diff options
| author | Jacques de Laval <Jacques.De.Laval@westermo.com> | 2022-02-17 16:02:02 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-18 21:20:06 -0800 |
| commit | 47f0bd5032106469827cf56c8b45bb9101112105 (patch) | |
| tree | c2f27dd7b1072733b0abd260e4104870bc9ac365 /net/ipv4 | |
| parent | 6e2e59eaee47f84d0ae6cc114d0fa8140dc17003 (diff) | |
net: Add new protocol attribute to IP addresses
This patch adds a new protocol attribute to IPv4 and IPv6 addresses.
Inspiration was taken from the protocol attribute of routes. User space
applications like iproute2 can set/get the protocol with the Netlink API.
The attribute is stored as an 8-bit unsigned integer.
The protocol attribute is set by kernel for these categories:
- IPv4 and IPv6 loopback addresses
- IPv6 addresses generated from router announcements
- IPv6 link local addresses
User space may pass custom protocols, not defined by the kernel.
Grouping addresses on their origin is useful in scenarios where you want
to distinguish between addresses based on who added them, e.g. kernel
vs. user space.
Tagging addresses with a string label is an existing feature that could be
used as a solution. Unfortunately the max length of a label is
15 characters, and for compatibility reasons the label must be prefixed
with the name of the device followed by a colon. Since device names also
have a max length of 15 characters, only -1 characters is guaranteed to be
available for any origin tag, which is not that much.
A reference implementation of user space setting and getting protocols
is available for iproute2:
https://github.com/westermo/iproute2/commit/9a6ea18bd79f47f293e5edc7780f315ea42ff540
Signed-off-by: Jacques de Laval <Jacques.De.Laval@westermo.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/devinet.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index fba2bffd65f7..53a6b14dc50a 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -104,6 +104,7 @@ static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = { [IFA_FLAGS] = { .type = NLA_U32 }, [IFA_RT_PRIORITY] = { .type = NLA_U32 }, [IFA_TARGET_NETNSID] = { .type = NLA_S32 }, + [IFA_PROTO] = { .type = NLA_U8 }, }; struct inet_fill_args { @@ -889,6 +890,9 @@ static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh, if (tb[IFA_RT_PRIORITY]) ifa->ifa_rt_priority = nla_get_u32(tb[IFA_RT_PRIORITY]); + if (tb[IFA_PROTO]) + ifa->ifa_proto = nla_get_u8(tb[IFA_PROTO]); + if (tb[IFA_CACHEINFO]) { struct ifa_cacheinfo *ci; @@ -1625,6 +1629,7 @@ static size_t inet_nlmsg_size(void) + nla_total_size(4) /* IFA_BROADCAST */ + nla_total_size(IFNAMSIZ) /* IFA_LABEL */ + nla_total_size(4) /* IFA_FLAGS */ + + nla_total_size(1) /* IFA_PROTO */ + nla_total_size(4) /* IFA_RT_PRIORITY */ + nla_total_size(sizeof(struct ifa_cacheinfo)); /* IFA_CACHEINFO */ } @@ -1699,6 +1704,8 @@ static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa, nla_put_in_addr(skb, IFA_BROADCAST, ifa->ifa_broadcast)) || (ifa->ifa_label[0] && nla_put_string(skb, IFA_LABEL, ifa->ifa_label)) || + (ifa->ifa_proto && + nla_put_u8(skb, IFA_PROTO, ifa->ifa_proto)) || nla_put_u32(skb, IFA_FLAGS, ifa->ifa_flags) || (ifa->ifa_rt_priority && nla_put_u32(skb, IFA_RT_PRIORITY, ifa->ifa_rt_priority)) || |