mirror of
https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git
synced 2026-03-31 06:30:41 +02:00
read-only mirror of https://gitlab.freedesktop.org/NetworkManager/NetworkManager
9440eefb6d
Rework platform object cache to use NMDedupMultiIndex. Already previously, NMPCache used NMMultiIndex and had thus O(1) for most operations. What is new is: - Contrary to NMMultiIndex, NMDedupMultiIndex preserves the order of the cached items. That is crucial to handle routes properly as kernel will replace the first matching route based on network/plen/metric properties. See related bug rh#1337855. Without tracking the order of routes as they are exposed by kernel, we cannot properly maintain the route cache. - All NMPObject instances are now treated immutable, refcounted and get de-duplicated via NMDedupMultiIndex. This allows to have a global NMDedupMultiIndex that can be shared with NMIP4Config and NMRouteManager. It also allows to share the objects themselves. Immutable objects are so much nicer. We can get rid of the update pre-hook callback, which was required previously because we would mutate the object inplace. Now, we can just update the cache, and compare obj_old and obj_new after the fact. - NMMultiIndex was treated as an internal of NMPCache. On the other hand, NMDedupMultiIndex exposes NMDedupMultiHeadEntry, which is basically an object that allows to iterate over all related objects. That means, we can now lookup objects in the cache and give the NMDedupMultiHeadEntry instance to the caller, which then can iterate the list on it's own -- without need for copying anything. Currently, at various places we still create copies of lookup results. That can be improved later. The ability to share NMPObject instances should enable us to significantly improve performance and scale with large number of routes. Of course there is a memory overhead of having an index for each list entry. Each NMPObject may also require an NMDedupMultiEntry, NMDedupMultiHeadEntry, and NMDedupMultiBox item, which are tracked in a GHashTable. Optimally, one NMDedupMultiHeadEntry is the head for multiple objects, and NMDedupMultiBox is able to deduplicate several NMPObjects, so that there is a net saving. Also, each object type has several indexes of type NMPCacheIdType. So, worst case an NMPlatformIP4Route in the platform cache is tracked by 8 NMPCacheIdType indexes, for each we require a NMDedupMultiEntry, plus the shared NMDedupMultiHeadEntry. The NMDedupMultiBox instance is shared between the 8 indexes (and possibly other). |
||
|---|---|---|
| clients | ||
| contrib | ||
| data | ||
| dispatcher | ||
| docs | ||
| examples | ||
| introspection | ||
| libnm | ||
| libnm-core | ||
| libnm-glib | ||
| libnm-util | ||
| m4 | ||
| man | ||
| po | ||
| shared | ||
| src | ||
| tools | ||
| vapi | ||
| .dir-locals.el | ||
| .gitignore | ||
| .travis.yml | ||
| AUTHORS | ||
| autogen.sh | ||
| ChangeLog | ||
| configure.ac | ||
| CONTRIBUTING | ||
| COPYING | ||
| linker-script-binary.ver | ||
| linker-script-devices.ver | ||
| linker-script-settings.ver | ||
| MAINTAINERS | ||
| Makefile.am | ||
| Makefile.examples | ||
| Makefile.glib | ||
| Makefile.vapigen | ||
| NetworkManager.pc.in | ||
| NEWS | ||
| README | ||
| TODO | ||
| valgrind.suppressions | ||
| zanata.xml | ||
****************** 2008-12-11: NetworkManager core daemon has moved to git.freedesktop.org! git clone git://git.freedesktop.org/git/NetworkManager/NetworkManager.git ****************** Networking that Just Works -------------------------- NetworkManager attempts to keep an active network connection available at all times. The point of NetworkManager is to make networking configuration and setup as painless and automatic as possible. NetworkManager is intended to replace default route, replace other routes, set IP addresses, and in general configure networking as NM sees fit (with the possibility of manual override as necessary). In effect, the goal of NetworkManager is to make networking Just Work with a minimum of user hassle, but still allow customization and a high level of manual network control. If you have special needs, we'd like to hear about them, but understand that NetworkManager is not intended for every use-case. NetworkManager will attempt to keep every network device in the system up and active, as long as the device is available for use (has a cable plugged in, the killswitch isn't turned on, etc). Network connections can be set to 'autoconnect', meaning that NetworkManager will make that connection active whenever it and the hardware is available. "Settings services" store lists of user- or administrator-defined "connections", which contain all the settings and parameters required to connect to a specific network. NetworkManager will _never_ activate a connection that is not in this list, or that the user has not directed NetworkManager to connect to. How it works: The NetworkManager daemon runs as a privileged service (since it must access and control hardware), but provides a D-Bus interface on the system bus to allow for fine-grained control of networking. NetworkManager does not store connections or settings, it is only the mechanism by which those connections are selected and activated. To store pre-defined network connections, two separate services, the "system settings service" and the "user settings service" store connection information and provide these to NetworkManager, also via D-Bus. Each settings service can determine how and where it persistently stores the connection information; for example, the GNOME applet stores its configuration in GConf, and the system settings service stores it's config in distro-specific formats, or in a distro- agnostic format, depending on user/administrator preference. A variety of other system services are used by NetworkManager to provide network functionality: wpa_supplicant for wireless connections and 802.1x wired connections, pppd for PPP and mobile broadband connections, DHCP clients for dynamic IP addressing, dnsmasq for proxy nameserver and DHCP server functionality for internet connection sharing, and avahi-autoipd for IPv4 link-local addresses. Most communication with these daemons occurs, again, via D-Bus. Why doesn't my network Just Work? Driver problems are the #1 cause of why NetworkManager sometimes fails to connect to wireless networks. Often, the driver simply doesn't behave in a consistent manner, or is just plain buggy. NetworkManager supports _only_ those drivers that are shipped with the upstream Linux kernel, because only those drivers can be easily fixed and debugged. ndiswrapper, vendor binary drivers, or other out-of-tree drivers may or may not work well with NetworkManager, precisely because they have not been vetted and improved by the open-source community, and because problems in these drivers usually cannot be fixed. Sometimes, command-line tools like 'iwconfig' will work, but NetworkManager will fail. This is again often due to buggy drivers, because these drivers simply aren't expecting the dynamic requests that NetworkManager and wpa_supplicant make. Driver bugs should be filed in the bug tracker of the distribution being run, since often distributions customize their kernel and drivers. Sometimes, it really is NetworkManager's fault. If you think that's the case, please file a bug at http://bugzilla.gnome.org and choose the NetworkManager component. Attaching the output of /var/log/messages or /var/log/daemon.log (wherever your distribution directs syslog's 'daemon' facility output) is often very helpful, and (if you can get) a working wpa_supplicant config file helps enormously.