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/* $OpenBSD: pipex_local.h,v 1.25 2017/05/04 15:00:24 bluhm Exp $ */
/*
* Copyright (c) 2009 Internet Initiative Japan Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef __OpenBSD__
#define Static
#else
#define Static static
#endif
#define PIPEX_PPTP 1
#define PIPEX_L2TP 1
#define PIPEX_PPPOE 1
#define PIPEX_MPPE 1
#define PIPEX_REWIND_LIMIT 64
#define PIPEX_ENABLED 0x0001
/* compile time option constants */
#ifndef PIPEX_MAX_SESSION
#define PIPEX_MAX_SESSION 512
#endif
#define PIPEX_HASH_DIV 8
#define PIPEX_HASH_SIZE (PIPEX_MAX_SESSION/PIPEX_HASH_DIV)
#define PIPEX_HASH_MASK (PIPEX_HASH_SIZE-1)
#define PIPEX_CLOSE_TIMEOUT 30
#define PIPEX_PPPMINLEN 5
/* minimum PPP header length is 1 and minimum ppp payload length is 4 */
#ifndef NNBY /* usually defined on the <sys/types.h> */
#define NNBY 8 /* number of bits of a byte */
#endif
#define PIPEX_MPPE_NOLDKEY 64 /* should be power of two */
#define PIPEX_MPPE_OLDKEYMASK (PIPEX_MPPE_NOLDKEY - 1)
#ifdef PIPEX_MPPE
/* mppe rc4 key */
struct pipex_mppe {
int16_t stateless:1, /* key change mode */
resetreq:1,
reserved:14;
int16_t keylenbits; /* key length */
int16_t keylen;
uint16_t coher_cnt; /* cohency counter */
struct rc4_ctx rc4ctx;
u_char master_key[PIPEX_MPPE_KEYLEN]; /* master key of MPPE */
u_char session_key[PIPEX_MPPE_KEYLEN]; /* session key of MPPE */
u_char (*old_session_keys)[PIPEX_MPPE_KEYLEN]; /* old session keys */
};
#endif /* PIPEX_MPPE */
#ifdef PIPEX_PPPOE
struct pipex_pppoe_session {
struct ifnet *over_ifp; /* ether interface */
};
#endif /* PIPEX_PPPOE */
#ifdef PIPEX_PPTP
struct pipex_pptp_session {
/* sequence number gap between pipex and userland */
int32_t snd_gap; /* gap of our sequence */
int32_t rcv_gap; /* gap of peer's sequence */
int32_t ul_snd_una; /* userland send acked seq */
uint32_t snd_nxt; /* send next */
uint32_t rcv_nxt; /* receive next */
uint32_t snd_una; /* send acked sequence */
uint32_t rcv_acked; /* recv acked sequence */
int winsz; /* windows size */
int maxwinsz; /* max windows size */
int peer_maxwinsz; /* peer's max windows size */
};
#endif /* PIPEX_PPTP */
#ifdef PIPEX_L2TP
/*
* L2TP Packet headers
*
* +----+---+----+---+----+--------+
* |IPv4|UDP|L2TP|PPP|IPv4|Data....|
* +----+---+----+---+----+--------+
*
* Session Data
*
* IPv4 IP_SRC <-- required for encap.
* IP_DST <-- required for encap.
*
* UDP SPort <-- required for encap.
* DPort <-- required for encap.
*
* L2TP FLAGS <-- only handle TYPE=0 (data)
* Tunnel ID <-- ID per tunnel(NOT a key: differed from RFC)
* Session ID <-- ID per PPP session(KEY to look up session)
* Ns(SEND SEQ) <-- sequence number of packet to send(opt.)
* Nr(RECV SEQ) <-- sequence number of packet to recv(opt.)
*
* - Recv Session lookup key is (Tunnnel ID, Session ID) in RFC.
* - BUT (Session ID) in PIPEX. SESSION ID MUST BE UNIQ.
*
* - We must update (Ns, Nr) of data channel. and we must adjust (Ns, Nr)
* in packets from/to userland.
*/
struct pipex_l2tp_session {
/* KEYS for session lookup (host byte order) */
uint16_t tunnel_id; /* our tunnel-id */
uint16_t peer_tunnel_id; /* peer's tunnel-id */
/* protocol options */
uint32_t option_flags;
int16_t ns_gap; /* gap between userland and pipex */
int16_t nr_gap; /* gap between userland and pipex */
uint16_t ul_ns_una; /* unacked sequence number (userland) */
uint16_t ns_nxt; /* next sequence number to send */
uint16_t ns_una; /* unacked sequence number to send*/
uint16_t nr_nxt; /* next sequence number to recv */
uint16_t nr_acked; /* acked sequence number to recv */
uint32_t ipsecflowinfo; /* IPsec SA flow id for NAT-T */
};
#endif /* PIPEX_L2TP */
/* pppac ip-extension sessoin table */
struct pipex_session {
struct radix_node ps4_rn[2]; /* tree glue, and other values */
struct radix_node ps6_rn[2]; /* tree glue, and other values */
LIST_ENTRY(pipex_session) session_list; /* all session chain */
LIST_ENTRY(pipex_session) state_list; /* state list chain */
LIST_ENTRY(pipex_session) id_chain; /* id hash chain */
LIST_ENTRY(pipex_session) peer_addr_chain;
/* peer's address hash chain */
uint16_t state; /* pipex session state */
#define PIPEX_STATE_INITIAL 0x0000
#define PIPEX_STATE_OPENED 0x0001
#define PIPEX_STATE_CLOSE_WAIT 0x0002
#define PIPEX_STATE_CLOSE_WAIT2 0x0003
#define PIPEX_STATE_CLOSED 0x0004
uint16_t ip_forward:1, /* {en|dis}ableIP forwarding */
ip6_forward:1, /* {en|dis}able IPv6 forwarding */
is_multicast:1, /* virtual entry for multicast */
reserved:13;
uint16_t protocol; /* tunnel protocol (PK) */
uint16_t session_id; /* session-id (PK) */
uint16_t peer_session_id; /* peer's session-id */
uint16_t peer_mru; /* peer's MRU */
uint32_t timeout_sec; /* idle timeout */
int ppp_id; /* PPP id */
struct sockaddr_in ip_address; /* remote address (AK) */
struct sockaddr_in ip_netmask; /* remote address mask (AK) */
struct sockaddr_in6 ip6_address; /* remote IPv6 address */
int ip6_prefixlen; /* remote IPv6 prefixlen */
struct pipex_iface_context* pipex_iface;/* context for interface */
uint32_t ppp_flags; /* configure flags */
#ifdef PIPEX_MPPE
int ccp_id; /* CCP packet id */
struct pipex_mppe
mppe_recv, /* MPPE context for incoming */
mppe_send; /* MPPE context for outgoing */
#endif /*PIPEXMPPE */
struct pipex_statistics stat; /* statistics */
union {
#ifdef PIPEX_PPPOE
struct pipex_pppoe_session pppoe; /* context for PPPoE */
#endif /* PIPEX_PPPOE */
#ifdef PIPEX_PPTP
struct pipex_pptp_session pptp; /* context for PPTP */
#endif /* PIPEX_PPTP */
#ifdef PIPEX_L2TP
struct pipex_l2tp_session l2tp;
#endif
char _proto_unknown[0];
} proto;
union {
struct sockaddr sa;
struct sockaddr_in sin4;
struct sockaddr_in6 sin6;
struct sockaddr_dl sdl;
} peer, local;
};
/* gre header */
struct pipex_gre_header {
uint16_t flags; /* flags and version*/
#define PIPEX_GRE_KFLAG 0x2000 /* keys present */
#define PIPEX_GRE_SFLAG 0x1000 /* seq present */
#define PIPEX_GRE_AFLAG 0x0080 /* ack present */
#define PIPEX_GRE_VER 0x0001 /* gre version code */
#define PIPEX_GRE_VERMASK 0x0007 /* gre version mask */
#define PIPEX_GRE_UNUSEDFLAGS 0xcf78 /* unused at pptp. set 0 in rfc2637 */
uint16_t type;
#define PIPEX_GRE_PROTO_PPP 0x880b /* gre/ppp */
uint16_t len; /* length not include gre header */
uint16_t call_id; /* call_id */
} __packed;
/* pppoe header */
struct pipex_pppoe_header {
uint8_t vertype; /* version and type */
#define PIPEX_PPPOE_VERTYPE 0x11 /* version and type code */
uint8_t code; /* code */
#define PIPEX_PPPOE_CODE_SESSION 0x00 /* code session */
uint16_t session_id; /* session id */
uint16_t length; /* length */
} __packed;
/* l2tp header */
struct pipex_l2tp_header {
uint16_t flagsver;
#define PIPEX_L2TP_FLAG_MASK 0xfff0
#define PIPEX_L2TP_FLAG_TYPE 0x8000
#define PIPEX_L2TP_FLAG_LENGTH 0x4000
#define PIPEX_L2TP_FLAG_SEQUENCE 0x0800
#define PIPEX_L2TP_FLAG_OFFSET 0x0200
#define PIPEX_L2TP_FLAG_PRIORITY 0x0100
#define PIPEX_L2TP_VER_MASK 0x000f
#define PIPEX_L2TP_VER 2
uint16_t length; /* optional */
uint16_t tunnel_id;
uint16_t session_id;
/* can be followed by option header */
} __packed;
/* l2tp option header */
struct pipex_l2tp_seq_header {
uint16_t ns;
uint16_t nr;
} __packed;
struct pipex_l2tp_offset_header {
uint16_t offset_size;
/* uint8_t offset_pad[] */
} __packed;
#ifdef PIPEX_DEBUG
#define PIPEX_DBG(a) if (pipex_debug & 1) pipex_session_log a
/* #define PIPEX_MPPE_DBG(a) if (pipex_debug & 1) pipex_session_log a */
#define PIPEX_MPPE_DBG(a)
#else
#define PIPEX_DBG(a)
#define PIPEX_MPPE_DBG(a)
#endif /* PIPEX_DEBUG */
LIST_HEAD(pipex_hash_head, pipex_session);
extern struct pipex_hash_head pipex_session_list;
extern struct pipex_hash_head pipex_close_wait_list;
extern struct pipex_hash_head pipex_peer_addr_hashtable[];
extern struct pipex_hash_head pipex_id_hashtable[];
#define PIPEX_ID_HASHTABLE(key) \
(&pipex_id_hashtable[(key) & PIPEX_HASH_MASK])
#define PIPEX_PEER_ADDR_HASHTABLE(key) \
(&pipex_peer_addr_hashtable[(key) & PIPEX_HASH_MASK])
#define GETCHAR(c, cp) do { \
(c) = *(cp)++; \
} while (0)
#define PUTCHAR(s, cp) do { \
*(cp)++ = (u_char)(s); \
} while (0)
#define GETSHORT(s, cp) do { \
(s) = *(cp)++ << 8; \
(s) |= *(cp)++; \
} while (0)
#define PUTSHORT(s, cp) do { \
*(cp)++ = (u_char) ((s) >> 8); \
*(cp)++ = (u_char) (s); \
} while (0)
#define GETLONG(l, cp) do { \
(l) = *(cp)++ << 8; \
(l) |= *(cp)++; (l) <<= 8; \
(l) |= *(cp)++; (l) <<= 8; \
(l) |= *(cp)++; \
} while (0)
#define PUTLONG(l, cp) do { \
*(cp)++ = (u_char) ((l) >> 24); \
*(cp)++ = (u_char) ((l) >> 16); \
*(cp)++ = (u_char) ((l) >> 8); \
*(cp)++ = (u_char) (l); \
} while (0)
#define PIPEX_PULLUP(m0, l) \
if ((m0)->m_len < (l)) { \
if ((m0)->m_pkthdr.len < (l)) { \
PIPEX_DBG((NULL, LOG_DEBUG, \
"<%s> received packet is too short.", \
__func__)); \
m_freem(m0); \
(m0) = NULL; \
} else { \
(m0) = m_pullup((m0), (l)); \
KASSERT((m0) != NULL); \
} \
}
#define PIPEX_SEEK_NEXTHDR(ptr, len, t) \
((t) (((char *)ptr) + len))
#define SEQ32_LT(a,b) ((int)((a) - (b)) < 0)
#define SEQ32_LE(a,b) ((int)((a) - (b)) <= 0)
#define SEQ32_GT(a,b) ((int)((a) - (b)) > 0)
#define SEQ32_GE(a,b) ((int)((a) - (b)) >= 0)
#define SEQ32_SUB(a,b) ((int32_t)((a) - (b)))
#define SEQ16_LT(a,b) ((int)((a) - (b)) < 0)
#define SEQ16_LE(a,b) ((int)((a) - (b)) <= 0)
#define SEQ16_GT(a,b) ((int)((a) - (b)) > 0)
#define SEQ16_GE(a,b) ((int)((a) - (b)) >= 0)
#define SEQ16_SUB(a,b) ((int16_t)((a) - (b)))
#define pipex_session_is_acfc_accepted(s) \
(((s)->ppp_flags & PIPEX_PPP_ACFC_ACCEPTED)? 1 : 0)
#define pipex_session_is_pfc_accepted(s) \
(((s)->ppp_flags & PIPEX_PPP_PFC_ACCEPTED)? 1 : 0)
#define pipex_session_is_acfc_enabled(s) \
(((s)->ppp_flags & PIPEX_PPP_ACFC_ENABLED)? 1 : 0)
#define pipex_session_is_pfc_enabled(s) \
(((s)->ppp_flags & PIPEX_PPP_PFC_ENABLED)? 1 : 0)
#define pipex_session_has_acf(s) \
(((s)->ppp_flags & PIPEX_PPP_HAS_ACF)? 1 : 0)
#define pipex_session_is_mppe_accepted(s) \
(((s)->ppp_flags & PIPEX_PPP_MPPE_ACCEPTED)? 1 : 0)
#define pipex_session_is_mppe_enabled(s) \
(((s)->ppp_flags & PIPEX_PPP_MPPE_ENABLED)? 1 : 0)
#define pipex_session_is_mppe_required(s) \
(((s)->ppp_flags & PIPEX_PPP_MPPE_REQUIRED)? 1 : 0)
#define pipex_mppe_rc4_keybits(r) ((r)->keylen << 3)
#define pipex_session_is_l2tp_data_sequencing_on(s) \
(((s)->proto.l2tp.option_flags & PIPEX_L2TP_USE_SEQUENCING) ? 1 : 0)
#define PIPEX_IPGRE_HDRLEN (sizeof(struct ip) + sizeof(struct pipex_gre_header))
#define PIPEX_TCP_OPTLEN 40
#define PIPEX_L2TP_MINLEN 8
/*
* static function prototypes
*/
Static void pipex_iface_start (struct pipex_iface_context *);
Static void pipex_iface_stop (struct pipex_iface_context *);
Static int pipex_add_session (struct pipex_session_req *, struct pipex_iface_context *);
Static int pipex_close_session (struct pipex_session_close_req *);
Static int pipex_config_session (struct pipex_session_config_req *);
Static int pipex_get_stat (struct pipex_session_stat_req *);
Static int pipex_get_closed (struct pipex_session_list_req *);
Static int pipex_destroy_session (struct pipex_session *);
Static struct pipex_session *pipex_lookup_by_ip_address (struct in_addr);
Static struct pipex_session *pipex_lookup_by_session_id (int, int);
Static void pipex_ip_output (struct mbuf *, struct pipex_session *);
Static void pipex_ppp_output (struct mbuf *, struct pipex_session *, int);
Static inline int pipex_ppp_proto (struct mbuf *, struct pipex_session *, int, int *);
Static void pipex_ppp_input (struct mbuf *, struct pipex_session *, int);
Static void pipex_ip_input (struct mbuf *, struct pipex_session *);
#ifdef INET6
Static void pipex_ip6_input (struct mbuf *, struct pipex_session *);
#endif
Static struct mbuf *pipex_common_input(struct pipex_session *, struct mbuf *, int, int);
#ifdef PIPEX_PPPOE
Static void pipex_pppoe_output (struct mbuf *, struct pipex_session *);
#endif
#ifdef PIPEX_PPTP
Static void pipex_pptp_output (struct mbuf *, struct pipex_session *, int, int);
Static struct pipex_session *pipex_pptp_userland_lookup_session(struct mbuf *, struct sockaddr *);
#endif
#ifdef PIPEX_L2TP
Static void pipex_l2tp_output (struct mbuf *, struct pipex_session *);
#endif
#ifdef PIPEX_MPPE
Static void pipex_mppe_init (struct pipex_mppe *, int, int, u_char *, int);
Static void GetNewKeyFromSHA (u_char *, u_char *, int, u_char *);
Static void pipex_mppe_reduce_key (struct pipex_mppe *);
Static void mppe_key_change (struct pipex_mppe *);
Static void pipex_mppe_input (struct mbuf *, struct pipex_session *);
Static void pipex_mppe_output (struct mbuf *, struct pipex_session *, uint16_t);
Static void pipex_ccp_input (struct mbuf *, struct pipex_session *);
Static int pipex_ccp_output (struct pipex_session *, int, int);
Static inline int pipex_mppe_setkey(struct pipex_mppe *);
Static inline int pipex_mppe_setoldkey(struct pipex_mppe *, uint16_t);
Static inline void pipex_mppe_crypt(struct pipex_mppe *, int, u_char *, u_char *);
#endif
Static struct mbuf *adjust_tcp_mss (struct mbuf *, int);
Static struct mbuf *ip_is_idle_packet (struct mbuf *, int *);
Static void pipex_session_log (struct pipex_session *, int, const char *, ...) __attribute__((__format__(__printf__,3,4)));
Static uint32_t pipex_sockaddr_hash_key(struct sockaddr *);
Static int pipex_sockaddr_compar_addr(struct sockaddr *, struct sockaddr *);
Static int pipex_ppp_enqueue (struct mbuf *, struct pipex_session *, struct mbuf_queue *);
Static void pipex_ppp_dequeue (void);
Static void pipex_timer_start (void);
Static void pipex_timer_stop (void);
Static void pipex_timer (void *);
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