diff options
Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_ipsec_pxy.c')
| -rw-r--r-- | sys/contrib/ipfilter/netinet/ip_ipsec_pxy.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_ipsec_pxy.c b/sys/contrib/ipfilter/netinet/ip_ipsec_pxy.c new file mode 100644 index 0000000..e88a6b9 --- /dev/null +++ b/sys/contrib/ipfilter/netinet/ip_ipsec_pxy.c @@ -0,0 +1,341 @@ +/* + * Copyright (C) 2001-2003 by Darren Reed + * + * See the IPFILTER.LICENCE file for details on licencing. + * + * Simple ISAKMP transparent proxy for in-kernel use. For use with the NAT + * code. + * + * $Id: ip_ipsec_pxy.c,v 2.20.2.8 2006/07/14 06:12:14 darrenr Exp $ + * + */ +#define IPF_IPSEC_PROXY + + +int ippr_ipsec_init __P((void)); +void ippr_ipsec_fini __P((void)); +int ippr_ipsec_new __P((fr_info_t *, ap_session_t *, nat_t *)); +void ippr_ipsec_del __P((ap_session_t *)); +int ippr_ipsec_inout __P((fr_info_t *, ap_session_t *, nat_t *)); +int ippr_ipsec_match __P((fr_info_t *, ap_session_t *, nat_t *)); + +static frentry_t ipsecfr; +static ipftq_t *ipsecnattqe; +static ipftq_t *ipsecstatetqe; +static char ipsec_buffer[1500]; + +int ipsec_proxy_init = 0; +int ipsec_proxy_ttl = 60; + +/* + * IPSec application proxy initialization. + */ +int ippr_ipsec_init() +{ + bzero((char *)&ipsecfr, sizeof(ipsecfr)); + ipsecfr.fr_ref = 1; + ipsecfr.fr_flags = FR_OUTQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; + MUTEX_INIT(&ipsecfr.fr_lock, "IPsec proxy rule lock"); + ipsec_proxy_init = 1; + + ipsecnattqe = fr_addtimeoutqueue(&nat_utqe, ipsec_proxy_ttl); + if (ipsecnattqe == NULL) + return -1; + ipsecstatetqe = fr_addtimeoutqueue(&ips_utqe, ipsec_proxy_ttl); + if (ipsecstatetqe == NULL) { + if (fr_deletetimeoutqueue(ipsecnattqe) == 0) + fr_freetimeoutqueue(ipsecnattqe); + ipsecnattqe = NULL; + return -1; + } + + ipsecnattqe->ifq_flags |= IFQF_PROXY; + ipsecstatetqe->ifq_flags |= IFQF_PROXY; + + ipsecfr.fr_age[0] = ipsec_proxy_ttl; + ipsecfr.fr_age[1] = ipsec_proxy_ttl; + return 0; +} + + +void ippr_ipsec_fini() +{ + if (ipsecnattqe != NULL) { + if (fr_deletetimeoutqueue(ipsecnattqe) == 0) + fr_freetimeoutqueue(ipsecnattqe); + } + ipsecnattqe = NULL; + if (ipsecstatetqe != NULL) { + if (fr_deletetimeoutqueue(ipsecstatetqe) == 0) + fr_freetimeoutqueue(ipsecstatetqe); + } + ipsecstatetqe = NULL; + + if (ipsec_proxy_init == 1) { + MUTEX_DESTROY(&ipsecfr.fr_lock); + ipsec_proxy_init = 0; + } +} + + +/* + * Setup for a new IPSEC proxy. + */ +int ippr_ipsec_new(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + ipsec_pxy_t *ipsec; + fr_info_t fi; + ipnat_t *ipn; + char *ptr; + int p, off, dlen, ttl; + mb_t *m; + ip_t *ip; + + off = fin->fin_plen - fin->fin_dlen + fin->fin_ipoff; + bzero(ipsec_buffer, sizeof(ipsec_buffer)); + ip = fin->fin_ip; + m = fin->fin_m; + + dlen = M_LEN(m) - off; + if (dlen < 16) + return -1; + COPYDATA(m, off, MIN(sizeof(ipsec_buffer), dlen), ipsec_buffer); + + if (nat_outlookup(fin, 0, IPPROTO_ESP, nat->nat_inip, + ip->ip_dst) != NULL) + return -1; + + aps->aps_psiz = sizeof(*ipsec); + KMALLOCS(aps->aps_data, ipsec_pxy_t *, sizeof(*ipsec)); + if (aps->aps_data == NULL) + return -1; + + ipsec = aps->aps_data; + bzero((char *)ipsec, sizeof(*ipsec)); + + /* + * Create NAT rule against which the tunnel/transport mapping is + * created. This is required because the current NAT rule does not + * describe ESP but UDP instead. + */ + ipn = &ipsec->ipsc_rule; + ttl = IPF_TTLVAL(ipsecnattqe->ifq_ttl); + ipn->in_tqehead[0] = fr_addtimeoutqueue(&nat_utqe, ttl); + ipn->in_tqehead[1] = fr_addtimeoutqueue(&nat_utqe, ttl); + ipn->in_ifps[0] = fin->fin_ifp; + ipn->in_apr = NULL; + ipn->in_use = 1; + ipn->in_hits = 1; + ipn->in_nip = ntohl(nat->nat_outip.s_addr); + ipn->in_ippip = 1; + ipn->in_inip = nat->nat_inip.s_addr; + ipn->in_inmsk = 0xffffffff; + ipn->in_outip = fin->fin_saddr; + ipn->in_outmsk = nat->nat_outip.s_addr; + ipn->in_srcip = fin->fin_saddr; + ipn->in_srcmsk = 0xffffffff; + ipn->in_redir = NAT_MAP; + bcopy(nat->nat_ptr->in_ifnames[0], ipn->in_ifnames[0], + sizeof(ipn->in_ifnames[0])); + ipn->in_p = IPPROTO_ESP; + + bcopy((char *)fin, (char *)&fi, sizeof(fi)); + fi.fin_state = NULL; + fi.fin_nat = NULL; + fi.fin_fi.fi_p = IPPROTO_ESP; + fi.fin_fr = &ipsecfr; + fi.fin_data[0] = 0; + fi.fin_data[1] = 0; + p = ip->ip_p; + ip->ip_p = IPPROTO_ESP; + fi.fin_flx &= ~(FI_TCPUDP|FI_STATE|FI_FRAG); + fi.fin_flx |= FI_IGNORE; + + ptr = ipsec_buffer; + bcopy(ptr, (char *)ipsec->ipsc_icookie, sizeof(ipsec_cookie_t)); + ptr += sizeof(ipsec_cookie_t); + bcopy(ptr, (char *)ipsec->ipsc_rcookie, sizeof(ipsec_cookie_t)); + /* + * The responder cookie should only be non-zero if the initiator + * cookie is non-zero. Therefore, it is safe to assume(!) that the + * cookies are both set after copying if the responder is non-zero. + */ + if ((ipsec->ipsc_rcookie[0]|ipsec->ipsc_rcookie[1]) != 0) + ipsec->ipsc_rckset = 1; + + ipsec->ipsc_nat = nat_new(&fi, ipn, &ipsec->ipsc_nat, + NAT_SLAVE|SI_WILDP, NAT_OUTBOUND); + if (ipsec->ipsc_nat != NULL) { + (void) nat_proto(&fi, ipsec->ipsc_nat, 0); + nat_update(&fi, ipsec->ipsc_nat, ipn); + + fi.fin_data[0] = 0; + fi.fin_data[1] = 0; + ipsec->ipsc_state = fr_addstate(&fi, &ipsec->ipsc_state, + SI_WILDP); + if (fi.fin_state != NULL) + fr_statederef((ipstate_t **)&fi.fin_state); + } + ip->ip_p = p & 0xff; + return 0; +} + + +/* + * For outgoing IKE packets. refresh timeouts for NAT & state entries, if + * we can. If they have disappeared, recreate them. + */ +int ippr_ipsec_inout(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + ipsec_pxy_t *ipsec; + fr_info_t fi; + ip_t *ip; + int p; + + if ((fin->fin_out == 1) && (nat->nat_dir == NAT_INBOUND)) + return 0; + + if ((fin->fin_out == 0) && (nat->nat_dir == NAT_OUTBOUND)) + return 0; + + ipsec = aps->aps_data; + + if (ipsec != NULL) { + ip = fin->fin_ip; + p = ip->ip_p; + + if ((ipsec->ipsc_nat == NULL) || (ipsec->ipsc_state == NULL)) { + bcopy((char *)fin, (char *)&fi, sizeof(fi)); + fi.fin_state = NULL; + fi.fin_nat = NULL; + fi.fin_fi.fi_p = IPPROTO_ESP; + fi.fin_fr = &ipsecfr; + fi.fin_data[0] = 0; + fi.fin_data[1] = 0; + ip->ip_p = IPPROTO_ESP; + fi.fin_flx &= ~(FI_TCPUDP|FI_STATE|FI_FRAG); + fi.fin_flx |= FI_IGNORE; + } + + /* + * Update NAT timeout/create NAT if missing. + */ + if (ipsec->ipsc_nat != NULL) + fr_queueback(&ipsec->ipsc_nat->nat_tqe); + else { + ipsec->ipsc_nat = nat_new(&fi, &ipsec->ipsc_rule, + &ipsec->ipsc_nat, + NAT_SLAVE|SI_WILDP, + nat->nat_dir); + if (ipsec->ipsc_nat != NULL) { + (void) nat_proto(&fi, ipsec->ipsc_nat, 0); + nat_update(&fi, ipsec->ipsc_nat, + &ipsec->ipsc_rule); + } + } + + /* + * Update state timeout/create state if missing. + */ + READ_ENTER(&ipf_state); + if (ipsec->ipsc_state != NULL) { + fr_queueback(&ipsec->ipsc_state->is_sti); + ipsec->ipsc_state->is_die = nat->nat_age; + RWLOCK_EXIT(&ipf_state); + } else { + RWLOCK_EXIT(&ipf_state); + fi.fin_data[0] = 0; + fi.fin_data[1] = 0; + ipsec->ipsc_state = fr_addstate(&fi, + &ipsec->ipsc_state, + SI_WILDP); + if (fi.fin_state != NULL) + fr_statederef((ipstate_t **)&fi.fin_state); + } + ip->ip_p = p; + } + return 0; +} + + +/* + * This extends the NAT matching to be based on the cookies associated with + * a session and found at the front of IKE packets. The cookies are always + * in the same order (not reversed depending on packet flow direction as with + * UDP/TCP port numbers). + */ +int ippr_ipsec_match(fin, aps, nat) +fr_info_t *fin; +ap_session_t *aps; +nat_t *nat; +{ + ipsec_pxy_t *ipsec; + u_32_t cookies[4]; + mb_t *m; + int off; + + nat = nat; /* LINT */ + + if ((fin->fin_dlen < sizeof(cookies)) || (fin->fin_flx & FI_FRAG)) + return -1; + + off = fin->fin_plen - fin->fin_dlen + fin->fin_ipoff; + ipsec = aps->aps_data; + m = fin->fin_m; + COPYDATA(m, off, sizeof(cookies), (char *)cookies); + + if ((cookies[0] != ipsec->ipsc_icookie[0]) || + (cookies[1] != ipsec->ipsc_icookie[1])) + return -1; + + if (ipsec->ipsc_rckset == 0) { + if ((cookies[2]|cookies[3]) == 0) { + return 0; + } + ipsec->ipsc_rckset = 1; + ipsec->ipsc_rcookie[0] = cookies[2]; + ipsec->ipsc_rcookie[1] = cookies[3]; + return 0; + } + + if ((cookies[2] != ipsec->ipsc_rcookie[0]) || + (cookies[3] != ipsec->ipsc_rcookie[1])) + return -1; + return 0; +} + + +/* + * clean up after ourselves. + */ +void ippr_ipsec_del(aps) +ap_session_t *aps; +{ + ipsec_pxy_t *ipsec; + + ipsec = aps->aps_data; + + if (ipsec != NULL) { + /* + * Don't bother changing any of the NAT structure details, + * *_del() is on a callback from aps_free(), from nat_delete() + */ + + READ_ENTER(&ipf_state); + if (ipsec->ipsc_state != NULL) { + ipsec->ipsc_state->is_die = fr_ticks + 1; + ipsec->ipsc_state->is_me = NULL; + fr_queuefront(&ipsec->ipsc_state->is_sti); + } + RWLOCK_EXIT(&ipf_state); + + ipsec->ipsc_state = NULL; + ipsec->ipsc_nat = NULL; + } +} |
