[PATCH bpf-next,v6 0/4] xfrm: interface: Add unstable helpers for XFRM metadata

[PATCH bpf-next,v6 0/4] xfrm: interface: Add unstable helpers for XFRM metadata

[Eyal Birger]

This patch series adds xfrm metadata helpers using the unstable kfunc
call interface for the TC-BPF hooks.

This allows steering traffic towards different IPsec connections based
on logic implemented in bpf programs.

The helpers are integrated into the xfrm_interface module. For this
purpose the main functionality of this module is moved to
xfrm_interface_core.c.

---

changes in v6: fix sparse warning in patch 2
changes in v5:
  - avoid cleanup of percpu dsts as detailed in patch 2
changes in v3:
  - tag bpf-next tree instead of ipsec-next
  - add IFLA_XFRM_COLLECT_METADATA sync patch

Eyal Birger (4):
  xfrm: interface: rename xfrm_interface.c to xfrm_interface_core.c
  xfrm: interface: Add unstable helpers for setting/getting XFRM
    metadata from TC-BPF
  tools: add IFLA_XFRM_COLLECT_METADATA to uapi/linux/if_link.h
  selftests/bpf: add xfrm_info tests

 include/net/dst_metadata.h                    |   1 +
 include/net/xfrm.h                            |  17 +
 net/core/dst.c                                |   8 +-
 net/core/filter.c                             |   9 +
 net/xfrm/Makefile                             |   8 +
 net/xfrm/xfrm_interface_bpf.c                 | 115 ++++++
 ...xfrm_interface.c => xfrm_interface_core.c} |  14 +
 tools/include/uapi/linux/if_link.h            |   1 +
 tools/testing/selftests/bpf/DENYLIST.s390x    |   1 +
 tools/testing/selftests/bpf/config            |   2 +
 .../selftests/bpf/prog_tests/xfrm_info.c      | 365 ++++++++++++++++++
 .../selftests/bpf/progs/bpf_tracing_net.h     |   3 +
 tools/testing/selftests/bpf/progs/xfrm_info.c |  35 ++
 13 files changed, 577 insertions(+), 2 deletions(-)
 create mode 100644 net/xfrm/xfrm_interface_bpf.c
 rename net/xfrm/{xfrm_interface.c => xfrm_interface_core.c} (98%)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xfrm_info.c
 create mode 100644 tools/testing/selftests/bpf/progs/xfrm_info.c

-- 
2.34.1

[PATCH bpf-next,v6 1/4] xfrm: interface: rename xfrm_interface.c to xfrm_interface_core.c

[Eyal Birger]

This change allows adding additional files to the xfrm_interface module.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
---
 net/xfrm/Makefile                                    | 2 ++
 net/xfrm/{xfrm_interface.c => xfrm_interface_core.c} | 0
 2 files changed, 2 insertions(+)
 rename net/xfrm/{xfrm_interface.c => xfrm_interface_core.c} (100%)

diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 494aa744bfb9..08a2870fdd36 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -3,6 +3,8 @@
 # Makefile for the XFRM subsystem.
 #
 
+xfrm_interface-$(CONFIG_XFRM_INTERFACE) += xfrm_interface_core.o
+
 obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
 		      xfrm_input.o xfrm_output.o \
 		      xfrm_sysctl.o xfrm_replay.o xfrm_device.o
diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface_core.c
similarity index 100%
rename from net/xfrm/xfrm_interface.c
rename to net/xfrm/xfrm_interface_core.c
-- 
2.34.1

[PATCH bpf-next,v6 2/4] xfrm: interface: Add unstable helpers for setting/getting XFRM metadata from TC-BPF

[Eyal Birger]

This change adds xfrm metadata helpers using the unstable kfunc call
interface for the TC-BPF hooks. This allows steering traffic towards
different IPsec connections based on logic implemented in bpf programs.

This object is built based on the availability of BTF debug info.

When setting the xfrm metadata, percpu metadata dsts are used in order
to avoid allocating a metadata dst per packet.

In order to guarantee safe module unload, the percpu dsts are allocated
on first use and never freed. The percpu pointer is stored in
net/core/filter.c so that it can be reused on module reload.

The metadata percpu dsts take ownership of the original skb dsts so
that they may be used as part of the xfrm transmission logic - e.g.
for MTU calculations.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>

---

v6:
  fix sparse warning:
  "symbol 'xfrm_bpf_md_dst' was not declared. Should it be static?"
  by moving the xfrm_bpf_md_dst declaration to xfrm.h

v5:
  - remove cleanup of percpu dsts as suggested by Martin KaFai Lau
  - remove redundant extern in header file

v4: changes requested by Martin KaFai Lau:
  - add kfunc documentation
  - remove redundant memset
  - minor coding

v3:
  - remove redunant memset() as suggested by Martin KaFai Lau
  - remove __exit annotation from cleanup() function as it's used from
    an __init function

v2: changed added following points raised by Martin KaFai Lau:
  - make sure dst is refcounted prior to caching
  - free dst_orig regardless of CONFIG_DST_CACHE
  - call xfrm interface bpf cleanup in case of kfunc registration errors
---
 include/net/dst_metadata.h     |   1 +
 include/net/xfrm.h             |  17 +++++
 net/core/dst.c                 |   8 ++-
 net/core/filter.c              |   9 +++
 net/xfrm/Makefile              |   6 ++
 net/xfrm/xfrm_interface_bpf.c  | 115 +++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_interface_core.c |  14 ++++
 7 files changed, 168 insertions(+), 2 deletions(-)
 create mode 100644 net/xfrm/xfrm_interface_bpf.c

diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h
index a454cf4327fe..1b7fae4c6b24 100644
--- a/include/net/dst_metadata.h
+++ b/include/net/dst_metadata.h
@@ -26,6 +26,7 @@ struct macsec_info {
 struct xfrm_md_info {
 	u32 if_id;
 	int link;
+	struct dst_entry *dst_orig;
 };
 
 struct metadata_dst {
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index e0cc6791c001..3707e6b34e67 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -2086,4 +2086,21 @@ static inline bool xfrm6_local_dontfrag(const struct sock *sk)
 	return false;
 }
 #endif
+
+#if (IS_BUILTIN(CONFIG_XFRM_INTERFACE) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) || \
+    (IS_MODULE(CONFIG_XFRM_INTERFACE) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
+
+extern struct metadata_dst __percpu *xfrm_bpf_md_dst;
+
+int register_xfrm_interface_bpf(void);
+
+#else
+
+static inline int register_xfrm_interface_bpf(void)
+{
+	return 0;
+}
+
+#endif
+
 #endif	/* _NET_XFRM_H */
diff --git a/net/core/dst.c b/net/core/dst.c
index bc9c9be4e080..bb14a0392388 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -316,6 +316,8 @@ void metadata_dst_free(struct metadata_dst *md_dst)
 	if (md_dst->type == METADATA_IP_TUNNEL)
 		dst_cache_destroy(&md_dst->u.tun_info.dst_cache);
 #endif
+	if (md_dst->type == METADATA_XFRM)
+		dst_release(md_dst->u.xfrm_info.dst_orig);
 	kfree(md_dst);
 }
 EXPORT_SYMBOL_GPL(metadata_dst_free);
@@ -340,16 +342,18 @@ EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);
 
 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst)
 {
-#ifdef CONFIG_DST_CACHE
 	int cpu;
 
 	for_each_possible_cpu(cpu) {
 		struct metadata_dst *one_md_dst = per_cpu_ptr(md_dst, cpu);
 
+#ifdef CONFIG_DST_CACHE
 		if (one_md_dst->type == METADATA_IP_TUNNEL)
 			dst_cache_destroy(&one_md_dst->u.tun_info.dst_cache);
-	}
 #endif
+		if (one_md_dst->type == METADATA_XFRM)
+			dst_release(one_md_dst->u.xfrm_info.dst_orig);
+	}
 	free_percpu(md_dst);
 }
 EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);
diff --git a/net/core/filter.c b/net/core/filter.c
index 37baaa6b8fc3..328d382fcea0 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5630,6 +5630,15 @@ static const struct bpf_func_proto bpf_bind_proto = {
 };
 
 #ifdef CONFIG_XFRM
+
+#if (IS_BUILTIN(CONFIG_XFRM_INTERFACE) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) || \
+    (IS_MODULE(CONFIG_XFRM_INTERFACE) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
+
+struct metadata_dst __percpu *xfrm_bpf_md_dst;
+EXPORT_SYMBOL_GPL(xfrm_bpf_md_dst);
+
+#endif
+
 BPF_CALL_5(bpf_skb_get_xfrm_state, struct sk_buff *, skb, u32, index,
 	   struct bpf_xfrm_state *, to, u32, size, u64, flags)
 {
diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 08a2870fdd36..cd47f88921f5 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -5,6 +5,12 @@
 
 xfrm_interface-$(CONFIG_XFRM_INTERFACE) += xfrm_interface_core.o
 
+ifeq ($(CONFIG_XFRM_INTERFACE),m)
+xfrm_interface-$(CONFIG_DEBUG_INFO_BTF_MODULES) += xfrm_interface_bpf.o
+else ifeq ($(CONFIG_XFRM_INTERFACE),y)
+xfrm_interface-$(CONFIG_DEBUG_INFO_BTF) += xfrm_interface_bpf.o
+endif
+
 obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
 		      xfrm_input.o xfrm_output.o \
 		      xfrm_sysctl.o xfrm_replay.o xfrm_device.o
diff --git a/net/xfrm/xfrm_interface_bpf.c b/net/xfrm/xfrm_interface_bpf.c
new file mode 100644
index 000000000000..1ef2162cebcf
--- /dev/null
+++ b/net/xfrm/xfrm_interface_bpf.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Unstable XFRM Helpers for TC-BPF hook
+ *
+ * These are called from SCHED_CLS BPF programs. Note that it is
+ * allowed to break compatibility for these functions since the interface they
+ * are exposed through to BPF programs is explicitly unstable.
+ */
+
+#include <linux/bpf.h>
+#include <linux/btf_ids.h>
+
+#include <net/dst_metadata.h>
+#include <net/xfrm.h>
+
+/* bpf_xfrm_info - XFRM metadata information
+ *
+ * Members:
+ * @if_id	- XFRM if_id:
+ *		    Transmit: if_id to be used in policy and state lookups
+ *		    Receive: if_id of the state matched for the incoming packet
+ * @link	- Underlying device ifindex:
+ *		    Transmit: used as the underlying device in VRF routing
+ *		    Receive: the device on which the packet had been received
+ */
+struct bpf_xfrm_info {
+	u32 if_id;
+	int link;
+};
+
+__diag_push();
+__diag_ignore_all("-Wmissing-prototypes",
+		  "Global functions as their definitions will be in xfrm_interface BTF");
+
+/* bpf_skb_get_xfrm_info - Get XFRM metadata
+ *
+ * Parameters:
+ * @skb_ctx	- Pointer to ctx (__sk_buff) in TC program
+ *		    Cannot be NULL
+ * @to		- Pointer to memory to which the metadata will be copied
+ *		    Cannot be NULL
+ */
+__used noinline
+int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx, struct bpf_xfrm_info *to)
+{
+	struct sk_buff *skb = (struct sk_buff *)skb_ctx;
+	struct xfrm_md_info *info;
+
+	info = skb_xfrm_md_info(skb);
+	if (!info)
+		return -EINVAL;
+
+	to->if_id = info->if_id;
+	to->link = info->link;
+	return 0;
+}
+
+/* bpf_skb_get_xfrm_info - Set XFRM metadata
+ *
+ * Parameters:
+ * @skb_ctx	- Pointer to ctx (__sk_buff) in TC program
+ *		    Cannot be NULL
+ * @from	- Pointer to memory from which the metadata will be copied
+ *		    Cannot be NULL
+ */
+__used noinline
+int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx,
+			  const struct bpf_xfrm_info *from)
+{
+	struct sk_buff *skb = (struct sk_buff *)skb_ctx;
+	struct metadata_dst *md_dst;
+	struct xfrm_md_info *info;
+
+	if (unlikely(skb_metadata_dst(skb)))
+		return -EINVAL;
+
+	if (!xfrm_bpf_md_dst) {
+		struct metadata_dst __percpu *tmp;
+
+		tmp = metadata_dst_alloc_percpu(0, METADATA_XFRM, GFP_ATOMIC);
+		if (!tmp)
+			return -ENOMEM;
+		if (cmpxchg(&xfrm_bpf_md_dst, NULL, tmp))
+			metadata_dst_free_percpu(tmp);
+	}
+	md_dst = this_cpu_ptr(xfrm_bpf_md_dst);
+
+	info = &md_dst->u.xfrm_info;
+
+	info->if_id = from->if_id;
+	info->link = from->link;
+	skb_dst_force(skb);
+	info->dst_orig = skb_dst(skb);
+
+	dst_hold((struct dst_entry *)md_dst);
+	skb_dst_set(skb, (struct dst_entry *)md_dst);
+	return 0;
+}
+
+__diag_pop()
+
+BTF_SET8_START(xfrm_ifc_kfunc_set)
+BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
+BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
+BTF_SET8_END(xfrm_ifc_kfunc_set)
+
+static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
+	.owner = THIS_MODULE,
+	.set   = &xfrm_ifc_kfunc_set,
+};
+
+int __init register_xfrm_interface_bpf(void)
+{
+	return register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
+					 &xfrm_interface_kfunc_set);
+}
diff --git a/net/xfrm/xfrm_interface_core.c b/net/xfrm/xfrm_interface_core.c
index 5a67b120c4db..1f99dc469027 100644
--- a/net/xfrm/xfrm_interface_core.c
+++ b/net/xfrm/xfrm_interface_core.c
@@ -396,6 +396,14 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 
 		if_id = md_info->if_id;
 		fl->flowi_oif = md_info->link;
+		if (md_info->dst_orig) {
+			struct dst_entry *tmp_dst = dst;
+
+			dst = md_info->dst_orig;
+			skb_dst_set(skb, dst);
+			md_info->dst_orig = NULL;
+			dst_release(tmp_dst);
+		}
 	} else {
 		if_id = xi->p.if_id;
 	}
@@ -1162,12 +1170,18 @@ static int __init xfrmi_init(void)
 	if (err < 0)
 		goto rtnl_link_failed;
 
+	err = register_xfrm_interface_bpf();
+	if (err < 0)
+		goto kfunc_failed;
+
 	lwtunnel_encap_add_ops(&xfrmi_encap_ops, LWTUNNEL_ENCAP_XFRM);
 
 	xfrm_if_register_cb(&xfrm_if_cb);
 
 	return err;
 
+kfunc_failed:
+	rtnl_link_unregister(&xfrmi_link_ops);
 rtnl_link_failed:
 	xfrmi6_fini();
 xfrmi6_failed:
-- 
2.34.1

[PATCH bpf-next,v6 3/4] tools: add IFLA_XFRM_COLLECT_METADATA to uapi/linux/if_link.h

[Eyal Birger]

Needed for XFRM metadata tests.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
---
 tools/include/uapi/linux/if_link.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/include/uapi/linux/if_link.h b/tools/include/uapi/linux/if_link.h
index 0242f31e339c..901d98b865a1 100644
--- a/tools/include/uapi/linux/if_link.h
+++ b/tools/include/uapi/linux/if_link.h
@@ -673,6 +673,7 @@ enum {
 	IFLA_XFRM_UNSPEC,
 	IFLA_XFRM_LINK,
 	IFLA_XFRM_IF_ID,
+	IFLA_XFRM_COLLECT_METADATA,
 	__IFLA_XFRM_MAX
 };
 
-- 
2.34.1

[PATCH bpf-next,v6 4/4] selftests/bpf: add xfrm_info tests

[Eyal Birger]

Test the xfrm_info kfunc helpers.

The test setup creates three name spaces - NS0, NS1, NS2.

XFRM tunnels are setup between NS0 and the two other NSs.

The kfunc helpers are used to steer traffic from NS0 to the other
NSs based on a userspace populated bpf global variable and validate
that the return traffic had arrived from the desired NS.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>

---
v4: changes suggested by Martin KaFai Lau:
  - minor coding and wording changes
  - use vmlinux.h and bpf_tracing_net.h in test program
  - avoid running on s390x in CI as kfuncs aren't supported there

v3: changes suggested by Martin KaFai Lau:
  - rename test_xfrm_info{,_kern}.c -> xfrm_info.c
  - avoid running in a separate thread
  - simplify test setup
  - verify underlay/overlay success
  - create NS0 xfrmi external device using netlink to avoid dependency
    on newer iproute2
  - remove use of bpf_trace_printk() in test programs
  - add "preserve_access_index" attribute annotation in test program
    struct definition
  - use bss variables access instead of a map for userspace/bpf interface

v2:
  - use an lwt route in NS1 for testing that flow as well
  - indendation fix
---
 tools/testing/selftests/bpf/DENYLIST.s390x    |   1 +
 tools/testing/selftests/bpf/config            |   2 +
 .../selftests/bpf/prog_tests/xfrm_info.c      | 365 ++++++++++++++++++
 .../selftests/bpf/progs/bpf_tracing_net.h     |   3 +
 tools/testing/selftests/bpf/progs/xfrm_info.c |  35 ++
 5 files changed, 406 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/xfrm_info.c
 create mode 100644 tools/testing/selftests/bpf/progs/xfrm_info.c

diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
index 3481f3a5ea6f..585fcf73c731 100644
--- a/tools/testing/selftests/bpf/DENYLIST.s390x
+++ b/tools/testing/selftests/bpf/DENYLIST.s390x
@@ -85,3 +85,4 @@ xdp_bonding                              # failed to auto-attach program 'trace_
 xdp_bpf2bpf                              # failed to auto-attach program 'trace_on_entry': -524                        (trampoline)
 xdp_do_redirect                          # prog_run_max_size unexpected error: -22 (errno 22)
 xdp_synproxy                             # JIT does not support calling kernel function                                (kfunc)
+xfrm_info                                # JIT does not support calling kernel function                                (kfunc)
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index f9034ea00bc9..3543c76cef56 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -23,6 +23,7 @@ CONFIG_IKCONFIG_PROC=y
 CONFIG_IMA=y
 CONFIG_IMA_READ_POLICY=y
 CONFIG_IMA_WRITE_POLICY=y
+CONFIG_INET_ESP=y
 CONFIG_IP_NF_FILTER=y
 CONFIG_IP_NF_RAW=y
 CONFIG_IP_NF_TARGET_SYNPROXY=y
@@ -74,3 +75,4 @@ CONFIG_TEST_BPF=y
 CONFIG_USERFAULTFD=y
 CONFIG_VXLAN=y
 CONFIG_XDP_SOCKETS=y
+CONFIG_XFRM_INTERFACE=y
diff --git a/tools/testing/selftests/bpf/prog_tests/xfrm_info.c b/tools/testing/selftests/bpf/prog_tests/xfrm_info.c
new file mode 100644
index 000000000000..926df2047d2a
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xfrm_info.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+/*
+ * Topology:
+ * ---------
+ *   NS0 namespace         |   NS1 namespace        | NS2 namespace
+ *                         |                        |
+ *   +---------------+     |   +---------------+    |
+ *   |    ipsec0     |---------|    ipsec0     |    |
+ *   | 192.168.1.100 |     |   | 192.168.1.200 |    |
+ *   | if_id: bpf    |     |   +---------------+    |
+ *   +---------------+     |                        |
+ *           |             |                        |   +---------------+
+ *           |             |                        |   |    ipsec0     |
+ *           \------------------------------------------| 192.168.1.200 |
+ *                         |                        |   +---------------+
+ *                         |                        |
+ *                         |                        | (overlay network)
+ *      ------------------------------------------------------
+ *                         |                        | (underlay network)
+ *   +--------------+      |   +--------------+     |
+ *   |    veth01    |----------|    veth10    |     |
+ *   | 172.16.1.100 |      |   | 172.16.1.200 |     |
+ *   ---------------+      |   +--------------+     |
+ *                         |                        |
+ *   +--------------+      |                        |   +--------------+
+ *   |    veth02    |-----------------------------------|    veth20    |
+ *   | 172.16.2.100 |      |                        |   | 172.16.2.200 |
+ *   +--------------+      |                        |   +--------------+
+ *
+ *
+ * Test Packet flow
+ * -----------
+ *  The tests perform 'ping 192.168.1.200' from the NS0 namespace:
+ *  1) request is routed to NS0 ipsec0
+ *  2) NS0 ipsec0 tc egress BPF program is triggered and sets the if_id based
+ *     on the requested value. This makes the ipsec0 device in external mode
+ *     select the destination tunnel
+ *  3) ping reaches the other namespace (NS1 or NS2 based on which if_id was
+ *     used) and response is sent
+ *  4) response is received on NS0 ipsec0, tc ingress program is triggered and
+ *     records the response if_id
+ *  5) requested if_id is compared with received if_id
+ */
+
+#include <net/if.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_link.h>
+
+#include "test_progs.h"
+#include "network_helpers.h"
+#include "xfrm_info.skel.h"
+
+#define NS0 "xfrm_test_ns0"
+#define NS1 "xfrm_test_ns1"
+#define NS2 "xfrm_test_ns2"
+
+#define IF_ID_0_TO_1 1
+#define IF_ID_0_TO_2 2
+#define IF_ID_1 3
+#define IF_ID_2 4
+
+#define IP4_ADDR_VETH01 "172.16.1.100"
+#define IP4_ADDR_VETH10 "172.16.1.200"
+#define IP4_ADDR_VETH02 "172.16.2.100"
+#define IP4_ADDR_VETH20 "172.16.2.200"
+
+#define ESP_DUMMY_PARAMS \
+    "proto esp aead 'rfc4106(gcm(aes))' " \
+    "0xe4d8f4b4da1df18a3510b3781496daa82488b713 128 mode tunnel "
+
+#define PING_ARGS "-i 0.01 -c 3 -w 10 -q"
+
+#define SYS(fmt, ...)						\
+	({							\
+		char cmd[1024];					\
+		snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__);	\
+		if (!ASSERT_OK(system(cmd), cmd))		\
+			goto fail;				\
+	})
+
+#define SYS_NOFAIL(fmt, ...)					\
+	({							\
+		char cmd[1024];					\
+		snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__);	\
+		system(cmd);					\
+	})
+
+static int attach_tc_prog(struct bpf_tc_hook *hook, int igr_fd, int egr_fd)
+{
+	LIBBPF_OPTS(bpf_tc_opts, opts1, .handle = 1, .priority = 1,
+		    .prog_fd = igr_fd);
+	LIBBPF_OPTS(bpf_tc_opts, opts2, .handle = 1, .priority = 1,
+		    .prog_fd = egr_fd);
+	int ret;
+
+	ret = bpf_tc_hook_create(hook);
+	if (!ASSERT_OK(ret, "create tc hook"))
+		return ret;
+
+	if (igr_fd >= 0) {
+		hook->attach_point = BPF_TC_INGRESS;
+		ret = bpf_tc_attach(hook, &opts1);
+		if (!ASSERT_OK(ret, "bpf_tc_attach")) {
+			bpf_tc_hook_destroy(hook);
+			return ret;
+		}
+	}
+
+	if (egr_fd >= 0) {
+		hook->attach_point = BPF_TC_EGRESS;
+		ret = bpf_tc_attach(hook, &opts2);
+		if (!ASSERT_OK(ret, "bpf_tc_attach")) {
+			bpf_tc_hook_destroy(hook);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void cleanup(void)
+{
+	SYS_NOFAIL("test -f /var/run/netns/" NS0 " && ip netns delete " NS0);
+	SYS_NOFAIL("test -f /var/run/netns/" NS1 " && ip netns delete " NS1);
+	SYS_NOFAIL("test -f /var/run/netns/" NS2 " && ip netns delete " NS2);
+}
+
+static int config_underlay(void)
+{
+	SYS("ip netns add " NS0);
+	SYS("ip netns add " NS1);
+	SYS("ip netns add " NS2);
+
+	/* NS0 <-> NS1 [veth01 <-> veth10] */
+	SYS("ip link add veth01 netns " NS0 " type veth peer name veth10 netns " NS1);
+	SYS("ip -net " NS0 " addr add " IP4_ADDR_VETH01 "/24 dev veth01");
+	SYS("ip -net " NS0 " link set dev veth01 up");
+	SYS("ip -net " NS1 " addr add " IP4_ADDR_VETH10 "/24 dev veth10");
+	SYS("ip -net " NS1 " link set dev veth10 up");
+
+	/* NS0 <-> NS2 [veth02 <-> veth20] */
+	SYS("ip link add veth02 netns " NS0 " type veth peer name veth20 netns " NS2);
+	SYS("ip -net " NS0 " addr add " IP4_ADDR_VETH02 "/24 dev veth02");
+	SYS("ip -net " NS0 " link set dev veth02 up");
+	SYS("ip -net " NS2 " addr add " IP4_ADDR_VETH20 "/24 dev veth20");
+	SYS("ip -net " NS2 " link set dev veth20 up");
+
+	return 0;
+fail:
+	return -1;
+}
+
+static int setup_xfrm_tunnel_ns(const char *ns, const char *ipv4_local,
+				const char *ipv4_remote, int if_id)
+{
+	/* State: local -> remote */
+	SYS("ip -net %s xfrm state add src %s dst %s spi 1 "
+	    ESP_DUMMY_PARAMS "if_id %d", ns, ipv4_local, ipv4_remote, if_id);
+
+	/* State: local <- remote */
+	SYS("ip -net %s xfrm state add src %s dst %s spi 1 "
+	    ESP_DUMMY_PARAMS "if_id %d", ns, ipv4_remote, ipv4_local, if_id);
+
+	/* Policy: local -> remote */
+	SYS("ip -net %s xfrm policy add dir out src 0.0.0.0/0 dst 0.0.0.0/0 "
+	    "if_id %d tmpl src %s dst %s proto esp mode tunnel if_id %d", ns,
+	    if_id, ipv4_local, ipv4_remote, if_id);
+
+	/* Policy: local <- remote */
+	SYS("ip -net %s xfrm policy add dir in src 0.0.0.0/0 dst 0.0.0.0/0 "
+	    "if_id %d tmpl src %s dst %s proto esp mode tunnel if_id %d", ns,
+	    if_id, ipv4_remote, ipv4_local, if_id);
+
+	return 0;
+fail:
+	return -1;
+}
+
+static int setup_xfrm_tunnel(const char *ns_a, const char *ns_b,
+			     const char *ipv4_a, const char *ipv4_b,
+			     int if_id_a, int if_id_b)
+{
+	return setup_xfrm_tunnel_ns(ns_a, ipv4_a, ipv4_b, if_id_a) ||
+		setup_xfrm_tunnel_ns(ns_b, ipv4_b, ipv4_a, if_id_b);
+}
+
+static struct rtattr *rtattr_add(struct nlmsghdr *nh, unsigned short type,
+				 unsigned short len)
+{
+	struct rtattr *rta =
+		(struct rtattr *)((uint8_t *)nh + RTA_ALIGN(nh->nlmsg_len));
+	rta->rta_type = type;
+	rta->rta_len = RTA_LENGTH(len);
+	nh->nlmsg_len = RTA_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len);
+	return rta;
+}
+
+static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type,
+				     const char *s)
+{
+	struct rtattr *rta = rtattr_add(nh, type, strlen(s));
+
+	memcpy(RTA_DATA(rta), s, strlen(s));
+	return rta;
+}
+
+static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short type)
+{
+	return rtattr_add(nh, type, 0);
+}
+
+static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr)
+{
+	uint8_t *end = (uint8_t *)nh + nh->nlmsg_len;
+
+	attr->rta_len = end - (uint8_t *)attr;
+}
+
+static int setup_xfrmi_external_dev(const char *ns)
+{
+	struct {
+		struct nlmsghdr nh;
+		struct ifinfomsg info;
+		unsigned char data[128];
+	} req;
+	struct rtattr *link_info, *info_data;
+	struct nstoken *nstoken;
+	int ret = -1, sock = -1;
+	struct nlmsghdr *nh;
+
+	memset(&req, 0, sizeof(req));
+	nh = &req.nh;
+	nh->nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
+	nh->nlmsg_type = RTM_NEWLINK;
+	nh->nlmsg_flags |= NLM_F_CREATE | NLM_F_REQUEST;
+
+	rtattr_add_str(nh, IFLA_IFNAME, "ipsec0");
+	link_info = rtattr_begin(nh, IFLA_LINKINFO);
+	rtattr_add_str(nh, IFLA_INFO_KIND, "xfrm");
+	info_data = rtattr_begin(nh, IFLA_INFO_DATA);
+	rtattr_add(nh, IFLA_XFRM_COLLECT_METADATA, 0);
+	rtattr_end(nh, info_data);
+	rtattr_end(nh, link_info);
+
+	nstoken = open_netns(ns);
+	if (!ASSERT_OK_PTR(nstoken, "setns"))
+		goto done;
+
+	sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);
+	if (!ASSERT_GE(sock, 0, "netlink socket"))
+		goto done;
+	ret = send(sock, nh, nh->nlmsg_len, 0);
+	if (!ASSERT_EQ(ret, nh->nlmsg_len, "netlink send length"))
+		goto done;
+
+	ret = 0;
+done:
+	if (sock != -1)
+		close(sock);
+	if (nstoken)
+		close_netns(nstoken);
+	return ret;
+}
+
+static int config_overlay(void)
+{
+	if (setup_xfrm_tunnel(NS0, NS1, IP4_ADDR_VETH01, IP4_ADDR_VETH10,
+			      IF_ID_0_TO_1, IF_ID_1))
+		goto fail;
+	if (setup_xfrm_tunnel(NS0, NS2, IP4_ADDR_VETH02, IP4_ADDR_VETH20,
+			      IF_ID_0_TO_2, IF_ID_2))
+		goto fail;
+
+	/* Older iproute2 doesn't support this option */
+	if (!ASSERT_OK(setup_xfrmi_external_dev(NS0), "xfrmi"))
+		goto fail;
+
+	SYS("ip -net " NS0 " addr add 192.168.1.100/24 dev ipsec0");
+	SYS("ip -net " NS0 " link set dev ipsec0 up");
+
+	SYS("ip -net " NS1 " link add ipsec0 type xfrm if_id %d", IF_ID_1);
+	SYS("ip -net " NS1 " addr add 192.168.1.200/24 dev ipsec0");
+	SYS("ip -net " NS1 " link set dev ipsec0 up");
+
+	SYS("ip -net " NS2 " link add ipsec0 type xfrm if_id %d", IF_ID_2);
+	SYS("ip -net " NS2 " addr add 192.168.1.200/24 dev ipsec0");
+	SYS("ip -net " NS2 " link set dev ipsec0 up");
+
+	return 0;
+fail:
+	return -1;
+}
+
+static int test_xfrm_ping(struct xfrm_info *skel, u32 if_id)
+{
+	skel->bss->req_if_id = if_id;
+
+	SYS("ping -i 0.01 -c 3 -w 10 -q 192.168.1.200 > /dev/null");
+
+	if (!ASSERT_EQ(skel->bss->resp_if_id, if_id, "if_id"))
+		goto fail;
+
+	return 0;
+fail:
+	return -1;
+}
+
+static void _test_xfrm_info(void)
+{
+	LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
+	int get_xfrm_info_prog_fd, set_xfrm_info_prog_fd;
+	struct xfrm_info *skel = NULL;
+	struct nstoken *nstoken = NULL;
+	int ifindex;
+
+	/* load and attach bpf progs to ipsec dev tc hook point */
+	skel = xfrm_info__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "xfrm_info__open_and_load"))
+		goto done;
+	nstoken = open_netns(NS0);
+	if (!ASSERT_OK_PTR(nstoken, "setns " NS0))
+		goto done;
+	ifindex = if_nametoindex("ipsec0");
+	if (!ASSERT_NEQ(ifindex, 0, "ipsec0 ifindex"))
+		goto done;
+	tc_hook.ifindex = ifindex;
+	set_xfrm_info_prog_fd = bpf_program__fd(skel->progs.set_xfrm_info);
+	get_xfrm_info_prog_fd = bpf_program__fd(skel->progs.get_xfrm_info);
+	if (!ASSERT_GE(set_xfrm_info_prog_fd, 0, "bpf_program__fd"))
+		goto done;
+	if (!ASSERT_GE(get_xfrm_info_prog_fd, 0, "bpf_program__fd"))
+		goto done;
+	if (attach_tc_prog(&tc_hook, get_xfrm_info_prog_fd,
+			   set_xfrm_info_prog_fd))
+		goto done;
+
+	/* perform test */
+	if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_1), 0, "ping " NS1))
+		goto done;
+	if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_2), 0, "ping " NS2))
+		goto done;
+
+done:
+	if (nstoken)
+		close_netns(nstoken);
+	if (skel)
+		xfrm_info__destroy(skel);
+}
+
+void test_xfrm_info(void)
+{
+	cleanup();
+
+	if (!ASSERT_OK(config_underlay(), "config_underlay"))
+		goto done;
+	if (!ASSERT_OK(config_overlay(), "config_overlay"))
+		goto done;
+
+	if (test__start_subtest("xfrm_info"))
+		_test_xfrm_info();
+
+done:
+	cleanup();
+}
diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
index adb087aecc9e..b394817126cf 100644
--- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
+++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
@@ -25,6 +25,9 @@
 #define IPV6_TCLASS		67
 #define IPV6_AUTOFLOWLABEL	70
 
+#define TC_ACT_UNSPEC		(-1)
+#define TC_ACT_SHOT		2
+
 #define SOL_TCP			6
 #define TCP_NODELAY		1
 #define TCP_MAXSEG		2
diff --git a/tools/testing/selftests/bpf/progs/xfrm_info.c b/tools/testing/selftests/bpf/progs/xfrm_info.c
new file mode 100644
index 000000000000..3acedcdd962d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/xfrm_info.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "vmlinux.h"
+#include "bpf_tracing_net.h"
+#include <bpf/bpf_helpers.h>
+
+__u32 req_if_id;
+__u32 resp_if_id;
+
+int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx,
+			  const struct bpf_xfrm_info *from) __ksym;
+int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx,
+			  struct bpf_xfrm_info *to) __ksym;
+
+SEC("tc")
+int set_xfrm_info(struct __sk_buff *skb)
+{
+	struct bpf_xfrm_info info = { .if_id = req_if_id };
+
+	return bpf_skb_set_xfrm_info(skb, &info) ? TC_ACT_SHOT : TC_ACT_UNSPEC;
+}
+
+SEC("tc")
+int get_xfrm_info(struct __sk_buff *skb)
+{
+	struct bpf_xfrm_info info = {};
+
+	if (bpf_skb_get_xfrm_info(skb, &info) < 0)
+		return TC_ACT_SHOT;
+
+	resp_if_id = info.if_id;
+
+	return TC_ACT_UNSPEC;
+}
+
+char _license[] SEC("license") = "GPL";
-- 
2.34.1

Re: [PATCH bpf-next,v6 0/4] xfrm: interface: Add unstable helpers for XFRM metadata

[patchwork-bot+netdevbpf]

Hello:

This series was applied to bpf/bpf-next.git (master)
by Martin KaFai Lau <martin.lau@kernel.org>:

On Sat,  3 Dec 2022 10:46:55 +0200 you wrote:
> This patch series adds xfrm metadata helpers using the unstable kfunc
> call interface for the TC-BPF hooks.
> 
> This allows steering traffic towards different IPsec connections based
> on logic implemented in bpf programs.
> 
> The helpers are integrated into the xfrm_interface module. For this
> purpose the main functionality of this module is moved to
> xfrm_interface_core.c.
> 
> [...]

Here is the summary with links:
  - [bpf-next,v6,1/4] xfrm: interface: rename xfrm_interface.c to xfrm_interface_core.c
    https://git.kernel.org/bpf/bpf-next/c/ee9a113ab634
  - [bpf-next,v6,2/4] xfrm: interface: Add unstable helpers for setting/getting XFRM metadata from TC-BPF
    https://git.kernel.org/bpf/bpf-next/c/94151f5aa966
  - [bpf-next,v6,3/4] tools: add IFLA_XFRM_COLLECT_METADATA to uapi/linux/if_link.h
    https://git.kernel.org/bpf/bpf-next/c/4f4ac4d9106e
  - [bpf-next,v6,4/4] selftests/bpf: add xfrm_info tests
    https://git.kernel.org/bpf/bpf-next/c/90a3a05eb33f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH bpf-next,v6 4/4] selftests/bpf: add xfrm_info tests

[Martin KaFai Lau]

On 12/3/22 12:46 AM, Eyal Birger wrote:
> +#define PING_ARGS "-i 0.01 -c 3 -w 10 -q"

Applied with a few changes.

PING_ARGS is removed because it is unused.

[ ... ]

> +static int test_xfrm_ping(struct xfrm_info *skel, u32 if_id)
> +{
> +	skel->bss->req_if_id = if_id;
> +
> +	SYS("ping -i 0.01 -c 3 -w 10 -q 192.168.1.200 > /dev/null");
> +
> +	if (!ASSERT_EQ(skel->bss->resp_if_id, if_id, "if_id"))
> +		goto fail;
> +
> +	return 0;
> +fail:
> +	return -1;
> +}
> +
> +static void _test_xfrm_info(void)
> +{
> +	LIBBPF_OPTS(bpf_tc_hook, tc_hook, .attach_point = BPF_TC_INGRESS);
> +	int get_xfrm_info_prog_fd, set_xfrm_info_prog_fd;
> +	struct xfrm_info *skel = NULL;
> +	struct nstoken *nstoken = NULL;
> +	int ifindex;
> +
> +	/* load and attach bpf progs to ipsec dev tc hook point */
> +	skel = xfrm_info__open_and_load();
> +	if (!ASSERT_OK_PTR(skel, "xfrm_info__open_and_load"))
> +		goto done;
> +	nstoken = open_netns(NS0);
> +	if (!ASSERT_OK_PTR(nstoken, "setns " NS0))
> +		goto done;
> +	ifindex = if_nametoindex("ipsec0");
> +	if (!ASSERT_NEQ(ifindex, 0, "ipsec0 ifindex"))
> +		goto done;
> +	tc_hook.ifindex = ifindex;
> +	set_xfrm_info_prog_fd = bpf_program__fd(skel->progs.set_xfrm_info);
> +	get_xfrm_info_prog_fd = bpf_program__fd(skel->progs.get_xfrm_info);
> +	if (!ASSERT_GE(set_xfrm_info_prog_fd, 0, "bpf_program__fd"))
> +		goto done;
> +	if (!ASSERT_GE(get_xfrm_info_prog_fd, 0, "bpf_program__fd"))
> +		goto done;
> +	if (attach_tc_prog(&tc_hook, get_xfrm_info_prog_fd,
> +			   set_xfrm_info_prog_fd))
> +		goto done;
> +
> +	/* perform test */
> +	if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_1), 0, "ping " NS1))
> +		goto done;
> +	if (!ASSERT_EQ(test_xfrm_ping(skel, IF_ID_0_TO_2), 0, "ping " NS2))
> +		goto done;
> +
> +done:
> +	if (nstoken)
> +		close_netns(nstoken);
> +	if (skel)

NULL check is removed.  xfrm_info__destroy() can handle NULL.

> +		xfrm_info__destroy(skel);
> +}