Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Pscan is a mini port scanner implementation for busybox |
| 3 | * |
| 4 | * Copyright 2007 Tito Ragusa <farmatito@tiscali.it> |
| 5 | * |
Denys Vlasenko | 0ef64bd | 2010-08-16 20:14:46 +0200 | [diff] [blame] | 6 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 7 | */ |
Denys Vlasenko | 47367e1 | 2016-11-23 09:05:14 +0100 | [diff] [blame] | 8 | //config:config PSCAN |
| 9 | //config: bool "pscan" |
| 10 | //config: default y |
| 11 | //config: help |
| 12 | //config: Simple network port scanner. |
| 13 | |
| 14 | //applet:IF_PSCAN(APPLET(pscan, BB_DIR_USR_BIN, BB_SUID_DROP)) |
| 15 | |
| 16 | //kbuild:lib-$(CONFIG_PSCAN) += pscan.o |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 17 | |
Pere Orga | 5bc8c00 | 2011-04-11 03:29:49 +0200 | [diff] [blame] | 18 | //usage:#define pscan_trivial_usage |
| 19 | //usage: "[-cb] [-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT] HOST" |
| 20 | //usage:#define pscan_full_usage "\n\n" |
| 21 | //usage: "Scan a host, print all open ports\n" |
Pere Orga | 5bc8c00 | 2011-04-11 03:29:49 +0200 | [diff] [blame] | 22 | //usage: "\n -c Show closed ports too" |
| 23 | //usage: "\n -b Show blocked ports too" |
| 24 | //usage: "\n -p Scan from this port (default 1)" |
| 25 | //usage: "\n -P Scan up to this port (default 1024)" |
| 26 | //usage: "\n -t Timeout (default 5000 ms)" |
| 27 | //usage: "\n -T Minimum rtt (default 5 ms, increase for congested hosts)" |
| 28 | |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 29 | #include "libbb.h" |
| 30 | |
| 31 | /* debugging */ |
| 32 | #ifdef DEBUG_PSCAN |
| 33 | #define DMSG(...) bb_error_msg(__VA_ARGS__) |
| 34 | #define DERR(...) bb_perror_msg(__VA_ARGS__) |
| 35 | #else |
| 36 | #define DMSG(...) ((void)0) |
| 37 | #define DERR(...) ((void)0) |
| 38 | #endif |
| 39 | |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 40 | static const char *port_name(unsigned port) |
| 41 | { |
| 42 | struct servent *server; |
| 43 | |
| 44 | server = getservbyport(htons(port), NULL); |
| 45 | if (server) |
| 46 | return server->s_name; |
| 47 | return "unknown"; |
| 48 | } |
| 49 | |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 50 | /* We don't expect to see 1000+ seconds delay, unsigned is enough */ |
| 51 | #define MONOTONIC_US() ((unsigned)monotonic_us()) |
| 52 | |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 53 | int pscan_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Denis Vlasenko | a60f84e | 2008-07-05 09:18:54 +0000 | [diff] [blame] | 54 | int pscan_main(int argc UNUSED_PARAM, char **argv) |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 55 | { |
| 56 | const char *opt_max_port = "1024"; /* -P: default max port */ |
| 57 | const char *opt_min_port = "1"; /* -p: default min port */ |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 58 | const char *opt_timeout = "5000"; /* -t: default timeout in msec */ |
Denis Vlasenko | 49a128a | 2007-07-17 21:42:59 +0000 | [diff] [blame] | 59 | /* We estimate rtt and wait rtt*4 before concluding that port is |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 60 | * totally blocked. min rtt of 5 ms may be too low if you are |
| 61 | * scanning an Internet host behind saturated/traffic shaped link. |
| 62 | * Rule of thumb: with min_rtt of N msec, scanning 1000 ports |
| 63 | * will take N seconds at absolute minimum */ |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 64 | const char *opt_min_rtt = "5"; /* -T: default min rtt in msec */ |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 65 | const char *result_str; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 66 | len_and_sockaddr *lsap; |
| 67 | int s; |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 68 | unsigned opt; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 69 | unsigned port, max_port, nports; |
| 70 | unsigned closed_ports = 0; |
| 71 | unsigned open_ports = 0; |
| 72 | /* all in usec */ |
| 73 | unsigned timeout; |
| 74 | unsigned min_rtt; |
| 75 | unsigned rtt_4; |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 76 | unsigned start, diff; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 77 | |
| 78 | opt_complementary = "=1"; /* exactly one non-option */ |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 79 | opt = getopt32(argv, "cbp:P:t:T:", &opt_min_port, &opt_max_port, &opt_timeout, &opt_min_rtt); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 80 | argv += optind; |
| 81 | max_port = xatou_range(opt_max_port, 1, 65535); |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 82 | port = xatou_range(opt_min_port, 1, max_port); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 83 | nports = max_port - port + 1; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 84 | min_rtt = xatou_range(opt_min_rtt, 1, INT_MAX/1000 / 4) * 1000; |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 85 | timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000; |
| 86 | /* Initial rtt is BIG: */ |
| 87 | rtt_4 = timeout; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 88 | |
| 89 | DMSG("min_rtt %u timeout %u", min_rtt, timeout); |
| 90 | |
| 91 | lsap = xhost2sockaddr(*argv, port); |
| 92 | printf("Scanning %s ports %u to %u\n Port\tProto\tState\tService\n", |
| 93 | *argv, port, max_port); |
| 94 | |
| 95 | for (; port <= max_port; port++) { |
| 96 | DMSG("rtt %u", rtt_4); |
| 97 | |
| 98 | /* The SOCK_STREAM socket type is implemented on the TCP/IP protocol. */ |
Denys Vlasenko | ca18311 | 2011-04-07 17:52:20 +0200 | [diff] [blame] | 99 | set_nport(&lsap->u.sa, htons(port)); |
Bernhard Reutner-Fischer | 8c69afd | 2008-01-29 10:33:34 +0000 | [diff] [blame] | 100 | s = xsocket(lsap->u.sa.sa_family, SOCK_STREAM, 0); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 101 | /* We need unblocking socket so we don't need to wait for ETIMEOUT. */ |
| 102 | /* Nonblocking connect typically "fails" with errno == EINPROGRESS */ |
| 103 | ndelay_on(s); |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 104 | |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 105 | DMSG("connect to port %u", port); |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 106 | result_str = NULL; |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 107 | start = MONOTONIC_US(); |
Bernhard Reutner-Fischer | 8c69afd | 2008-01-29 10:33:34 +0000 | [diff] [blame] | 108 | if (connect(s, &lsap->u.sa, lsap->len) == 0) { |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 109 | /* Unlikely, for me even localhost fails :) */ |
| 110 | DMSG("connect succeeded"); |
| 111 | goto open; |
| 112 | } |
| 113 | /* Check for untypical errors... */ |
| 114 | if (errno != EAGAIN && errno != EINPROGRESS |
| 115 | && errno != ECONNREFUSED |
| 116 | ) { |
| 117 | bb_perror_nomsg_and_die(); |
| 118 | } |
| 119 | |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 120 | diff = 0; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 121 | while (1) { |
| 122 | if (errno == ECONNREFUSED) { |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 123 | if (opt & 1) /* -c: show closed too */ |
| 124 | result_str = "closed"; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 125 | closed_ports++; |
| 126 | break; |
| 127 | } |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 128 | DERR("port %u errno %d @%u", port, errno, diff); |
| 129 | |
| 130 | if (diff > rtt_4) { |
| 131 | if (opt & 2) /* -b: show blocked too */ |
| 132 | result_str = "blocked"; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 133 | break; |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 134 | } |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 135 | /* Can sleep (much) longer than specified delay. |
| 136 | * We check rtt BEFORE we usleep, otherwise |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 137 | * on localhost we'll have no writes done (!) |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 138 | * before we exceed (rather small) rtt */ |
| 139 | usleep(rtt_4/8); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 140 | open: |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 141 | diff = MONOTONIC_US() - start; |
| 142 | DMSG("write to port %u @%u", port, diff - start); |
| 143 | if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */ |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 144 | open_ports++; |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 145 | result_str = "open"; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 146 | break; |
| 147 | } |
| 148 | } |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 149 | DMSG("out of loop @%u", diff); |
| 150 | if (result_str) |
| 151 | printf("%5u" "\t" "tcp" "\t" "%s" "\t" "%s" "\n", |
| 152 | port, result_str, port_name(port)); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 153 | |
| 154 | /* Estimate new rtt - we don't want to wait entire timeout |
| 155 | * for each port. *4 allows for rise in net delay. |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 156 | * We increase rtt quickly (rtt_4*4), decrease slowly |
| 157 | * (diff is at least rtt_4/8, *4 == rtt_4/2) |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 158 | * because we don't want to accidentally miss ports. */ |
Denis Vlasenko | 715c16a | 2008-03-23 14:46:14 +0000 | [diff] [blame] | 159 | rtt_4 = diff * 4; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 160 | if (rtt_4 < min_rtt) |
| 161 | rtt_4 = min_rtt; |
| 162 | if (rtt_4 > timeout) |
| 163 | rtt_4 = timeout; |
| 164 | /* Clean up */ |
| 165 | close(s); |
| 166 | } |
| 167 | if (ENABLE_FEATURE_CLEAN_UP) free(lsap); |
| 168 | |
Denys Vlasenko | 327f550 | 2013-11-29 16:45:45 +0100 | [diff] [blame] | 169 | printf("%u closed, %u open, %u timed out (or blocked) ports\n", |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 170 | closed_ports, |
| 171 | open_ports, |
| 172 | nports - (closed_ports + open_ports)); |
| 173 | return EXIT_SUCCESS; |
| 174 | } |