/* $NetBSD: ip_proxy.c,v 1.8 2024/09/08 09:36:51 rillig Exp $ */ /* * Copyright (C) 2012 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. */ #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #include #include #include #include #include #if !defined(AIX) # include #endif #if !defined(_KERNEL) && !defined(__KERNEL__) # include # include # include # include # define _KERNEL # ifdef __OpenBSD__ struct file; # endif # include # undef _KERNEL #endif #if !defined(linux) # include #endif #include #if defined(_KERNEL) # if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \ !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi) && \ !defined(AIX) # include # endif # include # if !defined(__SVR4) && !defined(__svr4__) # include # endif #endif #if defined(_KERNEL) && (__FreeBSD_version >= 220000) # include # include #else # include #endif #if defined(__SVR4) || defined(__svr4__) # include # ifdef _KERNEL # include # endif # include # include #endif #if __FreeBSD__ > 2 # include #endif #include #ifdef sun # include #endif #include #include #include #ifndef linux # include #endif #include #include #include #include "netinet/ip_compat.h" #include "netinet/ip_fil.h" #include "netinet/ip_nat.h" #include "netinet/ip_state.h" #include "netinet/ip_proxy.h" #if (__FreeBSD_version >= 300000) # include #endif /* END OF INCLUDES */ #include "netinet/ip_dns_pxy.c" #include "netinet/ip_ftp_pxy.c" #include "netinet/ip_tftp_pxy.c" #include "netinet/ip_rcmd_pxy.c" #include "netinet/ip_pptp_pxy.c" #if defined(_KERNEL) # include "netinet/ip_irc_pxy.c" # include "netinet/ip_raudio_pxy.c" # include "netinet/ip_netbios_pxy.c" #endif #include "netinet/ip_ipsec_pxy.c" #include "netinet/ip_rpcb_pxy.c" #if !defined(lint) #if defined(__NetBSD__) #include __KERNEL_RCSID(0, "$NetBSD: ip_proxy.c,v 1.8 2024/09/08 09:36:51 rillig Exp $"); #else static const char rcsid[] = "@(#)Id: ip_proxy.c,v 1.1.1.2 2012/07/22 13:45:33 darrenr Exp"; #endif #endif #define AP_SESS_SIZE 53 static int ipf_proxy_fixseqack(fr_info_t *, ip_t *, ap_session_t *, int ); static aproxy_t *ipf_proxy_create_clone(ipf_main_softc_t *, aproxy_t *); typedef struct ipf_proxy_softc_s { int ips_proxy_debug; int ips_proxy_session_size; ap_session_t **ips_sess_tab; ap_session_t *ips_sess_list; aproxy_t *ips_proxies; int ips_init_run; ipftuneable_t *ipf_proxy_tune; } ipf_proxy_softc_t; static const ipftuneable_t ipf_proxy_tuneables[] = { { { (void *)offsetof(ipf_proxy_softc_t, ips_proxy_debug) }, "proxy_debug", 0, 0x1f, stsizeof(ipf_proxy_softc_t, ips_proxy_debug), 0, NULL, NULL }, { { NULL }, NULL, 0, 0, 0, 0, NULL, NULL} }; static aproxy_t *ap_proxylist = NULL; static aproxy_t ips_proxies[] = { #ifdef IPF_FTP_PROXY { NULL, NULL, "ftp", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_ftp_main_load, ipf_p_ftp_main_unload, ipf_p_ftp_soft_create, ipf_p_ftp_soft_destroy, NULL, NULL, ipf_p_ftp_new, ipf_p_ftp_del, ipf_p_ftp_in, ipf_p_ftp_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_TFTP_PROXY { NULL, NULL, "tftp", (char)IPPROTO_UDP, 0, 0, 0, ipf_p_tftp_main_load, ipf_p_tftp_main_unload, ipf_p_tftp_soft_create, ipf_p_tftp_soft_destroy, NULL, NULL, ipf_p_tftp_new, ipf_p_tftp_del, ipf_p_tftp_in, ipf_p_tftp_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_IRC_PROXY { NULL, NULL, "irc", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_irc_main_load, ipf_p_irc_main_unload, NULL, NULL, NULL, NULL, ipf_p_irc_new, NULL, NULL, ipf_p_irc_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_RCMD_PROXY { NULL, NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_rcmd_main_load, ipf_p_rcmd_main_unload, NULL, NULL, NULL, NULL, ipf_p_rcmd_new, ipf_p_rcmd_del, ipf_p_rcmd_in, ipf_p_rcmd_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_RAUDIO_PROXY { NULL, NULL, "raudio", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_raudio_main_load, ipf_p_raudio_main_unload, NULL, NULL, NULL, NULL, ipf_p_raudio_new, NULL, ipf_p_raudio_in, ipf_p_raudio_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_MSNRPC_PROXY { NULL, NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_msnrpc_init, ipf_p_msnrpc_fini, NULL, NULL, NULL, NULL, ipf_p_msnrpc_new, NULL, ipf_p_msnrpc_in, ipf_p_msnrpc_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_NETBIOS_PROXY { NULL, NULL, "netbios", (char)IPPROTO_UDP, 0, 0, 0, ipf_p_netbios_main_load, ipf_p_netbios_main_unload, NULL, NULL, NULL, NULL, NULL, NULL, NULL, ipf_p_netbios_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_IPSEC_PROXY { NULL, NULL, "ipsec", (char)IPPROTO_UDP, 0, 0, 0, NULL, NULL, ipf_p_ipsec_soft_create, ipf_p_ipsec_soft_destroy, ipf_p_ipsec_soft_init, ipf_p_ipsec_soft_fini, ipf_p_ipsec_new, ipf_p_ipsec_del, ipf_p_ipsec_inout, ipf_p_ipsec_inout, ipf_p_ipsec_match, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_DNS_PROXY { NULL, NULL, "dns", (char)IPPROTO_UDP, 0, 0, 0, NULL, NULL, ipf_p_dns_soft_create, ipf_p_dns_soft_destroy, NULL, NULL, ipf_p_dns_new, ipf_p_ipsec_del, ipf_p_dns_inout, ipf_p_dns_inout, ipf_p_dns_match, ipf_p_dns_ctl, NULL, NULL, NULL }, #endif #ifdef IPF_PPTP_PROXY { NULL, NULL, "pptp", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_pptp_main_load, ipf_p_pptp_main_unload, NULL, NULL, NULL, NULL, ipf_p_pptp_new, ipf_p_pptp_del, ipf_p_pptp_inout, ipf_p_pptp_inout, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_H323_PROXY { NULL, NULL, "h323", (char)IPPROTO_TCP, 0, 0, 0, ipf_p_h323_main_load, ipf_p_h323_main_unload, NULL, NULL, NULL, NULL, ipf_p_h323_new, ipf_p_h323_del, ipf_p_h323_in, NULL, NULL, NULL, NULL, NULL, NULL }, { NULL, NULL, "h245", (char)IPPROTO_TCP, 0, 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, ipf_p_h245_new, NULL, NULL, ipf_p_h245_out, NULL, NULL, NULL, NULL, NULL }, #endif #ifdef IPF_RPCB_PROXY # ifndef _KERNEL { NULL, NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, ipf_p_rpcb_new, ipf_p_rpcb_del, ipf_p_rpcb_in, ipf_p_rpcb_out, NULL, NULL, NULL, NULL, NULL }, # endif { NULL, NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0, 0, ipf_p_rpcb_main_load, ipf_p_rpcb_main_unload, NULL, NULL, NULL, NULL, ipf_p_rpcb_new, ipf_p_rpcb_del, ipf_p_rpcb_in, ipf_p_rpcb_out, NULL, NULL, NULL, NULL, NULL }, #endif { NULL, NULL, "", '\0', 0, 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } }; /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_main_load */ /* Returns: int - 0 == success, else failure. */ /* Parameters: Nil */ /* */ /* Initialise hook for kernel application proxies. */ /* Call the initialise routine for all the compiled in kernel proxies. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_main_load(void) { aproxy_t *ap; for (ap = ips_proxies; ap->apr_p; ap++) { if (ap->apr_load != NULL) (*ap->apr_load)(); } return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_main_unload */ /* Returns: int - 0 == success, else failure. */ /* Parameters: Nil */ /* */ /* Unload hook for kernel application proxies. */ /* Call the finialise routine for all the compiled in kernel proxies. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_main_unload(void) { aproxy_t *ap; for (ap = ips_proxies; ap->apr_p; ap++) if (ap->apr_unload != NULL) (*ap->apr_unload)(); for (ap = ap_proxylist; ap; ap = ap->apr_next) if (ap->apr_unload != NULL) (*ap->apr_unload)(); return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_soft_create */ /* Returns: void * - */ /* Parameters: softc(I) - pointer to soft context main structure */ /* */ /* Build the structure to hold all of the run time data to support proxies. */ /* ------------------------------------------------------------------------ */ void * ipf_proxy_soft_create(ipf_main_softc_t *softc) { ipf_proxy_softc_t *softp; aproxy_t *last; aproxy_t *apn; aproxy_t *ap; KMALLOC(softp, ipf_proxy_softc_t *); if (softp == NULL) return softp; bzero((char *)softp, sizeof(*softp)); #if defined(_KERNEL) softp->ips_proxy_debug = 0; #else softp->ips_proxy_debug = 2; #endif softp->ips_proxy_session_size = AP_SESS_SIZE; softp->ipf_proxy_tune = ipf_tune_array_copy(softp, sizeof(ipf_proxy_tuneables), ipf_proxy_tuneables); if (softp->ipf_proxy_tune == NULL) { ipf_proxy_soft_destroy(softc, softp); return NULL; } if (ipf_tune_array_link(softc, softp->ipf_proxy_tune) == -1) { ipf_proxy_soft_destroy(softc, softp); return NULL; } last = NULL; for (ap = ips_proxies; ap->apr_p; ap++) { apn = ipf_proxy_create_clone(softc, ap); if (apn == NULL) goto failed; if (last != NULL) last->apr_next = apn; else softp->ips_proxies = apn; last = apn; } for (ap = ips_proxies; ap != NULL; ap = ap->apr_next) { apn = ipf_proxy_create_clone(softc, ap); if (apn == NULL) goto failed; if (last != NULL) last->apr_next = apn; else softp->ips_proxies = apn; last = apn; } return softp; failed: ipf_proxy_soft_destroy(softc, softp); return NULL; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_soft_create */ /* Returns: void * - */ /* Parameters: softc(I) - pointer to soft context main structure */ /* orig(I) - pointer to proxy definition to copy */ /* */ /* This function clones a proxy definition given by orig and returns a */ /* a pointer to that copy. */ /* ------------------------------------------------------------------------ */ static aproxy_t * ipf_proxy_create_clone(ipf_main_softc_t *softc, aproxy_t *orig) { aproxy_t *apn; KMALLOC(apn, aproxy_t *); if (apn == NULL) return NULL; bcopy((char *)orig, (char *)apn, sizeof(*apn)); apn->apr_next = NULL; apn->apr_soft = NULL; if (apn->apr_create != NULL) { apn->apr_soft = (*apn->apr_create)(softc); if (apn->apr_soft == NULL) { KFREE(apn); return NULL; } } apn->apr_parent = orig; orig->apr_clones++; return apn; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_soft_create */ /* Returns: int - 0 == success, else failure. */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to proxy contect data */ /* */ /* Initialise the proxy context and walk through each of the proxies and */ /* call its initialisation function. This allows for proxies to do any */ /* local setup prior to actual use. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_soft_init(ipf_main_softc_t *softc, void *arg) { ipf_proxy_softc_t *softp; aproxy_t *ap; u_int size; int err; softp = arg; size = softp->ips_proxy_session_size * sizeof(ap_session_t *); KMALLOCS(softp->ips_sess_tab, ap_session_t **, size); if (softp->ips_sess_tab == NULL) return -1; bzero(softp->ips_sess_tab, size); for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) { if (ap->apr_init != NULL) { err = (*ap->apr_init)(softc, ap->apr_soft); if (err != 0) return -2; } } softp->ips_init_run = 1; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_soft_create */ /* Returns: int - 0 == success, else failure. */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to proxy contect data */ /* */ /* This function should always succeed. It is responsible for ensuring that */ /* the proxy context can be safely called when ipf_proxy_soft_destroy is */ /* called and suring all of the proxies have similarly been instructed. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_soft_fini(ipf_main_softc_t *softc, void *arg) { ipf_proxy_softc_t *softp = arg; aproxy_t *ap; for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) { if (ap->apr_fini != NULL) { (*ap->apr_fini)(softc, ap->apr_soft); } } if (softp->ips_sess_tab != NULL) { KFREES(softp->ips_sess_tab, softp->ips_proxy_session_size * sizeof(ap_session_t *)); softp->ips_sess_tab = NULL; } softp->ips_init_run = 0; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_soft_destroy */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to proxy contect data */ /* */ /* Free up all of the local data structures allocated during creation. */ /* ------------------------------------------------------------------------ */ void ipf_proxy_soft_destroy(ipf_main_softc_t *softc, void *arg) { ipf_proxy_softc_t *softp = arg; aproxy_t *ap; while ((ap = softp->ips_proxies) != NULL) { softp->ips_proxies = ap->apr_next; if (ap->apr_destroy != NULL) (*ap->apr_destroy)(softc, ap->apr_soft); ap->apr_parent->apr_clones--; KFREE(ap); } if (softp->ipf_proxy_tune != NULL) { ipf_tune_array_unlink(softc, softp->ipf_proxy_tune); KFREES(softp->ipf_proxy_tune, sizeof(ipf_proxy_tuneables)); softp->ipf_proxy_tune = NULL; } KFREE(softp); } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_flush */ /* Returns: Nil */ /* Parameters: arg(I) - pointer to proxy contect data */ /* how(I) - indicates the type of flush operation */ /* */ /* Walk through all of the proxies and pass on the flush command as either */ /* a flush or a clear. */ /* ------------------------------------------------------------------------ */ void ipf_proxy_flush(void *arg, int how) { ipf_proxy_softc_t *softp = arg; aproxy_t *ap; switch (how) { case 0 : for (ap = softp->ips_proxies; ap; ap = ap->apr_next) if (ap->apr_flush != NULL) (*ap->apr_flush)(ap, how); break; case 1 : for (ap = softp->ips_proxies; ap; ap = ap->apr_next) if (ap->apr_clear != NULL) (*ap->apr_clear)(ap); break; default : break; } } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_add */ /* Returns: int - 0 == success, else failure. */ /* Parameters: ap(I) - pointer to proxy structure */ /* */ /* Dynamically add a new kernel proxy. Ensure that it is unique in the */ /* collection compiled in and dynamically added. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_add(void *arg, aproxy_t *ap) { ipf_proxy_softc_t *softp = arg; aproxy_t *a; for (a = ips_proxies; a->apr_p; a++) if ((a->apr_p == ap->apr_p) && !strncmp(a->apr_label, ap->apr_label, sizeof(ap->apr_label))) { if (softp->ips_proxy_debug & 0x01) printf("ipf_proxy_add: %s/%d present (B)\n", a->apr_label, a->apr_p); return -1; } for (a = ap_proxylist; (a != NULL); a = a->apr_next) if ((a->apr_p == ap->apr_p) && !strncmp(a->apr_label, ap->apr_label, sizeof(ap->apr_label))) { if (softp->ips_proxy_debug & 0x01) printf("ipf_proxy_add: %s/%d present (D)\n", a->apr_label, a->apr_p); return -1; } ap->apr_next = ap_proxylist; ap_proxylist = ap; if (ap->apr_load != NULL) (*ap->apr_load)(); return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_ctl */ /* Returns: int - 0 == success, else error */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to proxy context */ /* ctl(I) - pointer to proxy control structure */ /* */ /* Check to see if the proxy this control request has come through for */ /* exists, and if it does and it has a control function then invoke that */ /* control function. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_ctl(ipf_main_softc_t *softc, void *arg, ap_ctl_t *ctl) { ipf_proxy_softc_t *softp = arg; aproxy_t *a; int error; a = ipf_proxy_lookup(arg, ctl->apc_p, ctl->apc_label); if (a == NULL) { if (softp->ips_proxy_debug & 0x01) printf("ipf_proxy_ctl: can't find %s/%d\n", ctl->apc_label, ctl->apc_p); IPFERROR(80001); error = ESRCH; } else if (a->apr_ctl == NULL) { if (softp->ips_proxy_debug & 0x01) printf("ipf_proxy_ctl: no ctl function for %s/%d\n", ctl->apc_label, ctl->apc_p); IPFERROR(80002); error = ENXIO; } else { error = (*a->apr_ctl)(softc, a->apr_soft, ctl); if ((error != 0) && (softp->ips_proxy_debug & 0x02)) printf("ipf_proxy_ctl: %s/%d ctl error %d\n", a->apr_label, a->apr_p, error); } return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_del */ /* Returns: int - 0 == success, else failure. */ /* Parameters: ap(I) - pointer to proxy structure */ /* */ /* Delete a proxy that has been added dynamically from those available. */ /* If it is in use, return 1 (do not destroy NOW), not in use 0 or -1 */ /* if it cannot be matched. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_del(aproxy_t *ap) { aproxy_t *a, **app; for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next) { if (a == ap) { a->apr_flags |= APR_DELETE; if (ap->apr_ref == 0 && ap->apr_clones == 0) { *app = a->apr_next; return 0; } return 1; } } return -1; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_ok */ /* Returns: int - 1 == good match else not. */ /* Parameters: fin(I) - pointer to packet information */ /* tcp(I) - pointer to TCP/UDP header */ /* nat(I) - pointer to current NAT session */ /* */ /* This function extends the NAT matching to ensure that a packet that has */ /* arrived matches the proxy information attached to the NAT rule. Notably, */ /* if the proxy is scheduled to be deleted then packets will not match the */ /* rule even if the rule is still active. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_ok(fr_info_t *fin, tcphdr_t *tcp, ipnat_t *np) { aproxy_t *apr = np->in_apr; u_short dport = np->in_odport; if ((apr == NULL) || (apr->apr_flags & APR_DELETE) || (fin->fin_p != apr->apr_p)) return 0; if ((tcp == NULL) && dport) return 0; return 1; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_ioctl */ /* Returns: int - 0 == success, else error */ /* Parameters: softc(I) - pointer to soft context main structure */ /* data(I) - pointer to ioctl data */ /* cmd(I) - ioctl command */ /* mode(I) - mode bits for device */ /* ctx(I) - pointer to context information */ /* */ /* ------------------------------------------------------------------------ */ int ipf_proxy_ioctl(ipf_main_softc_t *softc, void *data, ioctlcmd_t cmd, int mode, void *ctx) { ap_ctl_t ctl; void *ptr; int error; mode = mode; /* LINT */ switch (cmd) { case SIOCPROXY : error = ipf_inobj(softc, data, NULL, &ctl, IPFOBJ_PROXYCTL); if (error != 0) { return error; } ptr = NULL; if (ctl.apc_dsize > 0) { KMALLOCS(ptr, void *, ctl.apc_dsize); if (ptr == NULL) { IPFERROR(80003); error = ENOMEM; } else { error = copyinptr(softc, ctl.apc_data, ptr, ctl.apc_dsize); if (error == 0) ctl.apc_data = ptr; } } else { ctl.apc_data = NULL; error = 0; } if (error == 0) error = ipf_proxy_ctl(softc, softc->ipf_proxy_soft, &ctl); if ((error != 0) && (ptr != NULL)) { KFREES(ptr, ctl.apc_dsize); } break; default : IPFERROR(80004); error = EINVAL; } return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_match */ /* Returns: int - 0 == success, else error */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to current NAT session */ /* */ /* If a proxy has a match function, call that to do extended packet */ /* matching. Whilst other parts of the NAT code are rather lenient when it */ /* comes to the quality of the packet that it will transform, the proxy */ /* matching is not because they need to work with data, not just headers. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_match(fr_info_t *fin, nat_t *nat) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_proxy_softc_t *softp = softc->ipf_proxy_soft; aproxy_t *apr; ipnat_t *ipn; int result; ipn = nat->nat_ptr; if (softp->ips_proxy_debug & 0x04) printf("ipf_proxy_match(%lx,%lx) aps %lx ptr %lx\n", (u_long)fin, (u_long)nat, (u_long)nat->nat_aps, (u_long)ipn); if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_match: flx 0x%x (BAD|SHORT)\n", fin->fin_flx); return -1; } apr = ipn->in_apr; if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_match:apr %lx apr_flags 0x%x\n", (u_long)apr, apr ? apr->apr_flags : 0); return -1; } if (apr->apr_match != NULL) { result = (*apr->apr_match)(fin, nat->nat_aps, nat); if (result != 0) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_match: result %d\n", result); return -1; } } return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_new */ /* Returns: int - 0 == success, else error */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to current NAT session */ /* */ /* Allocate a new application proxy structure and fill it in with the */ /* relevant details. call the init function once complete, prior to */ /* returning. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_new(fr_info_t *fin, nat_t *nat) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_proxy_softc_t *softp = softc->ipf_proxy_soft; register ap_session_t *aps; aproxy_t *apr; if (softp->ips_proxy_debug & 0x04) printf("ipf_proxy_new(%lx,%lx) \n", (u_long)fin, (u_long)nat); if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_new: nat_ptr %lx nat_aps %lx\n", (u_long)nat->nat_ptr, (u_long)nat->nat_aps); return -1; } apr = nat->nat_ptr->in_apr; if ((apr->apr_flags & APR_DELETE) || (fin->fin_p != apr->apr_p)) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_new: apr_flags 0x%x p %d/%d\n", apr->apr_flags, fin->fin_p, apr->apr_p); return -1; } KMALLOC(aps, ap_session_t *); if (!aps) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_new: malloc failed (%lu)\n", (u_long)sizeof(ap_session_t)); return -1; } bzero((char *)aps, sizeof(*aps)); aps->aps_data = NULL; aps->aps_apr = apr; aps->aps_psiz = 0; if (apr->apr_new != NULL) if ((*apr->apr_new)(apr->apr_soft, fin, aps, nat) == -1) { if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) { KFREES(aps->aps_data, aps->aps_psiz); } KFREE(aps); if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_new: new(%lx) failed\n", (u_long)apr->apr_new); return -1; } aps->aps_nat = nat; aps->aps_next = softp->ips_sess_list; softp->ips_sess_list = aps; nat->nat_aps = aps; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_check */ /* Returns: int - -1 == error, 0 == success */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to current NAT session */ /* */ /* Check to see if a packet should be passed through an active proxy */ /* routine if one has been setup for it. We don't need to check the */ /* checksum here if IPFILTER_CKSUM is defined because if it is, a failed */ /* check causes FI_BAD to be set. */ /* ------------------------------------------------------------------------ */ int ipf_proxy_check(fr_info_t *fin, nat_t *nat) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_proxy_softc_t *softp = softc->ipf_proxy_soft; #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID) mb_t *m; #endif tcphdr_t *tcp = NULL; udphdr_t *udp = NULL; ap_session_t *aps; aproxy_t *apr; short adjlen; int dosum; ip_t *ip; short rv; int err; #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) u_32_t s1, s2, sd; #endif if (fin->fin_flx & FI_BAD) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_check: flx 0x%x (BAD)\n", fin->fin_flx); return -1; } #ifndef IPFILTER_CKSUM if ((fin->fin_out == 0) && (ipf_checkl4sum(fin) == -1)) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_check: l4 checksum failure %d\n", fin->fin_p); if (fin->fin_p == IPPROTO_TCP) softc->ipf_stats[fin->fin_out].fr_tcpbad++; return -1; } #endif aps = nat->nat_aps; if (aps != NULL) { /* * If there is data in this packet to be proxied then try and * get it all into the one buffer, else drop it. */ #if defined(MENTAT) || defined(HAVE_M_PULLDOWN) if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE)) if (ipf_coalesce(fin) == -1) { if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_check: %s %x\n", "coalesce failed", fin->fin_flx); return -1; } #endif ip = fin->fin_ip; if (fin->fin_cksum > FI_CK_SUMOK) dosum = 0; else dosum = 1; switch (fin->fin_p) { case IPPROTO_TCP : tcp = (tcphdr_t *)fin->fin_dp; #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID) m = fin->fin_qfm; if (dohwcksum && (m->b_ick_flag == ICK_VALID)) dosum = 0; #endif break; case IPPROTO_UDP : udp = (udphdr_t *)fin->fin_dp; break; default : break; } apr = aps->aps_apr; err = 0; if (fin->fin_out != 0) { if (apr->apr_outpkt != NULL) err = (*apr->apr_outpkt)(apr->apr_soft, fin, aps, nat); } else { if (apr->apr_inpkt != NULL) err = (*apr->apr_inpkt)(apr->apr_soft, fin, aps, nat); } rv = APR_EXIT(err); if (((softp->ips_proxy_debug & 0x08) && (rv != 0)) || (softp->ips_proxy_debug & 0x04)) printf("ipf_proxy_check: out %d err %x rv %d\n", fin->fin_out, err, rv); if (rv == 1) return -1; if (rv == 2) { ipf_proxy_deref(apr); nat->nat_aps = NULL; return -1; } /* * If err != 0 then the data size of the packet has changed * so we need to recalculate the header checksums for the * packet. */ adjlen = APR_INC(err); #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) s1 = LONG_SUM(fin->fin_plen - adjlen); s2 = LONG_SUM(fin->fin_plen); CALC_SUMD(s1, s2, sd); if ((err != 0) && (fin->fin_cksum < FI_CK_L4PART) && fin->fin_v == 4) ipf_fix_outcksum(0, &ip->ip_sum, sd, 0); #endif if (fin->fin_flx & FI_DOCKSUM) dosum = 1; #ifdef INET /* * For TCP packets, we may need to adjust the sequence and * acknowledgement numbers to reflect changes in size of the * data stream. * * For both TCP and UDP, recalculate the layer 4 checksum, * regardless, as we can't tell (here) if data has been * changed or not. */ if (tcp != NULL) { err = ipf_proxy_fixseqack(fin, ip, aps, adjlen); if (fin->fin_cksum == FI_CK_L4PART) { u_short sum = ntohs(tcp->th_sum); sum += adjlen; tcp->th_sum = htons(sum); } else if (fin->fin_cksum < FI_CK_L4PART) { tcp->th_sum = fr_cksum(fin, ip, IPPROTO_TCP, tcp); } } else if ((udp != NULL) && (udp->uh_sum != 0)) { if (fin->fin_cksum == FI_CK_L4PART) { u_short sum = ntohs(udp->uh_sum); sum += adjlen; udp->uh_sum = htons(sum); } else if (dosum) { udp->uh_sum = fr_cksum(fin, ip, IPPROTO_UDP, udp); } } #endif aps->aps_bytes += fin->fin_plen; aps->aps_pkts++; return 1; } return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_lookup */ /* Returns: int - -1 == error, 0 == success */ /* Parameters: arg(I) - pointer to proxy context information */ /* pr(I) - protocol number for proxy */ /* name(I) - proxy name */ /* */ /* Search for a proxy by the protocol it is being used with and its name. */ /* ------------------------------------------------------------------------ */ aproxy_t * ipf_proxy_lookup(void *arg, u_int pr, char *name) { ipf_proxy_softc_t *softp = arg; aproxy_t *ap; if (softp->ips_proxy_debug & 0x04) printf("ipf_proxy_lookup(%d,%s)\n", pr, name); for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) if ((ap->apr_p == pr) && !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) { ap->apr_ref++; return ap; } if (softp->ips_proxy_debug & 0x08) printf("ipf_proxy_lookup: failed for %d/%s\n", pr, name); return NULL; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_deref */ /* Returns: Nil */ /* Parameters: ap(I) - pointer to proxy structure */ /* */ /* Drop the reference counter associated with the proxy. */ /* ------------------------------------------------------------------------ */ void ipf_proxy_deref(aproxy_t *ap) { ap->apr_ref--; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_free */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* aps(I) - pointer to current proxy session */ /* Locks Held: ipf_nat_new, ipf_nat(W) */ /* */ /* Free up proxy session information allocated to be used with a NAT */ /* session. */ /* ------------------------------------------------------------------------ */ void ipf_proxy_free(ipf_main_softc_t *softc, ap_session_t *aps) { ipf_proxy_softc_t *softp = softc->ipf_proxy_soft; ap_session_t *a, **ap; aproxy_t *apr; if (!aps) return; for (ap = &softp->ips_sess_list; ((a = *ap) != NULL); ap = &a->aps_next) if (a == aps) { *ap = a->aps_next; break; } apr = aps->aps_apr; if ((apr != NULL) && (apr->apr_del != NULL)) (*apr->apr_del)(softc, aps); if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) KFREES(aps->aps_data, aps->aps_psiz); KFREE(aps); } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_fixseqack */ /* Returns: int - 2 if TCP ack/seq is changed, else 0 */ /* Parameters: fin(I) - pointer to packet information */ /* ip(I) - pointer to IP header */ /* nat(I) - pointer to current NAT session */ /* inc(I) - delta to apply to TCP sequence numbering */ /* */ /* Adjust the TCP sequence/acknowledge numbers in the TCP header based on */ /* whether or not the new header is past the point at which an adjustment */ /* occurred. This might happen because of (say) an FTP string being changed */ /* and the new string being a different length to the old. */ /* ------------------------------------------------------------------------ */ static int ipf_proxy_fixseqack(fr_info_t *fin, ip_t *ip, ap_session_t *aps, int inc) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_proxy_softc_t *softp = softc->ipf_proxy_soft; int sel, ch = 0, out, nlen; u_32_t seq1, seq2; tcphdr_t *tcp; short inc2; tcp = (tcphdr_t *)fin->fin_dp; out = fin->fin_out; /* * ip_len has already been adjusted by 'inc'. */ nlen = fin->fin_dlen; nlen -= (TCP_OFF(tcp) << 2); inc2 = inc; inc = (int)inc2; if (out != 0) { seq1 = (u_32_t)ntohl(tcp->th_seq); sel = aps->aps_sel[out]; /* switch to other set ? */ if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) && (seq1 > aps->aps_seqmin[!sel])) { if (softp->ips_proxy_debug & 0x10) printf("proxy out switch set seq %d -> %d %x > %x\n", sel, !sel, seq1, aps->aps_seqmin[!sel]); sel = aps->aps_sel[out] = !sel; } if (aps->aps_seqoff[sel]) { seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel]; if (seq1 > seq2) { seq2 = aps->aps_seqoff[sel]; seq1 += seq2; tcp->th_seq = htonl(seq1); ch = 1; } } if (inc && (seq1 > aps->aps_seqmin[!sel])) { aps->aps_seqmin[sel] = seq1 + nlen - 1; aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc; if (softp->ips_proxy_debug & 0x10) printf("proxy seq set %d at %x to %d + %d\n", sel, aps->aps_seqmin[sel], aps->aps_seqoff[sel], inc); } /***/ seq1 = ntohl(tcp->th_ack); sel = aps->aps_sel[1 - out]; /* switch to other set ? */ if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) && (seq1 > aps->aps_ackmin[!sel])) { if (softp->ips_proxy_debug & 0x10) printf("proxy out switch set ack %d -> %d %x > %x\n", sel, !sel, seq1, aps->aps_ackmin[!sel]); sel = aps->aps_sel[1 - out] = !sel; } if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) { seq2 = aps->aps_ackoff[sel]; tcp->th_ack = htonl(seq1 - seq2); ch = 1; } } else { seq1 = ntohl(tcp->th_seq); sel = aps->aps_sel[out]; /* switch to other set ? */ if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) && (seq1 > aps->aps_ackmin[!sel])) { if (softp->ips_proxy_debug & 0x10) printf("proxy in switch set ack %d -> %d %x > %x\n", sel, !sel, seq1, aps->aps_ackmin[!sel]); sel = aps->aps_sel[out] = !sel; } if (aps->aps_ackoff[sel]) { seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel]; if (seq1 > seq2) { seq2 = aps->aps_ackoff[sel]; seq1 += seq2; tcp->th_seq = htonl(seq1); ch = 1; } } if (inc && (seq1 > aps->aps_ackmin[!sel])) { aps->aps_ackmin[!sel] = seq1 + nlen - 1; aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc; if (softp->ips_proxy_debug & 0x10) printf("proxy ack set %d at %x to %d + %d\n", !sel, aps->aps_seqmin[!sel], aps->aps_seqoff[sel], inc); } /***/ seq1 = ntohl(tcp->th_ack); sel = aps->aps_sel[1 - out]; /* switch to other set ? */ if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) && (seq1 > aps->aps_seqmin[!sel])) { if (softp->ips_proxy_debug & 0x10) printf("proxy in switch set seq %d -> %d %x > %x\n", sel, !sel, seq1, aps->aps_seqmin[!sel]); sel = aps->aps_sel[1 - out] = !sel; } if (aps->aps_seqoff[sel] != 0) { if (softp->ips_proxy_debug & 0x10) printf("sel %d seqoff %d seq1 %x seqmin %x\n", sel, aps->aps_seqoff[sel], seq1, aps->aps_seqmin[sel]); if (seq1 > aps->aps_seqmin[sel]) { seq2 = aps->aps_seqoff[sel]; tcp->th_ack = htonl(seq1 - seq2); ch = 1; } } } if (softp->ips_proxy_debug & 0x10) printf("ipf_proxy_fixseqack: seq %u ack %u\n", (u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack)); return ch ? 2 : 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_rule_rev */ /* Returns: ipnat_t * - NULL = failure, else pointer to new rule */ /* Parameters: nat(I) - pointer to NAT session to create rule from */ /* */ /* This function creates a NAT rule that is based upon the reverse packet */ /* flow associated with this NAT session. Thus if this NAT session was */ /* created with a map rule then this function will create a rdr rule. */ /* Only address fields and network interfaces are assigned in this function */ /* and the address fields are formed such that an exact is required. If the */ /* original rule had a netmask, that is not replicated here not is it */ /* desired. The ultimate goal here is to create a NAT rule to support a NAT */ /* session being created that does not have a user configured rule. The */ /* classic example is supporting the FTP proxy, where a data channel needs */ /* to be setup, based on the addresses used for the control connection. In */ /* that case, this function is used to handle creating NAT rules to support */ /* data connections with the PORT and EPRT commands. */ /* ------------------------------------------------------------------------ */ ipnat_t * ipf_proxy_rule_rev(nat_t *nat) { ipnat_t *old; ipnat_t *ipn; int size; old = nat->nat_ptr; size = old->in_size; KMALLOCS(ipn, ipnat_t *, size); if (ipn == NULL) return NULL; bzero((char *)ipn, size); ipn->in_use = 1; ipn->in_hits = 1; ipn->in_ippip = 1; ipn->in_apr = NULL; ipn->in_size = size; ipn->in_pr[0] = old->in_pr[1]; ipn->in_pr[1] = old->in_pr[0]; ipn->in_v[0] = old->in_v[1]; ipn->in_v[1] = old->in_v[0]; ipn->in_ifps[0] = old->in_ifps[1]; ipn->in_ifps[1] = old->in_ifps[0]; ipn->in_flags = (old->in_flags | IPN_PROXYRULE); ipn->in_nsrcip6 = nat->nat_odst6; ipn->in_osrcip6 = nat->nat_ndst6; if ((old->in_redir & NAT_REDIRECT) != 0) { ipn->in_redir = NAT_MAP; if (ipn->in_v[0] == 4) { ipn->in_snip = ntohl(nat->nat_odstaddr); ipn->in_dnip = ntohl(nat->nat_nsrcaddr); } else { #ifdef USE_INET6 ipn->in_snip6 = nat->nat_odst6; ipn->in_dnip6 = nat->nat_nsrc6; #endif } ipn->in_ndstip6 = nat->nat_nsrc6; ipn->in_odstip6 = nat->nat_osrc6; } else { ipn->in_redir = NAT_REDIRECT; if (ipn->in_v[0] == 4) { ipn->in_snip = ntohl(nat->nat_odstaddr); ipn->in_dnip = ntohl(nat->nat_osrcaddr); } else { #ifdef USE_INET6 ipn->in_snip6 = nat->nat_odst6; ipn->in_dnip6 = nat->nat_osrc6; #endif } ipn->in_ndstip6 = nat->nat_osrc6; ipn->in_odstip6 = nat->nat_nsrc6; } IP6_SETONES(&ipn->in_osrcmsk6); IP6_SETONES(&ipn->in_nsrcmsk6); IP6_SETONES(&ipn->in_odstmsk6); IP6_SETONES(&ipn->in_ndstmsk6); ipn->in_namelen = old->in_namelen; ipn->in_ifnames[0] = old->in_ifnames[1]; ipn->in_ifnames[1] = old->in_ifnames[0]; bcopy(old->in_names, ipn->in_names, ipn->in_namelen); MUTEX_INIT(&ipn->in_lock, "ipnat rev rule lock"); return ipn; } /* ------------------------------------------------------------------------ */ /* Function: ipf_proxy_rule_fwd */ /* Returns: ipnat_t * - NULL = failure, else pointer to new rule */ /* Parameters: nat(I) - pointer to NAT session to create rule from */ /* */ /* The purpose and rationale of this function is much the same as the above */ /* function, ipf_proxy_rule_rev, except that a rule is created that matches */ /* the same direction as that of the existing NAT session. Thus if this NAT */ /* session was created with a map rule then this function will also create */ /* a data structure to represent a map rule. Whereas ipf_proxy_rule_rev is */ /* used to support PORT/EPRT, this function supports PASV/EPSV. */ /* ------------------------------------------------------------------------ */ ipnat_t * ipf_proxy_rule_fwd(nat_t *nat) { ipnat_t *old; ipnat_t *ipn; int size; old = nat->nat_ptr; size = old->in_size; KMALLOCS(ipn, ipnat_t *, size); if (ipn == NULL) return NULL; bzero((char *)ipn, size); ipn->in_use = 1; ipn->in_hits = 1; ipn->in_ippip = 1; ipn->in_apr = NULL; ipn->in_size = size; ipn->in_pr[0] = old->in_pr[0]; ipn->in_pr[1] = old->in_pr[1]; ipn->in_v[0] = old->in_v[0]; ipn->in_v[1] = old->in_v[1]; ipn->in_ifps[0] = nat->nat_ifps[0]; ipn->in_ifps[1] = nat->nat_ifps[1]; ipn->in_flags = (old->in_flags | IPN_PROXYRULE); ipn->in_nsrcip6 = nat->nat_nsrc6; ipn->in_osrcip6 = nat->nat_osrc6; ipn->in_ndstip6 = nat->nat_ndst6; ipn->in_odstip6 = nat->nat_odst6; ipn->in_redir = old->in_redir; if (ipn->in_v[0] == 4) { ipn->in_snip = ntohl(nat->nat_nsrcaddr); ipn->in_dnip = ntohl(nat->nat_ndstaddr); } else { #ifdef USE_INET6 ipn->in_snip6 = nat->nat_nsrc6; ipn->in_dnip6 = nat->nat_ndst6; #endif } IP6_SETONES(&ipn->in_osrcmsk6); IP6_SETONES(&ipn->in_nsrcmsk6); IP6_SETONES(&ipn->in_odstmsk6); IP6_SETONES(&ipn->in_ndstmsk6); ipn->in_namelen = old->in_namelen; ipn->in_ifnames[0] = old->in_ifnames[0]; ipn->in_ifnames[1] = old->in_ifnames[1]; bcopy(old->in_names, ipn->in_names, ipn->in_namelen); MUTEX_INIT(&ipn->in_lock, "ipnat fwd rule lock"); return ipn; }