kernel/linux.git/include/linux/in6.h, branch v6.19.11

ipv6: Add sockaddr_inet unified address structure

2025-07-25T22:29:58+00:00

There are cases in networking (e.g. wireguard, sctp) where a union is used to provide coverage for either IPv4 or IPv6 network addresses, and they include an embedded "struct sockaddr" as well (for "sa_family" and raw "sa_data" access). The current struct sockaddr contains a flexible array, which means these unions should not be further embedded in other structs because they do not technically have a fixed size (and are generating warnings for the coming -Wflexible-array-not-at-end flag addition). But the future changes to make struct sockaddr a fixed size (i.e. with a 14 byte sa_data member) make the "sa_data" uses with an IPv6 address a potential place for the compiler to get upset about object size mismatches. Therefore, we need a sockaddr that cleanly provides both an sa_family member and an appropriately fixed-sized sa_data member that does not bloat member usage via the potential alternative of sockaddr_storage to cover both IPv4 and IPv6, to avoid unseemly churn in the affected code bases. Introduce sockaddr_inet as a unified structure for holding both IPv4 and IPv6 addresses (i.e. large enough to accommodate sockaddr_in6). The structure is defined in linux/in6.h since its max size is sized based on sockaddr_in6 and provides a more specific alternative to the generic sockaddr_storage for IPv4 with IPv6 address family handling. The "sa_family" member doesn't use the sa_family_t type to avoid needing layer violating header inclusions. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20250722171836.1078436-1-kees@kernel.org Signed-off-by: Jakub Kicinski

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

ipv6: by default join ff01::1 and in case of forwarding ff01::2 and ff05:2

2013-02-11T19:16:26+00:00

Cc: Erik Hugne Cc: YOSHIFUJI Hideaki Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

ipv6: Move comment to right place.

2013-01-14T02:04:37+00:00

IN6ADDR_* and in6addr_* are not exported to userspace, and are defined in include/linux/in6.h. Signed-off-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller

UAPI: (Scripted) Disintegrate include/linux

2012-10-13T09:46:48+00:00

Signed-off-by: David Howells Acked-by: Arnd Bergmann Acked-by: Thomas Gleixner Acked-by: Michael Kerrisk Acked-by: Paul E. McKenney Acked-by: Dave Jones

ipv6: correct the ipv6 option name - Pad0 to Pad1

2012-05-17T19:49:51+00:00

The padding destination or hop-by-hop option is called Pad1 and not Pad0. See RFC2460 (4.2) or the IANA ipv6-parameters registry: http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xml Signed-off-by: Eldad Zack Signed-off-by: David S. Miller

ipv6: Implement IPV6_UNICAST_IF socket option.

2012-02-08T20:52:45+00:00

The IPV6_UNICAST_IF feature is the IPv6 compliment to IP_UNICAST_IF. Signed-off-by: Erich E. Hoover Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tproxy: added tproxy sockopt interface in the IPV6 layer

2010-10-21T14:08:28+00:00

Support for IPV6_RECVORIGDSTADDR sockopt for UDP sockets were contributed by Harry Mason. Signed-off-by: Balazs Scheidler Signed-off-by: KOVACS Krisztian Signed-off-by: Patrick McHardy

IPv6: data structure changes for new socket options

2010-04-24T06:35:28+00:00

Add underlying data structure changes and basic setsockopt() and getsockopt() support for IPV6_RECVPATHMTU, IPV6_PATHMTU, and IPV6_DONTFRAG. IPV6_PATHMTU is actually fully functional at this point. Signed-off-by: Brian Haley Signed-off-by: David S. Miller

IPv6: Generic TTL Security Mechanism (final version)

2010-04-22T22:24:53+00:00

This patch adds IPv6 support for RFC5082 Generalized TTL Security Mechanism. Not to users of mapped address; the IPV6 and IPV4 socket options are seperate. The server does have to deal with both IPv4 and IPv6 socket options and the client has to handle the different for each family. On client: int ttl = 255; getaddrinfo(argv[1], argv[2], &hint, &result); for (rp = result; rp != NULL; rp = rp->ai_next) { s = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (s < 0) continue; if (rp->ai_family == AF_INET) { setsockopt(s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); } else if (rp->ai_family == AF_INET6) { setsockopt(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) } if (connect(s, rp->ai_addr, rp->ai_addrlen) == 0) { ... On server: int minttl = 255 - maxhops; getaddrinfo(NULL, port, &hints, &result); for (rp = result; rp != NULL; rp = rp->ai_next) { s = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol); if (s < 0) continue; if (rp->ai_family == AF_INET6) setsockopt(s, IPPROTO_IPV6, IPV6_MINHOPCOUNT, &minttl, sizeof(minttl)); setsockopt(s, IPPROTO_IP, IP_MINTTL, &minttl, sizeof(minttl)); if (bind(s, rp->ai_addr, rp->ai_addrlen) == 0) break ... Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller