/* $OpenBSD: pipex.c,v 1.90 2016/11/18 02:53:47 dlg 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pf.h" #if NPF > 0 #include #endif #include "bpfilter.h" #if NBPFILTER > 0 #include #endif #include #include #ifdef INET6 #include #include #endif #include #include #include #include /* drop static for ddb debuggability */ #define Static #include #include "pipex_local.h" struct pool pipex_session_pool; struct pool mppe_key_pool; /* * static/global variables */ int pipex_enable = 0; struct pipex_hash_head pipex_session_list, /* master session list */ pipex_close_wait_list, /* expired session list */ pipex_peer_addr_hashtable[PIPEX_HASH_SIZE], /* peer's address hash */ pipex_id_hashtable[PIPEX_HASH_SIZE]; /* peer id hash */ struct radix_node_head pipex_rd_head4; struct radix_node_head pipex_rd_head6; int pipex_rd_head4_initialized; int pipex_rd_head6_initialized; struct timeout pipex_timer_ch; /* callout timer context */ int pipex_prune = 1; /* walk list every seconds */ /* pipex traffic queue */ struct mbuf_queue pipexinq = MBUF_QUEUE_INITIALIZER(IFQ_MAXLEN, IPL_NET); struct mbuf_queue pipexoutq = MBUF_QUEUE_INITIALIZER(IFQ_MAXLEN, IPL_NET); void *pipex_softintr = NULL; Static void pipex_softintr_handler(void *); /* borrow an mbuf pkthdr field */ #define ph_ppp_proto ether_vtag /* from udp_usrreq.c */ extern int udpcksum; #ifdef PIPEX_DEBUG int pipex_debug = 0; /* systcl net.inet.ip.pipex_debug */ #endif /* PPP compression == MPPE is assumed, so don't answer CCP Reset-Request. */ #define PIPEX_NO_CCP_RESETACK 1 /************************************************************************ * Core functions ************************************************************************/ void pipex_init(void) { int i; if (pipex_softintr != NULL) return; rn_init(sizeof(struct sockaddr_in6)); pool_init(&pipex_session_pool, sizeof(struct pipex_session), 0, IPL_NONE, PR_WAITOK, "ppxss", NULL); pool_init(&mppe_key_pool, PIPEX_MPPE_KEYLEN * PIPEX_MPPE_NOLDKEY, 0, IPL_NONE, PR_WAITOK, "mppekey", NULL); LIST_INIT(&pipex_session_list); LIST_INIT(&pipex_close_wait_list); for (i = 0; i < nitems(pipex_id_hashtable); i++) LIST_INIT(&pipex_id_hashtable[i]); for (i = 0; i < nitems(pipex_peer_addr_hashtable); i++) LIST_INIT(&pipex_peer_addr_hashtable[i]); /* softintr init */ pipex_softintr = softintr_establish(IPL_SOFTNET, pipex_softintr_handler, NULL); } void pipex_iface_init(struct pipex_iface_context *pipex_iface, struct ifnet *ifp) { int s; struct pipex_session *session; pipex_iface->pipexmode = 0; pipex_iface->ifnet_this = ifp; s = splnet(); if (!pipex_rd_head4_initialized) { pipex_rd_head4_initialized++; if (!rn_inithead0(&pipex_rd_head4, offsetof(struct sockaddr_in, sin_addr))) panic("rn_inithead0() failed on pipex_init()"); } if (!pipex_rd_head6_initialized) { pipex_rd_head6_initialized++; if (!rn_inithead0(&pipex_rd_head6, offsetof(struct sockaddr_in6, sin6_addr))) panic("rn_inithead0() failed on pipex_init()"); } splx(s); /* virtual pipex_session entry for multicast */ session = pool_get(&pipex_session_pool, PR_WAITOK | PR_ZERO); session->is_multicast = 1; session->pipex_iface = pipex_iface; pipex_iface->multicast_session = session; } Static void pipex_iface_start(struct pipex_iface_context *pipex_iface) { pipex_iface->pipexmode = 1; } Static void pipex_iface_stop(struct pipex_iface_context *pipex_iface) { struct pipex_session *session; struct pipex_session *session_next; pipex_iface->pipexmode = 0; /* * traversal all pipex sessions. * it will become heavy if the number of pppac devices bocomes large. */ for (session = LIST_FIRST(&pipex_session_list); session; session = session_next) { session_next = LIST_NEXT(session, session_list); if (session->pipex_iface == pipex_iface) pipex_destroy_session(session); } } void pipex_iface_fini(struct pipex_iface_context *pipex_iface) { int s; s = splnet(); pool_put(&pipex_session_pool, pipex_iface->multicast_session); pipex_iface_stop(pipex_iface); splx(s); } /* called from tunioctl() with splnet() */ int pipex_ioctl(struct pipex_iface_context *pipex_iface, u_long cmd, caddr_t data) { int pipexmode, ret; switch (cmd) { case PIPEXSMODE: pipexmode = *(int *)data; if (pipex_iface->pipexmode != pipexmode) { if (pipexmode) pipex_iface_start(pipex_iface); else pipex_iface_stop(pipex_iface); } break; case PIPEXGMODE: *(int *)data = pipex_iface->pipexmode; break; case PIPEXASESSION: ret = pipex_add_session((struct pipex_session_req *)data, pipex_iface); return (ret); case PIPEXDSESSION: ret = pipex_close_session( (struct pipex_session_close_req *)data); return (ret); case PIPEXCSESSION: ret = pipex_config_session( (struct pipex_session_config_req *)data); return (ret); case PIPEXGSTAT: ret = pipex_get_stat((struct pipex_session_stat_req *)data); return (ret); case PIPEXGCLOSED: ret = pipex_get_closed((struct pipex_session_list_req *)data); return (ret); default: return (ENOTTY); } return (0); } /************************************************************************ * Session management functions ************************************************************************/ Static int pipex_add_session(struct pipex_session_req *req, struct pipex_iface_context *iface) { struct pipex_session *session; struct pipex_hash_head *chain; struct radix_node *rn; int s; #ifdef PIPEX_PPPOE struct ifnet *over_ifp = NULL; #endif /* Checks requeted parameters. */ if (!iface->pipexmode) return (ENXIO); switch (req->pr_protocol) { #ifdef PIPEX_PPPOE case PIPEX_PROTO_PPPOE: over_ifp = ifunit(req->pr_proto.pppoe.over_ifname); if (over_ifp == NULL) return (EINVAL); if (req->pr_peer_address.ss_family != AF_UNSPEC) return (EINVAL); break; #endif #if defined(PIPEX_L2TP) || defined(PIPEX_PPTP) #ifdef PIPEX_PPTP case PIPEX_PROTO_PPTP: #endif #ifdef PIPEX_L2TP case PIPEX_PROTO_L2TP: #endif switch (req->pr_peer_address.ss_family) { case AF_INET: if (req->pr_peer_address.ss_len != sizeof(struct sockaddr_in)) return (EINVAL); break; #ifdef INET6 case AF_INET6: if (req->pr_peer_address.ss_len != sizeof(struct sockaddr_in6)) return (EINVAL); break; #endif default: return (EPROTONOSUPPORT); } if (req->pr_peer_address.ss_family != req->pr_local_address.ss_family || req->pr_peer_address.ss_len != req->pr_local_address.ss_len) return (EINVAL); break; #endif default: return (EPROTONOSUPPORT); } /* prepare a new session */ session = pool_get(&pipex_session_pool, PR_WAITOK | PR_ZERO); session->state = PIPEX_STATE_OPENED; session->protocol = req->pr_protocol; session->session_id = req->pr_session_id; session->peer_session_id = req->pr_peer_session_id; session->peer_mru = req->pr_peer_mru; session->timeout_sec = req->pr_timeout_sec; session->pipex_iface = iface; session->ppp_flags = req->pr_ppp_flags; session->ppp_id = req->pr_ppp_id; session->ip_forward = 1; session->ip_address.sin_family = AF_INET; session->ip_address.sin_len = sizeof(struct sockaddr_in); session->ip_address.sin_addr = req->pr_ip_address; session->ip_netmask.sin_family = AF_INET; session->ip_netmask.sin_len = sizeof(struct sockaddr_in); session->ip_netmask.sin_addr = req->pr_ip_netmask; if (session->ip_netmask.sin_addr.s_addr == 0L) session->ip_netmask.sin_addr.s_addr = 0xffffffffL; session->ip_address.sin_addr.s_addr &= session->ip_netmask.sin_addr.s_addr; if (req->pr_peer_address.ss_len > 0) memcpy(&session->peer, &req->pr_peer_address, MIN(req->pr_peer_address.ss_len, sizeof(session->peer))); if (req->pr_local_address.ss_len > 0) memcpy(&session->local, &req->pr_local_address, MIN(req->pr_local_address.ss_len, sizeof(session->local))); #ifdef PIPEX_PPPOE if (req->pr_protocol == PIPEX_PROTO_PPPOE) session->proto.pppoe.over_ifp = over_ifp; #endif #ifdef PIPEX_PPTP if (req->pr_protocol == PIPEX_PROTO_PPTP) { struct pipex_pptp_session *sess_pptp = &session->proto.pptp; sess_pptp->snd_gap = 0; sess_pptp->rcv_gap = 0; sess_pptp->snd_una = req->pr_proto.pptp.snd_una; sess_pptp->snd_nxt = req->pr_proto.pptp.snd_nxt; sess_pptp->rcv_nxt = req->pr_proto.pptp.rcv_nxt; sess_pptp->rcv_acked = req->pr_proto.pptp.rcv_acked; sess_pptp->winsz = req->pr_proto.pptp.winsz; sess_pptp->maxwinsz = req->pr_proto.pptp.maxwinsz; sess_pptp->peer_maxwinsz = req->pr_proto.pptp.peer_maxwinsz; /* last ack number */ sess_pptp->ul_snd_una = sess_pptp->snd_una - 1; } #endif #ifdef PIPEX_L2TP if (req->pr_protocol == PIPEX_PROTO_L2TP) { struct pipex_l2tp_session *sess_l2tp = &session->proto.l2tp; /* session keys */ sess_l2tp->tunnel_id = req->pr_proto.l2tp.tunnel_id; sess_l2tp->peer_tunnel_id = req->pr_proto.l2tp.peer_tunnel_id; /* protocol options */ sess_l2tp->option_flags = req->pr_proto.l2tp.option_flags; /* initial state of dynamic context */ sess_l2tp->ns_gap = sess_l2tp->nr_gap = 0; sess_l2tp->ns_nxt = req->pr_proto.l2tp.ns_nxt; sess_l2tp->nr_nxt = req->pr_proto.l2tp.nr_nxt; sess_l2tp->ns_una = req->pr_proto.l2tp.ns_una; sess_l2tp->nr_acked = req->pr_proto.l2tp.nr_acked; /* last ack number */ sess_l2tp->ul_ns_una = sess_l2tp->ns_una - 1; sess_l2tp->ipsecflowinfo = req->pr_proto.l2tp.ipsecflowinfo; } #endif #ifdef PIPEX_MPPE if ((req->pr_ppp_flags & PIPEX_PPP_MPPE_ACCEPTED) != 0) { if (req->pr_mppe_recv.keylenbits <= 0) { pool_put(&pipex_session_pool, session); return (EINVAL); } pipex_session_init_mppe_recv(session, req->pr_mppe_recv.stateless, req->pr_mppe_recv.keylenbits, req->pr_mppe_recv.master_key); } if ((req->pr_ppp_flags & PIPEX_PPP_MPPE_ENABLED) != 0) { if (req->pr_mppe_send.keylenbits <= 0) { pool_put(&pipex_session_pool, session); return (EINVAL); } pipex_session_init_mppe_send(session, req->pr_mppe_send.stateless, req->pr_mppe_send.keylenbits, req->pr_mppe_send.master_key); } if (pipex_session_is_mppe_required(session)) { if (!pipex_session_is_mppe_enabled(session) || !pipex_session_is_mppe_accepted(session)) { pool_put(&pipex_session_pool, session); return (EINVAL); } } #endif /* commit the session */ s = splnet(); if (!in_nullhost(session->ip_address.sin_addr)) { if (pipex_lookup_by_ip_address(session->ip_address.sin_addr) != NULL) { splx(s); pool_put(&pipex_session_pool, session); return (EADDRINUSE); } rn = rn_addroute(&session->ip_address, &session->ip_netmask, &pipex_rd_head4, session->ps4_rn, RTP_STATIC); if (rn == NULL) { splx(s); pool_put(&pipex_session_pool, session); return (ENOMEM); } } if (0) { /* NOT YET */ rn = rn_addroute(&session->ip6_address, &session->ip6_prefixlen, &pipex_rd_head6, session->ps6_rn, RTP_STATIC); if (rn == NULL) { splx(s); pool_put(&pipex_session_pool, session); return (ENOMEM); } } chain = PIPEX_ID_HASHTABLE(session->session_id); LIST_INSERT_HEAD(chain, session, id_chain); LIST_INSERT_HEAD(&pipex_session_list, session, session_list); switch (req->pr_protocol) { case PIPEX_PROTO_PPTP: case PIPEX_PROTO_L2TP: chain = PIPEX_PEER_ADDR_HASHTABLE( pipex_sockaddr_hash_key((struct sockaddr *)&session->peer)); LIST_INSERT_HEAD(chain, session, peer_addr_chain); } /* if first session is added, start timer */ if (LIST_NEXT(session, session_list) == NULL) pipex_timer_start(); splx(s); pipex_session_log(session, LOG_INFO, "PIPEX is ready."); return (0); } int pipex_notify_close_session(struct pipex_session *session) { int s; s = splnet(); session->state = PIPEX_STATE_CLOSE_WAIT; session->stat.idle_time = 0; LIST_INSERT_HEAD(&pipex_close_wait_list, session, state_list); splx(s); return (0); } int pipex_notify_close_session_all(void) { struct pipex_session *session; int s; s = splnet(); LIST_FOREACH(session, &pipex_session_list, session_list) if (session->state == PIPEX_STATE_OPENED) pipex_notify_close_session(session); splx(s); return (0); } Static int pipex_close_session(struct pipex_session_close_req *req) { struct pipex_session *session; int s; s = splnet(); session = pipex_lookup_by_session_id(req->pcr_protocol, req->pcr_session_id); if (session == NULL) { splx(s); return (EINVAL); } /* remove from close_wait list */ if (session->state == PIPEX_STATE_CLOSE_WAIT) LIST_REMOVE(session, state_list); /* get statistics before destroy the session */ req->pcr_stat = session->stat; session->state = PIPEX_STATE_CLOSED; splx(s); return (0); } Static int pipex_config_session(struct pipex_session_config_req *req) { struct pipex_session *session; int s; s = splnet(); session = pipex_lookup_by_session_id(req->pcr_protocol, req->pcr_session_id); if (session == NULL) { splx(s); return (EINVAL); } session->ip_forward = req->pcr_ip_forward; splx(s); return (0); } Static int pipex_get_stat(struct pipex_session_stat_req *req) { struct pipex_session *session; int s; s = splnet(); session = pipex_lookup_by_session_id(req->psr_protocol, req->psr_session_id); if (session == NULL) { splx(s); return (EINVAL); } req->psr_stat = session->stat; splx(s); return (0); } Static int pipex_get_closed(struct pipex_session_list_req *req) { struct pipex_session *session; int s; s = splnet(); bzero(req, sizeof(*req)); while (!LIST_EMPTY(&pipex_close_wait_list)) { session = LIST_FIRST(&pipex_close_wait_list); req->plr_ppp_id[req->plr_ppp_id_count++] = session->ppp_id; LIST_REMOVE(session, state_list); session->state = PIPEX_STATE_CLOSE_WAIT2; if (req->plr_ppp_id_count >= PIPEX_MAX_LISTREQ) { if (!LIST_EMPTY(&pipex_close_wait_list)) req->plr_flags |= PIPEX_LISTREQ_MORE; break; } } splx(s); return (0); } Static int pipex_destroy_session(struct pipex_session *session) { struct radix_node *rn; int s; /* remove from radix tree and hash chain */ s = splnet(); if (!in_nullhost(session->ip_address.sin_addr)) { rn = rn_delete(&session->ip_address, &session->ip_netmask, &pipex_rd_head4, (struct radix_node *)session); KASSERT(rn != NULL); } LIST_REMOVE(session, id_chain); LIST_REMOVE(session, session_list); #ifdef PIPEX_PPTP if (session->protocol == PIPEX_PROTO_PPTP) { LIST_REMOVE(session, peer_addr_chain); } #endif #ifdef PIPEX_L2TP if (session->protocol == PIPEX_PROTO_L2TP) { LIST_REMOVE(session, peer_addr_chain); } #endif /* if final session is destroyed, stop timer */ if (LIST_EMPTY(&pipex_session_list)) pipex_timer_stop(); splx(s); if (session->mppe_recv.old_session_keys) pool_put(&mppe_key_pool, session->mppe_recv.old_session_keys); pool_put(&pipex_session_pool, session); return (0); } Static struct pipex_session * pipex_lookup_by_ip_address(struct in_addr addr) { struct pipex_session *session; struct sockaddr_in pipex_in4, pipex_in4mask; bzero(&pipex_in4, sizeof(pipex_in4)); pipex_in4.sin_addr = addr; pipex_in4.sin_family = AF_INET; pipex_in4.sin_len = sizeof(pipex_in4); bzero(&pipex_in4mask, sizeof(pipex_in4mask)); pipex_in4mask.sin_addr.s_addr = htonl(0xFFFFFFFFL); pipex_in4mask.sin_family = AF_INET; pipex_in4mask.sin_len = sizeof(pipex_in4mask); session = (struct pipex_session *)rn_lookup(&pipex_in4, &pipex_in4mask, &pipex_rd_head4); #ifdef PIPEX_DEBUG if (session == NULL) { char buf[INET_ADDRSTRLEN]; PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (addr=%s)", __func__, inet_ntop(AF_INET, &addr, buf, sizeof(buf)))); } #endif return (session); } Static struct pipex_session * pipex_lookup_by_session_id(int protocol, int session_id) { struct pipex_hash_head *list; struct pipex_session *session; list = PIPEX_ID_HASHTABLE(session_id); LIST_FOREACH(session, list, id_chain) { if (session->protocol == protocol && session->session_id == session_id) break; } #ifdef PIPEX_DEBUG if (session == NULL) PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (session_id=%d)", __func__, session_id)); #endif return (session); } /*********************************************************************** * Queue and Software Interrupt Handler ***********************************************************************/ Static void pipex_softintr_handler(void *dummy) { /* called at splsoftnet() */ pipex_ppp_dequeue(); } Static void pipex_ppp_dequeue(void) { struct pipex_session *pkt_session; u_int16_t proto; struct mbuf *m; struct mbuf_list ml; /* ppp output */ mq_delist(&pipexoutq, &ml); while ((m = ml_dequeue(&ml)) != NULL) { pkt_session = m->m_pkthdr.ph_cookie; if (pkt_session == NULL) { m_freem(m); continue; } proto = m->m_pkthdr.ph_ppp_proto; m->m_pkthdr.ph_cookie = NULL; m->m_pkthdr.ph_ppp_proto = 0; if (pkt_session->is_multicast != 0) { struct pipex_session *session; struct mbuf *m0; LIST_FOREACH(session, &pipex_session_list, session_list) { if (session->pipex_iface != pkt_session->pipex_iface) continue; if (session->ip_forward == 0 && session->ip6_forward == 0) continue; m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) { session->stat.oerrors++; continue; } pipex_ppp_output(m0, session, proto); } m_freem(m); } else pipex_ppp_output(m, pkt_session, proto); } /* ppp input */ mq_delist(&pipexinq, &ml); while ((m = ml_dequeue(&ml)) != NULL) { pkt_session = m->m_pkthdr.ph_cookie; if (pkt_session == NULL) { m_freem(m); continue; } pipex_ppp_input(m, pkt_session, 0); } } Static int pipex_ppp_enqueue(struct mbuf *m0, struct pipex_session *session, struct mbuf_queue *mq) { m0->m_pkthdr.ph_cookie = session; /* XXX need to support other protocols */ m0->m_pkthdr.ph_ppp_proto = PPP_IP; if (mq_enqueue(mq, m0) != 0) return (1); softintr_schedule(pipex_softintr); return (0); } /*********************************************************************** * Timer functions ***********************************************************************/ Static void pipex_timer_start(void) { timeout_set(&pipex_timer_ch, pipex_timer, NULL); timeout_add_sec(&pipex_timer_ch, pipex_prune); } Static void pipex_timer_stop(void) { timeout_del(&pipex_timer_ch); } Static void pipex_timer(void *ignored_arg) { int s; struct pipex_session *session; struct pipex_session *session_next; s = splnet(); timeout_add_sec(&pipex_timer_ch, pipex_prune); /* walk through */ for (session = LIST_FIRST(&pipex_session_list); session; session = session_next) { session_next = LIST_NEXT(session, session_list); switch (session->state) { case PIPEX_STATE_OPENED: if (session->timeout_sec == 0) continue; session->stat.idle_time++; if (session->stat.idle_time < session->timeout_sec) continue; pipex_notify_close_session(session); break; case PIPEX_STATE_CLOSE_WAIT: case PIPEX_STATE_CLOSE_WAIT2: /* Wait PIPEXDSESSION from userland */ session->stat.idle_time++; if (session->stat.idle_time < PIPEX_CLOSE_TIMEOUT) continue; if (session->state == PIPEX_STATE_CLOSE_WAIT) LIST_REMOVE(session, state_list); session->state = PIPEX_STATE_CLOSED; /* FALLTHROUGH */ case PIPEX_STATE_CLOSED: /* * mbuf queued in pipexinq or pipexoutq may have a * refererce to this session. */ if (!mq_empty(&pipexinq) || !mq_empty(&pipexoutq)) continue; pipex_destroy_session(session); break; default: break; } } splx(s); } /*********************************************************************** * Common network I/O functions. (tunnel protocol independent) ***********************************************************************/ struct mbuf * pipex_output(struct mbuf *m0, int af, int off, struct pipex_iface_context *pipex_iface) { struct pipex_session *session; struct ip ip; struct mbuf *mret; session = NULL; mret = NULL; switch (af) { case AF_INET: if (m0->m_pkthdr.len >= sizeof(struct ip) + off) { m_copydata(m0, off, sizeof(struct ip), (caddr_t)&ip); if (IN_MULTICAST(ip.ip_dst.s_addr)) session = pipex_iface->multicast_session; else session = pipex_lookup_by_ip_address(ip.ip_dst); } if (session != NULL) { if (session == pipex_iface->multicast_session) { mret = m0; m0 = m_copym(m0, 0, M_COPYALL, M_NOWAIT); if (m0 == NULL) { m0 = mret; mret = NULL; goto drop; } } if (off > 0) m_adj(m0, off); pipex_ip_output(m0, session); return (mret); } break; } return (m0); drop: m_freem(m0); if (session != NULL) session->stat.oerrors++; return(NULL); } Static void pipex_ip_output(struct mbuf *m0, struct pipex_session *session) { int is_idle; struct ifnet *ifp; /* output succeed here as a interface */ ifp = session->pipex_iface->ifnet_this; ifp->if_opackets++; ifp->if_obytes+=m0->m_pkthdr.len; if (session->is_multicast == 0) { /* * Multicast packet is a idle packet and it's not TCP. */ if (session->ip_forward == 0 && session->ip6_forward == 0) goto drop; /* reset idle timer */ if (session->timeout_sec != 0) { is_idle = 0; m0 = ip_is_idle_packet(m0, &is_idle); if (m0 == NULL) goto dropped; if (is_idle == 0) /* update expire time */ session->stat.idle_time = 0; } /* adjust tcpmss */ if ((session->ppp_flags & PIPEX_PPP_ADJUST_TCPMSS) != 0) { m0 = adjust_tcp_mss(m0, session->peer_mru); if (m0 == NULL) goto dropped; } } else m0->m_flags &= ~(M_BCAST|M_MCAST); /* output ip packets to the session tunnel */ if (pipex_ppp_enqueue(m0, session, &pipexoutq)) goto dropped; return; drop: m_freem(m0); dropped: session->stat.oerrors++; } Static void pipex_ppp_output(struct mbuf *m0, struct pipex_session *session, int proto) { u_char *cp, hdr[16]; #ifdef PIPEX_MPPE if (pipex_session_is_mppe_enabled(session)) { if (proto == PPP_IP) { pipex_mppe_output(m0, session, PPP_IP); return; } } #endif /* PIPEX_MPPE */ cp = hdr; if (session->protocol != PIPEX_PROTO_PPPOE) { /* PPPoE has not address and control field */ PUTCHAR(PPP_ALLSTATIONS, cp); PUTCHAR(PPP_UI, cp); } PUTSHORT(proto, cp); M_PREPEND(m0, cp - hdr, M_NOWAIT); if (m0 == NULL) goto drop; memcpy(mtod(m0, u_char *), hdr, cp - hdr); switch (session->protocol) { #ifdef PIPEX_PPPOE case PIPEX_PROTO_PPPOE: pipex_pppoe_output(m0, session); break; #endif #ifdef PIPEX_PPTP case PIPEX_PROTO_PPTP: pipex_pptp_output(m0, session, 1, 1); break; #endif #ifdef PIPEX_L2TP case PIPEX_PROTO_L2TP: pipex_l2tp_output(m0, session); break; #endif default: goto drop; } return; drop: m_freem(m0); session->stat.oerrors++; } Static void pipex_ppp_input(struct mbuf *m0, struct pipex_session *session, int decrypted) { int proto, hlen = 0; KASSERT(m0->m_pkthdr.len >= PIPEX_PPPMINLEN); proto = pipex_ppp_proto(m0, session, 0, &hlen); #ifdef PIPEX_MPPE if (proto == PPP_COMP) { if (decrypted) goto drop; /* checked this on ppp_common_input() already. */ KASSERT(pipex_session_is_mppe_accepted(session)); m_adj(m0, hlen); pipex_mppe_input(m0, session); return; } if (proto == PPP_CCP) { if (decrypted) goto drop; #if NBPFILTER > 0 { struct ifnet *ifp = session->pipex_iface->ifnet_this; if (ifp->if_bpf && ifp->if_type == IFT_PPP) bpf_mtap(ifp->if_bpf, m0, BPF_DIRECTION_IN); } #endif m_adj(m0, hlen); pipex_ccp_input(m0, session); return; } #endif switch (proto) { case PPP_IP: if (session->ip_forward == 0) goto drop; if (!decrypted && pipex_session_is_mppe_required(session)) /* * if ip packet received when mppe * is required, discard it. */ goto drop; m_adj(m0, hlen); pipex_ip_input(m0, session); return; #ifdef INET6 case PPP_IPV6: if (session->ip6_forward == 0) goto drop; if (!decrypted && pipex_session_is_mppe_required(session)) /* * if ip packet received when mppe * is required, discard it. */ goto drop; m_adj(m0, hlen); pipex_ip6_input(m0, session); return; #endif default: if (decrypted) goto drop; /* protocol must be checked on pipex_common_input() already */ KASSERT(0); goto drop; } return; drop: m_freem(m0); session->stat.ierrors++; } Static void pipex_ip_input(struct mbuf *m0, struct pipex_session *session) { struct ifnet *ifp; struct ip *ip; int len; int is_idle; /* change recvif */ ifp = session->pipex_iface->ifnet_this; m0->m_pkthdr.ph_ifidx = ifp->if_index; PIPEX_PULLUP(m0, sizeof(struct ip)); if (m0 == NULL) goto drop; #if 0 /* * XXX: hsuenaga * we need to know openbsd manners to adjust alignment */ if (!ALIGNED_POINTER(mtod(m0, caddr_t), struct ip *)) { /* ip_output() assumes ip packet is aligned. */ if ((m0 = m_copyup(m0, sizeof(struct ip), ((max_linkhdr + 3) & ~3))) == NULL) goto drop; } #endif if (ISSET(session->ppp_flags, PIPEX_PPP_INGRESS_FILTER)) { /* ingress filter */ ip = mtod(m0, struct ip *); if ((ip->ip_src.s_addr & session->ip_netmask.sin_addr.s_addr) != session->ip_address.sin_addr.s_addr) { char src[INET_ADDRSTRLEN]; pipex_session_log(session, LOG_DEBUG, "ip packet discarded by ingress filter (src %s)", inet_ntop(AF_INET, &ip->ip_src, src, sizeof(src))); goto drop; } } /* idle timer */ if (session->timeout_sec != 0) { is_idle = 0; m0 = ip_is_idle_packet(m0, &is_idle); if (m0 == NULL) goto drop; if (is_idle == 0) /* update expire time */ session->stat.idle_time = 0; } /* adjust tcpmss */ if (session->ppp_flags & PIPEX_PPP_ADJUST_TCPMSS) { m0 = adjust_tcp_mss(m0, session->peer_mru); if (m0 == NULL) goto drop; } #if NPF > 0 pf_pkt_addr_changed(m0); #endif len = m0->m_pkthdr.len; #if NBPFILTER > 0 if (ifp->if_bpf) bpf_mtap_af(ifp->if_bpf, AF_INET, m0, BPF_DIRECTION_IN); #endif if (niq_enqueue(&ipintrq, m0) != 0) { ifp->if_collisions++; goto dropped; } ifp->if_ipackets++; ifp->if_ibytes += len; session->stat.ipackets++; session->stat.ibytes += len; return; drop: m_freem(m0); dropped: session->stat.ierrors++; } #ifdef INET6 Static void pipex_ip6_input(struct mbuf *m0, struct pipex_session *session) { struct ifnet *ifp; int len; /* change recvif */ ifp = session->pipex_iface->ifnet_this; m0->m_pkthdr.ph_ifidx = ifp->if_index; #if 0 /* XXX: alignment */ PIPEX_PULLUP(m0, sizeof(struct ip6_hdr)); if (m0 == NULL) goto drop; if (!ALIGNED_POINTER(mtod(m0, caddr_t), struct ip6_hdr *)) { /* ip6_output() assumes ip packet is aligned. */ if ((m0 = m_copyup(m0, sizeof(struct ip6_hdr), ((max_linkhdr + 3) & ~3))) == NULL) goto drop; } #endif /* * XXX: what is reasonable ingress filter ??? * only one address is enough ?? */ /* XXX: we must define idle packet for IPv6(ICMPv6). */ /* * XXX: tcpmss adjustment for IPv6 is required??? * We may use PMTUD in IPv6.... */ #if NPF > 0 pf_pkt_addr_changed(m0); #endif len = m0->m_pkthdr.len; #if NBPFILTER > 0 if (ifp->if_bpf) bpf_mtap_af(ifp->if_bpf, AF_INET6, m0, BPF_DIRECTION_IN); #endif if (niq_enqueue(&ip6intrq, m0) != 0) { ifp->if_collisions++; goto dropped; } ifp->if_ipackets++; ifp->if_ibytes += len; session->stat.ipackets++; session->stat.ibytes += len; return; dropped: session->stat.ierrors++; } #endif Static struct mbuf * pipex_common_input(struct pipex_session *session, struct mbuf *m0, int hlen, int plen) { int proto, ppphlen; u_char code; if ((m0->m_pkthdr.len < hlen + PIPEX_PPPMINLEN) || (plen < PIPEX_PPPMINLEN)) goto drop; proto = pipex_ppp_proto(m0, session, hlen, &ppphlen); switch (proto) { #ifdef PIPEX_MPPE case PPP_CCP: code = 0; KASSERT(m0->m_pkthdr.len >= hlen + ppphlen + 1); m_copydata(m0, hlen + ppphlen, 1, (caddr_t)&code); if (code != CCP_RESETREQ && code != CCP_RESETACK) goto not_ours; break; case PPP_COMP: if (pipex_session_is_mppe_accepted(session)) break; goto not_ours; #endif case PPP_IP: #ifdef INET6 case PPP_IPV6: #endif break; default: goto not_ours; } /* ok, The packet is for PIPEX */ m_adj(m0, hlen);/* cut off the tunnle protocol header */ /* ensure the mbuf length equals the PPP frame length */ if (m0->m_pkthdr.len < plen) goto drop; if (m0->m_pkthdr.len > plen) { if (m0->m_len == m0->m_pkthdr.len) { m0->m_len = plen; m0->m_pkthdr.len = plen; } else m_adj(m0, plen - m0->m_pkthdr.len); } /* input ppp packets to kernel session */ if (pipex_ppp_enqueue(m0, session, &pipexinq) != 0) goto dropped; else return (NULL); drop: m_freem(m0); dropped: session->stat.ierrors++; return (NULL); not_ours: return (m0); /* Not to be handled by PIPEX */ } /* * pipex_ppp_proto */ Static int pipex_ppp_proto(struct mbuf *m0, struct pipex_session *session, int off, int *hlenp) { int proto; u_char *cp, pktbuf[4]; KASSERT(m0->m_pkthdr.len > sizeof(pktbuf)); m_copydata(m0, off, sizeof(pktbuf), pktbuf); cp = pktbuf; if (pipex_session_has_acf(session)) { if (cp[0] == PPP_ALLSTATIONS && cp[1] == PPP_UI) cp += 2; #ifdef PIPEX_DEBUG else if (!pipex_session_is_acfc_accepted(session)) PIPEX_DBG((session, LOG_DEBUG, "no acf but acfc is not accepted by the peer.")); #endif } if ((*cp & 0x01) != 0) { if (!pipex_session_is_pfc_accepted(session)) { PIPEX_DBG((session, LOG_DEBUG, "Received a broken ppp " "frame. No protocol field. %02x-%02x", cp[0], cp[1])); return (-1); } GETCHAR(proto, cp); } else GETSHORT(proto, cp); if (hlenp != NULL) *hlenp = cp - pktbuf; return (proto); } #ifdef PIPEX_PPPOE /*********************************************************************** * PPPoE ***********************************************************************/ Static u_char pipex_pppoe_padding[ETHERMIN]; /* * pipex_pppoe_lookup_session */ struct pipex_session * pipex_pppoe_lookup_session(struct mbuf *m0) { struct pipex_session *session; struct pipex_pppoe_header pppoe; /* short packet */ if (m0->m_pkthdr.len < (sizeof(struct ether_header) + sizeof(pppoe))) return (NULL); m_copydata(m0, sizeof(struct ether_header), sizeof(struct pipex_pppoe_header), (caddr_t)&pppoe); pppoe.session_id = ntohs(pppoe.session_id); session = pipex_lookup_by_session_id(PIPEX_PROTO_PPPOE, pppoe.session_id); #ifdef PIPEX_DEBUG if (session == NULL) PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (id=%d)", __func__, pppoe.session_id)); #endif return (session); } struct mbuf * pipex_pppoe_input(struct mbuf *m0, struct pipex_session *session) { int hlen; struct pipex_pppoe_header pppoe; /* already checked at pipex_pppoe_lookup_session */ KASSERT(m0->m_pkthdr.len >= (sizeof(struct ether_header) + sizeof(pppoe))); m_copydata(m0, sizeof(struct ether_header), sizeof(struct pipex_pppoe_header), (caddr_t)&pppoe); hlen = sizeof(struct ether_header) + sizeof(struct pipex_pppoe_header); if ((m0 = pipex_common_input(session, m0, hlen, ntohs(pppoe.length))) == NULL) return (NULL); m_freem(m0); session->stat.ierrors++; return (NULL); } /* * pipex_ppope_output */ Static void pipex_pppoe_output(struct mbuf *m0, struct pipex_session *session) { struct pipex_pppoe_header *pppoe; struct ifnet *ifp, *over_ifp; int len, padlen; /* save length for pppoe header */ len = m0->m_pkthdr.len; ifp = session->pipex_iface->ifnet_this; over_ifp = session->proto.pppoe.over_ifp; /* prepend protocol header */ M_PREPEND(m0, sizeof(struct pipex_pppoe_header), M_NOWAIT); if (m0 == NULL) { PIPEX_DBG((NULL, LOG_ERR, "<%s> cannot prepend header.", __func__)); session->stat.oerrors++; return; } padlen = ETHERMIN - m0->m_pkthdr.len; if (padlen > 0) m_copyback(m0, m0->m_pkthdr.len, padlen, pipex_pppoe_padding, M_NOWAIT); /* setup pppoe header information */ pppoe = mtod(m0, struct pipex_pppoe_header *); pppoe->vertype = PIPEX_PPPOE_VERTYPE; pppoe->code = PIPEX_PPPOE_CODE_SESSION; pppoe->session_id = htons(session->session_id); pppoe->length = htons(len); m0->m_pkthdr.ph_ifidx = ifp->if_index; m0->m_flags &= ~(M_BCAST|M_MCAST); session->stat.opackets++; session->stat.obytes += len; over_ifp->if_output(over_ifp, m0, (struct sockaddr *)&session->peer, NULL); } #endif /* PIPEX_PPPOE */ #ifdef PIPEX_PPTP /*********************************************************************** * PPTP ***********************************************************************/ Static void pipex_pptp_output(struct mbuf *m0, struct pipex_session *session, int has_seq, int has_ack) { int len, reqlen; struct pipex_gre_header *gre = NULL; struct ip *ip; u_char *cp; reqlen = PIPEX_IPGRE_HDRLEN + (has_seq + has_ack) * 4; len = 0; if (m0 != NULL) { /* save length for gre header */ len = m0->m_pkthdr.len; /* prepend protocol header */ M_PREPEND(m0, reqlen, M_NOWAIT); if (m0 == NULL) goto drop; } else { MGETHDR(m0, M_DONTWAIT, MT_DATA); if (m0 && reqlen > MHLEN) { MCLGET(m0, M_DONTWAIT); if ((m0->m_flags & M_EXT) == 0) { m_freem(m0); m0 = NULL; } } if (m0 == NULL) goto drop; m0->m_pkthdr.len = m0->m_len = reqlen; } /* setup ip header information */ ip = mtod(m0, struct ip *); ip->ip_len = htons(m0->m_pkthdr.len); ip->ip_off = 0; ip->ip_ttl = MAXTTL; ip->ip_p = IPPROTO_GRE; ip->ip_tos = 0; ip->ip_src = session->local.sin4.sin_addr; ip->ip_dst = session->peer.sin4.sin_addr; #if NPF > 0 pf_pkt_addr_changed(m0); #endif /* setup gre(ver1) header information */ gre = PIPEX_SEEK_NEXTHDR(ip, sizeof(struct ip), struct pipex_gre_header *); gre->type = htons(PIPEX_GRE_PROTO_PPP); gre->call_id = htons(session->peer_session_id); gre->flags = PIPEX_GRE_KFLAG | PIPEX_GRE_VER; /* do htons later */ gre->len = htons(len); cp = PIPEX_SEEK_NEXTHDR(gre, sizeof(struct pipex_gre_header),u_char *); if (has_seq) { gre->flags |= PIPEX_GRE_SFLAG; PUTLONG(session->proto.pptp.snd_nxt, cp); session->proto.pptp.snd_nxt++; session->proto.pptp.snd_gap++; } if (has_ack) { gre->flags |= PIPEX_GRE_AFLAG; session->proto.pptp.rcv_acked = session->proto.pptp.rcv_nxt - 1; PUTLONG(session->proto.pptp.rcv_acked, cp); } gre->flags = htons(gre->flags); m0->m_pkthdr.ph_ifidx = session->pipex_iface->ifnet_this->if_index; if (ip_output(m0, NULL, NULL, 0, NULL, NULL, 0) != 0) { PIPEX_DBG((session, LOG_DEBUG, "ip_output failed.")); goto drop; } if (len > 0) { /* network layer only */ /* countup statistics */ session->stat.opackets++; session->stat.obytes += len; } return; drop: session->stat.oerrors++; } struct pipex_session * pipex_pptp_lookup_session(struct mbuf *m0) { struct pipex_session *session; struct pipex_gre_header gre; struct ip ip; uint16_t flags; uint16_t id; int hlen; if (m0->m_pkthdr.len < PIPEX_IPGRE_HDRLEN) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> packet length is too short", __func__)); goto not_ours; } /* get ip header info */ m_copydata(m0, 0, sizeof(struct ip), (caddr_t)&ip); hlen = ip.ip_hl << 2; /* * m0 has already passed ip_input(), so there is * no necessity for ip packet inspection. */ /* get gre flags */ m_copydata(m0, hlen, sizeof(gre), (caddr_t)&gre); flags = ntohs(gre.flags); /* gre version must be '1' */ if ((flags & PIPEX_GRE_VERMASK) != PIPEX_GRE_VER) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> gre header wrong version.", __func__)); goto not_ours; } /* gre keys must be present */ if ((flags & PIPEX_GRE_KFLAG) == 0) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> gre header has no keys.", __func__)); goto not_ours; } /* flag check */ if ((flags & PIPEX_GRE_UNUSEDFLAGS) != 0) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> gre header has unused flags at pptp.", __func__)); goto not_ours; } /* lookup pipex session table */ id = ntohs(gre.call_id); session = pipex_lookup_by_session_id(PIPEX_PROTO_PPTP, id); #ifdef PIPEX_DEBUG if (session == NULL) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (id=%d)", __func__, id)); goto not_ours; } #endif return (session); not_ours: return (NULL); } struct mbuf * pipex_pptp_input(struct mbuf *m0, struct pipex_session *session) { int hlen, has_seq, has_ack, nseq; const char *reason = ""; u_char *cp, *seqp = NULL, *ackp = NULL; uint32_t flags, seq = 0, ack = 0; struct ip *ip; struct pipex_gre_header *gre; struct pipex_pptp_session *pptp_session; int rewind = 0; KASSERT(m0->m_pkthdr.len >= PIPEX_IPGRE_HDRLEN); pptp_session = &session->proto.pptp; /* get ip header */ ip = mtod(m0, struct ip *); hlen = ip->ip_hl << 2; /* seek gre header */ gre = PIPEX_SEEK_NEXTHDR(ip, hlen, struct pipex_gre_header *); flags = ntohs(gre->flags); /* pullup for seek sequences in header */ has_seq = (flags & PIPEX_GRE_SFLAG) ? 1 : 0; has_ack = (flags & PIPEX_GRE_AFLAG) ? 1 : 0; hlen = PIPEX_IPGRE_HDRLEN + 4 * (has_seq + has_ack); if (m0->m_len < hlen) { m0 = m_pullup(m0, hlen); if (m0 == NULL) { PIPEX_DBG((session, LOG_DEBUG, "pullup failed.")); goto drop; } } /* check sequence */ cp = PIPEX_SEEK_NEXTHDR(gre, sizeof(struct pipex_gre_header),u_char *); if (has_seq) { seqp = cp; GETLONG(seq, cp); } if (has_ack) { ackp = cp; GETLONG(ack, cp); if (ack + 1 == pptp_session->snd_una) { /* ack has not changed before */ } else if (SEQ32_LT(ack, pptp_session->snd_una)) { /* OoO ack packets should not be dropped. */ rewind = 1; } else if (SEQ32_GT(ack, pptp_session->snd_nxt)) { reason = "ack for unknown sequence"; goto out_seq; } else pptp_session->snd_una = ack + 1; } if (!has_seq) { /* ack only packet */ goto not_ours; } if (SEQ32_LT(seq, pptp_session->rcv_nxt)) { rewind = 1; if (SEQ32_LT(seq, pptp_session->rcv_nxt - PIPEX_REWIND_LIMIT)) { reason = "out of sequence"; goto out_seq; } } else if (SEQ32_GE(seq, pptp_session->rcv_nxt + pptp_session->maxwinsz)) { pipex_session_log(session, LOG_DEBUG, "received packet caused window overflow. seq=%u(%u-%u)" "may lost %d packets.", seq, pptp_session->rcv_nxt, pptp_session->rcv_nxt + pptp_session->maxwinsz, (int)SEQ32_SUB(seq, pptp_session->rcv_nxt)); } seq++; nseq = SEQ32_SUB(seq, pptp_session->rcv_nxt); if (!rewind) { pptp_session->rcv_nxt = seq; if (SEQ32_SUB(seq, pptp_session->rcv_acked) > roundup(pptp_session->winsz, 2) / 2) /* Send ack only packet. */ pipex_pptp_output(NULL, session, 0, 1); } if ((m0 = pipex_common_input(session, m0, hlen, (int)ntohs(gre->len))) == NULL) { /* ok, The packet is for PIPEX */ if (!rewind) session->proto.pptp.rcv_gap += nseq; return (NULL); } if (rewind) goto out_seq; not_ours: seq--; /* revert original seq value */ /* * overwrite sequence numbers to adjust a gap between pipex and * userland. */ if (seqp != NULL) { seq -= pptp_session->rcv_gap; PUTLONG(seq, seqp); } if (ackp != NULL) { if (pptp_session->snd_nxt == pptp_session->snd_una) { ack -= session->proto.pptp.snd_gap; pptp_session->ul_snd_una = ack; } else { /* * There are sending packets they are not acked. * In this situation, (ack - snd_gap) may points * before sending window of userland. So we don't * update the ack number. */ ack = pptp_session->ul_snd_una; } PUTLONG(ack, ackp); } return (m0); out_seq: pipex_session_log(session, LOG_DEBUG, "Received bad data packet: %s: seq=%u(%u-%u) ack=%u(%u-%u)", reason, seq, pptp_session->rcv_nxt, pptp_session->rcv_nxt + pptp_session->maxwinsz, ack, pptp_session->snd_una, pptp_session->snd_nxt); /* FALLTHROUGH */ drop: m_freem(m0); session->stat.ierrors++; return (NULL); } struct pipex_session * pipex_pptp_userland_lookup_session_ipv4(struct mbuf *m0, struct in_addr dst) { struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = dst; return pipex_pptp_userland_lookup_session(m0, sintosa(&sin)); } #ifdef INET6 struct pipex_session * pipex_pptp_userland_lookup_session_ipv6(struct mbuf *m0, struct in6_addr dst) { struct sockaddr_in6 sin6; memset(&sin6, 0, sizeof(sin6)); sin6.sin6_len = sizeof(sin6); sin6.sin6_family = AF_INET6; in6_recoverscope(&sin6, &dst); return pipex_pptp_userland_lookup_session(m0, sin6tosa(&sin6)); } #endif Static struct pipex_session * pipex_pptp_userland_lookup_session(struct mbuf *m0, struct sockaddr *sa) { struct pipex_gre_header gre; struct pipex_hash_head *list; struct pipex_session *session; uint16_t id, flags; /* pullup */ if (m0->m_pkthdr.len < sizeof(gre)) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> packet length is too short", __func__)); return (NULL); } /* get flags */ m_copydata(m0, 0, sizeof(struct pipex_gre_header), (caddr_t)&gre); flags = ntohs(gre.flags); /* gre version must be '1' */ if ((flags & PIPEX_GRE_VERMASK) != PIPEX_GRE_VER) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> gre header wrong version.", __func__)); return (NULL); } /* gre keys must be present */ if ((flags & PIPEX_GRE_KFLAG) == 0) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> gre header has no keys.", __func__)); return (NULL); } /* lookup pipex session table */ id = ntohs(gre.call_id); list = PIPEX_PEER_ADDR_HASHTABLE(pipex_sockaddr_hash_key(sa)); LIST_FOREACH(session, list, peer_addr_chain) { if (pipex_sockaddr_compar_addr( (struct sockaddr *)&session->peer, sa) != 0) continue; if (session->peer_session_id == id) break; } #ifdef PIPEX_DEBUG if (session == NULL) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (,call_id=%d)", __func__, (int)gre.call_id)); } #endif return (session); } /* * pipex_pptp_userland_output */ struct mbuf * pipex_pptp_userland_output(struct mbuf *m0, struct pipex_session *session) { int len; struct pipex_gre_header *gre, gre0; uint16_t flags; u_char *cp, *cp0; uint32_t val32; len = sizeof(struct pipex_gre_header); m_copydata(m0, 0, len, (caddr_t)&gre0); gre = &gre0; flags = ntohs(gre->flags); if ((flags & PIPEX_GRE_SFLAG) != 0) len += 4; if ((flags & PIPEX_GRE_AFLAG) != 0) len += 4; /* check length */ PIPEX_PULLUP(m0, len); if (m0 == NULL) { PIPEX_DBG((session, LOG_DEBUG, "gre header is too short.")); return (NULL); } gre = mtod(m0, struct pipex_gre_header *); cp = PIPEX_SEEK_NEXTHDR(gre, sizeof(struct pipex_gre_header), u_char *); /* * overwrite sequence numbers to adjust a gap between pipex and * userland. */ if ((flags & PIPEX_GRE_SFLAG) != 0) { cp0 = cp; GETLONG(val32, cp); val32 += session->proto.pptp.snd_gap; PUTLONG(val32, cp0); session->proto.pptp.snd_nxt++; } if ((flags & PIPEX_GRE_AFLAG) != 0) { cp0 = cp; GETLONG(val32, cp); val32 += session->proto.pptp.rcv_gap; PUTLONG(val32, cp0); if (SEQ32_GT(val32, session->proto.pptp.rcv_acked)) session->proto.pptp.rcv_acked = val32; } return (m0); } #endif /* PIPEX_PPTP */ #ifdef PIPEX_L2TP /*********************************************************************** * L2TP support ***********************************************************************/ Static void pipex_l2tp_output(struct mbuf *m0, struct pipex_session *session) { int hlen, plen, datalen; struct pipex_l2tp_header *l2tp = NULL; struct pipex_l2tp_seq_header *seq = NULL; struct udphdr *udp; struct ip *ip; #ifdef INET6 struct ip6_hdr *ip6; #endif hlen = sizeof(struct pipex_l2tp_header) + ((pipex_session_is_l2tp_data_sequencing_on(session)) ? sizeof(struct pipex_l2tp_seq_header) : 0) + sizeof(struct udphdr) + #ifdef INET6 ((session->peer.sin6.sin6_family == AF_INET6) ? sizeof(struct ip6_hdr) : sizeof(struct ip)); #else sizeof(struct ip); #endif datalen = 0; if (m0 != NULL) { datalen = m0->m_pkthdr.len; M_PREPEND(m0, hlen, M_NOWAIT); if (m0 == NULL) goto drop; } else { MGETHDR(m0, M_DONTWAIT, MT_DATA); if (m0 == NULL) goto drop; KASSERT(hlen <= MHLEN); m0->m_pkthdr.len = m0->m_len = hlen; } #ifdef INET6 hlen = (session->peer.sin6.sin6_family == AF_INET6) ? sizeof(struct ip6_hdr) : sizeof(struct ip); #else hlen = sizeof(struct ip); #endif plen = datalen + sizeof(struct pipex_l2tp_header) + ((pipex_session_is_l2tp_data_sequencing_on(session)) ? sizeof(struct pipex_l2tp_seq_header) : 0); l2tp = (struct pipex_l2tp_header *) (mtod(m0, caddr_t) + hlen + sizeof(struct udphdr)); l2tp->flagsver = PIPEX_L2TP_VER | PIPEX_L2TP_FLAG_LENGTH; l2tp->length = htons(plen); l2tp->tunnel_id = htons(session->proto.l2tp.peer_tunnel_id); l2tp->session_id = htons(session->peer_session_id); if (pipex_session_is_l2tp_data_sequencing_on(session)) { seq = (struct pipex_l2tp_seq_header *)(l2tp + 1); l2tp->flagsver |= PIPEX_L2TP_FLAG_SEQUENCE; seq->ns = htons(session->proto.l2tp.ns_nxt); session->proto.l2tp.ns_nxt++; session->proto.l2tp.ns_gap++; session->proto.l2tp.nr_acked = session->proto.l2tp.nr_nxt - 1; seq->nr = htons(session->proto.l2tp.nr_acked); } l2tp->flagsver = htons(l2tp->flagsver); plen += sizeof(struct udphdr); udp = (struct udphdr *)(mtod(m0, caddr_t) + hlen); udp->uh_sport = session->local.sin6.sin6_port; udp->uh_dport = session->peer.sin6.sin6_port; udp->uh_ulen = htons(plen); udp->uh_sum = 0; m0->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; m0->m_pkthdr.ph_ifidx = session->pipex_iface->ifnet_this->if_index; #if NPF > 0 pf_pkt_addr_changed(m0); #endif switch (session->peer.sin6.sin6_family) { case AF_INET: ip = mtod(m0, struct ip *); ip->ip_p = IPPROTO_UDP; ip->ip_src = session->local.sin4.sin_addr; ip->ip_dst = session->peer.sin4.sin_addr; ip->ip_len = htons(hlen + plen); ip->ip_ttl = MAXTTL; ip->ip_tos = 0; ip->ip_off = 0; if (ip_output(m0, NULL, NULL, 0, NULL, NULL, session->proto.l2tp.ipsecflowinfo) != 0) { PIPEX_DBG((session, LOG_DEBUG, "ip_output failed.")); goto drop; } break; #ifdef INET6 case AF_INET6: ip6 = mtod(m0, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_UDP; ip6->ip6_src = session->local.sin6.sin6_addr; (void)in6_embedscope(&ip6->ip6_dst, &session->peer.sin6, NULL); /* ip6->ip6_plen will be filled in ip6_output. */ if (ip6_output(m0, NULL, NULL, 0, NULL, NULL) != 0) { PIPEX_DBG((session, LOG_DEBUG, "ip6_output failed.")); goto drop; } break; #endif } udpstat_inc(udps_opackets); if (datalen > 0) { /* network layer only */ /* countup statistics */ session->stat.opackets++; session->stat.obytes += datalen; } return; drop: session->stat.oerrors++; } struct pipex_session * pipex_l2tp_lookup_session(struct mbuf *m0, int off) { struct pipex_session *session; uint16_t flags, session_id, ver; u_char *cp, buf[PIPEX_L2TP_MINLEN]; if (m0->m_pkthdr.len < off + PIPEX_L2TP_MINLEN) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> packet length is too short", __func__)); goto not_ours; } /* get first 16bits of L2TP */ m_copydata(m0, off, sizeof(buf), buf); cp = buf; GETSHORT(flags, cp); ver = flags & PIPEX_L2TP_VER_MASK; /* l2tp version must be '2' */ if (ver != PIPEX_L2TP_VER) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> l2tp header wrong version %u.", __func__, ver)); goto not_ours; } if ((flags & PIPEX_L2TP_FLAG_TYPE) != 0) goto not_ours; if (flags & PIPEX_L2TP_FLAG_LENGTH) cp += 2; /* skip length field */ cp += 2; /* skip tunnel-id field */ GETSHORT(session_id, cp); /* get session-id field */ /* lookup pipex session table */ session = pipex_lookup_by_session_id(PIPEX_PROTO_L2TP, session_id); #ifdef PIPEX_DEBUG if (session == NULL) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found (id=%d)", __func__, session_id)); goto not_ours; } #endif return (session); not_ours: return (NULL); } struct mbuf * pipex_l2tp_input(struct mbuf *m0, int off0, struct pipex_session *session, uint32_t ipsecflowinfo) { struct pipex_l2tp_session *l2tp_session; int length, offset, hlen, nseq; u_char *cp, *nsp, *nrp; uint16_t flags, ns = 0, nr = 0; int rewind = 0; length = offset = ns = nr = 0; l2tp_session = &session->proto.l2tp; l2tp_session->ipsecflowinfo = ipsecflowinfo; nsp = nrp = NULL; m_copydata(m0, off0, sizeof(flags), (caddr_t)&flags); flags = ntohs(flags) & PIPEX_L2TP_FLAG_MASK; KASSERT((flags & PIPEX_L2TP_FLAG_TYPE) == 0); hlen = 2; /* flags and version fields */ if (flags & PIPEX_L2TP_FLAG_LENGTH) /* length */ hlen += 2; hlen += 4; /* tunnel-id and session-id */ if (flags & PIPEX_L2TP_FLAG_SEQUENCE) /* ns and nr */ hlen += 4; if (flags & PIPEX_L2TP_FLAG_OFFSET) /* offset */ hlen += 2; PIPEX_PULLUP(m0, off0 + hlen); if (m0 == NULL) goto drop; cp = mtod(m0, u_char *) + off0; cp += 2; /* flags and version */ if (flags & PIPEX_L2TP_FLAG_LENGTH) GETSHORT(length, cp); else length = m0->m_pkthdr.len - off0; cp += 4; /* skip tunnel-id and session-id field */ /* pullup for seek sequences in header */ nseq = 0; if (flags & PIPEX_L2TP_FLAG_SEQUENCE) { nsp = cp; GETSHORT(ns, cp); nrp = cp; GETSHORT(nr, cp); nr++; if (SEQ16_GT(nr, l2tp_session->ns_una) && SEQ16_LE(nr, l2tp_session->ns_nxt)) /* update 'ns_una' only if the ns is in valid range */ l2tp_session->ns_una = nr; if (SEQ16_LT(ns, l2tp_session->nr_nxt)) { rewind = 1; if (SEQ16_LT(ns, l2tp_session->nr_nxt - PIPEX_REWIND_LIMIT)) goto out_seq; } ns++; nseq = SEQ16_SUB(ns, l2tp_session->nr_nxt); if (!rewind) l2tp_session->nr_nxt = ns; } if (flags & PIPEX_L2TP_FLAG_OFFSET) GETSHORT(offset, cp); length -= hlen + offset; hlen += off0 + offset; if ((m0 = pipex_common_input(session, m0, hlen, length)) == NULL) { /* ok, The packet is for PIPEX */ if (!rewind) session->proto.l2tp.nr_gap += nseq; return (NULL); } if (rewind) goto out_seq; /* * overwrite sequence numbers to adjust a gap between pipex and * userland. */ if (flags & PIPEX_L2TP_FLAG_SEQUENCE) { --ns; --nr; /* revert original values */ ns -= l2tp_session->nr_gap; PUTSHORT(ns, nsp); if (l2tp_session->ns_nxt == l2tp_session->ns_una) { nr -= l2tp_session->ns_gap; l2tp_session->ul_ns_una = nr; } else { /* * There are sending packets they are not acked. * In this situation, (ack - snd_gap) may points * before sending window of userland. So we don't * update the ack number. */ nr = l2tp_session->ul_ns_una; } PUTSHORT(nr, nrp); } return (m0); out_seq: pipex_session_log(session, LOG_DEBUG, "Received bad data packet: out of sequence: seq=%u(%u-) " "ack=%u(%u-%u)", ns, l2tp_session->nr_nxt, nr, l2tp_session->ns_una, l2tp_session->ns_nxt); /* FALLTHROUGH */ drop: m_freem(m0); session->stat.ierrors++; return (NULL); } struct pipex_session * pipex_l2tp_userland_lookup_session_ipv4(struct mbuf *m0, struct in_addr dst) { struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = dst; return pipex_l2tp_userland_lookup_session(m0, sintosa(&sin)); } #ifdef INET6 struct pipex_session * pipex_l2tp_userland_lookup_session_ipv6(struct mbuf *m0, struct in6_addr dst) { struct sockaddr_in6 sin6; memset(&sin6, 0, sizeof(sin6)); sin6.sin6_len = sizeof(sin6); sin6.sin6_family = AF_INET6; in6_recoverscope(&sin6, &dst); return pipex_l2tp_userland_lookup_session(m0, sin6tosa(&sin6)); } #endif struct pipex_session * pipex_l2tp_userland_lookup_session(struct mbuf *m0, struct sockaddr *sa) { struct pipex_l2tp_header l2tp; struct pipex_hash_head *list; struct pipex_session *session; uint16_t session_id, tunnel_id, flags; if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6) return (NULL); /* pullup */ if (m0->m_pkthdr.len < sizeof(l2tp)) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> packet length is too short", __func__)); return (NULL); } /* get flags */ m_copydata(m0, 0, sizeof(l2tp), (caddr_t)&l2tp); flags = ntohs(l2tp.flagsver); /* l2tp version must be '2' */ if ((flags & PIPEX_L2TP_VER_MASK) != PIPEX_L2TP_VER) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> l2tp header wrong version.", __func__)); return (NULL); } /* We need L2TP data messages only */ if ((flags & PIPEX_L2TP_FLAG_TYPE) != 0) return (NULL); /* No need to hook packets that don't have the sequence field */ if ((flags & PIPEX_L2TP_FLAG_SEQUENCE) == 0) return (NULL); session_id = ntohs(l2tp.session_id); tunnel_id = ntohs(l2tp.tunnel_id); list = PIPEX_PEER_ADDR_HASHTABLE(pipex_sockaddr_hash_key(sa)); LIST_FOREACH(session, list, peer_addr_chain) { if (pipex_sockaddr_compar_addr( (struct sockaddr *)&session->peer, sa) != 0) continue; if (session->proto.l2tp.peer_tunnel_id != tunnel_id) continue; if (session->peer_session_id == session_id) break; } #ifdef PIPEX_DEBUG if (session == NULL) { PIPEX_DBG((NULL, LOG_DEBUG, "<%s> session not found " "(tunnel_id=%d, session_id=%d)", __func__, tunnel_id, session_id)); } #endif return (session); } struct mbuf * pipex_l2tp_userland_output(struct mbuf *m0, struct pipex_session *session) { struct pipex_l2tp_header *l2tp; struct pipex_l2tp_seq_header *seq; uint16_t ns, nr; /* check length */ PIPEX_PULLUP(m0, sizeof(struct pipex_l2tp_header) + sizeof(struct pipex_l2tp_seq_header)); if (m0 == NULL) return (NULL); l2tp = mtod(m0, struct pipex_l2tp_header *); KASSERT(ntohs(l2tp->flagsver) & PIPEX_L2TP_FLAG_SEQUENCE); /* * overwrite sequence numbers to adjust a gap between pipex and * userland. */ seq = (struct pipex_l2tp_seq_header *)(l2tp + 1); ns = ntohs(seq->ns); nr = ntohs(seq->nr); ns += session->proto.l2tp.ns_gap; seq->ns = htons(ns); session->proto.l2tp.ns_nxt++; nr += session->proto.l2tp.nr_gap; seq->nr = htons(nr); if (SEQ16_GT(nr, session->proto.l2tp.nr_acked)) session->proto.l2tp.nr_acked = nr; return (m0); } #endif /* PIPEX_L2TP */ #ifdef PIPEX_MPPE /********************************************************************** * MPPE ***********************************************************************/ #define PIPEX_COHERENCY_CNT_MASK 0x0fff Static void pipex_mppe_init(struct pipex_mppe *mppe, int stateless, int keylenbits, u_char *master_key, int has_oldkey) { memset(mppe, 0, sizeof(struct pipex_mppe)); if (stateless) mppe->stateless = 1; if (has_oldkey) mppe->old_session_keys = pool_get(&mppe_key_pool, PR_WAITOK); else mppe->old_session_keys = NULL; memcpy(mppe->master_key, master_key, sizeof(mppe->master_key)); mppe->keylenbits = keylenbits; switch (keylenbits) { case 40: case 56: mppe->keylen = 8; break; case 128: mppe->keylen = 16; break; } GetNewKeyFromSHA(mppe->master_key, mppe->master_key, mppe->keylen, mppe->session_key); pipex_mppe_reduce_key(mppe); pipex_mppe_setkey(mppe); } void pipex_session_init_mppe_recv(struct pipex_session *session, int stateless, int keylenbits, u_char *master_key) { pipex_mppe_init(&session->mppe_recv, stateless, keylenbits, master_key, stateless); session->ppp_flags |= PIPEX_PPP_MPPE_ACCEPTED; } void pipex_session_init_mppe_send(struct pipex_session *session, int stateless, int keylenbits, u_char *master_key) { pipex_mppe_init(&session->mppe_send, stateless, keylenbits, master_key, 0); session->ppp_flags |= PIPEX_PPP_MPPE_ENABLED; } #include static u_char SHAPad1[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, SHAPad2[] = { 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, }; Static void GetNewKeyFromSHA(u_char *StartKey, u_char *SessionKey, int SessionKeyLength, u_char *InterimKey) { u_char Digest[20]; SHA1_CTX Context; SHA1Init(&Context); SHA1Update(&Context, StartKey, SessionKeyLength); SHA1Update(&Context, SHAPad1, 40); SHA1Update(&Context, SessionKey, SessionKeyLength); SHA1Update(&Context, SHAPad2, 40); SHA1Final(Digest, &Context); memcpy(InterimKey, Digest, SessionKeyLength); } Static void pipex_mppe_reduce_key(struct pipex_mppe *mppe) { switch (mppe->keylenbits) { case 40: mppe->session_key[1] = 0x26; mppe->session_key[2] = 0x9e; case 56: mppe->session_key[0] = 0xd1; } } Static void mppe_key_change(struct pipex_mppe *mppe) { u_char interim[16]; struct rc4_ctx keychg; memset(&keychg, 0, sizeof(keychg)); GetNewKeyFromSHA(mppe->master_key, mppe->session_key, mppe->keylen, interim); rc4_keysetup(&keychg, interim, mppe->keylen); rc4_crypt(&keychg, interim, mppe->session_key, mppe->keylen); pipex_mppe_reduce_key(mppe); if (mppe->old_session_keys) { int idx = mppe->coher_cnt & PIPEX_MPPE_OLDKEYMASK; memcpy(mppe->old_session_keys[idx], mppe->session_key, PIPEX_MPPE_KEYLEN); } } Static void pipex_mppe_input(struct mbuf *m0, struct pipex_session *session) { int pktloss, encrypt, flushed, m, n, len; struct pipex_mppe *mppe; uint16_t coher_cnt; struct mbuf *m1; u_char *cp; int rewind = 0; /* pullup */ PIPEX_PULLUP(m0, sizeof(coher_cnt)); if (m0 == NULL) goto drop; mppe = &session->mppe_recv; /* get header information */ cp = mtod(m0, u_char *); GETSHORT(coher_cnt, cp); flushed = ((coher_cnt & 0x8000) != 0) ? 1 : 0; encrypt = ((coher_cnt & 0x1000) != 0) ? 1 : 0; coher_cnt &= PIPEX_COHERENCY_CNT_MASK; pktloss = 0; PIPEX_MPPE_DBG((session, LOG_DEBUG, "in coher_cnt=%03x %s%s", mppe->coher_cnt, (flushed) ? "[flushed]" : "", (encrypt) ? "[encrypt]" : "")); if (encrypt == 0) { pipex_session_log(session, LOG_DEBUG, "Received unexpected MPPE packet.(no ecrypt)"); goto drop; } /* adjust mbuf */ m_adj(m0, sizeof(coher_cnt)); /* * L2TP data session may be used without sequencing, PPP frames may * arrive in disorder. The 'coherency counter' of MPPE detects such * situations, but we cannot distinguish between 'disorder' and * 'packet loss' exactly. * * When 'coherency counter' detects lost packets greater than * (4096 - 256), we treat as 'disorder' otherwise treat as * 'packet loss'. */ { int coher_cnt0; coher_cnt0 = coher_cnt; if (coher_cnt < mppe->coher_cnt) coher_cnt0 += 0x1000; if (coher_cnt0 - mppe->coher_cnt > 0x0f00) { if (!mppe->stateless || coher_cnt0 - mppe->coher_cnt <= 0x1000 - PIPEX_MPPE_NOLDKEY) { pipex_session_log(session, LOG_DEBUG, "Workaround the out-of-sequence PPP framing problem: " "%d => %d", mppe->coher_cnt, coher_cnt); goto drop; } rewind = 1; } } if (mppe->stateless != 0) { if (!rewind) { mppe_key_change(mppe); while (mppe->coher_cnt != coher_cnt) { mppe->coher_cnt++; mppe->coher_cnt &= PIPEX_COHERENCY_CNT_MASK; mppe_key_change(mppe); pktloss++; } } pipex_mppe_setoldkey(mppe, coher_cnt); } else { if (flushed) { if (coher_cnt < mppe->coher_cnt) { coher_cnt += 0x1000; } pktloss += coher_cnt - mppe->coher_cnt; m = mppe->coher_cnt / 256; n = coher_cnt / 256; while (m++ < n) mppe_key_change(mppe); coher_cnt &= PIPEX_COHERENCY_CNT_MASK; mppe->coher_cnt = coher_cnt; } else if (mppe->coher_cnt != coher_cnt) { /* Send CCP ResetReq */ PIPEX_DBG((session, LOG_DEBUG, "CCP SendResetReq")); pipex_ccp_output(session, CCP_RESETREQ, session->ccp_id++); goto drop; } if ((coher_cnt & 0xff) == 0xff) { mppe_key_change(mppe); flushed = 1; } if (flushed) pipex_mppe_setkey(mppe); } if (pktloss > 1000) { pipex_session_log(session, LOG_DEBUG, "%d packets loss.", pktloss); } /* decrypt ppp payload */ for (m1 = m0; m1; m1 = m1->m_next) { cp = mtod(m1, u_char *); len = m1->m_len; pipex_mppe_crypt(mppe, len, cp, cp); } if (!rewind) { /* update coher_cnt */ mppe->coher_cnt++; mppe->coher_cnt &= PIPEX_COHERENCY_CNT_MASK; } if (m0->m_pkthdr.len < PIPEX_PPPMINLEN) goto drop; pipex_ppp_input(m0, session, 1); return; drop: m_freem(m0); session->stat.ierrors++; } Static void pipex_mppe_output(struct mbuf *m0, struct pipex_session *session, uint16_t protocol) { int encrypt, flushed, len; struct mppe_header { uint16_t coher_cnt; uint16_t protocol; } __packed *hdr; u_char *cp; struct pipex_mppe *mppe; struct mbuf *m; mppe = &session->mppe_send; /* * create a deep-copy if the mbuf has a shared mbuf cluster. * this is required to handle cases of tcp retransmition. */ for (m = m0; m != NULL; m = m->m_next) { if (M_READONLY(m)) { m = m_dup_pkt(m0, max_linkhdr, M_NOWAIT); m_freem(m0); if (m == NULL) goto drop; m0 = m; break; } } /* prepend mppe header */ M_PREPEND(m0, sizeof(struct mppe_header), M_NOWAIT); if (m0 == NULL) goto drop; hdr = mtod(m0, struct mppe_header *); hdr->protocol = protocol; /* check coherency counter */ flushed = 0; encrypt = 1; if (mppe->stateless != 0) { flushed = 1; mppe_key_change(mppe); } else { if ((mppe->coher_cnt % 0x100) == 0xff) { flushed = 1; mppe_key_change(mppe); } else if (mppe->resetreq != 0) { flushed = 1; mppe->resetreq = 0; } } if (flushed) pipex_mppe_setkey(mppe); PIPEX_MPPE_DBG((session, LOG_DEBUG, "out coher_cnt=%03x %s%s", mppe->coher_cnt, (flushed) ? "[flushed]" : "", (encrypt) ? "[encrypt]" : "")); /* setup header information */ hdr->coher_cnt = (mppe->coher_cnt++) & PIPEX_COHERENCY_CNT_MASK; hdr->coher_cnt &= PIPEX_COHERENCY_CNT_MASK; if (flushed) hdr->coher_cnt |= 0x8000; if (encrypt) hdr->coher_cnt |= 0x1000; hdr->protocol = htons(hdr->protocol); hdr->coher_cnt = htons(hdr->coher_cnt); /* encrypt chain */ for (m = m0; m; m = m->m_next) { cp = mtod(m, u_char *); len = m->m_len; if (m == m0 && len > offsetof(struct mppe_header, protocol)) { len -= offsetof(struct mppe_header, protocol); cp += offsetof(struct mppe_header, protocol); } pipex_mppe_crypt(mppe, len, cp, cp); } pipex_ppp_output(m0, session, PPP_COMP); return; drop: session->stat.oerrors++; } Static void pipex_ccp_input(struct mbuf *m0, struct pipex_session *session) { u_char *cp; int code, id, len; if (m0->m_pkthdr.len < PPP_HDRLEN) goto drop; if ((m0 = m_pullup(m0, PPP_HDRLEN)) == NULL) goto drop; cp = mtod(m0, u_char *); GETCHAR(code, cp); GETCHAR(id, cp); GETSHORT(len, cp); switch (code) { case CCP_RESETREQ: PIPEX_DBG((session, LOG_DEBUG, "CCP RecvResetReq")); session->mppe_send.resetreq = 1; #ifndef PIPEX_NO_CCP_RESETACK PIPEX_DBG((session, LOG_DEBUG, "CCP SendResetAck")); pipex_ccp_output(session, CCP_RESETACK, id); #endif /* ignore error */ break; case CCP_RESETACK: PIPEX_DBG((session, LOG_DEBUG, "CCP RecvResetAck")); break; default: PIPEX_DBG((session, LOG_DEBUG, "CCP Recv code=%d", code)); goto drop; } m_freem(m0); return; drop: m_freem(m0); session->stat.ierrors++; } Static int pipex_ccp_output(struct pipex_session *session, int code, int id) { u_char *cp; struct mbuf *m; MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) { session->stat.oerrors++; return (1); } m->m_pkthdr.len = m->m_len = 4; cp = mtod(m, u_char *); PUTCHAR(code, cp); PUTCHAR(id, cp); PUTSHORT(4, cp); pipex_ppp_output(m, session, PPP_CCP); return (0); } #endif /*********************************************************************** * Miscellaneous fuctions ***********************************************************************/ /* adapted from FreeBSD:src/usr.sbin/ppp/tcpmss.c */ /* * Copyright (c) 2000 Ruslan Ermilov and Brian Somers * 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. * * $FreeBSD: src/usr.sbin/ppp/tcpmss.c,v 1.1.4.3 2001/07/19 11:39:54 brian Exp $ */ #define TCP_OPTLEN_IN_SEGMENT 12 /* timestamp option and padding */ #define MAXMSS(mtu) (mtu - sizeof(struct ip) - sizeof(struct tcphdr) - \ TCP_OPTLEN_IN_SEGMENT) /* * The following macro is used to update an internet checksum. "acc" is a * 32-bit accumulation of all the changes to the checksum (adding in old * 16-bit words and subtracting out new words), and "cksum" is the checksum * value to be updated. */ #define ADJUST_CHECKSUM(acc, cksum) { \ acc += cksum; \ if (acc < 0) { \ acc = -acc; \ acc = (acc >> 16) + (acc & 0xffff); \ acc += acc >> 16; \ cksum = (u_short) ~acc; \ } else { \ acc = (acc >> 16) + (acc & 0xffff); \ acc += acc >> 16; \ cksum = (u_short) acc; \ } \ } /* * Rewrite max-segment-size TCP option to avoid PMTU blackhole issues. * The mtu parameter should be the MTU bottleneck (as far as we know) * on the link between the source and the destination. */ Static struct mbuf * adjust_tcp_mss(struct mbuf *m0, int mtu) { int opt, optlen, acc, mss, maxmss, lpktp; struct ip *pip; struct tcphdr *th; u_char *pktp, *mssp; u_int16_t ip_off; lpktp = sizeof(struct ip) + sizeof(struct tcphdr) + PIPEX_TCP_OPTLEN; lpktp = MIN(lpktp, m0->m_pkthdr.len); PIPEX_PULLUP(m0, lpktp); if (m0 == NULL) goto drop; pktp = mtod(m0, char *); pip = (struct ip *)pktp; ip_off = ntohs(pip->ip_off); /* Non TCP or fragmented packet must not have a MSS option */ if (pip->ip_p != IPPROTO_TCP || (ip_off & IP_MF) != 0 || (ip_off & IP_OFFMASK) != 0) goto handled; pktp += pip->ip_hl << 2; lpktp -= pip->ip_hl << 2; /* packet is broken */ if (sizeof(struct tcphdr) > lpktp) goto drop; th = (struct tcphdr *)pktp; /* * As RFC 973, a MSS field must only be sent in the initial * connection request(it must be with SYN). */ if ((th->th_flags & TH_SYN) == 0) goto handled; lpktp = MIN(th->th_off << 4, lpktp); pktp += sizeof(struct tcphdr); lpktp -= sizeof(struct tcphdr); while (lpktp >= TCPOLEN_MAXSEG) { GETCHAR(opt, pktp); switch (opt) { case TCPOPT_MAXSEG: GETCHAR(optlen, pktp); mssp = pktp; /* mss place holder */ GETSHORT(mss, pktp); maxmss = MAXMSS(mtu); if (mss > maxmss) { PIPEX_DBG((NULL, LOG_DEBUG, "change tcp-mss %d => %d", mss, maxmss)); PUTSHORT(maxmss, mssp); acc = htons(mss); acc -= htons(maxmss); ADJUST_CHECKSUM(acc, th->th_sum); } goto handled; /* NOTREACHED */ case TCPOPT_EOL: goto handled; /* NOTREACHED */ case TCPOPT_NOP: lpktp--; break; default: GETCHAR(optlen, pktp); if (optlen < 2) /* packet is broken */ goto drop; pktp += optlen - 2; lpktp -= optlen; break; } } handled: return (m0); drop: m_freem(m0); return (NULL); } /* * Check whether a packet should reset idle timer * Returns 1 to don't reset timer (i.e. the packet is "idle" packet) */ Static struct mbuf * ip_is_idle_packet(struct mbuf *m0, int *ris_idle) { u_int16_t ip_off; const struct udphdr *uh; struct ip *pip; int len; /* pullup ip header */ len = sizeof(struct ip); PIPEX_PULLUP(m0, len); if (m0 == NULL) goto error; pip = mtod(m0, struct ip *); /* * the packet which fragmentations was not the idle packet. */ ip_off = ntohs(pip->ip_off); if ((ip_off & IP_MF) || ((ip_off & IP_OFFMASK) != 0)) goto is_active; switch (pip->ip_p) { case IPPROTO_IGMP: goto is_active; case IPPROTO_ICMP: len = pip->ip_hl * 4 + 8; PIPEX_PULLUP(m0, len); if (m0 == NULL) goto error; pip = mtod(m0, struct ip *); switch (((unsigned char *) pip)[pip->ip_hl * 4]) { case 0: /* Echo Reply */ case 8: /* Echo Request */ goto is_active; default: goto is_idle; } case IPPROTO_UDP: case IPPROTO_TCP: len = pip->ip_hl * 4 + sizeof(struct udphdr); PIPEX_PULLUP(m0, len); if (m0 == NULL) goto error; pip = mtod(m0, struct ip *); uh = (struct udphdr *)(mtod(m0, caddr_t) + pip->ip_hl * 4); switch (ntohs(uh->uh_sport)) { case 53: /* DOMAIN */ case 67: /* BOOTPS */ case 68: /* BOOTPC */ case 123: /* NTP */ case 137: /* NETBIOS-NS */ case 520: /* RIP */ goto is_idle; } switch (ntohs(uh->uh_dport)) { case 53: /* DOMAIN */ case 67: /* BOOTPS */ case 68: /* BOOTPC */ case 123: /* NTP */ case 137: /* NETBIOS-NS */ case 520: /* RIP */ goto is_idle; } goto is_active; default: goto is_active; } is_active: *ris_idle = 0; return (m0); is_idle: *ris_idle = 1; return (m0); error: return (NULL); } Static void pipex_session_log(struct pipex_session *session, int prio, const char *fmt, ...) { char logbuf[1024]; va_list ap; logpri(prio); if (session != NULL) { addlog("pipex: ppp=%d iface=%s protocol=%s id=%d ", session->ppp_id, session->pipex_iface->ifnet_this->if_xname, (session->protocol == PIPEX_PROTO_PPPOE)? "PPPoE" : (session->protocol == PIPEX_PROTO_PPTP)? "PPTP" : (session->protocol == PIPEX_PROTO_L2TP) ? "L2TP" : "Unknown", session->session_id); } else addlog("pipex: "); va_start(ap, fmt); vsnprintf(logbuf, sizeof(logbuf), fmt, ap); va_end(ap); addlog("%s\n", logbuf); } Static uint32_t pipex_sockaddr_hash_key(struct sockaddr *sa) { switch (sa->sa_family) { case AF_INET: return ntohl(satosin(sa)->sin_addr.s_addr); case AF_INET6: return ntohl(satosin6(sa)->sin6_addr.s6_addr32[3]); } panic("pipex_sockaddr_hash_key: unknown address family"); return (0); } /* * Compare struct sockaddr_in{,6} with the address only. * The port number is not covered. */ Static int pipex_sockaddr_compar_addr(struct sockaddr *a, struct sockaddr *b) { int cmp; cmp = b->sa_family - a->sa_family; if (cmp != 0) return cmp; switch (a->sa_family) { case AF_INET: return (satosin(b)->sin_addr.s_addr - satosin(a)->sin_addr.s_addr); case AF_INET6: cmp = (satosin6(b)->sin6_scope_id - satosin6(a)->sin6_scope_id); if (cmp != 0) return cmp; return (memcmp(&satosin6(a)->sin6_addr, &satosin6(b)->sin6_addr, sizeof(struct in6_addr))); } panic("pipex_sockaddr_compar_addr: unknown address family"); return (-1); } Static inline int pipex_mppe_setkey(struct pipex_mppe *mppe) { rc4_keysetup(&mppe->rc4ctx, mppe->session_key, mppe->keylen); return (0); } Static inline int pipex_mppe_setoldkey(struct pipex_mppe *mppe, uint16_t coher_cnt) { KASSERT(mppe->old_session_keys != NULL); rc4_keysetup(&mppe->rc4ctx, mppe->old_session_keys[coher_cnt & PIPEX_MPPE_OLDKEYMASK], mppe->keylen); return (0); } Static inline void pipex_mppe_crypt(struct pipex_mppe *mppe, int len, u_char *indata, u_char *outdata) { rc4_crypt(&mppe->rc4ctx, indata, outdata, len); } int pipex_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { switch (name[0]) { case PIPEXCTL_ENABLE: if (namelen != 1) return (ENOTDIR); return (sysctl_int(oldp, oldlenp, newp, newlen, &pipex_enable)); case PIPEXCTL_INQ: return (sysctl_mq(name + 1, namelen - 1, oldp, oldlenp, newp, newlen, &pipexinq)); case PIPEXCTL_OUTQ: return (sysctl_mq(name + 1, namelen - 1, oldp, oldlenp, newp, newlen, &pipexoutq)); default: return (ENOPROTOOPT); } /* NOTREACHED */ }