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linux/tools/testing/selftests/bpf/progs/test_sockmap_kern.h
John Fastabend f726e03564 bpf, sockmap: Test progs verifier error with latest clang
With a relatively recent clang (7090c10273119) and with this commit
to fix warnings in selftests (c8ed668593) that uses __sink(err)
to resolve unused variables. We get the following verifier error.

root@6e731a24b33a:/host/tools/testing/selftests/bpf# ./test_sockmap
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockmap_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockhash_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --

To fix simply remove the err value because its not actually used anywhere
in the testing. We can investigate the root cause later. Future patch should
probably actually test the err value as well. Although if the map updates
fail they will get caught eventually by userspace.

Fixes: c8ed668593 ("selftests/bpf: fix lots of silly mistakes pointed out by compiler")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-15-john.fastabend@gmail.com
2023-05-23 16:11:27 +02:00

380 lines
8.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io */
#include <stddef.h>
#include <string.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/pkt_cls.h>
#include <sys/socket.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include "bpf_misc.h"
/* Sockmap sample program connects a client and a backend together
* using cgroups.
*
* client:X <---> frontend:80 client:X <---> backend:80
*
* For simplicity we hard code values here and bind 1:1. The hard
* coded values are part of the setup in sockmap.sh script that
* is associated with this BPF program.
*
* The bpf_printk is verbose and prints information as connections
* are established and verdicts are decided.
*/
struct {
__uint(type, TEST_MAP_TYPE);
__uint(max_entries, 20);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
} sock_map SEC(".maps");
struct {
__uint(type, TEST_MAP_TYPE);
__uint(max_entries, 20);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
} sock_map_txmsg SEC(".maps");
struct {
__uint(type, TEST_MAP_TYPE);
__uint(max_entries, 20);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
} sock_map_redir SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
} sock_apply_bytes SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
} sock_cork_bytes SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 6);
__type(key, int);
__type(value, int);
} sock_bytes SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
} sock_redir_flags SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 3);
__type(key, int);
__type(value, int);
} sock_skb_opts SEC(".maps");
struct {
__uint(type, TEST_MAP_TYPE);
__uint(max_entries, 20);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
} tls_sock_map SEC(".maps");
SEC("sk_skb1")
int bpf_prog1(struct __sk_buff *skb)
{
int *f, two = 2;
f = bpf_map_lookup_elem(&sock_skb_opts, &two);
if (f && *f) {
return *f;
}
return skb->len;
}
SEC("sk_skb2")
int bpf_prog2(struct __sk_buff *skb)
{
__u32 lport = skb->local_port;
__u32 rport = skb->remote_port;
int len, *f, ret, zero = 0;
__u64 flags = 0;
__sink(rport);
if (lport == 10000)
ret = 10;
else
ret = 1;
len = (__u32)skb->data_end - (__u32)skb->data;
__sink(len);
f = bpf_map_lookup_elem(&sock_skb_opts, &zero);
if (f && *f) {
ret = 3;
flags = *f;
}
#ifdef SOCKMAP
return bpf_sk_redirect_map(skb, &sock_map, ret, flags);
#else
return bpf_sk_redirect_hash(skb, &sock_map, &ret, flags);
#endif
}
static inline void bpf_write_pass(struct __sk_buff *skb, int offset)
{
int err = bpf_skb_pull_data(skb, 6 + offset);
void *data_end;
char *c;
if (err)
return;
c = (char *)(long)skb->data;
data_end = (void *)(long)skb->data_end;
if (c + 5 + offset < data_end)
memcpy(c + offset, "PASS", 4);
}
SEC("sk_skb3")
int bpf_prog3(struct __sk_buff *skb)
{
int err, *f, ret = SK_PASS;
const int one = 1;
f = bpf_map_lookup_elem(&sock_skb_opts, &one);
if (f && *f) {
__u64 flags = 0;
ret = 0;
flags = *f;
err = bpf_skb_adjust_room(skb, -13, 0, 0);
if (err)
return SK_DROP;
err = bpf_skb_adjust_room(skb, 4, 0, 0);
if (err)
return SK_DROP;
bpf_write_pass(skb, 0);
#ifdef SOCKMAP
return bpf_sk_redirect_map(skb, &tls_sock_map, ret, flags);
#else
return bpf_sk_redirect_hash(skb, &tls_sock_map, &ret, flags);
#endif
}
f = bpf_map_lookup_elem(&sock_skb_opts, &one);
if (f && *f)
ret = SK_DROP;
err = bpf_skb_adjust_room(skb, 4, 0, 0);
if (err)
return SK_DROP;
bpf_write_pass(skb, 13);
return ret;
}
SEC("sockops")
int bpf_sockmap(struct bpf_sock_ops *skops)
{
__u32 lport, rport;
int op, ret;
op = (int) skops->op;
switch (op) {
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
lport = skops->local_port;
rport = skops->remote_port;
if (lport == 10000) {
ret = 1;
#ifdef SOCKMAP
bpf_sock_map_update(skops, &sock_map, &ret,
BPF_NOEXIST);
#else
bpf_sock_hash_update(skops, &sock_map, &ret,
BPF_NOEXIST);
#endif
}
break;
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
lport = skops->local_port;
rport = skops->remote_port;
if (bpf_ntohl(rport) == 10001) {
ret = 10;
#ifdef SOCKMAP
bpf_sock_map_update(skops, &sock_map, &ret,
BPF_NOEXIST);
#else
bpf_sock_hash_update(skops, &sock_map, &ret,
BPF_NOEXIST);
#endif
}
break;
default:
break;
}
return 0;
}
SEC("sk_msg1")
int bpf_prog4(struct sk_msg_md *msg)
{
int *bytes, zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5;
int *start, *end, *start_push, *end_push, *start_pop, *pop, err = 0;
bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
if (bytes)
bpf_msg_apply_bytes(msg, *bytes);
bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
if (bytes)
bpf_msg_cork_bytes(msg, *bytes);
start = bpf_map_lookup_elem(&sock_bytes, &zero);
end = bpf_map_lookup_elem(&sock_bytes, &one);
if (start && end)
bpf_msg_pull_data(msg, *start, *end, 0);
start_push = bpf_map_lookup_elem(&sock_bytes, &two);
end_push = bpf_map_lookup_elem(&sock_bytes, &three);
if (start_push && end_push) {
err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
if (err)
return SK_DROP;
}
start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
pop = bpf_map_lookup_elem(&sock_bytes, &five);
if (start_pop && pop)
bpf_msg_pop_data(msg, *start_pop, *pop, 0);
return SK_PASS;
}
SEC("sk_msg2")
int bpf_prog6(struct sk_msg_md *msg)
{
int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, key = 0;
int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop, *f;
int err = 0;
__u64 flags = 0;
bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
if (bytes)
bpf_msg_apply_bytes(msg, *bytes);
bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
if (bytes)
bpf_msg_cork_bytes(msg, *bytes);
start = bpf_map_lookup_elem(&sock_bytes, &zero);
end = bpf_map_lookup_elem(&sock_bytes, &one);
if (start && end)
bpf_msg_pull_data(msg, *start, *end, 0);
start_push = bpf_map_lookup_elem(&sock_bytes, &two);
end_push = bpf_map_lookup_elem(&sock_bytes, &three);
if (start_push && end_push) {
err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
if (err)
return SK_DROP;
}
start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
pop = bpf_map_lookup_elem(&sock_bytes, &five);
if (start_pop && pop)
bpf_msg_pop_data(msg, *start_pop, *pop, 0);
f = bpf_map_lookup_elem(&sock_redir_flags, &zero);
if (f && *f) {
key = 2;
flags = *f;
}
#ifdef SOCKMAP
return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags);
#else
return bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags);
#endif
}
SEC("sk_msg3")
int bpf_prog8(struct sk_msg_md *msg)
{
void *data_end = (void *)(long) msg->data_end;
void *data = (void *)(long) msg->data;
int ret = 0, *bytes, zero = 0;
bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
if (bytes) {
ret = bpf_msg_apply_bytes(msg, *bytes);
if (ret)
return SK_DROP;
} else {
return SK_DROP;
}
__sink(data_end);
__sink(data);
return SK_PASS;
}
SEC("sk_msg4")
int bpf_prog9(struct sk_msg_md *msg)
{
void *data_end = (void *)(long) msg->data_end;
void *data = (void *)(long) msg->data;
int ret = 0, *bytes, zero = 0;
bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
if (bytes) {
if (((__u64)data_end - (__u64)data) >= *bytes)
return SK_PASS;
ret = bpf_msg_cork_bytes(msg, *bytes);
if (ret)
return SK_DROP;
}
return SK_PASS;
}
SEC("sk_msg5")
int bpf_prog10(struct sk_msg_md *msg)
{
int *bytes, *start, *end, *start_push, *end_push, *start_pop, *pop;
int zero = 0, one = 1, two = 2, three = 3, four = 4, five = 5, err = 0;
bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);
if (bytes)
bpf_msg_apply_bytes(msg, *bytes);
bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);
if (bytes)
bpf_msg_cork_bytes(msg, *bytes);
start = bpf_map_lookup_elem(&sock_bytes, &zero);
end = bpf_map_lookup_elem(&sock_bytes, &one);
if (start && end)
bpf_msg_pull_data(msg, *start, *end, 0);
start_push = bpf_map_lookup_elem(&sock_bytes, &two);
end_push = bpf_map_lookup_elem(&sock_bytes, &three);
if (start_push && end_push) {
err = bpf_msg_push_data(msg, *start_push, *end_push, 0);
if (err)
return SK_PASS;
}
start_pop = bpf_map_lookup_elem(&sock_bytes, &four);
pop = bpf_map_lookup_elem(&sock_bytes, &five);
if (start_pop && pop)
bpf_msg_pop_data(msg, *start_pop, *pop, 0);
return SK_DROP;
}
char _license[] SEC("license") = "GPL";