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| | From: Aron Xu <aron@debian.org>
Date: Mon, 13 Feb 2012 14:43:56 +0800
Subject: connect timeout
---
netcat.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 75 insertions(+), 2 deletions(-)
diff --git a/netcat.c b/netcat.c
index 9b2def2..f3cc8c1 100644
--- a/netcat.c
+++ b/netcat.c
@@ -106,6 +106,10 @@
#define PORT_MAX_LEN 6
#define UNIX_DG_TMP_SOCKET_SIZE 19
+#define CONNECTION_SUCCESS 0
+#define CONNECTION_FAILED 1
+#define CONNECTION_TIMEOUT 2
+
/* Command Line Options */
int dflag; /* detached, no stdin */
unsigned int iflag; /* Interval Flag */
@@ -151,6 +155,9 @@ void set_common_sockopts(int);
int map_tos(char *, int *);
void usage(int);
+static int connect_with_timeout(int fd, const struct sockaddr *sa,
+ socklen_t salen, int ctimeout);
+
int
main(int argc, char *argv[])
{
@@ -651,11 +658,14 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)
set_common_sockopts(s);
- if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0)
+ if ((error = connect_with_timeout(s, res0->ai_addr, res0->ai_addrlen, timeout))== CONNECTION_SUCCESS)
break;
- else if (vflag)
+ else if (vflag && error == CONNECTION_FAILED)
warn("connect to %s port %s (%s) failed", host, port,
uflag ? "udp" : "tcp");
+ else if (vflag && error == CONNECTION_TIMEOUT)
+ warn("connect to %s port %s (%s) timed out", host, port,
+ uflag ? "udp" : "tcp");
close(s);
s = -1;
@@ -703,6 +713,69 @@ timeout_connect(int s, const struct sockaddr *name, socklen_t namelen)
return (ret);
}
+static int connect_with_timeout(int fd, const struct sockaddr *sa,
+ socklen_t salen, int ctimeout)
+{
+ int err;
+ struct timeval tv, *tvp = NULL;
+ fd_set connect_fdset;
+ socklen_t len;
+ int orig_flags;
+
+ orig_flags = fcntl(fd, F_GETFL, 0);
+ if (fcntl(fd, F_SETFL, orig_flags | O_NONBLOCK) < 0 ) {
+ warn("can't set O_NONBLOCK - timeout not available");
+ if (connect(fd, sa, salen) == 0)
+ return CONNECTION_SUCCESS;
+ else
+ return CONNECTION_FAILED;
+ }
+
+ /* set connect timeout */
+ if (ctimeout > 0) {
+ tv.tv_sec = (time_t)ctimeout/1000;
+ tv.tv_usec = 0;
+ tvp = &tv;
+ }
+
+ /* attempt the connection */
+ err = connect(fd, sa, salen);
+ if (err != 0 && errno == EINPROGRESS) {
+ /* connection is proceeding
+ * it is complete (or failed) when select returns */
+
+ /* initialize connect_fdset */
+ FD_ZERO(&connect_fdset);
+ FD_SET(fd, &connect_fdset);
+
+ /* call select */
+ do {
+ err = select(fd + 1, NULL, &connect_fdset,
+ NULL, tvp);
+ } while (err < 0 && errno == EINTR);
+
+ /* select error */
+ if (err < 0)
+ errx(1,"select error: %s", strerror(errno));
+ /* we have reached a timeout */
+ if (err == 0)
+ return CONNECTION_TIMEOUT;
+ /* select returned successfully, but we must test socket
+ * error for result */
+ len = sizeof(err);
+ if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len) < 0)
+ errx(1, "getsockopt error: %s", strerror(errno));
+ /* setup errno according to the result returned by
+ * getsockopt */
+ if (err != 0)
+ errno = err;
+ }
+
+ /* return aborted if an error occured, and valid otherwise */
+ fcntl(fd, F_SETFL, orig_flags);
+ return (err != 0)? CONNECTION_FAILED : CONNECTION_SUCCESS;
+}
+
/*
* local_listen()
* Returns a socket listening on a local port, binds to specified source
--
|