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 | * |
| 6 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
| 7 | */ |
| 8 | |
| 9 | #include "libbb.h" |
| 10 | |
| 11 | /* debugging */ |
| 12 | #ifdef DEBUG_PSCAN |
| 13 | #define DMSG(...) bb_error_msg(__VA_ARGS__) |
| 14 | #define DERR(...) bb_perror_msg(__VA_ARGS__) |
| 15 | #else |
| 16 | #define DMSG(...) ((void)0) |
| 17 | #define DERR(...) ((void)0) |
| 18 | #endif |
| 19 | |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 20 | static const char *port_name(unsigned port) |
| 21 | { |
| 22 | struct servent *server; |
| 23 | |
| 24 | server = getservbyport(htons(port), NULL); |
| 25 | if (server) |
| 26 | return server->s_name; |
| 27 | return "unknown"; |
| 28 | } |
| 29 | |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 30 | /* We don't expect to see 1000+ seconds delay, unsigned is enough */ |
| 31 | #define MONOTONIC_US() ((unsigned)monotonic_us()) |
| 32 | |
Denis Vlasenko | 9b49a5e | 2007-10-11 10:05:36 +0000 | [diff] [blame] | 33 | int pscan_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
Denis Vlasenko | 68404f1 | 2008-03-17 09:00:54 +0000 | [diff] [blame^] | 34 | int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 35 | { |
| 36 | const char *opt_max_port = "1024"; /* -P: default max port */ |
| 37 | const char *opt_min_port = "1"; /* -p: default min port */ |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 38 | const char *opt_timeout = "5000"; /* -t: default timeout in msec */ |
Denis Vlasenko | 49a128a | 2007-07-17 21:42:59 +0000 | [diff] [blame] | 39 | /* We estimate rtt and wait rtt*4 before concluding that port is |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 40 | * totally blocked. min rtt of 5 ms may be too low if you are |
| 41 | * scanning an Internet host behind saturated/traffic shaped link. |
| 42 | * Rule of thumb: with min_rtt of N msec, scanning 1000 ports |
| 43 | * will take N seconds at absolute minimum */ |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 44 | const char *opt_min_rtt = "5"; /* -T: default min rtt in msec */ |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 45 | len_and_sockaddr *lsap; |
| 46 | int s; |
| 47 | unsigned port, max_port, nports; |
| 48 | unsigned closed_ports = 0; |
| 49 | unsigned open_ports = 0; |
| 50 | /* all in usec */ |
| 51 | unsigned timeout; |
| 52 | unsigned min_rtt; |
| 53 | unsigned rtt_4; |
| 54 | unsigned start; |
| 55 | |
| 56 | opt_complementary = "=1"; /* exactly one non-option */ |
Denis Vlasenko | fe7cd64 | 2007-08-18 15:32:12 +0000 | [diff] [blame] | 57 | getopt32(argv, "p: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] | 58 | argv += optind; |
| 59 | max_port = xatou_range(opt_max_port, 1, 65535); |
Denis Vlasenko | dcf6de5 | 2007-06-19 16:57:47 +0000 | [diff] [blame] | 60 | port = xatou_range(opt_min_port, 1, max_port); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 61 | nports = max_port - port + 1; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 62 | rtt_4 = timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000; |
| 63 | min_rtt = xatou_range(opt_min_rtt, 1, INT_MAX/1000 / 4) * 1000; |
| 64 | |
| 65 | DMSG("min_rtt %u timeout %u", min_rtt, timeout); |
| 66 | |
| 67 | lsap = xhost2sockaddr(*argv, port); |
| 68 | printf("Scanning %s ports %u to %u\n Port\tProto\tState\tService\n", |
| 69 | *argv, port, max_port); |
| 70 | |
| 71 | for (; port <= max_port; port++) { |
| 72 | DMSG("rtt %u", rtt_4); |
| 73 | |
| 74 | /* The SOCK_STREAM socket type is implemented on the TCP/IP protocol. */ |
| 75 | set_nport(lsap, htons(port)); |
Bernhard Reutner-Fischer | 8c69afd | 2008-01-29 10:33:34 +0000 | [diff] [blame] | 76 | s = xsocket(lsap->u.sa.sa_family, SOCK_STREAM, 0); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 77 | |
| 78 | /* We need unblocking socket so we don't need to wait for ETIMEOUT. */ |
| 79 | /* Nonblocking connect typically "fails" with errno == EINPROGRESS */ |
| 80 | ndelay_on(s); |
| 81 | DMSG("connect to port %u", port); |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 82 | start = MONOTONIC_US(); |
Bernhard Reutner-Fischer | 8c69afd | 2008-01-29 10:33:34 +0000 | [diff] [blame] | 83 | if (connect(s, &lsap->u.sa, lsap->len) == 0) { |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 84 | /* Unlikely, for me even localhost fails :) */ |
| 85 | DMSG("connect succeeded"); |
| 86 | goto open; |
| 87 | } |
| 88 | /* Check for untypical errors... */ |
| 89 | if (errno != EAGAIN && errno != EINPROGRESS |
| 90 | && errno != ECONNREFUSED |
| 91 | ) { |
| 92 | bb_perror_nomsg_and_die(); |
| 93 | } |
| 94 | |
| 95 | while (1) { |
| 96 | if (errno == ECONNREFUSED) { |
| 97 | DMSG("port %u: ECONNREFUSED", port); |
| 98 | closed_ports++; |
| 99 | break; |
| 100 | } |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 101 | DERR("port %u errno %d @%u", port, errno, MONOTONIC_US() - start); |
| 102 | if ((MONOTONIC_US() - start) > rtt_4) |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 103 | break; |
| 104 | /* Can sleep (much) longer than specified delay. |
| 105 | * We check rtt BEFORE we usleep, otherwise |
| 106 | * on localhost we'll do zero writes done (!) |
| 107 | * before we exceed (rather small) rtt */ |
| 108 | usleep(rtt_4/8); |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 109 | DMSG("write to port %u @%u", port, MONOTONIC_US() - start); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 110 | if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */ |
| 111 | open: |
| 112 | open_ports++; |
| 113 | printf("%5u\ttcp\topen\t%s\n", port, port_name(port)); |
| 114 | break; |
| 115 | } |
| 116 | } |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 117 | DMSG("out of loop @%u", MONOTONIC_US() - start); |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 118 | |
| 119 | /* Estimate new rtt - we don't want to wait entire timeout |
| 120 | * for each port. *4 allows for rise in net delay. |
| 121 | * We increase rtt quickly (*4), decrease slowly (4/8 == 1/2) |
| 122 | * because we don't want to accidentally miss ports. */ |
Denis Vlasenko | 459be35 | 2007-06-17 19:09:05 +0000 | [diff] [blame] | 123 | rtt_4 = (MONOTONIC_US() - start) * 4; |
Denis Vlasenko | ab47eee | 2007-06-16 20:52:33 +0000 | [diff] [blame] | 124 | if (rtt_4 < min_rtt) |
| 125 | rtt_4 = min_rtt; |
| 126 | if (rtt_4 > timeout) |
| 127 | rtt_4 = timeout; |
| 128 | /* Clean up */ |
| 129 | close(s); |
| 130 | } |
| 131 | if (ENABLE_FEATURE_CLEAN_UP) free(lsap); |
| 132 | |
| 133 | printf("%d closed, %d open, %d timed out ports\n", |
| 134 | closed_ports, |
| 135 | open_ports, |
| 136 | nports - (closed_ports + open_ports)); |
| 137 | return EXIT_SUCCESS; |
| 138 | } |