diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2025-09-16 17:09:36 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-09-18 12:32:06 +0200 |
| commit | e97269257fe437910cddc7c642a636ca3cf9fb1d (patch) | |
| tree | 6a45064cf93eea7adb04dbfcc2b4af632aa2e351 /include/net | |
| parent | net: psp: add socket security association code (diff) | |
| download | linux-e97269257fe437910cddc7c642a636ca3cf9fb1d.tar.gz linux-e97269257fe437910cddc7c642a636ca3cf9fb1d.zip | |
net: psp: update the TCP MSS to reflect PSP packet overhead
PSP eats 40B of header space. Adjust MSS appropriately.
We can either modify tcp_mtu_to_mss() / tcp_mss_to_mtu()
or reuse icsk_ext_hdr_len. The former option is more TCP
specific and has runtime overhead. The latter is a bit
of a hack as PSP is not an ext_hdr. If one squints hard
enough, UDP encap is just a more practical version of
IPv6 exthdr, so go with the latter. Happy to change.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250917000954.859376-10-daniel.zahka@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/psp/functions.h | 14 | ||||
| -rw-r--r-- | include/net/psp/types.h | 3 |
2 files changed, 17 insertions, 0 deletions
diff --git a/include/net/psp/functions.h b/include/net/psp/functions.h index 0d7141230f47..183a3c9216b7 100644 --- a/include/net/psp/functions.h +++ b/include/net/psp/functions.h @@ -5,6 +5,7 @@ #include <linux/skbuff.h> #include <linux/rcupdate.h> +#include <linux/udp.h> #include <net/sock.h> #include <net/tcp.h> #include <net/psp/types.h> @@ -143,6 +144,14 @@ static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb) return psp_sk_get_assoc_rcu(skb->sk); } + +static inline unsigned int psp_sk_overhead(const struct sock *sk) +{ + int psp_encap = sizeof(struct udphdr) + PSP_HDR_SIZE + PSP_TRL_SIZE; + bool has_psp = rcu_access_pointer(sk->psp_assoc); + + return has_psp ? psp_encap : 0; +} #else static inline void psp_sk_assoc_free(struct sock *sk) { } static inline void @@ -182,6 +191,11 @@ static inline struct psp_assoc *psp_skb_get_assoc_rcu(struct sk_buff *skb) { return NULL; } + +static inline unsigned int psp_sk_overhead(const struct sock *sk) +{ + return 0; +} #endif static inline unsigned long diff --git a/include/net/psp/types.h b/include/net/psp/types.h index b0e32e7165a3..f93ad0e6c04f 100644 --- a/include/net/psp/types.h +++ b/include/net/psp/types.h @@ -93,6 +93,9 @@ struct psp_dev_caps { #define PSP_MAX_KEY 32 +#define PSP_HDR_SIZE 16 /* We don't support optional fields, yet */ +#define PSP_TRL_SIZE 16 /* AES-GCM/GMAC trailer size */ + struct psp_skb_ext { __be32 spi; u16 dev_id; |