Re: [libvirt] [PATCH 6/7] Re-write virsh console to use streams

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;

+ char *data; +}; + +typedef struct virConsole virConsole; +typedef virConsole *virConsolePtr; +struct virConsole { + virStreamPtr st; + int quit;

+ + 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;

+ int got; + + if (avail < 1024) { + if (VIR_REALLOC_N(con->streamToTerminal.data, + con->streamToTerminal.length + 1024) < 0) {

+ 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) + {}

+ 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);