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2018-09-04Implement socket option recvtos and friendsRaimo Niskanen
Implement socket options recvtclass, recvtos, recvttl and pktoptions. Document the implemented socket options, new types and message formats. The options recvtclass, recvtos and recvttl are boolean options that when activated (true) for a socket will cause ancillary data to be received through recvmsg(). That is for packet oriented sockets (UDP and SCTP). The required options for this feature were recvtclass and recvtos, and recvttl was only added to test that the ancillary data parsing handled multiple data items in one message correctly. These options does not work on Windows since ancillary data is not handled by the Winsock2 API. For stream sockets (TCP) there is no clear connection between a received packet and what is returned when reading data from the socket, so recvmsg() is not useful. It is possible to get the same ancillary data through a getsockopt() call with the IPv6 socket option IPV6_PKTOPTIONS, on Linux named IPV6_2292PKTOPTIONS after the now obsoleted RFC where it originated. (unfortunately RFC 3542 that obsoletes it explicitly undefines this way to get packet ancillary data from a stream socket) Linux also has got a way to get packet ancillary data for IPv4 TCP sockets through a getsockopt() call with IP_PKTOPTIONS, which appears to be Linux specific. This implementation uses a flag field in the inet_drv.c socket internal data that records if any setsockopt() call with recvtclass, recvtos or recvttl (IPV6_RECVTCLASS, IP_RECVTOS or IP_RECVTTL) has been activated. If so recvmsg() is used instead of recvfrom(). Ancillary data is delivered to the application by a new return tuple format from gen_udp:recv/2,3 containing a list of ancillary data tuples [{tclass,TCLASS} | {tos,TOS} | {ttl,TTL}], as returned by recvmsg(). For a socket in active mode a new message format, containing the ancillary data list, delivers the data in the same way. For gen_sctp the ancillary data is delivered in the same way, except that the gen_sctp return tuple format already contained an ancillary data list so there are just more possible elements when using these socket options. Note that the active mode message format has got an extra tuple level for the ancillary data compared to what is now implemented gen_udp. The gen_sctp active mode format was considered to be the odd one - now all tuples containing ancillary data are flat, except for gen_sctp active mode. Note that testing has not shown that Linux SCTP sockets deliver any ancillary data for these socket options, so it is probably not implemented yet. Remains to be seen what FreeBSD does... For gen_tcp inet:getopts([pktoptions]) will deliver the latest received ancillary data for any activated socket option recvtclass, recvtos or recvttl, on platforms where IP_PKTOPTIONS is defined for an IPv4 socket, or where IPV6_PKTOPTIONS or IPV6_2292PKTOPTIONS is defined for an IPv6 socket. It will be delivered as a list of ancillary data items in the same way as for gen_udp (and gen_sctp). On some platforms, e.g the BSD:s, when you activate IP_RECVTOS you get ancillary data tagged IP_RECVTOS with the TOS value, but on Linux you get ancillary data tagged IP_TOS with the TOS value. Linux follows the style of RFC 2292, and the BSD:s use an older notion. For RFC 2292 that defines the IP_PKTOPTIONS socket option it is more logical to tag the items with the tag that is the item's, than with the tag that defines that you want the item. Therefore this implementation translates all BSD style ancillary data tags to the corresponding Linux style data tags, so the application will only see the tags 'tclass', 'tos' and 'ttl' on all platforms.
2016-06-01Rewrite inet* for address family 'local'Raimo Niskanen
2016-01-12Assign externally open fd to gen_tcp (UDS support)Serge Aleynikov
When a AF_LOCAL file descriptor is created externally (e.g. Unix Domain Socket) and passed to `gen_tcp:listen(0, [{fd, FD}])`, the implementation incorrectly assigned the address family to be equal to `inet`, which in the inet_drv driver translated to AF_INET instead of AF_LOCAL (or AF_UNIX), and an `einval` error code was returned. This patch fixes this problem such that the file descriptors of the `local` address family are supported in the inet:fdopen/5, gen_tcp:connect/3, gen_tcp:listen/2, gen_udp:open/2 calls
2015-10-12Merge branch 'stolen/unified_dist' into maintZandra
OTP-13040 * stolen/unified_dist: kernel: inet6_tcp_dist: reuse inet_tcp_dist code Conflicts: lib/kernel/src/inet_tcp_dist.erl
2015-06-18Change license text to APLv2Bruce Yinhe
2015-05-02kernel: inet6_tcp_dist: reuse inet_tcp_dist codeDanil Zagoskin
inet6_tcp_dist module is an old copy of inet_tcp_dist with changed address family. New features (such as listening port range, interface and generic options) are implemented in inet_tcp_dist only, inet6_tcp_dist looks abandoned (it does not even have tests). This patch makes inet_tcp_dist internals work with abstract driver, and inet6_tcp_dist becomes just a thin wrapper for it.
2011-11-17erts,kernel: Add type stream sockets to SCTPRaimo Niskanen
2009-11-20The R13B03 release.OTP_R13B03Erlang/OTP