PPP: remove PPP_PHASE_MASTER conditions if multilink mode is disabled

PPP_PHASE_MASTER state is only used if multilink mode is enabled. Since
we don't support multilink mode checking for this state only add some
code for no value added at all.

Build-out PPP_PHASE_MASTER state check if multilink mode is disabled.

doxygen updates - include IPv6 in documentation. Exclude include/netif/ppp/polarssl.
Convert TODO -> @todo

PPP: Use LWIP_ARRAYSIZE at appropriate places

Use LWIP_ARRAYSIZE to simplify the code.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Sylvain Rochet <gradator@gradator.net>
[Sylvain Rochet <gradator@gradator.net>: added missing casts]
Signed-off-by: Sylvain Rochet <gradator@gradator.net>

Work on task #13907 PPP cleanups: Move PPP options from opt.h to dedicated ppp_opts.h file

PPP: Fix shadowing of global declaration

Older compilers (GCC 4.6) don't like variables with the same name as
global functions:

lwip/src/netif/ppp/lcp.c: In function 'lcp_received_echo_reply':
lwip/src/netif/ppp/lcp.c:2685:11: error: declaration of 'magic' shadows a global declaration [-Werror=shadow]
lwip/src/include/netif/ppp/magic.h:101:7: error: shadowed declaration is here [-Werror=shadow]

magic.h contains a function named magic(), so rename the variable.

PPP: more const and mixed u_char/char types fixes

PPP: fix constness in PPP related files when PRINTPKT_SUPPORT is enabled

PPP, re-enabled MRU defines in opt.h

PPP, place print packet debug codenames in ROM

PPP, CORE, SERVER, set auth configuration before auth

Set LCP wanted options accordingly to the user auth configuration
if peer is required to authenticate itself.

PPP, CORE, moved auth configuration from auth_reset() to lcp_resetci()

Prepare for PPP_SERVER support, we need to move auth configuration before
lcp_allowoptions is copied into lcp_gotoptions. Restore unused
auth_reset() function using pppd original source code.

PPP, CORE, don't use ppp_ioctl() from PPP core, assign pcb->err_code instead

Removed useless calls to ppp_ioctl(pcb, PPPCTLS_ERRCODE, …), we now assign
pcb->err_code directly instead. ppp_ioctl() is not linked anymore if user
application don't use it.

PPP, CORE, compile out auth support if none of auth protocols are enabled

Added macro PPP_AUTH_SUPPORT, if none of auth protocols are enabled
(PAP, CHAP, EAP) we reduce PPP memory usage by compiling out all
struct fields and source code used for authentication.

PPP, CORE, Removed (*datainput) from struct protent if not used

Data input is only used by CCP and ECP, which are not supported at this time,
remove this entry from struct protent to save some flash.

PPP, CORE, Removed useless enabled_flag from struct protent

Our struct protent are const everywhere to save RAM, enable/disable
flag on a const struct is useless, saving some flash, removed.

PPP, PPPoS, removed xmit_accm, almost duplicate of out_accm

xmit_accm was meant to be a user configurable asyncmap, it was actually
broken since the introduction of ppp_new by the way we now reset the PPP
initial state, looks like no one until now is needing it anymore. If
necessary we will reintroduce this feature later properly instead of a
dirty and ugly hack into the PPP code.

PPP, fixed some compiler warnings

Using -Wall -pedantic -Wparentheses -Wsequence-point
-Wswitch-default -Wextra -Wundef -Wshadow -Wpointer-arith
-Wbad-function-cast -Wc++-compat -Wwrite-strings -Wold-style-definition
-Wmissing-prototypes -Wredundant-decls -Wnested-externs -Wno-address

fixed bug #43235, cleared compiler warnings when using gcc with -Wextra option

PPP, added PPP notify phase support

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 */
}
}

PPP, added PPP_USE_PBUF_RAM compile time option

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.

PPP, fixed LCP delayed up feature

LCP is stealing a bit from fsm->flags struct member for LCP delayed up feature.
Bit stealed used to be the 9th bit (0x100) but fsm->flags was reduced to u8_t to save memory,
we are now stealing the 8th bit (0x80).

PPP, "try" variable used in LCP might conflict with some buggy C++ compiler

PPP, fixed one more IAR warnings

PPP, adding const pragma to FSM callbacks, saving about 350 bytes in .data segment

PPP, adding const pragma to struct protent, saving about 200 bytes in .data segment

PPP, IAR EWARM won't compile ppp-new due to keyword clash

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_".

PPP, using PBUF_POOL instead of PBUF_RAM pbufs for PPP negociation packets

PPP stack does not handle chained pbuf, but PPP negociation packets
are at most ~40 bytes long, so we are only checking if the payload
can fit into the allocated pbuf (p->tot_len == p->len).

PPP, renamed all functions using common names in utils.c that can conflict with lwIP user code during link operation

Moved PPP headers into include/netif/ppp/, fixing bug #37040.

improved persist mode, we now clear everything we can in the PPP control block structure, ensuring we start a new session from a clean state

some buggy compiler get confused with duplicated labels used in enum tcp_state and fsm.h, prepending PPP's ones

fixed LCP Echo Request/Reply feature

replaced u_int{8,16,32}_t to lwIP u{8,16,32}_t types

added padding to compiler generated bitfield, this is seen as best practice,
maybe it helps buggy compilers

fixed some endianess issues with PPPoS

fixed PPPoS suppport compilation

improved lcp_options structure size

LCP and IPCP variable size improved

removed pcb->chap_mdtype_all

replaced exit code (pcb->status) with ppp_ioctl()

pcb->nak_buffer replaced with a pbuf

moved back temporarily moved structure definitions from various headers to ppp.h during unit to ppp_pcb transition

fixed PPPoS xmit_accm ppp_pcb variable access

LCP global variables moved to ppp_pcb as well as input/output buffers

FSM global variables moved to ppp_pcb

removed fsm->unit

protent prototype switched from unit to ppp_pcb

IPCP and LCP structures moved to ppp_pcb

global variables removed from chap support

auth.c functions now use ppp_pcb* as first argument

started the unit to ppp_pcb replacement

added missing EAP_SUPPORT macro

renamed ppp_control to ppp_pcb, replaced unit number to ppp_pcb in all ppp.h declared functions

moved ppp_settings to ppp_control, improved PPP API to really allow multiple PPP sessions

moved exit status global variable to ppp_control

moved listen_time global variable to ppp_settings

phase global variable moved to ppp_control structure

removed multilink option when multilink support is not compiled

we should reduce nak_buffer[] size

re-enabled LCP echo interval / echo fail

cleared IDE warnings

cleaned depreacted __P() and __V() macros, removed the legacy varargs.h header

ppp_impl.h is back!

re-added PPPoS code from the previous port, it builds, maybe it works

don't build any PPP file if PPP support is disabled

LQR (Link Quality Report) support is now optional

removed all system headers except the strict minimum

make it build with avr32-gcc

Disabled Unix-centric non necessary include files

Changed some include paths

Removed all printf() I put there and there for debugging.

It builds with the avr32 gcc toolchain, meaning we removed
all the pppd code requiring a unix base.

fixed most PPP compilation warnings with -pedantic

fixed all PPP compilation warnings with -Wall

removed pppd.h and ppp.c, renamed pppmy.c to ppp.c and pppmy.h to ppp.h

pppd.h disabled, renamed MAX() to LWIP_MAX()

PPP statistics optional (non working) compile time option added

moved new_phase() to our own implementation, re-enabled new_phase() support

PPP notifier support is now a compile time option

However, as of now, the notify() function is empty, so it requires
some work if someone want to use it.

The notify feature allows someone to be able to follow the
state of the PPP stack (auth ok, ipcp up, initialise, ...), this
is like the callback feature set by pppOverEthernetOpen() and others,
but with more details.

PPP interval timeout support disabled (using lwIP timeout support), protocol_name() moved to our PPP impl and disabled by default

removed more protent fields only used by print packets functions

print packet functions are now optional

demand support is now a compile-time option

Obviously, it requires some wiring to know if there is new activity
on a not-yet established PPP interface with the default route
already set.

I don't think any lwIP user will ever need that, all should know
when to bring the link up and down.

PAP support is now an optional compile-time feature

CHAP support is now an optional compile-time feature

MSCHAP is now an optional compile-time feature

replaced BCOPY to lwip-MEMCPY

more and more ppp options removal

disabled almost all PPP options strings and support as well as useless file-based auth code

EAP support is now optional

replaced MIN to LWIP_MIN

using UNTIMEOUT macro instead of timeout()

pppd: Terminate correctly if lcp_lowerup delayed calling fsm_lowerup

added LCP adaptive echo from Debian patches, I like the idea

Early development stage of an attempt to port PPPd 2.4.5 to lwIP.

PPPoE works, PPPoS code is not ported at all.

I am using the RP-PPPoE server to do my tests using the following
configuration:

$ cat /etc/ppp/pppoe-server-options
debug
login
lcp-echo-interval 10
lcp-echo-failure 10
ms-dns 192.168.4.130
ms-dns 192.168.4.231
netmask 255.255.255.0
defaultroute
noipdefault
usepeerdns

$ cat /etc/ppp/allip
192.168.4.1-200

$ pppoe-server -C isp -L 192.168.4.254 -p /etc/ppp/allip -I tap0

Plus the usual auth-lines in /etc/ppp/pap-secrets and
/etc/ppp/chap-secrets .

And the unix port minimal "echo" project slightly modified to use
the "tcpip" API, so with threads, which I am going to commit with
NO_SYS as a -Dmacro.

It still use some of the linux'ism, such as syslog() and crypt(),

I do not want to drop the syslog() supports at the moment, this is
pretty useful to debug, and we may just convert the way the syslog() is
done to provide a trace feature to our PPP users, as a compile-time
option.

splitted ppp.h to an internal and external header file to get a clear separation of which functions an application or port may use (task #11281)

Fixed bug #29855: PPP: Backport a bugfix in LcpSendEchoRequest from pppd

PPP: use LWIP_DEBUGF() instead of ppp_trace()

Added debug output and missing casts

Replaced tabs with spaces

bug #26523: Compiler Warnings

reorganised PPP sourcecode to 2.3.11 including some bugfix backports from 2.4.x.

Reorganised PPP source code from ucip structure to pppd structure to easily compare our code against the pppd code (around v2.3.1)

Minor changes in PPP (coding style, tabs, idents...)

Minor changes: fix some problems with PPPoE include path, add small comments in slip.c (unusual octal values?)

First fix for bug #21664 "PPP code is broken".

Added PPPoE support and various PPP improvements.

Ongoing fix to patch #5822: converted more statements like (void)arg; into LWIP_UNUSED_ARG(arg);

Some build fixes for OpenBSD.

Dependencies on C library memset() etc., so include <string.h>.

sio and PPP updates from Marc

Cleanups in PPP: C++ comments removed, make it compile for unixsim too. Does not work yet only compiles

add PPP stack from Marc. Work in progress