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* [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
@ 2020-12-03 21:33 Florent Revest
  2020-12-03 21:33 ` [PATCH bpf-next v2 2/3] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Florent Revest @ 2020-12-03 21:33 UTC (permalink / raw)
  To: bpf; +Cc: ast, daniel, andrii, kpsingh, revest, linux-kernel

This creates a new helper proto because the existing
bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument and only
works for BPF programs where the context is a sock.

This helper could also be useful to other BPF program types such as LSM.

Signed-off-by: Florent Revest <revest@google.com>
---
 include/uapi/linux/bpf.h       | 7 +++++++
 kernel/trace/bpf_trace.c       | 4 ++++
 net/core/filter.c              | 7 +++++++
 tools/include/uapi/linux/bpf.h | 7 +++++++
 4 files changed, 25 insertions(+)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c3458ec1f30a..3e0e33c43998 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1662,6 +1662,13 @@ union bpf_attr {
  * 	Return
  * 		A 8-byte long non-decreasing number.
  *
+ * u64 bpf_get_socket_cookie(void *sk)
+ * 	Description
+ * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
+ * 		*sk*, but gets socket from a BTF **struct sock**.
+ * 	Return
+ * 		A 8-byte long non-decreasing number.
+ *
  * u32 bpf_get_socket_uid(struct sk_buff *skb)
  * 	Return
  * 		The owner UID of the socket associated to *skb*. If the socket
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d255bc9b2bfa..14ad96579813 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1725,6 +1725,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	}
 }
 
+extern const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto;
+
 const struct bpf_func_proto *
 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -1748,6 +1750,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sk_storage_get_tracing_proto;
 	case BPF_FUNC_sk_storage_delete:
 		return &bpf_sk_storage_delete_tracing_proto;
+	case BPF_FUNC_get_socket_cookie:
+		return &bpf_get_socket_cookie_sock_tracing_proto;
 #endif
 	case BPF_FUNC_seq_printf:
 		return prog->expected_attach_type == BPF_TRACE_ITER ?
diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..177c4e5e529d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4631,6 +4631,13 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 };
 
+const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto = {
+	.func		= bpf_get_socket_cookie_sock,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+};
+
 BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx)
 {
 	return __sock_gen_cookie(ctx->sk);
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index c3458ec1f30a..3e0e33c43998 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1662,6 +1662,13 @@ union bpf_attr {
  * 	Return
  * 		A 8-byte long non-decreasing number.
  *
+ * u64 bpf_get_socket_cookie(void *sk)
+ * 	Description
+ * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
+ * 		*sk*, but gets socket from a BTF **struct sock**.
+ * 	Return
+ * 		A 8-byte long non-decreasing number.
+ *
  * u32 bpf_get_socket_uid(struct sk_buff *skb)
  * 	Return
  * 		The owner UID of the socket associated to *skb*. If the socket
-- 
2.29.2.576.ga3fc446d84-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH bpf-next v2 2/3] selftests/bpf: Integrate the socket_cookie test to test_progs
  2020-12-03 21:33 [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
@ 2020-12-03 21:33 ` Florent Revest
  2020-12-03 21:33 ` [PATCH bpf-next v2 3/3] bpf: Add a selftest for the tracing bpf_get_socket_cookie Florent Revest
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 9+ messages in thread
From: Florent Revest @ 2020-12-03 21:33 UTC (permalink / raw)
  To: bpf; +Cc: ast, daniel, andrii, kpsingh, revest, linux-kernel

Currently, the selftest for the BPF socket_cookie helpers is built and
run independently from test_progs. It's easy to forget and hard to
maintain.

This patch moves the socket cookies test into prog_tests/ and vastly
simplifies its logic by:
- rewriting the loading code with BPF skeletons
- rewriting the server/client code with network helpers
- rewriting the cgroup code with test__join_cgroup
- rewriting the error handling code with CHECKs

Signed-off-by: Florent Revest <revest@google.com>
---
 tools/testing/selftests/bpf/Makefile          |   3 +-
 .../selftests/bpf/prog_tests/socket_cookie.c  |  82 +++++++
 .../selftests/bpf/progs/socket_cookie_prog.c  |   2 -
 .../selftests/bpf/test_socket_cookie.c        | 208 ------------------
 4 files changed, 83 insertions(+), 212 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/socket_cookie.c
 delete mode 100644 tools/testing/selftests/bpf/test_socket_cookie.c

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 894192c319fb..8c7ff88f0eb3 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -33,7 +33,7 @@ LDLIBS += -lcap -lelf -lz -lrt -lpthread
 # Order correspond to 'make run_tests' order
 TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
 	test_verifier_log test_dev_cgroup \
-	test_sock test_sockmap get_cgroup_id_user test_socket_cookie \
+	test_sock test_sockmap get_cgroup_id_user \
 	test_cgroup_storage \
 	test_netcnt test_tcpnotify_user test_sysctl \
 	test_progs-no_alu32 \
@@ -161,7 +161,6 @@ $(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
 $(OUTPUT)/test_skb_cgroup_id_user: cgroup_helpers.c
 $(OUTPUT)/test_sock: cgroup_helpers.c
 $(OUTPUT)/test_sock_addr: cgroup_helpers.c
-$(OUTPUT)/test_socket_cookie: cgroup_helpers.c
 $(OUTPUT)/test_sockmap: cgroup_helpers.c
 $(OUTPUT)/test_tcpnotify_user: cgroup_helpers.c trace_helpers.c
 $(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
diff --git a/tools/testing/selftests/bpf/prog_tests/socket_cookie.c b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c
new file mode 100644
index 000000000000..53d0c44e7907
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Google LLC.
+// Copyright (c) 2018 Facebook
+
+#include <test_progs.h>
+#include "socket_cookie_prog.skel.h"
+#include "network_helpers.h"
+
+static int duration;
+
+struct socket_cookie {
+	__u64 cookie_key;
+	__u32 cookie_value;
+};
+
+void test_socket_cookie(void)
+{
+	socklen_t addr_len = sizeof(struct sockaddr_in6);
+	struct bpf_link *set_link, *update_link;
+	int server_fd, client_fd, cgroup_fd;
+	struct socket_cookie_prog *skel;
+	__u32 cookie_expected_value;
+	struct sockaddr_in6 addr;
+	struct socket_cookie val;
+	int err = 0;
+
+	skel = socket_cookie_prog__open_and_load();
+	if (CHECK(!skel, "socket_cookie_prog__open_and_load",
+		  "skeleton open_and_load failed\n"))
+		return;
+
+	cgroup_fd = test__join_cgroup("/socket_cookie");
+	if (CHECK(cgroup_fd < 0, "join_cgroup", "cgroup creation failed\n"))
+		goto destroy_skel;
+
+	set_link = bpf_program__attach_cgroup(skel->progs.set_cookie,
+					      cgroup_fd);
+	if (CHECK(IS_ERR(set_link), "set-link-cg-attach", "err %ld\n",
+		  PTR_ERR(set_link)))
+		goto close_cgroup_fd;
+
+	update_link = bpf_program__attach_cgroup(skel->progs.update_cookie,
+						 cgroup_fd);
+	if (CHECK(IS_ERR(update_link), "update-link-cg-attach", "err %ld\n",
+		  PTR_ERR(update_link)))
+		goto free_set_link;
+
+	server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+	if (CHECK(server_fd < 0, "start_server", "errno %d\n", errno))
+		goto free_update_link;
+
+	client_fd = connect_to_fd(server_fd, 0);
+	if (CHECK(client_fd < 0, "connect_to_fd", "errno %d\n", errno))
+		goto close_server_fd;
+
+	err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.socket_cookies),
+				  &client_fd, &val);
+	if (CHECK(err, "map_lookup", "err %d errno %d\n", err, errno))
+		goto close_client_fd;
+
+	err = getsockname(client_fd, (struct sockaddr *)&addr, &addr_len);
+	if (CHECK(err, "getsockname", "Can't get client local addr\n"))
+		goto close_client_fd;
+
+	cookie_expected_value = (ntohs(addr.sin6_port) << 8) | 0xFF;
+	CHECK(val.cookie_value != cookie_expected_value, "",
+	      "Unexpected value in map: %x != %x\n", val.cookie_value,
+	      cookie_expected_value);
+
+close_client_fd:
+	close(client_fd);
+close_server_fd:
+	close(server_fd);
+free_update_link:
+	bpf_link__destroy(update_link);
+free_set_link:
+	bpf_link__destroy(set_link);
+close_cgroup_fd:
+	close(cgroup_fd);
+destroy_skel:
+	socket_cookie_prog__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
index 0cb5656a22b0..81e84be6f86d 100644
--- a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
+++ b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
@@ -65,6 +65,4 @@ int update_cookie(struct bpf_sock_ops *ctx)
 	return 1;
 }
 
-int _version SEC("version") = 1;
-
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_socket_cookie.c b/tools/testing/selftests/bpf/test_socket_cookie.c
deleted file mode 100644
index ca7ca87e91aa..000000000000
--- a/tools/testing/selftests/bpf/test_socket_cookie.c
+++ /dev/null
@@ -1,208 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (c) 2018 Facebook
-
-#include <string.h>
-#include <unistd.h>
-
-#include <arpa/inet.h>
-#include <netinet/in.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-
-#include <bpf/bpf.h>
-#include <bpf/libbpf.h>
-
-#include "bpf_rlimit.h"
-#include "cgroup_helpers.h"
-
-#define CG_PATH			"/foo"
-#define SOCKET_COOKIE_PROG	"./socket_cookie_prog.o"
-
-struct socket_cookie {
-	__u64 cookie_key;
-	__u32 cookie_value;
-};
-
-static int start_server(void)
-{
-	struct sockaddr_in6 addr;
-	int fd;
-
-	fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (fd == -1) {
-		log_err("Failed to create server socket");
-		goto out;
-	}
-
-	memset(&addr, 0, sizeof(addr));
-	addr.sin6_family = AF_INET6;
-	addr.sin6_addr = in6addr_loopback;
-	addr.sin6_port = 0;
-
-	if (bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) == -1) {
-		log_err("Failed to bind server socket");
-		goto close_out;
-	}
-
-	if (listen(fd, 128) == -1) {
-		log_err("Failed to listen on server socket");
-		goto close_out;
-	}
-
-	goto out;
-
-close_out:
-	close(fd);
-	fd = -1;
-out:
-	return fd;
-}
-
-static int connect_to_server(int server_fd)
-{
-	struct sockaddr_storage addr;
-	socklen_t len = sizeof(addr);
-	int fd;
-
-	fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (fd == -1) {
-		log_err("Failed to create client socket");
-		goto out;
-	}
-
-	if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
-		log_err("Failed to get server addr");
-		goto close_out;
-	}
-
-	if (connect(fd, (const struct sockaddr *)&addr, len) == -1) {
-		log_err("Fail to connect to server");
-		goto close_out;
-	}
-
-	goto out;
-
-close_out:
-	close(fd);
-	fd = -1;
-out:
-	return fd;
-}
-
-static int validate_map(struct bpf_map *map, int client_fd)
-{
-	__u32 cookie_expected_value;
-	struct sockaddr_in6 addr;
-	socklen_t len = sizeof(addr);
-	struct socket_cookie val;
-	int err = 0;
-	int map_fd;
-
-	if (!map) {
-		log_err("Map not found in BPF object");
-		goto err;
-	}
-
-	map_fd = bpf_map__fd(map);
-
-	err = bpf_map_lookup_elem(map_fd, &client_fd, &val);
-
-	err = getsockname(client_fd, (struct sockaddr *)&addr, &len);
-	if (err) {
-		log_err("Can't get client local addr");
-		goto out;
-	}
-
-	cookie_expected_value = (ntohs(addr.sin6_port) << 8) | 0xFF;
-	if (val.cookie_value != cookie_expected_value) {
-		log_err("Unexpected value in map: %x != %x", val.cookie_value,
-			cookie_expected_value);
-		goto err;
-	}
-
-	goto out;
-err:
-	err = -1;
-out:
-	return err;
-}
-
-static int run_test(int cgfd)
-{
-	enum bpf_attach_type attach_type;
-	struct bpf_prog_load_attr attr;
-	struct bpf_program *prog;
-	struct bpf_object *pobj;
-	const char *prog_name;
-	int server_fd = -1;
-	int client_fd = -1;
-	int prog_fd = -1;
-	int err = 0;
-
-	memset(&attr, 0, sizeof(attr));
-	attr.file = SOCKET_COOKIE_PROG;
-	attr.prog_type = BPF_PROG_TYPE_UNSPEC;
-	attr.prog_flags = BPF_F_TEST_RND_HI32;
-
-	err = bpf_prog_load_xattr(&attr, &pobj, &prog_fd);
-	if (err) {
-		log_err("Failed to load %s", attr.file);
-		goto out;
-	}
-
-	bpf_object__for_each_program(prog, pobj) {
-		prog_name = bpf_program__section_name(prog);
-
-		if (libbpf_attach_type_by_name(prog_name, &attach_type))
-			goto err;
-
-		err = bpf_prog_attach(bpf_program__fd(prog), cgfd, attach_type,
-				      BPF_F_ALLOW_OVERRIDE);
-		if (err) {
-			log_err("Failed to attach prog %s", prog_name);
-			goto out;
-		}
-	}
-
-	server_fd = start_server();
-	if (server_fd == -1)
-		goto err;
-
-	client_fd = connect_to_server(server_fd);
-	if (client_fd == -1)
-		goto err;
-
-	if (validate_map(bpf_map__next(NULL, pobj), client_fd))
-		goto err;
-
-	goto out;
-err:
-	err = -1;
-out:
-	close(client_fd);
-	close(server_fd);
-	bpf_object__close(pobj);
-	printf("%s\n", err ? "FAILED" : "PASSED");
-	return err;
-}
-
-int main(int argc, char **argv)
-{
-	int cgfd = -1;
-	int err = 0;
-
-	cgfd = cgroup_setup_and_join(CG_PATH);
-	if (cgfd < 0)
-		goto err;
-
-	if (run_test(cgfd))
-		goto err;
-
-	goto out;
-err:
-	err = -1;
-out:
-	close(cgfd);
-	cleanup_cgroup_environment();
-	return err;
-}
-- 
2.29.2.576.ga3fc446d84-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH bpf-next v2 3/3] bpf: Add a selftest for the tracing bpf_get_socket_cookie
  2020-12-03 21:33 [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
  2020-12-03 21:33 ` [PATCH bpf-next v2 2/3] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
@ 2020-12-03 21:33 ` Florent Revest
  2020-12-04 18:56 ` [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Daniel Borkmann
  2020-12-04 19:47 ` Martin KaFai Lau
  3 siblings, 0 replies; 9+ messages in thread
From: Florent Revest @ 2020-12-03 21:33 UTC (permalink / raw)
  To: bpf; +Cc: ast, daniel, andrii, kpsingh, revest, linux-kernel

This builds up on the existing socket cookie test which checks whether
the bpf_get_socket_cookie helpers provide the same value in
cgroup/connect6 and sockops programs for a socket created by the
userspace part of the test.

Adding a tracing program to the existing objects requires a different
attachment strategy and different headers.

Signed-off-by: Florent Revest <revest@google.com>
---
 .../selftests/bpf/prog_tests/socket_cookie.c  | 24 +++++++----
 .../selftests/bpf/progs/socket_cookie_prog.c  | 41 ++++++++++++++++---
 2 files changed, 52 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/socket_cookie.c b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c
index 53d0c44e7907..e5c5e2ea1deb 100644
--- a/tools/testing/selftests/bpf/prog_tests/socket_cookie.c
+++ b/tools/testing/selftests/bpf/prog_tests/socket_cookie.c
@@ -15,8 +15,8 @@ struct socket_cookie {
 
 void test_socket_cookie(void)
 {
+	struct bpf_link *set_link, *update_sockops_link, *update_tracing_link;
 	socklen_t addr_len = sizeof(struct sockaddr_in6);
-	struct bpf_link *set_link, *update_link;
 	int server_fd, client_fd, cgroup_fd;
 	struct socket_cookie_prog *skel;
 	__u32 cookie_expected_value;
@@ -39,15 +39,21 @@ void test_socket_cookie(void)
 		  PTR_ERR(set_link)))
 		goto close_cgroup_fd;
 
-	update_link = bpf_program__attach_cgroup(skel->progs.update_cookie,
-						 cgroup_fd);
-	if (CHECK(IS_ERR(update_link), "update-link-cg-attach", "err %ld\n",
-		  PTR_ERR(update_link)))
+	update_sockops_link = bpf_program__attach_cgroup(
+		skel->progs.update_cookie_sockops, cgroup_fd);
+	if (CHECK(IS_ERR(update_sockops_link), "update-sockops-link-cg-attach",
+		  "err %ld\n", PTR_ERR(update_sockops_link)))
 		goto free_set_link;
 
+	update_tracing_link = bpf_program__attach(
+		skel->progs.update_cookie_tracing);
+	if (CHECK(IS_ERR(update_tracing_link), "update-tracing-link-attach",
+		  "err %ld\n", PTR_ERR(update_tracing_link)))
+		goto free_update_sockops_link;
+
 	server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
 	if (CHECK(server_fd < 0, "start_server", "errno %d\n", errno))
-		goto free_update_link;
+		goto free_update_tracing_link;
 
 	client_fd = connect_to_fd(server_fd, 0);
 	if (CHECK(client_fd < 0, "connect_to_fd", "errno %d\n", errno))
@@ -71,8 +77,10 @@ void test_socket_cookie(void)
 	close(client_fd);
 close_server_fd:
 	close(server_fd);
-free_update_link:
-	bpf_link__destroy(update_link);
+free_update_tracing_link:
+	bpf_link__destroy(update_tracing_link);
+free_update_sockops_link:
+	bpf_link__destroy(update_sockops_link);
 free_set_link:
 	bpf_link__destroy(set_link);
 close_cgroup_fd:
diff --git a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
index 81e84be6f86d..1f770b732cb1 100644
--- a/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
+++ b/tools/testing/selftests/bpf/progs/socket_cookie_prog.c
@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2018 Facebook
 
-#include <linux/bpf.h>
-#include <sys/socket.h>
+#include "vmlinux.h"
 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
+#include <bpf/bpf_tracing.h>
+
+#define AF_INET6 10
 
 struct socket_cookie {
 	__u64 cookie_key;
@@ -19,6 +21,14 @@ struct {
 	__type(value, struct socket_cookie);
 } socket_cookies SEC(".maps");
 
+/*
+ * These three programs get executed in a row on connect() syscalls. The
+ * userspace side of the test creates a client socket, issues a connect() on it
+ * and then checks that the local storage associated with this socket has:
+ * cookie_value == local_port << 8 | 0xFF
+ * The different parts of this cookie_value are appended by those hooks if they
+ * all agree on the output of bpf_get_socket_cookie().
+ */
 SEC("cgroup/connect6")
 int set_cookie(struct bpf_sock_addr *ctx)
 {
@@ -32,14 +42,14 @@ int set_cookie(struct bpf_sock_addr *ctx)
 	if (!p)
 		return 1;
 
-	p->cookie_value = 0xFF;
+	p->cookie_value = 0xF;
 	p->cookie_key = bpf_get_socket_cookie(ctx);
 
 	return 1;
 }
 
 SEC("sockops")
-int update_cookie(struct bpf_sock_ops *ctx)
+int update_cookie_sockops(struct bpf_sock_ops *ctx)
 {
 	struct bpf_sock *sk;
 	struct socket_cookie *p;
@@ -60,9 +70,30 @@ int update_cookie(struct bpf_sock_ops *ctx)
 	if (p->cookie_key != bpf_get_socket_cookie(ctx))
 		return 1;
 
-	p->cookie_value = (ctx->local_port << 8) | p->cookie_value;
+	p->cookie_value |= (ctx->local_port << 8);
 
 	return 1;
 }
 
+SEC("fexit/inet_stream_connect")
+int BPF_PROG(update_cookie_tracing, struct socket *sock,
+	     struct sockaddr *uaddr, int addr_len, int flags)
+{
+	struct socket_cookie *p;
+
+	if (uaddr->sa_family != AF_INET6)
+		return 0;
+
+	p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0);
+	if (!p)
+		return 0;
+
+	if (p->cookie_key != bpf_get_socket_cookie(sock->sk))
+		return 0;
+
+	p->cookie_value |= 0xF0;
+
+	return 0;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.29.2.576.ga3fc446d84-goog


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-03 21:33 [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
  2020-12-03 21:33 ` [PATCH bpf-next v2 2/3] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
  2020-12-03 21:33 ` [PATCH bpf-next v2 3/3] bpf: Add a selftest for the tracing bpf_get_socket_cookie Florent Revest
@ 2020-12-04 18:56 ` Daniel Borkmann
  2020-12-04 19:03   ` Daniel Borkmann
  2020-12-04 19:47 ` Martin KaFai Lau
  3 siblings, 1 reply; 9+ messages in thread
From: Daniel Borkmann @ 2020-12-04 18:56 UTC (permalink / raw)
  To: Florent Revest, bpf; +Cc: ast, andrii, kpsingh, revest, linux-kernel

On 12/3/20 10:33 PM, Florent Revest wrote:
> This creates a new helper proto because the existing
> bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument and only
> works for BPF programs where the context is a sock.
> 
> This helper could also be useful to other BPF program types such as LSM.
> 
> Signed-off-by: Florent Revest <revest@google.com>
> ---
>   include/uapi/linux/bpf.h       | 7 +++++++
>   kernel/trace/bpf_trace.c       | 4 ++++
>   net/core/filter.c              | 7 +++++++
>   tools/include/uapi/linux/bpf.h | 7 +++++++
>   4 files changed, 25 insertions(+)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index c3458ec1f30a..3e0e33c43998 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1662,6 +1662,13 @@ union bpf_attr {
>    * 	Return
>    * 		A 8-byte long non-decreasing number.
>    *
> + * u64 bpf_get_socket_cookie(void *sk)
> + * 	Description
> + * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
> + * 		*sk*, but gets socket from a BTF **struct sock**.
> + * 	Return
> + * 		A 8-byte long non-decreasing number.

I would not mention this here since it's not fully correct and we should avoid users
taking non-decreasing granted in their progs. The only assumption you can make is
that it can be considered a unique number. See also [0] with reverse counter..

   [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92acdc58ab11af66fcaef485433fde61b5e32fac

> + *
>    * u32 bpf_get_socket_uid(struct sk_buff *skb)
>    * 	Return
>    * 		The owner UID of the socket associated to *skb*. If the socket
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index d255bc9b2bfa..14ad96579813 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1725,6 +1725,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>   	}
>   }
>   
> +extern const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto;
> +
>   const struct bpf_func_proto *
>   tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>   {
> @@ -1748,6 +1750,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>   		return &bpf_sk_storage_get_tracing_proto;
>   	case BPF_FUNC_sk_storage_delete:
>   		return &bpf_sk_storage_delete_tracing_proto;
> +	case BPF_FUNC_get_socket_cookie:
> +		return &bpf_get_socket_cookie_sock_tracing_proto;
>   #endif
>   	case BPF_FUNC_seq_printf:
>   		return prog->expected_attach_type == BPF_TRACE_ITER ?
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 2ca5eecebacf..177c4e5e529d 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4631,6 +4631,13 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = {
>   	.arg1_type	= ARG_PTR_TO_CTX,
>   };
>   
> +const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto = {
> +	.func		= bpf_get_socket_cookie_sock,
> +	.gpl_only	= false,
> +	.ret_type	= RET_INTEGER,
> +	.arg1_type      = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
> +};
> +

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-04 18:56 ` [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Daniel Borkmann
@ 2020-12-04 19:03   ` Daniel Borkmann
  2020-12-08 19:30     ` Florent Revest
  0 siblings, 1 reply; 9+ messages in thread
From: Daniel Borkmann @ 2020-12-04 19:03 UTC (permalink / raw)
  To: Florent Revest, bpf; +Cc: ast, andrii, kpsingh, revest, linux-kernel

On 12/4/20 7:56 PM, Daniel Borkmann wrote:
> On 12/3/20 10:33 PM, Florent Revest wrote:
>> This creates a new helper proto because the existing
>> bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument and only
>> works for BPF programs where the context is a sock.
>>
>> This helper could also be useful to other BPF program types such as LSM.
>>
>> Signed-off-by: Florent Revest <revest@google.com>
>> ---
>>   include/uapi/linux/bpf.h       | 7 +++++++
>>   kernel/trace/bpf_trace.c       | 4 ++++
>>   net/core/filter.c              | 7 +++++++
>>   tools/include/uapi/linux/bpf.h | 7 +++++++
>>   4 files changed, 25 insertions(+)
>>
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index c3458ec1f30a..3e0e33c43998 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -1662,6 +1662,13 @@ union bpf_attr {
>>    *     Return
>>    *         A 8-byte long non-decreasing number.
>>    *
>> + * u64 bpf_get_socket_cookie(void *sk)
>> + *     Description
>> + *         Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
>> + *         *sk*, but gets socket from a BTF **struct sock**.
>> + *     Return
>> + *         A 8-byte long non-decreasing number.
> 
> I would not mention this here since it's not fully correct and we should avoid users
> taking non-decreasing granted in their progs. The only assumption you can make is
> that it can be considered a unique number. See also [0] with reverse counter..
> 
>    [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92acdc58ab11af66fcaef485433fde61b5e32fac

One more thought, in case you plan to use this from sleepable context, you would
need to use sock_gen_cookie() variant in the BPF helper instead.

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-03 21:33 [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
                   ` (2 preceding siblings ...)
  2020-12-04 18:56 ` [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Daniel Borkmann
@ 2020-12-04 19:47 ` Martin KaFai Lau
  2020-12-08 19:40   ` Florent Revest
  3 siblings, 1 reply; 9+ messages in thread
From: Martin KaFai Lau @ 2020-12-04 19:47 UTC (permalink / raw)
  To: Florent Revest; +Cc: bpf, ast, daniel, andrii, kpsingh, revest, linux-kernel

On Thu, Dec 03, 2020 at 10:33:28PM +0100, Florent Revest wrote:
> This creates a new helper proto because the existing
> bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument and only
> works for BPF programs where the context is a sock.
> 
> This helper could also be useful to other BPF program types such as LSM.
> 
> Signed-off-by: Florent Revest <revest@google.com>
> ---
>  include/uapi/linux/bpf.h       | 7 +++++++
>  kernel/trace/bpf_trace.c       | 4 ++++
>  net/core/filter.c              | 7 +++++++
>  tools/include/uapi/linux/bpf.h | 7 +++++++
>  4 files changed, 25 insertions(+)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index c3458ec1f30a..3e0e33c43998 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1662,6 +1662,13 @@ union bpf_attr {
>   * 	Return
>   * 		A 8-byte long non-decreasing number.
>   *
> + * u64 bpf_get_socket_cookie(void *sk)
> + * 	Description
> + * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
> + * 		*sk*, but gets socket from a BTF **struct sock**.
> + * 	Return
> + * 		A 8-byte long non-decreasing number.
> + *
>   * u32 bpf_get_socket_uid(struct sk_buff *skb)
>   * 	Return
>   * 		The owner UID of the socket associated to *skb*. If the socket
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index d255bc9b2bfa..14ad96579813 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1725,6 +1725,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  	}
>  }
>  
> +extern const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto;
> +
>  const struct bpf_func_proto *
>  tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  {
> @@ -1748,6 +1750,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  		return &bpf_sk_storage_get_tracing_proto;
>  	case BPF_FUNC_sk_storage_delete:
>  		return &bpf_sk_storage_delete_tracing_proto;
> +	case BPF_FUNC_get_socket_cookie:
> +		return &bpf_get_socket_cookie_sock_tracing_proto;
>  #endif
>  	case BPF_FUNC_seq_printf:
>  		return prog->expected_attach_type == BPF_TRACE_ITER ?
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 2ca5eecebacf..177c4e5e529d 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4631,6 +4631,13 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = {
>  	.arg1_type	= ARG_PTR_TO_CTX,
>  };
>  
> +const struct bpf_func_proto bpf_get_socket_cookie_sock_tracing_proto = {
> +	.func		= bpf_get_socket_cookie_sock,
> +	.gpl_only	= false,
> +	.ret_type	= RET_INTEGER,
> +	.arg1_type      = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
In tracing where it gets a sk pointer, the sk could be NULL.
A NULL check is required in the helper. Please refer to
bpf_skc_to_tcp_sock[_proto] as an example.

This proto is in general also useful for non tracing context where
it can get a hold of a sk pointer. (e.g. another similar usage that will
have a hold on a sk pointer for BPF_PROG_TYPE_SK_REUSEPORT [0]).
In case if you don't need sleepable at this point as Daniel
mentioned in another thread.  Does it make sense to rename this
proto to something like bpf_get_socket_pointer_cookie_proto?

[0]: https://lore.kernel.org/bpf/20201201144418.35045-10-kuniyu@amazon.co.jp/

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-04 19:03   ` Daniel Borkmann
@ 2020-12-08 19:30     ` Florent Revest
  2020-12-09  8:29       ` Daniel Borkmann
  0 siblings, 1 reply; 9+ messages in thread
From: Florent Revest @ 2020-12-08 19:30 UTC (permalink / raw)
  To: Daniel Borkmann, bpf; +Cc: ast, andrii, kpsingh, revest, linux-kernel

On Fri, 2020-12-04 at 20:03 +0100, Daniel Borkmann wrote:
> On 12/4/20 7:56 PM, Daniel Borkmann wrote:
> > On 12/3/20 10:33 PM, Florent Revest wrote:
> > > This creates a new helper proto because the existing
> > > bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument
> > > and only
> > > works for BPF programs where the context is a sock.
> > > 
> > > This helper could also be useful to other BPF program types such
> > > as LSM.
> > > 
> > > Signed-off-by: Florent Revest <revest@google.com>
> > > ---
> > >   include/uapi/linux/bpf.h       | 7 +++++++
> > >   kernel/trace/bpf_trace.c       | 4 ++++
> > >   net/core/filter.c              | 7 +++++++
> > >   tools/include/uapi/linux/bpf.h | 7 +++++++
> > >   4 files changed, 25 insertions(+)
> > > 
> > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > > index c3458ec1f30a..3e0e33c43998 100644
> > > --- a/include/uapi/linux/bpf.h
> > > +++ b/include/uapi/linux/bpf.h
> > > @@ -1662,6 +1662,13 @@ union bpf_attr {
> > >    *     Return
> > >    *         A 8-byte long non-decreasing number.
> > >    *
> > > + * u64 bpf_get_socket_cookie(void *sk)
> > > + *     Description
> > > + *         Equivalent to **bpf_get_socket_cookie**\ () helper
> > > that accepts
> > > + *         *sk*, but gets socket from a BTF **struct sock**.
> > > + *     Return
> > > + *         A 8-byte long non-decreasing number.
> > 
> > I would not mention this here since it's not fully correct and we
> > should avoid users taking non-decreasing granted in their progs.
> > The only assumption you can make is that it can be considered a
> > unique number. See also [0] with reverse counter..
> > 
> >    [0] 
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92acdc58ab11af66fcaef485433fde61b5e32fac

Ah this is a good point, thank you! I will send a v3 with an extra
patch that s/non-decreasing/unique/ in the other descriptions. I had
not given it any extra thought, I just stupidly copied/pasted existing
descriptions. :) 

> One more thought, in case you plan to use this from sleepable
> context, you would need to use sock_gen_cookie() variant in the BPF
> helper instead.

Out of curiosity, why don't we just always call sock_gen_cookie? Is it
to avoid the performance impact of increasing the preempt counter and
introducing a memory barriers ?


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-04 19:47 ` Martin KaFai Lau
@ 2020-12-08 19:40   ` Florent Revest
  0 siblings, 0 replies; 9+ messages in thread
From: Florent Revest @ 2020-12-08 19:40 UTC (permalink / raw)
  To: Martin KaFai Lau; +Cc: bpf, ast, daniel, andrii, kpsingh, revest, linux-kernel

On Fri, 2020-12-04 at 11:47 -0800, Martin KaFai Lau wrote:
> On Thu, Dec 03, 2020 at 10:33:28PM +0100, Florent Revest wrote:
> > +const struct bpf_func_proto
> > bpf_get_socket_cookie_sock_tracing_proto = {
> > +	.func		= bpf_get_socket_cookie_sock,
> > +	.gpl_only	= false,
> > +	.ret_type	= RET_INTEGER,
> > +	.arg1_type      = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
> 
> In tracing where it gets a sk pointer, the sk could be NULL.
> A NULL check is required in the helper. Please refer to
> bpf_skc_to_tcp_sock[_proto] as an example.

Ah, good catch! :) 

> This proto is in general also useful for non tracing context where
> it can get a hold of a sk pointer. (e.g. another similar usage that
> will have a hold on a sk pointer for BPF_PROG_TYPE_SK_REUSEPORT [0]).

Agreed.

> In case if you don't need sleepable at this point as Daniel
> mentioned in another thread.  Does it make sense to rename this
> proto to something like bpf_get_socket_pointer_cookie_proto?

My understanding is that I could have two helpers definitions and
protos, one calling sock_gen_cookie and the other one calling
__sock_gen_cookie. Then I could just use:

return prog->aux->sleepable
       ? bpf_get_socket_pointer_cookie_sleepable_proto
       : bpf_get_socket_pointer_cookie_proto;

Would that work ?


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs
  2020-12-08 19:30     ` Florent Revest
@ 2020-12-09  8:29       ` Daniel Borkmann
  0 siblings, 0 replies; 9+ messages in thread
From: Daniel Borkmann @ 2020-12-09  8:29 UTC (permalink / raw)
  To: Florent Revest, bpf; +Cc: ast, andrii, kpsingh, revest, linux-kernel

On 12/8/20 8:30 PM, Florent Revest wrote:
> On Fri, 2020-12-04 at 20:03 +0100, Daniel Borkmann wrote:
>> On 12/4/20 7:56 PM, Daniel Borkmann wrote:
>>> On 12/3/20 10:33 PM, Florent Revest wrote:
>>>> This creates a new helper proto because the existing
>>>> bpf_get_socket_cookie_sock_proto has a ARG_PTR_TO_CTX argument
>>>> and only
>>>> works for BPF programs where the context is a sock.
>>>>
>>>> This helper could also be useful to other BPF program types such
>>>> as LSM.
>>>>
>>>> Signed-off-by: Florent Revest <revest@google.com>
>>>> ---
>>>>    include/uapi/linux/bpf.h       | 7 +++++++
>>>>    kernel/trace/bpf_trace.c       | 4 ++++
>>>>    net/core/filter.c              | 7 +++++++
>>>>    tools/include/uapi/linux/bpf.h | 7 +++++++
>>>>    4 files changed, 25 insertions(+)
>>>>
>>>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>>>> index c3458ec1f30a..3e0e33c43998 100644
>>>> --- a/include/uapi/linux/bpf.h
>>>> +++ b/include/uapi/linux/bpf.h
>>>> @@ -1662,6 +1662,13 @@ union bpf_attr {
>>>>     *     Return
>>>>     *         A 8-byte long non-decreasing number.
>>>>     *
>>>> + * u64 bpf_get_socket_cookie(void *sk)
>>>> + *     Description
>>>> + *         Equivalent to **bpf_get_socket_cookie**\ () helper
>>>> that accepts
>>>> + *         *sk*, but gets socket from a BTF **struct sock**.
>>>> + *     Return
>>>> + *         A 8-byte long non-decreasing number.
>>>
>>> I would not mention this here since it's not fully correct and we
>>> should avoid users taking non-decreasing granted in their progs.
>>> The only assumption you can make is that it can be considered a
>>> unique number. See also [0] with reverse counter..
>>>
>>>     [0]
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=92acdc58ab11af66fcaef485433fde61b5e32fac
> 
> Ah this is a good point, thank you! I will send a v3 with an extra
> patch that s/non-decreasing/unique/ in the other descriptions. I had
> not given it any extra thought, I just stupidly copied/pasted existing
> descriptions. :)
> 
>> One more thought, in case you plan to use this from sleepable
>> context, you would need to use sock_gen_cookie() variant in the BPF
>> helper instead.
> 
> Out of curiosity, why don't we just always call sock_gen_cookie? Is it
> to avoid the performance impact of increasing the preempt counter and
> introducing a memory barriers ?

Yes, all the other contexts where the existing helpers are used already have
preemption disabled, so the extra preempt_{disable,enable}() is unnecessary
overhead given we want the cookie generation be efficient.

Thanks,
Daniel

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2020-12-09  8:29 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-03 21:33 [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
2020-12-03 21:33 ` [PATCH bpf-next v2 2/3] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
2020-12-03 21:33 ` [PATCH bpf-next v2 3/3] bpf: Add a selftest for the tracing bpf_get_socket_cookie Florent Revest
2020-12-04 18:56 ` [PATCH bpf-next v2 1/3] bpf: Expose bpf_get_socket_cookie to tracing programs Daniel Borkmann
2020-12-04 19:03   ` Daniel Borkmann
2020-12-08 19:30     ` Florent Revest
2020-12-09  8:29       ` Daniel Borkmann
2020-12-04 19:47 ` Martin KaFai Lau
2020-12-08 19:40   ` Florent Revest

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