| Message ID | c1a88f471a8aa6d780dde690e76b73ba15618b6d.1675010984.git.leon@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v2] netlink: provide an ability to set default extack message | expand |
On Sun, Jan 29, 2023 at 06:51:37PM +0200, Leon Romanovsky wrote: > In netdev common pattern, extack pointer is forwarded to the drivers > to be filled with error message. However, the caller can easily > overwrite the filled message. > > Instead of adding multiple "if (!extack->_msg)" checks before any > NL_SET_ERR_MSG() call, which appears after call to the driver, let's > add new macro to common code. > > [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com>
On 29/01/2023 18:51, Leon Romanovsky wrote: > In netdev common pattern, extack pointer is forwarded to the drivers > to be filled with error message. However, the caller can easily > overwrite the filled message. > > Instead of adding multiple "if (!extack->_msg)" checks before any > NL_SET_ERR_MSG() call, which appears after call to the driver, let's > add new macro to common code. > > [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> > --- > Changelog: > v2: > * Removed () brackets around msg to fix compilation error. > v1: https://lore.kernel.org/all/d4843760219f20367c27472f084bd8aa729cf321.1674995155.git.leon@kernel.org > * Added special *_WEAK() macro instead of embedding same check in > NL_SET_ERR_MSG_MOD/NL_SET_ERR_MSG_FMT. > * Reuse same macro for XFRM code which triggered this patch. > v0: https://lore.kernel.org/all/2919eb55e2e9b92265a3ba600afc8137a901ae5f.1674760340.git.leon@kernel.org > --- > include/linux/netlink.h | 10 ++++++++++ > net/bridge/br_switchdev.c | 10 ++++------ > net/dsa/master.c | 4 +--- > net/dsa/slave.c | 4 +--- > net/xfrm/xfrm_device.c | 5 ++++- > 5 files changed, 20 insertions(+), 13 deletions(-) > Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Hello, On Sun, 2023-01-29 at 18:51 +0200, Leon Romanovsky wrote: > In netdev common pattern, extack pointer is forwarded to the drivers > to be filled with error message. However, the caller can easily > overwrite the filled message. > > Instead of adding multiple "if (!extack->_msg)" checks before any > NL_SET_ERR_MSG() call, which appears after call to the driver, let's > add new macro to common code. > > [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> I'm sorry for nit-picking, but checkpatch complains the author (leon@kernel.org) does not match the SoB tag. A v3 with a suitable From: tag should fix that. Thanks, Paolo
On Tue, Jan 31, 2023 at 12:47:03PM +0100, Paolo Abeni wrote: > Hello, > > On Sun, 2023-01-29 at 18:51 +0200, Leon Romanovsky wrote: > > In netdev common pattern, extack pointer is forwarded to the drivers > > to be filled with error message. However, the caller can easily > > overwrite the filled message. > > > > Instead of adding multiple "if (!extack->_msg)" checks before any > > NL_SET_ERR_MSG() call, which appears after call to the driver, let's > > add new macro to common code. > > > > [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal > > Signed-off-by: Leon Romanovsky <leonro@nvidia.com> > > I'm sorry for nit-picking, but checkpatch complains the author > (leon@kernel.org) does not match the SoB tag. A v3 with a suitable > From: tag should fix that. Sure, will resend. > > Thanks, > > Paolo >
diff --git a/include/linux/netlink.h b/include/linux/netlink.h index fa4d86da0ec7..c43ac7690eca 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -130,6 +130,16 @@ struct netlink_ext_ack { #define NL_SET_ERR_MSG_FMT_MOD(extack, fmt, args...) \ NL_SET_ERR_MSG_FMT((extack), KBUILD_MODNAME ": " fmt, ##args) +#define NL_SET_ERR_MSG_WEAK(extack, msg) do { \ + if ((extack) && !(extack)->_msg) \ + NL_SET_ERR_MSG((extack), msg); \ +} while (0) + +#define NL_SET_ERR_MSG_WEAK_MOD(extack, msg) do { \ + if ((extack) && !(extack)->_msg) \ + NL_SET_ERR_MSG_MOD((extack), msg); \ +} while (0) + #define NL_SET_BAD_ATTR_POLICY(extack, attr, pol) do { \ if ((extack)) { \ (extack)->bad_attr = (attr); \ diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c index 7eb6fd5bb917..de18e9c1d7a7 100644 --- a/net/bridge/br_switchdev.c +++ b/net/bridge/br_switchdev.c @@ -104,9 +104,8 @@ int br_switchdev_set_port_flag(struct net_bridge_port *p, return 0; if (err) { - if (extack && !extack->_msg) - NL_SET_ERR_MSG_MOD(extack, - "bridge flag offload is not supported"); + NL_SET_ERR_MSG_WEAK_MOD(extack, + "bridge flag offload is not supported"); return -EOPNOTSUPP; } @@ -115,9 +114,8 @@ int br_switchdev_set_port_flag(struct net_bridge_port *p, err = switchdev_port_attr_set(p->dev, &attr, extack); if (err) { - if (extack && !extack->_msg) - NL_SET_ERR_MSG_MOD(extack, - "error setting offload flag on port"); + NL_SET_ERR_MSG_WEAK_MOD(extack, + "error setting offload flag on port"); return err; } diff --git a/net/dsa/master.c b/net/dsa/master.c index 26d90140d271..1507b8cdb360 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -464,9 +464,7 @@ int dsa_master_lag_setup(struct net_device *lag_dev, struct dsa_port *cpu_dp, err = dsa_port_lag_join(cpu_dp, lag_dev, uinfo, extack); if (err) { - if (extack && !extack->_msg) - NL_SET_ERR_MSG_MOD(extack, - "CPU port failed to join LAG"); + NL_SET_ERR_MSG_WEAK_MOD(extack, "CPU port failed to join LAG"); goto out_master_teardown; } diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 6014ac3aad34..26c458f50ac6 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -2692,9 +2692,7 @@ static int dsa_slave_changeupper(struct net_device *dev, if (!err) dsa_bridge_mtu_normalization(dp); if (err == -EOPNOTSUPP) { - if (extack && !extack->_msg) - NL_SET_ERR_MSG_MOD(extack, - "Offloading not supported"); + NL_SET_ERR_MSG_WEAK_MOD(extack, "Offloading not supported"); err = 0; } err = notifier_from_errno(err); diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c index 562b9d951598..95f1436bf6a2 100644 --- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -325,8 +325,10 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, * authors to do not return -EOPNOTSUPP in packet offload mode. */ WARN_ON(err == -EOPNOTSUPP && is_packet_offload); - if (err != -EOPNOTSUPP || is_packet_offload) + if (err != -EOPNOTSUPP || is_packet_offload) { + NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state"); return err; + } } return 0; @@ -388,6 +390,7 @@ int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp, xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED; xdo->dir = 0; netdev_put(dev, &xdo->dev_tracker); + NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy"); return err; }
In netdev common pattern, extack pointer is forwarded to the drivers to be filled with error message. However, the caller can easily overwrite the filled message. Instead of adding multiple "if (!extack->_msg)" checks before any NL_SET_ERR_MSG() call, which appears after call to the driver, let's add new macro to common code. [1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal Signed-off-by: Leon Romanovsky <leonro@nvidia.com> --- Changelog: v2: * Removed () brackets around msg to fix compilation error. v1: https://lore.kernel.org/all/d4843760219f20367c27472f084bd8aa729cf321.1674995155.git.leon@kernel.org * Added special *_WEAK() macro instead of embedding same check in NL_SET_ERR_MSG_MOD/NL_SET_ERR_MSG_FMT. * Reuse same macro for XFRM code which triggered this patch. v0: https://lore.kernel.org/all/2919eb55e2e9b92265a3ba600afc8137a901ae5f.1674760340.git.leon@kernel.org --- include/linux/netlink.h | 10 ++++++++++ net/bridge/br_switchdev.c | 10 ++++------ net/dsa/master.c | 4 +--- net/dsa/slave.c | 4 +--- net/xfrm/xfrm_device.c | 5 ++++- 5 files changed, 20 insertions(+), 13 deletions(-)