Add set_sock_nonblock() and set_fd_cloexec() compat functions

The latter does nothing on Windows, and the former is *only* for sockets.

Which means that it's probably broken where we're using it on pipes, but
we'll deal with that later...

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

dtls.c

@@ -547,8 +547,8 @@ int connect_dtls_socket(struct openconnect_info *vpninfo)
 		return -EINVAL;
 	}
 
-	fcntl(dtls_fd, F_SETFD, FD_CLOEXEC);
-	fcntl(dtls_fd, F_SETFL, fcntl(dtls_fd, F_GETFL) | O_NONBLOCK);
+	set_fd_cloexec(dtls_fd);
+	set_sock_nonblock(dtls_fd);
 
 	ret = start_dtls_handshake(vpninfo, dtls_fd);
 	if (ret) {

library.c

@@ -379,8 +379,7 @@ int openconnect_setup_cmd_pipe(struct openconnect_info *vpninfo)
 
 	if (pipe(pipefd) < 0)
 		return -EIO;
-	if (fcntl(pipefd[0], F_SETFL, O_NONBLOCK) ||
-	    fcntl(pipefd[1], F_SETFL, O_NONBLOCK)) {
+	if (set_sock_nonblock(pipefd[0]) || set_sock_nonblock(pipefd[1])) {
 		close(pipefd[0]);
 		close(pipefd[1]);
 		return -EIO;

openconnect-internal.h

@@ -67,6 +67,7 @@
 #include <netdb.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <fcntl.h>
 #endif
 
 #ifdef LIBPROXY_HDR
@@ -369,6 +370,24 @@ void openconnect__unsetenv(const char *name);
 int openconnect__inet_aton(const char *cp, struct in_addr *addr);
 #endif
 
+static inline int set_sock_nonblock(int fd)
+{
+#ifdef _WIN32
+	unsigned long mode = 0;
+	return ioctlsocket(fd, FIONBIO, &mode);
+#else
+	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
+#endif
+}
+static inline int set_fd_cloexec(int fd)
+{
+#ifdef _WIN32
+	return 0; /* Windows has O_INHERIT but... */
+#else
+	return fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+}
+
 #ifdef _WIN32
 #define pipe(fds) _pipe(fds, 4096, O_BINARY)
 #define neterrno openconnect__win32_neterrno

ssl.c

@@ -62,7 +62,7 @@ static int cancellable_connect(struct openconnect_info *vpninfo, int sockfd,
 	fd_set wr_set, rd_set;
 	int maxfd = sockfd;
 
-	fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFL) | O_NONBLOCK);
+	set_sock_nonblock(sockfd);
 	if (vpninfo->protect_socket)
 		vpninfo->protect_socket(vpninfo->cbdata, sockfd);
 
@@ -105,7 +105,7 @@ int connect_https_socket(struct openconnect_info *vpninfo)
 			ssl_sock = socket(vpninfo->peer_addr->sa_family, SOCK_STREAM, IPPROTO_IP);
 			if (ssl_sock < 0)
 				goto reconn_err;
-			fcntl(ssl_sock, F_SETFD, fcntl(ssl_sock, F_GETFD) | FD_CLOEXEC);
+			set_fd_cloexec(ssl_sock);
 		}
 		if (cancellable_connect(vpninfo, ssl_sock, vpninfo->peer_addr, vpninfo->peer_addrlen)) {
 		reconn_err:
@@ -234,7 +234,7 @@ int connect_https_socket(struct openconnect_info *vpninfo)
 					  rp->ai_protocol);
 			if (ssl_sock < 0)
 				continue;
-			fcntl(ssl_sock, F_SETFD, fcntl(ssl_sock, F_GETFD) | FD_CLOEXEC);
+			set_fd_cloexec(ssl_sock);
 			if (cancellable_connect(vpninfo, ssl_sock, rp->ai_addr, rp->ai_addrlen) >= 0) {
 				/* Store the peer address we actually used, so that DTLS can
 				   use it again later */

tun.c

@@ -633,7 +633,7 @@ static int os_setup_tun(struct openconnect_info *vpninfo)
 
 int openconnect_setup_tun_fd(struct openconnect_info *vpninfo, int tun_fd)
 {
-	fcntl(tun_fd, F_SETFD, FD_CLOEXEC);
+	set_fd_cloexec(tun_fd);
 
 	if (vpninfo->tun_fd != -1)
 		FD_CLR(vpninfo->tun_fd, &vpninfo->select_rfds);
@@ -644,7 +644,7 @@ int openconnect_setup_tun_fd(struct openconnect_info *vpninfo, int tun_fd)
 
 	FD_SET(tun_fd, &vpninfo->select_rfds);
 
-	fcntl(vpninfo->tun_fd, F_SETFL, fcntl(vpninfo->tun_fd, F_GETFL) | O_NONBLOCK);
+	set_sock_nonblock(tun_fd);
 
 	return 0;
 }