With the syscall common attrs support for link_create, add syscall common attrs support for xdp link_create in order to report the invalid target ifindex error and the underlying driver's error.
Instead of passing bpf log to bpf_xdp_link_attach(), pass an extack to receive the underlying driver's error message. If pass bpf log to bpf_xdp_link_attach(), it will introduce bpf_verifier.h dependency for net/core/dev.c, which is not acceptable for maintainability. Signed-off-by: Leon Hwang <[email protected]> --- include/linux/netdevice.h | 3 ++- kernel/bpf/syscall.c | 6 +++++- net/core/dev.c | 9 +++++---- 3 files changed, 12 insertions(+), 6 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c0ae442c4344..6f7fec24ca5f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4440,7 +4440,8 @@ struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *d struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq, int *ret); -int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); +int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog, + struct netlink_ext_ack *extack); u8 dev_xdp_prog_count(struct net_device *dev); int netif_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf); int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index db870e795d04..ca72b35cdcc9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5865,6 +5865,7 @@ static int bpf_map_do_batch(const union bpf_attr *attr, static int link_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, bpfptr_t uattr_common, u32 size_common) { + struct netlink_ext_ack extack = {}; struct bpf_verifier_log *log; struct bpf_log_attr attr_log; struct bpf_prog *prog; @@ -5944,7 +5945,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_a break; #ifdef CONFIG_NET case BPF_PROG_TYPE_XDP: - ret = bpf_xdp_link_attach(attr, prog); + ret = bpf_xdp_link_attach(attr, prog, &extack); break; case BPF_PROG_TYPE_SCHED_CLS: if (attr->link_create.attach_type == BPF_TCX_INGRESS || @@ -5980,6 +5981,9 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_a if (ret < 0) { int err; + if (extack._msg) + bpf_log(log, "%s\n", extack._msg); + err = bpf_log_attr_finalize(&attr_log, log); ret = err ? err : ret; if (prog) diff --git a/net/core/dev.c b/net/core/dev.c index 1a09e7869118..4aa55259d5eb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10882,11 +10882,11 @@ static const struct bpf_link_ops bpf_xdp_link_lops = { .update_prog = bpf_xdp_link_update, }; -int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog, + struct netlink_ext_ack *extack) { struct net *net = current->nsproxy->net_ns; struct bpf_link_primer link_primer; - struct netlink_ext_ack extack = {}; struct bpf_xdp_link *link; struct net_device *dev; int err, fd; @@ -10895,6 +10895,7 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) dev = dev_get_by_index(net, attr->link_create.target_ifindex); if (!dev) { rtnl_unlock(); + NL_SET_ERR_MSG(extack, "Invalid target_ifindex."); return -EINVAL; } @@ -10916,14 +10917,14 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) } netdev_lock_ops(dev); - err = dev_xdp_attach_link(dev, &extack, link); + err = dev_xdp_attach_link(dev, extack, link); netdev_unlock_ops(dev); rtnl_unlock(); if (err) { link->dev = NULL; bpf_link_cleanup(&link_primer); - trace_bpf_xdp_link_attach_failed(extack._msg); + trace_bpf_xdp_link_attach_failed(extack->_msg); goto out_put_dev; } -- 2.55.0
