fdb3bde31c
A future patch wants the DAC security manager to be able to safely get the supplemental group list for a given uid, but at the time of a fork rather than during initialization so as to pick up on live changes to the system's group database. This patch adds the framework, including the possibility of a pre-fork callback failing. For now, any driver that implements a prefork callback must be robust against the possibility of being part of a security stack where a later element in the chain fails prefork. This means that drivers cannot do any action that requires a call to postfork for proper cleanup (no grabbing a mutex, for example). If this is too prohibitive in the future, we would have to switch to a transactioning sequence, where each driver has (up to) 3 callbacks: PreForkPrepare, PreForkCommit, and PreForkAbort, to either clean up or commit changes made during prepare. * src/security/security_driver.h (virSecurityDriverPreFork): New callback. * src/security/security_manager.h (virSecurityManagerPreFork): Change signature. * src/security/security_manager.c (virSecurityManagerPreFork): Optionally call into driver, and allow returning failure. * src/security/security_stack.c (virSecurityDriverStack): Wrap the handler for the stack driver. * src/qemu/qemu_process.c (qemuProcessStart): Adjust caller. Signed-off-by: Eric Blake <eblake@redhat.com>
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>