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>

PPP: use mbed TLS sanitize functions if available

mbed TLS offers sanitize functions to zero-ise memory containing
cryptographic keys, use them if built with external mbed TLS library.

PPP: add a function map for hashes and ciphers to prepare for mbed TLS support

Unfortunately, all functions were renamed when PolarSSL was renamed to
mbed TLS, breaking the API. In order to continue supporting our embedded
PolarSSL copy while allowing our users to use mbed TLS, we need a function
map to deal with the API break.

This commit add a function map for all hashes and ciphers we are currently
using.

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

PPP: more const and mixed u_char/char types fixes

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

PPP, magic, using magic_random_bytes() for CHAP/MSCHAP/EAP instead of for-loop byte where possible

PPP, cleanup unused/redefined/useless limits in ppp_impl.h

PPP, place print packet debug codenames in ROM

PPP, EAP: using MAXNAMELEN define instead of hardcoded 256 size for rhostname

PPP, EAP: removed malloc() and free()

Replaced pcb->eap.es_{client,server}.ea_peer pointer to a char table,
replaced strdup() with MEMCPY, etc.

PPP, replaced drand48() with magic_pow()

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, added const modifier on auth strings

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_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, moved EAP configuration to ppp_settings struct

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

PPP, changed all the code enclosed between PPP_SERVER #if macro to our PPP PCB structure, making it easier to support PPP server in the future

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.

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

merged ppp_write and ppp_write_pbuf

don't duplicate user and password anymore, anyway, the PPP user will have them already allocated as static strings or from configuration flash/file

ppp_settings.remote_name is now a compile time option

do not allocated pbuf of more than pcb->peer_mru instead of PPP_MRU, to save some memory

pcb->outpacket_buf replaced by pbuf everywhere it was used

prevent conflict with existing (md4|md5|sha1|des) object file if polarssl is already used elsewhere in the project

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

protent prototype switched from unit to ppp_pcb

EAP is now using ppp_pcb as well

moved auth.c global variables to ppp_pcb

auth.c functions now use ppp_pcb* as first argument

started the unit to ppp_pcb replacement

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 remote_name and explicit_remote global variable to ppp_settings

PPP server support is now optional (disabled by default, not working until PPP have a "listen" support)

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

ppp_impl.h is back!

clarified a bit more ppp.[ch]

demystified a bit the PPP impl, renamed output() to ppp_output() to prevent conflict

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

added pppmy.h in all .c files to easily find conflicts

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.

removed pathnames.h and pidfile support

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

Revert "Revert "Added PolarSSL DES library, which is necessary for MSCHAP.""

This reverts commit a820f32ec936a1a699ef76adb3fa8ea0915fc152.

Revert "Revert "Replaced md4/md5/sha1 implementations to PolarSSL ones""

This reverts commit ca2fd867b8e6b92ab4338c504e5b9567ab76e414.

EAP support is now optional

removed useless system header from EAP

Revert "Replaced md4/md5/sha1 implementations to PolarSSL ones"

This reverts commit aa2656cb9e8f6cdd7921fc36d5e00060065058a4.

Licence issue, we cannot include GPLed source code.

Revert "Added PolarSSL DES library, which is necessary for MSCHAP."

This reverts commit de70b710af43942130690e9225b32b02cea279aa.

Licence issue, we cannot include GPLed source code.

Added PolarSSL DES library, which is necessary for MSCHAP.

Added a README about our PolarSSL included files, clarifying what we did.

Removed crypt(), -lcrypt ( setkey() / encrypt() ) dependencies.

Replaced md4/md5/sha1 implementations to PolarSSL ones

Using cleaned PolarSSL md4/md5/sha1 implementations, without changing the API,
so that lwIP users already doing SSL or using PolarSSL don't need to compile
md4/md5/sha1 twice.

Added to that, we need a DES library for MSCHAP, and PolarSSL provided
a DES support.

And finally, PolarSSL is outstanding :-)

don't compile wkmodulus[] if SRP is not used

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.