715c16ab0
Denis Vlasenko
2008-03-23
Subject
pscan: add -c, -b: report closed, blocked ports
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include/usage.h+3 -1
| @@ -3019,10 +3019,12 @@ | |
| " 2990 andersen andersen R ps\n" | |
| #define pscan_trivial_usage \ | |
| - | "[-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT] HOST" |
| + | "[-cb] [-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT] HOST" |
| #define pscan_full_usage \ | |
| "Scan a host, print all open ports\n" \ | |
| "\nOptions:" \ | |
| + | "\n -c Show closed ports too" \ |
| + | "\n -c Show blocked ports too" \ |
| "\n -p Scan from this port (default 1)" \ | |
| "\n -P Scan up to this port (default 1024)" \ | |
| "\n -t Timeout (default 5000 ms)" \ | |
networking/pscan.c+31 -15
| @@ -42,8 +42,10 @@ int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| * Rule of thumb: with min_rtt of N msec, scanning 1000 ports | |
| * will take N seconds at absolute minimum */ | |
| const char *opt_min_rtt = "5"; /* -T: default min rtt in msec */ | |
| + | const char *result_str; |
| len_and_sockaddr *lsap; | |
| int s; | |
| + | unsigned opt; |
| unsigned port, max_port, nports; | |
| unsigned closed_ports = 0; | |
| unsigned open_ports = 0; | |
| @@ -51,16 +53,18 @@ int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| unsigned timeout; | |
| unsigned min_rtt; | |
| unsigned rtt_4; | |
| - | unsigned start; |
| + | unsigned start, diff; |
| opt_complementary = "=1"; /* exactly one non-option */ | |
| - | getopt32(argv, "p:P:t:T:", &opt_min_port, &opt_max_port, &opt_timeout, &opt_min_rtt); |
| + | opt = getopt32(argv, "cbp:P:t:T:", &opt_min_port, &opt_max_port, &opt_timeout, &opt_min_rtt); |
| argv += optind; | |
| max_port = xatou_range(opt_max_port, 1, 65535); | |
| port = xatou_range(opt_min_port, 1, max_port); | |
| nports = max_port - port + 1; | |
| - | rtt_4 = timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000; |
| min_rtt = xatou_range(opt_min_rtt, 1, INT_MAX/1000 / 4) * 1000; | |
| + | timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000; |
| + | /* Initial rtt is BIG: */ |
| + | rtt_4 = timeout; |
| DMSG("min_rtt %u timeout %u", min_rtt, timeout); | |
| @@ -74,11 +78,12 @@ int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| /* The SOCK_STREAM socket type is implemented on the TCP/IP protocol. */ | |
| set_nport(lsap, htons(port)); | |
| s = xsocket(lsap->u.sa.sa_family, SOCK_STREAM, 0); | |
| - | |
| /* We need unblocking socket so we don't need to wait for ETIMEOUT. */ | |
| /* Nonblocking connect typically "fails" with errno == EINPROGRESS */ | |
| ndelay_on(s); | |
| + | |
| DMSG("connect to port %u", port); | |
| + | result_str = NULL; |
| start = MONOTONIC_US(); | |
| if (connect(s, &lsap->u.sa, lsap->len) == 0) { | |
| /* Unlikely, for me even localhost fails :) */ | |
| @@ -92,35 +97,46 @@ int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| bb_perror_nomsg_and_die(); | |
| } | |
| + | diff = 0; |
| while (1) { | |
| if (errno == ECONNREFUSED) { | |
| - | DMSG("port %u: ECONNREFUSED", port); |
| + | if (opt & 1) /* -c: show closed too */ |
| + | result_str = "closed"; |
| closed_ports++; | |
| break; | |
| } | |
| - | DERR("port %u errno %d @%u", port, errno, MONOTONIC_US() - start); |
| - | if ((MONOTONIC_US() - start) > rtt_4) |
| + | DERR("port %u errno %d @%u", port, errno, diff); |
| + | |
| + | if (diff > rtt_4) { |
| + | if (opt & 2) /* -b: show blocked too */ |
| + | result_str = "blocked"; |
| break; | |
| + | } |
| /* Can sleep (much) longer than specified delay. | |
| * We check rtt BEFORE we usleep, otherwise | |
| - | * on localhost we'll do zero writes done (!) |
| + | * on localhost we'll have no writes done (!) |
| * before we exceed (rather small) rtt */ | |
| usleep(rtt_4/8); | |
| - | DMSG("write to port %u @%u", port, MONOTONIC_US() - start); |
| - | if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */ |
| open: | |
| + | diff = MONOTONIC_US() - start; |
| + | DMSG("write to port %u @%u", port, diff - start); |
| + | if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */ |
| open_ports++; | |
| - | printf("%5u\ttcp\topen\t%s\n", port, port_name(port)); |
| + | result_str = "open"; |
| break; | |
| } | |
| } | |
| - | DMSG("out of loop @%u", MONOTONIC_US() - start); |
| + | DMSG("out of loop @%u", diff); |
| + | if (result_str) |
| + | printf("%5u" "\t" "tcp" "\t" "%s" "\t" "%s" "\n", |
| + | port, result_str, port_name(port)); |
| /* Estimate new rtt - we don't want to wait entire timeout | |
| * for each port. *4 allows for rise in net delay. | |
| - | * We increase rtt quickly (*4), decrease slowly (4/8 == 1/2) |
| + | * We increase rtt quickly (rtt_4*4), decrease slowly |
| + | * (diff is at least rtt_4/8, *4 == rtt_4/2) |
| * because we don't want to accidentally miss ports. */ | |
| - | rtt_4 = (MONOTONIC_US() - start) * 4; |
| + | rtt_4 = diff * 4; |
| if (rtt_4 < min_rtt) | |
| rtt_4 = min_rtt; | |
| if (rtt_4 > timeout) | |
| @@ -130,7 +146,7 @@ int pscan_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| } | |
| if (ENABLE_FEATURE_CLEAN_UP) free(lsap); | |
| - | printf("%d closed, %d open, %d timed out ports\n", |
| + | printf("%d closed, %d open, %d timed out (or blocked) ports\n", |
| closed_ports, | |
| open_ports, | |
| nports - (closed_ports + open_ports)); | |