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#include "rpc.h" extern struct ops o; static int services_initialized = 0; static struct rpc_info ri; static int udp_rpc_socket = -1; static int tcp_rpc_socket = -1; static unsigned long rpc_xid_base = -1; /* The XID we send in queries is this random base number + the RPC prog number we are scanning for */ static int tcp_readlen=0; /* used in get_rpc_results but can be reset in send_rpc_query */ static void rpc_services_init() { char filename[512]; FILE *fp; unsigned char *tmpptr, *p; char line[1024]; int lineno = 0; services_initialized = 1; ri.num_alloc = 256; ri.num_used = 0; ri.names = cp_alloc(ri.num_alloc * sizeof(char *)); ri.numbers = cp_alloc(ri.num_alloc * sizeof(unsigned long)); if (nmap_fetchfile(filename, sizeof(filename), "nmap-rpc") == -1) { error("Unable to find nmap-rpc! Resorting to /etc/rpc"); strcpy(filename, "/etc/rpc"); } fp = fopen(filename, "r"); if (!fp) { fatal("Unable to open %s for reading rpc information", filename); } while(fgets(line, sizeof(line), fp)) { lineno++; p = line; if (ri.num_used == ri.num_alloc) { tmpptr = cp_alloc(ri.num_alloc * 3 * sizeof(char *)); memcpy(tmpptr, ri.names, ri.num_alloc * sizeof(char *)); ri.names = (char **) tmpptr; tmpptr = cp_alloc(ri.num_alloc * 3 * sizeof(unsigned long)); memcpy(tmpptr, ri.numbers, ri.num_alloc * sizeof(char *)); ri.numbers = (unsigned long *) tmpptr; ri.num_alloc *= 3; } while(*p && *p != '#' && !isalnum(*p)) p++; if (!*p || *p == '#') continue; tmpptr = strpbrk(p, " \t"); if (!tmpptr) continue; *tmpptr = '\0'; ri.names[ri.num_used] = cp_strdup(p); p = tmpptr + 1; while(*p && !isdigit(*p)) p++; if (!*p) continue; ri.numbers[ri.num_used] = strtoul(p, NULL, 10); ri.num_used++; } fclose(fp); return; } char *nmap_getrpcnamebynum(unsigned long num) { int i; if (!services_initialized) { rpc_services_init(); } for(i=0; i < ri.num_used; i++) { if (ri.numbers[i] == num) return ri.names[i]; } return NULL; } int get_rpc_procs(unsigned long **programs, int *num_programs) { if (!services_initialized) { rpc_services_init(); } *programs = ri.numbers; *num_programs = ri.num_used; if (ri.num_used == 0) fatal("Unable to find any valid rpc procedures in your rpc file! RPC scanning won't work for you"); return 0; } /* Send an RPC query to the specified host/port on the specified protocol looking for the specified RPC program. We cache our sending sockets to avoid recreating and (with TCP) reconnect() ing them each time */ int send_rpc_query(struct in_addr *target_host, unsigned short portno, int ipproto, unsigned long program, int scan_offset, int trynum,struct interface_info *ainfo) { static struct in_addr last_target_host; static int last_ipproto = -1; static unsigned short last_portno = 0; struct sockaddr_in sock; char rpch_buf[256]; struct rpc_hdr *rpch; int res; /* static int numruns = 0; if (numruns++ > 2) fatal("Done"); */ rpch = (struct rpc_hdr *) ((char *)rpch_buf + sizeof(unsigned long)); bzero(rpch, sizeof(struct rpc_hdr)); while(rpc_xid_base == -1) rpc_xid_base = (unsigned long) get_random_uint(); if (o.debugging > 1) { printf("Sending RPC probe for program %li to %hi/%s -- scan_offset=%d trynum=%d xid=%lX\n", program, portno, (ipproto == IPPROTO_TCP)? "tcp" : "udp", scan_offset, trynum, rpc_xid_base + ((portno & 0x3FFF) << 16) + (trynum << 30) + scan_offset); } /* First we check whether we have to create a new connection -- we need to if we have a new target_host, or a new portno, or the socket we want to use is -1 */ if (ipproto == IPPROTO_TCP && (last_target_host.s_addr != target_host->s_addr || last_portno != portno || last_ipproto != IPPROTO_TCP)) { /* New host or port -- kill our old tcp socket */ if (tcp_rpc_socket != -1) { close(tcp_rpc_socket); tcp_rpc_socket = -1; tcp_readlen = 0; } } last_ipproto = ipproto; last_target_host.s_addr = target_host->s_addr; last_portno = portno; bzero(&sock, sizeof(&sock)); sock.sin_family = AF_INET; sock.sin_addr.s_addr = target_host->s_addr; sock.sin_port = htons(portno); if (ipproto == IPPROTO_TCP && tcp_rpc_socket == -1) { if ((tcp_rpc_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) pfatal("Socket troubles in send_rpc_query"); /* I should unblock the socket here and timeout the connect() */ res = connect(tcp_rpc_socket, (struct sockaddr *) &sock, sizeof(struct sockaddr_in)); if (res == -1) { if (o.debugging) { gh_perror("Failed to connect to port %d of %s in send_rpc_query", portno, inet_ntoa(*target_host)); } close(tcp_rpc_socket); tcp_rpc_socket = -1; return -1; } unblock_socket(tcp_rpc_socket); } else if (ipproto == IPPROTO_UDP && udp_rpc_socket == -1) { if ((udp_rpc_socket = socket(AF_INET, SOCK_DGRAM, 0)) == -1) pfatal("UDP socket troubles in send_rpc_query"); unblock_socket(udp_rpc_socket); } /* OK, now that we have our sockets together, we form and send a query ... */ rpch->type_msg = htonl(RPC_MSG_CALL); /* rpc request */ rpch->version_rpc=htonl(2); /* portmapper v.2 (hmm, and v3&&4?) */ /*rpch->prog_proc=0;*/ /* proc_null() rpc function */ /*rpch->authcred_flavor=0;*/ /* AUTH_NULL for credentials */ /*rpch->authcred_length=0;*/ /* length of credentials is zero*/ /*rpch->authveri_flavor=0;*/ /* no verifiers field */ /*rpch->authveri_length=0;*/ /* zero length verifier field */ /* Bits are TTPPPPPPPPPPPPPP BBBBBBBBBBBBBBBB */ /* Where T are trynum bits, P is the lowest 14 bits of the port number, and B is the scan[] offset */ rpch->xid = htonl(rpc_xid_base + ((portno & 0x3FFF) << 16) + (trynum << 30) + scan_offset); rpch->prog_id = htonl(program); rpch->prog_ver = htonl(31337 + (rpc_xid_base & 0xFFFFF)); if (ipproto == IPPROTO_UDP) { /* Simply send this sucker we have created ... */ do { if (o.debugging > 1) hdump((char *) rpch, sizeof(struct rpc_hdr)); /* res = sendto(udp_rpc_socket, (char *)rpch, sizeof(struct rpc_hdr), 0,*/ res = Sendto("send_rpc_query",udp_rpc_socket, (char *)rpch, sizeof(struct rpc_hdr), 0, (struct sockaddr *) &sock, sizeof(struct sockaddr_in),ainfo); } while(res == -1 && (errno == EINTR || errno == ENOBUFS)); if (res == -1) { if (o.debugging) { gh_perror("Sendto in send_rpc_query"); close(udp_rpc_socket); udp_rpc_socket = -1; } return -1; } } else { /* TCP socket */ /* 0x80000000 means only 1 record marking */ *(unsigned long *)rpch_buf = htonl(sizeof(struct rpc_hdr) | 0x80000000); res = Write(tcp_rpc_socket, rpch_buf, sizeof(struct rpc_hdr) + sizeof(unsigned long)); if (res == -1) { if (o.debugging) { gh_perror("Write in send_rpc_query"); } close(tcp_rpc_socket); tcp_rpc_socket = -1; return -1; } } return 0; } int rpc_are_we_done(char *msg, int msg_len, struct hoststruct *target, struct portinfo *scan, struct scanstats *ss, struct portinfolist *pil, struct rpcscaninfo *rsi) { struct rpc_hdr_rcv *rpc_pack; unsigned long scan_offset; int trynum; struct portinfo *current; rpc_pack = (struct rpc_hdr_rcv *) msg; if (msg_len < 24 || msg_len > 32 || (msg_len < 32 && rpc_pack->accept_stat == PROG_MISMATCH)) { /* This is not a valid reply -- we kill the port (from an RPC perspective) */ if (o.debugging > 1) { printf("Port %hi/%s labelled NON_RPC because of invalid sized message (%d)\n", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TPC" : "UDP", msg_len); } rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } /* Now it is time to decode the scan offset */ scan_offset = ntohl(rpc_pack->xid); scan_offset -= rpc_xid_base; if (((scan_offset >> 16) & 0x3FFF) != (rsi->rpc_current_port->portno & 0x3FFF)) { /* Doh -- this doesn't seem right */ if (o.debugging > 1) { printf("Port %hi/%s labelled NON_RPC because ((scan_offset >> 16) & 0x3FFF) is %li\n", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TPC" : "UDP", ((scan_offset >> 16) & 0x3FFF)); } rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } trynum = scan_offset >> 30; scan_offset &= 0xFFFF; if (scan_offset >= rsi->rpc_number) { error("Invalid scan_offset returned in RPC packet"); rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } if (ntohl(rpc_pack->type_msg) != RPC_MSG_REPLY) { error("Strange -- RPC type is %d shoulb be RPC_MSG_REPLY (1)", ntohl(rpc_pack->type_msg)); return 0; } if (ntohl(rpc_pack->auth_flavor) != 0 /* AUTH_NULL */ || ntohl(rpc_pack->opaque_length != 0)) { error("Strange -- auth flavor/opaque_length are %d/%d should generally be 0/0", rpc_pack->auth_flavor, rpc_pack->opaque_length); rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } /* OK, now that we know what this is a response to, we delete the appropriate entry from our scanlist */ current = &scan[scan_offset]; if (current->state != PORT_TESTING && current->state != PORT_CLOSED && current->state != PORT_FIREWALLED) { error("Supposed scan_offset refers to port in state %s (should be testing,closed, or firewalld)", statenum2str(current->state)); rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } if (trynum > current->trynum) { error("Bogus trynum %d when we are only up to %d in get_rpc_results", trynum, current->trynum); rsi->rpc_status = RPC_STATUS_NOT_RPC; ss->numqueries_outstanding = 0; return 1; } if (current->next > -1) scan[current->next].prev = current->prev; if (current->prev > -1) scan[current->prev].next = current->next; if (current == pil->testinglist) pil->testinglist = (current->next >= 0)? &scan[current->next] : NULL; current->next = -1; current->prev = -1; /* Adjust timeouts ... */ adjust_timeouts(current->sent[trynum], &(target->to)); /* If a non-zero trynum finds a port that hasn't been discovered, the earlier packets(s) were probably dropped. So we decrease our numqueries_ideal, otherwise we increase it slightly */ if (trynum == 0) { ss->numqueries_ideal = MIN(ss->numqueries_ideal + (ss->packet_incr/ss->numqueries_ideal), ss->max_width); } else { if (!ss->alreadydecreasedqueries) { ss->alreadydecreasedqueries = 1; ss->numqueries_ideal *= ss->fallback_percent; if (ss->numqueries_ideal < 1.0) ss->numqueries_ideal = 1.0; if (o.debugging) { log_write(LOG_STDOUT, "Lost a packet, decreasing window to %d\n", (int) ss->numqueries_ideal); } } } if (current->state == PORT_TESTING) ss->numqueries_outstanding--; if (ntohl(rpc_pack->accept_stat) == PROG_UNAVAIL) { current->state = PORT_CLOSED; if (o.debugging > 1) { error("Port %hi/%s claims that it is not RPC service %li", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TCP" : "UDP", current->portno); } rsi->valid_responses_this_port++; return 0; } else if (ntohl(rpc_pack->accept_stat) == PROG_MISMATCH) { if (o.debugging > 1) { error("Port %hi/%s claims IT IS RPC service %li", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TCP" : "UDP", current->portno); } current->state = PORT_OPEN; rsi->rpc_status = RPC_STATUS_GOOD_PROG; rsi->rpc_program = current->portno; rsi->rpc_lowver = ntohl(rpc_pack->low_version); rsi->rpc_highver = ntohl(rpc_pack->high_version); rsi->valid_responses_this_port++; ss->numqueries_outstanding = 0; return 1; } else if (ntohl(rpc_pack->accept_stat) == SUCCESS) { error("Umm -- RPC returned success for bogus version -- thats OK I guess"); rsi->rpc_status = RPC_STATUS_GOOD_PROG; rsi->rpc_program = current->portno; rsi->rpc_lowver = rsi->rpc_highver = 0; rsi->valid_responses_this_port++; ss->numqueries_outstanding = 0; return 1; } else { fatal("Illegal rpc accept_stat"); } return 0; } void get_rpc_results(struct hoststruct *target, struct portinfo *scan, struct scanstats *ss, struct portinfolist *pil, struct rpcscaninfo *rsi) { int max_sd = -1; fd_set fds_r; int sres; struct timeval tv; int res; static char readbuf[512]; struct sockaddr_in from; int fromlen = sizeof(struct sockaddr_in); char *current_msg; unsigned long current_msg_len; if ((udp_rpc_socket == -1 && tcp_rpc_socket == -1) || ss->numqueries_outstanding <= 0) return; FD_ZERO(&fds_r); if (udp_rpc_socket >= 0 && rsi->rpc_current_port->proto == IPPROTO_UDP) { FD_SET(udp_rpc_socket, &fds_r); max_sd = udp_rpc_socket; } else if (tcp_rpc_socket >= 0 && rsi->rpc_current_port->proto == IPPROTO_TCP) { FD_SET(tcp_rpc_socket, &fds_r); if (tcp_rpc_socket > max_sd) max_sd = tcp_rpc_socket; } else { error("Unable to find listening socket in get_rpc_results"); return; } while (ss->numqueries_outstanding > 0) { /* Insure there is no timeout ... */ if (o.host_timeout) { gettimeofday(&tv, NULL); if (TIMEVAL_MSEC_SUBTRACT(tv, target->host_timeout) >= 0) { target->timedout = 1; return; } } tv.tv_sec = target->to.timeout / 1000000; tv.tv_usec = target->to.timeout % 1000000; sres = select(max_sd + 1, &fds_r, NULL, NULL, &tv); if (!sres) break; if (sres == -1 && errno == EINTR) continue; if (udp_rpc_socket >= 0 && FD_ISSET(udp_rpc_socket, &fds_r)) { res = recvfrom(udp_rpc_socket, readbuf, sizeof(readbuf), 0, (struct sockaddr *) &from, &fromlen); if (res < 0) { /* Doh! */ if (o.debugging || o.verbose) gh_perror("recvfrom in get_rpc_results"); ss->numqueries_outstanding = 0; rsi->rpc_status = RPC_STATUS_NOT_RPC; return; } if (o.debugging > 1) printf("Received %d byte UDP packet\n", res); /* Now we check that the response is from the expected host/port */ if (from.sin_addr.s_addr != target->host.s_addr || from.sin_port != htons(rsi->rpc_current_port->portno)) { if (o.debugging > 1) { printf("Received UDP packet from %d.%d.%d.%d/%hi when expecting packet from %d.%d.%d.%d/%hi\n", NIPQUAD(from.sin_addr.s_addr), ntohs(from.sin_port), NIPQUAD(target->host.s_addr), rsi->rpc_current_port->portno); } continue; } if (rpc_are_we_done(readbuf, res, target, scan, ss, pil, rsi) != 0) { return; } } else if (tcp_rpc_socket >= 0 && FD_ISSET(tcp_rpc_socket, &fds_r)) { do { res = read(tcp_rpc_socket, readbuf + tcp_readlen, sizeof(readbuf) - tcp_readlen); } while(res == -1 && errno == EINTR); if (res <= 0) { if (o.debugging) { if (res == -1) gh_perror("Failed to read() from tcp rpc socket in get_rpc_results"); else { error("Lamer on port %li closed RPC socket on me in get_rpc_results", rsi->rpc_current_port->portno); } } ss->numqueries_outstanding = 0; rsi->rpc_status = RPC_STATUS_NOT_RPC; return; } tcp_readlen += res; if (tcp_readlen < 28) { /* This is suspiciously small -- I'm assuming this is not the first part of a valid RPC packet */ if (o.debugging > 1) { printf("Port %hi/%s labelled NON_RPC because tcp_readlen is %d (should be at least 28)\n", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TCP" : "UDP", tcp_readlen); } ss->numqueries_outstanding = 0; rsi->rpc_status = RPC_STATUS_NOT_RPC; return; } /* I'm ignoring the multiple msg fragment possibility for now */ current_msg_len = ntohl((*(unsigned long *)readbuf)) & 0x7FFFFFFF; if (current_msg_len > tcp_readlen - 4) { if (o.debugging > 1) { printf("Port %hi/%s labelled NON_RPC because current_msg_len is %li while tcp_readlen is %d\n", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TCP" : "UDP", current_msg_len, tcp_readlen); } ss->numqueries_outstanding = 0; rsi->rpc_status = RPC_STATUS_NOT_RPC; return; } current_msg = readbuf + 4; do { if (rpc_are_we_done(current_msg, current_msg_len, target, scan, ss, pil, rsi) != 0) return; current_msg += current_msg_len; if ((current_msg - readbuf) + 4 < tcp_readlen) { current_msg_len = ntohl(*(unsigned long *) current_msg) & 0x7FFFFFFF; current_msg += 4; } else { if ((current_msg - readbuf) < tcp_readlen) { tcp_readlen -= current_msg - readbuf; memmove(readbuf, current_msg, tcp_readlen); } else tcp_readlen = 0; break; } if (current_msg_len < 24 || current_msg_len > 32) { ss->numqueries_outstanding = 0; if (o.debugging > 1) { printf("Port %hi/%s labelled NON_RPC because current_msg_len is %li\n", rsi->rpc_current_port->portno, (rsi->rpc_current_port->proto == IPPROTO_TCP)? "TCP" : "UDP", current_msg_len); } rsi->rpc_status = RPC_STATUS_NOT_RPC; return; } if ((current_msg - readbuf) + current_msg_len > tcp_readlen) { tcp_readlen -= current_msg - readbuf; memmove(readbuf +4 , current_msg, tcp_readlen); *(unsigned long *)&readbuf = htonl(current_msg_len); tcp_readlen += 4; break; } } while(1); } } return; } void close_rpc_query_sockets() { if (udp_rpc_socket != -1) { close(udp_rpc_socket); udp_rpc_socket = -1; } if (tcp_rpc_socket != -1) { close(tcp_rpc_socket); tcp_rpc_socket = -1; } }