cvs commit: src/sbin/ipfw ipfw.8 ipfw2.c src/sys/conf NOTES options src/sys/contrib/ipfilter/netinet ip_fil_freebsd.c src/sys/contrib/pf/net pf.c pf_ioctl.c src/sys/kern init_sysent.c sys_socket.c syscalls.c syscalls.master systrace_args.c ...

From: Julian Elischer <julian_at_FreeBSD.org>
Date: Fri, 9 May 2008 23:03:00 +0000 (UTC)
julian      2008-05-09 23:03:00 UTC

  FreeBSD src repository

  Modified files:
    sbin/ipfw            ipfw.8 ipfw2.c 
    sys/conf             NOTES options 
    sys/contrib/ipfilter/netinet ip_fil_freebsd.c 
    sys/contrib/pf/net   pf.c pf_ioctl.c 
    sys/kern             init_sysent.c sys_socket.c syscalls.c 
                         syscalls.master systrace_args.c 
                         uipc_socket.c vfs_export.c 
    sys/net              if.c if_atmsubr.c if_fwsubr.c if_gif.c 
                         if_gif.h if_gre.c if_gre.h 
                         if_iso88025subr.c if_stf.c if_var.h 
                         radix_mpath.c radix_mpath.h route.c 
                         route.h rtsock.c 
    sys/netatalk         at_extern.h at_proto.c 
    sys/netgraph/netflow netflow.c 
    sys/netinet          if_atm.c if_ether.c in_gif.c in_mcast.c 
                         in_pcb.c in_pcb.h in_rmx.c in_var.h 
                         ip_fastfwd.c ip_fw.h ip_fw2.c ip_icmp.c 
                         ip_input.c ip_mroute.c ip_mroute.h 
                         ip_options.c ip_output.c ip_var.h 
                         raw_ip.c sctp_os_bsd.h tcp_input.c 
                         tcp_subr.c tcp_syncache.c 
    sys/netinet6         in6.c in6_ifattach.c in6_rmx.c nd6_rtr.c 
    sys/netipx           ipx_proto.c 
    sys/nfs4client       nfs4_vfsops.c 
    sys/nfsclient        bootp_subr.c nfs_vfsops.c 
    sys/sys              domain.h mbuf.h proc.h socket.h 
                         socketvar.h syscall.h syscall.mk 
                         sysproto.h 
  Added files:
    usr.sbin/setfib      Makefile setfib.1 setfib.c 
  Log:
  Add code to allow the system to handle multiple routing tables.
  This particular implementation is designed to be fully backwards compatible
  and to be MFC-able to 7.x (and 6.x)
  
  Currently the only protocol that can make use of the multiple tables is IPv4
  Similar functionality exists in OpenBSD and Linux.
  
  From my notes:
  
  -----
  
    One thing where FreeBSD has been falling behind, and which by chance I
    have some time to work on is "policy based routing", which allows
    different
    packet streams to be routed by more than just the destination address.
  
    Constraints:
    ------------
  
    I want to make some form of this available in the 6.x tree
    (and by extension 7.x) , but FreeBSD in general needs it so I might as
    well do it in -current and back port the portions I need.
  
    One of the ways that this can be done is to have the ability to
    instantiate multiple kernel routing tables (which I will now
    refer to as "Forwarding Information Bases" or "FIBs" for political
    correctness reasons). Which FIB a particular packet uses to make
    the next hop decision can be decided by a number of mechanisms.
    The policies these mechanisms implement are the "Policies" referred
    to in "Policy based routing".
  
    One of the constraints I have if I try to back port this work to
    6.x is that it must be implemented as a EXTENSION to the existing
    ABIs in 6.x so that third party applications do not need to be
    recompiled in timespan of the branch.
  
    This first version will not have some of the bells and whistles that
    will come with later versions. It will, for example, be limited to 16
    tables in the first commit.
    Implementation method, Compatible version. (part 1)
    -------------------------------
    For this reason I have implemented a "sufficient subset" of a
    multiple routing table solution in Perforce, and back-ported it
    to 6.x. (also in Perforce though not  always caught up with what I
    have done in -current/P4). The subset allows a number of FIBs
    to be defined at compile time (8 is sufficient for my purposes in 6.x)
    and implements the changes needed to allow IPV4 to use them. I have not
    done the changes for ipv6 simply because I do not need it, and I do not
    have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.
  
    Other protocol families are left untouched and should there be
    users with proprietary protocol families, they should continue to work
    and be oblivious to the existence of the extra FIBs.
  
    To understand how this is done, one must know that the current FIB
    code starts everything off with a single dimensional array of
    pointers to FIB head structures (One per protocol family), each of
    which in turn points to the trie of routes available to that family.
  
    The basic change in the ABI compatible version of the change is to
    extent that array to be a 2 dimensional array, so that
    instead of protocol family X looking at rt_tables[X] for the
    table it needs, it looks at rt_tables[Y][X] when for all
    protocol families except ipv4 Y is always 0.
    Code that is unaware of the change always just sees the first row
    of the table, which of course looks just like the one dimensional
    array that existed before.
  
    The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
    are all maintained, but refer only to the first row of the array,
    so that existing callers in proprietary protocols can continue to
    do the "right thing".
    Some new entry points are added, for the exclusive use of ipv4 code
    called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
    which have an extra argument which refers the code to the correct row.
  
    In addition, there are some new entry points (currently called
    rtalloc_fib() and friends) that check the Address family being
    looked up and call either rtalloc() (and friends) if the protocol
    is not IPv4 forcing the action to row 0 or to the appropriate row
    if it IS IPv4 (and that info is available). These are for calling
    from code that is not specific to any particular protocol. The way
    these are implemented would change in the non ABI preserving code
    to be added later.
  
    One feature of the first version of the code is that for ipv4,
    the interface routes show up automatically on all the FIBs, so
    that no matter what FIB you select you always have the basic
    direct attached hosts available to you. (rtinit() does this
    automatically).
  
    You CAN delete an interface route from one FIB should you want
    to but by default it's there. ARP information is also available
    in each FIB. It's assumed that the same machine would have the
    same MAC address, regardless of which FIB you are using to get
    to it.
  
    This brings us as to how the correct FIB is selected for an outgoing
    IPV4 packet.
  
    Firstly, all packets have a FIB associated with them. if nothing
    has been done to change it, it will be FIB 0. The FIB is changed
    in the following ways.
  
    Packets fall into one of a number of classes.
  
    1/ locally generated packets, coming from a socket/PCB.
       Such packets select a FIB from a number associated with the
       socket/PCB. This in turn is inherited from the process,
       but can be changed by a socket option. The process in turn
       inherits it on fork. I have written a utility call setfib
       that acts a bit like nice..
  
           setfib -3 ping target.example.com # will use fib 3 for ping.
  
       It is an obvious extension to make it a property of a jail
       but I have not done so. It can be achieved by combining the setfib and
       jail commands.
  
    2/ packets received on an interface for forwarding.
       By default these packets would use table 0,
       (or possibly a number settable in a sysctl(not yet)).
       but prior to routing the firewall can inspect them (see below).
       (possibly in the future you may be able to associate a FIB
       with packets received on an interface..  An ifconfig arg, but not yet.)
  
    3/ packets inspected by a packet classifier, which can arbitrarily
       associate a fib with it on a packet by packet basis.
       A fib assigned to a packet by a packet classifier
       (such as ipfw) would over-ride a fib associated by
       a more default source. (such as cases 1 or 2).
  
    4/ a tcp listen socket associated with a fib will generate
       accept sockets that are associated with that same fib.
  
    5/ Packets generated in response to some other packet (e.g. reset
       or icmp packets). These should use the FIB associated with the
       packet being reponded to.
  
    6/ Packets generated during encapsulation.
       gif, tun and other tunnel interfaces will encapsulate using the FIB
       that was in effect withthe proces that set up the tunnel.
       thus setfib 1 ifconfig gif0 [tunnel instructions]
       will set the fib for the tunnel to use to be fib 1.
  
    Routing messages would be associated with their
    process, and thus select one FIB or another.
    messages from the kernel would be associated with the fib they
    refer to and would only be received by a routing socket associated
    with that fib. (not yet implemented)
  
    In addition Netstat has been edited to be able to cope with the
    fact that the array is now 2 dimensional. (It looks in system
    memory using libkvm (!)). Old versions of netstat see only the first FIB.
  
    In addition two sysctls are added to give:
    a) the number of FIBs compiled in (active)
    b) the default FIB of the calling process.
  
    Early testing experience:
    -------------------------
  
    Basically our (IronPort's) appliance does this functionality already
    using ipfw fwd but that method has some drawbacks.
  
    For example,
    It can't fully simulate a routing table because it can't influence the
    socket's choice of local address when a connect() is done.
  
    Testing during the generating of these changes has been
    remarkably smooth so far. Multiple tables have co-existed
    with no notable side effects, and packets have been routes
    accordingly.
  
    ipfw has grown 2 new keywords:
  
    setfib N ip from anay to any
    count ip from any to any fib N
  
    In pf there seems to be a requirement to be able to give symbolic names to the
    fibs but I do not have that capacity. I am not sure if it is required.
  
    SCTP has interestingly enough built in support for this, called VRFs
    in Cisco parlance. it will be interesting to see how that handles it
    when it suddenly actually does something.
  
    Where to next:
    --------------------
  
    After committing the ABI compatible version and MFCing it, I'd
    like to proceed in a forward direction in -current. this will
    result in some roto-tilling in the routing code.
  
    Firstly: the current code's idea of having a separate tree per
    protocol family, all of the same format, and pointed to by the
    1 dimensional array is a bit silly. Especially when one considers that
    there is code that makes assumptions about every protocol having the
    same internal structures there. Some protocols don't WANT that
    sort of structure. (for example the whole idea of a netmask is foreign
    to appletalk). This needs to be made opaque to the external code.
  
    My suggested first change is to add routing method pointers to the
    'domain' structure, along with information pointing the data.
    instead of having an array of pointers to uniform structures,
    there would be an array pointing to the 'domain' structures
    for each protocol address domain (protocol family),
    and the methods this reached would be called. The methods would have
    an argument that gives FIB number, but the protocol would be free
    to ignore it.
  
    When the ABI can be changed it raises the possibilty of the
    addition of a fib entry into the "struct route". Currently,
    the structure contains the sockaddr of the desination, and the resulting
    fib entry. To make this work fully, one could add a fib number
    so that given an address and a fib, one can find the third element, the
    fib entry.
  
    Interaction with the ARP layer/ LL layer would need to be
    revisited as well. Qing Li has been working on this already.
  
    This work was sponsored by Ironport Systems/Cisco
  
  Reviewed by:    several including rwatson, bz and mlair (parts each)
  Obtained from:  Ironport systems/Cisco
  
  Revision  Changes    Path
  1.212     +12 -0     src/sbin/ipfw/ipfw.8
  1.119     +37 -2     src/sbin/ipfw/ipfw2.c
  1.1485    +2 -0      src/sys/conf/NOTES
  1.628     +1 -0      src/sys/conf/options
  1.10      +2 -2      src/sys/contrib/ipfilter/netinet/ip_fil_freebsd.c
  1.54      +32 -4     src/sys/contrib/pf/net/pf.c
  1.32      +2 -2      src/sys/contrib/pf/net/pf_ioctl.c
  1.240     +1 -1      src/sys/kern/init_sysent.c
  1.76      +1 -1      src/sys/kern/sys_socket.c
  1.224     +1 -1      src/sys/kern/syscalls.c
  1.243     +1 -1      src/sys/kern/syscalls.master
  1.24      +7 -0      src/sys/kern/systrace_args.c
  1.310     +20 -0     src/sys/kern/uipc_socket.c
  1.342     +16 -3     src/sys/kern/vfs_export.c
  1.279     +6 -3      src/sys/net/if.c
  1.47      +2 -1      src/sys/net/if_atmsubr.c
  1.26      +1 -1      src/sys/net/if_fwsubr.c
  1.69      +3 -0      src/sys/net/if_gif.c
  1.20      +1 -0      src/sys/net/if_gif.h
  1.48      +6 -1      src/sys/net/if_gre.c
  1.14      +1 -0      src/sys/net/if_gre.h
  1.78      +2 -1      src/sys/net/if_iso88025subr.c
  1.62      +7 -2      src/sys/net/if_stf.c
  1.118     +2 -0      src/sys/net/if_var.h
  1.5       +2 -2      src/sys/net/radix_mpath.c
  1.2       +2 -1      src/sys/net/radix_mpath.h
  1.129     +390 -128  src/sys/net/route.c
  1.70      +31 -4     src/sys/net/route.h
  1.146     +9 -5      src/sys/net/rtsock.c
  1.19      +1 -0      src/sys/netatalk/at_extern.h
  1.14      +1 -1      src/sys/netatalk/at_proto.c
  1.29      +4 -2      src/sys/netgraph/netflow/netflow.c
  1.22      +1 -1      src/sys/netinet/if_atm.c
  1.171     +180 -117  src/sys/netinet/if_ether.c
  1.39      +6 -2      src/sys/netinet/in_gif.c
  1.5       +2 -1      src/sys/netinet/in_mcast.c
  1.206     +2 -1      src/sys/netinet/in_pcb.c
  1.106     +1 -1      src/sys/netinet/in_pcb.h
  1.59      +126 -28   src/sys/netinet/in_rmx.c
  1.62      +16 -0     src/sys/netinet/in_var.h
  1.42      +1 -1      src/sys/netinet/ip_fastfwd.c
  1.114     +4 -0      src/sys/netinet/ip_fw.h
  1.186     +48 -6     src/sys/netinet/ip_fw2.c
  1.123     +12 -5     src/sys/netinet/ip_icmp.c
  1.336     +5 -5      src/sys/netinet/ip_input.c
  1.139     +2 -2      src/sys/netinet/ip_mroute.c
  1.32      +1 -1      src/sys/netinet/ip_mroute.h
  1.10      +3 -2      src/sys/netinet/ip_options.c
  1.283     +5 -3      src/sys/netinet/ip_output.c
  1.102     +1 -1      src/sys/netinet/ip_var.h
  1.184     +1 -1      src/sys/netinet/raw_ip.c
  1.34      +1 -1      src/sys/netinet/sctp_os_bsd.h
  1.376     +1 -0      src/sys/netinet/tcp_input.c
  1.306     +7 -1      src/sys/netinet/tcp_subr.c
  1.145     +4 -0      src/sys/netinet/tcp_syncache.c
  1.79      +2 -1      src/sys/netinet6/in6.c
  1.42      +3 -3      src/sys/netinet6/in6_ifattach.c
  1.21      +8 -4      src/sys/netinet6/in6_rmx.c
  1.39      +2 -1      src/sys/netinet6/nd6_rtr.c
  1.23      +11 -1     src/sys/netipx/ipx_proto.c
  1.34      +2 -1      src/sys/nfs4client/nfs4_vfsops.c
  1.71      +3 -2      src/sys/nfsclient/bootp_subr.c
  1.205     +1 -0      src/sys/nfsclient/nfs_vfsops.c
  1.23      +6 -0      src/sys/sys/domain.h
  1.226     +20 -2     src/sys/sys/mbuf.h
  1.513     +1 -0      src/sys/sys/proc.h
  1.100     +1 -0      src/sys/sys/socket.h
  1.163     +1 -0      src/sys/sys/socketvar.h
  1.221     +1 -0      src/sys/sys/syscall.h
  1.176     +1 -0      src/sys/sys/syscall.mk
  1.225     +5 -0      src/sys/sys/sysproto.h
  1.1       +6 -0      src/usr.sbin/setfib/Makefile (new)
  1.1       +92 -0     src/usr.sbin/setfib/setfib.1 (new)
  1.1       +103 -0    src/usr.sbin/setfib/setfib.c (new)
Received on Fri May 09 2008 - 23:03:01 UTC