On Fri, 8 Jun 2012 11:42:57 -0400 Corey Bryant <coreyb(a)linux.vnet.ibm.com&gt; wrote: > This patch adds the passfd QMP command using the QAPI framework. > Like the getfd command, it is used to pass a file descriptor via > SCM_RIGHTS. However, the passfd command also returns the received > file descriptor, which is a difference in behavior from the getfd > command, which returns nothing. Let's call it pass-fd instead.

Also, getfd automatically closes a fd if an existing fdname is passed again. I don't think this is a good behavior, I think pass-fd should fail instead (note that we can't fix getfd though).

> > The closefd command can be used to close a file descriptor that was > passed with the passfd command. > > v2: > -Introduce new QMP command to pass/return fd (lcapitulino(a)redhat.com) > -Use passfd as command name (berrange(a)redhat.com) > > Signed-off-by: Corey Bryant <coreyb(a)linux.vnet.ibm.com&gt; > --- > monitor.c | 14 ++++++++++---- > qapi-schema.json | 15 +++++++++++++++ > qmp-commands.hx | 27 +++++++++++++++++++++++++++ > 3 files changed, 52 insertions(+), 4 deletions(-) > > diff --git a/monitor.c b/monitor.c > index 4c53cb6..980a226 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -2182,7 +2182,7 @@ static void do_inject_mce(Monitor *mon, const QDict *qdict) > } > #endif > > -void qmp_getfd(const char *fdname, Error **errp) > +int64_t qmp_passfd(const char *fdname, Error **errp) > { > mon_fd_t *monfd; > int fd; > @@ -2190,13 +2190,13 @@ void qmp_getfd(const char *fdname, Error **errp) > fd = qemu_chr_fe_get_msgfd(cur_mon->chr); > if (fd == -1) { > error_set(errp, QERR_FD_NOT_SUPPLIED); > - return; > + return -1; > } > > if (qemu_isdigit(fdname[0])) { > error_set(errp, QERR_INVALID_PARAMETER_VALUE, "fdname", > "a name not starting with a digit"); > - return; > + return -1; > } > > QLIST_FOREACH(monfd, &cur_mon->fds, next) { > @@ -2206,7 +2206,7 @@ void qmp_getfd(const char *fdname, Error **errp) > > close(monfd->fd); > monfd->fd = fd; > - return; > + return fd; > } > > monfd = g_malloc0(sizeof(mon_fd_t)); > @@ -2214,6 +2214,12 @@ void qmp_getfd(const char *fdname, Error **errp) > monfd->fd = fd; > > QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next); > + return fd; > +} > + > +void qmp_getfd(const char *fdname, Error **errp) > +{ > + qmp_passfd(fdname, errp); > return; > } > > diff --git a/qapi-schema.json b/qapi-schema.json > index 6be1d90..15da1b8 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -1864,6 +1864,21 @@ > { 'command': 'netdev_del', 'data': {'id': 'str'} } > > ## > +# @passfd: > +# > +# Pass a file descriptor via SCM rights and assign it a name > +# > +# @fdname: file descriptor name > +# > +# Returns: The QEMU file descriptor that was received > +# If file descriptor was not received, FdNotSupplied > +# If @fdname is not valid, InvalidParameterType > +# > +# Since: 1.2.0 > +## > +{ 'command': 'passfd', 'data': {'fdname': 'str'}, 'returns': 'int' } > + > +## > # @getfd: > # > # Receive a file descriptor via SCM rights and assign it a name > diff --git a/qmp-commands.hx b/qmp-commands.hx > index f8c0f68..338a0b3 100644 > --- a/qmp-commands.hx > +++ b/qmp-commands.hx > @@ -869,6 +869,33 @@ Example: > EQMP > > { > + .name = "passfd", > + .args_type = "fdname:s", > + .params = "passfd name", > + .help = "pass a file descriptor via SCM rights and assign it a name", > + .mhandler.cmd_new = qmp_marshal_input_passfd, > + }, > + > +SQMP > +passfd > +------ > + > +Pass a file descriptor via SCM rights and assign it a name. > + > +Arguments: > + > +- "fdname": file descriptor name (json-string) > + > +Return a json-int with the QEMU file descriptor that was received. > + > +Example: > + > +-> { "execute": "passfd", "arguments": { "fdname": "fd1" } } > +<- { "return": 42 } > + > +EQMP > + > + { > .name = "getfd", > .args_type = "fdname:s", > .params = "getfd name",