eBPF Helpers

eBPF Helpers sorted by Release Date

The following table provides a comprehensive overview of eBPF helper functions, organized by the Linux kernel version in which they were introduced, from 3.19 to 6.2. Each entry includes the helper’s name, the kernel version, a link to the corresponding commit in the Linux kernel Git repository, and a brief description of its functionality.

These helpers are critical for BPF programs, enabling tasks such as network packet manipulation, system tracing, and security policy enforcement. Sorted in ascending order by kernel version, the table highlights the evolution of BPF capabilities.

HELPER	KERNEL	COMMIT ID	DESCRIPTION
map_delete_elem	3.19	d0003ec01c66	Deletes an element from a BPF map by key.
map_lookup_elem	3.19	d0003ec01c66	Looks up an element in a BPF map by key, returning a pointer to the value.
map_update_elem	3.19	d0003ec01c66	Updates or inserts an element in a BPF map.
get_prandom_u32	4.1	03e69b508b6f	Returns a pseudo-random 32-bit integer.
get_smp_processor_id	4.1	c04167ce2ca0	Returns the ID of the current CPU.
ktime_get_ns	4.1	d9847d310ab4	Returns the current time in nanoseconds since boot.
l3_csum_replace	4.1	91bc4822c3d6	Replaces the layer 3 checksum in a packet.
l4_csum_replace	4.1	91bc4822c3d6	Replaces the layer 4 checksum in a packet.
probe_read	4.1	2541517c32be	Safely reads kernel or user memory into a buffer.
skb_store_bytes	4.1	91bc4822c3d6	Stores bytes into a packet at a specified offset.
trace_printk	4.1	9c959c863f82	Prints formatted debug output to the trace buffer.
clone_redirect	4.2	3896d655f4d4	Clones a packet and redirects it to an interface.
get_current_comm	4.2	ffeedafbf023	Returns the name of the current process.
get_current_pid_tgid	4.2	ffeedafbf023	Returns the PID and TGID of the current task.
get_current_uid_gid	4.2	ffeedafbf023	Returns the UID and GID of the current task.
tail_call	4.2	04fd61ab36ec	Jumps to another BPF program in the same map.
get_cgroup_classid	4.3	8d20aabe1c76	Returns the class ID of the current cgroup.
perf_event_read	4.3	35578d798400	Reads a performance counter value.
skb_get_tunnel_key	4.3	d3aa45ce6b94	Retrieves the tunnel key from a packet.
skb_set_tunnel_key	4.3	d3aa45ce6b94	Sets the tunnel key for a packet.
skb_vlan_pop	4.3	4e10df9a60d9	Removes a VLAN tag from a packet.
skb_vlan_push	4.3	4e10df9a60d9	Adds a VLAN tag to a packet.
get_route_realm	4.4	c46646d0484f	Returns the routing realm of a packet.
perf_event_output	4.4	a43eec304259	Outputs data to a perf event buffer.
redirect	4.4	27b29f63058d	Redirects a packet to a specified interface.
skb_load_bytes	4.5	05c74e5e53f6	Loads bytes from a packet into a buffer.
csum_diff	4.6	7d672345ed29	Computes checksum difference between two buffers.
get_stackid	4.6	d5a3b1f69186	Returns a unique ID for the current stack trace.
skb_get_tunnel_opt	4.6	14ca0751c96f	Retrieves tunnel options from a packet.
skb_set_tunnel_opt	4.6	14ca0751c96f	Sets tunnel options for a packet.
get_current_task	4.8	606274c5abd8	Returns a pointer to the current task structure.
get_hash_recalc	4.8	13c5c240f789	Recalculates the hash for a socket buffer.
probe_write_user	4.8	96ae52279594	Safely writes data to user space memory.
skb_change_proto	4.8	6578171a7ff0	Changes the protocol of a packet.
skb_change_type	4.8	d2485c4242a8	Changes the type of a packet.
skb_under_cgroup	4.8	4a482f34afcc	Checks if a packet belongs to a cgroup.
csum_update	4.9	36bbef52c7eb	Updates the checksum of a packet.
current_task_under_cgroup	4.9	60d20f9195b2	Checks if the current task is in a specified cgroup.
set_hash_invalid	4.9	7a4b28c6cc9f	Invalidates the hash of a socket buffer.
skb_change_tail	4.9	5293efe62df8	Adjusts the tail pointer of a packet.
skb_pull_data	4.9	36bbef52c7eb	Pulls data from a packet, adjusting pointers.
get_numa_node_id	4.10	2d0e30c30f84	Returns the NUMA node ID of the current CPU.
skb_change_head	4.10	3a0af8fd61f9	Adjusts the head pointer of a packet.
xdp_adjust_head	4.10	17bedab27231	Adjusts the head of an XDP buffer.
probe_read_str	4.11	a5e8c07059d0	Safely reads a null-terminated string from memory.
get_socket_cookie	4.12	91b8270f2a4d	Returns a unique cookie for a socket.
get_socket_uid	4.12	6acc5c291068	Returns the UID of a socket’s owner.
set_hash	4.13	ded092cd73c2	Sets the hash value for a socket buffer.
skb_adjust_room	4.13	2be7e212d541	Adjusts the room in a packet for data.
setsockopt	4.13	8c4b4c7e9ff0	Sets socket options for a socket.
redirect_map	4.14	97f91a7cf04f	Redirects a packet using a BPF map.
sock_map_update	4.14	174a79ff9515	Updates a socket map with a socket.
getsockopt	4.15	cd86d1fd2102	Retrieves socket options from a socket.
perf_event_read_value	4.15	908432ca84fc	Reads a performance counter with additional metadata.
perf_prog_read_value	4.15	4bebdc7a85aa	Reads performance program-specific values.
xdp_adjust_meta	4.15	de8f3a83b0a0	Adjusts the metadata of an XDP buffer.
override_return	4.16	9802d86585db	Overrides the return value of a function.
sock_ops_cb_flags_set	4.16	b13d88072172	Sets callback flags for socket operations.
bind	4.17	d74bad4e74ee	Binds a socket to an address.
msg_apply_bytes	4.17	2a100317c9eb	Applies bytes to a socket message.
msg_cork_bytes	4.17	91843d540a13	Corks bytes for a socket message.
msg_pull_data	4.17	015632bb30da	Pulls data from a socket message.
msg_redirect_map	4.17	4f738adba30a	Redirects a socket message using a BPF map.
fib_lookup	4.18	87f5fc7e48dd	Performs a FIB (Forwarding Information Base) lookup.
get_current_cgroup_id	4.18	bf6fa2c893c5	Returns the ID of the current cgroup.
get_stack	4.18	de2ff05f48af	Captures the current stack trace.
lwt_push_encap	4.18	fe94cc290f53	Pushes encapsulation headers for LWT (Lightweight Tunneling).
lwt_seg6_action	4.18	fe94cc290f53	Performs Segment Routing v6 actions.
lwt_seg6_adjust_srh	4.18	fe94cc290f53	Adjusts the Segment Routing Header (SRH).
lwt_seg6_store_bytes	4.18	fe94cc290f53	Stores bytes in a Segment Routing v6 packet.
rc_keydown	4.18	f4364dcfc86d	Sends a remote control key press event.
rc_repeat	4.18	f4364dcfc86d	Sends a remote control repeat event.
sk_redirect_hash	4.18	81110384441a	Redirects a socket using a hash-based map.
skb_cgroup_id	4.18	cb20b08ead40	Returns the cgroup ID of a packet.
skb_get_xfrm_state	4.18	12bed760a78d	Retrieves the XFRM (IPsec) state of a packet.
skb_load_bytes_relative	4.18	4e1ec56cdc59	Loads bytes from a packet relative to a header.
sock_hash_update	4.18	81110384441a	Updates a socket hash map.
xdp_adjust_tail	4.18	b32cc5b9a346	Adjusts the tail of an XDP buffer.
get_local_storage	4.19	cd3394317653	Retrieves per-CPU local storage for a task.
sk_select_reuseport	4.19	2dbb9b9e6df6	Selects a reuseport socket for load balancing.
skb_ancestor_cgroup_id	4.19	7723628101aa	Returns the cgroup ID of a packet’s ancestor.
map_peek_elem	4.20	f1a2e44a3aec	Peeks at an element in a queue or stack map.
map_pop_elem	4.20	f1a2e44a3aec	Pops an element from a queue or stack map.
map_push_elem	4.20	f1a2e44a3aec	Pushes an element onto a queue or stack map.
msg_push_data	4.20	6fff607e2f14	Pushes data into a socket message.
sk_lookup_tcp	4.20	6acc9b432e67	Looks up a TCP socket by address and port.
sk_lookup_udp	4.20	6acc9b432e67	Looks up a UDP socket by address and port.
sk_release	4.20	6acc9b432e67	Releases a socket reference.
msg_pop_data	5.0	7246d8ed4dcc	Pops data from a socket message.
rc_pointer_rel	5.0	01d3240a04f4	Adjusts the pointer for a remote control event.
get_listener_sock	5.1	dbafd7ddd623	Retrieves the listener socket for a connection.
sk_fullsock	5.1	46f8bc92758c	Returns the full socket structure.
skb_ecn_set_ce	5.1	f7c917ba11a6	Sets the ECN Congestion Experienced flag.
spin_lock	5.1	d83525ca62cf	Acquires a spinlock for synchronization.
spin_unlock	5.1	d83525ca62cf	Releases a spinlock.
tcp_sock	5.1	655a51e536c0	Returns the TCP socket structure.
sk_storage_delete	5.2	6ac99e8f23d4	Deletes storage associated with a socket.
sk_storage_get	5.2	6ac99e8f23d4	Retrieves storage associated with a socket.
skc_lookup_tcp	5.2	edbf8c01de5a	Looks up a TCP socket in a specific context.
strtol	5.2	d7a4cb9b6705	Converts a string to a long integer.
strtoul	5.2	d7a4cb9b6705	Converts a string to an unsigned long integer.
sysctl_get_current_value	5.2	1d11b3016cec	Retrieves the current sysctl value.
sysctl_get_name	5.2	808649fb787d	Retrieves the name of a sysctl.
sysctl_get_new_value	5.2	4e63acdff864	Retrieves the new sysctl value during a change.
sysctl_set_new_value	5.2	4e63acdff864	Sets a new sysctl value.
tcp_check_syncookie	5.2	399040847084	Checks a TCP SYN cookie for validity.
send_signal	5.3	8b401f9ed244	Sends a signal to a process.
tcp_gen_syncookie	5.3	70d66244317e	Generates a TCP SYN cookie.
jiffies64	5.5	5576b991e9c1	Returns the 64-bit jiffies counter.
probe_read_kernel	5.5	6ae08ae3dea2	Safely reads kernel memory.
probe_read_kernel_str	5.5	6ae08ae3dea2	Safely reads a kernel string.
probe_read_user	5.5	6ae08ae3dea2	Safely reads user space memory.
probe_read_user_str	5.5	6ae08ae3dea2	Safely reads a user space string.
send_signal_thread	5.5	8482941f0906	Sends a signal to a specific thread.
skb_output	5.5	a7658e1a4164	Outputs a packet to a network device.
tcp_send_ack	5.5	206057fe020a	Sends a TCP ACK packet.
get_current_ancestor_cgroup_id	5.6	b4490c5c4e02	Returns the ID of an ancestor cgroup.
read_branch_records	5.6	fff7b64355ea	Reads branch records for profiling.
sk_assign	5.6	cf7fbe660f2d	Assigns a socket to a specific context.
xdp_output	5.6	d831ee84bfc9	Outputs an XDP buffer to a network device.
csum_level	5.7	7cdec54f9713	Updates checksums for a specific protocol level.
get_netns_cookie	5.7	f318903c0bf4	Returns a cookie for the current network namespace.
get_ns_current_pid_tgid	5.7	b4490c5c4e02	Returns PID and TGID in a specific namespace.
seq_printf	5.7	492e639f0c22	Prints formatted output to a seq_file.
seq_write	5.7	492e639f0c22	Writes raw data to a seq_file.
sk_ancestor_cgroup_id	5.7	f307fa2cb4c9	Returns the ID of a socket’s ancestor cgroup.
sk_cgroup_id	5.7	f307fa2cb4c9	Returns the cgroup ID of a socket.
ktime_get_boot_ns	5.8	71d19214776e	Returns boot time in nanoseconds.
ringbuf_discard	5.8	457f44363a88	Discards a reserved ring buffer entry.
ringbuf_output	5.8	457f44363a88	Outputs data to a ring buffer.
ringbuf_query	5.8	457f44363a88	Queries ring buffer status.
ringbuf_reserve	5.8	457f44363a88	Reserves space in a ring buffer.
ringbuf_submit	5.8	457f44363a88	Submits a ring buffer entry.
get_task_stack	5.9	fa28dcb82a38	Retrieves the stack of a specified task.
skc_to_tcp_sock	5.9	478cfbdf5f13	Converts a socket context to a TCP socket.
skc_to_tcp_request_sock	5.9	478cfbdf5f13	Converts a socket context to a TCP request socket.
skc_to_tcp_timewait_sock	5.9	478cfbdf5f13	Converts a socket context to a TCP timewait socket.
skc_to_tcp6_sock	5.9	af7ec1383361	Converts a socket context to a TCPv6 socket.
skc_to_udp6_sock	5.9	0d4fad3e57df	Converts a socket context to a UDPv6 socket.
copy_from_user	5.10	07be4c4a3e7a	Copies data from user space to kernel space.
d_path	5.10	6e22ab9da793	Returns the path of a dentry.
inode_storage_delete	5.10	8ea636848aca	Deletes storage associated with an inode.
inode_storage_get	5.10	8ea636848aca	Retrieves storage associated with an inode.
load_hdr_opt	5.10	0813a841566f	Loads header options for a packet.
per_cpu_ptr	5.10	eaa6bcb71ef6	Returns a pointer to per-CPU data.
redirect_neigh	5.10	b4ab31414970	Redirects a packet to a neighbor.
redirect_peer	5.10	9aa1206e8f48	Redirects a packet to a peer.
reserve_hdr_opt	5.10	0813a841566f	Reserves space for header options.
seq_printf_btf	5.10	eb411377aed9	Prints BTF-formatted data to a seq_file.
skb_cgroup_classid	5.10	b426ce83baa7	Returns the class ID of a packet’s cgroup.
snprintf_btf	5.10	c4d0bfb45068	Formats BTF data into a string.
store_hdr_opt	5.10	0813a841566f	Stores header options for a packet.
this_cpu_ptr	5.10	63d9b80dcf2c	Returns a pointer to data on the current CPU.
bprm_opts_set	5.11	3f6719c7b62f	Sets options for a binary process.
get_current_task_btf	5.11	3ca1032ab7ab	Returns the current task in BTF format.
ima_inode_hash	5.11	27672f0d280a	Computes the IMA hash of an inode.
ktime_get_coarse_ns	5.11	d05512618056	Returns coarse-grained time in nanoseconds.
sock_from_file	5.11	4f19cab76136	Retrieves a socket from a file descriptor.
task_storage_delete	5.11	4cf1bc1f1045	Deletes storage associated with a task.
task_storage_get	5.11	4cf1bc1f1045	Retrieves storage associated with a task.
check_mtu	5.12	34b2021cc616	Checks the MTU for a network device.
for_each_map_elem	5.13	69c087ba6225	Iterates over elements in a BPF map.
snprintf	5.13	7b15523a989b	Formats a string with a specified buffer size.
btf_find_by_name_kind	5.14	3d78417b60fb	Finds a BTF type by name and kind.
sys_bpf	5.14	79a7f8bdb159	Executes a BPF system call from a program.
sys_close	5.14	3abea089246f	Closes a file descriptor.
get_attach_cookie	5.15	7adfc6c9b315	Retrieves a cookie for a BPF attachment.
get_func_ip	5.15	5d8b583d04ae	Returns the instruction pointer of a function.
task_pt_regs	5.15	dd6e10fbd9f	Returns the registers of a task.
timer_cancel	5.15	b00628b1c7d5	Cancels a BPF timer.
timer_init	5.15	b00628b1c7d5	Initializes a BPF timer.
timer_set_callback	5.15	b00628b1c7d5	Sets the callback for a BPF timer.
timer_start	5.15	b00628b1c7d5	Starts a BPF timer.
get_branch_snapshot	5.16	856c02dbce4f	Captures a snapshot of branch records.
kallsyms_lookup_name	5.16	d6aef08a872b	Looks up a kernel symbol by name.
skc_to_unix_sock	5.16	9eeb3aa33ae0	Converts a socket context to a UNIX socket.
trace_vprintk	5.16	10aceb629e19	Prints variable arguments to the trace buffer.
find_vma	5.17	7c7e3d31e785	Finds a virtual memory area for an address.
get_func_arg	5.17	f92c1e183604	Retrieves a function argument by index.
get_func_arg_cnt	5.17	f92c1e183604	Returns the number of function arguments.
get_func_ret	5.17	f92c1e183604	Retrieves the return value of a function.
loop	5.17	e6f2dd0f8067	Executes a bounded loop in a BPF program.
strncmp	5.17	c5fb19937455	Compares two strings up to a specified length.
copy_from_user_task	5.18	376040e47334	Copies data from a task’s user space.
get_retval	5.18	b44123b4a3dc	Retrieves the return value of a program.
ima_file_hash	5.18	174b16946e39	Computes the IMA hash of a file.
set_retval	5.18	b44123b4a3dc	Sets the return value of a program.
skb_set_tstamp	5.18	9bb984f28d5b	Sets the timestamp of a packet.
xdp_get_buff_len	5.18	0165cc817075	Returns the length of an XDP buffer.
xdp_load_bytes	5.18	3f364222d032	Loads bytes from an XDP buffer.
xdp_store_bytes	5.18	3f364222d032	Stores bytes in an XDP buffer.
dynptr_data	5.19	34d4ef5775f7	Retrieves data from a dynamic pointer.
dynptr_from_mem	5.19	263ae152e962	Creates a dynamic pointer from memory.
dynptr_read	5.19	13bbbfbea759	Reads data from a dynamic pointer.
dynptr_write	5.19	13bbbfbea759	Writes data to a dynamic pointer.
kptr_xchg	5.19	c0a5a21c25f3	Exchanges a kernel pointer atomically.
map_lookup_percpu_elem	5.19	07343110b293	Looks up a per-CPU element in a map.
ringbuf_discard_dynptr	5.19	bc34dee65a65	Discards a ring buffer entry via a dynamic pointer.
ringbuf_reserve_dynptr	5.19	bc34dee65a65	Reserves a ring buffer entry via a dynamic pointer.
ringbuf_submit_dynptr	5.19	bc34dee65a65	Submits a ring buffer entry via a dynamic pointer.
skc_to_mctcp_sock	5.19	3bc253c2e652	Converts a socket context to an MCTCP socket.
tcp_raw_check_syncookie_ipv4	6.0	33bf9885040c	Checks an IPv4 TCP SYN cookie in raw mode.
tcp_raw_check_syncookie_ipv6	6.0	33bf9885040c	Checks an IPv6 TCP SYN cookie in raw mode.
tcp_raw_gen_syncookie_ipv4	6.0	33bf9885040c	Generates an IPv4 TCP SYN cookie in raw mode.
tcp_raw_gen_syncookie_ipv6	6.0	33bf9885040c	Generates an IPv6 TCP SYN cookie in raw mode.
ktime_get_tai_ns	6.1	c8996c98f703	Returns TAI time in nanoseconds.
user_ringbuf_drain	6.1	205715673844	Drains a user-space ring buffer.
cgrp_storage_delete	6.2	c4bcfb38a95e	Deletes storage associated with a cgroup.
cgrp_storage_get	6.2	c4bcfb38a95e	Retrieves storage associated with a cgroup.