The sk_lookup hook allows installing multiple BPF programs
simultaneously and has defined semantics. We therefore need
to be able to test multiple programs with one PROG_TEST_RUN
call. Extend the UAPI to include a prog_fds array which
enables this case. Passing an array with a single fd falls
back to current behaviour. Program types that allow multiple
programs have to provide a new test_run_array callback.
Signed-off-by: Lorenz Bauer <l...@cloudflare.com>
---
include/linux/bpf-netns.h | 2 +
include/linux/bpf.h | 3 ++
include/uapi/linux/bpf.h | 6 ++-
kernel/bpf/net_namespace.c | 2 +-
kernel/bpf/syscall.c | 73 ++++++++++++++++++++++++++++++----
tools/include/uapi/linux/bpf.h | 6 ++-
6 files changed, 81 insertions(+), 11 deletions(-)
diff --git a/include/linux/bpf-netns.h b/include/linux/bpf-netns.h
index 722f799c1a2e..f34800cd7017 100644
--- a/include/linux/bpf-netns.h
+++ b/include/linux/bpf-netns.h
@@ -5,6 +5,8 @@
#include <linux/mutex.h>
#include <uapi/linux/bpf.h>
+#define BPF_SK_LOOKUP_MAX_PROGS 64
+
enum netns_bpf_attach_type {
NETNS_BPF_INVALID = -1,
NETNS_BPF_FLOW_DISSECTOR = 0,
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 875f6bc4bf1d..67c21c8ba7cc 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -26,6 +26,7 @@ struct bpf_verifier_env;
struct bpf_verifier_log;
struct perf_event;
struct bpf_prog;
+struct bpf_prog_array;
struct bpf_prog_aux;
struct bpf_map;
struct sock;
@@ -437,6 +438,8 @@ bpf_ctx_record_field_size(struct bpf_insn_access_aux *aux,
u32 size)
struct bpf_prog_ops {
int (*test_run)(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr);
+ int (*test_run_array)(struct bpf_prog_array *progs, const union
bpf_attr *kattr,
+ union bpf_attr __user *uattr);
};
struct bpf_verifier_ops {
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4c24daa43bac..b37a0f39b95f 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -589,7 +589,9 @@ union bpf_attr {
};
struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
- __u32 prog_fd;
+ __u32 prog_fd; /* input: program to test.
mutually exclusive with
+ * prog_fds.
+ */
__u32 retval;
__u32 data_size_in; /* input: len of data_in */
__u32 data_size_out; /* input/output: len of data_out
@@ -609,6 +611,8 @@ union bpf_attr {
__aligned_u64 ctx_out;
__u32 flags;
__u32 cpu;
+ __aligned_u64 prog_fds;
+ __u32 prog_fds_cnt;
} test;
struct { /* anonymous struct used by BPF_*_GET_*_ID */
diff --git a/kernel/bpf/net_namespace.c b/kernel/bpf/net_namespace.c
index 542f275bf252..61e4769f0110 100644
--- a/kernel/bpf/net_namespace.c
+++ b/kernel/bpf/net_namespace.c
@@ -411,7 +411,7 @@ static int netns_bpf_max_progs(enum netns_bpf_attach_type
type)
case NETNS_BPF_FLOW_DISSECTOR:
return 1;
case NETNS_BPF_SK_LOOKUP:
- return 64;
+ return BPF_SK_LOOKUP_MAX_PROGS;
default:
return 0;
}
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c859bc46d06c..f8c7b9d86b3f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3100,13 +3100,17 @@ static int bpf_prog_query(const union bpf_attr *attr,
}
}
-#define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
+#define BPF_PROG_TEST_RUN_LAST_FIELD test.prog_fds_cnt
static int bpf_prog_test_run(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
+ enum bpf_prog_type prog_type = BPF_PROG_TYPE_UNSPEC;
+ u32 prog_fds[BPF_SK_LOOKUP_MAX_PROGS];
+ struct bpf_prog_array *progs = NULL;
struct bpf_prog *prog;
- int ret = -ENOTSUPP;
+ u32 prog_cnt;
+ int i, ret;
if (CHECK_ATTR(BPF_PROG_TEST_RUN))
return -EINVAL;
@@ -3119,14 +3123,67 @@ static int bpf_prog_test_run(const union bpf_attr *attr,
(!attr->test.ctx_size_out && attr->test.ctx_out))
return -EINVAL;
- prog = bpf_prog_get(attr->test.prog_fd);
- if (IS_ERR(prog))
- return PTR_ERR(prog);
+ if ((attr->test.prog_fds && !attr->test.prog_fds_cnt) ||
+ (!attr->test.prog_fds && attr->test.prog_fds_cnt))
+ return -EINVAL;
- if (prog->aux->ops->test_run)
- ret = prog->aux->ops->test_run(prog, attr, uattr);
+ if (attr->test.prog_fds) {
+ u32 __user *uprog_fds = u64_to_user_ptr(attr->test.prog_fds);
- bpf_prog_put(prog);
+ if (attr->test.prog_fds_cnt >= ARRAY_SIZE(prog_fds))
+ return -EINVAL;
+
+ if (attr->test.prog_fd)
+ return -EINVAL;
+
+ prog_cnt = attr->test.prog_fds_cnt;
+ if (copy_from_user(prog_fds, uprog_fds, prog_cnt *
sizeof(prog_fds[0])))
+ return -EFAULT;
+ } else {
+ prog_cnt = 1;
+ prog_fds[0] = attr->test.prog_fd;
+ }
+
+ progs = bpf_prog_array_alloc(prog_cnt, GFP_KERNEL);
+ if (!progs)
+ return -ENOMEM;
+
+ for (i = 0; i < prog_cnt; i++) {
+ prog = bpf_prog_get(prog_fds[i]);
+ if (IS_ERR(prog)) {
+ ret = PTR_ERR(prog);
+ goto out;
+ }
+
+ progs->items[i].prog = prog;
+
+ if (prog_type && prog->type != prog_type) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ prog_type = prog->type;
+ }
+
+ prog = progs->items[0].prog;
+ if (prog->aux->ops->test_run_array) {
+ ret = prog->aux->ops->test_run_array(progs, attr, uattr);
+ } else if (prog->aux->ops->test_run) {
+ if (prog_cnt > 1) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+
+ ret = prog->aux->ops->test_run(progs->items[0].prog, attr,
uattr);
+ } else {
+ ret = -ENOTSUPP;
+ }
+
+out:
+ for (i = 0; i < prog_cnt; i++)
+ if (progs->items[i].prog)
+ bpf_prog_put(progs->items[i].prog);
+ bpf_prog_array_free(progs);
return ret;
}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4c24daa43bac..b37a0f39b95f 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -589,7 +589,9 @@ union bpf_attr {
};
struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
- __u32 prog_fd;
+ __u32 prog_fd; /* input: program to test.
mutually exclusive with
+ * prog_fds.
+ */
__u32 retval;
__u32 data_size_in; /* input: len of data_in */
__u32 data_size_out; /* input/output: len of data_out
@@ -609,6 +611,8 @@ union bpf_attr {
__aligned_u64 ctx_out;
__u32 flags;
__u32 cpu;
+ __aligned_u64 prog_fds;
+ __u32 prog_fds_cnt;
} test;
struct { /* anonymous struct used by BPF_*_GET_*_ID */
--
2.27.0
