Message ID | 20171005152856.6166-1-berrange@redhat.com |
---|---|
State | New |
Headers | show |
Series | char: don't skip client cleanup if 'connected' flag is unset | expand |
On 10/05/2017 10:28 AM, Daniel P. Berrange wrote: > The tcp_chr_free_connection & tcp_chr_disconnect methods both > skip all of their cleanup work unless the 's->connected' flag > is set. This flag is set when the incoming client connection > is ready to use. Crucially this is *after* the TLS handshake > has been completed. So if the TLS handshake fails and we try > to cleanup the failed client, all the cleanup is skipped as > 's->connected' is still false. > > The only important thing that should be skipped in this case > is sending of the CHR_EVENT_CLOSED, because we never got as > far as sending the corresponding CHR_EVENT_OPENED. Every other > bit of cleanup can be robust against being called even when > s->connected is false. > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > chardev/char-socket.c | 31 +++++++++++++++++-------------- > 1 file changed, 17 insertions(+), 14 deletions(-) > Reviewed-by: Eric Blake <eblake@redhat.com>
Hi On Thu, Oct 5, 2017 at 5:28 PM, Daniel P. Berrange <berrange@redhat.com> wrote: > The tcp_chr_free_connection & tcp_chr_disconnect methods both > skip all of their cleanup work unless the 's->connected' flag > is set. This flag is set when the incoming client connection > is ready to use. Crucially this is *after* the TLS handshake > has been completed. So if the TLS handshake fails and we try > to cleanup the failed client, all the cleanup is skipped as > 's->connected' is still false. > > The only important thing that should be skipped in this case > is sending of the CHR_EVENT_CLOSED, because we never got as > far as sending the corresponding CHR_EVENT_OPENED. Every other > bit of cleanup can be robust against being called even when > s->connected is false. > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > chardev/char-socket.c | 31 +++++++++++++++++-------------- > 1 file changed, 17 insertions(+), 14 deletions(-) > > diff --git a/chardev/char-socket.c b/chardev/char-socket.c > index e65148fe97..a34d4d72c2 100644 > --- a/chardev/char-socket.c > +++ b/chardev/char-socket.c > @@ -332,10 +332,6 @@ static void tcp_chr_free_connection(Chardev *chr) > SocketChardev *s = SOCKET_CHARDEV(chr); > int i; > > - if (!s->connected) { > - return; > - } > - > if (s->read_msgfds_num) { > for (i = 0; i < s->read_msgfds_num; i++) { > close(s->read_msgfds[i]); > @@ -347,10 +343,14 @@ static void tcp_chr_free_connection(Chardev *chr) > > tcp_set_msgfds(chr, NULL, 0); > remove_fd_in_watch(chr); > - object_unref(OBJECT(s->sioc)); > - s->sioc = NULL; > - object_unref(OBJECT(s->ioc)); > - s->ioc = NULL; > + if (s->sioc) { > + object_unref(OBJECT(s->sioc)); > + s->sioc = NULL; > + } > + if (s->ioc) { > + object_unref(OBJECT(s->ioc)); > + s->ioc = NULL; > + } object_unref() and OBJECT() are null-safe. > g_free(chr->filename); > chr->filename = NULL; > s->connected = 0; > @@ -394,22 +394,25 @@ static void update_disconnected_filename(SocketChardev *s) > s->is_listen, s->is_telnet); > } > > +/* NB may be called even if tcp_chr_connect has not been > + * reached, due to TLS or telnet initialization failure, > + * so can *not* assume s->connected == true > + */ > static void tcp_chr_disconnect(Chardev *chr) > { > SocketChardev *s = SOCKET_CHARDEV(chr); > - > - if (!s->connected) { > - return; > - } > + bool emitClose = s->connected; ewh, which code style do you pick today? :) > > tcp_chr_free_connection(chr); > > - if (s->listen_ioc) { > + if (s->listen_ioc && s->listen_tag == 0) { > s->listen_tag = qio_channel_add_watch( > QIO_CHANNEL(s->listen_ioc), G_IO_IN, tcp_chr_accept, chr, NULL); > } > update_disconnected_filename(s); > - qemu_chr_be_event(chr, CHR_EVENT_CLOSED); > + if (emitClose) { > + qemu_chr_be_event(chr, CHR_EVENT_CLOSED); > + } > if (s->reconnect_time) { > qemu_chr_socket_restart_timer(chr); > } > -- > 2.13.5 > > other than that, looks good to me
On Thu, Oct 05, 2017 at 05:35:39PM +0200, Marc-André Lureau wrote: > Hi > > On Thu, Oct 5, 2017 at 5:28 PM, Daniel P. Berrange <berrange@redhat.com> wrote: > > The tcp_chr_free_connection & tcp_chr_disconnect methods both > > skip all of their cleanup work unless the 's->connected' flag > > is set. This flag is set when the incoming client connection > > is ready to use. Crucially this is *after* the TLS handshake > > has been completed. So if the TLS handshake fails and we try > > to cleanup the failed client, all the cleanup is skipped as > > 's->connected' is still false. > > > > The only important thing that should be skipped in this case > > is sending of the CHR_EVENT_CLOSED, because we never got as > > far as sending the corresponding CHR_EVENT_OPENED. Every other > > bit of cleanup can be robust against being called even when > > s->connected is false. > > > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > > --- > > chardev/char-socket.c | 31 +++++++++++++++++-------------- > > 1 file changed, 17 insertions(+), 14 deletions(-) > > > > diff --git a/chardev/char-socket.c b/chardev/char-socket.c > > index e65148fe97..a34d4d72c2 100644 > > --- a/chardev/char-socket.c > > +++ b/chardev/char-socket.c > > @@ -332,10 +332,6 @@ static void tcp_chr_free_connection(Chardev *chr) > > SocketChardev *s = SOCKET_CHARDEV(chr); > > int i; > > > > - if (!s->connected) { > > - return; > > - } > > - > > if (s->read_msgfds_num) { > > for (i = 0; i < s->read_msgfds_num; i++) { > > close(s->read_msgfds[i]); > > @@ -347,10 +343,14 @@ static void tcp_chr_free_connection(Chardev *chr) > > > > tcp_set_msgfds(chr, NULL, 0); > > remove_fd_in_watch(chr); > > - object_unref(OBJECT(s->sioc)); > > - s->sioc = NULL; > > - object_unref(OBJECT(s->ioc)); > > - s->ioc = NULL; > > + if (s->sioc) { > > + object_unref(OBJECT(s->sioc)); > > + s->sioc = NULL; > > + } > > + if (s->ioc) { > > + object_unref(OBJECT(s->ioc)); > > + s->ioc = NULL; > > + } > > object_unref() and OBJECT() are null-safe. > > > g_free(chr->filename); > > chr->filename = NULL; > > s->connected = 0; > > @@ -394,22 +394,25 @@ static void update_disconnected_filename(SocketChardev *s) > > s->is_listen, s->is_telnet); > > } > > > > +/* NB may be called even if tcp_chr_connect has not been > > + * reached, due to TLS or telnet initialization failure, > > + * so can *not* assume s->connected == true > > + */ > > static void tcp_chr_disconnect(Chardev *chr) > > { > > SocketChardev *s = SOCKET_CHARDEV(chr); > > - > > - if (!s->connected) { > > - return; > > - } > > + bool emitClose = s->connected; > > ewh, which code style do you pick today? :) Which bit don't you like ? The 'bool' or the camelCase, or both ? Regards, Daniel
Hi On Thu, Oct 5, 2017 at 5:40 PM, Daniel P. Berrange <berrange@redhat.com> wrote: > On Thu, Oct 05, 2017 at 05:35:39PM +0200, Marc-André Lureau wrote: >> Hi >> >> On Thu, Oct 5, 2017 at 5:28 PM, Daniel P. Berrange <berrange@redhat.com> wrote: >> > The tcp_chr_free_connection & tcp_chr_disconnect methods both >> > skip all of their cleanup work unless the 's->connected' flag >> > is set. This flag is set when the incoming client connection >> > is ready to use. Crucially this is *after* the TLS handshake >> > has been completed. So if the TLS handshake fails and we try >> > to cleanup the failed client, all the cleanup is skipped as >> > 's->connected' is still false. >> > >> > The only important thing that should be skipped in this case >> > is sending of the CHR_EVENT_CLOSED, because we never got as >> > far as sending the corresponding CHR_EVENT_OPENED. Every other >> > bit of cleanup can be robust against being called even when >> > s->connected is false. >> > >> > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> >> > --- >> > chardev/char-socket.c | 31 +++++++++++++++++-------------- >> > 1 file changed, 17 insertions(+), 14 deletions(-) >> > >> > diff --git a/chardev/char-socket.c b/chardev/char-socket.c >> > index e65148fe97..a34d4d72c2 100644 >> > --- a/chardev/char-socket.c >> > +++ b/chardev/char-socket.c >> > @@ -332,10 +332,6 @@ static void tcp_chr_free_connection(Chardev *chr) >> > SocketChardev *s = SOCKET_CHARDEV(chr); >> > int i; >> > >> > - if (!s->connected) { >> > - return; >> > - } >> > - >> > if (s->read_msgfds_num) { >> > for (i = 0; i < s->read_msgfds_num; i++) { >> > close(s->read_msgfds[i]); >> > @@ -347,10 +343,14 @@ static void tcp_chr_free_connection(Chardev *chr) >> > >> > tcp_set_msgfds(chr, NULL, 0); >> > remove_fd_in_watch(chr); >> > - object_unref(OBJECT(s->sioc)); >> > - s->sioc = NULL; >> > - object_unref(OBJECT(s->ioc)); >> > - s->ioc = NULL; >> > + if (s->sioc) { >> > + object_unref(OBJECT(s->sioc)); >> > + s->sioc = NULL; >> > + } >> > + if (s->ioc) { >> > + object_unref(OBJECT(s->ioc)); >> > + s->ioc = NULL; >> > + } >> >> object_unref() and OBJECT() are null-safe. >> >> > g_free(chr->filename); >> > chr->filename = NULL; >> > s->connected = 0; >> > @@ -394,22 +394,25 @@ static void update_disconnected_filename(SocketChardev *s) >> > s->is_listen, s->is_telnet); >> > } >> > >> > +/* NB may be called even if tcp_chr_connect has not been >> > + * reached, due to TLS or telnet initialization failure, >> > + * so can *not* assume s->connected == true >> > + */ >> > static void tcp_chr_disconnect(Chardev *chr) >> > { >> > SocketChardev *s = SOCKET_CHARDEV(chr); >> > - >> > - if (!s->connected) { >> > - return; >> > - } >> > + bool emitClose = s->connected; >> >> ewh, which code style do you pick today? :) > > Which bit don't you like ? The 'bool' or the camelCase, or both ? the mixedCase, let's stick to lower_case for variables. > > > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
diff --git a/chardev/char-socket.c b/chardev/char-socket.c index e65148fe97..a34d4d72c2 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -332,10 +332,6 @@ static void tcp_chr_free_connection(Chardev *chr) SocketChardev *s = SOCKET_CHARDEV(chr); int i; - if (!s->connected) { - return; - } - if (s->read_msgfds_num) { for (i = 0; i < s->read_msgfds_num; i++) { close(s->read_msgfds[i]); @@ -347,10 +343,14 @@ static void tcp_chr_free_connection(Chardev *chr) tcp_set_msgfds(chr, NULL, 0); remove_fd_in_watch(chr); - object_unref(OBJECT(s->sioc)); - s->sioc = NULL; - object_unref(OBJECT(s->ioc)); - s->ioc = NULL; + if (s->sioc) { + object_unref(OBJECT(s->sioc)); + s->sioc = NULL; + } + if (s->ioc) { + object_unref(OBJECT(s->ioc)); + s->ioc = NULL; + } g_free(chr->filename); chr->filename = NULL; s->connected = 0; @@ -394,22 +394,25 @@ static void update_disconnected_filename(SocketChardev *s) s->is_listen, s->is_telnet); } +/* NB may be called even if tcp_chr_connect has not been + * reached, due to TLS or telnet initialization failure, + * so can *not* assume s->connected == true + */ static void tcp_chr_disconnect(Chardev *chr) { SocketChardev *s = SOCKET_CHARDEV(chr); - - if (!s->connected) { - return; - } + bool emitClose = s->connected; tcp_chr_free_connection(chr); - if (s->listen_ioc) { + if (s->listen_ioc && s->listen_tag == 0) { s->listen_tag = qio_channel_add_watch( QIO_CHANNEL(s->listen_ioc), G_IO_IN, tcp_chr_accept, chr, NULL); } update_disconnected_filename(s); - qemu_chr_be_event(chr, CHR_EVENT_CLOSED); + if (emitClose) { + qemu_chr_be_event(chr, CHR_EVENT_CLOSED); + } if (s->reconnect_time) { qemu_chr_socket_restart_timer(chr); }
The tcp_chr_free_connection & tcp_chr_disconnect methods both skip all of their cleanup work unless the 's->connected' flag is set. This flag is set when the incoming client connection is ready to use. Crucially this is *after* the TLS handshake has been completed. So if the TLS handshake fails and we try to cleanup the failed client, all the cleanup is skipped as 's->connected' is still false. The only important thing that should be skipped in this case is sending of the CHR_EVENT_CLOSED, because we never got as far as sending the corresponding CHR_EVENT_OPENED. Every other bit of cleanup can be robust against being called even when s->connected is false. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- chardev/char-socket.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-)