From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51272) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9B0E-00026M-PD for qemu-devel@nongnu.org; Thu, 08 Jan 2015 06:11:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y9B09-0008Fd-QY for qemu-devel@nongnu.org; Thu, 08 Jan 2015 06:11:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49023) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9B09-0008FU-Hj for qemu-devel@nongnu.org; Thu, 08 Jan 2015 06:11:41 -0500 From: "Dr. David Alan Gilbert (git)" Date: Thu, 8 Jan 2015 11:11:31 +0000 Message-Id: <1420715492-5109-3-git-send-email-dgilbert@redhat.com> In-Reply-To: <1420715492-5109-1-git-send-email-dgilbert@redhat.com> References: <1420715492-5109-1-git-send-email-dgilbert@redhat.com> Subject: [Qemu-devel] [PATCH 2/3] Handle bi-directional communication for fd migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: amit.shah@redhat.com, cristian.klein@cs.umu.se, quintela@redhat.com From: Cristian Klein libvirt prefers opening the TCP connection itself, for two reasons. First, connection failed errors can be detected easier, without having to parse qemu's error output. Second, libvirt might be asked to secure the transfer by tunnelling the communication through an TLS layer. Therefore, libvirt opens the TCP connection itself and passes an FD to qemu using QMP and a POSIX-specific mechanism. Hence, in order to make the reverse-path work in such cases, qemu needs to distinguish if the transmitted FD is a socket (reverse-path available) or not (reverse-path might not be available) and use the corresponding abstraction. Signed-off-by: Cristian Klein --- migration/fd.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/migration/fd.c b/migration/fd.c index d2e523a..129da99 100644 --- a/migration/fd.c +++ b/migration/fd.c @@ -31,13 +31,29 @@ do { } while (0) #endif +static bool fd_is_socket(int fd) +{ + struct stat stat; + int ret = fstat(fd, &stat); + if (ret == -1) { + /* When in doubt say no */ + return false; + } + return S_ISSOCK(stat.st_mode); +} + void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp) { int fd = monitor_get_fd(cur_mon, fdname, errp); if (fd == -1) { return; } - s->file = qemu_fdopen(fd, "wb"); + + if (fd_is_socket(fd)) { + s->file = qemu_fopen_socket(fd, "wb"); + } else { + s->file = qemu_fdopen(fd, "wb"); + } migrate_fd_connect(s); } @@ -58,7 +74,11 @@ void fd_start_incoming_migration(const char *infd, Error **errp) DPRINTF("Attempting to start an incoming migration via fd\n"); fd = strtol(infd, NULL, 0); - f = qemu_fdopen(fd, "rb"); + if (fd_is_socket(fd)) { + f = qemu_fopen_socket(fd, "rb"); + } else { + f = qemu_fdopen(fd, "rb"); + } if(f == NULL) { error_setg_errno(errp, errno, "failed to open the source descriptor"); return; -- 2.1.0