linux/net/netfilter/ipvs/ip_vs_proto_sctp.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/ip.h>
#include <linux/sctp.h>
#include <net/ip.h>
#include <net/ip6_checksum.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <net/sctp/checksum.h>
#include <net/ip_vs.h>

static int
sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp);

static int
sctp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
		   struct ip_vs_proto_data *pd,
		   int *verdict, struct ip_vs_conn **cpp,
		   struct ip_vs_iphdr *iph)
{ … }

static void sctp_nat_csum(struct sk_buff *skb, struct sctphdr *sctph,
			  unsigned int sctphoff)
{ … }

static int
sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
		  struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
{ … }

static int
sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
		  struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
{ … }

static int
sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
{ … }

enum ipvs_sctp_event_t { … };

/* RFC 2960, 3.2 Chunk Field Descriptions */
static __u8 sctp_events[] = …;

/* SCTP States:
 * See RFC 2960, 4. SCTP Association State Diagram
 *
 * New states (not in diagram):
 * - INIT1 state: use shorter timeout for dropped INIT packets
 * - REJECTED state: use shorter timeout if INIT is rejected with ABORT
 * - INIT, COOKIE_SENT, COOKIE_REPLIED, COOKIE states: for better debugging
 *
 * The states are as seen in real server. In the diagram, INIT1, INIT,
 * COOKIE_SENT and COOKIE_REPLIED processing happens in CLOSED state.
 *
 * States as per packets from client (C) and server (S):
 *
 * Setup of client connection:
 * IP_VS_SCTP_S_INIT1: First C:INIT sent, wait for S:INIT-ACK
 * IP_VS_SCTP_S_INIT: Next C:INIT sent, wait for S:INIT-ACK
 * IP_VS_SCTP_S_COOKIE_SENT: S:INIT-ACK sent, wait for C:COOKIE-ECHO
 * IP_VS_SCTP_S_COOKIE_REPLIED: C:COOKIE-ECHO sent, wait for S:COOKIE-ACK
 *
 * Setup of server connection:
 * IP_VS_SCTP_S_COOKIE_WAIT: S:INIT sent, wait for C:INIT-ACK
 * IP_VS_SCTP_S_COOKIE: C:INIT-ACK sent, wait for S:COOKIE-ECHO
 * IP_VS_SCTP_S_COOKIE_ECHOED: S:COOKIE-ECHO sent, wait for C:COOKIE-ACK
 */

#define sNO …
#define sI1 …
#define sIN …
#define sCS …
#define sCR …
#define sCW …
#define sCO …
#define sCE …
#define sES …
#define sSS …
#define sSR …
#define sSA …
#define sRJ …
#define sCL …

static const __u8 sctp_states
	[IP_VS_DIR_LAST][IP_VS_SCTP_EVENT_LAST][IP_VS_SCTP_S_LAST] = …;

#define IP_VS_SCTP_MAX_RTO …

/* Timeout table[state] */
static const int sctp_timeouts[IP_VS_SCTP_S_LAST + 1] = …;

static const char *sctp_state_name_table[IP_VS_SCTP_S_LAST + 1] = …;


static const char *sctp_state_name(int state)
{ … }

static inline void
set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
		int direction, const struct sk_buff *skb)
{ … }

static void
sctp_state_transition(struct ip_vs_conn *cp, int direction,
		const struct sk_buff *skb, struct ip_vs_proto_data *pd)
{ … }

static inline __u16 sctp_app_hashkey(__be16 port)
{ … }

static int sctp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
{ … }

static void sctp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
{ … }

static int sctp_app_conn_bind(struct ip_vs_conn *cp)
{ … }

/* ---------------------------------------------
 *   timeouts is netns related now.
 * ---------------------------------------------
 */
static int __ip_vs_sctp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
{ … }

static void __ip_vs_sctp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
{ … }

struct ip_vs_protocol ip_vs_protocol_sctp = …;