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Add mptcp-bpf-bkup

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Ycarus (Yannick Chabanois) 2024-06-11 20:06:20 +02:00
parent 0dd39de544
commit ec805f7cda
4 changed files with 866 additions and 0 deletions
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49
mptcp-bpf-bkup/Makefile Normal file
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#
# Copyright (C) 2023 Yannick Chabanois (Ycarus) for OpenMPTCProuter
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#
include $(TOPDIR)/rules.mk
include $(INCLUDE_DIR)/kernel.mk
PKG_NAME:=mptcp-bpf-bkup
PKG_VERSION:=$(LINUX_VERSION)
PKG_BUILD_DEPENDS:=HAS_BPF_TOOLCHAIN:bpf-headers
PKG_BUILD_PARALLEL:=1
PKG_RELEASE:=1
PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)
PKG_MAINTAINER:=Yannick Chabanois <contact@openmptcprouter.com>
include $(INCLUDE_DIR)/package.mk
include $(INCLUDE_DIR)/bpf_mptcp.mk
include $(INCLUDE_DIR)/nls.mk
define Package/mptcp-bpf-bkup
SECTION:=net
CATEGORY:=Network
TITLE:=MPTCP BPF bkup Scheduler
DEPENDS:=+libbpf +kmod-sched-core +kmod-sched-flower +kmod-sched-bpf $(BPF_DEPENDS)
endef
define Build/Prepare
mkdir -p $(PKG_BUILD_DIR)
$(CP) ./src/* $(PKG_BUILD_DIR)/
endef
define Build/Compile
$(call CompileBPF,$(PKG_BUILD_DIR)/mptcp_bpf_bkup.c)
endef
define Package/mptcp-bpf-bkup/install
$(INSTALL_DIR) \
$(1)/usr/share/bpf/scheduler
$(INSTALL_DATA) $(PKG_BUILD_DIR)/mptcp_bpf_bkup.o $(1)/usr/share/bpf/scheduler
endef
$(eval $(call BuildPackage,mptcp-bpf-bkup))

484
mptcp-bpf-bkup/src/bpf_core_read.h Normal file
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __BPF_CORE_READ_H__
#define __BPF_CORE_READ_H__
/*
* enum bpf_field_info_kind is passed as a second argument into
* __builtin_preserve_field_info() built-in to get a specific aspect of
* a field, captured as a first argument. __builtin_preserve_field_info(field,
* info_kind) returns __u32 integer and produces BTF field relocation, which
* is understood and processed by libbpf during BPF object loading. See
* selftests/bpf for examples.
*/
enum bpf_field_info_kind {
BPF_FIELD_BYTE_OFFSET = 0, /* field byte offset */
BPF_FIELD_BYTE_SIZE = 1,
BPF_FIELD_EXISTS = 2, /* field existence in target kernel */
BPF_FIELD_SIGNED = 3,
BPF_FIELD_LSHIFT_U64 = 4,
BPF_FIELD_RSHIFT_U64 = 5,
};
/* second argument to __builtin_btf_type_id() built-in */
enum bpf_type_id_kind {
BPF_TYPE_ID_LOCAL = 0, /* BTF type ID in local program */
BPF_TYPE_ID_TARGET = 1, /* BTF type ID in target kernel */
};
/* second argument to __builtin_preserve_type_info() built-in */
enum bpf_type_info_kind {
BPF_TYPE_EXISTS = 0, /* type existence in target kernel */
BPF_TYPE_SIZE = 1, /* type size in target kernel */
BPF_TYPE_MATCHES = 2, /* type match in target kernel */
};
/* second argument to __builtin_preserve_enum_value() built-in */
enum bpf_enum_value_kind {
BPF_ENUMVAL_EXISTS = 0, /* enum value existence in kernel */
BPF_ENUMVAL_VALUE = 1, /* enum value value relocation */
};
#define __CORE_RELO(src, field, info) \
__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define __CORE_BITFIELD_PROBE_READ(dst, src, fld) \
bpf_probe_read_kernel( \
(void *)dst, \
__CORE_RELO(src, fld, BYTE_SIZE), \
(const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
#else
/* semantics of LSHIFT_64 assumes loading values into low-ordered bytes, so
* for big-endian we need to adjust destination pointer accordingly, based on
* field byte size
*/
#define __CORE_BITFIELD_PROBE_READ(dst, src, fld) \
bpf_probe_read_kernel( \
(void *)dst + (8 - __CORE_RELO(src, fld, BYTE_SIZE)), \
__CORE_RELO(src, fld, BYTE_SIZE), \
(const void *)src + __CORE_RELO(src, fld, BYTE_OFFSET))
#endif
/*
* Extract bitfield, identified by s->field, and return its value as u64.
* All this is done in relocatable manner, so bitfield changes such as
* signedness, bit size, offset changes, this will be handled automatically.
* This version of macro is using bpf_probe_read_kernel() to read underlying
* integer storage. Macro functions as an expression and its return type is
* bpf_probe_read_kernel()'s return value: 0, on success, <0 on error.
*/
#define BPF_CORE_READ_BITFIELD_PROBED(s, field) ({ \
unsigned long long val = 0; \
\
__CORE_BITFIELD_PROBE_READ(&val, s, field); \
val <<= __CORE_RELO(s, field, LSHIFT_U64); \
if (__CORE_RELO(s, field, SIGNED)) \
val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64); \
else \
val = val >> __CORE_RELO(s, field, RSHIFT_U64); \
val; \
})
/*
* Extract bitfield, identified by s->field, and return its value as u64.
* This version of macro is using direct memory reads and should be used from
* BPF program types that support such functionality (e.g., typed raw
* tracepoints).
*/
#define BPF_CORE_READ_BITFIELD(s, field) ({ \
const void *p = (const void *)s + __CORE_RELO(s, field, BYTE_OFFSET); \
unsigned long long val; \
\
/* This is a so-called barrier_var() operation that makes specified \
* variable "a black box" for optimizing compiler. \
* It forces compiler to perform BYTE_OFFSET relocation on p and use \
* its calculated value in the switch below, instead of applying \
* the same relocation 4 times for each individual memory load. \
*/ \
asm volatile("" : "=r"(p) : "0"(p)); \
\
switch (__CORE_RELO(s, field, BYTE_SIZE)) { \
case 1: val = *(const unsigned char *)p; break; \
case 2: val = *(const unsigned short *)p; break; \
case 4: val = *(const unsigned int *)p; break; \
case 8: val = *(const unsigned long long *)p; break; \
} \
val <<= __CORE_RELO(s, field, LSHIFT_U64); \
if (__CORE_RELO(s, field, SIGNED)) \
val = ((long long)val) >> __CORE_RELO(s, field, RSHIFT_U64); \
else \
val = val >> __CORE_RELO(s, field, RSHIFT_U64); \
val; \
})
#define ___bpf_field_ref1(field) (field)
#define ___bpf_field_ref2(type, field) (((typeof(type) *)0)->field)
#define ___bpf_field_ref(args...) \
___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
/*
* Convenience macro to check that field actually exists in target kernel's.
* Returns:
* 1, if matching field is present in target kernel;
* 0, if no matching field found.
*
* Supports two forms:
* - field reference through variable access:
* bpf_core_field_exists(p->my_field);
* - field reference through type and field names:
* bpf_core_field_exists(struct my_type, my_field).
*/
#define bpf_core_field_exists(field...) \
__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
/*
* Convenience macro to get the byte size of a field. Works for integers,
* struct/unions, pointers, arrays, and enums.
*
* Supports two forms:
* - field reference through variable access:
* bpf_core_field_size(p->my_field);
* - field reference through type and field names:
* bpf_core_field_size(struct my_type, my_field).
*/
#define bpf_core_field_size(field...) \
__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_SIZE)
/*
* Convenience macro to get field's byte offset.
*
* Supports two forms:
* - field reference through variable access:
* bpf_core_field_offset(p->my_field);
* - field reference through type and field names:
* bpf_core_field_offset(struct my_type, my_field).
*/
#define bpf_core_field_offset(field...) \
__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_OFFSET)
/*
* Convenience macro to get BTF type ID of a specified type, using a local BTF
* information. Return 32-bit unsigned integer with type ID from program's own
* BTF. Always succeeds.
*/
#define bpf_core_type_id_local(type) \
__builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_LOCAL)
/*
* Convenience macro to get BTF type ID of a target kernel's type that matches
* specified local type.
* Returns:
* - valid 32-bit unsigned type ID in kernel BTF;
* - 0, if no matching type was found in a target kernel BTF.
*/
#define bpf_core_type_id_kernel(type) \
__builtin_btf_type_id(*(typeof(type) *)0, BPF_TYPE_ID_TARGET)
/*
* Convenience macro to check that provided named type
* (struct/union/enum/typedef) exists in a target kernel.
* Returns:
* 1, if such type is present in target kernel's BTF;
* 0, if no matching type is found.
*/
#define bpf_core_type_exists(type) \
__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
/*
* Convenience macro to check that provided named type
* (struct/union/enum/typedef) "matches" that in a target kernel.
* Returns:
* 1, if the type matches in the target kernel's BTF;
* 0, if the type does not match any in the target kernel
*/
#define bpf_core_type_matches(type) \
__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_MATCHES)
/*
* Convenience macro to get the byte size of a provided named type
* (struct/union/enum/typedef) in a target kernel.
* Returns:
* >= 0 size (in bytes), if type is present in target kernel's BTF;
* 0, if no matching type is found.
*/
#define bpf_core_type_size(type) \
__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_SIZE)
/*
* Convenience macro to check that provided enumerator value is defined in
* a target kernel.
* Returns:
* 1, if specified enum type and its enumerator value are present in target
* kernel's BTF;
* 0, if no matching enum and/or enum value within that enum is found.
*/
#define bpf_core_enum_value_exists(enum_type, enum_value) \
__builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_EXISTS)
/*
* Convenience macro to get the integer value of an enumerator value in
* a target kernel.
* Returns:
* 64-bit value, if specified enum type and its enumerator value are
* present in target kernel's BTF;
* 0, if no matching enum and/or enum value within that enum is found.
*/
#define bpf_core_enum_value(enum_type, enum_value) \
__builtin_preserve_enum_value(*(typeof(enum_type) *)enum_value, BPF_ENUMVAL_VALUE)
/*
* bpf_core_read() abstracts away bpf_probe_read_kernel() call and captures
* offset relocation for source address using __builtin_preserve_access_index()
* built-in, provided by Clang.
*
* __builtin_preserve_access_index() takes as an argument an expression of
* taking an address of a field within struct/union. It makes compiler emit
* a relocation, which records BTF type ID describing root struct/union and an
* accessor string which describes exact embedded field that was used to take
* an address. See detailed description of this relocation format and
* semantics in comments to struct bpf_field_reloc in libbpf_internal.h.
*
* This relocation allows libbpf to adjust BPF instruction to use correct
* actual field offset, based on target kernel BTF type that matches original
* (local) BTF, used to record relocation.
*/
#define bpf_core_read(dst, sz, src) \
bpf_probe_read_kernel(dst, sz, (const void *)__builtin_preserve_access_index(src))
/* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */
#define bpf_core_read_user(dst, sz, src) \
bpf_probe_read_user(dst, sz, (const void *)__builtin_preserve_access_index(src))
/*
* bpf_core_read_str() is a thin wrapper around bpf_probe_read_str()
* additionally emitting BPF CO-RE field relocation for specified source
* argument.
*/
#define bpf_core_read_str(dst, sz, src) \
bpf_probe_read_kernel_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
/* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use. */
#define bpf_core_read_user_str(dst, sz, src) \
bpf_probe_read_user_str(dst, sz, (const void *)__builtin_preserve_access_index(src))
#define ___concat(a, b) a ## b
#define ___apply(fn, n) ___concat(fn, n)
#define ___nth(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, __11, N, ...) N
/*
* return number of provided arguments; used for switch-based variadic macro
* definitions (see ___last, ___arrow, etc below)
*/
#define ___narg(...) ___nth(_, ##__VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
/*
* return 0 if no arguments are passed, N - otherwise; used for
* recursively-defined macros to specify termination (0) case, and generic
* (N) case (e.g., ___read_ptrs, ___core_read)
*/
#define ___empty(...) ___nth(_, ##__VA_ARGS__, N, N, N, N, N, N, N, N, N, N, 0)
#define ___last1(x) x
#define ___last2(a, x) x
#define ___last3(a, b, x) x
#define ___last4(a, b, c, x) x
#define ___last5(a, b, c, d, x) x
#define ___last6(a, b, c, d, e, x) x
#define ___last7(a, b, c, d, e, f, x) x
#define ___last8(a, b, c, d, e, f, g, x) x
#define ___last9(a, b, c, d, e, f, g, h, x) x
#define ___last10(a, b, c, d, e, f, g, h, i, x) x
#define ___last(...) ___apply(___last, ___narg(__VA_ARGS__))(__VA_ARGS__)
#define ___nolast2(a, _) a
#define ___nolast3(a, b, _) a, b
#define ___nolast4(a, b, c, _) a, b, c
#define ___nolast5(a, b, c, d, _) a, b, c, d
#define ___nolast6(a, b, c, d, e, _) a, b, c, d, e
#define ___nolast7(a, b, c, d, e, f, _) a, b, c, d, e, f
#define ___nolast8(a, b, c, d, e, f, g, _) a, b, c, d, e, f, g
#define ___nolast9(a, b, c, d, e, f, g, h, _) a, b, c, d, e, f, g, h
#define ___nolast10(a, b, c, d, e, f, g, h, i, _) a, b, c, d, e, f, g, h, i
#define ___nolast(...) ___apply(___nolast, ___narg(__VA_ARGS__))(__VA_ARGS__)
#define ___arrow1(a) a
#define ___arrow2(a, b) a->b
#define ___arrow3(a, b, c) a->b->c
#define ___arrow4(a, b, c, d) a->b->c->d
#define ___arrow5(a, b, c, d, e) a->b->c->d->e
#define ___arrow6(a, b, c, d, e, f) a->b->c->d->e->f
#define ___arrow7(a, b, c, d, e, f, g) a->b->c->d->e->f->g
#define ___arrow8(a, b, c, d, e, f, g, h) a->b->c->d->e->f->g->h
#define ___arrow9(a, b, c, d, e, f, g, h, i) a->b->c->d->e->f->g->h->i
#define ___arrow10(a, b, c, d, e, f, g, h, i, j) a->b->c->d->e->f->g->h->i->j
#define ___arrow(...) ___apply(___arrow, ___narg(__VA_ARGS__))(__VA_ARGS__)
#define ___type(...) typeof(___arrow(__VA_ARGS__))
#define ___read(read_fn, dst, src_type, src, accessor) \
read_fn((void *)(dst), sizeof(*(dst)), &((src_type)(src))->accessor)
/* "recursively" read a sequence of inner pointers using local __t var */
#define ___rd_first(fn, src, a) ___read(fn, &__t, ___type(src), src, a);
#define ___rd_last(fn, ...) \
___read(fn, &__t, ___type(___nolast(__VA_ARGS__)), __t, ___last(__VA_ARGS__));
#define ___rd_p1(fn, ...) const void *__t; ___rd_first(fn, __VA_ARGS__)
#define ___rd_p2(fn, ...) ___rd_p1(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p3(fn, ...) ___rd_p2(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p4(fn, ...) ___rd_p3(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p5(fn, ...) ___rd_p4(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p6(fn, ...) ___rd_p5(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p7(fn, ...) ___rd_p6(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p8(fn, ...) ___rd_p7(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___rd_p9(fn, ...) ___rd_p8(fn, ___nolast(__VA_ARGS__)) ___rd_last(fn, __VA_ARGS__)
#define ___read_ptrs(fn, src, ...) \
___apply(___rd_p, ___narg(__VA_ARGS__))(fn, src, __VA_ARGS__)
#define ___core_read0(fn, fn_ptr, dst, src, a) \
___read(fn, dst, ___type(src), src, a);
#define ___core_readN(fn, fn_ptr, dst, src, ...) \
___read_ptrs(fn_ptr, src, ___nolast(__VA_ARGS__)) \
___read(fn, dst, ___type(src, ___nolast(__VA_ARGS__)), __t, \
___last(__VA_ARGS__));
#define ___core_read(fn, fn_ptr, dst, src, a, ...) \
___apply(___core_read, ___empty(__VA_ARGS__))(fn, fn_ptr, dst, \
src, a, ##__VA_ARGS__)
/*
* BPF_CORE_READ_INTO() is a more performance-conscious variant of
* BPF_CORE_READ(), in which final field is read into user-provided storage.
* See BPF_CORE_READ() below for more details on general usage.
*/
#define BPF_CORE_READ_INTO(dst, src, a, ...) ({ \
___core_read(bpf_core_read, bpf_core_read, \
dst, (src), a, ##__VA_ARGS__) \
})
/*
* Variant of BPF_CORE_READ_INTO() for reading from user-space memory.
*
* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use.
*/
#define BPF_CORE_READ_USER_INTO(dst, src, a, ...) ({ \
___core_read(bpf_core_read_user, bpf_core_read_user, \
dst, (src), a, ##__VA_ARGS__) \
})
/* Non-CO-RE variant of BPF_CORE_READ_INTO() */
#define BPF_PROBE_READ_INTO(dst, src, a, ...) ({ \
___core_read(bpf_probe_read_kernel, bpf_probe_read_kernel, \
dst, (src), a, ##__VA_ARGS__) \
})
/* Non-CO-RE variant of BPF_CORE_READ_USER_INTO().
*
* As no CO-RE relocations are emitted, source types can be arbitrary and are
* not restricted to kernel types only.
*/
#define BPF_PROBE_READ_USER_INTO(dst, src, a, ...) ({ \
___core_read(bpf_probe_read_user, bpf_probe_read_user, \
dst, (src), a, ##__VA_ARGS__) \
})
/*
* BPF_CORE_READ_STR_INTO() does same "pointer chasing" as
* BPF_CORE_READ() for intermediate pointers, but then executes (and returns
* corresponding error code) bpf_core_read_str() for final string read.
*/
#define BPF_CORE_READ_STR_INTO(dst, src, a, ...) ({ \
___core_read(bpf_core_read_str, bpf_core_read, \
dst, (src), a, ##__VA_ARGS__) \
})
/*
* Variant of BPF_CORE_READ_STR_INTO() for reading from user-space memory.
*
* NOTE: see comments for BPF_CORE_READ_USER() about the proper types use.
*/
#define BPF_CORE_READ_USER_STR_INTO(dst, src, a, ...) ({ \
___core_read(bpf_core_read_user_str, bpf_core_read_user, \
dst, (src), a, ##__VA_ARGS__) \
})
/* Non-CO-RE variant of BPF_CORE_READ_STR_INTO() */
#define BPF_PROBE_READ_STR_INTO(dst, src, a, ...) ({ \
___core_read(bpf_probe_read_kernel_str, bpf_probe_read_kernel, \
dst, (src), a, ##__VA_ARGS__) \
})
/*
* Non-CO-RE variant of BPF_CORE_READ_USER_STR_INTO().
*
* As no CO-RE relocations are emitted, source types can be arbitrary and are
* not restricted to kernel types only.
*/
#define BPF_PROBE_READ_USER_STR_INTO(dst, src, a, ...) ({ \
___core_read(bpf_probe_read_user_str, bpf_probe_read_user, \
dst, (src), a, ##__VA_ARGS__) \
})
/*
* BPF_CORE_READ() is used to simplify BPF CO-RE relocatable read, especially
* when there are few pointer chasing steps.
* E.g., what in non-BPF world (or in BPF w/ BCC) would be something like:
* int x = s->a.b.c->d.e->f->g;
* can be succinctly achieved using BPF_CORE_READ as:
* int x = BPF_CORE_READ(s, a.b.c, d.e, f, g);
*
* BPF_CORE_READ will decompose above statement into 4 bpf_core_read (BPF
* CO-RE relocatable bpf_probe_read_kernel() wrapper) calls, logically
* equivalent to:
* 1. const void *__t = s->a.b.c;
* 2. __t = __t->d.e;
* 3. __t = __t->f;
* 4. return __t->g;
*
* Equivalence is logical, because there is a heavy type casting/preservation
* involved, as well as all the reads are happening through
* bpf_probe_read_kernel() calls using __builtin_preserve_access_index() to
* emit CO-RE relocations.
*
* N.B. Only up to 9 "field accessors" are supported, which should be more
* than enough for any practical purpose.
*/
#define BPF_CORE_READ(src, a, ...) ({ \
___type((src), a, ##__VA_ARGS__) __r; \
BPF_CORE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \
__r; \
})
/*
* Variant of BPF_CORE_READ() for reading from user-space memory.
*
* NOTE: all the source types involved are still *kernel types* and need to
* exist in kernel (or kernel module) BTF, otherwise CO-RE relocation will
* fail. Custom user types are not relocatable with CO-RE.
* The typical situation in which BPF_CORE_READ_USER() might be used is to
* read kernel UAPI types from the user-space memory passed in as a syscall
* input argument.
*/
#define BPF_CORE_READ_USER(src, a, ...) ({ \
___type((src), a, ##__VA_ARGS__) __r; \
BPF_CORE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \
__r; \
})
/* Non-CO-RE variant of BPF_CORE_READ() */
#define BPF_PROBE_READ(src, a, ...) ({ \
___type((src), a, ##__VA_ARGS__) __r; \
BPF_PROBE_READ_INTO(&__r, (src), a, ##__VA_ARGS__); \
__r; \
})
/*
* Non-CO-RE variant of BPF_CORE_READ_USER().
*
* As no CO-RE relocations are emitted, source types can be arbitrary and are
* not restricted to kernel types only.
*/
#define BPF_PROBE_READ_USER(src, a, ...) ({ \
___type((src), a, ##__VA_ARGS__) __r; \
BPF_PROBE_READ_USER_INTO(&__r, (src), a, ##__VA_ARGS__); \
__r; \
})
#endif

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mptcp-bpf-bkup/src/bpf_tcp_helpers.h Normal file
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BPF_TCP_HELPERS_H
#define __BPF_TCP_HELPERS_H
#include <stdbool.h>
#include <linux/types.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_tracing.h>
#define BPF_STRUCT_OPS(name, args...) \
SEC("struct_ops/"#name) \
BPF_PROG(name, args)
#ifndef SOL_TCP
#define SOL_TCP 6
#endif
#ifndef TCP_CA_NAME_MAX
#define TCP_CA_NAME_MAX 16
#endif
#define tcp_jiffies32 ((__u32)bpf_jiffies64())
struct sock_common {
unsigned char skc_state;
__u16 skc_num;
} __attribute__((preserve_access_index));
enum sk_pacing {
SK_PACING_NONE = 0,
SK_PACING_NEEDED = 1,
SK_PACING_FQ = 2,
};
struct sock {
struct sock_common __sk_common;
#define sk_state __sk_common.skc_state
int sk_sndbuf;
int sk_wmem_queued;
unsigned long sk_pacing_rate;
__u32 sk_pacing_status; /* see enum sk_pacing */
} __attribute__((preserve_access_index));
struct inet_sock {
struct sock sk;
} __attribute__((preserve_access_index));
struct inet_connection_sock {
struct inet_sock icsk_inet;
__u8 icsk_ca_state:6,
icsk_ca_setsockopt:1,
icsk_ca_dst_locked:1;
struct {
__u8 pending;
} icsk_ack;
__u64 icsk_ca_priv[104 / sizeof(__u64)];
} __attribute__((preserve_access_index));
struct request_sock {
struct sock_common __req_common;
} __attribute__((preserve_access_index));
struct tcp_sock {
struct inet_connection_sock inet_conn;
__u32 rcv_nxt;
__u32 snd_nxt;
__u32 snd_una;
__u32 window_clamp;
__u8 ecn_flags;
__u32 delivered;
__u32 delivered_ce;
__u32 snd_cwnd;
__u32 snd_cwnd_cnt;
__u32 snd_cwnd_clamp;
__u32 snd_ssthresh;
__u8 syn_data:1, /* SYN includes data */
syn_fastopen:1, /* SYN includes Fast Open option */
syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
syn_fastopen_ch:1, /* Active TFO re-enabling probe */
syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
save_syn:1, /* Save headers of SYN packet */
is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */
syn_smc:1; /* SYN includes SMC */
__u32 max_packets_out;
__u32 lsndtime;
__u32 prior_cwnd;
__u64 tcp_mstamp; /* most recent packet received/sent */
__u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
bool is_mptcp;
} __attribute__((preserve_access_index));
static __always_inline struct inet_connection_sock *inet_csk(const struct sock *sk)
{
return (struct inet_connection_sock *)sk;
}
static __always_inline void *inet_csk_ca(const struct sock *sk)
{
return (void *)inet_csk(sk)->icsk_ca_priv;
}
static __always_inline struct tcp_sock *tcp_sk(const struct sock *sk)
{
return (struct tcp_sock *)sk;
}
static __always_inline bool before(__u32 seq1, __u32 seq2)
{
return (__s32)(seq1-seq2) < 0;
}
#define after(seq2, seq1) before(seq1, seq2)
#define TCP_ECN_OK 1
#define TCP_ECN_QUEUE_CWR 2
#define TCP_ECN_DEMAND_CWR 4
#define TCP_ECN_SEEN 8
enum inet_csk_ack_state_t {
ICSK_ACK_SCHED = 1,
ICSK_ACK_TIMER = 2,
ICSK_ACK_PUSHED = 4,
ICSK_ACK_PUSHED2 = 8,
ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */
};
enum tcp_ca_event {
CA_EVENT_TX_START = 0,
CA_EVENT_CWND_RESTART = 1,
CA_EVENT_COMPLETE_CWR = 2,
CA_EVENT_LOSS = 3,
CA_EVENT_ECN_NO_CE = 4,
CA_EVENT_ECN_IS_CE = 5,
};
struct ack_sample {
__u32 pkts_acked;
__s32 rtt_us;
__u32 in_flight;
} __attribute__((preserve_access_index));
struct rate_sample {
__u64 prior_mstamp; /* starting timestamp for interval */
__u32 prior_delivered; /* tp->delivered at "prior_mstamp" */
__s32 delivered; /* number of packets delivered over interval */
long interval_us; /* time for tp->delivered to incr "delivered" */
__u32 snd_interval_us; /* snd interval for delivered packets */
__u32 rcv_interval_us; /* rcv interval for delivered packets */
long rtt_us; /* RTT of last (S)ACKed packet (or -1) */
int losses; /* number of packets marked lost upon ACK */
__u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */
__u32 prior_in_flight; /* in flight before this ACK */
bool is_app_limited; /* is sample from packet with bubble in pipe? */
bool is_retrans; /* is sample from retransmission? */
bool is_ack_delayed; /* is this (likely) a delayed ACK? */
} __attribute__((preserve_access_index));
#define TCP_CA_NAME_MAX 16
#define TCP_CONG_NEEDS_ECN 0x2
struct tcp_congestion_ops {
char name[TCP_CA_NAME_MAX];
__u32 flags;
/* initialize private data (optional) */
void (*init)(struct sock *sk);
/* cleanup private data (optional) */
void (*release)(struct sock *sk);
/* return slow start threshold (required) */
__u32 (*ssthresh)(struct sock *sk);
/* do new cwnd calculation (required) */
void (*cong_avoid)(struct sock *sk, __u32 ack, __u32 acked);
/* call before changing ca_state (optional) */
void (*set_state)(struct sock *sk, __u8 new_state);
/* call when cwnd event occurs (optional) */
void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
/* call when ack arrives (optional) */
void (*in_ack_event)(struct sock *sk, __u32 flags);
/* new value of cwnd after loss (required) */
__u32 (*undo_cwnd)(struct sock *sk);
/* hook for packet ack accounting (optional) */
void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample);
/* override sysctl_tcp_min_tso_segs */
__u32 (*min_tso_segs)(struct sock *sk);
/* returns the multiplier used in tcp_sndbuf_expand (optional) */
__u32 (*sndbuf_expand)(struct sock *sk);
/* call when packets are delivered to update cwnd and pacing rate,
* after all the ca_state processing. (optional)
*/
void (*cong_control)(struct sock *sk, const struct rate_sample *rs);
void *owner;
};
#define min(a, b) ((a) < (b) ? (a) : (b))
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min_not_zero(x, y) ({ \
typeof(x) __x = (x); \
typeof(y) __y = (y); \
__x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
static __always_inline bool tcp_in_slow_start(const struct tcp_sock *tp)
{
return tp->snd_cwnd < tp->snd_ssthresh;
}
static __always_inline bool tcp_is_cwnd_limited(const struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
/* If in slow start, ensure cwnd grows to twice what was ACKed. */
if (tcp_in_slow_start(tp))
return tp->snd_cwnd < 2 * tp->max_packets_out;
return !!BPF_CORE_READ_BITFIELD(tp, is_cwnd_limited);
}
static __always_inline bool tcp_cc_eq(const char *a, const char *b)
{
int i;
for (i = 0; i < TCP_CA_NAME_MAX; i++) {
if (a[i] != b[i])
return false;
if (!a[i])
break;
}
return true;
}
extern __u32 tcp_slow_start(struct tcp_sock *tp, __u32 acked) __ksym;
extern void tcp_cong_avoid_ai(struct tcp_sock *tp, __u32 w, __u32 acked) __ksym;
#define MPTCP_SCHED_NAME_MAX 16
#define MPTCP_SUBFLOWS_MAX 8
struct mptcp_subflow_context {
unsigned long avg_pacing_rate;
__u32 backup : 1;
__u8 stale_count;
struct sock *tcp_sock; /* tcp sk backpointer */
} __attribute__((preserve_access_index));
struct mptcp_sched_data {
bool reinject;
__u8 subflows;
} __attribute__((preserve_access_index));
struct mptcp_sched_ops {
char name[MPTCP_SCHED_NAME_MAX];
void (*init)(struct mptcp_sock *msk);
void (*release)(struct mptcp_sock *msk);
int (*get_subflow)(struct mptcp_sock *msk,
struct mptcp_sched_data *data);
void *owner;
};
struct mptcp_sock {
struct inet_connection_sock sk;
__u64 snd_nxt;
int snd_burst;
__u32 token;
struct sock *first;
char ca_name[TCP_CA_NAME_MAX];
} __attribute__((preserve_access_index));
extern void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
bool scheduled) __ksym;
extern struct mptcp_subflow_context *
bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) __ksym;
static __always_inline struct sock *
mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
{
return subflow->tcp_sock;
}
#endif

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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022, SUSE. */
#include <linux/bpf.h>
#include <limits.h>
#include "bpf_tcp_helpers.h"
char _license[] SEC("license") = "GPL";
SEC("struct_ops/mptcp_sched_bkup_init")
void BPF_PROG(mptcp_sched_bkup_init, struct mptcp_sock *msk)
{
}
SEC("struct_ops/mptcp_sched_bkup_release")
void BPF_PROG(mptcp_sched_bkup_release, struct mptcp_sock *msk)
{
}
int BPF_STRUCT_OPS(bpf_bkup_get_subflow, struct mptcp_sock *msk,
struct mptcp_sched_data *data)
{
int nr = -1;
for (int i = 0; i < data->subflows && i < MPTCP_SUBFLOWS_MAX; i++) {
struct mptcp_subflow_context *subflow;
subflow = bpf_mptcp_subflow_ctx_by_pos(data, i);
if (!subflow)
break;
if (!BPF_CORE_READ_BITFIELD_PROBED(subflow, backup)) {
nr = i;
break;
}
}
if (nr != -1) {
mptcp_subflow_set_scheduled(bpf_mptcp_subflow_ctx_by_pos(data, nr), true);
return -1;
}
return 0;
}
SEC(".struct_ops")
struct mptcp_sched_ops bkup = {
.init = (void *)mptcp_sched_bkup_init,
.release = (void *)mptcp_sched_bkup_release,
.get_subflow = (void *)bpf_bkup_get_subflow,
.name = "bpf_bkup",
};