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authorRob Landley <rob@landley.net>2018-03-31 19:39:46 -0500
committerRob Landley <rob@landley.net>2018-03-31 19:39:46 -0500
commit96c0084bca9ef179e6e19fc77d8d67ebc1b8088b (patch)
tree4711f477aee843040274ea8976d3e4d7ea0a428d /toys
parente16c181f5869db5148410af39719128ec925923b (diff)
downloadtoybox-96c0084bca9ef179e6e19fc77d8d67ebc1b8088b.tar.gz
Use XVFORK() macro, add option ranges, make lookup_port() check /etc/services,
remove redundant CLOEXEC (xsocket does it) and CFG_NETCAT_LISTEN test (we're not doing FORCE_FLAGS so FLAG_L and FLAG_l become zero), remove comments about vfork triggering compiler/libc bugs (XVFORK handles it).
Diffstat (limited to 'toys')
-rw-r--r--toys/net/netcat.c55
1 files changed, 26 insertions, 29 deletions
diff --git a/toys/net/netcat.c b/toys/net/netcat.c
index 795f7b3c..cabc7e80 100644
--- a/toys/net/netcat.c
+++ b/toys/net/netcat.c
@@ -3,9 +3,11 @@
* Copyright 2007 Rob Landley <rob@landley.net>
*
* TODO: udp, ipv6, genericize for telnet/microcom/tail-f
+ * fix -t, xconnect
+ * netcat -L zombies
USE_NETCAT(OLDTOY(nc, netcat, TOYFLAG_USR|TOYFLAG_BIN))
-USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tlL")"w#W#p#s:q#f:"USE_NETCAT_LISTEN("[!tlL][!Lw]"), TOYFLAG_BIN))
+USE_NETCAT(NEWTOY(netcat, USE_NETCAT_LISTEN("^tlL")"w#<1W#<1p#<1>65535s:q#<1f:"USE_NETCAT_LISTEN("[!tlL][!Lw]"), TOYFLAG_BIN))
config NETCAT
bool "netcat"
@@ -79,9 +81,18 @@ static void lookup_name(char *name, uint32_t *result)
}
// Worry about a fancy lookup later.
-static void lookup_port(char *str, uint16_t *port)
+static unsigned short lookup_port(char *str)
{
- *port = SWAP_BE16(atoi(str));
+ struct servent *se;
+ int i = atoi(str);
+
+ if (i>0 && i<65536) return SWAP_BE16(i);
+
+ se = getservbyname(str, "tcp");
+ i = se ? se->s_port : 0;
+ endservent();
+
+ return i;
}
void netcat_main(void)
@@ -106,8 +117,8 @@ void netcat_main(void)
else {
// Setup socket
sockfd = xsocket(AF_INET, SOCK_STREAM, 0);
- fcntl(sockfd, F_SETFD, FD_CLOEXEC);
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);
@@ -119,10 +130,10 @@ void netcat_main(void)
// Dial out
- if (!CFG_NETCAT_LISTEN || !(toys.optflags&(FLAG_L|FLAG_l))) {
+ if (!(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));
+ address->sin_port = lookup_port(toys.optargs[1]);
// TODO xconnect
if (connect(sockfd, (struct sockaddr *)address, sizeof(*address))<0)
perror_exit("connect");
@@ -149,17 +160,9 @@ void netcat_main(void)
do {
child = 0;
- len = sizeof(*address); // gcc's insane optimizer can overwrite this
in1 = out2 = accept(sockfd, (struct sockaddr *)address, &len);
-
if (in1<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
-
// We have a connection. Disarm timeout.
set_alarm(0);
@@ -173,22 +176,16 @@ void netcat_main(void)
// Do we need to fork and/or redirect for exec?
- if (toys.optflags&FLAG_L) {
- toys.stacktop = 0;
- child = vfork();
- }
- 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 (toys.optflags&FLAG_L) NOEXIT(child = XVFORK());
+ 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);
}
pollinate(in1, in2, out1, out2, TT.idle, TT.quit_delay);