Older version of liblxc only allowed for 105 bytes to be used for the abstract
unix domain socket name because the code for our abstract unix socket handling
performed invalid checks. Since we \0-terminate we could now have a maximum of
106 chars. But do not break backwards compatibility we keep the limit at 105.
Reported-by: 0x0916 w@laoqinren.net
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
In case the lxc command socket is hashed and the socket was created for a
different path than the one we're currently querying
lxc_cmd_get_{lxcpath,name}() can return NULL. The command socket path is hashed
when len(lxcpath) > sizeof(sun_path) - 2.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
lxc_cmd_get_lxcpath() and lxc_cmd_get_name() both pass a nil pointer to
fill_sock_name(). Make sure that they are not dereferenced.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Abstract unix sockets need not be \0-terminated. So you can effectively have
107 chars available. If you \0-terminate you'll have a 106. Don't enforce
\0-termination in these low-level functions. Enforce it higher up which we
already do.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This adds lxc_config_item_is_supported() as API extension. It allows to check
whether a given config item (e.g. lxc.autodev) is supported by this LXC
instance. The function is useful in the following scenarios:
1. Users have compiled liblxc from source and have removed a config items from
the corresponding struct in confile.c. (For example, embedded users might
decide to gut a bunch of options that they cannot use.)
2. Callers that want to check for a specific configuration item independent of
the version numbers exposed in our version.h header.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This left the file descriptor to the underlying /dev/ptmx file open which
confused the hell out of criu. Let's close it.
Closes https://github.com/lxc/lxd/issues/3243.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
In a lot of cases we need a list of the writeable cgroup controllers detected
by the cgfsng driver.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Use the loop device helpers I wrote for LXD in LXC as well. They should be more
efficient.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The new{g,u}idmap binaries where a source of trouble for users when they lacked
sufficient privileges. This commit adds code to check for sufficient privilege.
It checks whether new{g,u}idmap is root owned and has the setuid bit set and if
it doesn't it checks whether new{g,u}idmap is root owned and has CAP_SETUID in
its CAP_PERMITTED and CAP_EFFECTIVE set.
Closes#296.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Add two new helpers that allow to determine whether a given proc or file has a
capability in the given set and move lxc_cap_is_set() to static function that
both call internally.
Closes#296.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
