On 4/21/23 9:27 AM, Daan De Meyer wrote:
The unix socket address hooks do not support modifying the source
address so we skip source address checks when we're running a unix
socket address hook test.
Signed-off-by: Daan De Meyer <daan.j.demeyer@xxxxxxxxx>
---
tools/testing/selftests/bpf/bpf_kfuncs.h | 13 ++
.../selftests/bpf/prog_tests/section_names.c | 30 ++++
.../testing/selftests/bpf/progs/bindun_prog.c | 59 ++++++++
.../selftests/bpf/progs/connectun_prog.c | 53 +++++++
.../selftests/bpf/progs/recvmsgun_prog.c | 59 ++++++++
.../selftests/bpf/progs/sendmsgun_prog.c | 53 +++++++
tools/testing/selftests/bpf/test_sock_addr.c | 137 +++++++++++++++++-
7 files changed, 397 insertions(+), 7 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/bindun_prog.c
create mode 100644 tools/testing/selftests/bpf/progs/connectun_prog.c
create mode 100644 tools/testing/selftests/bpf/progs/recvmsgun_prog.c
create mode 100644 tools/testing/selftests/bpf/progs/sendmsgun_prog.c
diff --git a/tools/testing/selftests/bpf/bpf_kfuncs.h b/tools/testing/selftests/bpf/bpf_kfuncs.h
index 8c993ec8ceea..dbdec3d5152e 100644
--- a/tools/testing/selftests/bpf/bpf_kfuncs.h
+++ b/tools/testing/selftests/bpf/bpf_kfuncs.h
@@ -1,6 +1,8 @@
#ifndef __BPF_KFUNCS__
#define __BPF_KFUNCS__
+struct bpf_sock_addr_kern;
+
/* Description
* Initializes an skb-type dynptr
* Returns
@@ -35,4 +37,15 @@ extern void *bpf_dynptr_slice(const struct bpf_dynptr *ptr, __u32 offset,
extern void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *ptr, __u32 offset,
void *buffer, __u32 buffer__szk) __ksym;
+/* Description
+ * Modify the contents of a sockaddr.
+ * Returns__bpf_kfunc
+ * -EINVAL if the sockaddr family does not match, the sockaddr is too small or
+ * too big, 0 if the sockaddr was successfully modified.
+ */
+extern int bpf_sock_addr_set(struct bpf_sock_addr_kern *sa_kern,
+ const void *addr, __u32 addrlen__sz) __ksym;
It needs some negative tests, like
- addrlen__sz > UNIX_PATH_MAX for AF_UNIX test.
- addrlen__sz is larger than the size of addr in the stack.
diff --git a/tools/testing/selftests/bpf/progs/bindun_prog.c b/tools/testing/selftests/bpf/progs/bindun_prog.c
new file mode 100644
index 000000000000..60addb5a9c96
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bindun_prog.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+
+#include <string.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include "bpf_kfuncs.h"
+
+#ifndef AF_UNIX
+#define AF_UNIX 1
Move it to bpf_tracing_net.h. AF_INET[6] is already there.
+#endif
+
+#define DST_REWRITE_PATH "\0bpf_cgroup_unix_test_rewrite"
+
+void *bpf_cast_to_kern_ctx(void *) __ksym;
+
+SEC("cgroup/bindun")
+int bind_un_prog(struct bpf_sock_addr *ctx)
+{
+ struct bpf_sock *sk = ctx->sk;
+ struct bpf_sock_addr_kern *sa_kern = bpf_cast_to_kern_ctx(ctx);
+ struct sockaddr_un *sa_kern_unaddr;
+ struct sockaddr_un unaddr = {
+ .sun_family = AF_UNIX,
+ };
+ __u32 unaddrlen = offsetof(struct sockaddr_un, sun_path) +
+ sizeof(DST_REWRITE_PATH) - 1;
+ int ret;
+
+ if (!sk)
+ return 0;
+
+ if (sk->family != AF_UNIX)
+ return 0;
+
+ if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
+ return 0;
+
+ memcpy(unaddr.sun_path, DST_REWRITE_PATH, sizeof(DST_REWRITE_PATH) - 1);
+
+ ret = bpf_sock_addr_set(sa_kern, (struct sockaddr *) &unaddr, unaddrlen);
+ if (ret)
+ return 0;
+
+ if (sa_kern->uaddrlen != unaddrlen)
+ return 0;
+
+ sa_kern_unaddr = bpf_rdonly_cast(sa_kern->uaddr,
+ bpf_core_type_id_kernel(struct sockaddr_un));
+ if (memcmp(sa_kern_unaddr->sun_path, DST_REWRITE_PATH,
+ sizeof(DST_REWRITE_PATH) - 1) != 0)
+ return 0;
+
+ return 1;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/connectun_prog.c b/tools/testing/selftests/bpf/progs/connectun_prog.c
new file mode 100644
index 000000000000..ac7209bd326f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/connectun_prog.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+
+#include <string.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include "bpf_kfuncs.h"
+
+#ifndef AF_UNIX
+#define AF_UNIX 1
+#endif
+
+#define DST_REWRITE_PATH "\0bpf_cgroup_unix_test_rewrite"
+
+void *bpf_cast_to_kern_ctx(void *) __ksym;
Move it to bpf_kfuncs.h also?
