[PATCHES] misc networking, sysctl, other

[David van Moolenbroek]

A few somewhat related patches, mostly some more post-3.4.0 preparation, mostly for the larger upcoming changes to the network stack.

The biggest change here is RMIB. Currently, the MIB service implements the entire sysctl tree itself, but this is not always convenient: in some cases, it is better to put the handling of certain sysctl nodes in the service that is also responsible for the functionality that those nodes are about. Proper separation of concerns and all that. The RMIB addition here allows for that: a service can now "mount" a part of the sysctl tree into the central tree maintained by the MIB service, similar to file system mounting. Once a server has mounted a sysctl subtree through RMIB, the MIB service will call it to handle any sysctl(2) user requests affecting that subtree. In general, RMIB is fairly heavy-weight solution and should only be used when the benefits outweight the costs (extra communication, extra code, extra resource usage, various limitations). However, the two subsequent patches in this set show two use cases for it: the SysV IPC service taking over responsibility of the "kern.ipc" subtree and INET/LWIP adding "net.route" to the tree. The latter is preparation to allow us to switch painlessly to the NetBSD libc version of getifaddrs(3) after 3.4.0.

Regards,
David

http://gerrit.minix3.org/#/c/3327/ - INET/LWIP: minimal net.route sysctl support
http://gerrit.minix3.org/#/c/3326/ - IPC: use RMIB to handle kern.ipc sysctl subtree
http://gerrit.minix3.org/#/c/3325/ - MIB/libsys: support for remote MIB (RMIB) subtrees
http://gerrit.minix3.org/#/c/3324/ - Do not hide the MSG_NOSIGNAL flag
http://gerrit.minix3.org/#/c/3323/ - LWIP: fix system.conf file
http://gerrit.minix3.org/#/c/3322/ - Import a subset of PF distribution files
http://gerrit.minix3.org/#/c/3321/ - Import additional networking headers from NetBSD
http://gerrit.minix3.org/#/c/3320/ - libchardriver: make some pointers constant