From lwIP CHANGELOG
(STABLE-2.1.2):
++ Bugfixes:
2018-11-21: Jens Nielsen
* netbiosns.c: fix expecting too large packet (bug #55069)
2018-11-19: Dirk Ziegelmeier
* smtp.c: fix compiling with strict C compatibility because of strnlen (bug #55034)
2018-11-12: Simon Goldschmidt
* tcp.c: fix overflow check in tcp_recved triggering invalid assertion (bug #55015)
2018-11-12: Simon Goldschmidt
* tcp.c: fix a bug in sending RST segments (sent from port 0)
(STABLE-2.1.1):
++ Bugfixes:
2018-11-01: Joan Lledó
* sockets.c: fix bad assertion in lwip_poll_dec_sockets_used() (bug #54933)
2018-11-01: Dirk Ziegelmeier
* ip4.c: don't send 127.* to default netif (bug #54670)
2018-10-23: David Girault
* altcp_tls_mbedtls.c: fix use-after free (bug #54774)
2018-10-23: Ognjen Bjelica, Dirk Ziegelmeier
* snmp_scalar.c: Avoid NULL pointer dereference (bug #54886)
2018-10-23: Simon Goldschmidt
* Fix missing standard includes in multiple files
2018-10-17: Ivan Warren
* def.h: fix casting htonX and ntohX to u16_t (bug #54850)
2018-10-12: Simon Goldschmidt
* Revert "tcp_abandon: no need to buffer pcb->local_port" (fix that source port was 0 for RST
called when aborting a connection)
2018-10-11: Jonas Rabenstein
* tcp.c: tcp_recved: check for overflow and warn about too big values (patch #9699)
2018-10-06: Joan Lledó
* sockets.c: alloc_socket(): Check for LWIP_SOCKET_POLL when setting select-
related variables (patch #9696)
2018-10-04: Spencer
* tcp.c: Update prev pointer when skipping entries in tcp_slowtmr (patch #9694)
2018-09-27: Martine Lenders
* lowpan6.c: Fix IEEE 802.15.4 address setting (bug #54749)
