                count++;
        }
        if (count < ccs_profile(domain->profile)->preference.
            learning_max_entry)
                return true;
        if (!domain->flags[CCS_DIF_QUOTA_WARNED]) {
                domain->flags[CCS_DIF_QUOTA_WARNED] = true;
                /* r->granted = false; */
                ccs_write_log(r, CCS_KEYWORD_QUOTA_EXCEEDED "\n");
                printk(KERN_WARNING "WARNING: "
                       "Domain '%s' has so many ACLs to hold. "
                       "Stopped learning mode.\n", domain->domainname->name);
        }
        return false;
}