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1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2024 Isovalent */3 4#include "vmlinux.h"5#include <bpf/bpf_helpers.h>6#include <bpf/bpf_tracing.h>7#include "bpf_misc.h"8 9const volatile long foo = 42;10long bar;11long bart = 96;12 13SEC("tc/ingress")14__description("rodata/strtol: write rejected")15__failure __msg("write into map forbidden")16int tcx1(struct __sk_buff *skb)17{18 char buff[] = { '8', '4', '\0' };19 bpf_strtol(buff, sizeof(buff), 0, (long *)&foo);20 return TCX_PASS;21}22 23SEC("tc/ingress")24__description("bss/strtol: write accepted")25__success26int tcx2(struct __sk_buff *skb)27{28 char buff[] = { '8', '4', '\0' };29 bpf_strtol(buff, sizeof(buff), 0, &bar);30 return TCX_PASS;31}32 33SEC("tc/ingress")34__description("data/strtol: write accepted")35__success36int tcx3(struct __sk_buff *skb)37{38 char buff[] = { '8', '4', '\0' };39 bpf_strtol(buff, sizeof(buff), 0, &bart);40 return TCX_PASS;41}42 43SEC("tc/ingress")44__description("rodata/mtu: write rejected")45__failure __msg("write into map forbidden")46int tcx4(struct __sk_buff *skb)47{48 bpf_check_mtu(skb, skb->ifindex, (__u32 *)&foo, 0, 0);49 return TCX_PASS;50}51 52SEC("tc/ingress")53__description("bss/mtu: write accepted")54__success55int tcx5(struct __sk_buff *skb)56{57 bpf_check_mtu(skb, skb->ifindex, (__u32 *)&bar, 0, 0);58 return TCX_PASS;59}60 61SEC("tc/ingress")62__description("data/mtu: write accepted")63__success64int tcx6(struct __sk_buff *skb)65{66 bpf_check_mtu(skb, skb->ifindex, (__u32 *)&bart, 0, 0);67 return TCX_PASS;68}69 70static inline void write_fixed(volatile void *p, __u32 val)71{72 *(volatile __u32 *)p = val;73}74 75static inline void write_dyn(void *p, void *val, int len)76{77 bpf_copy_from_user(p, len, val);78}79 80SEC("tc/ingress")81__description("rodata/mark: write with unknown reg rejected")82__failure __msg("write into map forbidden")83int tcx7(struct __sk_buff *skb)84{85 write_fixed((void *)&foo, skb->mark);86 return TCX_PASS;87}88 89SEC("lsm.s/bprm_committed_creds")90__description("rodata/mark: write with unknown reg rejected")91__failure __msg("write into map forbidden")92int BPF_PROG(bprm, struct linux_binprm *bprm)93{94 write_dyn((void *)&foo, &bart, bpf_get_prandom_u32() & 3);95 return 0;96}97 98char LICENSE[] SEC("license") = "GPL";99