Previously, ppp attempted to bind() to a local domain tcp socket
based on the peer authname & enddisc. If it succeeded, it listen()ed
and became MP server. If it failed, it connect()ed and became MP
client. The server then select()ed on the descriptor, accept()ed
it and wrote its pid to it then read the link data & link file descriptor,
and finally sent an ack (``!''). The client would read() the server
pid, transfer the link lock to that pid, send the link data & descriptor
and read the ack. It would then close the descriptor and clean up.
There was a race between the bind() and listen() where someone could
attempt to connect() and fail.
This change removes the race. Now ppp makes the RCVBUF big enough on a
socket descriptor and attempts to bind() to a local domain *udp* socket
(same name as before). If it succeeds, it becomes MP server. If it
fails, it sets the SNDBUF and connect()s, becoming MP client. The server
select()s on the descriptor and recvmsg()s the message, insisting on at
least two descriptors (plus the link data). It uses the second descriptor
to write() its pid then read()s an ack (``!''). The client creates a
socketpair() and sendmsg()s the link data, link descriptor and one of
the socketpair descriptors. It then read()s the server pid from the
other socketpair descriptor, transfers any locks and write()s an ack.
Now, there can be no race, and a connect() failure indicates a stale
socket file.
This also fixes MP ppp over ethernet, where the struct msghdr was being
misconstructed when transferring the control socket descriptor.
Also, if we fail to send the link, don't hang around in a ``session
owner'' state, just do the setsid() and fork() if it's required to
disown a tty.
UDP idea suggested by: Chris Bennet from Mindspring at FreeBSDCon
0.81.1 of the i4b code - namely support of the I4B_VR_REQ
ioctl via the i4brbchX device.
Ppp controls the phone number, but idle timers and
SYNC/RAW decisions are still made by isdnd (in isdnd.rc).
This involves a new datalink state machine phase. The
``wait for carrier'' phase happens after dialing but
before logging in. The whole dial state should really
be abstracted so that each device type can deal with it
in its own way (thinking about PPPoE) - but that'll have
to wait.
The ``set cd'' symantics remain the same for tty devices,
but we now delay until we either get CD or timeout waiting
(at which time we drop the link if we require CD).
For i4b devices we always insist on carrier.
Thanks to hm@ for his help, and especially for pointing out
that I *don't* need to re-implement isdnd (that was a huge
waste of time !) :-]
input routines and take advantage of the new init/continue
interface in libradius. This allows a timely response on
other links in an MP setup while RADIUS requests are in
progress as well as the ability to handle other data from
the peer in parallel. It should also make the future addition
of PAM support trivial.
While I'm in there, validate pap & chap header IDs if
``idcheck'' is enabled (the default) for other FSM packet
types.
NOTE: This involved integrating the generation of chap
challenges and the validation of chap responses
(and commenting what's going on in those routines).
I currently have no way of testing ppps ability
to respond to M$Chap CHALLENGEs correctly, so if
someone could do the honours, it'd be much
appreciated (it *looks* ok!).
Sponsored by: Internet Business Solutions Ltd., Switzerland
(see the new ``set callback'' and ``set cbcp'' commands)
o Add a ``cbcp'' log level and mbuf type.
o Don't dump core when \T is given in ``set login'' or
``set hangup''.
o Allow ``*'' and blanks as placeholders in ppp.secret and
allow a fifth field for specifying auth/cbcp dialback
parameters.
o Remove a few extraneous #includes
o Define the default number of REQs (restart counter) in defs.h
rather than hardcoding ``5'' all over the place.
o Fix a few man page inconsistencies.
generate the data to transfer.
o Transfer uucp lock ownership for the transferred device.
o Don't assume we know the correct values of dev_is_modem and
mbits after the transfer.
is not possible to switch to or from dedicated or direct mode,
but all other combinations are ok (eg. -auto -> -ddial).
o Cope with the fact that commands with optional context may not
be able to obtain a link with command_ChooseLink() (if all links
have been deleted for example).
o Allow `clone'ing in non-multilink mode. We may for example want
to configure two links in unilink mode and dial them both, using
the one that comes up first. It's also possible to rename
``deflink'' by cloning it, deleting the original, then setting
the mode of the new link.
the bundle has the opportunity to go PHASE_DEAD and cleanup
the interface (if it's the last link).
o Regnerate our phys_type value when we transfer the link.
o Always clean up the interface when destroying our bundle in case
we're abending.
o Always clean up our interface when the last link is gone rather than
delaying things 'till exit time in the -direct case (the interface
is useless anyway). Do this *after* slamming down our NCPs (if
they're still around).
o Our MP server descriptor now clears the relevent device descriptor
from our descriptor [fd]sets when a datalink is on death-row (to
be transferred to another running ppp), thus avoiding the possibility
of passing a bum descriptor to select() and having ppp abend.
o Handle the MP socket descriptor functions from within the bundle
descriptor functions. Now we ensure that the MP socket descriptor
functions see the descriptor sets *after* they've been seen by our
datalinks.
o Add/fix a few more comments.
using the scatter/gather array to transfer the link
information. The whole link is now passed in one message.
This is far better than the two `/bin/cat' processes per additional
link :-) I remember years ago thinking that file descriptor
transferral would be a really amazing facility !
Suggested by: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
and: Eivind Eklund <eivind@yes.no>
log debug'' without filling our filesystem/screen with
junk that we don't really want to see.
o change PHYS_STDIN to PHYS_DIRECT - we can handle incoming
connections that aren't on STDIN_FILENO now.
o Allow return values from our FSM LayerUp functions. If
LayerUp() fails, the FSM does an immediate FsmDown() without
calling the fsm_parent's Layer{Up,Down} functions.
o Clear the close-on-exec flag of file descriptor 3 when executing
chat programs so that our documented ability to communicate with
/dev/tty via that descriptor works. Also document it as
descriptor 3, not 4 :-O
o Allow a ``rm'' command as an alias for ``remove''.
o Fix the bind()/connect()/accept() calls made by the MP server.
o Create bundle_SendDatalink() and bundle_ReceiveDatalink().
This allows `struct datalink's to flatten themselves, pass
through a pipe (read: the eye of a needle !) and come alive
at the other end. The donator then fork()s & exec()s pppmpipe,
``passing'' the connection to another ppp instance.
*** PPP NOW TALKS MULTILINK :-))) ***
Our link utilization is hideous, and lots of code needs
tidying still. It's also probably riddled with bugs !
It's been tested against itself only, and has hung once,
so confidence isn't high....
we've determined if we're going to join another ppp invocation.
o Make ``show link'' show all link details, and ``show links''
just give a list of links and their current status.
o Show our current label in ``show bundle''.
o Allow link cloning and removal as soon as our MRRU is set.
o Make ``show lcp'' require context as nothing will ever change
in our MP LCP (it's auto-configured as per rfc1990).
o Initialise our LQM owner in hdlc_Init().
o Store our endpoint discriminator and authentication name at both
the datalink and multilink level and compare them when we've
finished AUTHENTICATE phase and before entering NETWORK phase.
If they don't match, close the link again.
Display the information in the appropriate ``show'' command.
o Initialise datalink::phone and datalink::fsmp.object properly
when we're cloning the link.
o Show which link we're passing LQRs on in our diagnostics.
o Reject endpoint discriminator REQs at the logical multilink
level.
o Remove the rest of our CARRIER and LINK logging setup.
o Shuffle things that live at the datalink level into
``show link'' rather than ``show modem''.
o Make both ``show'' commands prettier and more consistent,
and display carrier status, link type and our name in
``show modem''.
o Show redial and reconnect information in ``show link''
and remove ``show redial'' and ``show reconnect''.
o Down the correct link in bundle_LinkLost().
o Remove stale -direct and -background links at the end
of our main loop, not when we know they're going. This
prevents unexpected pointer-invalidations...
o If we ``set server'' with the same values twice, notice
and don't moan about failure.
o Record dial script despite our link mode. The mode may
be changed later (next mod) :-) We never run scripts
in -direct and -dedicated modes.
o Make ``set server none'' functional again.
o Correct datalink state array so that we don't report an
``unknown'' state.
o Pass struct ipcp to IpcpCleanInterface, not struct fsm.
o Create TUN_PREFIX define rather than hard-coding in main.c
o prompt_TtyInit now handles a NULL prompt for -direct mode
rather than having to create one then destroy it uncleanly.
o Mention our mode in the "PPP Started" LogPHASE message.
o Bring all auto links up when we have something to send.
o Remove some redundant Physical_*() functions.
o Show which connection is running a command when logging
commands.
o Initialise throughput uptime correctly.
o Move Var*Version into command.c
o Remove struct pppVars (and there was much rejoicing) !
o Forward-decl some structs in .h files to avoid include
ordering requirements and remove a few more redundant
#includes.
o Our diagnostic socket has its password set in the `set socket'
line only (not in ppp.secret).
o Passwords are per server socket (*VarAuthKey are gone)
o Authority is per prompt (VarLocalAuth is gone).
o Local logging is per prompt.
o Add a `show who' command to see who's connected. No identd
routine - just a `where the connection came from' display.
o SIGUSR1 is disabled for now - we have no way of choosing a
password for the socket created :-(
Prompts are attached as a list of `struct descriptor's in
struct bundle, and serviced under the bundles descriptor
service routines. Ultimately, everything should be done
like this.
Cosmetic:
o alphabeticalise SRCS in Makefile.
o Add a few comments in command.h
TODO: Start checking that we don't overflow the descriptor sets
in select() now that we can have any number of descriptors.
o Remove bundle2lcp(), bundle2ccp() and bundle2link().
They're too resource-hungry and we have `owner pointers'
to do their job.
o Make our FSM understand LCPs that are always ST_OPENED
(with a minimum code that != 1).
o Send FSM code rejects for invalid codes.
o Make our bundle fsm_parent deal with multiple links.
o Make timer diagnostics pretty and allow access via ~t
in `term' mode (not just when logging debug) and
`show timers'. Only show timers every second in debug
mode, otherwise we get too many diagnostics to be useful
(we probably still do). Also, don't restrict ~m in term
mode to depend on debug logging.
o Rationalise our bundles' phases.
o Create struct mp (multilink protocol). This is both an
NCP and a type of struct link. It feeds off other NCPs
for output, passing fragmented packets into the queues
of available datalinks. It also gets PROTO_MP input,
reassembles the fragments into ppp frames, and passes
them back to the HDLC layer that the fragments were passed
from.
** It's not yet possible to enter multilink mode :-( **
o Add `set weight' (requires context) for deciding on a links
weighting in multilink mode. Weighting is simplistic (and
probably badly implemented) for now.
o Remove the function pointers in struct link. They ended up
only applying to physical links.
o Configure our tun device with an MTU equal to the MRU from
struct mp's LCP and a speed equal to the sum of our link
speeds.
o `show {lcp,ccp,proto}' and `set deflate' now have optional
context and use ChooseLink() to decide on which `struct link'
to use. This allows behaviour as before when in non-multilink
mode, and allows access to the MP logical link in multilink
mode.
o Ignore reconnect and redial values when in -direct mode and
when cleaning up. Always redial when in -ddial or -dedicated
mode (unless cleaning up).
o Tell our links to `staydown' when we close them due to a signal.
o Remove remaining `#ifdef SIGALRM's (ppp doesn't function without
alarms).
o Don't bother strdup()ing our physical link name.
o Various other cosmetic changes.
Struct bundle will have its own struct ccp in the future
too.
o The ``set stopped'' command now requires context and doesn't
work on the IPCP FSM.
o Check if it's time to break out of our top level loop before
doing a select - otherwise, we'll select forever :-(
o Remove `struct link'::ccp (a temporary hack). It turns out
that IpStartOutput() calls link_Output() and link_Output()
incorrectly calls StartOutput() (really modem_StartOutput)
requiring the ccp knowledge so that it can call
IpStartOutput()... The end result is that the whole IP
output queue gets dumped into the modem output queue
and a pile of physical writes are done prematurely. This
makes the (original) code in main() actually work in that
it would not bother selecting() on the tun descriptor when
our modem queue length was 20 or greater. Instead, we now
make that decision based on the overall queue length.
This will need improvement later.
is available, but LCP hasn't yet been started. We get to this
state in ``term'' mode.
Remove PacketMode(). LCP startup and shutdown is now controlled
by the datalink.
Add ``show links'' command.
Make ``close'' capable of running with and without a context.
Make ``down'' require a context.
Make ``set parity'' and ``set rtscts'' use the correct context.
datalink_Up() can now be told to skip the dial/login/hangup
scripts and can be told whether to enter packet mode when
entering the DATALINK_OPENED state.
This is a type of physical link that can chat and talk
LCP & CCP. A bundle contains a list of these (only one
in the list for the moment).
The datalink is a type of descriptor, and dials, enters
LCP (& does CCP), kicks the bundle when its FSMs do
something interesting and does the hangup chat script
on the way down. It also handles redials and reconnects.
There are lots of loose ends, and probably lots of bugs,
but the data structures are getting there !
