passt/tcp.h
David Gibson ee8f8e9564 tcp: Unify spliced and non-spliced connection tables
Currently spliced and non-spliced connections are stored in completely
separate tables, so there are completely independent limits on the number
of spliced and non-spliced connections.  This is a bit counter-intuitive.

More importantly, the fact that the tables are separate prevents us from
unifying some other logic between the two cases.  So, merge these two
tables into one, using the 'c.spliced' common field to distinguish between
them when necessary.

For now we keep a common limit of 128k connections, whether they're spliced
or non-spliced, which means we save memory overall.  If necessary we could
increase this to a 256k or higher total, which would cost memory but give
some more flexibility.

For now, the code paths which need to step through all extant connections
are still separate for the two cases, just skipping over entries which
aren't for them.  We'll improve that in later patches.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-11-25 01:34:51 +01:00

79 lines
2.5 KiB
C

/* SPDX-License-Identifier: AGPL-3.0-or-later
* Copyright (c) 2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#ifndef TCP_H
#define TCP_H
#define TCP_TIMER_INTERVAL 1000 /* ms */
#define TCP_CONN_INDEX_BITS 17 /* 128k */
#define TCP_MAX_CONNS (1 << TCP_CONN_INDEX_BITS)
#define TCP_SOCK_POOL_SIZE 32
struct ctx;
void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
const struct timespec *now);
int tcp_tap_handler(struct ctx *c, int af, const void *addr,
const struct pool *p, const struct timespec *now);
void tcp_sock_init(const struct ctx *c, int ns, sa_family_t af,
const void *addr, const char *ifname, in_port_t port);
int tcp_init(struct ctx *c);
void tcp_timer(struct ctx *c, const struct timespec *ts);
void tcp_defer_handler(struct ctx *c);
void tcp_sock_set_bufsize(const struct ctx *c, int s);
void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
const struct in_addr *ip_da);
/**
* union tcp_epoll_ref - epoll reference portion for TCP connections
* @listen: Set if this file descriptor is a listening socket
* @splice: Set if descriptor is associated to a spliced connection
* @outbound: Listening socket maps to outbound, spliced connection
* @v6: Set for IPv6 sockets or connections
* @timer: Reference is a timerfd descriptor for connection
* @index: Index of connection in table, or port for bound sockets
* @u32: Opaque u32 value of reference
*/
union tcp_epoll_ref {
struct {
uint32_t listen:1,
splice:1,
outbound:1,
v6:1,
timer:1,
index:20;
} tcp;
uint32_t u32;
};
/**
* struct tcp_ctx - Execution context for TCP routines
* @hash_secret: 128-bit secret for hash functions, ISN and hash table
* @conn_count: Count of total connections in connection table
* @splice_conn_count: Count of spliced connections in connection table
* @port_to_tap: Ports bound host-side, packets to tap or spliced
* @fwd_in: Port forwarding configuration for inbound packets
* @fwd_out: Port forwarding configuration for outbound packets
* @timer_run: Timestamp of most recent timer run
* @kernel_snd_wnd: Kernel reports sending window (with commit 8f7baad7f035)
* @pipe_size: Size of pipes for spliced connections
*/
struct tcp_ctx {
uint64_t hash_secret[2];
int conn_count;
int splice_conn_count;
struct port_fwd fwd_in;
struct port_fwd fwd_out;
struct timespec timer_run;
#ifdef HAS_SND_WND
int kernel_snd_wnd;
#endif
size_t pipe_size;
};
#endif /* TCP_H */