/*************************************************************************** * services.cc -- Various functions relating to reading the nmap-services * * file and port <-> service mapping * * * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2022 Nmap Software LLC ("The Nmap * * Project"). Nmap is also a registered trademark of the Nmap Project. * * * * This program is distributed under the terms of the Nmap Public Source * * License (NPSL). The exact license text applying to a particular Nmap * * release or source code control revision is contained in the LICENSE * * file distributed with that version of Nmap or source code control * * revision. More Nmap copyright/legal information is available from * * https://nmap.org/book/man-legal.html, and further information on the * * NPSL license itself can be found at https://nmap.org/npsl/ . This * * header summarizes some key points from the Nmap license, but is no * * substitute for the actual license text. * * * * Nmap is generally free for end users to download and use themselves, * * including commercial use. It is available from https://nmap.org. * * * * The Nmap license generally prohibits companies from using and * * redistributing Nmap in commercial products, but we sell a special Nmap * * OEM Edition with a more permissive license and special features for * * this purpose. See https://nmap.org/oem/ * * * * If you have received a written Nmap license agreement or contract * * stating terms other than these (such as an Nmap OEM license), you may * * choose to use and redistribute Nmap under those terms instead. * * * * The official Nmap Windows builds include the Npcap software * * (https://npcap.com) for packet capture and transmission. It is under * * separate license terms which forbid redistribution without special * * permission. So the official Nmap Windows builds may not be * * redistributed without special permission (such as an Nmap OEM * * license). * * * * Source is provided to this software because we believe users have a * * right to know exactly what a program is going to do before they run it. * * This also allows you to audit the software for security holes. * * * * Source code also allows you to port Nmap to new platforms, fix bugs, * * and add new features. You are highly encouraged to submit your * * changes as a Github PR or by email to the dev@nmap.org mailing list * * for possible incorporation into the main distribution. Unless you * * specify otherwise, it is understood that you are offering us very * * broad rights to use your submissions as described in the Nmap Public * * Source License Contributor Agreement. This is important because we * * fund the project by selling licenses with various terms, and also * * because the inability to relicense code has caused devastating * * problems for other Free Software projects (such as KDE and NASM). * * * * The free version of Nmap is distributed in the hope that it will be * * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Warranties, * * indemnification and commercial support are all available through the * * Npcap OEM program--see https://nmap.org/oem/ * * * ***************************************************************************/ /* $Id$ */ #include "scan_lists.h" #include "services.h" #include "NmapOps.h" #include "charpool.h" #include "nmap_error.h" #include "utils.h" #include #include /* This structure is the key for looking up services in the port/proto -> service map. */ struct port_spec { int portno; std::string proto; /* Sort in the usual nmap-services order. */ bool operator<(const port_spec& other) const { if (this->portno < other.portno) return true; else if (this->portno > other.portno) return false; else return this->proto < other.proto; } }; /* This is a servent augmented by a frequency ratio. */ struct service_node : public servent { public: double ratio; }; /* Compare the ratios of two service nodes for top-ports purposes. Larger ratios come before smaller. */ bool service_node_ratio_compare(const service_node& a, const service_node& b) { return a.ratio > b.ratio; } extern NmapOps o; static int numtcpports; static int numudpports; static int numsctpports; static std::map service_table; static std::list services_by_ratio; static int services_initialized; static int ratio_format; // 0 = /etc/services no-ratio format. 1 = new nmap format static int nmap_services_init() { if (services_initialized) return 0; char filename[512]; FILE *fp; char servicename[128], proto[16] = { 0 }; u16 portno; const char *p; char line[1024]; int lineno = 0; int res; double ratio; int ratio_n, ratio_d; char ratio_str[32] = { 0 }; numtcpports = 0; numudpports = 0; numsctpports = 0; service_table.clear(); services_by_ratio.clear(); ratio_format = 0; if (nmap_fetchfile(filename, sizeof(filename), "nmap-services") != 1) { error("Unable to find nmap-services! Resorting to /etc/services"); #ifndef WIN32 strcpy(filename, "/etc/services"); #else int len = GetSystemDirectory(filename, 480); // be safe if(!len) fatal("GetSystemDirectory failed (%d) @#!#@", GetLastError()); else strcpy(filename + len, "\\drivers\\etc\\services"); #endif } fp = fopen(filename, "r"); if (!fp) { pfatal("Unable to open %s for reading service information", filename); } /* Record where this data file was found. */ o.loaded_data_files["nmap-services"] = filename; while(fgets(line, sizeof(line), fp)) { lineno++; p = line; while(*p && isspace((int) (unsigned char) *p)) p++; if (*p == '#') continue; res = sscanf(line, "%127s %hu/%15s %31s", servicename, &portno, proto, ratio_str); if (res == 3) { ratio = 0; } else if (res == 4) { if (strchr(ratio_str, '/')) { res = sscanf(ratio_str, "%d/%d", &ratio_n, &ratio_d); if (res != 2) fatal("%s:%d contains invalid port ratio string: %s", filename, lineno, ratio_str); if (ratio_n < 0 || ratio_d < 0) fatal("%s:%d contains an invalid negative value", filename, lineno); if (ratio_n > ratio_d) fatal("%s:%d has a ratio %g. All ratios must be < 1", filename, lineno, (double)ratio_n/ratio_d); if (ratio_d == 0) fatal("%s:%d has a ratio denominator of 0 causing a division by 0 error", filename, lineno); ratio = (double)ratio_n / ratio_d; ratio_format = 1; } else if (strncmp(ratio_str, "0.", 2) == 0) { /* We assume the ratio is in floating point notation already */ ratio = strtod(ratio_str, NULL); ratio_format = 1; } else { ratio = 0; } } else { continue; } port_spec ps; ps.portno = portno; ps.proto = proto; /* Now we make sure our service table doesn't have duplicates */ std::map::const_iterator i; i = service_table.find(ps); if (i != service_table.end()) { if (o.debugging) error("Port %d proto %s is duplicated in services file %s", portno, proto, filename); continue; } if (strncasecmp(proto, "tcp", 3) == 0) { numtcpports++; } else if (strncasecmp(proto, "udp", 3) == 0) { numudpports++; } else if (strncasecmp(proto, "sctp", 4) == 0) { numsctpports++; } else if (strncasecmp(proto, "ddp", 3) == 0) { /* ddp is some apple thing...we don't "do" that */ } else if (strncasecmp(proto, "divert", 6) == 0) { /* divert sockets are for freebsd's natd */ } else if (strncasecmp(proto, "#", 1) == 0) { /* possibly misplaced comment, but who cares? */ } else { if (o.debugging) error("Unknown protocol (%s) on line %d of services file %s.", proto, lineno, filename); continue; } struct service_node sn; sn.s_name = cp_strdup(servicename); sn.s_port = portno; sn.s_proto = cp_strdup(proto); sn.s_aliases = NULL; sn.ratio = ratio; service_table[ps] = sn; services_by_ratio.push_back(sn); } /* Sort the list of ports sorted by frequency for top-ports purposes. */ services_by_ratio.sort(service_node_ratio_compare); fclose(fp); services_initialized = 1; return 0; } void free_services() { /* This doesn't free anything, because the service_table is allocated statically. It just marks the table as needing to be reinitialized because other things have been freed, for example the cp_strdup-allocated members of service_node. */ services_initialized = 0; } /* Adds ports whose names match mask and one or more protocols * specified by range_type to porttbl. Increases the respective * protocol counts in ports. * Returns the number of ports added in total. */ int addportsfromservmask(const char *mask, u8 *porttbl, int range_type) { std::map::const_iterator i; int t = 0; if (!services_initialized && nmap_services_init() == -1) fatal("%s: Couldn't get port numbers", __func__); for (i = service_table.begin(); i != service_table.end(); i++) { const service_node& current = i->second; if (wildtest(mask, current.s_name)) { if ((range_type & SCAN_TCP_PORT) && strcmp(current.s_proto, "tcp") == 0) { porttbl[current.s_port] |= SCAN_TCP_PORT; t++; } if ((range_type & SCAN_UDP_PORT) && strcmp(current.s_proto, "udp") == 0) { porttbl[current.s_port] |= SCAN_UDP_PORT; t++; } if ((range_type & SCAN_SCTP_PORT) && strcmp(current.s_proto, "sctp") == 0) { porttbl[current.s_port] |= SCAN_SCTP_PORT; t++; } } } return t; } const struct servent *nmap_getservbyport(int port, const char *proto) { std::map::const_iterator i; port_spec ps; if (nmap_services_init() == -1) return NULL; ps.portno = port; ps.proto = proto; i = service_table.find(ps); if (i != service_table.end()) return &i->second; /* Couldn't find it ... oh well. */ return NULL; } static int port_compare(const void *a, const void *b) { unsigned short ua = *((unsigned short *) a), ub = *((unsigned short *) b); if (ua > ub) return 1; else return -1; } // is_port_member() returns true if serv is an element of ptsdata. // This could be implemented MUCH more efficiently but it should only be // called when you use a non-default top-ports or port-ratio value TOGETHER WITH // a -p portlist. static bool is_port_member(const struct scan_lists *ptsdata, const struct service_node *serv) { int i; if (strcmp(serv->s_proto, "tcp") == 0) { for (i=0; itcp_count; i++) if (serv->s_port == ptsdata->tcp_ports[i]) return true; } else if (strcmp(serv->s_proto, "udp") == 0) { for (i=0; iudp_count; i++) if (serv->s_port == ptsdata->udp_ports[i]) return true; } else if (strcmp(serv->s_proto, "sctp") == 0) { for (i=0; isctp_count; i++) if (serv->s_port == ptsdata->sctp_ports[i]) return true; } return false; } // gettoppts() sets its third parameter, a scan_list, with the most // common ports scanned by Nmap according to the ratios specified in // the nmap-services file. // // If level is below 1.0 then we treat it as a minimum ratio and we // add all ports with ratios above level. // // If level is 1 or above, we treat it as a "top ports" directive // and return the N highest ratio ports (where N==level). // // If the fourth parameter is not NULL, then the specified ports // are excluded first and only then are the top N ports taken // // This function doesn't support IP protocol scan so only call this // function if o.TCPScan() || o.UDPScan() || o.SCTPScan() void gettoppts(double level, const char *portlist, struct scan_lists * ports, const char *exclude_ports) { int ti=0, ui=0, si=0; struct scan_lists ptsdata = { 0 }; bool ptsdata_initialized = false; const struct service_node *current; std::list::const_iterator i; if (!services_initialized && nmap_services_init() == -1) fatal("%s: Couldn't get port numbers", __func__); if (ratio_format == 0) { if (level != -1) fatal("Unable to use --top-ports or --port-ratio with an old style (no-ratio) services file"); if (portlist){ getpts(portlist, ports); return; }else if (o.fastscan){ getpts("[-]", ports); return; }else{ getpts("1-1024,[1025-]", ports); return; } } // TOP PORT DEFAULTS if (level == -1) { if (portlist){ getpts(portlist, ports); return; } if (o.fastscan) level = 100; else level = 1000; } if (portlist){ getpts(portlist, &ptsdata); ptsdata_initialized = true; } else if (exclude_ports) { getpts("-", &ptsdata); ptsdata_initialized = true; } if (ptsdata_initialized && exclude_ports) removepts(exclude_ports, &ptsdata); if (level < 1) { for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) { current = &(*i); if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue; if (current->ratio >= level) { if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0) ports->tcp_count++; else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0) ports->udp_count++; else if (o.SCTPScan() && strcmp(current->s_proto, "sctp") == 0) ports->sctp_count++; } else { break; } } if (ports->tcp_count) ports->tcp_ports = (unsigned short *)safe_zalloc(ports->tcp_count * sizeof(unsigned short)); if (ports->udp_count) ports->udp_ports = (unsigned short *)safe_zalloc(ports->udp_count * sizeof(unsigned short)); if (ports->sctp_count) ports->sctp_ports = (unsigned short *)safe_zalloc(ports->sctp_count * sizeof(unsigned short)); ports->prots = NULL; for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) { current = &(*i); if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue; if (current->ratio >= level) { if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0) ports->tcp_ports[ti++] = current->s_port; else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0) ports->udp_ports[ui++] = current->s_port; else if (o.SCTPScan() && strcmp(current->s_proto, "sctp") == 0) ports->sctp_ports[si++] = current->s_port; } else { break; } } } else if (level >= 1) { if (level > 65536) fatal("Level argument to gettoppts (%g) is too large", level); if (o.TCPScan()) { ports->tcp_count = MIN((int) level, numtcpports); ports->tcp_ports = (unsigned short *)safe_zalloc(ports->tcp_count * sizeof(unsigned short)); } if (o.UDPScan()) { ports->udp_count = MIN((int) level, numudpports); ports->udp_ports = (unsigned short *)safe_zalloc(ports->udp_count * sizeof(unsigned short)); } if (o.SCTPScan()) { ports->sctp_count = MIN((int) level, numsctpports); ports->sctp_ports = (unsigned short *)safe_zalloc(ports->sctp_count * sizeof(unsigned short)); } ports->prots = NULL; for (i = services_by_ratio.begin(); i != services_by_ratio.end(); i++) { current = &(*i); if (ptsdata_initialized && !is_port_member(&ptsdata, current)) continue; if (o.TCPScan() && strcmp(current->s_proto, "tcp") == 0 && ti < ports->tcp_count) ports->tcp_ports[ti++] = current->s_port; else if (o.UDPScan() && strcmp(current->s_proto, "udp") == 0 && ui < ports->udp_count) ports->udp_ports[ui++] = current->s_port; else if (o.SCTPScan() && strcmp(current->s_proto, "sctp") == 0 && si < ports->sctp_count) ports->sctp_ports[si++] = current->s_port; } if (ti < ports->tcp_count) ports->tcp_count = ti; if (ui < ports->udp_count) ports->udp_count = ui; if (si < ports->sctp_count) ports->sctp_count = si; } else fatal("Argument to gettoppts (%g) should be a positive ratio below 1 or an integer of 1 or higher", level); if (ptsdata_initialized) { free_scan_lists(&ptsdata); ptsdata_initialized = false; } if (ports->tcp_count > 1) qsort(ports->tcp_ports, ports->tcp_count, sizeof(unsigned short), &port_compare); if (ports->udp_count > 1) qsort(ports->udp_ports, ports->udp_count, sizeof(unsigned short), &port_compare); if (ports->sctp_count > 1) qsort(ports->sctp_ports, ports->sctp_count, sizeof(unsigned short), &port_compare); if (o.debugging && level < 1) log_write(LOG_STDOUT, "PORTS: Using ports open on %g%% or more average hosts (TCP:%d, UDP:%d, SCTP:%d)\n", level*100, ports->tcp_count, ports->udp_count, ports->sctp_count); else if (o.debugging && level >= 1) log_write(LOG_STDOUT, "PORTS: Using top %d ports found open (TCP:%d, UDP:%d, SCTP:%d)\n", (int) level, ports->tcp_count, ports->udp_count, ports->sctp_count); }