ebpf_nethooks.h File Reference

#include <stdint.h>

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Data Structures
struct	_bind_md
struct	bpf_sock_addr
	Data structure used as context for BPF_PROG_TYPE_CGROUP_SOCK_ADDR program type. More...
struct	_bpf_sock_ops

Macros
#define	SOCK_ADDR_EXT_HELPER_FN_BASE   0xFFFF

Typedefs
typedef enum _bind_operation	bind_operation_t
typedef struct _bind_md	bind_md_t
typedef enum _bind_action	bind_action_t
	Actions that can be returned by a bind hook program.
typedef bind_action_t	bind_hook_t(bind_md_t *context)
	Handle IPv4 and IPv6 socket bind() requests.
typedef enum _ebpf_sock_addr_verdict	ebpf_sock_addr_verdict_t
typedef struct bpf_sock_addr	bpf_sock_addr_t
	Data structure used as context for BPF_PROG_TYPE_CGROUP_SOCK_ADDR program type.
typedef ebpf_sock_addr_verdict_t	sock_addr_hook_t(bpf_sock_addr_t *context)
	Handle socket operation. Currently supports ingress/egress connection initialization.
typedef enum _bpf_sock_op_type	bpf_sock_op_type_t
typedef struct _bpf_sock_ops	bpf_sock_ops_t
typedef int	sock_ops_hook_t(bpf_sock_ops_t *context)
	Handle socket event notification. Currently notifies ingress/egress connection establishment and tear down.

Enumerations
enum	_bind_operation { BIND_OPERATION_BIND , BIND_OPERATION_POST_BIND , BIND_OPERATION_UNBIND }
enum	_bind_action {   BIND_PERMIT_SOFT , BIND_DENY , BIND_REDIRECT , BIND_PERMIT_HARD ,   BIND_PERMIT = BIND_PERMIT_SOFT }
	Actions that can be returned by a bind hook program. More...
enum	_ebpf_sock_addr_verdict { BPF_SOCK_ADDR_VERDICT_REJECT , BPF_SOCK_ADDR_VERDICT_PROCEED_SOFT , BPF_SOCK_ADDR_VERDICT_PROCEED_HARD }
enum	ebpf_sock_addr_helper_id_t { BPF_FUNC_sock_addr_get_current_pid_tgid = SOCK_ADDR_EXT_HELPER_FN_BASE + 1 , BPF_FUNC_sock_addr_set_redirect_context = SOCK_ADDR_EXT_HELPER_FN_BASE + 2 }
enum	_bpf_sock_op_type { BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB , BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB , BPF_SOCK_OPS_CONNECTION_DELETED_CB }

Functions
int	bpf_sock_addr_set_redirect_context (bpf_sock_addr_t *ctx, void *data, uint32_t data_size)
	Set a context for consumption by a user-mode application (sock_addr specific only). This function is not supported for the recv_accept hooks.

Macro Definition Documentation

SOCK_ADDR_EXT_HELPER_FN_BASE

#define SOCK_ADDR_EXT_HELPER_FN_BASE   0xFFFF

Typedef Documentation

bind_action_t

typedef enum _bind_action bind_action_t

Actions that can be returned by a bind hook program.

bind_hook_t

typedef bind_action_t bind_hook_t(bind_md_t *context)

Handle IPv4 and IPv6 socket bind() requests.

This function type defines the signature for eBPF programs that handle socket bind operations. The program is called before the bind operation completes and can inspect the socket metadata to make policy decisions about whether to allow, deny, or redirect the bind request.

The program can examine details such as the process ID, socket address, protocol, and interface information to implement custom bind policies. For redirect operations, the program can modify the socket_address field in the context to change the bind target.

Program type: EBPF_PROGRAM_TYPE_BIND

Note

The function must return one of the defined bind_action_t values.

Parameters

[in]

context

Socket metadata.

Return values

BIND_PERMIT_SOFT	Permit the bind operation (soft permit - allows lower-priority filters to override).
BIND_PERMIT_HARD	Permit the bind operation (hard permit - blocks lower-priority filters).
BIND_DENY	Deny the bind operation.
BIND_REDIRECT	Change the bind endpoint.

bind_md_t

typedef struct _bind_md bind_md_t

bind_operation_t

typedef enum _bind_operation bind_operation_t

bpf_sock_addr_t

typedef struct bpf_sock_addr bpf_sock_addr_t

Data structure used as context for BPF_PROG_TYPE_CGROUP_SOCK_ADDR program type.

bpf_sock_op_type_t

typedef enum _bpf_sock_op_type bpf_sock_op_type_t

bpf_sock_ops_t

typedef struct _bpf_sock_ops bpf_sock_ops_t

ebpf_sock_addr_verdict_t

typedef enum _ebpf_sock_addr_verdict ebpf_sock_addr_verdict_t

sock_addr_hook_t

typedef ebpf_sock_addr_verdict_t sock_addr_hook_t(bpf_sock_addr_t *context)

Handle socket operation. Currently supports ingress/egress connection initialization.

Program type: EBPF_PROGRAM_TYPE_CGROUP_SOCK_ADDR

Attach type(s): EBPF_ATTACH_TYPE_CGROUP_INET4_CONNECT EBPF_ATTACH_TYPE_CGROUP_INET6_CONNECT EBPF_ATTACH_TYPE_CGROUP_INET4_RECV_ACCEPT EBPF_ATTACH_TYPE_CGROUP_INET6_RECV_ACCEPT

Parameters

[in]

context

bpf_sock_addr_t

Return values

BPF_SOCK_ADDR_VERDICT_REJECT	Block the socket operation. Maps to a hard block in WFP.
BPF_SOCK_ADDR_VERDICT_PROCEED_SOFT	Allow the socket operation. Maps to a soft permit in WFP.
BPF_SOCK_ADDR_VERDICT_PROCEED_HARD	Allow the socket operation. Maps to a hard permit in WFP.

Any return value other than the ones mentioned above is treated as BPF_SOCK_ADDR_VERDICT_REJECT.

sock_ops_hook_t

typedef int sock_ops_hook_t(bpf_sock_ops_t *context)

Handle socket event notification. Currently notifies ingress/egress connection establishment and tear down.

Program type: EBPF_PROGRAM_TYPE_SOCK_OPS

Attach type(s): EBPF_ATTACH_TYPE_CGROUP_SOCK_OPS

Parameters

[in]

context

bpf_sock_ops_t

Returns

0 on success, or error value in case of failure.

Enumeration Type Documentation

_bind_action

enum _bind_action

Actions that can be returned by a bind hook program.

Enumerator
BIND_PERMIT_SOFT	Permit the bind operation (soft permit). Use this when you want to allow the operation but still permit other security policies or filters to make the final decision.
BIND_DENY	Deny the bind operation. The bind operation will be blocked.
BIND_REDIRECT	Change the bind endpoint. The bind operation is allowed but the target address/port may be modified by the eBPF program. The program should update the socket_address field in the bind_md_t context to specify the new target.
BIND_PERMIT_HARD	Permit the bind operation (hard permit). The bind operation is allowed and lower-priority filters or security policies cannot override this decision.
BIND_PERMIT	Backward compatibility alias for BIND_PERMIT_SOFT. Deprecated: Use BIND_PERMIT_SOFT instead for clarity about the permit behavior.

_bind_operation

enum _bind_operation

Enumerator
BIND_OPERATION_BIND	Entry to bind.
BIND_OPERATION_POST_BIND	After port allocation.
BIND_OPERATION_UNBIND	Release port.

_bpf_sock_op_type

enum _bpf_sock_op_type

Enumerator
BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB	Indicates when an active (outbound) connection is established.
BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB	Indicates when a passive (inbound) connection is established.
BPF_SOCK_OPS_CONNECTION_DELETED_CB	Indicates when a connection is deleted.

_ebpf_sock_addr_verdict

enum _ebpf_sock_addr_verdict

Enumerator
BPF_SOCK_ADDR_VERDICT_REJECT
BPF_SOCK_ADDR_VERDICT_PROCEED_SOFT
BPF_SOCK_ADDR_VERDICT_PROCEED_HARD

ebpf_sock_addr_helper_id_t

enum ebpf_sock_addr_helper_id_t

Enumerator
BPF_FUNC_sock_addr_get_current_pid_tgid
BPF_FUNC_sock_addr_set_redirect_context

Function Documentation

bpf_sock_addr_set_redirect_context()

int bpf_sock_addr_set_redirect_context	(	bpf_sock_addr_t *	ctx,
		void *	data,
		uint32_t	data_size
	)

Set a context for consumption by a user-mode application (sock_addr specific only). This function is not supported for the recv_accept hooks.

Parameters

[in]	ctx	Pointer to bpf_sock_addr_t context.
[in]	data	Pointer to data to store.
[in]	data_size	The size of the data to store.

Return values

0	The operation was successful.
<0	A failure occurred.