kernel/linux.git/include/uapi/linux/in6.h, branch v6.6.132

uapi: in6: restore visibility of most IPv6 socket options

2025-08-28T14:28:24+00:00

[ Upstream commit 31557b3487b349464daf42bc4366153743c1e727 ] A decade ago commit 6d08acd2d32e ("in6: fix conflict with glibc") hid the definitions of IPV6 options, because GCC was complaining about duplicates. The commit did not list the warnings seen, but trying to recreate them now I think they are (building iproute2): In file included from ./include/uapi/rdma/rdma_user_cm.h:39, from rdma.h:16, from res.h:9, from res-ctx.c:7: ../include/uapi/linux/in6.h:171:9: warning: ‘IPV6_ADD_MEMBERSHIP’ redefined 171 | #define IPV6_ADD_MEMBERSHIP 20 | ^~~~~~~~~~~~~~~~~~~ In file included from /usr/include/netinet/in.h:37, from rdma.h:13: /usr/include/bits/in.h:233:10: note: this is the location of the previous definition 233 | # define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP | ^~~~~~~~~~~~~~~~~~~ ../include/uapi/linux/in6.h:172:9: warning: ‘IPV6_DROP_MEMBERSHIP’ redefined 172 | #define IPV6_DROP_MEMBERSHIP 21 | ^~~~~~~~~~~~~~~~~~~~ /usr/include/bits/in.h:234:10: note: this is the location of the previous definition 234 | # define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP | ^~~~~~~~~~~~~~~~~~~~ Compilers don't complain about redefinition if the defines are identical, but here we have the kernel using the literal value, and glibc using an indirection (defining to a name of another define, with the same numerical value). Problem is, the commit in question hid all the IPV6 socket options, and glibc has a pretty sparse list. For instance it lacks Flow Label related options. Willem called this out in commit 3fb321fde22d ("selftests/net: ipv6 flowlabel"): /* uapi/glibc weirdness may leave this undefined */ #ifndef IPV6_FLOWINFO #define IPV6_FLOWINFO 11 #endif More interestingly some applications (socat) use a #ifdef IPV6_FLOWINFO to gate compilation of thier rudimentary flow label support. (For added confusion socat misspells it as IPV4_FLOWINFO in some places.) Hide only the two defines we know glibc has a problem with. If we discover more warnings we can hide more but we should avoid covering the entire block of defines for "IPV6 socket options". Link: https://patch.msgid.link/20250609143933.1654417-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

uapi: in6: replace temporary label with rfc9486

2024-03-06T14:48:35+00:00

[ Upstream commit 6a2008641920a9c6fe1abbeb9acbec463215d505 ] Not really a fix per se, but IPV6_TLV_IOAM is still tagged as "TEMPORARY IANA allocation for IOAM", while RFC 9486 is available for some time now. Just update the reference. Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Signed-off-by: Justin Iurman Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20240226124921.9097-1-justin.iurman@uliege.be Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv6: ioam: Data plane support for Pre-allocated Trace

2021-07-21T15:14:33+00:00

Implement support for processing the IOAM Pre-allocated Trace with IPv6, see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA [3]. A new per-interface sysctl is introduced. The value is a boolean to accept (=1) or ignore (=0, by default) IPv6 IOAM options on ingress for an interface: - net.ipv6.conf.XXX.ioam6_enabled Two other sysctls are introduced to define IOAM IDs, represented by an integer. They are respectively per-namespace and per-interface: - net.ipv6.ioam6_id - net.ipv6.conf.XXX.ioam6_id The value of the first one represents the IOAM ID of the node itself (u32; max and default value = U32_MAX>>8, due to hop limit concatenation) while the other represents the IOAM ID of an interface (u16; max and default value = U16_MAX). Each "ioam6_id" sysctl has a "_wide" equivalent: - net.ipv6.ioam6_id_wide - net.ipv6.conf.XXX.ioam6_id_wide The value of the first one represents the wide IOAM ID of the node itself (u64; max and default value = U64_MAX>>8, due to hop limit concatenation) while the other represents the wide IOAM ID of an interface (u32; max and default value = U32_MAX). The use of short and wide equivalents is not exclusive, a deployment could choose to leverage both. For example, net.ipv6.conf.XXX.ioam6_id (short format) could be an identifier for a physical interface, whereas net.ipv6.conf.XXX.ioam6_id_wide (wide format) could be an identifier for a logical sub-interface. Documentation about new sysctls is provided at the end of this patchset. Two relativistic hash tables are used: one for IOAM namespaces, the other for IOAM schemas. A namespace can only have a single active schema and a schema can only be attached to a single namespace (1:1 relationship). [1] https://tools.ietf.org/html/draft-ietf-ippm-ioam-ipv6-options [2] https://tools.ietf.org/html/draft-ietf-ippm-ioam-data [3] https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2 Signed-off-by: Justin Iurman Signed-off-by: David S. Miller

icmp6: support rfc 4884

2020-07-25T00:12:41+00:00

Extend the rfc 4884 read interface introduced for ipv4 in commit eba75c587e81 ("icmp: support rfc 4884") to ipv6. Add socket option SOL_IPV6/IPV6_RECVERR_RFC4884. Changes v1->v2: - make ipv6_icmp_error_rfc4884 static (file scope) Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

net: ipv6: add socket option IPV6_ROUTER_ALERT_ISOLATE

2019-03-04T05:05:10+00:00

By default IPv6 socket with IPV6_ROUTER_ALERT socket option set will receive all IPv6 RA packets from all namespaces. IPV6_ROUTER_ALERT_ISOLATE socket option restricts packets received by the socket to be only from the socket's namespace. Signed-off-by: Maxim Martynov Signed-off-by: Francesco Ruggeri Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: Add sockopt IPV6_MULTICAST_ALL analogue to IP_MULTICAST_ALL

2018-09-13T15:17:27+00:00

The socket option will be enabled by default to ensure current behaviour is not changed. This is the same for the IPv4 version. A socket bound to in6addr_any and a specific port will receive all traffic on that port. Analogue to IP_MULTICAST_ALL, disable this behaviour, if one or more multicast groups were joined (using said socket) and only pass on multicast traffic from groups, which were explicitly joined via this socket. Without this option disabled a socket (system even) joined to multiple multicast groups is very hard to get right. Filtering by destination address has to take place in user space to avoid receiving multicast traffic from other multicast groups, which might have traffic on the same port. The extension of the IP_MULTICAST_ALL socketoption to just apply to ipv6, too, is not done to avoid changing the behaviour of current applications. Signed-off-by: Andre Naujoks Acked-By: YOSHIFUJI Hideaki Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-11-04T00:26:51+00:00

Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11+00:00

Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

net-ipv6: add support for sockopt(SOL_IPV6, IPV6_FREEBIND)

2017-09-30T04:30:52+00:00

So far we've been relying on sockopt(SOL_IP, IP_FREEBIND) being usable even on IPv6 sockets. However, it turns out it is perfectly reasonable to want to set freebind on an AF_INET6 SOCK_RAW socket - but there is no way to set any SOL_IP socket option on such a socket (they're all blindly errored out). One use case for this is to allow spoofing src ip on a raw socket via sendmsg cmsg. Tested: built, and booted # python >>> import socket >>> SOL_IP = socket.SOL_IP >>> SOL_IPV6 = socket.IPPROTO_IPV6 >>> IP_FREEBIND = 15 >>> IPV6_FREEBIND = 78 >>> s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM, 0) >>> s.getsockopt(SOL_IP, IP_FREEBIND) 0 >>> s.getsockopt(SOL_IPV6, IPV6_FREEBIND) 0 >>> s.setsockopt(SOL_IPV6, IPV6_FREEBIND, 1) >>> s.getsockopt(SOL_IP, IP_FREEBIND) 1 >>> s.getsockopt(SOL_IPV6, IPV6_FREEBIND) 1 Signed-off-by: Maciej Żenczykowski Signed-off-by: David S. Miller

ipv6: add IPV6_RECVFRAGSIZE cmsg

2016-11-03T19:41:11+00:00

When reading a datagram or raw packet that arrived fragmented, expose the maximum fragment size if recorded to allow applications to estimate receive path MTU. At this point, the field is only recorded when ipv6 connection tracking is enabled. A follow-up patch will record this field also in the ipv6 input path. Tested using the test for IP_RECVFRAGSIZE plus ip netns exec to ip addr add dev veth1 fc07::1/64 ip netns exec from ip addr add dev veth0 fc07::2/64 ip netns exec to ./recv_cmsg_recvfragsize -6 -u -p 6000 & ip netns exec from nc -q 1 -u fc07::1 6000 < payload Both with and without enabling connection tracking ip6tables -A INPUT -m state --state NEW -p udp -j LOG Signed-off-by: Willem de Bruijn Acked-by: Eric Dumazet Signed-off-by: David S. Miller