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
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).
these are the compiler warnings I get with the head of ppp-new. All
of them are trivial, [...] (I'm using IAR EWARM 6.4).
ppp.c
Warning[Pe550]: variable "c" was set but never used
lwip\src\netif\ppp\ppp.c 1012
Warning[Pe111]: statement is unreachable
lwip\src\netif\ppp\ppp.c 1132
Warning[Pe111]: statement is unreachable
lwip\src\netif\ppp\ppp.c 1377
Warning[Pe111]: statement is unreachable
lwip\src\netif\ppp\ppp.c 1412
utils.c
Warning[Pe186]: pointless comparison of unsigned integer with zero
lwip\src\netif\ppp\utils.c 210
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 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).
The lwIP PPP support is based from pppd 2.4.5 (http://ppp.samba.org) with
huge changes to match code size and memory requirements for embedded devices.
Anyway, pppd has a mature codebase for years and the average commit count
is getting low on their Git repositories, meaning that we can follow what
is happening on their side and merge what is relevant for lwIP.
So, here is the pppd follow up, so that we don't get away too far from pppd.
The only way PPPoE or PPPoL2TP disconnect it through ppp_link_terminated(),
therefore PPP is always already down, so we don't need to ask PPP to hup or stop.
This is now the user choice to re-establish the session in the link status callback
by either calling the ppp_reopen() to re-establish or ppp_delete() to free the PPP
control block. Without user intervention, the PPP control block now stay in the dead
phase, allowing the user to re-establish or delete the control block later.
