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-rw-r--r--toys/net/netcat.c176
1 files changed, 76 insertions, 100 deletions
diff --git a/toys/net/netcat.c b/toys/net/netcat.c
index 1c75eb26..24420d6b 100644
--- a/toys/net/netcat.c
+++ b/toys/net/netcat.c
@@ -5,7 +5,7 @@
* TODO: udp, ipv6, genericize for telnet/microcom/tail-f
USE_NETCAT(OLDTOY(nc, netcat, TOYFLAG_USR|TOYFLAG_BIN))
-USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tlL")"w#p#s:q#f:", TOYFLAG_BIN))
+USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tlL")"w#W#p#s:q#f:"USE_NETCAT_LISTEN("[!tlL][!Lw]"), TOYFLAG_BIN))
config NETCAT
bool "netcat"
@@ -15,9 +15,10 @@ config NETCAT
-f use FILENAME (ala /dev/ttyS0) instead of network
-p local port number
- -q SECONDS quit this many seconds after EOF on stdin.
- -s local ipv4 address
- -w SECONDS timeout for connection
+ -q quit SECONDS after EOF on stdin, even if stdout hasn't closed yet.
+ -s local source address
+ -w SECONDS timeout to establish connection
+ -W SECONDS timeout for idle connection
Use "stty 115200 -F /dev/ttyS0 && stty raw -echo -ctlecho" with
netcat -f to connect to a serial port.
@@ -26,28 +27,20 @@ config NETCAT_LISTEN
bool "netcat server options (-let)"
default y
depends on NETCAT
- depends on TOYBOX_FORK
help
- usage: netcat [-lL COMMAND...]
+ usage: netcat [-t] [-lL COMMAND...]
- -l listen for one incoming connection.
- -L listen for multiple incoming connections (server mode).
+ -l listen for one incoming connection
+ -L listen for multiple incoming connections (server mode)
+ -t allocate tty (must come before -l or -L)
- The command line after -l or -L is executed to handle each incoming
- connection. If none, the connection is forwarded to stdin/stdout.
+ The command line after -l or -L is executed (as a child process) to handle
+ each incoming connection. If blank -l waits for a connection and forwards
+ it to stdin/stdout. If no -p specified, -l prints port it bound to and
+ backgrounds itself (returning immediately).
For a quick-and-dirty server, try something like:
netcat -s 127.0.0.1 -p 1234 -tL /bin/bash -l
-
-config NETCAT_LISTEN_TTY
- bool
- default y
- depends on NETCAT_LISTEN
- depends on TOYBOX_FORK
- help
- usage: netcat [-t]
-
- -t allocate tty (must come before -l or -L)
*/
#define FOR_netcat
@@ -58,6 +51,7 @@ GLOBALS(
long quit_delay; // -q Exit after EOF from stdin after # seconds.
char *source_address; // -s Bind to a specific source address.
long port; // -p Bind to a specific source port.
+ long idle; // -W Wait # seconds for more data
long wait; // -w Wait # seconds for a connection.
)
@@ -92,36 +86,34 @@ static void lookup_port(char *str, uint16_t *port)
void netcat_main(void)
{
- int sockfd=-1, pollcount=2;
- struct pollfd pollfds[2];
+ struct sockaddr_in *address = (void *)toybuf;
+ int sockfd=-1, in1 = 0, in2 = 0, out1 = 1, out2 = 1;
+ pid_t child;
+
+ // Addjust idle and quit_delay to miliseconds or -1 for no timeout
+ TT.idle = TT.idle ? TT.idle*1000 : -1;
+ TT.quit_delay = TT.quit_delay ? TT.quit_delay*1000 : -1;
- memset(pollfds, 0, 2*sizeof(struct pollfd));
- pollfds[0].events = pollfds[1].events = POLLIN;
set_alarm(TT.wait);
// The argument parsing logic can't make "<2" conditional on other
// arguments like -f and -l, so we do it by hand here.
if ((toys.optflags&FLAG_f) ? toys.optc :
(!(toys.optflags&(FLAG_l|FLAG_L)) && toys.optc!=2))
- help_exit("Argument count wrong");
+ help_exit("bad argument count");
- if (TT.filename) pollfds[0].fd = xopen(TT.filename, O_RDWR);
+ if (TT.filename) in1 = out2 = xopen(TT.filename, O_RDWR);
else {
- int temp;
- struct sockaddr_in address;
-
// Setup socket
sockfd = xsocket(AF_INET, SOCK_STREAM, 0);
fcntl(sockfd, F_SETFD, FD_CLOEXEC);
- temp = 1;
- setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &temp, sizeof(temp));
- memset(&address, 0, sizeof(address));
- address.sin_family = AF_INET;
+ setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &out1, sizeof(out1));
+ address->sin_family = AF_INET;
if (TT.source_address || TT.port) {
- address.sin_port = SWAP_BE16(TT.port);
+ address->sin_port = SWAP_BE16(TT.port);
if (TT.source_address)
- lookup_name(TT.source_address, (uint32_t *)&address.sin_addr);
- if (bind(sockfd, (struct sockaddr *)&address, sizeof(address)))
+ lookup_name(TT.source_address, (uint32_t *)&(address->sin_addr));
+ if (bind(sockfd, (struct sockaddr *)address, sizeof(*address)))
perror_exit("bind");
}
@@ -129,102 +121,86 @@ void netcat_main(void)
if (!CFG_NETCAT_LISTEN || !(toys.optflags&(FLAG_L|FLAG_l))) {
// Figure out where to dial out to.
- lookup_name(*toys.optargs, (uint32_t *)&address.sin_addr);
- lookup_port(toys.optargs[1], &address.sin_port);
- temp = connect(sockfd, (struct sockaddr *)&address, sizeof(address));
- if (temp<0) perror_exit("connect");
- pollfds[0].fd = sockfd;
+ lookup_name(*toys.optargs, (uint32_t *)&(address->sin_addr));
+ lookup_port(toys.optargs[1], &(address->sin_port));
+// TODO xconnect
+ if (connect(sockfd, (struct sockaddr *)address, sizeof(*address))<0)
+ perror_exit("connect");
+ in1 = out2 = sockfd;
// Listen for incoming connections
} else {
- socklen_t len = sizeof(address);
+ socklen_t len = sizeof(*address);
if (listen(sockfd, 5)) error_exit("listen");
if (!TT.port) {
- getsockname(sockfd, (struct sockaddr *)&address, &len);
- printf("%d\n", SWAP_BE16(address.sin_port));
+ getsockname(sockfd, (struct sockaddr *)address, &len);
+ printf("%d\n", SWAP_BE16(address->sin_port));
fflush(stdout);
- }
- // Do we need to return immediately because -l has arguments?
-
- if ((toys.optflags & FLAG_l) && toys.optc) {
- if (CFG_TOYBOX_FORK && xfork()) goto cleanup;
- close(0);
- close(1);
- close(2);
+ // Return immediately if no -p and -Ll has arguments, so wrapper
+ // script can use port number.
+ if (CFG_TOYBOX_FORK && toys.optc && xfork()) goto cleanup;
}
for (;;) {
- pid_t child = 0;
+ child = 0;
+ len = sizeof(*address); // gcc's insane optimizer can overwrite this
+ in1 = out2 = accept(sockfd, (struct sockaddr *)address, &len);
- // For -l, call accept from the _new_ process.
+ if (in1<0) perror_exit("accept");
- pollfds[0].fd = accept(sockfd, (struct sockaddr *)&address, &len);
- if (pollfds[0].fd<0) perror_exit("accept");
+ // We can't exit this loop or the optimizer's "liveness analysis"
+ // combines badly with vfork() to corrupt or local variables
+ // (the child's call stack gets trimmed and the next function call
+ // stops the variables the parent tries to re-use next loop)
+ // So there's a bit of redundancy here
- // Do we need a tty?
+ // We have a connection. Disarm timeout.
+ set_alarm(0);
- if (toys.optflags&FLAG_t)
- child = forkpty(&(pollfds[1].fd), NULL, NULL, NULL);
+ if (toys.optc) {
+ // Do we need a tty?
- // Do we need to fork and/or redirect for exec?
+// 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
+
+ // Do we need to fork and/or redirect for exec?
- else {
if (toys.optflags&FLAG_L) {
toys.stacktop = 0;
child = vfork();
}
- if (!child && toys.optc) {
- int fd = pollfds[0].fd;
-
- dup2(fd, 0);
- dup2(fd, 1);
- if (toys.optflags&FLAG_L) dup2(fd, 2);
- if (fd>2) close(fd);
+ if (child<0) error_msg("vfork failed\n");
+ else {
+ if (child) {
+ close(in1);
+ continue;
+ }
+ dup2(in1, 0);
+ dup2(in1, 1);
+ if (toys.optflags&FLAG_L) dup2(in1, 2);
+ if (in1>2) close(in1);
+ xexec(toys.optargs);
}
}
- if (child<0) error_msg("Fork failed\n");
- if (child<1) break;
- close(pollfds[0].fd);
+ pollinate(in1, in2, out1, out2, TT.idle, TT.quit_delay);
+ close(in1);
}
}
}
- // We have a connection. Disarm timeout.
- // (Does not play well with -L, but what _should_ that do?)
+ // We have a connection. Disarm timeout.
set_alarm(0);
- if (CFG_NETCAT_LISTEN && ((toys.optflags&(FLAG_L|FLAG_l)) && toys.optc))
- xexec(toys.optargs);
-
- // Poll loop copying stdin->socket and socket->stdout.
- for (;;) {
- int i;
-
- if (0>poll(pollfds, pollcount, -1)) perror_exit("poll");
-
- for (i=0; i<pollcount; i++) {
- if (pollfds[i].revents & POLLIN) {
- int len = read(pollfds[i].fd, toybuf, sizeof(toybuf));
- if (len<1) goto dohupnow;
- xwrite(i ? pollfds[0].fd : 1, toybuf, len);
- } else if (pollfds[i].revents & POLLHUP) {
-dohupnow:
- // Close half-connection. This is needed for things like
- // "echo GET / | netcat landley.net 80"
- if (i) {
- shutdown(pollfds[0].fd, SHUT_WR);
- pollcount--;
- set_alarm(TT.quit_delay);
- } else goto cleanup;
- }
- }
- }
+ pollinate(in1, in2, out1, out2, TT.idle, TT.quit_delay);
+
cleanup:
if (CFG_TOYBOX_FREE) {
- close(pollfds[0].fd);
+ close(in1);
close(sockfd);
}
}
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