*
* Copyright (C) 2007 Denys Vlasenko.
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
/* Author's comments from nc 1.10:
* - source routing
* - multiple DNS checks
* Functionalty which is different from nc 1.10:
- * - Prog in '-e prog' can have prog's parameters and options.
+ * - PROG in '-e PROG' can have ARGS (and options).
* Because of this -e option must be last.
- * - nc doesn't redirect stderr to the network socket for the -e prog.
+//TODO: remove -e incompatibility?
+ * - we don't redirect stderr to the network socket for the -e PROG.
+ * (PROG can do it itself if needed, but sometimes it is NOT wanted!)
* - numeric addresses are printed in (), not [] (IPv6 looks better),
* port numbers are inside (): (1.2.3.4:5678)
* - network read errors are reported on verbose levels > 1
* (nc 1.10 treats them as EOF)
* - TCP connects from wrong ip/ports (if peer ip:port is specified
* on the command line, but accept() says that it came from different addr)
- * are closed, but nc doesn't exit - continues to listen/accept.
+ * are closed, but we don't exit - we continue to listen/accept.
*/
/* done in nc.c: #include "libbb.h" */
+//usage:#if ENABLE_NC_110_COMPAT
+//usage:
+//usage:#define nc_trivial_usage
+//usage: "[OPTIONS] HOST PORT - connect"
+//usage: IF_NC_SERVER("\n"
+//usage: "nc [OPTIONS] -l -p PORT [HOST] [PORT] - listen")
+//usage:#define nc_full_usage "\n\n"
+//usage: "Options:"
+//usage: "\n -e PROG Run PROG after connect (must be last)"
+//usage: IF_NC_SERVER(
+//usage: "\n -l Listen mode, for inbound connects"
+//usage: )
+//usage: "\n -p PORT Local port"
+//usage: "\n -s ADDR Local address"
+//usage: "\n -w SEC Timeout for connects and final net reads"
+//usage: IF_NC_EXTRA(
+//usage: "\n -i SEC Delay interval for lines sent" /* ", ports scanned" */
+//usage: )
+//usage: "\n -n Don't do DNS resolution"
+//usage: "\n -u UDP mode"
+//usage: "\n -v Verbose"
+//usage: IF_NC_EXTRA(
+//usage: "\n -o FILE Hex dump traffic"
+//usage: "\n -z Zero-I/O mode (scanning)"
+//usage: )
+//usage:#endif
+
+/* "\n -r Randomize local and remote ports" */
+/* "\n -g gateway Source-routing hop point[s], up to 8" */
+/* "\n -G num Source-routing pointer: 4, 8, 12, ..." */
+/* "\nport numbers can be individual or ranges: lo-hi [inclusive]" */
+
+/* -e PROG can take ARGS too: "nc ... -e ls -l", but we don't document it
+ * in help text: nc 1.10 does not allow that. We don't want to entice
+ * users to use this incompatibility */
+
enum {
SLEAZE_PORT = 31337, /* for UDP-scan RTT trick, change if ya want */
BIGSIZ = 8192, /* big buffers */
unsigned wrote_out; /* total stdout bytes */
unsigned wrote_net; /* total net bytes */
#endif
- /* ouraddr is never NULL and goes thru three states as we progress:
+ /* ouraddr is never NULL and goes through three states as we progress:
1 - local address before bind (IP/port possibly zero)
2 - local address after bind (port is nonzero)
3 - local address after connect??/recv/accept (IP and port are nonzero) */
};
#define G (*ptr_to_globals)
-
#define wrote_out (G.wrote_out )
#define wrote_net (G.wrote_net )
#define ouraddr (G.ouraddr )
#else
#define o_interval 0
#endif
+#define INIT_G() do { \
+ SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
+} while (0)
+
/* Must match getopt32 call! */
enum {
/* Debug: squirt whatever message and sleep a bit so we can see it go by. */
/* Beware: writes to stdOUT... */
#if 0
-#define Debug(...) do { printf(__VA_ARGS__); printf("\n"); fflush(stdout); sleep(1); } while (0)
+#define Debug(...) do { printf(__VA_ARGS__); printf("\n"); fflush_all(); sleep(1); } while (0)
#else
#define Debug(...) do { } while (0)
#endif
if (o_verbose > 1) /* normally we don't care */
fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out);
fprintf(stderr, "punt!\n");
- exit(1);
+ kill_myself_with_sig(sig);
}
/* unarm */
}
/* timeout and other signal handling cruft */
-static void tmtravel(int sig)
+static void tmtravel(int sig UNUSED_PARAM)
{
unarm();
longjmp(jbuf, 1);
that would be security-critical, which is why it's ifdefed out by default.
Use at your own hairy risk; if you leave shells lying around behind open
listening ports you deserve to lose!! */
-static int doexec(char **proggie) ATTRIBUTE_NORETURN;
+static int doexec(char **proggie) NORETURN;
static int doexec(char **proggie)
{
xmove_fd(netfd, 0);
/* dup2(0, 2); - do we *really* want this? NO!
* exec'ed prog can do it yourself, if needed */
execvp(proggie[0], proggie);
- bb_perror_msg_and_die("exec");
+ bb_perror_msg_and_die("can't execute '%s'", proggie[0]);
}
/* connect_w_timeout:
random unknown port is probably not very useful without "netstat". */
if (o_verbose) {
char *addr;
- rr = getsockname(netfd, &ouraddr->u.sa, &ouraddr->len);
- if (rr < 0)
- bb_perror_msg_and_die("getsockname after bind");
+ getsockname(netfd, &ouraddr->u.sa, &ouraddr->len);
+ //if (rr < 0)
+ // bb_perror_msg_and_die("getsockname after bind");
addr = xmalloc_sockaddr2dotted(&ouraddr->u.sa);
fprintf(stderr, "listening on %s ...\n", addr);
free(addr);
rr = accept(netfd, &remend.u.sa, &remend.len);
if (rr < 0)
bb_perror_msg_and_die("accept");
- if (themaddr && memcmp(&remend.u.sa, &themaddr->u.sa, remend.len) != 0) {
- /* nc 1.10 bails out instead, and its error message
- * is not suppressed by o_verbose */
- if (o_verbose) {
- char *remaddr = xmalloc_sockaddr2dotted(&remend.u.sa);
- bb_error_msg("connect from wrong ip/port %s ignored", remaddr);
- free(remaddr);
+ if (themaddr) {
+ int sv_port, port, r;
+
+ sv_port = get_nport(&remend.u.sa); /* save */
+ port = get_nport(&themaddr->u.sa);
+ if (port == 0) {
+ /* "nc -nl -p LPORT RHOST" (w/o RPORT!):
+ * we should accept any remote port */
+ set_nport(&remend, 0); /* blot out remote port# */
+ }
+ r = memcmp(&remend.u.sa, &themaddr->u.sa, remend.len);
+ set_nport(&remend, sv_port); /* restore */
+ if (r != 0) {
+ /* nc 1.10 bails out instead, and its error message
+ * is not suppressed by o_verbose */
+ if (o_verbose) {
+ char *remaddr = xmalloc_sockaddr2dotted(&remend.u.sa);
+ bb_error_msg("connect from wrong ip/port %s ignored", remaddr);
+ free(remaddr);
+ }
+ close(rr);
+ goto again;
}
- close(rr);
- goto again;
}
unarm();
} else
doing a listen-on-any on a multihomed machine. This allows one to
offer different services via different alias addresses, such as the
"virtual web site" hack. */
- rr = getsockname(netfd, &ouraddr->u.sa, &ouraddr->len);
- if (rr < 0)
- bb_perror_msg_and_die("getsockname after accept");
+ getsockname(netfd, &ouraddr->u.sa, &ouraddr->len);
+ //if (rr < 0)
+ // bb_perror_msg_and_die("getsockname after accept");
}
if (o_verbose) {
thing to emerge after all the intervening crud. Doesn't work for UDP on
any machines I've tested, but feel free to surprise me. */
char optbuf[40];
- int x = sizeof(optbuf);
+ socklen_t x = sizeof(optbuf);
rr = getsockopt(netfd, IPPROTO_IP, IP_OPTIONS, optbuf, &x);
- if (rr < 0)
- bb_perror_msg("getsockopt failed");
- else if (x) { /* we've got options, lessee em... */
+ if (rr >= 0 && x) { /* we've got options, lessee em... */
bin2hex(bigbuf_net, optbuf, x);
bigbuf_net[2*x] = '\0';
fprintf(stderr, "IP options: %s\n", bigbuf_net);
memset(&stage[11], ' ', 16*3);
x = bc;
}
- sprintf(&stage[1], " %8.8x ", obc); /* xxx: still slow? */
+ sprintf((char *)&stage[1], " %8.8x ", obc); /* xxx: still slow? */
bc -= x; /* fix current count */
obc += x; /* fix current offset */
op = &stage[11]; /* where hex starts */
/* if we have a timeout AND stdin is closed AND we haven't heard anything
from the net during that time, assume it's dead and close it too. */
if (rr == 0) {
- if (!FD_ISSET(0, &ding1))
+ if (!FD_ISSET(STDIN_FILENO, &ding1))
netretry--; /* we actually try a coupla times. */
if (!netretry) {
if (o_verbose > 1) /* normally we don't care */
goto shovel;
/* okay, suck more stdin */
- if (FD_ISSET(0, &ding2)) { /* stdin: ding! */
- rr = read(0, bigbuf_in, BIGSIZ);
+ if (FD_ISSET(STDIN_FILENO, &ding2)) { /* stdin: ding! */
+ rr = read(STDIN_FILENO, bigbuf_in, BIGSIZ);
/* Considered making reads here smaller for UDP mode, but 8192-byte
mobygrams are kinda fun and exercise the reassembler. */
if (rr <= 0) { /* at end, or fukt, or ... */
- FD_CLR(0, &ding1); /* disable and close stdin */
- close(0);
+ FD_CLR(STDIN_FILENO, &ding1); /* disable and close stdin */
+ close(STDIN_FILENO);
+// Does it make sense to shutdown(net_fd, SHUT_WR)
+// to let other side know that we won't write anything anymore?
+// (and what about keeping compat if we do that?)
} else {
rzleft = rr;
zp = bigbuf_in;
return 1;
}
if (rnleft) {
- rr = write(1, np, rnleft);
+ rr = write(STDOUT_FILENO, np, rnleft);
if (rr > 0) {
- if (o_ofile)
- oprint('<', np, rr); /* log the stdout */
+ if (o_ofile) /* log the stdout */
+ oprint('<', (unsigned char *)np, rr);
np += rr; /* fix up ptrs and whatnot */
rnleft -= rr; /* will get sanity-checked above */
wrote_out += rr; /* global count */
rr = rzleft;
rr = write(netfd, zp, rr); /* one line, or the whole buffer */
if (rr > 0) {
- if (o_ofile)
- oprint('>', zp, rr); /* log what got sent */
+ if (o_ofile) /* log what got sent */
+ oprint('>', (unsigned char *)zp, rr);
zp += rr;
rzleft -= rr;
wrote_net += rr; /* global count */
/* main: now we pull it all together... */
int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int nc_main(int argc, char **argv)
+int nc_main(int argc UNUSED_PARAM, char **argv)
{
- char *str_p, *str_s, *str_w;
- USE_NC_EXTRA(char *str_i, *str_o;)
+ char *str_p, *str_s;
+ IF_NC_EXTRA(char *str_i, *str_o;)
char *themdotted = themdotted; /* gcc */
char **proggie;
int x;
unsigned o_lport = 0;
- /* I was in this barbershop quartet in Skokie IL ... */
- /* round up the usual suspects, i.e. malloc up all the stuff we need */
- PTR_TO_GLOBALS = xzalloc(sizeof(G));
+ INIT_G();
/* catch a signal or two for cleanup */
- signal(SIGINT, catch);
- signal(SIGQUIT, catch);
- signal(SIGTERM, catch);
+ bb_signals(0
+ + (1 << SIGINT)
+ + (1 << SIGQUIT)
+ + (1 << SIGTERM)
+ , catch);
/* and suppress others... */
+ bb_signals(0
#ifdef SIGURG
- signal(SIGURG, SIG_IGN);
+ + (1 << SIGURG)
#endif
- signal(SIGPIPE, SIG_IGN); /* important! */
+ + (1 << SIGPIPE) /* important! */
+ , SIG_IGN);
proggie = argv;
while (*++proggie) {
if (strcmp(*proggie, "-e") == 0) {
*proggie = NULL;
- argc = proggie - argv;
proggie++;
goto e_found;
}
e_found:
// -g -G -t -r deleted, unimplemented -a deleted too
- opt_complementary = "?2:vv"; /* max 2 params, -v is a counter */
- getopt32(argv, "hnp:s:uvw:" USE_NC_SERVER("l")
- USE_NC_EXTRA("i:o:z"),
- &str_p, &str_s, &str_w
- USE_NC_EXTRA(, &str_i, &str_o, &o_verbose));
+ opt_complementary = "?2:vv:w+"; /* max 2 params; -v is a counter; -w N */
+ getopt32(argv, "hnp:s:uvw:" IF_NC_SERVER("l")
+ IF_NC_EXTRA("i:o:z"),
+ &str_p, &str_s, &o_wait
+ IF_NC_EXTRA(, &str_i, &str_o, &o_verbose));
argv += optind;
#if ENABLE_NC_EXTRA
if (option_mask32 & OPT_i) /* line-interval time */
//if (option_mask32 & OPT_r) /* randomize various things */
//if (option_mask32 & OPT_u) /* use UDP */
//if (option_mask32 & OPT_v) /* verbose */
- if (option_mask32 & OPT_w) { /* wait time */
- o_wait = xatoi_u(str_w);
- }
+ //if (option_mask32 & OPT_w) /* wait time */
//if (option_mask32 & OPT_z) /* little or no data xfer */
/* We manage our fd's so that they are never 0,1,2 */
if (option_mask32 & OPT_s) { /* local address */
/* if o_lport is still 0, then we will use random port */
ouraddr = xhost2sockaddr(str_s, o_lport);
+#ifdef BLOAT
+ /* prevent spurious "UDP listen needs !0 port" */
+ o_lport = get_nport(ouraddr);
+ o_lport = ntohs(o_lport);
+#endif
x = xsocket(ouraddr->u.sa.sa_family, x, 0);
} else {
/* We try IPv6, then IPv4, unless addr family is
* implicitly set by way of remote addr/port spec */
x = xsocket_type(&ouraddr,
- USE_FEATURE_IPV6((themaddr ? themaddr->u.sa.sa_family : AF_UNSPEC),)
+ (themaddr ? themaddr->u.sa.sa_family : AF_UNSPEC),
x);
if (o_lport)
set_nport(ouraddr, htons(o_lport));
setsockopt_reuseaddr(netfd);
if (o_udpmode)
socket_want_pktinfo(netfd);
- xbind(netfd, &ouraddr->u.sa, ouraddr->len);
+ if (!ENABLE_FEATURE_UNIX_LOCAL
+ || o_listen
+ || ouraddr->u.sa.sa_family != AF_UNIX
+ ) {
+ xbind(netfd, &ouraddr->u.sa, ouraddr->len);
+ }
#if 0
setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &o_rcvbuf, sizeof o_rcvbuf);
setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf);
#endif
+#ifdef BLOAT
if (OPT_l && (option_mask32 & (OPT_u|OPT_l)) == (OPT_u|OPT_l)) {
/* apparently UDP can listen ON "port 0",
but that's not useful */
if (!o_lport)
bb_error_msg_and_die("UDP listen needs nonzero -p port");
}
+#endif
- FD_SET(0, &ding1); /* stdin *is* initially open */
+ FD_SET(STDIN_FILENO, &ding1); /* stdin *is* initially open */
if (proggie) {
close(0); /* won't need stdin */
option_mask32 &= ~OPT_o; /* -o with -e is meaningless! */
} else {
/* Outbound connects. Now we're more picky about args... */
if (!themaddr)
- bb_error_msg_and_die("no destination");
+ bb_show_usage();
remend = *themaddr;
if (o_verbose)
projects / oweals / busybox.git / blobdiff