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| author | Guillaume Nault <gnault@redhat.com> | 2024-12-16 20:21:44 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-21 00:50:09 +0300 |
| commit | 1dbdce30f040a87f5aa6a9dbe43be398737f090f (patch) | |
| tree | c171045b99d5d3940b8635e974a32f25867511a2 /include/net/route.h | |
| parent | 6ed3472173c575cd8aaed6c62eb74f7728404ee6 (diff) | |
| download | linux-1dbdce30f040a87f5aa6a9dbe43be398737f090f.tar.xz | |
ipv4: Define inet_sk_init_flowi4() and use it in inet_sk_rebuild_header().
IPv4 code commonly has to initialise a flowi4 structure from an IPv4
socket. This requires looking at potential IPv4 options to set the
proper destination address, call flowi4_init_output() with the correct
set of parameters and run the sk_classify_flow security hook.
Instead of reimplementing these operations in different parts of the
stack, let's define inet_sk_init_flowi4() which does all these
operations.
The first user is inet_sk_rebuild_header(), where inet_sk_init_flowi4()
replaces ip_route_output_ports(). Unlike ip_route_output_ports(), which
sets the flowi4 structure and performs the route lookup in one go,
inet_sk_init_flowi4() only initialises the flow. The route lookup is
then done by ip_route_output_flow(). Decoupling flow initialisation
from route lookup makes this new interface applicable more broadly as
it will allow some users to overwrite specific struct flowi4 members
before the route lookup.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/fd416275262b1f518d5abfcef740ce4f4a1a6522.1734357769.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net/route.h')
| -rw-r--r-- | include/net/route.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/net/route.h b/include/net/route.h index 6947a155d501..f86775be3e29 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -28,6 +28,7 @@ #include <net/arp.h> #include <net/ndisc.h> #include <net/inet_dscp.h> +#include <net/sock.h> #include <linux/in_route.h> #include <linux/rtnetlink.h> #include <linux/rcupdate.h> @@ -129,6 +130,33 @@ struct in_device; int ip_rt_init(void); void rt_cache_flush(struct net *net); void rt_flush_dev(struct net_device *dev); + +static inline void inet_sk_init_flowi4(const struct inet_sock *inet, + struct flowi4 *fl4) +{ + const struct ip_options_rcu *ip4_opt; + const struct sock *sk; + __be32 daddr; + + rcu_read_lock(); + ip4_opt = rcu_dereference(inet->inet_opt); + + /* Source routing option overrides the socket destination address */ + if (ip4_opt && ip4_opt->opt.srr) + daddr = ip4_opt->opt.faddr; + else + daddr = inet->inet_daddr; + rcu_read_unlock(); + + sk = &inet->sk; + flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), + ip_sock_rt_tos(sk), ip_sock_rt_scope(sk), + sk->sk_protocol, inet_sk_flowi_flags(sk), daddr, + inet->inet_saddr, inet->inet_dport, + inet->inet_sport, sk->sk_uid); + security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); +} + struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp, const struct sk_buff *skb); struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp, |