1. Move htonl() etc. from <arpa/inet.h> to <netinet/in.h> (which
<arpa/inet.h> includes).
The htonl(), htons(), ntohl(), and ntohs() functions shall be
available as described in <arpa/inet.h>. Inclusion of the
<netinet/in.h> header may also make visible all symbols from
<arpa/inet.h>.
- POSIX
2. Define IN6_IS_ADDR_LOOPBACK() and IN6_IS_ADDR_V4MAPPED()
An IP socket can now join a multicast group by using the
IP_ADD_MEMBERSHIP sockopt, which will cause it to start receiving
packets sent to the multicast address, even though this address does
not belong to this host.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Mostly due to the fact that clang-format allows aligned comments via
AlignTrailingComments.
We could also use raw string literals in inline asm, which clang-format
deals with properly (and would be nicer in a lot of places).
