diff options
Diffstat (limited to 'security/tomoyo/domain.c')
| -rw-r--r-- | security/tomoyo/domain.c | 192 |
1 files changed, 185 insertions, 7 deletions
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c index eb75401fd6b..1d8b1696057 100644 --- a/security/tomoyo/domain.c +++ b/security/tomoyo/domain.c @@ -19,11 +19,63 @@ /* The initial domain. */ struct tomoyo_domain_info tomoyo_kernel_domain; -/* The list for "struct tomoyo_domain_info". */ +/* + * tomoyo_domain_list is used for holding list of domains. + * The ->acl_info_list of "struct tomoyo_domain_info" is used for holding + * permissions (e.g. "allow_read /lib/libc-2.5.so") given to each domain. + * + * An entry is added by + * + * # ( echo "<kernel>"; echo "allow_execute /sbin/init" ) > \ + * /sys/kernel/security/tomoyo/domain_policy + * + * and is deleted by + * + * # ( echo "<kernel>"; echo "delete allow_execute /sbin/init" ) > \ + * /sys/kernel/security/tomoyo/domain_policy + * + * and all entries are retrieved by + * + * # cat /sys/kernel/security/tomoyo/domain_policy + * + * A domain is added by + * + * # echo "<kernel>" > /sys/kernel/security/tomoyo/domain_policy + * + * and is deleted by + * + * # echo "delete <kernel>" > /sys/kernel/security/tomoyo/domain_policy + * + * and all domains are retrieved by + * + * # grep '^<kernel>' /sys/kernel/security/tomoyo/domain_policy + * + * Normally, a domainname is monotonically getting longer because a domainname + * which the process will belong to if an execve() operation succeeds is + * defined as a concatenation of "current domainname" + "pathname passed to + * execve()". + * See tomoyo_domain_initializer_list and tomoyo_domain_keeper_list for + * exceptions. + */ LIST_HEAD(tomoyo_domain_list); DECLARE_RWSEM(tomoyo_domain_list_lock); -/* Structure for "initialize_domain" and "no_initialize_domain" keyword. */ +/* + * tomoyo_domain_initializer_entry is a structure which is used for holding + * "initialize_domain" and "no_initialize_domain" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_domain_initializer_list . + * (2) "domainname" which is "a domainname" or "the last component of a + * domainname". This field is NULL if "from" clause is not specified. + * (3) "program" which is a program's pathname. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + * (5) "is_not" is a bool which is true if "no_initialize_domain", false + * otherwise. + * (6) "is_last_name" is a bool which is true if "domainname" is "the last + * component of a domainname", false otherwise. + */ struct tomoyo_domain_initializer_entry { struct list_head list; const struct tomoyo_path_info *domainname; /* This may be NULL */ @@ -34,7 +86,23 @@ struct tomoyo_domain_initializer_entry { bool is_last_name; }; -/* Structure for "keep_domain" and "no_keep_domain" keyword. */ +/* + * tomoyo_domain_keeper_entry is a structure which is used for holding + * "keep_domain" and "no_keep_domain" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_domain_keeper_list . + * (2) "domainname" which is "a domainname" or "the last component of a + * domainname". + * (3) "program" which is a program's pathname. + * This field is NULL if "from" clause is not specified. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + * (5) "is_not" is a bool which is true if "no_initialize_domain", false + * otherwise. + * (6) "is_last_name" is a bool which is true if "domainname" is "the last + * component of a domainname", false otherwise. + */ struct tomoyo_domain_keeper_entry { struct list_head list; const struct tomoyo_path_info *domainname; @@ -45,7 +113,16 @@ struct tomoyo_domain_keeper_entry { bool is_last_name; }; -/* Structure for "alias" keyword. */ +/* + * tomoyo_alias_entry is a structure which is used for holding "alias" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_alias_list . + * (2) "original_name" which is a dereferenced pathname. + * (3) "aliased_name" which is a symlink's pathname. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + */ struct tomoyo_alias_entry { struct list_head list; const struct tomoyo_path_info *original_name; @@ -92,7 +169,42 @@ const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain) return cp0; } -/* The list for "struct tomoyo_domain_initializer_entry". */ +/* + * tomoyo_domain_initializer_list is used for holding list of programs which + * triggers reinitialization of domainname. Normally, a domainname is + * monotonically getting longer. But sometimes, we restart daemon programs. + * It would be convenient for us that "a daemon started upon system boot" and + * "the daemon restarted from console" belong to the same domain. Thus, TOMOYO + * provides a way to shorten domainnames. + * + * An entry is added by + * + * # echo 'initialize_domain /usr/sbin/httpd' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and is deleted by + * + * # echo 'delete initialize_domain /usr/sbin/httpd' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and all entries are retrieved by + * + * # grep ^initialize_domain /sys/kernel/security/tomoyo/exception_policy + * + * In the example above, /usr/sbin/httpd will belong to + * "<kernel> /usr/sbin/httpd" domain. + * + * You may specify a domainname using "from" keyword. + * "initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd" + * will cause "/usr/sbin/httpd" executed from "<kernel> /etc/rc.d/init.d/httpd" + * domain to belong to "<kernel> /usr/sbin/httpd" domain. + * + * You may add "no_" prefix to "initialize_domain". + * "initialize_domain /usr/sbin/httpd" and + * "no_initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd" + * will cause "/usr/sbin/httpd" to belong to "<kernel> /usr/sbin/httpd" domain + * unless executed from "<kernel> /etc/rc.d/init.d/httpd" domain. + */ static LIST_HEAD(tomoyo_domain_initializer_list); static DECLARE_RWSEM(tomoyo_domain_initializer_list_lock); @@ -268,7 +380,44 @@ static bool tomoyo_is_domain_initializer(const struct tomoyo_path_info * return flag; } -/* The list for "struct tomoyo_domain_keeper_entry". */ +/* + * tomoyo_domain_keeper_list is used for holding list of domainnames which + * suppresses domain transition. Normally, a domainname is monotonically + * getting longer. But sometimes, we want to suppress domain transition. + * It would be convenient for us that programs executed from a login session + * belong to the same domain. Thus, TOMOYO provides a way to suppress domain + * transition. + * + * An entry is added by + * + * # echo 'keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and is deleted by + * + * # echo 'delete keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and all entries are retrieved by + * + * # grep ^keep_domain /sys/kernel/security/tomoyo/exception_policy + * + * In the example above, any process which belongs to + * "<kernel> /usr/sbin/sshd /bin/bash" domain will remain in that domain, + * unless explicitly specified by "initialize_domain" or "no_keep_domain". + * + * You may specify a program using "from" keyword. + * "keep_domain /bin/pwd from <kernel> /usr/sbin/sshd /bin/bash" + * will cause "/bin/pwd" executed from "<kernel> /usr/sbin/sshd /bin/bash" + * domain to remain in "<kernel> /usr/sbin/sshd /bin/bash" domain. + * + * You may add "no_" prefix to "keep_domain". + * "keep_domain <kernel> /usr/sbin/sshd /bin/bash" and + * "no_keep_domain /usr/bin/passwd from <kernel> /usr/sbin/sshd /bin/bash" will + * cause "/usr/bin/passwd" to belong to + * "<kernel> /usr/sbin/sshd /bin/bash /usr/bin/passwd" domain, unless + * explicitly specified by "initialize_domain". + */ static LIST_HEAD(tomoyo_domain_keeper_list); static DECLARE_RWSEM(tomoyo_domain_keeper_list_lock); @@ -437,7 +586,36 @@ static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname, return flag; } -/* The list for "struct tomoyo_alias_entry". */ +/* + * tomoyo_alias_list is used for holding list of symlink's pathnames which are + * allowed to be passed to an execve() request. Normally, the domainname which + * the current process will belong to after execve() succeeds is calculated + * using dereferenced pathnames. But some programs behave differently depending + * on the name passed to argv[0]. For busybox, calculating domainname using + * dereferenced pathnames will cause all programs in the busybox to belong to + * the same domain. Thus, TOMOYO provides a way to allow use of symlink's + * pathname for checking execve()'s permission and calculating domainname which + * the current process will belong to after execve() succeeds. + * + * An entry is added by + * + * # echo 'alias /bin/busybox /bin/cat' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and is deleted by + * + * # echo 'delete alias /bin/busybox /bin/cat' > \ + * /sys/kernel/security/tomoyo/exception_policy + * + * and all entries are retrieved by + * + * # grep ^alias /sys/kernel/security/tomoyo/exception_policy + * + * In the example above, if /bin/cat is a symlink to /bin/busybox and execution + * of /bin/cat is requested, permission is checked for /bin/cat rather than + * /bin/busybox and domainname which the current process will belong to after + * execve() succeeds is calculated using /bin/cat rather than /bin/busybox . + */ static LIST_HEAD(tomoyo_alias_list); static DECLARE_RWSEM(tomoyo_alias_list_lock); |