From: David Ahern <dsahern@gmail.com>
Date: Thu, 31 Aug 2017 15:05:50 -0700
Subject: samples/bpf: Update cgroup socket examples to use uid gid helper
Patch-mainline: v4.14-rc1
Git-commit: 0adc3dd90050538ac543c6c0bea8e8527a9e2e2c
References: bsc#1109837
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
samples/bpf/sock_flags_kern.c | 5 +++++
samples/bpf/test_cgrp2_sock.c | 12 +++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
--- a/samples/bpf/sock_flags_kern.c
+++ b/samples/bpf/sock_flags_kern.c
@@ -9,8 +9,13 @@ SEC("cgroup/sock1")
int bpf_prog1(struct bpf_sock *sk)
{
char fmt[] = "socket: family %d type %d protocol %d\n";
+ char fmt2[] = "socket: uid %u gid %u\n";
+ __u64 gid_uid = bpf_get_current_uid_gid();
+ __u32 uid = gid_uid & 0xffffffff;
+ __u32 gid = gid_uid >> 32;
bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
+ bpf_trace_printk(fmt2, sizeof(fmt2), uid, gid);
/* block PF_INET6, SOCK_RAW, IPPROTO_ICMPV6 sockets
* ie., make ping6 fail
--- a/samples/bpf/test_cgrp2_sock.c
+++ b/samples/bpf/test_cgrp2_sock.c
@@ -46,8 +46,18 @@ static int prog_load(__u32 idx, __u32 ma
/* set mark on socket */
struct bpf_insn prog_mark[] = {
- BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ /* get uid of process */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_get_current_uid_gid),
+ BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
+
+ /* if uid is 0, use given mark, else use the uid as the mark */
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, mark),
+
+ /* set the mark on the new socket */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, mark)),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, mark)),
};