/* $OpenBSD: l2tp_call.c,v 1.20 2021/03/29 03:54:39 yasuoka 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. */ /* $Id: l2tp_call.c,v 1.20 2021/03/29 03:54:39 yasuoka Exp $ */ /**@file L2TP LNS call */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "debugutil.h" #include "bytebuf.h" #include "hash.h" #include "slist.h" #include "l2tp.h" #include "l2tp_subr.h" #include "npppd.h" #include "l2tp_local.h" #ifdef L2TP_CALL_DEBUG #define L2TP_CALL_DBG(m) l2tp_call_log m #define L2TP_CALL_ASSERT(x) ASSERT(x) #else #define L2TP_CALL_DBG(m) #define L2TP_CALL_ASSERT(x) #endif static void l2tp_call_log (l2tp_call *, int, const char *, ...) __printflike(3,4); static void l2tp_call_disconnect (l2tp_call *, int, int, const char *, struct l2tp_avp *[], int); static int l2tp_call_recv_ICRQ (l2tp_call *, u_char *, int); static int l2tp_call_send_ICRP (l2tp_call *); static int l2tp_call_recv_ICCN (l2tp_call *, u_char *, int, dialin_proxy_info *); static int l2tp_recv_CDN (l2tp_call *, u_char *, int); static int l2tp_call_send_CDN (l2tp_call *, int, int, const char *, struct l2tp_avp *[], int); static int l2tp_call_send_ZLB (l2tp_call *); static inline const char *l2tp_call_state_string (l2tp_call *); static int l2tp_call_bind_ppp (l2tp_call *, dialin_proxy_info *); static void l2tp_call_notify_down (l2tp_call *); static int l2tp_call_send_data_packet (l2tp_call *, bytebuffer *); static int l2tp_call_ppp_output (npppd_ppp *, unsigned char *, int, int); static void l2tp_call_closed_by_ppp (npppd_ppp *); /* create {@link ::_l2tp_call L2TP call} instance */ l2tp_call * l2tp_call_create(void) { l2tp_call *_this; if ((_this = malloc(sizeof(l2tp_call))) == NULL) return NULL; return _this; } /* initialize {@link ::_l2tp_call L2TP call} instance */ int l2tp_call_init(l2tp_call *_this, l2tp_ctrl *ctrl) { memset(_this, 0, sizeof(l2tp_call)); _this->ctrl = ctrl; if (l2tpd_assign_call(ctrl->l2tpd, _this) != 0) return -1; _this->use_seq = ctrl->data_use_seq; return 0; } /* free {@link ::_l2tp_call L2TP call} instance */ void l2tp_call_destroy(l2tp_call *_this, int from_l2tp_ctrl) { l2tpd_release_call(_this->ctrl->l2tpd, _this); free(_this); } /* * l2tp disconnect will occur when * 1) disconnect request issued from nppdctl command * 2) npppd is terminated * in case 1) ppp_stop() is used to terminal. (PPP LCP TermReq) * and in case 2) l2tp_call_disconnect() is used (L2TP CDN) */ /* administrative reason disconnection */ void l2tp_call_admin_disconnect(l2tp_call *_this) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ADMINISTRATIVE_REASON, 0, NULL, NULL, 0); } void l2tp_call_drop(l2tp_call *_this) { l2tp_call_disconnect(_this, 0, 0, NULL, NULL, 0); } /* * disconnect l2tp connection * @param result_code disconnect without CDN, specify zero */ static void l2tp_call_disconnect(l2tp_call *_this, int result_code, int error_code, const char *errmes, struct l2tp_avp *addavp[], int naddavp) { L2TP_CALL_ASSERT(_this != NULL); if (_this->state == L2TP_CALL_STATE_CLEANUP_WAIT) { /* CDN received, or have been sent */ l2tp_call_notify_down(_this); /* just in case */ return; } if (result_code > 0) { if (l2tp_call_send_CDN(_this, result_code, error_code, errmes, addavp, naddavp) != 0) l2tp_call_log(_this, LOG_ERR, "Error sending CDN: %m"); } _this->state = L2TP_CALL_STATE_CLEANUP_WAIT; l2tp_call_notify_down(_this); } /* * control packet */ /* call it when control packet is received */ int l2tp_call_recv_packet(l2tp_ctrl *ctrl, l2tp_call *_this, int mestype, u_char *pkt, int pktlen) { int i, len, session_id, send_cdn; l2tp_call *call; dialin_proxy_info dpi; /* when ICRQ, this will be NULL */ L2TP_CALL_ASSERT(_this != NULL || mestype == L2TP_AVP_MESSAGE_TYPE_ICRQ); if (_this == NULL) { if (mestype != L2TP_AVP_MESSAGE_TYPE_ICRQ) return 1; if ((_this = l2tp_call_create()) == NULL) { l2tp_ctrl_log(ctrl, LOG_ERR, "l2tp_call_create failed in %s(): %m", __func__); return 1; } l2tp_call_init(_this, ctrl); if (l2tp_call_recv_ICRQ(_this, pkt, pktlen) != 0) return 1; len = slist_length(&ctrl->call_list); session_id = _this->id; again: /* assign a session ID */ session_id &= 0xffff; if (session_id == 0) session_id = 1; for (i = 0; i < len; i++) { call = slist_get(&ctrl->call_list, i); if (call->session_id == session_id) { session_id++; goto again; } } _this->session_id = session_id; /* add the l2tp_call to call list */ slist_add(&_this->ctrl->call_list, _this); if (l2tp_call_send_ICRP(_this) != 0) return 1; _this->state = L2TP_CALL_STATE_WAIT_CONN; return 0; } /* state machine */ send_cdn = 0; switch (_this->state) { default: break; case L2TP_CALL_STATE_WAIT_CONN: switch (mestype) { case L2TP_AVP_MESSAGE_TYPE_ICCN: memset(&dpi, 0, sizeof(dpi)); if (l2tp_call_recv_ICCN(_this, pkt, pktlen, &dpi) != 0) return 1; l2tp_call_bind_ppp(_this, &dpi); l2tp_call_send_ZLB(_this); _this->state = L2TP_CALL_STATE_ESTABLISHED; _this->ctrl->ncalls++; return 0; case L2TP_AVP_MESSAGE_TYPE_ICRQ: case L2TP_AVP_MESSAGE_TYPE_ICRP: send_cdn = 1; /* FALLTHROUGH */ default: l2tp_call_log(_this, LOG_ERR, "Waiting ICCN. But received %s", avp_mes_type_string(mestype)); if (send_cdn) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_GENERIC_ERROR, "Illegal state.", NULL, 0); return 0; } } break; case L2TP_CALL_STATE_ESTABLISHED: switch (mestype) { case L2TP_AVP_MESSAGE_TYPE_CDN: /* disconnect from peer. log it */ l2tp_recv_CDN(_this, pkt, pktlen); _this->state = L2TP_CALL_STATE_CLEANUP_WAIT; l2tp_call_notify_down(_this); l2tp_call_send_ZLB(_this); return 0; case L2TP_AVP_MESSAGE_TYPE_ICRQ: case L2TP_AVP_MESSAGE_TYPE_ICRP: case L2TP_AVP_MESSAGE_TYPE_ICCN: send_cdn = 1; break; default: break; } l2tp_call_log(_this, LOG_ERR, "Call established. But received %s", avp_mes_type_string(mestype)); if (send_cdn) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_GENERIC_ERROR, "Illegal state.", NULL, 0); return 0; } l2tp_call_disconnect(_this, 0, 0, NULL, NULL, 0); return 1; } l2tp_call_log(_this, LOG_INFO, "Received %s in unexpected state=%s", avp_mes_type_string(mestype), l2tp_call_state_string(_this)); l2tp_call_disconnect(_this, 0, 0, NULL, NULL, 0); return 1; } /* * receive ICRQ * @return return 0 if the ICRQ is acceptable. * other values means fail to receive, and * CDN was sent and status was updated. */ static int l2tp_call_recv_ICRQ(l2tp_call *_this, u_char *pkt, int pktlen) { int avpsz, slen; struct l2tp_avp *avp; char buf[L2TP_AVP_MAXSIZ], emes[256]; avp = (struct l2tp_avp *)buf; while (pktlen >= 6 && (avpsz = avp_enum(avp, pkt, pktlen, 1)) > 0) { pkt += avpsz; pktlen -= avpsz; if (avp->vendor_id != 0) { L2TP_CALL_DBG((_this, LOG_DEBUG, "Received a Vendor-specific AVP vendor-id=%d " "type=%d", avp->vendor_id, avp->attr_type)); continue; } if (avp->is_hidden != 0) { l2tp_call_log(_this, LOG_WARNING, "Received AVP (%s/%d) is hidden. But we don't " "share secret.", avp_attr_type_string(avp->attr_type), avp->attr_type); if (avp->is_mandatory != 0) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; } continue; } switch (avp->attr_type) { case L2TP_AVP_TYPE_MESSAGE_TYPE: AVP_SIZE_CHECK(avp, ==, 8); continue; case L2TP_AVP_TYPE_ASSIGNED_SESSION_ID: AVP_SIZE_CHECK(avp, ==, 8); _this->peer_session_id = avp_get_val16(avp); continue; case L2TP_AVP_TYPE_CALL_SERIAL_NUMBER: case L2TP_AVP_TYPE_BEARER_TYPE: case L2TP_AVP_TYPE_PHYSICAL_CHANNEL_ID: /* * Memo: * Microsoft "L2TP/IPsec VPN Client" for * Windows 98/Me/NT asserts mandatory bit in * Physical Channel Id */ break; case L2TP_AVP_TYPE_CALLING_NUMBER: slen = MINIMUM(sizeof(_this->calling_number) - 1, avp_attr_length(avp)); memcpy(_this->calling_number, avp->attr_value, slen); _this->calling_number[slen] = '\0'; break; case L2TP_AVP_TYPE_CALLED_NUMBER: case L2TP_AVP_TYPE_SUB_ADDRESS: continue; default: if (avp->is_mandatory) { l2tp_call_log(_this, LOG_WARNING, "AVP (%s/%d) is not supported, but it's " "mandatory", avp_attr_type_string(avp->attr_type), avp->attr_type); if (avp->is_mandatory != 0) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; } #ifdef L2TP_CALL_DEBUG } else { L2TP_CALL_DBG((_this, LOG_DEBUG, "AVP (%s/%d) is not handled", avp_attr_type_string(avp->attr_type), avp->attr_type)); #endif } } } if (_this->peer_session_id == 0) { l2tp_call_log(_this, LOG_ERR, "Received a bad ICRP: SessionId = 0"); l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_INVALID_MESSAGE, "Session Id must not be 0", NULL, 0); return 1; } l2tp_call_log(_this, LOG_INFO, "RecvICRQ session_id=%u", _this->peer_session_id); return 0; size_check_failed: l2tp_call_log(_this, LOG_ERR, "Received bad ICRQ: %s", emes); l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_WRONG_LENGTH, NULL, NULL, 0); return 1; } /* send ICRP */ static int l2tp_call_send_ICRP(l2tp_call *_this) { int rval; struct l2tp_avp *avp; char buf[L2TP_AVP_MAXSIZ]; bytebuffer *bytebuf; bytebuf = l2tp_ctrl_prepare_snd_buffer(_this->ctrl, 1); if (bytebuf == NULL) { l2tp_call_log(_this, LOG_ERR, "sending ICRP failed: no buffer"); return 1; } avp = (struct l2tp_avp *)buf; /* Message Type = ICRP */ memset(avp, 0, sizeof(*avp)); avp->is_mandatory = 1; avp->attr_type = L2TP_AVP_TYPE_MESSAGE_TYPE; avp_set_val16(avp, L2TP_AVP_MESSAGE_TYPE_ICRP); bytebuf_add_avp(bytebuf, avp, 2); memset(avp, 0, sizeof(*avp)); avp->is_mandatory = 1; avp->attr_type = L2TP_AVP_TYPE_ASSIGNED_SESSION_ID; avp_set_val16(avp, _this->session_id); bytebuf_add_avp(bytebuf, avp, 2); if ((rval = l2tp_ctrl_send_packet(_this->ctrl, _this->peer_session_id, bytebuf)) != 0) { l2tp_call_log(_this, LOG_ERR, "failed to SendICRP: %m"); return 1; } l2tp_call_log(_this, LOG_INFO, "SendICRP session_id=%u", _this->session_id); return 0; } /* send L2TP data message */ static int l2tp_call_send_data_packet(l2tp_call *_this, bytebuffer *buffer) { int rval; struct l2tp_header *hdr; bytebuffer_flip(buffer); hdr = (struct l2tp_header *)bytebuffer_pointer(buffer); memset(hdr, 0, sizeof(*hdr) - 4); /* Nr, NS are option */ hdr->t = 0; hdr->ver = L2TP_HEADER_VERSION_RFC2661; hdr->l = 1; hdr->length = htons(bytebuffer_remaining(buffer)); hdr->tunnel_id = htons(_this->ctrl->peer_tunnel_id); hdr->session_id = htons(_this->peer_session_id); if (_this->use_seq) { hdr->s = 1; hdr->ns = htons(_this->snd_nxt++); hdr->nr = htons(_this->rcv_nxt); } if (L2TP_CTRL_CONF(_this->ctrl)->data_out_pktdump != 0) { l2tpd_log(_this->ctrl->l2tpd, LOG_DEBUG, "ctrl=%u call=%u L2TP Data output packet dump", _this->ctrl->id, _this->id); show_hd(debug_get_debugfp(), bytebuffer_pointer(buffer), bytebuffer_remaining(buffer)); } if ((rval = l2tp_ctrl_send(_this->ctrl, bytebuffer_pointer(buffer), bytebuffer_remaining(buffer))) < 0) { L2TP_CALL_DBG((_this, LOG_DEBUG, "sendto() failed: %m")); } return (rval == bytebuffer_remaining(buffer))? 0 : 1; } /* * receive ICCN * @return return 0 if the ICCN is acceptable. * other value means fail to receive, and * CDN was sent and status was updated. */ static int l2tp_call_recv_ICCN(l2tp_call *_this, u_char *pkt, int pktlen, dialin_proxy_info *dpi) { int avpsz, tx_conn_speed; uint32_t framing_type = 0; struct l2tp_avp *avp; char buf[L2TP_AVP_MAXSIZ], emes[256]; tx_conn_speed = 0; avp = (struct l2tp_avp *)buf; while (pktlen >= 6 && (avpsz = avp_enum(avp, pkt, pktlen, 1)) > 0) { pkt += avpsz; pktlen -= avpsz; if (avp->vendor_id != 0) { L2TP_CALL_DBG((_this, LOG_DEBUG, "Received a Vendor-specific AVP vendor-id=%d " "type=%d", avp->vendor_id, avp->attr_type)); continue; } if (avp->is_hidden != 0) { l2tp_call_log(_this, LOG_WARNING, "Received AVP (%s/%d) is hidden. But we don't " "share secret.", avp_attr_type_string(avp->attr_type), avp->attr_type); if (avp->is_mandatory != 0) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; } continue; } switch (avp->attr_type) { case L2TP_AVP_TYPE_MESSAGE_TYPE: AVP_SIZE_CHECK(avp, ==, 8); continue; case L2TP_AVP_TYPE_RX_CONNECT_SPEED: /* * As RFC 2661 this AVP is not mandatory. But `xl2tpd' * sends this as a mandatory AVP. Handle this to * ignore the xl2tpd' bug. */ AVP_SIZE_CHECK(avp, ==, 10); continue; case L2TP_AVP_TYPE_TX_CONNECT_SPEED: AVP_SIZE_CHECK(avp, ==, 10); tx_conn_speed = avp_get_val32(avp); continue; case L2TP_AVP_TYPE_FRAMING_TYPE: AVP_SIZE_CHECK(avp, ==, 10); framing_type = avp_get_val32(avp); continue; case L2TP_AVP_TYPE_SEQUENCING_REQUIRED: _this->seq_required = 1; _this->use_seq = 1; continue; /* * AVP's for Proxy-LCP and Proxy-Authen */ case L2TP_AVP_TYPE_LAST_SENT_LCP_CONFREQ: AVP_MAXLEN_CHECK(avp, sizeof(dpi->last_sent_lcp.data)); memcpy(dpi->last_sent_lcp.data, avp->attr_value, avp_attr_length(avp)); dpi->last_sent_lcp.ldata = avp_attr_length(avp); break; case L2TP_AVP_TYPE_LAST_RECV_LCP_CONFREQ: AVP_MAXLEN_CHECK(avp, sizeof(dpi->last_recv_lcp.data)); memcpy(dpi->last_recv_lcp.data, avp->attr_value, avp_attr_length(avp)); dpi->last_recv_lcp.ldata = avp_attr_length(avp); break; case L2TP_AVP_TYPE_PROXY_AUTHEN_CHALLENGE: AVP_MAXLEN_CHECK(avp, sizeof(dpi->auth_chall)); memcpy(dpi->auth_chall, avp->attr_value, avp_attr_length(avp)); dpi->lauth_chall = avp_attr_length(avp); break; case L2TP_AVP_TYPE_PROXY_AUTHEN_ID: AVP_SIZE_CHECK(avp, ==, 8); dpi->auth_id = avp_get_val16(avp); break; case L2TP_AVP_TYPE_PROXY_AUTHEN_NAME: AVP_MAXLEN_CHECK(avp, sizeof(dpi->username) - 1); memcpy(dpi->username, avp->attr_value, avp_attr_length(avp)); break; case L2TP_AVP_TYPE_PROXY_AUTHEN_RESPONSE: AVP_MAXLEN_CHECK(avp, sizeof(dpi->auth_resp)); memcpy(dpi->auth_resp, avp->attr_value, avp_attr_length(avp)); dpi->lauth_resp = avp_attr_length(avp); break; case L2TP_AVP_TYPE_PROXY_AUTHEN_TYPE: AVP_SIZE_CHECK(avp, ==, 8); switch (avp_get_val16(avp)) { default: l2tp_call_log(_this, LOG_WARNING, "RecvICCN Unknown proxy-authen-type=%d", avp_get_val16(avp)); /* FALLTHROUGH */ case L2TP_AUTH_TYPE_NO_AUTH: dpi->auth_type = 0; break; case L2TP_AUTH_TYPE_PPP_CHAP: dpi->auth_type = PPP_AUTH_CHAP_MD5; break; case L2TP_AUTH_TYPE_PPP_PAP: dpi->auth_type = PPP_AUTH_PAP; break; case L2TP_AUTH_TYPE_MS_CHAP_V1: dpi->auth_type = PPP_AUTH_CHAP_MS; break; } break; default: if (avp->is_mandatory != 0) { l2tp_call_log(_this, LOG_WARNING, "AVP (%s/%d) is not supported, but it's " "mandatory", avp_attr_type_string(avp->attr_type), avp->attr_type); l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; #ifdef L2TP_CALL_DEBUG } else { L2TP_CALL_DBG((_this, LOG_DEBUG, "AVP (%s/%d) is not handled", avp_attr_type_string(avp->attr_type), avp->attr_type)); #endif } } } l2tp_call_log(_this, LOG_INFO, "RecvICCN " "session_id=%u calling_number=%s tx_conn_speed=%u framing=%s", _this->peer_session_id, _this->calling_number, tx_conn_speed, ((framing_type & L2TP_FRAMING_CAP_FLAGS_ASYNC) != 0)? "async" : ((framing_type & L2TP_FRAMING_CAP_FLAGS_SYNC) != 0)? "sync" : "unknown"); return 0; size_check_failed: l2tp_call_log(_this, LOG_ERR, "Received bad ICCN: %s", emes); l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_WRONG_LENGTH, NULL, NULL, 0); return 1; } /* receive CDN */ static int l2tp_recv_CDN(l2tp_call *_this, u_char *pkt, int pktlen) { int result, error, avpsz, len, sessid; struct l2tp_avp *avp; char buf[L2TP_AVP_MAXSIZ], emes[256], pmes[256]; /* initialize */ result = 0; error = 0; sessid = 0; strlcpy(pmes, "(none)", sizeof(pmes)); avp = (struct l2tp_avp *)buf; while (pktlen >= 6 && (avpsz = avp_enum(avp, pkt, pktlen, 1)) > 0) { pkt += avpsz; pktlen -= avpsz; if (avp->vendor_id != 0) { L2TP_CALL_DBG((_this, LOG_DEBUG, "Received a Vendor-specific AVP vendor-id=%d " "type=%d", avp->vendor_id, avp->attr_type)); continue; } if (avp->is_hidden != 0) { l2tp_call_log(_this, LOG_WARNING, "Received AVP (%s/%d) is hidden. But we don't " "share secret.", avp_attr_type_string(avp->attr_type), avp->attr_type); if (avp->is_mandatory != 0) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; } continue; } switch (avp->attr_type) { case L2TP_AVP_TYPE_MESSAGE_TYPE: AVP_SIZE_CHECK(avp, ==, 8); continue; case L2TP_AVP_TYPE_RESULT_CODE: AVP_SIZE_CHECK(avp, >=, 8); result = avp->attr_value[0] << 8 | avp->attr_value[1]; if (avp->length >= 10) { error = avp->attr_value[2] << 8 | avp->attr_value[3]; len = avp->length - 12; if (len > 0) { len = MINIMUM(len, sizeof(pmes) - 1); memcpy(pmes, &avp->attr_value[4], len); pmes[len] = '\0'; } } continue; case L2TP_AVP_TYPE_ASSIGNED_SESSION_ID: AVP_SIZE_CHECK(avp, >=, 8); sessid = avp_get_val16(avp); continue; default: if (avp->is_mandatory) { l2tp_call_log(_this, LOG_WARNING, "AVP (%s/%d) is not supported, but it's " "mandatory", avp_attr_type_string(avp->attr_type), avp->attr_type); if (avp->is_mandatory != 0) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_UNKNOWN_MANDATORY_AVP, NULL, NULL, 0); return 1; } #ifdef L2TP_CALL_DEBUG } else { L2TP_CALL_DBG((_this, LOG_DEBUG, "AVP (%s/%d) is not handled", avp_attr_type_string(avp->attr_type), avp->attr_type)); #endif } } } if (error == 0) { l2tp_call_log(_this, LOG_INFO, "RecvCDN result=%s/%d", l2tp_cdn_rcode_string(result), result); } else { l2tp_call_log(_this, LOG_INFO, "RecvCDN result=%s/%d error=%s/%d message=%s", l2tp_cdn_rcode_string(result), result, l2tp_ecode_string(error), error, pmes); } return 0; size_check_failed: /* continue to process even if the CDN message was broken */ l2tp_call_log(_this, LOG_ERR, "Received bad CDN: %s", emes); return 0; } /* send CDN */ static int l2tp_call_send_CDN(l2tp_call *_this, int result_code, int error_code, const char *errmes, struct l2tp_avp *addavp[], int naddavp) { uint32_t val32; int i, avplen, len; struct l2tp_avp *avp; char buf[L2TP_AVP_MAXSIZ]; bytebuffer *bytebuf; L2TP_CALL_ASSERT(_this != NULL); bytebuf = l2tp_ctrl_prepare_snd_buffer(_this->ctrl, 1); if (bytebuf == NULL) { l2tp_call_log(_this, LOG_ERR, "sending CDN failed: no buffer"); return 1; } avp = (struct l2tp_avp *)buf; /* Message Type = CDN */ memset(avp, 0, sizeof(*avp)); avp->is_mandatory = 1; avp->attr_type = L2TP_AVP_TYPE_MESSAGE_TYPE; avp_set_val16(avp, L2TP_AVP_MESSAGE_TYPE_CDN); bytebuf_add_avp(bytebuf, avp, 2); /* Result Code */ memset(avp, 0, sizeof(*avp)); avp->is_mandatory = 1; avp->attr_type = L2TP_AVP_TYPE_RESULT_CODE; #if 0 /* * Windows 2000 work around: * Windows 2000 will return "2 - Length is wrong" in StopCCN, * when it received "length = 8 and no error code AVP". * Avoid the error, use AVP length = 10. */ if (error_code > 0) { val32 = (result_code << 16) | (error_code & 0xffff); avplen = 4; avp_set_val32(avp, val32); } else { avplen = 2; avp_set_val16(avp, result_code); } #else val32 = (result_code << 16) | (error_code & 0xffff); avplen = 4; avp_set_val32(avp, val32); #endif if (errmes != NULL) { len = MINIMUM(strlen(errmes), L2TP_AVP_MAXSIZ - 128); memcpy(&avp->attr_value[avplen], errmes, len); avplen += len; } bytebuf_add_avp(bytebuf, avp, avplen); /* Assigned Session Id */ memset(avp, 0, sizeof(*avp)); avp->is_mandatory = 1; avp->attr_type = L2TP_AVP_TYPE_ASSIGNED_SESSION_ID; if (_this != NULL && _this->session_id != 0) avp_set_val16(avp, _this->session_id); else avp_set_val16(avp, 0); bytebuf_add_avp(bytebuf, avp, 2); for (i = 0; i < naddavp; i++) bytebuf_add_avp(bytebuf, addavp[i], addavp[i]->length - 6); if (l2tp_ctrl_send_packet(_this->ctrl, _this->peer_session_id, bytebuf) != 0) { l2tp_call_log(_this, LOG_ERR, "Error sending CDN: %m"); return 1; } if (error_code > 0) { l2tp_call_log(_this, LOG_INFO, "SendCDN result=%s/%d error=%s/%d message=%s", l2tp_cdn_rcode_string(result_code), result_code, l2tp_ecode_string(error_code), error_code, (errmes == NULL)? "none" : errmes); } else { l2tp_call_log(_this, LOG_INFO, "SendCDN result=%s/%d", l2tp_cdn_rcode_string(result_code), result_code); } return 0; } /* send ZLB */ static int l2tp_call_send_ZLB(l2tp_call *_this) { bytebuffer *bytebuf; l2tp_call_log(_this, LOG_INFO, "SendZLB"); bytebuf = l2tp_ctrl_prepare_snd_buffer(_this->ctrl, 1); if (bytebuf == NULL) { l2tp_call_log(_this, LOG_ERR, "sending ZLB failed: no buffer"); return 1; } return l2tp_ctrl_send_packet(_this->ctrl, _this->peer_session_id, bytebuf); } /* * misc */ /* logging with the label of the instance */ static void l2tp_call_log(l2tp_call *_this, int prio, const char *fmt, ...) { char logbuf[BUFSIZ]; va_list ap; va_start(ap, fmt); #ifdef L2TPD_MULTIPLE snprintf(logbuf, sizeof(logbuf), "l2tpd id=%u ctrl=%u call=%u %s", _this->ctrl->l2tpd->id, _this->ctrl->id, _this->id, fmt); #else snprintf(logbuf, sizeof(logbuf), "l2tpd ctrl=%u call=%u %s", _this->ctrl->id, _this->id, fmt); #endif vlog_printf(prio, logbuf, ap); va_end(ap); } /* convert current status to strings */ static inline const char * l2tp_call_state_string(l2tp_call *_this) { switch (_this->state) { case L2TP_CALL_STATE_IDLE: return "idle"; case L2TP_CALL_STATE_WAIT_CONN: return "wait-conn"; case L2TP_CALL_STATE_ESTABLISHED: return "established"; case L2TP_CALL_STATE_CLEANUP_WAIT: return "cleanup-wait"; } return "unknown"; } /* * npppd physical layer */ /* input packet to ppp */ void l2tp_call_ppp_input(l2tp_call *_this, u_char *pkt, int pktlen, int delayed) { int rval; npppd_ppp *ppp; ppp = _this->ppp; rval = ppp->recv_packet(ppp, pkt, pktlen, delayed ? PPP_IO_FLAGS_DELAYED : 0); if (_this->ppp == NULL) /* ppp is freed */ return; if (rval != 0) ppp->ierrors++; else { ppp->ipackets++; ppp->ibytes += pktlen; } } /* called ppp output a packet */ static int l2tp_call_ppp_output(npppd_ppp *ppp, unsigned char *bytes, int nbytes, int flags) { l2tp_call *_this; bytebuffer *bytebuf; _this = ppp->phy_context; bytebuf = l2tp_ctrl_prepare_snd_buffer(_this->ctrl, _this->use_seq); if (bytebuf != NULL) { bytebuffer_put(bytebuf, bytes, nbytes); if (l2tp_call_send_data_packet(_this, bytebuf) != 0) ppp->oerrors++; else { ppp->opackets++; ppp->obytes += nbytes; } } else ppp->oerrors++; return 0; } /* it will be called when the connection was closed at ppp */ static void l2tp_call_closed_by_ppp(npppd_ppp *ppp) { l2tp_call *_this; L2TP_CALL_ASSERT(ppp != NULL); L2TP_CALL_ASSERT(ppp->phy_context != NULL); _this = ppp->phy_context; /* do before l2tp_call_disconnect() */ _this->ppp = NULL; if (_this->state == L2TP_CALL_STATE_CLEANUP_WAIT) { /* no need to call l2tp_call_disconnect */ } else if (ppp->disconnect_code == PPP_DISCON_NO_INFORMATION) { l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ADMINISTRATIVE_REASON, 0, NULL, NULL, 0); } else { /* * RFC3145 L2TP Disconnect Cause Information */ struct l2tp_avp *avp[1]; struct _ppp_cause { struct l2tp_avp avp; uint16_t code; uint16_t proto; uint8_t direction; char message[128]; } __attribute__((__packed__)) ppp_cause; ppp_cause.avp.is_mandatory = 0; ppp_cause.avp.is_hidden = 0; ppp_cause.avp.vendor_id = 0; /* ietf */ ppp_cause.avp.attr_type = L2TP_AVP_TYPE_PPP_DISCONNECT_CAUSE_CODE; ppp_cause.code = htons(ppp->disconnect_code); ppp_cause.proto = htons(ppp->disconnect_proto); ppp_cause.direction = ppp->disconnect_direction; ppp_cause.avp.length = offsetof(struct _ppp_cause, message[0]); if (ppp->disconnect_message != NULL) { strlcpy(ppp_cause.message, ppp->disconnect_message, sizeof(ppp_cause.message)); ppp_cause.avp.length += strlen(ppp_cause.message); } avp[0] = &ppp_cause.avp; l2tp_call_disconnect(_this, L2TP_CDN_RCODE_ERROR_CODE, L2TP_ECODE_GENERIC_ERROR, "Disconnected by local PPP", avp, 1); } l2tp_call_log(_this, LOG_NOTICE, "logtype=PPPUnbind"); } /* notify disconnection to ppp to terminate or free of ppp */ static void l2tp_call_notify_down(l2tp_call *_this) { if (_this->ppp != NULL) ppp_phy_downed(_this->ppp); } /* bind ppp */ static int l2tp_call_bind_ppp(l2tp_call *_this, dialin_proxy_info *dpi) { int code, errcode; npppd_ppp *ppp; code = L2TP_CDN_RCODE_BUSY; errcode = 0; ppp = NULL; if ((ppp = ppp_create()) == NULL) goto fail; ASSERT(_this->ppp == NULL); if (_this->ppp != NULL) return -1; _this->ppp = ppp; ppp->tunnel_type = NPPPD_TUNNEL_L2TP; ppp->tunnel_session_id = _this->session_id; ppp->phy_context = _this; ppp->send_packet = l2tp_call_ppp_output; ppp->phy_close = l2tp_call_closed_by_ppp; strlcpy(ppp->phy_label, L2TP_CTRL_LISTENER_TUN_NAME(_this->ctrl), sizeof(ppp->phy_label)); L2TP_CALL_ASSERT(sizeof(ppp->phy_info) >= _this->ctrl->peer.ss_len); memcpy(&ppp->phy_info, &_this->ctrl->peer, MINIMUM(sizeof(ppp->phy_info), _this->ctrl->peer.ss_len)); strlcpy(ppp->calling_number, _this->calling_number, sizeof(ppp->calling_number)); if (ppp_init(npppd_get_npppd(), ppp) != 0) { l2tp_call_log(_this, LOG_ERR, "failed binding ppp"); goto fail; } l2tp_call_log(_this, LOG_NOTICE, "logtype=PPPBind ppp=%d", ppp->id); if (DIALIN_PROXY_IS_REQUESTED(dpi)) { if (!L2TP_CTRL_CONF(_this->ctrl)->accept_dialin) { l2tp_call_log(_this, LOG_ERR, "'accept_dialin' is 'false' in the setting."); code = L2TP_CDN_RCODE_ERROR_CODE; errcode = L2TP_ECODE_INVALID_MESSAGE; goto fail; } if (ppp_dialin_proxy_prepare(ppp, dpi) != 0) { code = L2TP_CDN_RCODE_TEMP_NOT_AVALIABLE; goto fail; } } ppp_start(ppp); return 0; fail: if (ppp != NULL) ppp_destroy(ppp); _this->ppp = NULL; l2tp_call_disconnect(_this, code, errcode, NULL, NULL, 0); return 1; }