/* $OpenBSD: pipex.c,v 1.149 2023/09/16 09:33:27 mpi 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 #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 #include #include "pipex_local.h" struct mutex pipex_list_mtx = MUTEX_INITIALIZER(IPL_SOFTNET); struct pool pipex_session_pool; struct pool mppe_key_pool; /* * Global data * Locks used to protect global data * A atomic operation * I immutable after creation * L pipex_list_mtx */ int pipex_enable = 0; /* [A] */ struct pipex_hash_head pipex_session_list, /* [L] master session list */ pipex_close_wait_list, /* [L] expired session list */ pipex_peer_addr_hashtable[PIPEX_HASH_SIZE], /* [L] peer's address hash */ pipex_id_hashtable[PIPEX_HASH_SIZE]; /* [L] peer id hash */ struct radix_node_head *pipex_rd_head4 = NULL; /* [L] */ struct radix_node_head *pipex_rd_head6 = NULL; /* [L] */ struct timeout pipex_timer_ch; /* callout timer context */ int pipex_prune = 1; /* [I] walk list every seconds */ struct mbuf_queue pipexoutq = MBUF_QUEUE_INITIALIZER( IFQ_MAXLEN, IPL_SOFTNET); /* borrow an mbuf pkthdr field */ #define ph_ppp_proto ether_vtag #ifdef PIPEX_DEBUG int pipex_debug = 0; /* [A] 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; static int pipex_init_done = 0; if (pipex_init_done++) return; rn_init(sizeof(struct sockaddr_in6)); pool_init(&pipex_session_pool, sizeof(struct pipex_session), 0, IPL_SOFTNET, PR_WAITOK, "ppxss", NULL); pool_init(&mppe_key_pool, PIPEX_MPPE_KEYLEN * PIPEX_MPPE_NOLDKEY, 0, IPL_SOFTNET, 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]); } void pipex_destroy_all_sessions(void *ownersc) { struct pipex_session *session, *session_tmp; mtx_enter(&pipex_list_mtx); LIST_FOREACH_SAFE(session, &pipex_session_list, session_list, session_tmp) { if (session->ownersc == ownersc) { KASSERT((session->flags & PIPEX_SFLAGS_PPPX) == 0); pipex_unlink_session_locked(session); pipex_rele_session(session); } } mtx_leave(&pipex_list_mtx); } int pipex_ioctl(void *ownersc, u_long cmd, caddr_t data) { int ret = 0; switch (cmd) { case PIPEXGSTAT: ret = pipex_get_stat((struct pipex_session_stat_req *)data, ownersc); break; case PIPEXGCLOSED: ret = pipex_get_closed((struct pipex_session_list_req *)data, ownersc); break; default: ret = ENOTTY; break; } return (ret); } /************************************************************************ * Software Interrupt Handler ************************************************************************/ void pipexintr(void) { struct mbuf_list ml; struct mbuf *m; struct pipex_session *session; NET_ASSERT_LOCKED(); mq_delist(&pipexoutq, &ml); while ((m = ml_dequeue(&ml)) != NULL) { struct ifnet *ifp; session = m->m_pkthdr.ph_cookie; ifp = if_get(session->proto.pppoe.over_ifidx); if (ifp != NULL) { struct pipex_pppoe_header *pppoe; int len; pppoe = mtod(m, struct pipex_pppoe_header *); len = ntohs(pppoe->length); ifp->if_output(ifp, m, &session->peer.sa, NULL); counters_pkt(session->stat_counters, pxc_opackets, pxc_obytes, len); } else { m_freem(m); counters_inc(session->stat_counters, pxc_oerrors); } if_put(ifp); pipex_rele_session(session); } } /************************************************************************ * Session management functions ************************************************************************/ int pipex_init_session(struct pipex_session **rsession, struct pipex_session_req *req) { struct pipex_session *session; #ifdef PIPEX_PPPOE struct ifnet *over_ifp = NULL; #endif /* Checks requested parameters. */ switch (req->pr_protocol) { #ifdef PIPEX_PPPOE case PIPEX_PROTO_PPPOE: if (req->pr_peer_address.ss_family != AF_UNSPEC) return (EINVAL); break; #endif #if defined(PIPEX_L2TP) || defined(PIPEX_PPTP) case PIPEX_PROTO_PPTP: case PIPEX_PROTO_L2TP: 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 /* defined(PIPEX_PPTP) || defined(PIPEX_L2TP) */ default: return (EPROTONOSUPPORT); } #ifdef PIPEX_MPPE if ((req->pr_ppp_flags & PIPEX_PPP_MPPE_ACCEPTED) != 0) { switch (req->pr_mppe_recv.keylenbits) { case 40: case 56: case 128: break; default: return (EINVAL); } } if ((req->pr_ppp_flags & PIPEX_PPP_MPPE_ENABLED) != 0) { switch (req->pr_mppe_send.keylenbits) { case 40: case 56: case 128: break; default: return (EINVAL); } } if ((req->pr_ppp_flags & PIPEX_PPP_MPPE_REQUIRED) != 0) { if ((req->pr_ppp_flags & (PIPEX_PPP_MPPE_ACCEPTED | PIPEX_PPP_MPPE_ENABLED)) != (PIPEX_PPP_MPPE_ACCEPTED | PIPEX_PPP_MPPE_ENABLED)) return (EINVAL); } #endif #ifdef PIPEX_PPPOE if (req->pr_protocol == PIPEX_PROTO_PPPOE) { over_ifp = if_unit(req->pr_proto.pppoe.over_ifname); if (over_ifp == NULL) return (EINVAL); } #endif /* prepare a new session */ session = pool_get(&pipex_session_pool, PR_WAITOK | PR_ZERO); refcnt_init(&session->pxs_refcnt); mtx_init(&session->pxs_mtx, IPL_SOFTNET); session->state = PIPEX_STATE_INITIAL; 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->ppp_flags = req->pr_ppp_flags; session->ppp_id = req->pr_ppp_id; session->stat_counters = counters_alloc(pxc_ncounters); 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_ifidx = over_ifp->if_index; if_put(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) { 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) { pipex_session_init_mppe_send(session, req->pr_mppe_send.stateless, req->pr_mppe_send.keylenbits, req->pr_mppe_send.master_key); } #endif *rsession = session; return 0; } void pipex_rele_session(struct pipex_session *session) { if (refcnt_rele(&session->pxs_refcnt) == 0) return; if (session->mppe_recv.old_session_keys) pool_put(&mppe_key_pool, session->mppe_recv.old_session_keys); counters_free(session->stat_counters, pxc_ncounters); pool_put(&pipex_session_pool, session); } int pipex_link_session(struct pipex_session *session, struct ifnet *ifp, void *ownersc) { struct pipex_hash_head *chain; struct radix_node *rn; int error = 0; mtx_enter(&pipex_list_mtx); if (pipex_rd_head4 == NULL) { if (!rn_inithead((void **)&pipex_rd_head4, offsetof(struct sockaddr_in, sin_addr))) panic("rn_inithead() failed on pipex_link_session()"); } if (pipex_rd_head6 == NULL) { if (!rn_inithead((void **)&pipex_rd_head6, offsetof(struct sockaddr_in6, sin6_addr))) panic("rn_inithead() failed on pipex_link_session()"); } if (pipex_lookup_by_session_id_locked(session->protocol, session->session_id)) { error = EEXIST; goto out; } session->ownersc = ownersc; session->ifindex = ifp->if_index; if (ifp->if_flags & IFF_POINTOPOINT) session->flags |= PIPEX_SFLAGS_PPPX; if ((session->flags & PIPEX_SFLAGS_PPPX) == 0 && !in_nullhost(session->ip_address.sin_addr)) { if (pipex_lookup_by_ip_address_locked( session->ip_address.sin_addr) != NULL) { error = EADDRINUSE; goto out; } rn = rn_addroute(&session->ip_address, &session->ip_netmask, pipex_rd_head4, session->ps4_rn, RTP_STATIC); if (rn == NULL) { error = ENOMEM; goto out; } } LIST_INSERT_HEAD(&pipex_session_list, session, session_list); chain = PIPEX_ID_HASHTABLE(session->session_id); LIST_INSERT_HEAD(chain, session, id_chain); #if defined(PIPEX_PPTP) || defined(PIPEX_L2TP) switch (session->protocol) { case PIPEX_PROTO_PPTP: case PIPEX_PROTO_L2TP: chain = PIPEX_PEER_ADDR_HASHTABLE( pipex_sockaddr_hash_key(&session->peer.sa)); LIST_INSERT_HEAD(chain, session, peer_addr_chain); } #endif /* if first session is added, start timer */ if (LIST_NEXT(session, session_list) == NULL) pipex_timer_start(); session->state = PIPEX_STATE_OPENED; out: mtx_leave(&pipex_list_mtx); return error; } void pipex_unlink_session_locked(struct pipex_session *session) { struct radix_node *rn; MUTEX_ASSERT_LOCKED(&pipex_list_mtx); session->ifindex = 0; if (session->state == PIPEX_STATE_CLOSED) return; if ((session->flags & PIPEX_SFLAGS_PPPX) == 0 && !in_nullhost(session->ip_address.sin_addr)) { KASSERT(pipex_rd_head4 != NULL); rn = rn_delete(&session->ip_address, &session->ip_netmask, pipex_rd_head4, (struct radix_node *)session); KASSERT(rn != NULL); } LIST_REMOVE(session, id_chain); #if defined(PIPEX_PPTP) || defined(PIPEX_L2TP) switch (session->protocol) { case PIPEX_PROTO_PPTP: case PIPEX_PROTO_L2TP: LIST_REMOVE(session, peer_addr_chain); break; } #endif if (session->state == PIPEX_STATE_CLOSE_WAIT) LIST_REMOVE(session, state_list); LIST_REMOVE(session, session_list); session->state = PIPEX_STATE_CLOSED; /* if final session is destroyed, stop timer */ if (LIST_EMPTY(&pipex_session_list)) pipex_timer_stop(); } void pipex_unlink_session(struct pipex_session *session) { mtx_enter(&pipex_list_mtx); pipex_unlink_session_locked(session); mtx_leave(&pipex_list_mtx); } int pipex_notify_close_session(struct pipex_session *session) { MUTEX_ASSERT_LOCKED(&pipex_list_mtx); session->state = PIPEX_STATE_CLOSE_WAIT; session->idle_time = 0; LIST_INSERT_HEAD(&pipex_close_wait_list, session, state_list); return (0); } void pipex_export_session_stats(struct pipex_session *session, struct pipex_statistics *stats) { uint64_t counters[pxc_ncounters]; memset(stats, 0, sizeof(*stats)); counters_read(session->stat_counters, counters, pxc_ncounters, NULL); stats->ipackets = counters[pxc_ipackets]; stats->ierrors = counters[pxc_ierrors]; stats->ibytes = counters[pxc_ibytes]; stats->opackets = counters[pxc_opackets]; stats->oerrors = counters[pxc_oerrors]; stats->obytes = counters[pxc_obytes]; stats->idle_time = session->idle_time; } int pipex_get_stat(struct pipex_session_stat_req *req, void *ownersc) { struct pipex_session *session; int error = 0; session = pipex_lookup_by_session_id(req->psr_protocol, req->psr_session_id); if (session == NULL) return (EINVAL); if (session->ownersc == ownersc) pipex_export_session_stats(session, &req->psr_stat); else error = EINVAL; pipex_rele_session(session); return error; } int pipex_get_closed(struct pipex_session_list_req *req, void *ownersc) { struct pipex_session *session, *session_tmp; bzero(req, sizeof(*req)); mtx_enter(&pipex_list_mtx); LIST_FOREACH_SAFE(session, &pipex_close_wait_list, state_list, session_tmp) { if (session->ownersc != ownersc) continue; 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; } } mtx_leave(&pipex_list_mtx); return (0); } struct pipex_session * pipex_lookup_by_ip_address_locked(struct in_addr addr) { struct pipex_session *session; struct sockaddr_in pipex_in4, pipex_in4mask; MUTEX_ASSERT_LOCKED(&pipex_list_mtx); if (pipex_rd_head4 == NULL) return (NULL); 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); } struct pipex_session * pipex_lookup_by_ip_address(struct in_addr addr) { struct pipex_session *session; mtx_enter(&pipex_list_mtx); session = pipex_lookup_by_ip_address_locked(addr); if (session != NULL) refcnt_take(&session->pxs_refcnt); mtx_leave(&pipex_list_mtx); return (session); } struct pipex_session * pipex_lookup_by_session_id_locked(int protocol, int session_id) { struct pipex_hash_head *list; struct pipex_session *session; MUTEX_ASSERT_LOCKED(&pipex_list_mtx); 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); } struct pipex_session * pipex_lookup_by_session_id(int protocol, int session_id) { struct pipex_session *session; mtx_enter(&pipex_list_mtx); session = pipex_lookup_by_session_id_locked(protocol, session_id); if (session != NULL) refcnt_take(&session->pxs_refcnt); mtx_leave(&pipex_list_mtx); return (session); } /*********************************************************************** * Timer functions ***********************************************************************/ void pipex_timer_start(void) { timeout_set_proc(&pipex_timer_ch, pipex_timer, NULL); timeout_add_sec(&pipex_timer_ch, pipex_prune); } void pipex_timer_stop(void) { timeout_del(&pipex_timer_ch); } void pipex_timer(void *ignored_arg) { struct pipex_session *session, *session_tmp; timeout_add_sec(&pipex_timer_ch, pipex_prune); mtx_enter(&pipex_list_mtx); /* walk through */ LIST_FOREACH_SAFE(session, &pipex_session_list, session_list, session_tmp) { switch (session->state) { case PIPEX_STATE_OPENED: if (session->timeout_sec == 0) continue; session->idle_time++; if (session->idle_time < session->timeout_sec) continue; pipex_notify_close_session(session); break; case PIPEX_STATE_CLOSE_WAIT: case PIPEX_STATE_CLOSE_WAIT2: /* Waiting PIPEXDSESSION from userland */ session->idle_time++; if (session->idle_time < PIPEX_CLOSE_TIMEOUT) continue; /* Release the sessions when timeout */ pipex_unlink_session_locked(session); KASSERTMSG((session->flags & PIPEX_SFLAGS_PPPX) == 0, "FIXME session must not be released when pppx"); pipex_rele_session(session); break; default: break; } } mtx_leave(&pipex_list_mtx); } /*********************************************************************** * Common network I/O functions. (tunnel protocol independent) ***********************************************************************/ void pipex_ip_output(struct mbuf *m0, struct pipex_session *session) { int is_idle; if ((session->flags & PIPEX_SFLAGS_MULTICAST) == 0) { /* * Multicast packet is a idle packet and it's not TCP. */ /* 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) { mtx_enter(&pipex_list_mtx); /* update expire time */ if (session->state == PIPEX_STATE_OPENED) session->idle_time = 0; mtx_leave(&pipex_list_mtx); } } /* adjust tcpmss */ if ((session->ppp_flags & PIPEX_PPP_ADJUST_TCPMSS) != 0) { m0 = adjust_tcp_mss(m0, session->peer_mru); if (m0 == NULL) goto dropped; } pipex_ppp_output(m0, session, PPP_IP); } else { struct pipex_session *session_tmp; struct mbuf *m; m0->m_flags &= ~(M_BCAST|M_MCAST); mtx_enter(&pipex_list_mtx); session_tmp = LIST_FIRST(&pipex_session_list); while (session_tmp != NULL) { struct pipex_session *session_save = NULL; if (session_tmp->ownersc != session->ownersc) goto next; refcnt_take(&session_tmp->pxs_refcnt); mtx_leave(&pipex_list_mtx); m = m_copym(m0, 0, M_COPYALL, M_NOWAIT); if (m != NULL) pipex_ppp_output(m, session_tmp, PPP_IP); else counters_inc(session_tmp->stat_counters, pxc_oerrors); mtx_enter(&pipex_list_mtx); session_save = session_tmp; next: session_tmp = LIST_NEXT(session_tmp, session_list); if (session_save != NULL) pipex_rele_session(session_save); } mtx_leave(&pipex_list_mtx); m_freem(m0); } return; dropped: counters_inc(session->stat_counters, pxc_oerrors); } 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) { m0 = pipex_mppe_output(m0, session, PPP_IP); if (m0 == NULL) goto drop; proto = PPP_COMP; } } #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: mtx_enter(&session->pxs_mtx); pipex_pptp_output(m0, session, 1, 1); mtx_leave(&session->pxs_mtx); break; #endif #ifdef PIPEX_L2TP case PIPEX_PROTO_L2TP: pipex_l2tp_output(m0, session); break; #endif default: goto drop; } return; drop: m_freem(m0); counters_inc(session->stat_counters, pxc_oerrors); } void pipex_ppp_input(struct mbuf *m0, struct pipex_session *session, int decrypted) { int proto, hlen = 0; struct mbuf *n; #ifdef PIPEX_MPPE again: #endif 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); m0 = pipex_mppe_input(m0, session); if (m0 == NULL) goto drop; decrypted = 1; goto again; } if (proto == PPP_CCP) { if (decrypted) goto drop; #if NBPFILTER > 0 { struct ifnet *ifp; if ((ifp = if_get(session->ifindex)) != NULL) { if (ifp->if_bpf && ifp->if_type == IFT_PPP) bpf_mtap(ifp->if_bpf, m0, BPF_DIRECTION_IN); } if_put(ifp); } #endif m_adj(m0, hlen); pipex_ccp_input(m0, session); return; } #endif m_adj(m0, hlen); if (!ALIGNED_POINTER(mtod(m0, caddr_t), uint32_t)) { n = m_dup_pkt(m0, 0, M_NOWAIT); if (n == NULL) goto drop; m_freem(m0); m0 = n; } switch (proto) { case PPP_IP: if (!decrypted && pipex_session_is_mppe_required(session)) /* * if ip packet received when mppe * is required, discard it. */ goto drop; pipex_ip_input(m0, session); return; #ifdef INET6 case PPP_IPV6: if (!decrypted && pipex_session_is_mppe_required(session)) /* * if ip packet received when mppe * is required, discard it. */ goto drop; 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); counters_inc(session->stat_counters, pxc_ierrors); } void pipex_ip_input(struct mbuf *m0, struct pipex_session *session) { struct ifnet *ifp; struct ip *ip; int len; int is_idle; /* change recvif */ m0->m_pkthdr.ph_ifidx = session->ifindex; if (ISSET(session->ppp_flags, PIPEX_PPP_INGRESS_FILTER)) { PIPEX_PULLUP(m0, sizeof(struct ip)); if (m0 == NULL) goto drop; /* 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 */ mtx_enter(&pipex_list_mtx); if (session->state == PIPEX_STATE_OPENED) session->idle_time = 0; mtx_leave(&pipex_list_mtx); } } /* 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 ((ifp = if_get(session->ifindex)) == NULL) goto drop; #if NBPFILTER > 0 if (ifp->if_bpf) bpf_mtap_af(ifp->if_bpf, AF_INET, m0, BPF_DIRECTION_IN); #endif counters_pkt(ifp->if_counters, ifc_ipackets, ifc_ibytes, len); counters_pkt(session->stat_counters, pxc_ipackets, pxc_ibytes, len); ipv4_input(ifp, m0); if_put(ifp); return; drop: m_freem(m0); counters_inc(session->stat_counters, pxc_ierrors); } #ifdef INET6 void pipex_ip6_input(struct mbuf *m0, struct pipex_session *session) { struct ifnet *ifp; int len; /* change recvif */ m0->m_pkthdr.ph_ifidx = session->ifindex; /* * 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 ((ifp = if_get(session->ifindex)) == NULL) goto drop; #if NBPFILTER > 0 if (ifp->if_bpf) bpf_mtap_af(ifp->if_bpf, AF_INET6, m0, BPF_DIRECTION_IN); #endif counters_pkt(ifp->if_counters, ifc_ipackets, ifc_ibytes, len); counters_pkt(session->stat_counters, pxc_ipackets, pxc_ibytes, len); ipv6_input(ifp, m0); if_put(ifp); return; drop: m_freem(m0); counters_inc(session->stat_counters, pxc_ierrors); } #endif struct mbuf * pipex_common_input(struct pipex_session *session, struct mbuf *m0, int hlen, int plen, int locked) { int proto, ppphlen; u_char code; if ((m0->m_pkthdr.len < hlen + PIPEX_PPPMINLEN) || (plen < PIPEX_PPPMINLEN)) { if (locked) mtx_leave(&session->pxs_mtx); 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, &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; } if (locked) mtx_leave(&session->pxs_mtx); /* ok, The packet is for PIPEX */ m_adj(m0, hlen);/* cut off the tunnel 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); } pipex_ppp_input(m0, session, 0); return (NULL); drop: m_freem(m0); counters_inc(session->stat_counters, pxc_ierrors); return (NULL); not_ours: return (m0); /* Not to be handled by PIPEX */ } /* * pipex_ppp_proto */ 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 const 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), &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 if (session && session->proto.pppoe.over_ifidx != m0->m_pkthdr.ph_ifidx) { pipex_rele_session(session); session = NULL; } 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), &pppoe); hlen = sizeof(struct ether_header) + sizeof(struct pipex_pppoe_header); m0 = pipex_common_input(session, m0, hlen, ntohs(pppoe.length), 0); if (m0 == NULL) return (NULL); m_freem(m0); counters_inc(session->stat_counters, pxc_ierrors); return (NULL); } /* * pipex_ppope_output */ void pipex_pppoe_output(struct mbuf *m0, struct pipex_session *session) { struct pipex_pppoe_header *pppoe; int len, padlen; /* save length for pppoe header */ len = m0->m_pkthdr.len; /* 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__)); counters_inc(session->stat_counters, pxc_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 = session->proto.pppoe.over_ifidx; refcnt_take(&session->pxs_refcnt); m0->m_pkthdr.ph_cookie = session; m0->m_flags &= ~(M_BCAST|M_MCAST); if (mq_enqueue(&pipexoutq, m0) != 0) { counters_inc(session->stat_counters, pxc_oerrors); pipex_rele_session(session); } else schednetisr(NETISR_PIPEX); } #endif /* PIPEX_PPPOE */ #ifdef PIPEX_PPTP /*********************************************************************** * PPTP ***********************************************************************/ 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; MUTEX_ASSERT_LOCKED(&session->pxs_mtx); 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->ifindex; ip_send(m0); if (len > 0) { /* network layer only */ /* countup statistics */ counters_pkt(session->stat_counters, pxc_opackets, pxc_obytes, len); } return; drop: counters_inc(session->stat_counters, pxc_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), &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), &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); } mtx_enter(&session->pxs_mtx); 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); } /* * The following pipex_common_input() will release `pxs_mtx' * deep within if the packet will be consumed. In the error * path lock will be held all the time. So increment `rcv_gap' * here, and on the error path back it out, no atomicity will * be lost in all cases. */ if (!rewind) session->proto.pptp.rcv_gap += nseq; m0 = pipex_common_input(session, m0, hlen, ntohs(gre->len), 1); if (m0 == NULL) { /* * pipex_common_input() releases lock if the * packet was consumed. */ return (NULL); } if (rewind) goto out_seq; else { /* The packet is not ours, back out `rcv_gap'. */ session->proto.pptp.rcv_gap -= nseq; } 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); } mtx_leave(&session->pxs_mtx); 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); mtx_leave(&session->pxs_mtx); /* FALLTHROUGH */ drop: m_freem(m0); counters_inc(session->stat_counters, pxc_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 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), &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); mtx_enter(&pipex_list_mtx); list = PIPEX_PEER_ADDR_HASHTABLE(pipex_sockaddr_hash_key(sa)); LIST_FOREACH(session, list, peer_addr_chain) { if (pipex_sockaddr_compar_addr(&session->peer.sa, sa) != 0) continue; if (session->peer_session_id == id) break; } if (session != NULL) refcnt_take(&session->pxs_refcnt); mtx_leave(&pipex_list_mtx); #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, &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 *); mtx_enter(&session->pxs_mtx); /* * 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; } mtx_leave(&session->pxs_mtx); return (m0); } #endif /* PIPEX_PPTP */ #ifdef PIPEX_L2TP /*********************************************************************** * L2TP support ***********************************************************************/ 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 struct m_tag *mtag; 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; mtx_enter(&session->pxs_mtx); 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); mtx_leave(&session->pxs_mtx); } 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->ifindex; #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; mtx_enter(&session->pxs_mtx); if (session->proto.l2tp.ipsecflowinfo > 0) { if ((mtag = m_tag_get(PACKET_TAG_IPSEC_FLOWINFO, sizeof(u_int32_t), M_NOWAIT)) == NULL) { mtx_leave(&session->pxs_mtx); goto drop; } *(u_int32_t *)(mtag + 1) = session->proto.l2tp.ipsecflowinfo; m_tag_prepend(m0, mtag); } mtx_leave(&session->pxs_mtx); ip_send(m0); 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. */ ip6_send(m0); break; #endif } udpstat_inc(udps_opackets); if (datalen > 0) { /* network layer only */ /* countup statistics */ counters_pkt(session->stat_counters, pxc_opackets, pxc_obytes, datalen); } return; drop: m_freem(m0); counters_inc(session->stat_counters, pxc_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 = 0, offset = 0, hlen, nseq; u_char *cp, *nsp = NULL, *nrp = NULL; uint16_t flags, ns = 0, nr = 0; int rewind = 0; mtx_enter(&session->pxs_mtx); l2tp_session = &session->proto.l2tp; l2tp_session->ipsecflowinfo = ipsecflowinfo; m_copydata(m0, off0, sizeof(flags), &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; /* * The following pipex_common_input() will release `pxs_mtx' * deep within if the packet will be consumed. In the error * path lock will be held all the time. So increment `nr_gap' * here, and on the error path back it out, no atomicity will * be lost in all cases. */ if (!rewind) session->proto.l2tp.nr_gap += nseq; m0 = pipex_common_input(session, m0, hlen, length, 1); if (m0 == NULL) { /* * pipex_common_input() releases lock if the * packet was consumed. */ return (NULL); } if (rewind) goto out_seq; else { /* The packet is not ours, backout `nr_gap'. */ session->proto.l2tp.nr_gap -= nseq; } /* * 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); } mtx_leave(&session->pxs_mtx); 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: mtx_leave(&session->pxs_mtx); m_freem(m0); counters_inc(session->stat_counters, pxc_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), &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); mtx_enter(&pipex_list_mtx); list = PIPEX_PEER_ADDR_HASHTABLE(pipex_sockaddr_hash_key(sa)); LIST_FOREACH(session, list, peer_addr_chain) { if (pipex_sockaddr_compar_addr(&session->peer.sa, sa) != 0) continue; if (session->proto.l2tp.peer_tunnel_id != tunnel_id) continue; if (session->peer_session_id == session_id) break; } if (session != NULL) refcnt_take(&session->pxs_refcnt); mtx_leave(&pipex_list_mtx); #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); mtx_enter(&session->pxs_mtx); 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; mtx_leave(&session->pxs_mtx); return (m0); } #endif /* PIPEX_L2TP */ #ifdef PIPEX_MPPE /********************************************************************** * MPPE ***********************************************************************/ #define PIPEX_COHERENCY_CNT_MASK 0x0fff 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); } 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)); mtx_init(&mppe->pxm_mtx, IPL_SOFTNET); if (stateless) mppe->flags |= PIPEX_MPPE_STATELESS; 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, }; 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); } void pipex_mppe_reduce_key(struct pipex_mppe *mppe) { switch (mppe->keylenbits) { case 40: mppe->session_key[0] = 0xd1; mppe->session_key[1] = 0x26; mppe->session_key[2] = 0x9e; break; case 56: mppe->session_key[0] = 0xd1; break; } } 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); } } struct mbuf * 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; mtx_enter(&mppe->pxm_mtx); PIPEX_MPPE_DBG((session, LOG_DEBUG, "in coher_cnt=%03x %s%s", mppe->coher_cnt, (flushed) ? "[flushed]" : "", (encrypt) ? "[encrypt]" : "")); if (encrypt == 0) { mtx_leave(&mppe->pxm_mtx); 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->flags & PIPEX_MPPE_STATELESS) == 0 || 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); mtx_leave(&mppe->pxm_mtx); goto drop; } rewind = 1; } } if ((mppe->flags & PIPEX_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) { int ccp_id; mtx_leave(&mppe->pxm_mtx); /* Send CCP ResetReq */ PIPEX_DBG((session, LOG_DEBUG, "CCP SendResetReq")); mtx_enter(&session->pxs_mtx); ccp_id = session->ccp_id; session->ccp_id++; mtx_leave(&session->pxs_mtx); pipex_ccp_output(session, CCP_RESETREQ, 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; } mtx_leave(&mppe->pxm_mtx); if (m0->m_pkthdr.len < PIPEX_PPPMINLEN) goto drop; return (m0); drop: m_freem(m0); return (NULL); } struct mbuf * 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 retransmission. */ 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) return (NULL); m0 = m; break; } } /* prepend mppe header */ M_PREPEND(m0, sizeof(struct mppe_header), M_NOWAIT); if (m0 == NULL) return (NULL); hdr = mtod(m0, struct mppe_header *); hdr->protocol = protocol; /* check coherency counter */ flushed = 0; encrypt = 1; mtx_enter(&mppe->pxm_mtx); if ((mppe->flags & PIPEX_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->flags & PIPEX_MPPE_RESETREQ) != 0) { flushed = 1; mppe->flags &= ~PIPEX_MPPE_RESETREQ; } } 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); } mtx_leave(&mppe->pxm_mtx); return (m0); } 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")); mtx_enter(&session->mppe_send.pxm_mtx); session->mppe_send.flags |= PIPEX_MPPE_RESETREQ; mtx_leave(&session->mppe_send.pxm_mtx); #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); counters_inc(session->stat_counters, pxc_ierrors); } 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) { counters_inc(session->stat_counters, pxc_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 functions ***********************************************************************/ /* 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. */ 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) */ 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); } void pipex_session_log(struct pipex_session *session, int prio, const char *fmt, ...) { char logbuf[1024]; va_list ap; logpri(prio); if (session != NULL) { struct ifnet *ifp; ifp = if_get(session->ifindex); addlog("pipex: ppp=%d iface=%s protocol=%s id=%d ", session->ppp_id, ifp? ifp->if_xname : "Unknown", (session->protocol == PIPEX_PROTO_PPPOE)? "PPPoE" : (session->protocol == PIPEX_PROTO_PPTP)? "PPTP" : (session->protocol == PIPEX_PROTO_L2TP) ? "L2TP" : "Unknown", session->session_id); if_put(ifp); } else addlog("pipex: "); va_start(ap, fmt); vsnprintf(logbuf, sizeof(logbuf), fmt, ap); va_end(ap); addlog("%s\n", logbuf); } 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. */ 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); } 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_bounded(oldp, oldlenp, newp, newlen, &pipex_enable, 0, 1)); default: return (ENOPROTOOPT); } /* NOTREACHED */ }