Add cancellation handling to proxy I/O functions

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

http.c

@@ -899,9 +899,31 @@ static int proxy_write(struct openconnect_info *vpninfo, int fd,
 		       unsigned char *buf, size_t len)
 {
 	size_t count;
-	
+
 	for (count = 0; count < len; ) {
-		int i = write(fd, buf + count, len - count);
+		fd_set rd_set, wr_set;
+		int maxfd = fd;
+		int i;
+
+		FD_ZERO(&wr_set);
+		FD_ZERO(&rd_set);
+		FD_SET(fd, &wr_set);
+		if (vpninfo->cancel_fd != -1) {
+			FD_SET(vpninfo->cancel_fd, &rd_set);
+			if (vpninfo->cancel_fd > fd)
+				maxfd = vpninfo->cancel_fd;
+		}
+
+		select(maxfd + 1, &rd_set, &wr_set, NULL, NULL);
+		if (vpninfo->cancel_fd != -1 &&
+		    FD_ISSET(vpninfo->cancel_fd, &rd_set))
+			return -EINTR;
+
+		/* Not that this should ever be able to happen... */
+		if (!FD_ISSET(fd, &wr_set))
+			continue;
+
+		i = write(fd, buf + count, len - count);
 		if (i < 0)
 			return -errno;
 
@@ -916,7 +938,28 @@ static int proxy_read(struct openconnect_info *vpninfo, int fd,
 	size_t count;
 
 	for (count = 0; count < len; ) {
-		int i = read(fd, buf + count, len - count);
+		fd_set rd_set;
+		int maxfd = fd;
+		int i;
+
+		FD_ZERO(&rd_set);
+		FD_SET(fd, &rd_set);
+		if (vpninfo->cancel_fd != -1) {
+			FD_SET(vpninfo->cancel_fd, &rd_set);
+			if (vpninfo->cancel_fd > fd)
+				maxfd = vpninfo->cancel_fd;
+		}
+
+		select(maxfd + 1, &rd_set, NULL, NULL, NULL);
+		if (vpninfo->cancel_fd != -1 &&
+		    FD_ISSET(vpninfo->cancel_fd, &rd_set))
+			return -EINTR;
+
+		/* Not that this should ever be able to happen... */
+		if (!FD_ISSET(fd, &rd_set))
+			continue;
+
+		i = read(fd, buf + count, len - count);
 		if (i < 0)
 			return -errno;
 

ssl.c

@@ -1062,8 +1062,6 @@ int openconnect_open_https(struct openconnect_info *vpninfo)
 		}
 	}
 	fcntl(ssl_sock, F_SETFD, FD_CLOEXEC);
-	/* Stick it back in blocking mode for now... */
-	fcntl(ssl_sock, F_SETFL, fcntl(ssl_sock, F_GETFL) & ~O_NONBLOCK);
 
 	if (vpninfo->proxy) {
 		err = process_proxy(vpninfo, ssl_sock);
@@ -1073,6 +1071,9 @@ int openconnect_open_https(struct openconnect_info *vpninfo)
 		}
 	}
 
+	/* Stick it back in blocking mode for now... */
+	fcntl(ssl_sock, F_SETFL, fcntl(ssl_sock, F_GETFL) & ~O_NONBLOCK);
+
 	ssl3_method = TLSv1_client_method();
 	if (!vpninfo->https_ctx) {
 		vpninfo->https_ctx = SSL_CTX_new(ssl3_method);