root/tools/testing/selftests/bpf/progs/verifier_lwt.c
// SPDX-License-Identifier: GPL-2.0
/* Converted from tools/testing/selftests/bpf/verifier/lwt.c */

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"

SEC("lwt_in")
__description("invalid direct packet write for LWT_IN")
__failure __msg("cannot write into packet")
__naked void packet_write_for_lwt_in(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        *(u8*)(r2 + 0) = r2;                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_out")
__description("invalid direct packet write for LWT_OUT")
__failure __msg("cannot write into packet")
__naked void packet_write_for_lwt_out(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        *(u8*)(r2 + 0) = r2;                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_xmit")
__description("direct packet write for LWT_XMIT")
__success __retval(0)
__naked void packet_write_for_lwt_xmit(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        *(u8*)(r2 + 0) = r2;                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_in")
__description("direct packet read for LWT_IN")
__success __retval(0)
__naked void packet_read_for_lwt_in(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        r0 = *(u8*)(r2 + 0);                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_out")
__description("direct packet read for LWT_OUT")
__success __retval(0)
__naked void packet_read_for_lwt_out(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        r0 = *(u8*)(r2 + 0);                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_xmit")
__description("direct packet read for LWT_XMIT")
__success __retval(0)
__naked void packet_read_for_lwt_xmit(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        r0 = *(u8*)(r2 + 0);                            \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_xmit")
__description("overlapping checks for direct packet access")
__success __retval(0)
__naked void checks_for_direct_packet_access(void)
{
        asm volatile ("                                 \
        r2 = *(u32*)(r1 + %[__sk_buff_data]);           \
        r3 = *(u32*)(r1 + %[__sk_buff_data_end]);       \
        r0 = r2;                                        \
        r0 += 8;                                        \
        if r0 > r3 goto l0_%=;                          \
        r1 = r2;                                        \
        r1 += 6;                                        \
        if r1 > r3 goto l0_%=;                          \
        r0 = *(u16*)(r2 + 6);                           \
l0_%=:  r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
          __imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
        : __clobber_all);
}

SEC("lwt_xmit")
__description("make headroom for LWT_XMIT")
__success __retval(0)
__naked void make_headroom_for_lwt_xmit(void)
{
        asm volatile ("                                 \
        r6 = r1;                                        \
        r2 = 34;                                        \
        r3 = 0;                                         \
        call %[bpf_skb_change_head];                    \
        /* split for s390 to succeed */                 \
        r1 = r6;                                        \
        r2 = 42;                                        \
        r3 = 0;                                         \
        call %[bpf_skb_change_head];                    \
        r0 = 0;                                         \
        exit;                                           \
"       :
        : __imm(bpf_skb_change_head)
        : __clobber_all);
}

SEC("socket")
__description("invalid access of tc_classid for LWT_IN")
__failure __msg("invalid bpf_context access")
__failure_unpriv
__naked void tc_classid_for_lwt_in(void)
{
        asm volatile ("                                 \
        r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);     \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
        : __clobber_all);
}

SEC("socket")
__description("invalid access of tc_classid for LWT_OUT")
__failure __msg("invalid bpf_context access")
__failure_unpriv
__naked void tc_classid_for_lwt_out(void)
{
        asm volatile ("                                 \
        r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);     \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
        : __clobber_all);
}

SEC("socket")
__description("invalid access of tc_classid for LWT_XMIT")
__failure __msg("invalid bpf_context access")
__failure_unpriv
__naked void tc_classid_for_lwt_xmit(void)
{
        asm volatile ("                                 \
        r0 = *(u32*)(r1 + %[__sk_buff_tc_classid]);     \
        exit;                                           \
"       :
        : __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
        : __clobber_all);
}

SEC("lwt_in")
__description("check skb->tc_classid half load not permitted for lwt prog")
__failure __msg("invalid bpf_context access")
__naked void not_permitted_for_lwt_prog(void)
{
        asm volatile (
        "r0 = 0;"
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        "r0 = *(u16*)(r1 + %[__sk_buff_tc_classid]);"
#else
        "r0 = *(u16*)(r1 + %[__imm_0]);"
#endif
        "exit;"
        :
        : __imm_const(__imm_0, offsetof(struct __sk_buff, tc_classid) + 2),
          __imm_const(__sk_buff_tc_classid, offsetof(struct __sk_buff, tc_classid))
        : __clobber_all);
}

char _license[] SEC("license") = "GPL";