From: Aron Xu Date: Mon, 13 Feb 2012 15:16:04 +0800 Subject: quit timer --- nc.1 | 10 ++++++++++ netcat.c | 50 +++++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 51 insertions(+), 9 deletions(-) --- a/nc.1 +++ b/nc.1 @@ -41,6 +41,7 @@ .Op Fl O Ar length .Op Fl P Ar proxy_username .Op Fl p Ar source_port +.Op Fl q Ar seconds .Op Fl s Ar source .Op Fl T Ar keyword .Op Fl V Ar rtable @@ -167,6 +168,15 @@ Proxy authentication is only supported f Specify the source port .Nm should use, subject to privilege restrictions and availability. +.It Fl q Ar seconds +after EOF on stdin, wait the specified number of +.Ar seconds +and then quit. If +.Ar seconds +is negative, wait forever (default). Specifying a non-negative +.Ar seconds +implies +.Fl N . .It Fl r Choose source and/or destination ports randomly instead of sequentially within a range or in the order that the system --- a/netcat.c +++ b/netcat.c @@ -139,6 +139,7 @@ int Nflag; /* shutdown() network soc int nflag; /* Don't do name look up */ char *Pflag; /* Proxy username */ char *pflag; /* Localport flag */ +int qflag = -1; /* Quit after some secs */ int rflag; /* Random ports flag */ char *sflag; /* Source Address */ int tflag; /* Telnet Emulation */ @@ -224,6 +225,8 @@ ssize_t fillbuf(int, unsigned char *, si static int connect_with_timeout(int fd, const struct sockaddr *sa, socklen_t salen, int ctimeout); +static void quit(); + int main(int argc, char *argv[]) { @@ -256,9 +259,9 @@ main(int argc, char *argv[]) while ((ch = getopt(argc, argv, # if defined(TLS) - "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) + "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:q:R:rSs:T:tUuV:vW:w:X:x:Z:z")) # else - "46CDdFhI:i:klM:m:NnO:P:p:rSs:T:tUuV:vW:w:X:x:z")) + "46CDdFhI:i:klM:m:NnO:P:p:q:rSs:T:tUuV:vW:w:X:x:z")) # endif != -1) { switch (ch) { @@ -350,6 +353,13 @@ main(int argc, char *argv[]) case 'p': pflag = optarg; break; + case 'q': + qflag = strtonum(optarg, INT_MIN, INT_MAX, &errstr); + if (errstr) + errx(1, "quit timer %s: %s", errstr, optarg); + if (qflag >= 0) + Nflag = 1; + break; # if defined(TLS) case 'R': tls_cachanged = 1; @@ -1319,15 +1329,27 @@ readwrite(int net_fd) while (1) { /* both inputs are gone, buffers are empty, we are done */ if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && - stdinbufpos == 0 && netinbufpos == 0) - return; + stdinbufpos == 0 && netinbufpos == 0) { + if (qflag <= 0) + return; + goto delay_exit; + } /* both outputs are gone, we can't continue */ - if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) - return; + if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { + if (qflag <= 0) + return; + goto delay_exit; + } /* listen and net in gone, queues empty, done */ if (lflag && pfd[POLL_NETIN].fd == -1 && - stdinbufpos == 0 && netinbufpos == 0) - return; + stdinbufpos == 0 && netinbufpos == 0) { + if (qflag <= 0) + return; +delay_exit: + close(net_fd); + signal(SIGALRM, quit); + alarm(qflag); + } /* poll */ num_fds = poll(pfd, 4, timeout); @@ -2052,6 +2074,7 @@ help(void) \t-O length TCP send buffer length\n\ \t-P proxyuser\tUsername for proxy authentication\n\ \t-p port\t Specify local port for remote connects\n\ + \t-q secs\t quit after EOF on stdin and delay of secs\n\ \t-r Randomize remote ports\n\ \t-S Enable the TCP MD5 signature option\n\ \t-s source Local source address\n\ @@ -2076,10 +2099,19 @@ usage(int ret) fprintf(stderr, "usage: nc [-46CDdFhklNnrStUuvz] [-I length] [-i interval] [-M ttl]\n" "\t [-m minttl] [-O length] [-P proxy_username] [-p source_port]\n" - "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " + "\t [-q seconds] [-s source] [-T keyword] [-V rtable] [-W recvlimit] " "[-w timeout]\n" "\t [-X proxy_protocol] [-x proxy_address[:port]] " "\t [destination] [port]\n"); if (ret) exit(1); } + +/* + * quit() + * handler for a "-q" timeout (exit 0 instead of 1) + */ +static void quit() +{ + exit(0); +}