(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.
Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.
Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.
This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.
Bump __FreeBSD_version and update UPDATING.
Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)
to optionally have overlapping unit numbers if attached in different
vnets.
At this stage if_loop is the only clonable ifnet class that has been
extended to allow for such overlapping allocation of unit numbers, i.e.
in each vnet it is possible to have a lo0 interface. Other clonable ifnet
classes remain to operate with traditional semantics, i.e. each instance
of a clonable ifnet will be assigned a globally unique unit number,
regardless in which vnet such an ifnet becomes instantiated.
While here, garbage collect unused _lo_list field in struct vnet_net,
as well as improve indentation for #defines in sys/net/vnet.h.
The layout of struct vnet_net has changed, therefore bump
__FreeBSD_version.
This change has no functional impact on nooptions VIMAGE kernel builds.
Reviewed by: bz, brooks
Approved by: julian (mentor)
previously always pointing to the default vnet context, to a
dynamically changing thread-local one. The currvnet context
should be set on entry to networking code via CURVNET_SET() macros,
and reverted to previous state via CURVNET_RESTORE(). Recursions
on curvnet are permitted, though strongly discuouraged.
This change should have no functional impact on nooptions VIMAGE
kernel builds, where CURVNET_* macros expand to whitespace.
The curthread->td_vnet (aka curvnet) variable's purpose is to be an
indicator of the vnet context in which the current network-related
operation takes place, in case we cannot deduce the current vnet
context from any other source, such as by looking at mbuf's
m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc. Moreover, so
far curvnet has turned out to be an invaluable consistency checking
aid: it helps to catch cases when sockets, ifnets or any other
vnet-aware structures may have leaked from one vnet to another.
The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros
was a result of an empirical iterative process, whith an aim to
reduce recursions on CURVNET_SET() to a minimum, while still reducing
the scope of CURVNET_SET() to networking only operations - the
alternative would be calling CURVNET_SET() on each system call entry.
In general, curvnet has to be set in three typicall cases: when
processing socket-related requests from userspace or from within the
kernel; when processing inbound traffic flowing from device drivers
to upper layers of the networking stack, and when executing
timer-driven networking functions.
This change also introduces a DDB subcommand to show the list of all
vnet instances.
Approved by: julian (mentor)
parameter that can specify configuration parameters:
o rev cloner api's to add optional parameter block
o add SIOCCREATE2 that accepts parameter data
o rev vlan support to use new api (maintain old code)
Reviewed by: arch@
order to - for example - apply firewall rules to a whole group of
interfaces. This is required for importing pf from OpenBSD 3.9
Obtained from: OpenBSD (with changes)
Discussed on: -net (back in April)
- In ifc_name2unit(), disallow leading zeroes in a unit.
Exploit: ifconfig lo01 create
- In ifc_name2unit(), properly handle overflows. Otherwise,
either of two local panic()'s can occur, either because
no interface with such a name could be found after it was
successfully created, or because the code will bogusly
assume that it's a wildcard (unit < 0 due to overflow).
Exploit: ifconfig lo<overflowed_integer> create
- Previous revision made the following sequence trigger
a KASSERT() failure in queue(3):
Exploit: ifconfig lo0 destroy; ifconfig lo0 destroy
This is because IFC_IFLIST_REMOVE() is always called
before ifc->ifc_destroy() has been run, not accounting
for the fact that the latter can fail and leave the
interface operating (like is the case for "lo0").
So we ended up calling LIST_REMOVE() twice. We cannot
defer IFC_IFLIST_REMOVE() until after a call to
ifc->ifc_destroy() because the ifnet may have been
removed and its memory has been freed, so recover from
this by re-inserting the ifnet in the cloned interfaces
list if ifc->ifc_destroy() indicates a failure.
softc lists and associated mutex are now unused so these have been removed.
Calling if_clone_detach() will now destroy all the cloned interfaces for the
driver and in most cases is all thats needed to unload.
Idea by: brooks
Reviewed by: brooks
cloner. This ensures that ifc->ifc_units is not prematurely freed in
if_clone_detach() before the clones are destroyed, resulting in memory modified
after free. This could be triggered with if_vlan.
Assert that all cloners have been destroyed when freeing the memory.
Change all simple cloners to destroy their clones with ifc_simple_destroy() on
module unload so the reference count is properly updated. This also cleans up
the interface destroy routines and allows future optimisation.
Discussed with: brooks, pjd, -current
Reviewed by: brooks
panic at kmem_alloc() via malloc(9).
PR: kern/77748
Submitted by: Wojciech A. Koszek
OK'ed by: brooks
Security: local DoS, a sample code in the PR.
MFC after: 3 days
- Split the code out into if_clone.[ch].
- Locked struct if_clone. [1]
- Add a per-cloner match function rather then simply matching names of
the form <name><unit> and <name>.
- Use the match function to allow creation of <interface>.<tag>
vlan interfaces. The old way is preserved unchanged!
- Also the match function to allow creation of stf(4) interfaces named
stf0, stf, or 6to4. This is the only major user visible change in
that "ifconfig stf" creates the interface stf rather then stf0 and
does not print "stf0" to stdout.
- Allow destroy functions to fail so they can refuse to delete
interfaces. Currently, we forbid the deletion of interfaces which
were created in the init function, particularly lo0, pflog0, and
pfsync0. In the case of lo0 this was a panic implementation so it
does not count as a user visiable change. :-)
- Since most interfaces do not need the new functionality, an family of
wrapper functions, ifc_simple_*(), were created to wrap old style
cloner functions.
- The IF_CLONE_INITIALIZER macro is replaced with a new incompatible
IFC_CLONE_INITIALIZER and ifc_simple consumers use IFC_SIMPLE_DECLARE
instead.
Submitted by: Maurycy Pawlowski-Wieronski <maurycy at fouk.org> [1]
Reviewed by: andre, mlaier
Discussed on: net
