From 45d9b378e85f1b00ac047626827c68589168936c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 30 Apr 2017 21:46:45 -0700 Subject: [PATCH 1/4] netlink: add NULL-friendly helper for setting extended ACK message As we propagate extended ack reporting throughout various paths in the kernel it may be that the same function is called with the extended ack parameter passed as NULL. One place where that happens is in drivers which have a centralized reconfiguration function called both from ndos and from ethtool_ops. Add a new helper for setting the error message in such conditions. Existing helper is left as is to encourage propagating the ext act fully wherever possible. It also makes it clear in the code which messages may be lost due to ext ack being NULL. Signed-off-by: Jakub Kicinski Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/netlink.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 8d2a8924705c..c20395edf2de 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -92,6 +92,14 @@ struct netlink_ext_ack { (extack)->_msg = _msg; \ } while (0) +#define NL_MOD_TRY_SET_ERR_MSG(extack, msg) do { \ + static const char _msg[] = KBUILD_MODNAME ": " msg; \ + struct netlink_ext_ack *_extack = (extack); \ + \ + if (_extack) \ + _extack->_msg = _msg; \ +} while (0) + extern void netlink_kernel_release(struct sock *sk); extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); From ddf9f970764f4390aba767e77fddaaced4a6760d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 30 Apr 2017 21:46:46 -0700 Subject: [PATCH 2/4] xdp: propagate extended ack to XDP setup Drivers usually have a number of restrictions for running XDP - most common being buffer sizes, LRO and number of rings. Even though some drivers try to be helpful and print error messages experience shows that users don't often consult kernel logs on netlink errors. Try to use the new extended ack mechanism to carry the message back to user space. Signed-off-by: Jakub Kicinski Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/netdevice.h | 10 ++++++++-- net/core/dev.c | 5 ++++- net/core/rtnetlink.c | 13 ++++++++----- 3 files changed, 20 insertions(+), 8 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6847714a5ae3..9c23bd2efb56 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -813,11 +813,16 @@ enum xdp_netdev_command { XDP_QUERY_PROG, }; +struct netlink_ext_ack; + struct netdev_xdp { enum xdp_netdev_command command; union { /* XDP_SETUP_PROG */ - struct bpf_prog *prog; + struct { + struct bpf_prog *prog; + struct netlink_ext_ack *extack; + }; /* XDP_QUERY_PROG */ bool prog_attached; }; @@ -3291,7 +3296,8 @@ int dev_get_phys_port_id(struct net_device *dev, int dev_get_phys_port_name(struct net_device *dev, char *name, size_t len); int dev_change_proto_down(struct net_device *dev, bool proto_down); -int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags); +int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, + int fd, u32 flags); struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev); struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq, int *ret); diff --git a/net/core/dev.c b/net/core/dev.c index 8371a01eee87..35a06cebb282 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6854,12 +6854,14 @@ EXPORT_SYMBOL(dev_change_proto_down); /** * dev_change_xdp_fd - set or clear a bpf program for a device rx path * @dev: device + * @extact: netlink extended ack * @fd: new program fd or negative value to clear * @flags: xdp-related flags * * Set or clear a bpf program for a device */ -int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags) +int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, + int fd, u32 flags) { int (*xdp_op)(struct net_device *dev, struct netdev_xdp *xdp); const struct net_device_ops *ops = dev->netdev_ops; @@ -6892,6 +6894,7 @@ int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags) memset(&xdp, 0, sizeof(xdp)); xdp.command = XDP_SETUP_PROG; + xdp.extack = extack; xdp.prog = prog; err = xdp_op(dev, &xdp); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9031a6c8bfa7..6e67315ec368 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1919,6 +1919,7 @@ static int do_set_master(struct net_device *dev, int ifindex) #define DO_SETLINK_NOTIFY 0x03 static int do_setlink(const struct sk_buff *skb, struct net_device *dev, struct ifinfomsg *ifm, + struct netlink_ext_ack *extack, struct nlattr **tb, char *ifname, int status) { const struct net_device_ops *ops = dev->netdev_ops; @@ -2201,7 +2202,7 @@ static int do_setlink(const struct sk_buff *skb, } if (xdp[IFLA_XDP_FD]) { - err = dev_change_xdp_fd(dev, + err = dev_change_xdp_fd(dev, extack, nla_get_s32(xdp[IFLA_XDP_FD]), xdp_flags); if (err) @@ -2261,7 +2262,7 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) goto errout; - err = do_setlink(skb, dev, ifm, tb, ifname, 0); + err = do_setlink(skb, dev, ifm, extack, tb, ifname, 0); errout: return err; } @@ -2423,6 +2424,7 @@ EXPORT_SYMBOL(rtnl_create_link); static int rtnl_group_changelink(const struct sk_buff *skb, struct net *net, int group, struct ifinfomsg *ifm, + struct netlink_ext_ack *extack, struct nlattr **tb) { struct net_device *dev, *aux; @@ -2430,7 +2432,7 @@ static int rtnl_group_changelink(const struct sk_buff *skb, for_each_netdev_safe(net, dev, aux) { if (dev->group == group) { - err = do_setlink(skb, dev, ifm, tb, NULL, 0); + err = do_setlink(skb, dev, ifm, extack, tb, NULL, 0); if (err < 0) return err; } @@ -2576,14 +2578,15 @@ replay: status |= DO_SETLINK_NOTIFY; } - return do_setlink(skb, dev, ifm, tb, ifname, status); + return do_setlink(skb, dev, ifm, extack, tb, ifname, + status); } if (!(nlh->nlmsg_flags & NLM_F_CREATE)) { if (ifm->ifi_index == 0 && tb[IFLA_GROUP]) return rtnl_group_changelink(skb, net, nla_get_u32(tb[IFLA_GROUP]), - ifm, tb); + ifm, extack, tb); return -ENODEV; } From d957c0f711aaeaac6bbffd82098737ac10b7985d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 30 Apr 2017 21:46:47 -0700 Subject: [PATCH 3/4] nfp: make use of extended ack message reporting Try to carry error messages to the user via the netlink extended ack message attribute. Signed-off-by: Jakub Kicinski Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net.h | 3 ++- .../ethernet/netronome/nfp/nfp_net_common.c | 22 +++++++++++-------- .../ethernet/netronome/nfp/nfp_net_ethtool.c | 4 ++-- 3 files changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h index 38b41fdeaa8f..fcf81b3be830 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h @@ -818,7 +818,8 @@ nfp_net_irqs_assign(struct nfp_net *nn, struct msix_entry *irq_entries, unsigned int n); struct nfp_net_dp *nfp_net_clone_dp(struct nfp_net *nn); -int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *new); +int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *new, + struct netlink_ext_ack *extack); bool nfp_net_link_changed_read_clear(struct nfp_net *nn); int nfp_net_refresh_eth_port(struct nfp_net *nn); diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index b9f3548bb65f..db20376260f5 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -2524,24 +2524,27 @@ struct nfp_net_dp *nfp_net_clone_dp(struct nfp_net *nn) return new; } -static int nfp_net_check_config(struct nfp_net *nn, struct nfp_net_dp *dp) +static int +nfp_net_check_config(struct nfp_net *nn, struct nfp_net_dp *dp, + struct netlink_ext_ack *extack) { /* XDP-enabled tests */ if (!dp->xdp_prog) return 0; if (dp->fl_bufsz > PAGE_SIZE) { - nn_warn(nn, "MTU too large w/ XDP enabled\n"); + NL_MOD_TRY_SET_ERR_MSG(extack, "MTU too large w/ XDP enabled"); return -EINVAL; } if (dp->num_tx_rings > nn->max_tx_rings) { - nn_warn(nn, "Insufficient number of TX rings w/ XDP enabled\n"); + NL_MOD_TRY_SET_ERR_MSG(extack, "Insufficient number of TX rings w/ XDP enabled"); return -EINVAL; } return 0; } -int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *dp) +int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *dp, + struct netlink_ext_ack *extack) { int r, err; @@ -2553,7 +2556,7 @@ int nfp_net_ring_reconfig(struct nfp_net *nn, struct nfp_net_dp *dp) dp->num_r_vecs = max(dp->num_rx_rings, dp->num_stack_tx_rings); - err = nfp_net_check_config(nn, dp); + err = nfp_net_check_config(nn, dp, extack); if (err) goto exit_free_dp; @@ -2628,7 +2631,7 @@ static int nfp_net_change_mtu(struct net_device *netdev, int new_mtu) dp->mtu = new_mtu; - return nfp_net_ring_reconfig(nn, dp); + return nfp_net_ring_reconfig(nn, dp, NULL); } static void nfp_net_stat64(struct net_device *netdev, @@ -2944,9 +2947,10 @@ static int nfp_net_xdp_offload(struct nfp_net *nn, struct bpf_prog *prog) return ret; } -static int nfp_net_xdp_setup(struct nfp_net *nn, struct bpf_prog *prog) +static int nfp_net_xdp_setup(struct nfp_net *nn, struct netdev_xdp *xdp) { struct bpf_prog *old_prog = nn->dp.xdp_prog; + struct bpf_prog *prog = xdp->prog; struct nfp_net_dp *dp; int err; @@ -2969,7 +2973,7 @@ static int nfp_net_xdp_setup(struct nfp_net *nn, struct bpf_prog *prog) dp->rx_dma_off = prog ? XDP_PACKET_HEADROOM - nn->dp.rx_offset : 0; /* We need RX reconfig to remap the buffers (BIDIR vs FROM_DEV) */ - err = nfp_net_ring_reconfig(nn, dp); + err = nfp_net_ring_reconfig(nn, dp, xdp->extack); if (err) return err; @@ -2987,7 +2991,7 @@ static int nfp_net_xdp(struct net_device *netdev, struct netdev_xdp *xdp) switch (xdp->command) { case XDP_SETUP_PROG: - return nfp_net_xdp_setup(nn, xdp->prog); + return nfp_net_xdp_setup(nn, xdp); case XDP_QUERY_PROG: xdp->prog_attached = !!nn->dp.xdp_prog; return 0; diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c index a704efd4e314..abbb47e60cc3 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c @@ -309,7 +309,7 @@ static int nfp_net_set_ring_size(struct nfp_net *nn, u32 rxd_cnt, u32 txd_cnt) dp->rxd_cnt = rxd_cnt; dp->txd_cnt = txd_cnt; - return nfp_net_ring_reconfig(nn, dp); + return nfp_net_ring_reconfig(nn, dp, NULL); } static int nfp_net_set_ringparam(struct net_device *netdev, @@ -880,7 +880,7 @@ static int nfp_net_set_num_rings(struct nfp_net *nn, unsigned int total_rx, if (dp->xdp_prog) dp->num_tx_rings += total_rx; - return nfp_net_ring_reconfig(nn, dp); + return nfp_net_ring_reconfig(nn, dp, NULL); } static int nfp_net_set_channels(struct net_device *netdev, From 9861ce039c2a4ff3e50eb7c679dadc15a8469e3f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 30 Apr 2017 21:46:48 -0700 Subject: [PATCH 4/4] virtio_net: make use of extended ack message reporting Try to carry error messages to the user via the netlink extended ack message attribute. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7877551fe4e0..3d0bc484b3d7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1878,7 +1878,8 @@ err: return ret; } -static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) +static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, + struct netlink_ext_ack *extack) { unsigned long int max_sz = PAGE_SIZE - sizeof(struct padded_vnet_hdr); struct virtnet_info *vi = netdev_priv(dev); @@ -1890,16 +1891,17 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) || virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) || virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO)) { - netdev_warn(dev, "can't set XDP while host is implementing LRO, disable LRO first\n"); + NL_SET_ERR_MSG(extack, "can't set XDP while host is implementing LRO, disable LRO first"); return -EOPNOTSUPP; } if (vi->mergeable_rx_bufs && !vi->any_header_sg) { - netdev_warn(dev, "XDP expects header/data in single page, any_header_sg required\n"); + NL_SET_ERR_MSG(extack, "XDP expects header/data in single page, any_header_sg required"); return -EINVAL; } if (dev->mtu > max_sz) { + NL_SET_ERR_MSG(extack, "MTU too large to enable XDP"); netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz); return -EINVAL; } @@ -1910,6 +1912,7 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog) /* XDP requires extra queues for XDP_TX */ if (curr_qp + xdp_qp > vi->max_queue_pairs) { + NL_SET_ERR_MSG(extack, "Too few free TX rings available"); netdev_warn(dev, "request %i queues but max is %i\n", curr_qp + xdp_qp, vi->max_queue_pairs); return -ENOMEM; @@ -1971,7 +1974,7 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_xdp *xdp) { switch (xdp->command) { case XDP_SETUP_PROG: - return virtnet_xdp_set(dev, xdp->prog); + return virtnet_xdp_set(dev, xdp->prog, xdp->extack); case XDP_QUERY_PROG: xdp->prog_attached = virtnet_xdp_query(dev); return 0;