linux-stable/include/net/mptcp.h
Matthieu Baerts 3fff88186f mptcp: remove MPTCP 'ifdef' in TCP SYN cookies
To ease the maintenance, it is often recommended to avoid having #ifdef
preprocessor conditions.

Here the section related to CONFIG_MPTCP was quite short but the next
commit needs to add more code around. It is then cleaner to move
specific MPTCP code to functions located in net/mptcp directory.

Now that mptcp_subflow_request_sock_ops structure can be static, it can
also be marked as "read only after init".

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-12 13:11:24 -08:00

306 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Multipath TCP
*
* Copyright (c) 2017 - 2019, Intel Corporation.
*/
#ifndef __NET_MPTCP_H
#define __NET_MPTCP_H
#include <linux/skbuff.h>
#include <linux/tcp.h>
#include <linux/types.h>
struct mptcp_info;
struct mptcp_sock;
struct seq_file;
/* MPTCP sk_buff extension data */
struct mptcp_ext {
union {
u64 data_ack;
u32 data_ack32;
};
u64 data_seq;
u32 subflow_seq;
u16 data_len;
__sum16 csum;
u8 use_map:1,
dsn64:1,
data_fin:1,
use_ack:1,
ack64:1,
mpc_map:1,
frozen:1,
reset_transient:1;
u8 reset_reason:4,
csum_reqd:1,
infinite_map:1;
};
#define MPTCPOPT_HMAC_LEN 20
#define MPTCP_RM_IDS_MAX 8
struct mptcp_rm_list {
u8 ids[MPTCP_RM_IDS_MAX];
u8 nr;
};
struct mptcp_addr_info {
u8 id;
sa_family_t family;
__be16 port;
union {
struct in_addr addr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
struct in6_addr addr6;
#endif
};
};
struct mptcp_out_options {
#if IS_ENABLED(CONFIG_MPTCP)
u16 suboptions;
struct mptcp_rm_list rm_list;
u8 join_id;
u8 backup;
u8 reset_reason:4,
reset_transient:1,
csum_reqd:1,
allow_join_id0:1;
union {
struct {
u64 sndr_key;
u64 rcvr_key;
u64 data_seq;
u32 subflow_seq;
u16 data_len;
__sum16 csum;
};
struct {
struct mptcp_addr_info addr;
u64 ahmac;
};
struct {
struct mptcp_ext ext_copy;
u64 fail_seq;
};
struct {
u32 nonce;
u32 token;
u64 thmac;
u8 hmac[MPTCPOPT_HMAC_LEN];
};
};
#endif
};
#ifdef CONFIG_MPTCP
void mptcp_init(void);
static inline bool sk_is_mptcp(const struct sock *sk)
{
return tcp_sk(sk)->is_mptcp;
}
static inline bool rsk_is_mptcp(const struct request_sock *req)
{
return tcp_rsk(req)->is_mptcp;
}
static inline bool rsk_drop_req(const struct request_sock *req)
{
return tcp_rsk(req)->is_mptcp && tcp_rsk(req)->drop_req;
}
void mptcp_space(const struct sock *ssk, int *space, int *full_space);
bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
unsigned int *size, struct mptcp_out_options *opts);
bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
struct mptcp_out_options *opts);
bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
unsigned int *size, unsigned int remaining,
struct mptcp_out_options *opts);
bool mptcp_incoming_options(struct sock *sk, struct sk_buff *skb);
void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
struct mptcp_out_options *opts);
void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info);
/* move the skb extension owership, with the assumption that 'to' is
* newly allocated
*/
static inline void mptcp_skb_ext_move(struct sk_buff *to,
struct sk_buff *from)
{
if (!skb_ext_exist(from, SKB_EXT_MPTCP))
return;
if (WARN_ON_ONCE(to->active_extensions))
skb_ext_put(to);
to->active_extensions = from->active_extensions;
to->extensions = from->extensions;
from->active_extensions = 0;
}
static inline void mptcp_skb_ext_copy(struct sk_buff *to,
struct sk_buff *from)
{
struct mptcp_ext *from_ext;
from_ext = skb_ext_find(from, SKB_EXT_MPTCP);
if (!from_ext)
return;
from_ext->frozen = 1;
skb_ext_copy(to, from);
}
static inline bool mptcp_ext_matches(const struct mptcp_ext *to_ext,
const struct mptcp_ext *from_ext)
{
/* MPTCP always clears the ext when adding it to the skb, so
* holes do not bother us here
*/
return !from_ext ||
(to_ext && from_ext &&
!memcmp(from_ext, to_ext, sizeof(struct mptcp_ext)));
}
/* check if skbs can be collapsed.
* MPTCP collapse is allowed if neither @to or @from carry an mptcp data
* mapping, or if the extension of @to is the same as @from.
* Collapsing is not possible if @to lacks an extension, but @from carries one.
*/
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return mptcp_ext_matches(skb_ext_find(to, SKB_EXT_MPTCP),
skb_ext_find(from, SKB_EXT_MPTCP));
}
void mptcp_seq_show(struct seq_file *seq);
int mptcp_subflow_init_cookie_req(struct request_sock *req,
const struct sock *sk_listener,
struct sk_buff *skb);
struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
struct sock *sk_listener,
bool attach_listener);
__be32 mptcp_get_reset_option(const struct sk_buff *skb);
static inline __be32 mptcp_reset_option(const struct sk_buff *skb)
{
if (skb_ext_exist(skb, SKB_EXT_MPTCP))
return mptcp_get_reset_option(skb);
return htonl(0u);
}
#else
static inline void mptcp_init(void)
{
}
static inline bool sk_is_mptcp(const struct sock *sk)
{
return false;
}
static inline bool rsk_is_mptcp(const struct request_sock *req)
{
return false;
}
static inline bool rsk_drop_req(const struct request_sock *req)
{
return false;
}
static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
unsigned int *size,
struct mptcp_out_options *opts)
{
return false;
}
static inline bool mptcp_synack_options(const struct request_sock *req,
unsigned int *size,
struct mptcp_out_options *opts)
{
return false;
}
static inline bool mptcp_established_options(struct sock *sk,
struct sk_buff *skb,
unsigned int *size,
unsigned int remaining,
struct mptcp_out_options *opts)
{
return false;
}
static inline bool mptcp_incoming_options(struct sock *sk,
struct sk_buff *skb)
{
return true;
}
static inline void mptcp_skb_ext_move(struct sk_buff *to,
const struct sk_buff *from)
{
}
static inline void mptcp_skb_ext_copy(struct sk_buff *to,
struct sk_buff *from)
{
}
static inline bool mptcp_skb_can_collapse(const struct sk_buff *to,
const struct sk_buff *from)
{
return true;
}
static inline void mptcp_space(const struct sock *ssk, int *s, int *fs) { }
static inline void mptcp_seq_show(struct seq_file *seq) { }
static inline int mptcp_subflow_init_cookie_req(struct request_sock *req,
const struct sock *sk_listener,
struct sk_buff *skb)
{
return 0; /* TCP fallback */
}
static inline struct request_sock *mptcp_subflow_reqsk_alloc(const struct request_sock_ops *ops,
struct sock *sk_listener,
bool attach_listener)
{
return NULL;
}
static inline __be32 mptcp_reset_option(const struct sk_buff *skb) { return htonl(0u); }
#endif /* CONFIG_MPTCP */
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
int mptcpv6_init(void);
void mptcpv6_handle_mapped(struct sock *sk, bool mapped);
#elif IS_ENABLED(CONFIG_IPV6)
static inline int mptcpv6_init(void) { return 0; }
static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
#endif
#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
#else
static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
#endif
#if !IS_ENABLED(CONFIG_MPTCP)
struct mptcp_sock { };
#endif
#endif /* __NET_MPTCP_H */