Eric Blake 901af5f469 build: more workarounds for if_bridge.h
This is a second attempt at fixing the problem first attempted
in commit 2df8d99; basically undoing the fact that it was
reverted in commit 43cee32f, plus fixing two more issues: the
code in configure.ac has to EXACTLY match virnetdevbridge.c
with regards to declaring in6 types before using if_bridge.h,
and the fact that RHEL 5 has even more conflicts:

In file included from util/virnetdevbridge.c:49:
/usr/include/linux/in6.h:47: error: conflicting types for 'in6addr_any'
/usr/include/netinet/in.h:206: error: previous declaration of 'in6addr_any' was here
/usr/include/linux/in6.h:49: error: conflicting types for 'in6addr_loopback'
/usr/include/netinet/in.h:207: error: previous declaration of 'in6addr_loopback' was here

The rest of this commit message borrows from the original try
of 2df8d99:

A fresh checkout on a RHEL 6 machine with these packages:
kernel-headers-2.6.32-405.el6.x86_64
glibc-2.12-1.128.el6.x86_64
failed to configure with this message:
checking for linux/if_bridge.h... no
configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support

Digging in config.log, we see that the problem is identical to
what we fixed earlier in commit d12c2811:

configure:98831: checking for linux/if_bridge.h
configure:98853: gcc -std=gnu99 -c -g -O2  conftest.c >&5
In file included from /usr/include/linux/if_bridge.h:17,
                 from conftest.c:559:
/usr/include/linux/in6.h:31: error: redefinition of 'struct in6_addr'
/usr/include/linux/in6.h:48: error: redefinition of 'struct sockaddr_in6'
/usr/include/linux/in6.h:56: error: redefinition of 'struct ipv6_mreq'
configure:98860: $? = 1

I had not hit it earlier because I was using incremental builds,
where config.cache had shielded me from the kernel-headers breakage.

* configure.ac (if_bridge.h): Avoid conflicting type definitions.
* src/util/virnetdevbridge.c (includes): Also sanitize for RHEL 5.

Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 70024dc9192038575ab5217ac35080b038e5b13e)

Done in one patch rather than a series for bisectability reasons
(as intermediate patches suffer from various problems on various
platforms), and because the intermediate patches include a revert,
but it is pointless to backport two patches where one undoes the
other.  Intermediate patches include: 9a2f36e, c308a9a, 1bf661c,
d12c281, 2df8d99, 43cee32 (phew, that's a mouthful).

Conflicts:
	configure.ac - skip the churn of all intermediate patches
	src/util/virnetdevbridge.c - ditto
2013-09-18 16:55:49 -06:00
..
2012-04-09 10:21:07 -06:00
2012-05-04 10:42:09 -04:00
2012-02-24 16:49:21 -07:00
2012-05-03 14:59:57 -06:00

       libvirt library code README
       ===========================

The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.

The files directly in this directory are supporting the public API
entry points & data structures.

There are two core shared modules to be aware of:

 * util/  - a collection of shared APIs that can be used by any
            code. This directory is always in the include path
            for all things built

 * conf/  - APIs for parsing / manipulating all the official XML
            files used by the public API. This directory is only
            in the include path for driver implementation modules

 * vmx/   - VMware VMX config handling (used by esx/ and vmware/)


Then there are the hypervisor implementations:

 * esx/          - VMware ESX and GSX support using vSphere API over SOAP
 * hyperv/       - Microsoft Hyper-V support using WinRM
 * lxc/          - Linux Native Containers
 * openvz/       - OpenVZ containers using cli tools
 * phyp/         - IBM Power Hypervisor using CLI tools over SSH
 * qemu/         - QEMU / KVM using qemu CLI/monitor
 * remote/       - Generic libvirt native RPC client
 * test/         - A "mock" driver for testing
 * uml/          - User Mode Linux
 * vbox/         - Virtual Box using native API
 * vmware/       - VMware Workstation and Player using the vmrun tool
 * xen/          - Xen using hypercalls, XenD SEXPR & XenStore
 * xenapi/       - Xen using libxenserver


Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU, UML and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly

 * cpu/          - CPU feature management
 * interface/    - Host network interface management
 * network/      - Virtual NAT networking
 * nwfilter/     - Network traffic filtering rules
 * node_device/  - Host device enumeration
 * secret/       - Secret management
 * security/     - Mandatory access control drivers
 * storage/      - Storage management drivers


Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories