program.go

Documentation: github.com/cilium/ebpf/link

     1  package link
     2  
     3  import (
     4  	"fmt"
     5  
     6  	"github.com/cilium/ebpf"
     7  	"github.com/cilium/ebpf/internal/sys"
     8  )
     9  
    10  type RawAttachProgramOptions struct {
    11  	// File descriptor to attach to. This differs for each attach type.
    12  	Target int
    13  	// Program to attach.
    14  	Program *ebpf.Program
    15  	// Program to replace (cgroups).
    16  	Replace *ebpf.Program
    17  	// Attach must match the attach type of Program (and Replace).
    18  	Attach ebpf.AttachType
    19  	// Flags control the attach behaviour. This differs for each attach type.
    20  	Flags uint32
    21  }
    22  
    23  // RawAttachProgram is a low level wrapper around BPF_PROG_ATTACH.
    24  //
    25  // You should use one of the higher level abstractions available in this
    26  // package if possible.
    27  func RawAttachProgram(opts RawAttachProgramOptions) error {
    28  	if err := haveProgAttach(); err != nil {
    29  		return err
    30  	}
    31  
    32  	var replaceFd uint32
    33  	if opts.Replace != nil {
    34  		replaceFd = uint32(opts.Replace.FD())
    35  	}
    36  
    37  	attr := sys.ProgAttachAttr{
    38  		TargetFd:     uint32(opts.Target),
    39  		AttachBpfFd:  uint32(opts.Program.FD()),
    40  		ReplaceBpfFd: replaceFd,
    41  		AttachType:   uint32(opts.Attach),
    42  		AttachFlags:  uint32(opts.Flags),
    43  	}
    44  
    45  	if err := sys.ProgAttach(&attr); err != nil {
    46  		return fmt.Errorf("can't attach program: %w", err)
    47  	}
    48  	return nil
    49  }
    50  
    51  type RawDetachProgramOptions struct {
    52  	Target  int
    53  	Program *ebpf.Program
    54  	Attach  ebpf.AttachType
    55  }
    56  
    57  // RawDetachProgram is a low level wrapper around BPF_PROG_DETACH.
    58  //
    59  // You should use one of the higher level abstractions available in this
    60  // package if possible.
    61  func RawDetachProgram(opts RawDetachProgramOptions) error {
    62  	if err := haveProgAttach(); err != nil {
    63  		return err
    64  	}
    65  
    66  	attr := sys.ProgDetachAttr{
    67  		TargetFd:    uint32(opts.Target),
    68  		AttachBpfFd: uint32(opts.Program.FD()),
    69  		AttachType:  uint32(opts.Attach),
    70  	}
    71  	if err := sys.ProgDetach(&attr); err != nil {
    72  		return fmt.Errorf("can't detach program: %w", err)
    73  	}
    74  
    75  	return nil
    76  }
    77
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