/* * security/tomoyo/util.c * * Utility functions for TOMOYO. * * Copyright (C) 2005-2010 NTT DATA CORPORATION */ #include #include "common.h" /* Lock for protecting policy. */ DEFINE_MUTEX(tomoyo_policy_lock); /* Has /sbin/init started? */ bool tomoyo_policy_loaded; /** * tomoyo_permstr - Find permission keywords. * * @string: String representation for permissions in foo/bar/buz format. * @keyword: Keyword to find from @string/ * * Returns ture if @keyword was found in @string, false otherwise. * * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2. */ bool tomoyo_permstr(const char *string, const char *keyword) { const char *cp = strstr(string, keyword); if (cp) return cp == string || *(cp - 1) == '/'; return false; } /** * tomoyo_read_token - Read a word from a line. * * @param: Pointer to "struct tomoyo_acl_param". * * Returns a word on success, "" otherwise. * * To allow the caller to skip NULL check, this function returns "" rather than * NULL if there is no more words to read. */ char *tomoyo_read_token(struct tomoyo_acl_param *param) { char *pos = param->data; char *del = strchr(pos, ' '); if (del) *del++ = '\0'; else del = pos + strlen(pos); param->data = del; return pos; } /** * tomoyo_parse_ulong - Parse an "unsigned long" value. * * @result: Pointer to "unsigned long". * @str: Pointer to string to parse. * * Returns one of values in "enum tomoyo_value_type". * * The @src is updated to point the first character after the value * on success. */ static u8 tomoyo_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 TOMOYO_VALUE_TYPE_INVALID; *str = ep; switch (base) { case 16: return TOMOYO_VALUE_TYPE_HEXADECIMAL; case 8: return TOMOYO_VALUE_TYPE_OCTAL; default: return TOMOYO_VALUE_TYPE_DECIMAL; } } /** * tomoyo_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 tomoyo_print_ulong(char *buffer, const int buffer_len, const unsigned long value, const u8 type) { if (type == TOMOYO_VALUE_TYPE_DECIMAL) snprintf(buffer, buffer_len, "%lu", value); else if (type == TOMOYO_VALUE_TYPE_OCTAL) snprintf(buffer, buffer_len, "0%lo", value); else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL) snprintf(buffer, buffer_len, "0x%lX", value); else snprintf(buffer, buffer_len, "type(%u)", type); } /** * tomoyo_parse_name_union - Parse a tomoyo_name_union. * * @param: Pointer to "struct tomoyo_acl_param". * @ptr: Pointer to "struct tomoyo_name_union". * * Returns true on success, false otherwise. */ bool tomoyo_parse_name_union(struct tomoyo_acl_param *param, struct tomoyo_name_union *ptr) { char *filename; if (param->data[0] == '@') { param->data++; ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP); return ptr->group != NULL; } filename = tomoyo_read_token(param); if (!tomoyo_correct_word(filename)) return false; ptr->filename = tomoyo_get_name(filename); return ptr->filename != NULL; } /** * tomoyo_parse_number_union - Parse a tomoyo_number_union. * * @param: Pointer to "struct tomoyo_acl_param". * @ptr: Pointer to "struct tomoyo_number_union". * * Returns true on success, false otherwise. */ bool tomoyo_parse_number_union(struct tomoyo_acl_param *param, struct tomoyo_number_union *ptr) { char *data; u8 type; unsigned long v; memset(ptr, 0, sizeof(*ptr)); if (param->data[0] == '@') { param->data++; ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP); return ptr->group != NULL; } data = tomoyo_read_token(param); type = tomoyo_parse_ulong(&v, &data); if (type == TOMOYO_VALUE_TYPE_INVALID) return false; ptr->values[0] = v; ptr->value_type[0] = type; if (!*data) { ptr->values[1] = v; ptr->value_type[1] = type; return true; } if (*data++ != '-') return false; type = tomoyo_parse_ulong(&v, &data); if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v) return false; ptr->values[1] = v; ptr->value_type[1] = type; return true; } /** * tomoyo_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. * * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF. * This function verifies that \ooo is in valid range. */ static inline bool tomoyo_byte_range(const char *str) { return *str >= '0' && *str++ <= '3' && *str >= '0' && *str++ <= '7' && *str >= '0' && *str <= '7'; } /** * tomoyo_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 tomoyo_alphabet_char(const char c) { return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'); } /** * tomoyo_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 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3) { return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0'); } /** * tomoyo_valid - Check whether the character is a valid char. * * @c: The character to check. * * Returns true if @c is a valid character, false otherwise. */ static inline bool tomoyo_valid(const unsigned char c) { return c > ' ' && c < 127; } /** * tomoyo_invalid - Check whether the character is an invalid char. * * @c: The character to check. * * Returns true if @c is an invalid character, false otherwise. */ static inline bool tomoyo_invalid(const unsigned char c) { return c && (c <= ' ' || c >= 127); } /** * tomoyo_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 tomoyo_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; } /** * tomoyo_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 tomoyo_normalize_line(unsigned char *buffer) { unsigned char *sp = buffer; unsigned char *dp = buffer; bool first = true; while (tomoyo_invalid(*sp)) sp++; while (*sp) { if (!first) *dp++ = ' '; first = false; while (tomoyo_valid(*sp)) *dp++ = *sp++; while (tomoyo_invalid(*sp)) sp++; } *dp = '\0'; } /** * tomoyo_correct_word2 - Validate a string. * * @string: The string to check. May be 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 tomoyo_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 = tomoyo_make_byte(c, d, e); if (tomoyo_invalid(c)) continue; /* pattern is not \000 */ } goto out; } else if (in_repetition && c == '/') { goto out; } else if (tomoyo_invalid(c)) { goto out; } } if (in_repetition) goto out; return true; out: return false; } /** * tomoyo_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 tomoyo_correct_word(const char *string) { return tomoyo_correct_word2(string, strlen(string)); } /** * tomoyo_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 tomoyo_correct_path(const char *filename) { return *filename == '/' && tomoyo_correct_word(filename); } /** * tomoyo_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 tomoyo_correct_domain(const unsigned char *domainname) { if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN)) goto out; domainname += TOMOYO_ROOT_NAME_LEN; if (!*domainname) return true; if (*domainname++ != ' ') goto out; while (1) { const unsigned char *cp = strchr(domainname, ' '); if (!cp) break; if (*domainname != '/' || !tomoyo_correct_word2(domainname, cp - domainname)) goto out; domainname = cp + 1; } return tomoyo_correct_path(domainname); out: return false; } /** * tomoyo_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 tomoyo_domain_def(const unsigned char *buffer) { return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN); } /** * tomoyo_find_domain - Find a domain by the given name. * * @domainname: The domainname to find. * * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise. * * Caller holds tomoyo_read_lock(). */ struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname) { struct tomoyo_domain_info *domain; struct tomoyo_path_info name; name.name = domainname; tomoyo_fill_path_info(&name); list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) { if (!domain->is_deleted && !tomoyo_pathcmp(&name, domain->domainname)) return domain; } return NULL; } /** * tomoyo_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 tomoyo_const_part_length(const char *filename) { char c; int len = 0; if (!filename) return 0; while ((c = *filename++) != '\0') { 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; } /** * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members. * * @ptr: Pointer to "struct tomoyo_path_info" to fill in. * * The caller sets "struct tomoyo_path_info"->name. */ void tomoyo_fill_path_info(struct tomoyo_path_info *ptr) { const char *name = ptr->name; const int len = strlen(name); ptr->const_len = tomoyo_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); } /** * tomoyo_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 tomoyo_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 (tomoyo_byte_range(filename + 1)) filename += 3; else return false; } break; case '\\': if (c != '\\') return false; if (*++filename != '\\') return false; break; case '+': if (!isdigit(c)) return false; break; case 'x': if (!isxdigit(c)) return false; break; case 'a': if (!tomoyo_alphabet_char(c)) return false; break; case '0': case '1': case '2': case '3': if (c == '\\' && tomoyo_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 (tomoyo_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 (tomoyo_byte_range(filename + i + 1)) i += 3; else break; /* Bad pattern. */ } return false; /* Not matched. */ default: j = 0; c = *pattern; if (c == '$') { while (isdigit(filename[j])) j++; } else if (c == 'X') { while (isxdigit(filename[j])) j++; } else if (c == 'A') { while (tomoyo_alphabet_char(filename[j])) j++; } for (i = 1; i <= j; i++) { if (tomoyo_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; } /** * tomoyo_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 tomoyo_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 = tomoyo_file_matches_pattern2(filename, filename_end, pattern_start, pattern - 2); if (first) result = !result; if (result) return false; first = false; pattern_start = pattern; } result = tomoyo_file_matches_pattern2(filename, filename_end, pattern_start, pattern_end); return first ? result : !result; } /** * tomoyo_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 tomoyo_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 (!tomoyo_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 (!tomoyo_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 (tomoyo_path_matches_pattern2(f, p_delimiter + 1)) return true; f_delimiter = strchr(f, '/'); } while (f_delimiter); return false; /* Not matched. */ } /** * tomoyo_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 tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename, const struct tomoyo_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 !tomoyo_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 tomoyo_path_matches_pattern2(f, p); } /** * tomoyo_get_exe - Get tomoyo_realpath() of current process. * * Returns the tomoyo_realpath() of current process on success, NULL otherwise. * * This function uses kzalloc(), so the caller must call kfree() * if this function didn't return NULL. */ const char *tomoyo_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 = tomoyo_realpath_from_path(&vma->vm_file->f_path); break; } } up_read(&mm->mmap_sem); return cp; } /** * tomoyo_get_mode - Get MAC mode. * * @profile: Profile number. * @index: Index number of functionality. * * Returns mode. */ int tomoyo_get_mode(const u8 profile, const u8 index) { u8 mode; const u8 category = TOMOYO_MAC_CATEGORY_FILE; if (!tomoyo_policy_loaded) return TOMOYO_CONFIG_DISABLED; mode = tomoyo_profile(profile)->config[index]; if (mode == TOMOYO_CONFIG_USE_DEFAULT) mode = tomoyo_profile(profile)->config[category]; if (mode == TOMOYO_CONFIG_USE_DEFAULT) mode = tomoyo_profile(profile)->default_config; return mode & 3; } /** * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members. * * @r: Pointer to "struct tomoyo_request_info" to initialize. * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain(). * @index: Index number of functionality. * * Returns mode. */ int tomoyo_init_request_info(struct tomoyo_request_info *r, struct tomoyo_domain_info *domain, const u8 index) { u8 profile; memset(r, 0, sizeof(*r)); if (!domain) domain = tomoyo_domain(); r->domain = domain; profile = domain->profile; r->profile = profile; r->type = index; r->mode = tomoyo_get_mode(profile, index); return r->mode; } /** * tomoyo_last_word - Get last component of a line. * * @line: A line. * * Returns the last word of a line. */ const char *tomoyo_last_word(const char *name) { const char *cp = strrchr(name, ' '); if (cp) return cp + 1; return name; } /** * tomoyo_warn_log - Print warning or error message on console. * * @r: Pointer to "struct tomoyo_request_info". * @fmt: The printf()'s format string, followed by parameters. */ void tomoyo_warn_log(struct tomoyo_request_info *r, const char *fmt, ...) { /* * Temporarily disabled. * Will be replaced with /sys/kernel/security/tomoyo/audit interface. */ } /** * tomoyo_domain_quota_is_ok - Check for domain's quota. * * @r: Pointer to "struct tomoyo_request_info". * * Returns true if the domain is not exceeded quota, false otherwise. * * Caller holds tomoyo_read_lock(). */ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r) { unsigned int count = 0; struct tomoyo_domain_info *domain = r->domain; struct tomoyo_acl_info *ptr; if (r->mode != TOMOYO_CONFIG_LEARNING) return false; if (!domain) return true; list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) { u16 perm; u8 i; if (ptr->is_deleted) continue; switch (ptr->type) { case TOMOYO_TYPE_PATH_ACL: perm = container_of(ptr, struct tomoyo_path_acl, head) ->perm; break; case TOMOYO_TYPE_PATH2_ACL: perm = container_of(ptr, struct tomoyo_path2_acl, head) ->perm; break; case TOMOYO_TYPE_PATH_NUMBER_ACL: perm = container_of(ptr, struct tomoyo_path_number_acl, head)->perm; break; case TOMOYO_TYPE_MKDEV_ACL: perm = container_of(ptr, struct tomoyo_mkdev_acl, head)->perm; break; default: perm = 1; } for (i = 0; i < 16; i++) if (perm & (1 << i)) count++; } if (count < tomoyo_profile(domain->profile)-> pref[TOMOYO_PREF_MAX_LEARNING_ENTRY]) return true; if (!domain->quota_warned) { domain->quota_warned = true; printk(KERN_WARNING "TOMOYO-WARNING: " "Domain '%s' has too many ACLs to hold. " "Stopped learning mode.\n", domain->domainname->name); } return false; }