* Daniel P. Berrange (berra...@redhat.com) wrote:
> On Tue, Feb 02, 2016 at 06:19:03PM +0000, Dr. David Alan Gilbert wrote:
> > * Daniel P. Berrange (berra...@redhat.com) wrote:
> > > Convert the tcp socket migration protocol driver to use
> > > QIOChannel and QEMUFileChannel, instead of plain sockets
> > > APIs.
> > >
> > > While this now looks pretty similar to the migration/unix.c
> > > file from the previous patch, it was decided not to merge
> > > the two, because when TLS is added to the TCP impl later,
> > > this file diverge from unix.c once again.
> >
> > Hmm OK, although I'd kind of like to see merging, but lets
> > see the TLS code later in the series....
> >
> > > Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
> > > ---
> > > migration/tcp.c | 119
> > > ++++++++++++++++++++++++++++++++++++++------------------
> > > 1 file changed, 82 insertions(+), 37 deletions(-)
> > >
> > > diff --git a/migration/tcp.c b/migration/tcp.c
> > > index ae89172..ac73977 100644
> > > --- a/migration/tcp.c
> > > +++ b/migration/tcp.c
> > > @@ -2,9 +2,11 @@
> > > * QEMU live migration
> > > *
> > > * Copyright IBM, Corp. 2008
> > > + * Copyright Red Hat, Inc. 2015
> > > *
> > > * Authors:
> > > * Anthony Liguori <aligu...@us.ibm.com>
> > > + * Daniel P. Berrange <berra...@redhat.com>
> > > *
> > > * This work is licensed under the terms of the GNU GPL, version 2. See
> > > * the COPYING file in the top-level directory.
> > > @@ -17,11 +19,9 @@
> > >
> > > #include "qemu-common.h"
> > > #include "qemu/error-report.h"
> > > -#include "qemu/sockets.h"
> > > #include "migration/migration.h"
> > > #include "migration/qemu-file.h"
> > > -#include "block/block.h"
> > > -#include "qemu/main-loop.h"
> > > +#include "io/channel-socket.h"
> > >
> > > //#define DEBUG_MIGRATION_TCP
> > >
> > > @@ -33,71 +33,116 @@
> > > do { } while (0)
> > > #endif
> > >
> > > -static void tcp_wait_for_connect(int fd, Error *err, void *opaque)
> > > +
> > > +static SocketAddress *tcp_build_address(const char *host_port, Error
> > > **errp)
> > > +{
> > > + InetSocketAddress *iaddr = inet_parse(host_port, errp);
> > > + SocketAddress *saddr;
> > > +
> > > + if (!iaddr) {
> > > + return NULL;
> > > + }
> > > +
> > > + saddr = g_new0(SocketAddress, 1);
> > > + saddr->type = SOCKET_ADDRESS_KIND_INET;
> > > + saddr->u.inet = iaddr;
> > > +
> > > + return saddr;
> > > +}
> > > +
> > > +
> > > +static void tcp_outgoing_migration(Object *src,
> > > + Error *err,
> > > + gpointer opaque)
> > > {
> > > MigrationState *s = opaque;
> > > + QIOChannel *sioc = QIO_CHANNEL(src);
> > >
> > > - if (fd < 0) {
> > > + if (err) {
> > > DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
> > > s->file = NULL;
> > > migrate_fd_error(s);
> > > } else {
> > > DPRINTF("migrate connect success\n");
> > > - s->file = qemu_fopen_socket(fd, "wb");
> > > + s->file = qemu_fopen_channel_output(sioc);
> > > migrate_fd_connect(s);
> > > }
> > > + object_unref(src);
> > > }
> > >
> > > -void tcp_start_outgoing_migration(MigrationState *s, const char
> > > *host_port, Error **errp)
> > > +
> > > +void tcp_start_outgoing_migration(MigrationState *s,
> > > + const char *host_port,
> > > + Error **errp)
> > > {
> > > - inet_nonblocking_connect(host_port, tcp_wait_for_connect, s, errp);
> > > + SocketAddress *saddr = tcp_build_address(host_port, errp);
> > > + QIOChannelSocket *sioc;
> > > +
> > > + if (!saddr) {
> > > + return;
> > > + }
> > > +
> > > + sioc = qio_channel_socket_new();
> > > + qio_channel_socket_connect_async(sioc,
> > > + saddr,
> > > + tcp_outgoing_migration,
> > > + s,
> > > + NULL);
> > > + qapi_free_SocketAddress(saddr);
> > > }
> > >
> > > -static void tcp_accept_incoming_migration(void *opaque)
> > > +
> > > +static gboolean tcp_accept_incoming_migration(QIOChannel *ioc,
> > > + GIOCondition condition,
> > > + gpointer opaque)
> > > {
> > > - struct sockaddr_in addr;
> > > - socklen_t addrlen = sizeof(addr);
> > > - int s = (intptr_t)opaque;
> > > QEMUFile *f;
> > > - int c, err;
> > > + QIOChannelSocket *cioc;
> > > + Error *err = NULL;
> > >
> > > - do {
> > > - c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
> > > - err = socket_error();
> > > - } while (c < 0 && err == EINTR);
> > > - qemu_set_fd_handler(s, NULL, NULL, NULL);
> > > - closesocket(s);
> > > -
> > > - DPRINTF("accepted migration\n");
> > > -
> > > - if (c < 0) {
> > > + cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
> > > + &err);
> > > + if (!cioc) {
> > > error_report("could not accept migration connection (%s)",
> > > - strerror(err));
> > > - return;
> > > - }
> > > -
> > > - f = qemu_fopen_socket(c, "rb");
> > > - if (f == NULL) {
> > > - error_report("could not qemu_fopen socket");
> > > + error_get_pretty(err));
> > > goto out;
> > > }
> > >
> > > + DPRINTF("accepted migration\n");
> > > +
> > > + f = qemu_fopen_channel_input(QIO_CHANNEL(cioc));
> > > + object_unref(OBJECT(cioc));
> > > +
> > > process_incoming_migration(f);
> > > - return;
> > >
> > > out:
> > > - closesocket(c);
> > > + /* Close listening socket as its no longer needed */
> > > + qio_channel_close(ioc, NULL);
> > > + return FALSE;
> > > }
> > >
> > > +
> > > void tcp_start_incoming_migration(const char *host_port, Error **errp)
> > > {
> > > - int s;
> > > + SocketAddress *saddr = tcp_build_address(host_port, errp);
> > > + QIOChannelSocket *listen_ioc;
> > >
> > > - s = inet_listen(host_port, NULL, 256, SOCK_STREAM, 0, errp);
> > > - if (s < 0) {
> > > + if (!saddr) {
> > > return;
> > > }
> > >
> > > - qemu_set_fd_handler(s, tcp_accept_incoming_migration, NULL,
> > > - (void *)(intptr_t)s);
> > > + listen_ioc = qio_channel_socket_new();
> > > + if (qio_channel_socket_listen_sync(listen_ioc, saddr, errp) < 0) {
> >
> > In this case, although weird, that could block couldn't it?
> > The case I'm thinking of is using the migrate_incoming command with a
> > hostname
> > (I've used it with hostnames before as aliases for networks to listen on,
> > admittedly it be rare for it to be DNS that would block).
>
> Yes it certainly could block and this is undesirable in general. The problem
> is that the only way we can provide errors back for the monitor reponse is
> if we do this synchronously from this method. If I ran async then we'd have
> no ability to report errors about non-existant host names, already in use tcp
> port, etc.
>
> I'm not really sure what todo about this long term, but the only way would
> be if the monitor response was able to be sent back asychronously from
> this method call. Then we can start an async listen call, and respond to
> the monitor when done.
>
> Since the current code being replaced is also blocking, I felt solving
> that problem is best left to a future patch series. At least with this
> explicit method naming with _sync() suffix we can easily identify the
> problems in future
Yeh that's fair enough. Failed incoming migrations generally just quit anyway.
Dave
>
> Regards,
> Daniel
> --
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--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
