This commit address two issues with sockaddr struct implementations for
IPv6:
1) struct sockaddr_in6 should have 32-bit unsigned field sin6_scope_id
as specified in Section 3.4 of RFC 3493 (Basic Socket Interface
Extensions for IPv6)
2) struct sockaddr is not extended in IPv6 to contain space for
struct sockaddr_in6. Applications should be using struct
sockaddr_storage when needing generic storage. This removes the
extra bytes added when LWIP_IPV6 is defined
the netif_add_ip6_address function was declared err_t in
src/include/lwip/netif.h, but defined as s8_t (the default value of
err_t) in its implementation in src/core/netif.c.
this causes "conflicting types for 'netif_add_ip6_address'" errors if
err_t is defined differently in cc.h (as for example recommended in
[1]).
as it only returns error constants, it is changed to use err_t
throughout.
[1] http://lwip.wikia.com/wiki/Porting_For_Bare_Metal
Writes to offsets pointing to the start of a pbuf in the chain
did nothing and just returned ERR_OK.
Added unit tests to verify the fix, and also
that pbuf_get_at()/pbuf_put_at() handles this case.
When LWIP_HAVE_LOOPIF is enabled, a separate loopback interface is added
as a netif. A netif need to have its link state set to up to be able to be
selected as a route in ip4_route or ip6_route.
The regression appears to be when bug #43904 (ip_route() and ip6_route()
must detect linkup status) was fixed.
Furthermore, there is no point of having the loopif down by default.
This commit fixes a bug in netbuf_destport() where LWIP_NETBUF_RECVINFO is
enabled, but not LWIP_CHECKSUM_ON_COPY is enabled
The flags field is only available when LWIP_CHECKSUM_ON_COPY is enabled. In
this mode, the toport_chksum is dual functioning as storage for port and
checksum
When a client sends an ICMP echo request with ID 0, sequence 0 and
either no data or any amount of 0x00 bytes as data, the checksum in the
reply is wrong (off-by-one).
Expected checksum is 0xffff in that case, observed is 0x0000.
We used a static 4 instead of MEM_ALIGNMENT earlier, however it broke
things for MEM_ALIGNMENT 1 or 2, fixed using a LWIP_MIN(MEM_ALIGNMENT,
4) statement.
