The only benefit of ppp_new() call was about having a persistent netif
interface. netif was moved out of PPP pcb so we don't need ppp_new()
anymore, first step in simplifying the weird new/open/free/delete PPP
API.
Users might want to share a netif control block between an Ethernet
interface and a PPPoS interface (I want actually) in case PPP is just
used as redundancy if Ethernet is down (eg. PPPoS GPRS fail over).
Moved netif out of PPP control block in a similar way it is currently
done for Ethernet interfaces. Furthermore, this is a first step on
removing the "new/create/free/delete" API which is awful but currently
necessary to handle fail over from PPPoX to another PPPoX (eg. from PPoE
on xDSL to PPPoS on GPRS fail over) without free()ing the netif which
might be used on udp_sendto() or L2TP VPN links.
The current code is buggy regarding handling of link state when using
both IPCP and IPv6CP: if IPv6CP has been set up and if during IPCP
negociation, ipcp_up() fails, it will incorrectly take the interface
down. The simple solution here is to change the platform code to do the
same as on Solaris: separate IPv6CP up/down state handling with sif6up()
and sif6down(), so that we really know when the interface is allowed to
go down.
(Based from pppd commit b04d2dc6df5c6b5650fea44250d58757ee3dac4a)
Based from pppd 2.4.5, released 2009-11-17, with huge changes to match
code size and memory requirements for embedded devices, including:
- Gluing together the previous low-level PPP code in lwIP to pppd 2.4.5, which
is more or less what pppd sys-* files are, so that we get something working
using the unix port.
- Merged some patchs from lwIP Git repository which add interesting features
or fix bugs.
- Merged some patchs from Debian pppd package which add interesting features
or fix bugs.
- Ported PPP timeout handling to the lwIP timers system
- Disabled all the PPP code using filesystem access, replaced in necessary cases
to configuration variables.
- Disabled all the PPP code forking processes.
- Removed IPX support, lwIP does not support IPX.
- Ported and improved random module from the previous PPP port.
- Removed samba TDB (file-driven database) usage, because it needs a filesystem.
- MS-CHAP required a DES implementation, we added the latest PolarSSL DES
implementation which is under a BSD-ish license.
- Also switched to PolarSSL MD4,MD5,SHA1 implementations, which are meant to be
used in embedded devices with reduced memory footprint.
- Removed PPP configuration file parsing support.
- Added macro definition EAP_SUPPORT to make EAP support optional.
- Added macro definition CHAP_SUPPORT to make CHAP support optional.
- Added macro definition MSCHAP_SUPPORT to make MSCHAP support optional.
- Added macro definition PAP_SUPPORT to make PAP support optional.
- Cleared all Linux syscall calls.
- Disabled demand support using a macro, so that it can be ported later.
- Disabled ECP support using a macro, so that it can be ported later.
- Disabled CCP support using a macro, so that it can be ported later.
- Disabled CBCP support using a macro, so that it can be ported later.
- Disabled LQR support using a macro, so that it can be ported later.
- Print packet debug feature optional, through PRINTPKT_SUPPORT
- Removed POSIX signal usage.
- Fully ported PPPoS code from the previous port.
- Fully ported PPPoE code from the previous port.
- Fully ported VJ compression protocol code from the previous port.
- Removed all malloc()/free() use from PPP, replaced by stack usage or PBUF.
- Disabled PPP server support using a macro, so that it can be ported later.
- Switched all PPP debug to lwIP debug system.
- Created PPP Control Block (PPP PCB), removed PPP unit integer everywhere,
removed all global variables everywhere, did everything necessary for
the PPP stack to support more than one PPP session (pppd only support
one session per process).
- Removed the statically allocated output buffer, now using PBUF.
- Improved structure size of all PPP modules, deep analyze of code to reduce
variables size to the bare minimum. Switched all boolean type (char type in
most architecture) to compiler generated bitfields.
- Added PPP IPv6 support, glued lwIP IPv6 support to PPP.
- Now using a persistent netif interface which can then be used in lwIP
functions requiring a netif.
- Now initializing PPP in lwip_init() function.
- Reworked completely the PPP state machine, so that we don't end up in
anymore in inconsistent state, especially with PPPoE.
- Improved the way we handle PPP reconnection after disconnect, cleaning
everything required so that we start the PPP connection again from a
clean state.
- Added PPP holdoff support, allow the lwIP user to wait a little bit before
reconnecting, prevents connection flood, especially when using PPPoL2TP.
- Added PPPoL2TP LAC support (a.k.a. UDP tunnels), adding a VPN client
feature to lwIP, L2TP being a widely used tunnel protocol.
- Switched all used PPP types to lwIP types (u8t, u16t, u32t, ...)
- Added PPP API "sequential" thread-safe API, based from NETIFAPI.
PPP notify phase support, using compile-time PPP_NOTIFY_PHASE macro.
This can be used for example to set a LED pattern depending on the
current phase of the PPP session.
Callback example:
static void ppp_notify_phase_cb(ppp_pcb *pcb, u8_t phase, void *ctx) {
switch(phase) {
case PPP_PHASE_DEAD: /* Kept off */
case PPP_PHASE_MASTER:
/* LED Off */
break;
case PPP_PHASE_INITIALIZE: /* Session opened */
/* LED FastBlink */
break;
case PPP_PHASE_RUNNING: /* Session running */
/* LED On */
break;
default:
/* LED SlowBlink */
}
}
pbuf_type PPP is using for LCP, PAP, CHAP, EAP, IPCP and IP6CP packets.
Memory allocated must be single buffered for PPP to works, it requires pbuf
that are not going to be chained when allocated. This requires setting
PBUF_POOL_BUFSIZE to at least 512 bytes, which is quite huge for small systems.
Setting PPP_USE_PBUF_RAM to 1 makes PPP use memory from heap where continuous
buffers are required, allowing you to use a smaller PBUF_POOL_BUFSIZE.
I consider to remove the PPP_INPROC_OWNTHREAD crap in ppp-new,
as said in bugs #37278 and #37353.
1. It requires the ppp_input_thread() function to be modified to match
user system, like some did by adding the vTaskDelete(NULL); FreeRTOS
call at the end of the function, for example.
This is a tiny-tiny fonction that should be, in my opinion, on the user
port, like the Ethernet input thread we see in many Ethernet port.
2. It is actually not that thread safe.
2.1. pcb->phase IS modified by the lwIP core thread so it should at
least be set to volatile, otherwise the pcb->phase copy may live
indefinitely in CPU register. It works because of the sio_read()
function call which without doubt flush pcb->phase copy from CPU
register. I dont want to set ppp_pcb struct to volatile for obvious
performance reasons.
2.2. This function assume PCB still exists whatever is happening, which
is not the case after you called ppp_delete() function outside of this
thread. If sio_read() is blocking waiting data and pcb destroyed, it is
going to read a deallocated pcb which luckily should still have
pcb->phase set to 0 (=PHASE_DEAD) due to preallocated "control block"
structures of lwIP. Even with sio_read_abort(), there might be timings
issue due to a lack of a synchronization mechanism.
3. I dislike the sys_msleep(1), it means that systems should have at
least a 11 chr buffer at 115200/10 byte/s, and bigger with higher serial
speed, for example with 3G/HSDPA modems accessed through SPI, at 20
Mbits/s this is a ~2000 bytes buffer required to keep incoming data
during this sleep, I don't see why we require systems to do so,
sio_read() should obviously be a blocking call. I cannot easily
remove this sleep because some systems might have wrongfully used this
call as a CPU idle feature with a non blocking sio_read() call.
Free the control block, clean everything except the PPP PCB itself
and the netif, it allows you to change the underlying PPP protocol
(eg. from PPPoE to PPPoS to switch from DSL to GPRS) without losing
your PPP and netif handlers.
Created new ppp_over_X_create() functions which only prepare the PPP session without starting it
Removed ppp_reopen() and all of its sub ppp_over_X_reopen()
Removed PPPoL2TP reconnect() function, merged to connect()
Added ppp_open() able to start or restart any session
The word "class" is reserved in IAR's EWARM compiler since it looks like c++.
This causes a failure to compile in the lcp code.
Arguably it is a bug in the compiler, but it is easy to work around with a
name change in the lcp.[ch] code. I fixed it by changing "class" to "class_".
