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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_sysctl_loop1.c')
-rw-r--r--tools/testing/selftests/bpf/progs/test_sysctl_loop1.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c b/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
new file mode 100644
index 000000000..553a282d8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_sysctl_loop1.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+
+#include <stdint.h>
+#include <string.h>
+
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+/* tcp_mem sysctl has only 3 ints, but this test is doing TCP_MEM_LOOPS */
+#define TCP_MEM_LOOPS 28 /* because 30 doesn't fit into 512 bytes of stack */
+#define MAX_ULONG_STR_LEN 7
+#define MAX_VALUE_STR_LEN (TCP_MEM_LOOPS * MAX_ULONG_STR_LEN)
+
+const char tcp_mem_name[] = "net/ipv4/tcp_mem/very_very_very_very_long_pointless_string";
+static __always_inline int is_tcp_mem(struct bpf_sysctl *ctx)
+{
+ unsigned char i;
+ char name[sizeof(tcp_mem_name)];
+ int ret;
+
+ memset(name, 0, sizeof(name));
+ ret = bpf_sysctl_get_name(ctx, name, sizeof(name), 0);
+ if (ret < 0 || ret != sizeof(tcp_mem_name) - 1)
+ return 0;
+
+#pragma clang loop unroll(disable)
+ for (i = 0; i < sizeof(tcp_mem_name); ++i)
+ if (name[i] != tcp_mem_name[i])
+ return 0;
+
+ return 1;
+}
+
+SEC("cgroup/sysctl")
+int sysctl_tcp_mem(struct bpf_sysctl *ctx)
+{
+ unsigned long tcp_mem[TCP_MEM_LOOPS] = {};
+ char value[MAX_VALUE_STR_LEN];
+ unsigned char i, off = 0;
+ /* a workaround to prevent compiler from generating
+ * codes verifier cannot handle yet.
+ */
+ volatile int ret;
+
+ if (ctx->write)
+ return 0;
+
+ if (!is_tcp_mem(ctx))
+ return 0;
+
+ ret = bpf_sysctl_get_current_value(ctx, value, MAX_VALUE_STR_LEN);
+ if (ret < 0 || ret >= MAX_VALUE_STR_LEN)
+ return 0;
+
+#pragma clang loop unroll(disable)
+ for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) {
+ ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0,
+ tcp_mem + i);
+ if (ret <= 0 || ret > MAX_ULONG_STR_LEN)
+ return 0;
+ off += ret & MAX_ULONG_STR_LEN;
+ }
+
+ return tcp_mem[0] < tcp_mem[1] && tcp_mem[1] < tcp_mem[2];
+}
+
+char _license[] SEC("license") = "GPL";