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-rw-r--r--toys/net/netcat.c107
1 files changed, 50 insertions, 57 deletions
diff --git a/toys/net/netcat.c b/toys/net/netcat.c
index 2d80a18f..38348949 100644
--- a/toys/net/netcat.c
+++ b/toys/net/netcat.c
@@ -2,47 +2,35 @@
*
* Copyright 2007 Rob Landley <rob@landley.net>
*
- * TODO: udp, ipv6, genericize for telnet/microcom/tail-f
- * fix -t, xconnect
- * netcat -L zombies
+ * TODO: genericize for telnet/microcom/tail-f, fix -t
+USE_NETCAT(NEWTOY(netcat, "^tElLw#<1W#<1p#<1>65535q#<1s:f:46uUn[!tlL][!Lw][!Lu][!46U]", TOYFLAG_BIN))
USE_NETCAT(OLDTOY(nc, netcat, TOYFLAG_USR|TOYFLAG_BIN))
-USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tElL")"w#<1W#<1p#<1>65535q#<1s:f:46uU"USE_NETCAT_LISTEN("[!tlL][!Lw]")"[!46U]", TOYFLAG_BIN))
config NETCAT
bool "netcat"
default y
help
- usage: netcat [-46U] [-u] [-wpq #] [-s addr] {IPADDR PORTNUM|-f FILENAME|COMMAND...}
+ usage: netcat [-46ElLtUu] [-wpq #] [-s addr] {IPADDR PORTNUM|-f FILENAME|COMMAND...}
Forward stdin/stdout to a file or network connection.
-4 Force IPv4
-6 Force IPv6
+ -E Forward stderr
-f Use FILENAME (ala /dev/ttyS0) instead of network
+ -l Listen for one incoming connection, then exit
+ -L Listen and background each incoming connection (server mode)
+ -n No DNS lookup
-p Local port number
-q Quit SECONDS after EOF on stdin, even if stdout hasn't closed yet
-s Local source address
+ -t Allocate tty
-u Use UDP
-U Use a UNIX domain socket
-w SECONDS timeout to establish connection
-W SECONDS timeout for more data on an idle connection
- Use "stty 115200 -F /dev/ttyS0 && stty raw -echo -ctlecho" with
- netcat -f to connect to a serial port.
-
-config NETCAT_LISTEN
- bool "netcat server options (-let)"
- default y
- depends on NETCAT
- help
- usage: netcat [-tElL]
-
- -l Listen for one incoming connection, then exit
- -L Listen and background each incoming connection (server mode)
- -t Allocate tty
- -E Forward stderr
-
When listening the COMMAND line is executed as a child process to handle
an incoming connection. With no COMMAND -l forwards the connection
to stdin/stdout. If no -p specified, -l prints the port it bound to and
@@ -50,6 +38,9 @@ config NETCAT_LISTEN
For a quick-and-dirty server, try something like:
netcat -s 127.0.0.1 -p 1234 -tL sh -l
+
+ Or use "stty 115200 -F /dev/ttyS0 && stty raw -echo -ctlecho" with
+ netcat -f to connect to a serial port.
*/
#define FOR_netcat
@@ -66,12 +57,6 @@ static void timeout(int signum)
xexit();
}
-static void set_alarm(int seconds)
-{
- xsignal(SIGALRM, seconds ? timeout : SIG_DFL);
- alarm(seconds);
-}
-
// open AF_UNIX socket
static int usock(char *name, int type, int out)
{
@@ -90,12 +75,12 @@ static int usock(char *name, int type, int out)
return sockfd;
}
-
void netcat_main(void)
{
int sockfd = -1, in1 = 0, in2 = 0, out1 = 1, out2 = 1, family = AF_UNSPEC,
- ll = FLAG(L)|FLAG(l), type = FLAG(u) ? SOCK_DGRAM : SOCK_STREAM;
+ type = FLAG(u) ? SOCK_DGRAM : SOCK_STREAM;
+ socklen_t len;
pid_t child;
// Addjust idle and quit_delay to ms or -1 for no timeout
@@ -103,11 +88,14 @@ void netcat_main(void)
TT.q = TT.q ? TT.q*1000 : -1;
xsignal(SIGCHLD, SIG_IGN);
- set_alarm(TT.w);
+ if (TT.w) {
+ xsignal(SIGALRM, timeout);
+ alarm(TT.w);
+ }
// The argument parsing logic can't make "<2" conditional on other
// arguments like -f and -l, so do it by hand here.
- if (FLAG(f) ? toys.optc : (!ll && toys.optc!=(FLAG(U)?1:2)))
+ if (FLAG(f) ? toys.optc : (!FLAG(l) && !FLAG(L) && toys.optc!=2-FLAG(U)))
help_exit("bad argument count");
if (FLAG(4)) family = AF_INET;
@@ -117,13 +105,13 @@ void netcat_main(void)
if (TT.f) in1 = out2 = xopen(TT.f, O_RDWR);
else {
// Setup socket
- if (!ll) {
+ if (!FLAG(l) && !FLAG(L)) {
if (FLAG(U)) sockfd = usock(toys.optargs[0], type, 1);
- else sockfd = xconnectany(xgetaddrinfo(toys.optargs[0], toys.optargs[1],
- family, type, 0, 0));
+ else sockfd = xconnectany(xgetaddrinfo(toys.optargs[0],
+ toys.optargs[1], family, type, 0, AI_NUMERICHOST*FLAG(n)));
// We have a connection. Disarm timeout and start poll/send loop.
- set_alarm(0);
+ alarm(0);
in1 = out2 = sockfd;
pollinate(in1, in2, out1, out2, TT.W, TT.q);
} else {
@@ -136,12 +124,12 @@ void netcat_main(void)
sockfd = xbindany(xgetaddrinfo(TT.s, toybuf, family, type, 0, 0));
}
- if (listen(sockfd, 5)) error_exit("listen");
+ if (!FLAG(u) && listen(sockfd, 5)) perror_exit("listen");
if (!TT.p && !FLAG(U)) {
struct sockaddr* address = (void*)toybuf;
- socklen_t len = sizeof(struct sockaddr_storage);
short port_be;
+ len = sizeof(struct sockaddr_storage);
getsockname(sockfd, address, &len);
if (address->sa_family == AF_INET)
port_be = ((struct sockaddr_in*)address)->sin_port;
@@ -156,41 +144,46 @@ void netcat_main(void)
}
do {
+ len = sizeof(struct sockaddr_storage);
+ if (FLAG(u)) {
+ if (-1 == recvfrom(in1 = dup(sockfd), &child, 1, MSG_PEEK,
+ (void *)toybuf, &len)) perror_exit("recvfrom");
+ } else if ((in1 = accept(sockfd, 0, 0))<0) perror_exit("accept");
+ out2 = in1;
child = 0;
- in1 = out2 = accept(sockfd, 0, 0);
- if (in1<0) perror_exit("accept");
// We have a connection. Disarm timeout.
- set_alarm(0);
-
- if (toys.optc) {
- // Do we need a tty?
+ alarm(0);
-// TODO nommu, and -t only affects server mode...? Only do -t with optc
-// if (CFG_TOYBOX_FORK && (toys.optflags&FLAG_t))
-// child = forkpty(&fdout, NULL, NULL, NULL);
-// else
+ // Fork a child as necessary. Parent cleans up and continues here.
+ if (toys.optc && FLAG(L)) NOEXIT(child = XVFORK());
+ if (child) {
+ close(in1);
+ continue;
+ }
- // Do we need to fork and/or redirect for exec?
+ if (FLAG(u))
+ xconnect(in1, (void *)toybuf, sizeof(struct sockaddr_storage));
-// TODO xpopen_both() here?
+ // Cleanup and redirect for exec
+ if (toys.optc) {
+ // Do we need a tty?
+// TODO nommu and -t only affects server mode...
+// if (FLAG(t)) child = forkpty(&fdout, NULL, NULL, NULL);
- if (FLAG(L)) NOEXIT(child = XVFORK());
- if (child) {
- close(in1);
- continue;
- }
close(sockfd);
dup2(in1, 0);
dup2(in1, 1);
if (FLAG(E)) dup2(in1, 2);
if (in1>2) close(in1);
xexec(toys.optargs);
- }
- pollinate(in1, in2, out1, out2, TT.W, TT.q);
- close(in1);
- } while (!FLAG(l));
+ // Copy stdin/out
+ } else {
+ pollinate(in1, in2, out1, out2, TT.W, TT.q);
+ close(in1);
+ }
+ } while (FLAG(L));
}
}