github.com/cilium/ebpf@v0.15.1-0.20240517100537-8079b37aa138/link/xdp.go (about)

     1  package link
     2  
     3  import (
     4  	"fmt"
     5  
     6  	"github.com/cilium/ebpf"
     7  )
     8  
     9  // XDPAttachFlags represents how XDP program will be attached to interface.
    10  type XDPAttachFlags uint32
    11  
    12  const (
    13  	// XDPGenericMode (SKB) links XDP BPF program for drivers which do
    14  	// not yet support native XDP.
    15  	XDPGenericMode XDPAttachFlags = 1 << (iota + 1)
    16  	// XDPDriverMode links XDP BPF program into the driver’s receive path.
    17  	XDPDriverMode
    18  	// XDPOffloadMode offloads the entire XDP BPF program into hardware.
    19  	XDPOffloadMode
    20  )
    21  
    22  type XDPOptions struct {
    23  	// Program must be an XDP BPF program.
    24  	Program *ebpf.Program
    25  
    26  	// Interface is the interface index to attach program to.
    27  	Interface int
    28  
    29  	// Flags is one of XDPAttachFlags (optional).
    30  	//
    31  	// Only one XDP mode should be set, without flag defaults
    32  	// to driver/generic mode (best effort).
    33  	Flags XDPAttachFlags
    34  }
    35  
    36  // AttachXDP links an XDP BPF program to an XDP hook.
    37  func AttachXDP(opts XDPOptions) (Link, error) {
    38  	if t := opts.Program.Type(); t != ebpf.XDP {
    39  		return nil, fmt.Errorf("invalid program type %s, expected XDP", t)
    40  	}
    41  
    42  	if opts.Interface < 1 {
    43  		return nil, fmt.Errorf("invalid interface index: %d", opts.Interface)
    44  	}
    45  
    46  	rawLink, err := AttachRawLink(RawLinkOptions{
    47  		Program: opts.Program,
    48  		Attach:  ebpf.AttachXDP,
    49  		Target:  opts.Interface,
    50  		Flags:   uint32(opts.Flags),
    51  	})
    52  
    53  	return rawLink, err
    54  }