Re: [libvirt] [PATCH] command: enforce fd vs. buffer considerations

* docs/internals/command.html.in: Better documentation of buffer vs. fd considerations. * src/util/command.c (virCommandRunAsync): Reject raw execution with string io. (virCommandRun): Reject execution with user-specified fds not visiting a regular file. --- Perhaps we need to relax the fstat check to permit block devices in addition to regular files; but that can be a later patch if needed.  docs/internals/command.html.in |   35 ++++++++++++++++++++++++++---------  src/util/command.c             |   37 ++++++++++++++++++++++++++++++++++++-  2 files changed, 62 insertions(+), 10 deletions(-)

+    if (async_io ? (!(cmd->flags & VIR_EXEC_DAEMON) || string_io) +        : ((cmd->flags & VIR_EXEC_DAEMON) && string_io)) { +        virCommandError(VIR_ERR_INTERNAL_ERROR, "%s", +                        _("invalid use of command API")); +        return -1; +    }

+    /* Buffer management can only be requested via virCommandRun.  */ +    if ((cmd->inbuf && cmd->infd == -1) || +        (cmd->outbuf && cmd->outfdptr != &cmd->outfd) || +        (cmd->errbuf && cmd->errfdptr != &cmd->errfd)) { +        virCommandError(VIR_ERR_INTERNAL_ERROR, "%s", +                        _("invalid use of command API")); +        return -1; +    }