/* $Id: upnpredirect.c,v 1.97 2020/06/06 17:55:24 nanard Exp $ */ /* vim: tabstop=4 shiftwidth=4 noexpandtab * MiniUPnP project * http://miniupnp.free.fr/ or https://miniupnp.tuxfamily.org/ * (c) 2006-2020 Thomas Bernard * This software is subject to the conditions detailed * in the LICENCE file provided within the distribution */ #include #include #include #include #include #include #include #include #include #include #include #include "macros.h" #include "config.h" #include "upnpredirect.h" #include "upnpglobalvars.h" #include "upnpevents.h" #include "portinuse.h" #include "upnputils.h" #if defined(USE_NETFILTER) #include "netfilter/iptcrdr.h" #endif #if defined(USE_PF) #include "pf/obsdrdr.h" #endif #if defined(USE_IPF) #include "ipf/ipfrdr.h" #endif #if defined(USE_IPFW) #include "ipfw/ipfwrdr.h" #endif #ifdef USE_MINIUPNPDCTL #include #include #endif #ifdef ENABLE_LEASEFILE #include #endif /* from */ #ifndef PRIu64 #define PRIu64 "llu" #endif /* proto_atoi() * convert the string "UDP" or "TCP" to IPPROTO_UDP and IPPROTO_UDP */ static int proto_atoi(const char * protocol) { int proto = IPPROTO_TCP; if(strcasecmp(protocol, "UDP") == 0) proto = IPPROTO_UDP; #ifdef IPPROTO_UDPLITE else if(strcasecmp(protocol, "UDPLITE") == 0) proto = IPPROTO_UDPLITE; #endif /* IPPROTO_UDPLITE */ return proto; } /* proto_itoa() * convert IPPROTO_UDP, IPPROTO_UDP, etc. to "UDP", "TCP" */ static const char * proto_itoa(int proto) { const char * protocol; switch(proto) { case IPPROTO_UDP: protocol = "UDP"; break; case IPPROTO_TCP: protocol = "TCP"; break; #ifdef IPPROTO_UDPLITE case IPPROTO_UDPLITE: protocol = "UDPLITE"; break; #endif /* IPPROTO_UDPLITE */ default: protocol = "*UNKNOWN*"; } return protocol; } #ifdef ENABLE_LEASEFILE static int lease_file_add(unsigned short eport, const char * iaddr, unsigned short iport, int proto, const char * desc, unsigned int timestamp) { FILE * fd; if (lease_file == NULL) return 0; fd = fopen( lease_file, "a"); if (fd==NULL) { syslog(LOG_ERR, "could not open lease file: %s", lease_file); return -1; } /* convert our time to unix time * if LEASEFILE_USE_REMAINING_TIME is defined, only the remaining time is stored */ if (timestamp != 0) { timestamp -= upnp_time(); #ifndef LEASEFILE_USE_REMAINING_TIME timestamp += time(NULL); #endif } fprintf(fd, "%s:%hu:%s:%hu:%u:%s\n", proto_itoa(proto), eport, iaddr, iport, timestamp, desc); fclose(fd); return 0; } static int lease_file_remove(unsigned short eport, int proto) { FILE* fd, *fdt; int tmp; char buf[512]; char str[32]; char tmpfilename[128]; int str_size, buf_size; if (lease_file == NULL) return 0; if (strlen( lease_file) + 7 > sizeof(tmpfilename)) { syslog(LOG_ERR, "Lease filename is too long"); return -1; } snprintf( tmpfilename, sizeof(tmpfilename), "%sXXXXXX", lease_file); fd = fopen( lease_file, "r"); if (fd==NULL) { return 0; } snprintf( str, sizeof(str), "%s:%u", proto_itoa(proto), eport); str_size = strlen(str); tmp = mkstemp(tmpfilename); if (tmp==-1) { fclose(fd); syslog(LOG_ERR, "could not open temporary lease file"); return -1; } fchmod(tmp, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); fdt = fdopen(tmp, "a"); buf[sizeof(buf)-1] = 0; while( fgets(buf, sizeof(buf)-1, fd) != NULL) { buf_size = strlen(buf); if (buf_size < str_size || strncmp(str, buf, str_size)!=0) { fwrite(buf, buf_size, 1, fdt); } } fclose(fdt); fclose(fd); if (rename(tmpfilename, lease_file) < 0) { syslog(LOG_ERR, "could not rename temporary lease file to %s", lease_file); remove(tmpfilename); } return 0; } /* reload_from_lease_file() * read lease_file and add the rules contained */ int reload_from_lease_file() { FILE * fd; char * p; unsigned short eport, iport; char * proto; char * iaddr; char * desc; char * rhost; unsigned int leaseduration; unsigned int timestamp; time_t current_time; #ifndef LEASEFILE_USE_REMAINING_TIME time_t current_unix_time; #endif char line[128]; int r; if(!lease_file) return -1; fd = fopen( lease_file, "r"); if (fd==NULL) { syslog(LOG_ERR, "could not open lease file: %s", lease_file); return -1; } if(unlink(lease_file) < 0) { syslog(LOG_WARNING, "could not unlink file %s : %m", lease_file); } current_time = upnp_time(); #ifndef LEASEFILE_USE_REMAINING_TIME current_unix_time = time(NULL); #endif while(fgets(line, sizeof(line), fd)) { syslog(LOG_DEBUG, "parsing lease file line '%s'", line); proto = line; p = strchr(line, ':'); if(!p) { syslog(LOG_ERR, "unrecognized data in lease file"); continue; } *(p++) = '\0'; iaddr = strchr(p, ':'); if(!iaddr) { syslog(LOG_ERR, "unrecognized data in lease file"); continue; } *(iaddr++) = '\0'; eport = (unsigned short)atoi(p); p = strchr(iaddr, ':'); if(!p) { syslog(LOG_ERR, "unrecognized data in lease file"); continue; } *(p++) = '\0'; iport = (unsigned short)atoi(p); p = strchr(p, ':'); if(!p) { syslog(LOG_ERR, "unrecognized data in lease file"); continue; } *(p++) = '\0'; desc = strchr(p, ':'); if(!desc) { syslog(LOG_ERR, "unrecognized data in lease file"); continue; } *(desc++) = '\0'; /*timestamp = (unsigned int)atoi(p);*/ timestamp = (unsigned int)strtoul(p, NULL, 10); /* trim description */ while(isspace(*desc)) desc++; p = desc; while(*(p+1)) p++; while(isspace(*p) && (p > desc)) *(p--) = '\0'; if(timestamp > 0) { #ifdef LEASEFILE_USE_REMAINING_TIME leaseduration = timestamp; timestamp += current_time; /* convert to our time */ #else if(timestamp <= (unsigned int)current_unix_time) { syslog(LOG_NOTICE, "already expired lease in lease file"); continue; } else { leaseduration = timestamp - current_unix_time; timestamp = leaseduration + current_time; /* convert to our time */ } #endif } else { leaseduration = 0; /* default value */ } rhost = NULL; r = upnp_redirect(rhost, eport, iaddr, iport, proto, desc, leaseduration); if(r == -1) { syslog(LOG_ERR, "Failed to redirect %hu -> %s:%hu protocol %s", eport, iaddr, iport, proto); } else if(r == -2) { /* Add the redirection again to the lease file */ lease_file_add(eport, iaddr, iport, proto_atoi(proto), desc, timestamp); } } fclose(fd); return 0; } #ifdef LEASEFILE_USE_REMAINING_TIME void lease_file_rewrite(void) { int index; unsigned short eport, iport; int proto; char iaddr[32]; char desc[64]; char rhost[40]; unsigned int timestamp; if (lease_file == NULL) return; remove(lease_file); for(index = 0; ; index++) { if(get_redirect_rule_by_index(index, 0/*ifname*/, &eport, iaddr, sizeof(iaddr), &iport, &proto, desc, sizeof(desc), rhost, sizeof(rhost), ×tamp, 0, 0) < 0) break; if(lease_file_add(eport, iaddr, iport, proto, desc, timestamp) < 0) break; } } #endif #endif /* upnp_redirect() * calls OS/fw dependent implementation of the redirection. * protocol should be the string "TCP" or "UDP" * returns: 0 on success * -1 failed to redirect * -2 already redirected * -3 permission check failed * -4 already redirected (other mechanism) */ int upnp_redirect(const char * rhost, unsigned short eport, const char * iaddr, unsigned short iport, const char * protocol, const char * desc, unsigned int leaseduration) { int proto, r; char iaddr_old[32]; char rhost_old[32]; unsigned short iport_old; struct in_addr address; unsigned int timestamp; proto = proto_atoi(protocol); if(inet_aton(iaddr, &address) <= 0) { syslog(LOG_ERR, "inet_aton(%s) FAILED", iaddr); return -1; } if(!check_upnp_rule_against_permissions(upnppermlist, num_upnpperm, eport, address, iport, desc)) { syslog(LOG_INFO, "redirection permission check failed for " "%hu->%s:%hu %s %s", eport, iaddr, iport, protocol, desc); return -3; } if (desc == NULL) desc = ""; /* assume empty description */ /* IGDv1 (WANIPConnection:1 Service Template Version 1.01 / Nov 12, 2001) * - 2.2.20.PortMappingDescription : * Overwriting Previous / Existing Port Mappings: * If the RemoteHost, ExternalPort, PortMappingProtocol and InternalClient * are exactly the same as an existing mapping, the existing mapping values * for InternalPort, PortMappingDescription, PortMappingEnabled and * PortMappingLeaseDuration are overwritten. * Rejecting a New Port Mapping: * In cases where the RemoteHost, ExternalPort and PortMappingProtocol * are the same as an existing mapping, but the InternalClient is * different, the action is rejected with an appropriate error. * Add or Reject New Port Mapping behavior based on vendor implementation: * In cases where the ExternalPort, PortMappingProtocol and InternalClient * are the same, but RemoteHost is different, the vendor can choose to * support both mappings simultaneously, or reject the second mapping * with an appropriate error. * * - 2.4.16.AddPortMapping * This action creates a new port mapping or overwrites an existing * mapping with the same internal client. If the ExternalPort and * PortMappingProtocol pair is already mapped to another internal client, * an error is returned. * * IGDv2 (WANIPConnection:2 Service Standardized DCP (SDCP) Sep 10, 2010) * Protocol ExternalPort RemoteHost InternalClient Result * = = ≠ ≠ Failure * = = ≠ = Failure or success * (vendor specific) * = = = ≠ Failure * = = = = Success (overwrite) */ rhost_old[0] = '\0'; r = get_redirect_rule(ext_if_name, eport, proto, iaddr_old, sizeof(iaddr_old), &iport_old, 0, 0, rhost_old, sizeof(rhost_old), ×tamp, 0, 0); if(r == 0) { if(strcmp(iaddr, iaddr_old)==0 && ((rhost == NULL && rhost_old[0]=='\0') || (rhost && (strcmp(rhost, "*") == 0) && rhost_old[0]=='\0') || (rhost && (strcmp(rhost, rhost_old) == 0)))) { syslog(LOG_INFO, "updating existing port mapping %hu %s (rhost '%s') => %s:%hu", eport, protocol, rhost_old, iaddr_old, iport_old); timestamp = (leaseduration > 0) ? upnp_time() + leaseduration : 0; if(iport != iport_old) { r = update_portmapping(ext_if_name, eport, proto, iport, desc, timestamp); } else { r = update_portmapping_desc_timestamp(ext_if_name, eport, proto, desc, timestamp); } #ifdef ENABLE_LEASEFILE if(r == 0) { lease_file_remove(eport, proto); lease_file_add(eport, iaddr, iport, proto, desc, timestamp); } #endif /* ENABLE_LEASEFILE */ return r; } else { syslog(LOG_INFO, "port %hu %s (rhost '%s') already redirected to %s:%hu", eport, protocol, rhost_old, iaddr_old, iport_old); return -2; } #ifdef CHECK_PORTINUSE } else if (port_in_use(ext_if_name, eport, proto, iaddr, iport) > 0) { syslog(LOG_INFO, "port %hu protocol %s already in use", eport, protocol); return -4; #endif /* CHECK_PORTINUSE */ } else { timestamp = (leaseduration > 0) ? upnp_time() + leaseduration : 0; syslog(LOG_INFO, "redirecting port %hu to %s:%hu protocol %s for: %s", eport, iaddr, iport, protocol, desc); return upnp_redirect_internal(rhost, eport, iaddr, iport, proto, desc, timestamp); } } int upnp_redirect_internal(const char * rhost, unsigned short eport, const char * iaddr, unsigned short iport, int proto, const char * desc, unsigned int timestamp) { /*syslog(LOG_INFO, "redirecting port %hu to %s:%hu protocol %s for: %s", eport, iaddr, iport, protocol, desc); */ if(disable_port_forwarding) return -1; if(add_redirect_rule2(ext_if_name, rhost, eport, iaddr, iport, proto, desc, timestamp) < 0) { return -1; } #ifdef ENABLE_LEASEFILE lease_file_add( eport, iaddr, iport, proto, desc, timestamp); #endif /* syslog(LOG_INFO, "creating pass rule to %s:%hu protocol %s for: %s", iaddr, iport, protocol, desc);*/ if(add_filter_rule2(ext_if_name, rhost, iaddr, eport, iport, proto, desc) < 0) { /* clean up the redirect rule */ #if !defined(__linux__) delete_redirect_rule(ext_if_name, eport, proto); #endif return -1; } if(timestamp > 0) { if(!nextruletoclean_timestamp || (timestamp < nextruletoclean_timestamp)) nextruletoclean_timestamp = timestamp; } #ifdef ENABLE_EVENTS /* the number of port mappings changed, we must * inform the subscribers */ upnp_event_var_change_notify(EWanIPC); #endif return 0; } /* Firewall independent code which call the FW dependent code. */ int upnp_get_redirection_infos(unsigned short eport, const char * protocol, unsigned short * iport, char * iaddr, int iaddrlen, char * desc, int desclen, char * rhost, int rhostlen, unsigned int * leaseduration) { int r; unsigned int timestamp; time_t current_time; if(desc && (desclen > 0)) desc[0] = '\0'; if(rhost && (rhostlen > 0)) rhost[0] = '\0'; r = get_redirect_rule(ext_if_name, eport, proto_atoi(protocol), iaddr, iaddrlen, iport, desc, desclen, rhost, rhostlen, ×tamp, 0, 0); if(r == 0 && timestamp > 0 && timestamp > (unsigned int)(current_time = upnp_time())) { *leaseduration = timestamp - current_time; } else { *leaseduration = 0; } return r; } int upnp_get_redirection_infos_by_index(int index, unsigned short * eport, char * protocol, unsigned short * iport, char * iaddr, int iaddrlen, char * desc, int desclen, char * rhost, int rhostlen, unsigned int * leaseduration) { /*char ifname[IFNAMSIZ];*/ int proto = 0; unsigned int timestamp; time_t current_time; if(desc && (desclen > 0)) desc[0] = '\0'; if(rhost && (rhostlen > 0)) rhost[0] = '\0'; if(get_redirect_rule_by_index(index, 0/*ifname*/, eport, iaddr, iaddrlen, iport, &proto, desc, desclen, rhost, rhostlen, ×tamp, 0, 0) < 0) return -1; else { current_time = upnp_time(); *leaseduration = (timestamp > (unsigned int)current_time) ? (timestamp - current_time) : 0; if(proto == IPPROTO_TCP) memcpy(protocol, "TCP", 4); #ifdef IPPROTO_UDPLITE else if(proto == IPPROTO_UDPLITE) memcpy(protocol, "UDPLITE", 8); #endif /* IPPROTO_UDPLITE */ else memcpy(protocol, "UDP", 4); return 0; } } /* called from natpmp.c too */ int _upnp_delete_redir(unsigned short eport, int proto) { int r; #if defined(__linux__) r = delete_redirect_and_filter_rules(eport, proto); #elif defined(USE_PF) r = delete_redirect_and_filter_rules(ext_if_name, eport, proto); #else r = delete_redirect_rule(ext_if_name, eport, proto); delete_filter_rule(ext_if_name, eport, proto); #endif #ifdef ENABLE_LEASEFILE lease_file_remove( eport, proto); #endif #ifdef ENABLE_EVENTS upnp_event_var_change_notify(EWanIPC); #endif return r; } int upnp_delete_redirection(unsigned short eport, const char * protocol) { syslog(LOG_INFO, "removing redirect rule port %hu %s", eport, protocol); return _upnp_delete_redir(eport, proto_atoi(protocol)); } /* upnp_get_portmapping_number_of_entries() */ int upnp_get_portmapping_number_of_entries() { #if defined(USE_PF) || defined(USE_NFTABLES) return get_redirect_rule_count(ext_if_name); #else int n = 0, r = 0; unsigned short eport, iport; char protocol[8], iaddr[32], desc[64], rhost[32]; unsigned int leaseduration; do { protocol[0] = '\0'; iaddr[0] = '\0'; desc[0] = '\0'; r = upnp_get_redirection_infos_by_index(n, &eport, protocol, &iport, iaddr, sizeof(iaddr), desc, sizeof(desc), rhost, sizeof(rhost), &leaseduration); n++; } while(r==0); return (n-1); #endif } /* functions used to remove unused rules * As a side effect, delete expired rules (based on LeaseDuration) */ struct rule_state * get_upnp_rules_state_list(int max_rules_number_target) { /*char ifname[IFNAMSIZ];*/ int proto; unsigned short iport; unsigned int timestamp; struct rule_state * tmp; struct rule_state * list = 0; struct rule_state * * p; int i = 0; time_t current_time; /*ifname[0] = '\0';*/ tmp = malloc(sizeof(struct rule_state)); if(!tmp) return 0; current_time = upnp_time(); nextruletoclean_timestamp = 0; while(get_redirect_rule_by_index(i, /*ifname*/0, &tmp->eport, 0, 0, &iport, &proto, 0, 0, 0,0, ×tamp, &tmp->packets, &tmp->bytes) >= 0) { tmp->to_remove = 0; if(timestamp > 0) { /* need to remove this port mapping ? */ if(timestamp <= (unsigned int)current_time) tmp->to_remove = 1; else if((nextruletoclean_timestamp <= (unsigned int)current_time) || (timestamp < nextruletoclean_timestamp)) nextruletoclean_timestamp = timestamp; } tmp->proto = (short)proto; /* add tmp to list */ tmp->next = list; list = tmp; /* prepare next iteration */ i++; tmp = malloc(sizeof(struct rule_state)); if(!tmp) break; } #ifdef PCP_PEER i=0; while(get_peer_rule_by_index(i, /*ifname*/0, &tmp->eport, 0, 0, &iport, &proto, 0, 0, 0,0,0, ×tamp, &tmp->packets, &tmp->bytes) >= 0) { tmp->to_remove = 0; if(timestamp > 0) { /* need to remove this port mapping ? */ if(timestamp <= (unsigned int)current_time) tmp->to_remove = 1; else if((nextruletoclean_timestamp <= (unsigned int)current_time) || (timestamp < nextruletoclean_timestamp)) nextruletoclean_timestamp = timestamp; } tmp->proto = (short)proto; /* add tmp to list */ tmp->next = list; list = tmp; /* prepare next iteration */ i++; tmp = malloc(sizeof(struct rule_state)); if(!tmp) break; } #endif free(tmp); /* remove the redirections that need to be removed */ for(p = &list, tmp = list; tmp; tmp = *p) { if(tmp->to_remove) { syslog(LOG_NOTICE, "remove port mapping %hu %s because it has expired", tmp->eport, proto_itoa(tmp->proto)); _upnp_delete_redir(tmp->eport, tmp->proto); *p = tmp->next; free(tmp); i--; } else { p = &(tmp->next); } } /* return empty list if not enough redirections */ if(i<=max_rules_number_target) while(list) { tmp = list; list = tmp->next; free(tmp); } /* return list */ return list; } void remove_unused_rules(struct rule_state * list) { char ifname[IFNAMSIZ]; unsigned short iport; struct rule_state * tmp; u_int64_t packets; u_int64_t bytes; unsigned int timestamp; int n = 0; while(list) { /* remove the rule if no traffic has used it */ if(get_redirect_rule(ifname, list->eport, list->proto, 0, 0, &iport, 0, 0, 0, 0, ×tamp, &packets, &bytes) >= 0) { if(packets == list->packets && bytes == list->bytes) { syslog(LOG_DEBUG, "removing unused mapping %hu %s : still " "%" PRIu64 "packets %" PRIu64 "bytes", list->eport, proto_itoa(list->proto), packets, bytes); _upnp_delete_redir(list->eport, list->proto); n++; } } tmp = list; list = tmp->next; free(tmp); } if(n>0) syslog(LOG_NOTICE, "removed %d unused rules", n); } /* upnp_get_portmappings_in_range() * return a list of all "external" ports for which a port * mapping exists */ unsigned short * upnp_get_portmappings_in_range(unsigned short startport, unsigned short endport, const char * protocol, unsigned int * number) { int proto; proto = proto_atoi(protocol); if(!number) return NULL; return get_portmappings_in_range(startport, endport, proto, number); } /* stuff for miniupnpdctl */ #ifdef USE_MINIUPNPDCTL void write_ruleset_details(int s) { int proto = 0; unsigned short eport, iport; char desc[64]; char iaddr[32]; char rhost[32]; unsigned int timestamp; u_int64_t packets; u_int64_t bytes; int i = 0; char buffer[256]; int n; write(s, "Ruleset :\n", 10); while(get_redirect_rule_by_index(i, 0/*ifname*/, &eport, iaddr, sizeof(iaddr), &iport, &proto, desc, sizeof(desc), rhost, sizeof(rhost), ×tamp, &packets, &bytes) >= 0) { n = snprintf(buffer, sizeof(buffer), "%2d %s %s:%hu->%s:%hu " "'%s' %u %" PRIu64 " %" PRIu64 "\n", /*"'%s' %llu %llu\n",*/ i, proto_itoa(proto), rhost, eport, iaddr, iport, desc, timestamp, packets, bytes); write(s, buffer, n); i++; } } #endif