On 08/17/2010 11:02 AM, Daniel P. Berrange wrote:
> This re-writes the 'virsh console' command so that it uses
> the new streams API. This lets it run remotely and/or as a
> non-root user. This requires that virsh be linked against
> the simple event loop from libvirtd in daemon/event.c
> As an added bonus, it can now connect to any console device,
> not just the first one.
>
> * tools/Makefile.am: Link to event.c
> * tools/console.c, tools/console.h: Rewrite to use the
> virDomainOpenConsole() APIs with streams
> * tools/virsh.c: Support choosing the console name
> via --devname $NAME
> ---
> tools/Makefile.am | 1 +
> tools/console.c | 330 ++++++++++++++++++++++++++++++++++++++++-------------
> tools/console.h | 2 +-
> tools/virsh.c | 76 ++++---------
> 4 files changed, 274 insertions(+), 135 deletions(-)
> +
> +struct virConsoleBuffer {
> + size_t length;
> + size_t offset;
s/size_t/off_t/ for offset? (but see below)
> + char *data;
> +};
> +
> +typedef struct virConsole virConsole;
> +typedef virConsole *virConsolePtr;
> +struct virConsole {
> + virStreamPtr st;
> + int quit;
s/int/bool/, and adjust clients to use false/true instead of 0/1
> +
> + int stdinWatch;
> + int stdoutWatch;
> +
> + struct virConsoleBuffer streamToTerminal;
> + struct virConsoleBuffer terminalToStream;
> +};
> +
> static int got_signal = 0;
> static void do_signal(int sig ATTRIBUTE_UNUSED) {
> got_signal = 1;
> @@ -61,22 +86,192 @@ cfmakeraw (struct termios *attr)
> }
> # endif /* !HAVE_CFMAKERAW */
>
> -int vshRunConsole(const char *tty) {
> - int ttyfd, ret = -1;
> +static void
> +virConsoleEventOnStream(virStreamPtr st,
> + int events, void *opaque)
> +{
> + virConsolePtr con = opaque;
> +
> + if (events & VIR_STREAM_EVENT_READABLE) {
> + size_t avail = con->streamToTerminal.length -
> + con->streamToTerminal.offset;
Oh, never mind. size_t for offset is probably just fine after all.
> + int got;
> +
> + if (avail < 1024) {
> + if (VIR_REALLOC_N(con->streamToTerminal.data,
> + con->streamToTerminal.length + 1024) < 0) {
/me Note to self - another VIR_EXPAND_N or VIR_RESIZE_N candidate.
> + virReportOOMError();
> + con->quit = 1;
> + return;
> + }
> + con->streamToTerminal.length += 1024;
> + avail += 1024;
> + }
> +
> + got = virStreamRecv(st,
> + con->streamToTerminal.data +
> + con->streamToTerminal.offset,
> + avail);
> + if (got == -2)
> + return; /* blocking */
> + if (got <= 0) {
> + con->quit = 1;
> + return;
> + }
> + con->streamToTerminal.offset += got;
> + if (con->streamToTerminal.offset)
> + virEventUpdateHandleImpl(con->stdoutWatch,
> + VIR_EVENT_HANDLE_WRITABLE);
> + }
> +
> + if (events & VIR_STREAM_EVENT_WRITABLE &&
> + con->terminalToStream.offset) {
> + ssize_t done;
> + size_t avail;
> + done = virStreamSend(con->st,
> + con->terminalToStream.data,
> + con->terminalToStream.offset);
> + if (done == -2)
> + return; /* blocking */
> + if (done < 0) {
> + virErrorPtr err = virGetLastError();
> + con->quit = 1;
> + return;
> + }
> + memmove(con->terminalToStream.data,
> + con->terminalToStream.data + done,
> + con->terminalToStream.offset - done);
> + con->terminalToStream.offset -= done;
> +
> + avail = con->terminalToStream.length - con->terminalToStream.offset;
> + if (avail > 1024) {
> + if (VIR_REALLOC_N(con->terminalToStream.data,
> + con->terminalToStream.offset + 1024) < 0)
> + {}
/me Note to self - a VIR_SHRINK_N candidate.
> + con->terminalToStream.length = con->terminalToStream.offset + 1024;
> + }
> + }
> + if (!con->terminalToStream.offset)
> + virStreamEventUpdateCallback(con->st,
> + VIR_STREAM_EVENT_READABLE);
> +
> + if (events & VIR_STREAM_EVENT_ERROR ||
> + events & VIR_STREAM_EVENT_HANGUP) {
> + con->quit = 1;
> + }
> +}
> +
> +static void
> +virConsoleEventOnStdin(int watch ATTRIBUTE_UNUSED,
> + int fd ATTRIBUTE_UNUSED,
> + int events,
> + void *opaque)
> +{
> + virConsolePtr con = opaque;
> +
> + if (events & VIR_EVENT_HANDLE_READABLE) {
> + size_t avail = con->terminalToStream.length -
> + con->terminalToStream.offset;
> + int got;
> +
> + if (avail < 1024) {
> + if (VIR_REALLOC_N(con->terminalToStream.data,
> + con->terminalToStream.length + 1024) < 0) {
> + virReportOOMError();
> + con->quit = 1;
> + return;
> + }
> + con->terminalToStream.length += 1024;
> + avail += 1024;
> + }
> +
> + got = read(fd,
> + con->terminalToStream.data +
> + con->terminalToStream.offset,
> + avail);
> + if (got < 0) {
> + if (errno != EAGAIN) {
> + con->quit = 1;
> + }
> + return;
> + }
> + if (got == 0) {
> + con->quit = 1;
> + return;
> + }
> + if (con->terminalToStream.data[con->terminalToStream.offset] == CTRL_CLOSE_BRACKET) {
> + con->quit = 1;
> + return;
> + }
> +
> + con->terminalToStream.offset += got;
> + if (con->terminalToStream.offset)
> + virStreamEventUpdateCallback(con->st,
> + VIR_STREAM_EVENT_READABLE |
> + VIR_STREAM_EVENT_WRITABLE);
> + }
> +
> + if (events & VIR_EVENT_HANDLE_ERROR ||
> + events & VIR_EVENT_HANDLE_HANGUP) {
> + con->quit = 1;
> + }
> +}
> +
> +static void
> +virConsoleEventOnStdout(int watch ATTRIBUTE_UNUSED,
> + int fd,
> + int events,
> + void *opaque)
> +{
> + virConsolePtr con = opaque;
> +
> + if (events & VIR_EVENT_HANDLE_WRITABLE &&
> + con->streamToTerminal.offset) {
> + ssize_t done;
> + size_t avail;
> + done = write(fd,
> + con->streamToTerminal.data,
> + con->streamToTerminal.offset);
Do we want to use safewrite here?
Conditional ACK, if those are deemed easy nits to fix.
--
Eric Blake eblake@xxxxxxxxxx +1-801-349-2682
Libvirt virtualization library http://libvirt.org
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