[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC 1/1] Add BPF support to qemu
|
From: |
Sameeh Jubran |
|
Subject: |
Re: [Qemu-devel] [RFC 1/1] Add BPF support to qemu |
|
Date: |
Tue, 19 Jun 2018 17:46:53 +0300 |
On Tue, Jun 19, 2018 at 5:41 PM, Murilo Opsfelder Araujo <
address@hidden> wrote:
> On Tue, Jun 19, 2018 at 04:22:00PM +0300, Sameeh Jubran wrote:
> > From: Sameeh Jubran <address@hidden>
> >
> > This commit introduces wrappers around BPF syscalls to qemu. The Berkeley
> > Packet Filter (BPF) can be really usefull for packet filtering, tracing
> and
> > monitoring with very minimal overhead.
> >
> > Signed-off-by: Sameeh Jubran <address@hidden>
> > ---
> > MAINTAINERS | 7 +
> > bpf/Makefile.objs | 1 +
> > bpf/bpf_syscall.c | 98 ++++++
> > include/bpf/bpf_syscall.h | 35 +++
> > linux-headers/linux/bpf.h | 673 ++++++++++++++++++++++++++++++
> ++++++++++
> > scripts/update-linux-headers.sh | 3 +-
> > 6 files changed, 816 insertions(+), 1 deletion(-)
> > create mode 100644 bpf/Makefile.objs
> > create mode 100644 bpf/bpf_syscall.c
> > create mode 100644 include/bpf/bpf_syscall.h
> > create mode 100644 linux-headers/linux/bpf.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 0fb5f38f9f..ce3cd39121 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -2126,6 +2126,13 @@ F: hw/rdma/*
> > F: hw/rdma/vmw/*
> > F: docs/pvrdma.txt
> >
> > +
> > +BPF
> > +M: Sameeh Jubran <address@hidden>
> > +S: Maintained
> > +F: bpf/*
> > +F: include/bpf*
> > +
> > Build and test automation
> > -------------------------
> > Build and test automation
> > diff --git a/bpf/Makefile.objs b/bpf/Makefile.objs
> > new file mode 100644
> > index 0000000000..fc38d9b5c9
> > --- /dev/null
> > +++ b/bpf/Makefile.objs
> > @@ -0,0 +1 @@
> > +common-obj-y += bpf_syscall.o
>
> Why do we need to have this enabled by default?
>
> IMO, this should be configurable. For example, adding a new --enable-bpf
> to the
> ./configure script and accessing it via $(CONFIG_BPF) variable in
> Makefiles. Or
> something among these lines.
I agree, I did this as an RFC only. I will change that when I'll send v1 :)
Thanks!
>
> > diff --git a/bpf/bpf_syscall.c b/bpf/bpf_syscall.c
> > new file mode 100644
> > index 0000000000..efdcd57ae8
> > --- /dev/null
> > +++ b/bpf/bpf_syscall.c
> > @@ -0,0 +1,98 @@
> > +/*
> > + * BPF syscalls
> > + *
> > + * Based on bpf-syscall.c from iovisor/ply
> > + *
> > + * Authors:
> > + * Sameeh Jubran <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > + * the COPYING file in the top-level directory.
> > + *
> > + */
> > +
> > +#include <string.h>
> > +#include <unistd.h>
> > +#include <linux/bpf.h>
> > +#include <linux/version.h>
> > +#include <sys/syscall.h>
> > +
> > +#include "bpf/bpf_syscall.h"
> > +
> > +static __u64 ptr_to_u64(const void *ptr)
> > +{
> > + return (__u64) (unsigned long) ptr;
> > +}
> > +
> > +int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns,
> > + int insn_cnt, const char *license, unsigned
> kern_version,
> > + int log_level, char *bpf_log_buf, unsigned log_buf_size)
> > +{
> > + union bpf_attr attr;
> > +
> > + /* required since the kernel checks that unused fields and pad
> > + * bytes are zeroed */
> > + memset(&attr, 0, sizeof(attr));
> > +
> > + attr.kern_version = kern_version;
> > + attr.prog_type = type;
> > + attr.insns = ptr_to_u64(insns);
> > + attr.insn_cnt = insn_cnt;
> > + attr.license = ptr_to_u64(license);
> > + attr.log_buf = ptr_to_u64(bpf_log_buf);
> > + attr.log_size = log_buf_size;
> > + attr.log_level = log_level;
> > +
> > + return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
> > +}
> > +
> > +int bpf_map_create(enum bpf_map_type type, int key_size, int val_size,
> > + int entries)
> > +{
> > + union bpf_attr attr;
> > +
> > + /* required since the kernel checks that unused fields and pad
> > + * bytes are zeroed */
> > + memset(&attr, 0, sizeof(attr));
> > +
> > + attr.map_type = type;
> > + attr.key_size = key_size;
> > + attr.value_size = val_size;
> > + attr.max_entries = entries;
> > +
> > + return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
> > +}
> > +
> > +
> > +static int bpf_map_operation(enum bpf_cmd cmd, int fd,
> > + void *key, void *val_or_next, int flags)
> > +{
> > + union bpf_attr attr = {
> > + .map_fd = fd,
> > + .key = ptr_to_u64(key),
> > + .value = ptr_to_u64(val_or_next),
> > + .flags = flags,
> > + };
> > +
> > + return syscall(__NR_bpf, cmd, &attr, sizeof(attr));
> > +}
> > +
> > +int bpf_map_lookup(int fd, void *key, void *val)
> > +{
> > + return bpf_map_operation(BPF_MAP_LOOKUP_ELEM, fd, key, val, 0);
> > +}
> > +
> > +int bpf_map_update(int fd, void *key, void *val, int flags)
> > +{
> > + return bpf_map_operation(BPF_MAP_UPDATE_ELEM, fd, key, val, flags);
> > +}
> > +
> > +int bpf_map_delete(int fd, void *key)
> > +{
> > + return bpf_map_operation(BPF_MAP_DELETE_ELEM, fd, key, NULL, 0);
> > +}
> > +
> > +int bpf_map_next(int fd, void *key, void *next_key)
> > +{
> > + return bpf_map_operation(BPF_MAP_GET_NEXT_KEY, fd, key, next_key,
> 0);
> > +}
> > diff --git a/include/bpf/bpf_syscall.h b/include/bpf/bpf_syscall.h
> > new file mode 100644
> > index 0000000000..8d1f170343
> > --- /dev/null
> > +++ b/include/bpf/bpf_syscall.h
> > @@ -0,0 +1,35 @@
> > +/*
> > + * BPF syscalls
> > + *
> > + * Based on bpf-syscall.h from iovisor/ply
> > + *
> > + * Authors:
> > + * Sameeh Jubran <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > + * the COPYING file in the top-level directory.
> > + *
> > + */
> > +
> > +#ifndef BPF_SYSCALL_H
> > +#define BPF_SYSCALL_H
> > +
> > +#include <unistd.h>
> > +
> > +#include <linux/bpf.h>
> > +#include <linux/perf_event.h>
> > +#include <linux/version.h>
> > +
> > +int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns,
> > + int insn_cnt, const char *license, unsigned
> kern_version,
> > + int log_level, char *bpf_log_buf, unsigned
> log_buf_size);
> > +
> > +int bpf_map_create(enum bpf_map_type type, int key_size, int val_size,
> > + int entries);
> > +
> > +int bpf_map_lookup(int fd, void *key, void *val);
> > +int bpf_map_update(int fd, void *key, void *val, int flags);
> > +int bpf_map_delete(int fd, void *key);
> > +int bpf_map_next(int fd, void *key, void *next_key);
> > +
> > +#endif
> > diff --git a/linux-headers/linux/bpf.h b/linux-headers/linux/bpf.h
> > new file mode 100644
> > index 0000000000..d322ca1519
> > --- /dev/null
> > +++ b/linux-headers/linux/bpf.h
> > @@ -0,0 +1,673 @@
> > +/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of version 2 of the GNU General Public
> > + * License as published by the Free Software Foundation.
> > + */
> > +#ifndef __LINUX_BPF_H__
> > +#define __LINUX_BPF_H__
> > +
> > +#include <linux/types.h>
> > +#include <linux/bpf_common.h>
> > +
> > +/* Extended instruction set based on top of classic BPF */
> > +
> > +/* instruction classes */
> > +#define BPF_ALU64 0x07 /* alu mode in double word width */
> > +
> > +/* ld/ldx fields */
> > +#define BPF_DW 0x18 /* double word */
> > +#define BPF_XADD 0xc0 /* exclusive add */
> > +
> > +/* alu/jmp fields */
> > +#define BPF_MOV 0xb0 /* mov reg to reg */
> > +#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
> > +
> > +/* change endianness of a register */
> > +#define BPF_END 0xd0 /* flags for endianness
> conversion: */
> > +#define BPF_TO_LE 0x00 /* convert to little-endian */
> > +#define BPF_TO_BE 0x08 /* convert to big-endian */
> > +#define BPF_FROM_LE BPF_TO_LE
> > +#define BPF_FROM_BE BPF_TO_BE
> > +
> > +#define BPF_JNE 0x50 /* jump != */
> > +#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
> > +#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
> > +#define BPF_CALL 0x80 /* function call */
> > +#define BPF_EXIT 0x90 /* function return */
> > +
> > +/* Register numbers */
> > +enum {
> > + BPF_REG_0 = 0,
> > + BPF_REG_1,
> > + BPF_REG_2,
> > + BPF_REG_3,
> > + BPF_REG_4,
> > + BPF_REG_5,
> > + BPF_REG_6,
> > + BPF_REG_7,
> > + BPF_REG_8,
> > + BPF_REG_9,
> > + BPF_REG_10,
> > + __MAX_BPF_REG,
> > +};
> > +
> > +/* BPF has 10 general purpose 64-bit registers and stack frame. */
> > +#define MAX_BPF_REG __MAX_BPF_REG
> > +
> > +struct bpf_insn {
> > + __u8 code; /* opcode */
> > + __u8 dst_reg:4; /* dest register */
> > + __u8 src_reg:4; /* source register */
> > + __s16 off; /* signed offset */
> > + __s32 imm; /* signed immediate constant */
> > +};
> > +
> > +/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
> > +struct bpf_lpm_trie_key {
> > + __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6
> */
> > + __u8 data[0]; /* Arbitrary size */
> > +};
> > +
> > +/* BPF syscall commands, see bpf(2) man-page for details. */
> > +enum bpf_cmd {
> > + BPF_MAP_CREATE,
> > + BPF_MAP_LOOKUP_ELEM,
> > + BPF_MAP_UPDATE_ELEM,
> > + BPF_MAP_DELETE_ELEM,
> > + BPF_MAP_GET_NEXT_KEY,
> > + BPF_PROG_LOAD,
> > + BPF_OBJ_PIN,
> > + BPF_OBJ_GET,
> > + BPF_PROG_ATTACH,
> > + BPF_PROG_DETACH,
> > + BPF_PROG_TEST_RUN,
> > +};
> > +
> > +enum bpf_map_type {
> > + BPF_MAP_TYPE_UNSPEC,
> > + BPF_MAP_TYPE_HASH,
> > + BPF_MAP_TYPE_ARRAY,
> > + BPF_MAP_TYPE_PROG_ARRAY,
> > + BPF_MAP_TYPE_PERF_EVENT_ARRAY,
> > + BPF_MAP_TYPE_PERCPU_HASH,
> > + BPF_MAP_TYPE_PERCPU_ARRAY,
> > + BPF_MAP_TYPE_STACK_TRACE,
> > + BPF_MAP_TYPE_CGROUP_ARRAY,
> > + BPF_MAP_TYPE_LRU_HASH,
> > + BPF_MAP_TYPE_LRU_PERCPU_HASH,
> > + BPF_MAP_TYPE_LPM_TRIE,
> > + BPF_MAP_TYPE_ARRAY_OF_MAPS,
> > + BPF_MAP_TYPE_HASH_OF_MAPS,
> > +};
> > +
> > +enum bpf_prog_type {
> > + BPF_PROG_TYPE_UNSPEC,
> > + BPF_PROG_TYPE_SOCKET_FILTER,
> > + BPF_PROG_TYPE_KPROBE,
> > + BPF_PROG_TYPE_SCHED_CLS,
> > + BPF_PROG_TYPE_SCHED_ACT,
> > + BPF_PROG_TYPE_TRACEPOINT,
> > + BPF_PROG_TYPE_XDP,
> > + BPF_PROG_TYPE_PERF_EVENT,
> > + BPF_PROG_TYPE_CGROUP_SKB,
> > + BPF_PROG_TYPE_CGROUP_SOCK,
> > + BPF_PROG_TYPE_LWT_IN,
> > + BPF_PROG_TYPE_LWT_OUT,
> > + BPF_PROG_TYPE_LWT_XMIT,
> > +};
> > +
> > +enum bpf_attach_type {
> > + BPF_CGROUP_INET_INGRESS,
> > + BPF_CGROUP_INET_EGRESS,
> > + BPF_CGROUP_INET_SOCK_CREATE,
> > + __MAX_BPF_ATTACH_TYPE
> > +};
> > +
> > +#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
> > +
> > +/* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
> > + * to the given target_fd cgroup the descendent cgroup will be able to
> > + * override effective bpf program that was inherited from this cgroup
> > + */
> > +#define BPF_F_ALLOW_OVERRIDE (1U << 0)
> > +
> > +/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
> > + * verifier will perform strict alignment checking as if the kernel
> > + * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
> > + * and NET_IP_ALIGN defined to 2.
> > + */
> > +#define BPF_F_STRICT_ALIGNMENT (1U << 0)
> > +
> > +#define BPF_PSEUDO_MAP_FD 1
> > +
> > +/* flags for BPF_MAP_UPDATE_ELEM command */
> > +#define BPF_ANY 0 /* create new element or update existing
> */
> > +#define BPF_NOEXIST 1 /* create new element if it didn't exist */
> > +#define BPF_EXIST 2 /* update existing element */
> > +
> > +#define BPF_F_NO_PREALLOC (1U << 0)
> > +/* Instead of having one common LRU list in the
> > + * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
> > + * which can scale and perform better.
> > + * Note, the LRU nodes (including free nodes) cannot be moved
> > + * across different LRU lists.
> > + */
> > +#define BPF_F_NO_COMMON_LRU (1U << 1)
> > +
> > +union bpf_attr {
> > + struct { /* anonymous struct used by BPF_MAP_CREATE command */
> > + __u32 map_type; /* one of enum bpf_map_type */
> > + __u32 key_size; /* size of key in bytes */
> > + __u32 value_size; /* size of value in bytes */
> > + __u32 max_entries; /* max number of entries in a map
> */
> > + __u32 map_flags; /* prealloc or not */
> > + __u32 inner_map_fd; /* fd pointing to the inner map */
> > + };
> > +
> > + struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
> > + __u32 map_fd;
> > + __aligned_u64 key;
> > + union {
> > + __aligned_u64 value;
> > + __aligned_u64 next_key;
> > + };
> > + __u64 flags;
> > + };
> > +
> > + struct { /* anonymous struct used by BPF_PROG_LOAD command */
> > + __u32 prog_type; /* one of enum
> bpf_prog_type */
> > + __u32 insn_cnt;
> > + __aligned_u64 insns;
> > + __aligned_u64 license;
> > + __u32 log_level; /* verbosity level of
> verifier */
> > + __u32 log_size; /* size of user buffer */
> > + __aligned_u64 log_buf; /* user supplied buffer */
> > + __u32 kern_version; /* checked when
> prog_type=kprobe */
> > + __u32 prog_flags;
> > + };
> > +
> > + struct { /* anonymous struct used by BPF_OBJ_* commands */
> > + __aligned_u64 pathname;
> > + __u32 bpf_fd;
> > + };
> > +
> > + struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH
> commands */
> > + __u32 target_fd; /* container object to
> attach to */
> > + __u32 attach_bpf_fd; /* eBPF program to attach
> */
> > + __u32 attach_type;
> > + __u32 attach_flags;
> > + };
> > +
> > + struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
> > + __u32 prog_fd;
> > + __u32 retval;
> > + __u32 data_size_in;
> > + __u32 data_size_out;
> > + __aligned_u64 data_in;
> > + __aligned_u64 data_out;
> > + __u32 repeat;
> > + __u32 duration;
> > + } test;
> > +} __attribute__((aligned(8)));
> > +
> > +/* BPF helper function descriptions:
> > + *
> > + * void *bpf_map_lookup_elem(&map, &key)
> > + * Return: Map value or NULL
> > + *
> > + * int bpf_map_update_elem(&map, &key, &value, flags)
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_map_delete_elem(&map, &key)
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_probe_read(void *dst, int size, void *src)
> > + * Return: 0 on success or negative error
> > + *
> > + * u64 bpf_ktime_get_ns(void)
> > + * Return: current ktime
> > + *
> > + * int bpf_trace_printk(const char *fmt, int fmt_size, ...)
> > + * Return: length of buffer written or negative error
> > + *
> > + * u32 bpf_prandom_u32(void)
> > + * Return: random value
> > + *
> > + * u32 bpf_raw_smp_processor_id(void)
> > + * Return: SMP processor ID
> > + *
> > + * int bpf_skb_store_bytes(skb, offset, from, len, flags)
> > + * store bytes into packet
> > + * @skb: pointer to skb
> > + * @offset: offset within packet from skb->mac_header
> > + * @from: pointer where to copy bytes from
> > + * @len: number of bytes to store into packet
> > + * @flags: bit 0 - if true, recompute skb->csum
> > + * other bits - reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_l3_csum_replace(skb, offset, from, to, flags)
> > + * recompute IP checksum
> > + * @skb: pointer to skb
> > + * @offset: offset within packet where IP checksum is located
> > + * @from: old value of header field
> > + * @to: new value of header field
> > + * @flags: bits 0-3 - size of header field
> > + * other bits - reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_l4_csum_replace(skb, offset, from, to, flags)
> > + * recompute TCP/UDP checksum
> > + * @skb: pointer to skb
> > + * @offset: offset within packet where TCP/UDP checksum is located
> > + * @from: old value of header field
> > + * @to: new value of header field
> > + * @flags: bits 0-3 - size of header field
> > + * bit 4 - is pseudo header
> > + * other bits - reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_tail_call(ctx, prog_array_map, index)
> > + * jump into another BPF program
> > + * @ctx: context pointer passed to next program
> > + * @prog_array_map: pointer to map which type is
> BPF_MAP_TYPE_PROG_ARRAY
> > + * @index: index inside array that selects specific program to run
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_clone_redirect(skb, ifindex, flags)
> > + * redirect to another netdev
> > + * @skb: pointer to skb
> > + * @ifindex: ifindex of the net device
> > + * @flags: bit 0 - if set, redirect to ingress instead of egress
> > + * other bits - reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * u64 bpf_get_current_pid_tgid(void)
> > + * Return: current->tgid << 32 | current->pid
> > + *
> > + * u64 bpf_get_current_uid_gid(void)
> > + * Return: current_gid << 32 | current_uid
> > + *
> > + * int bpf_get_current_comm(char *buf, int size_of_buf)
> > + * stores current->comm into buf
> > + * Return: 0 on success or negative error
> > + *
> > + * u32 bpf_get_cgroup_classid(skb)
> > + * retrieve a proc's classid
> > + * @skb: pointer to skb
> > + * Return: classid if != 0
> > + *
> > + * int bpf_skb_vlan_push(skb, vlan_proto, vlan_tci)
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_vlan_pop(skb)
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_get_tunnel_key(skb, key, size, flags)
> > + * int bpf_skb_set_tunnel_key(skb, key, size, flags)
> > + * retrieve or populate tunnel metadata
> > + * @skb: pointer to skb
> > + * @key: pointer to 'struct bpf_tunnel_key'
> > + * @size: size of 'struct bpf_tunnel_key'
> > + * @flags: room for future extensions
> > + * Return: 0 on success or negative error
> > + *
> > + * u64 bpf_perf_event_read(&map, index)
> > + * Return: Number events read or error code
> > + *
> > + * int bpf_redirect(ifindex, flags)
> > + * redirect to another netdev
> > + * @ifindex: ifindex of the net device
> > + * @flags: bit 0 - if set, redirect to ingress instead of egress
> > + * other bits - reserved
> > + * Return: TC_ACT_REDIRECT
> > + *
> > + * u32 bpf_get_route_realm(skb)
> > + * retrieve a dst's tclassid
> > + * @skb: pointer to skb
> > + * Return: realm if != 0
> > + *
> > + * int bpf_perf_event_output(ctx, map, index, data, size)
> > + * output perf raw sample
> > + * @ctx: struct pt_regs*
> > + * @map: pointer to perf_event_array map
> > + * @index: index of event in the map
> > + * @data: data on stack to be output as raw data
> > + * @size: size of data
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_get_stackid(ctx, map, flags)
> > + * walk user or kernel stack and return id
> > + * @ctx: struct pt_regs*
> > + * @map: pointer to stack_trace map
> > + * @flags: bits 0-7 - numer of stack frames to skip
> > + * bit 8 - collect user stack instead of kernel
> > + * bit 9 - compare stacks by hash only
> > + * bit 10 - if two different stacks hash into the same
> stackid
> > + * discard old
> > + * other bits - reserved
> > + * Return: >= 0 stackid on success or negative error
> > + *
> > + * s64 bpf_csum_diff(from, from_size, to, to_size, seed)
> > + * calculate csum diff
> > + * @from: raw from buffer
> > + * @from_size: length of from buffer
> > + * @to: raw to buffer
> > + * @to_size: length of to buffer
> > + * @seed: optional seed
> > + * Return: csum result or negative error code
> > + *
> > + * int bpf_skb_get_tunnel_opt(skb, opt, size)
> > + * retrieve tunnel options metadata
> > + * @skb: pointer to skb
> > + * @opt: pointer to raw tunnel option data
> > + * @size: size of @opt
> > + * Return: option size
> > + *
> > + * int bpf_skb_set_tunnel_opt(skb, opt, size)
> > + * populate tunnel options metadata
> > + * @skb: pointer to skb
> > + * @opt: pointer to raw tunnel option data
> > + * @size: size of @opt
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_change_proto(skb, proto, flags)
> > + * Change protocol of the skb. Currently supported is v4 -> v6,
> > + * v6 -> v4 transitions. The helper will also resize the skb. eBPF
> > + * program is expected to fill the new headers via skb_store_bytes
> > + * and lX_csum_replace.
> > + * @skb: pointer to skb
> > + * @proto: new skb->protocol type
> > + * @flags: reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_change_type(skb, type)
> > + * Change packet type of skb.
> > + * @skb: pointer to skb
> > + * @type: new skb->pkt_type type
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_under_cgroup(skb, map, index)
> > + * Check cgroup2 membership of skb
> > + * @skb: pointer to skb
> > + * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
> > + * @index: index of the cgroup in the bpf_map
> > + * Return:
> > + * == 0 skb failed the cgroup2 descendant test
> > + * == 1 skb succeeded the cgroup2 descendant test
> > + * < 0 error
> > + *
> > + * u32 bpf_get_hash_recalc(skb)
> > + * Retrieve and possibly recalculate skb->hash.
> > + * @skb: pointer to skb
> > + * Return: hash
> > + *
> > + * u64 bpf_get_current_task(void)
> > + * Returns current task_struct
> > + * Return: current
> > + *
> > + * int bpf_probe_write_user(void *dst, void *src, int len)
> > + * safely attempt to write to a location
> > + * @dst: destination address in userspace
> > + * @src: source address on stack
> > + * @len: number of bytes to copy
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_current_task_under_cgroup(map, index)
> > + * Check cgroup2 membership of current task
> > + * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
> > + * @index: index of the cgroup in the bpf_map
> > + * Return:
> > + * == 0 current failed the cgroup2 descendant test
> > + * == 1 current succeeded the cgroup2 descendant test
> > + * < 0 error
> > + *
> > + * int bpf_skb_change_tail(skb, len, flags)
> > + * The helper will resize the skb to the given new size, to be used
> f.e.
> > + * with control messages.
> > + * @skb: pointer to skb
> > + * @len: new skb length
> > + * @flags: reserved
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_skb_pull_data(skb, len)
> > + * The helper will pull in non-linear data in case the skb is
> non-linear
> > + * and not all of len are part of the linear section. Only needed
> for
> > + * read/write with direct packet access.
> > + * @skb: pointer to skb
> > + * @len: len to make read/writeable
> > + * Return: 0 on success or negative error
> > + *
> > + * s64 bpf_csum_update(skb, csum)
> > + * Adds csum into skb->csum in case of CHECKSUM_COMPLETE.
> > + * @skb: pointer to skb
> > + * @csum: csum to add
> > + * Return: csum on success or negative error
> > + *
> > + * void bpf_set_hash_invalid(skb)
> > + * Invalidate current skb->hash.
> > + * @skb: pointer to skb
> > + *
> > + * int bpf_get_numa_node_id()
> > + * Return: Id of current NUMA node.
> > + *
> > + * int bpf_skb_change_head()
> > + * Grows headroom of skb and adjusts MAC header offset accordingly.
> > + * Will extends/reallocae as required automatically.
> > + * May change skb data pointer and will thus invalidate any check
> > + * performed for direct packet access.
> > + * @skb: pointer to skb
> > + * @len: length of header to be pushed in front
> > + * @flags: Flags (unused for now)
> > + * Return: 0 on success or negative error
> > + *
> > + * int bpf_xdp_adjust_head(xdp_md, delta)
> > + * Adjust the xdp_md.data by delta
> > + * @xdp_md: pointer to xdp_md
> > + * @delta: An positive/negative integer to be added to xdp_md.data
> > + * Return: 0 on success or negative on error
> > + *
> > + * int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
> > + * Copy a NUL terminated string from unsafe address. In case the
> string
> > + * length is smaller than size, the target is not padded with
> further NUL
> > + * bytes. In case the string length is larger than size, just
> count-1
> > + * bytes are copied and the last byte is set to NUL.
> > + * @dst: destination address
> > + * @size: maximum number of bytes to copy, including the trailing
> NUL
> > + * @unsafe_ptr: unsafe address
> > + * Return:
> > + * > 0 length of the string including the trailing NUL on success
> > + * < 0 error
> > + *
> > + * u64 bpf_get_socket_cookie(skb)
> > + * Get the cookie for the socket stored inside sk_buff.
> > + * @skb: pointer to skb
> > + * Return: 8 Bytes non-decreasing number on success or 0 if the
> socket
> > + * field is missing inside sk_buff
> > + *
> > + * u32 bpf_get_socket_uid(skb)
> > + * Get the owner uid of the socket stored inside sk_buff.
> > + * @skb: pointer to skb
> > + * Return: uid of the socket owner on success or overflowuid if
> failed.
> > + */
> > +#define __BPF_FUNC_MAPPER(FN) \
> > + FN(unspec), \
> > + FN(map_lookup_elem), \
> > + FN(map_update_elem), \
> > + FN(map_delete_elem), \
> > + FN(probe_read), \
> > + FN(ktime_get_ns), \
> > + FN(trace_printk), \
> > + FN(get_prandom_u32), \
> > + FN(get_smp_processor_id), \
> > + FN(skb_store_bytes), \
> > + FN(l3_csum_replace), \
> > + FN(l4_csum_replace), \
> > + FN(tail_call), \
> > + FN(clone_redirect), \
> > + FN(get_current_pid_tgid), \
> > + FN(get_current_uid_gid), \
> > + FN(get_current_comm), \
> > + FN(get_cgroup_classid), \
> > + FN(skb_vlan_push), \
> > + FN(skb_vlan_pop), \
> > + FN(skb_get_tunnel_key), \
> > + FN(skb_set_tunnel_key), \
> > + FN(perf_event_read), \
> > + FN(redirect), \
> > + FN(get_route_realm), \
> > + FN(perf_event_output), \
> > + FN(skb_load_bytes), \
> > + FN(get_stackid), \
> > + FN(csum_diff), \
> > + FN(skb_get_tunnel_opt), \
> > + FN(skb_set_tunnel_opt), \
> > + FN(skb_change_proto), \
> > + FN(skb_change_type), \
> > + FN(skb_under_cgroup), \
> > + FN(get_hash_recalc), \
> > + FN(get_current_task), \
> > + FN(probe_write_user), \
> > + FN(current_task_under_cgroup), \
> > + FN(skb_change_tail), \
> > + FN(skb_pull_data), \
> > + FN(csum_update), \
> > + FN(set_hash_invalid), \
> > + FN(get_numa_node_id), \
> > + FN(skb_change_head), \
> > + FN(xdp_adjust_head), \
> > + FN(probe_read_str), \
> > + FN(get_socket_cookie), \
> > + FN(get_socket_uid),
> > +
> > +/* integer value in 'imm' field of BPF_CALL instruction selects which
> helper
> > + * function eBPF program intends to call
> > + */
> > +#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
> > +enum bpf_func_id {
> > + __BPF_FUNC_MAPPER(__BPF_ENUM_FN)
> > + __BPF_FUNC_MAX_ID,
> > +};
> > +#undef __BPF_ENUM_FN
> > +
> > +/* All flags used by eBPF helper functions, placed here. */
> > +
> > +/* BPF_FUNC_skb_store_bytes flags. */
> > +#define BPF_F_RECOMPUTE_CSUM (1ULL << 0)
> > +#define BPF_F_INVALIDATE_HASH (1ULL << 1)
> > +
> > +/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
> > + * First 4 bits are for passing the header field size.
> > + */
> > +#define BPF_F_HDR_FIELD_MASK 0xfULL
> > +
> > +/* BPF_FUNC_l4_csum_replace flags. */
> > +#define BPF_F_PSEUDO_HDR (1ULL << 4)
> > +#define BPF_F_MARK_MANGLED_0 (1ULL << 5)
> > +#define BPF_F_MARK_ENFORCE (1ULL << 6)
> > +
> > +/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
> > +#define BPF_F_INGRESS (1ULL << 0)
> > +
> > +/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
> > +#define BPF_F_TUNINFO_IPV6 (1ULL << 0)
> > +
> > +/* BPF_FUNC_get_stackid flags. */
> > +#define BPF_F_SKIP_FIELD_MASK 0xffULL
> > +#define BPF_F_USER_STACK (1ULL << 8)
> > +#define BPF_F_FAST_STACK_CMP (1ULL << 9)
> > +#define BPF_F_REUSE_STACKID (1ULL << 10)
> > +
> > +/* BPF_FUNC_skb_set_tunnel_key flags. */
> > +#define BPF_F_ZERO_CSUM_TX (1ULL << 1)
> > +#define BPF_F_DONT_FRAGMENT (1ULL << 2)
> > +
> > +/* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
> > +#define BPF_F_INDEX_MASK 0xffffffffULL
> > +#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
> > +/* BPF_FUNC_perf_event_output for sk_buff input context. */
> > +#define BPF_F_CTXLEN_MASK (0xfffffULL << 32)
> > +
> > +/* user accessible mirror of in-kernel sk_buff.
> > + * new fields can only be added to the end of this structure
> > + */
> > +struct __sk_buff {
> > + __u32 len;
> > + __u32 pkt_type;
> > + __u32 mark;
> > + __u32 queue_mapping;
> > + __u32 protocol;
> > + __u32 vlan_present;
> > + __u32 vlan_tci;
> > + __u32 vlan_proto;
> > + __u32 priority;
> > + __u32 ingress_ifindex;
> > + __u32 ifindex;
> > + __u32 tc_index;
> > + __u32 cb[5];
> > + __u32 hash;
> > + __u32 tc_classid;
> > + __u32 data;
> > + __u32 data_end;
> > + __u32 napi_id;
> > +};
> > +
> > +struct bpf_tunnel_key {
> > + __u32 tunnel_id;
> > + union {
> > + __u32 remote_ipv4;
> > + __u32 remote_ipv6[4];
> > + };
> > + __u8 tunnel_tos;
> > + __u8 tunnel_ttl;
> > + __u16 tunnel_ext;
> > + __u32 tunnel_label;
> > +};
> > +
> > +/* Generic BPF return codes which all BPF program types may support.
> > + * The values are binary compatible with their TC_ACT_* counter-part to
> > + * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
> > + * programs.
> > + *
> > + * XDP is handled seprately, see XDP_*.
> > + */
> > +enum bpf_ret_code {
> > + BPF_OK = 0,
> > + /* 1 reserved */
> > + BPF_DROP = 2,
> > + /* 3-6 reserved */
> > + BPF_REDIRECT = 7,
> > + /* >127 are reserved for prog type specific return codes */
> > +};
> > +
> > +struct bpf_sock {
> > + __u32 bound_dev_if;
> > + __u32 family;
> > + __u32 type;
> > + __u32 protocol;
> > +};
> > +
> > +#define XDP_PACKET_HEADROOM 256
> > +
> > +/* User return codes for XDP prog type.
> > + * A valid XDP program must return one of these defined values. All
> other
> > + * return codes are reserved for future use. Unknown return codes will
> result
> > + * in packet drop.
> > + */
> > +enum xdp_action {
> > + XDP_ABORTED = 0,
> > + XDP_DROP,
> > + XDP_PASS,
> > + XDP_TX,
> > +};
> > +
> > +/* user accessible metadata for XDP packet hook
> > + * new fields must be added to the end of this structure
> > + */
> > +struct xdp_md {
> > + __u32 data;
> > + __u32 data_end;
> > +};
> > +
> > +#endif /* __LINUX_BPF_H__ */
> > diff --git a/scripts/update-linux-headers.sh b/scripts/update-linux-
> headers.sh
> > index feb75390aa..616855bb6e 100755
> > --- a/scripts/update-linux-headers.sh
> > +++ b/scripts/update-linux-headers.sh
> > @@ -126,7 +126,8 @@ done
> > rm -rf "$output/linux-headers/linux"
> > mkdir -p "$output/linux-headers/linux"
> > for header in kvm.h vfio.h vfio_ccw.h vhost.h \
> > - psci.h psp-sev.h userfaultfd.h; do
> > + psci.h psp-sev.h userfaultfd.h \
> > + bpf.h; do
> > cp "$tmpdir/include/linux/$header" "$output/linux-headers/linux"
> > done
> >
> > --
> > 2.13.6
> >
> >
>
> --
> Murilo
>
>
--
Respectfully,
*Sameeh Jubran*
*Linkedin <https://il.linkedin.com/pub/sameeh-jubran/87/747/a8a>*
*Software Engineer @ Daynix <http://www.daynix.com>.*