| Message ID | 20201125100220.50251-2-armbru@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net: Fix handling of id in netdev_add and netdev_del | expand |
On 11/25/20 4:02 AM, Markus Armbruster wrote: > CLI -netdev accumulates in option group "netdev". > > Before commit 08712fcb85 "net: Track netdevs in NetClientState rather > than QemuOpt", netdev_add added to the option group, and netdev_del > removed from it, both HMP and QMP. Thus, every netdev had a > corresponding QemuOpts in this option group. > > Commit 08712fcb85 dropped this for QMP netdev_add and both netdev_del. > Now a netdev has a corresponding QemuOpts only when it was created > with CLI or HMP. Two issues: > > * QMP and HMP netdev_del can leave QemuOpts behind, breaking HMP > netdev_add. Reproducer: > > $ qemu-system-x86_64 -S -display none -nodefaults -monitor stdio > QEMU 5.1.92 monitor - type 'help' for more information > (qemu) netdev_add user,id=net0 > (qemu) info network > net0: index=0,type=user,net=10.0.2.0,restrict=off > (qemu) netdev_del net0 > (qemu) info network > (qemu) netdev_add user,id=net0 > upstream-qemu: Duplicate ID 'net0' for netdev > Try "help netdev_add" for more information > > Fix by restoring the QemuOpts deletion in qmp_netdev_del(), but with > a guard, because the QemuOpts need not exist. > > * QMP netdev_add loses its "no duplicate ID" check. Reproducer: > > $ qemu-system-x86_64 -S -display none -qmp stdio > {"QMP": {"version": {"qemu": {"micro": 92, "minor": 1, "major": 5}, "package": "v5.2.0-rc2-1-g02c1f0142c"}, "capabilities": ["oob"]}} > {"execute": "qmp_capabilities"} > {"return": {}} > {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}} > {"return": {}} > {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}} > {"return": {}} > > Fix by adding a duplicate ID check to net_client_init1() to replace > the lost one. The check is redundant for callers where QemuOpts > still checks, i.e. for CLI and HMP. > > Reported-by: Andrew Melnichenko <andrew@daynix.com> > Fixes: 08712fcb851034228b61f75bd922863a984a4f60 > Cc: qemu-stable@nongnu.org > Signed-off-by: Markus Armbruster <armbru@redhat.com> > --- > net/net.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) The adventure in QAPIfication of netdev_add has been long. Thanks for working on this. Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/net/net.c b/net/net.c index 794c652282..c1dc75fc37 100644 --- a/net/net.c +++ b/net/net.c @@ -978,6 +978,7 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])( static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp) { NetClientState *peer = NULL; + NetClientState *nc; if (is_netdev) { if (netdev->type == NET_CLIENT_DRIVER_NIC || @@ -1005,6 +1006,12 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp) } } + nc = qemu_find_netdev(netdev->id); + if (nc) { + error_setg(errp, "Duplicate ID '%s'", netdev->id); + return -1; + } + if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) { /* FIXME drop when all init functions store an Error */ if (errp && !*errp) { @@ -1015,8 +1022,6 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp) } if (is_netdev) { - NetClientState *nc; - nc = qemu_find_netdev(netdev->id); assert(nc); nc->is_netdev = true; @@ -1137,6 +1142,7 @@ void qmp_netdev_add(Netdev *netdev, Error **errp) void qmp_netdev_del(const char *id, Error **errp) { NetClientState *nc; + QemuOpts *opts; nc = qemu_find_netdev(id); if (!nc) { @@ -1151,6 +1157,16 @@ void qmp_netdev_del(const char *id, Error **errp) } qemu_del_net_client(nc); + + /* + * Wart: we need to delete the QemuOpts associated with netdevs + * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in + * HMP netdev_add. + */ + opts = qemu_opts_find(qemu_find_opts("netdev"), id); + if (opts) { + qemu_opts_del(opts); + } } static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
CLI -netdev accumulates in option group "netdev". Before commit 08712fcb85 "net: Track netdevs in NetClientState rather than QemuOpt", netdev_add added to the option group, and netdev_del removed from it, both HMP and QMP. Thus, every netdev had a corresponding QemuOpts in this option group. Commit 08712fcb85 dropped this for QMP netdev_add and both netdev_del. Now a netdev has a corresponding QemuOpts only when it was created with CLI or HMP. Two issues: * QMP and HMP netdev_del can leave QemuOpts behind, breaking HMP netdev_add. Reproducer: $ qemu-system-x86_64 -S -display none -nodefaults -monitor stdio QEMU 5.1.92 monitor - type 'help' for more information (qemu) netdev_add user,id=net0 (qemu) info network net0: index=0,type=user,net=10.0.2.0,restrict=off (qemu) netdev_del net0 (qemu) info network (qemu) netdev_add user,id=net0 upstream-qemu: Duplicate ID 'net0' for netdev Try "help netdev_add" for more information Fix by restoring the QemuOpts deletion in qmp_netdev_del(), but with a guard, because the QemuOpts need not exist. * QMP netdev_add loses its "no duplicate ID" check. Reproducer: $ qemu-system-x86_64 -S -display none -qmp stdio {"QMP": {"version": {"qemu": {"micro": 92, "minor": 1, "major": 5}, "package": "v5.2.0-rc2-1-g02c1f0142c"}, "capabilities": ["oob"]}} {"execute": "qmp_capabilities"} {"return": {}} {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}} {"return": {}} {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}} {"return": {}} Fix by adding a duplicate ID check to net_client_init1() to replace the lost one. The check is redundant for callers where QemuOpts still checks, i.e. for CLI and HMP. Reported-by: Andrew Melnichenko <andrew@daynix.com> Fixes: 08712fcb851034228b61f75bd922863a984a4f60 Cc: qemu-stable@nongnu.org Signed-off-by: Markus Armbruster <armbru@redhat.com> --- net/net.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)