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authorYonghong Song <yhs@fb.com>2017-05-02 19:58:14 -0700
committerDavid S. Miller <davem@davemloft.net>2017-05-03 09:51:25 -0400
commit6ead18fb18c8182a81d70f24942f9547e56a35d2 (patch)
tree06dfd33dbb26086f8cc593f51a6e47f53f784200 /tools
parent4d463c4dbc5c1c5d73e488d52faeec05570443a0 (diff)
downloadlinux-sh-6ead18fb18c8182a81d70f24942f9547e56a35d2.tar.gz
selftests/bpf: add a test case to check verifier pointer arithmetic
With clang/llvm 4.0+, the test case is able to generate the following pattern: .... 440: (b7) r1 = 15 441: (05) goto pc+73 515: (79) r6 = *(u64 *)(r10 -152) 516: (bf) r7 = r10 517: (07) r7 += -112 518: (bf) r2 = r7 519: (0f) r2 += r1 520: (71) r1 = *(u8 *)(r8 +0) 521: (73) *(u8 *)(r2 +45) = r1 .... commit 332270fdc8b6 ("bpf: enhance verifier to understand stack pointer arithmetic") improved verifier to handle such a pattern. This patch adds a C test case to actually generate such a pattern. A dummy tracepoint interface is used to load the program into the kernel. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/bpf/Makefile2
-rw-r--r--tools/testing/selftests/bpf/test_progs.c16
-rw-r--r--tools/testing/selftests/bpf/test_tcp_estats.c258
3 files changed, 275 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index d8d94b9bd76c..f4341e160de6 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -13,7 +13,7 @@ LDLIBS += -lcap -lelf
TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs
-TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o
+TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o
TEST_PROGS := test_kmod.sh
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 4ed049a0b14b..b59f5ed4ae40 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -268,6 +268,21 @@ out:
bpf_object__close(obj);
}
+static void test_tcp_estats(void)
+{
+ const char *file = "./test_tcp_estats.o";
+ int err, prog_fd;
+ struct bpf_object *obj;
+ __u32 duration = 0;
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
+ CHECK(err, "", "err %d errno %d\n", err, errno);
+ if (err)
+ return;
+
+ bpf_object__close(obj);
+}
+
int main(void)
{
struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
@@ -277,6 +292,7 @@ int main(void)
test_pkt_access();
test_xdp();
test_l4lb();
+ test_tcp_estats();
printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
return 0;
diff --git a/tools/testing/selftests/bpf/test_tcp_estats.c b/tools/testing/selftests/bpf/test_tcp_estats.c
new file mode 100644
index 000000000000..bee3bbecc0c4
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_tcp_estats.c
@@ -0,0 +1,258 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+/* This program shows clang/llvm is able to generate code pattern
+ * like:
+ * _tcp_send_active_reset:
+ * 0: bf 16 00 00 00 00 00 00 r6 = r1
+ * ......
+ * 335: b7 01 00 00 0f 00 00 00 r1 = 15
+ * 336: 05 00 48 00 00 00 00 00 goto 72
+ *
+ * LBB0_3:
+ * 337: b7 01 00 00 01 00 00 00 r1 = 1
+ * 338: 63 1a d0 ff 00 00 00 00 *(u32 *)(r10 - 48) = r1
+ * 408: b7 01 00 00 03 00 00 00 r1 = 3
+ *
+ * LBB0_4:
+ * 409: 71 a2 fe ff 00 00 00 00 r2 = *(u8 *)(r10 - 2)
+ * 410: bf a7 00 00 00 00 00 00 r7 = r10
+ * 411: 07 07 00 00 b8 ff ff ff r7 += -72
+ * 412: bf 73 00 00 00 00 00 00 r3 = r7
+ * 413: 0f 13 00 00 00 00 00 00 r3 += r1
+ * 414: 73 23 2d 00 00 00 00 00 *(u8 *)(r3 + 45) = r2
+ *
+ * From the above code snippet, the code generated by the compiler
+ * is reasonable. The "r1" is assigned to different values in basic
+ * blocks "_tcp_send_active_reset" and "LBB0_3", and used in "LBB0_4".
+ * The verifier should be able to handle such code patterns.
+ */
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/ipv6.h>
+#include <linux/version.h>
+#include <sys/socket.h>
+#include "bpf_helpers.h"
+
+#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
+#define TCP_ESTATS_MAGIC 0xBAADBEEF
+
+/* This test case needs "sock" and "pt_regs" data structure.
+ * Recursively, "sock" needs "sock_common" and "inet_sock".
+ * However, this is a unit test case only for
+ * verifier purpose without bpf program execution.
+ * We can safely mock much simpler data structures, basically
+ * only taking the necessary fields from kernel headers.
+ */
+typedef __u32 __bitwise __portpair;
+typedef __u64 __bitwise __addrpair;
+
+struct sock_common {
+ unsigned short skc_family;
+ union {
+ __addrpair skc_addrpair;
+ struct {
+ __be32 skc_daddr;
+ __be32 skc_rcv_saddr;
+ };
+ };
+ union {
+ __portpair skc_portpair;
+ struct {
+ __be16 skc_dport;
+ __u16 skc_num;
+ };
+ };
+ struct in6_addr skc_v6_daddr;
+ struct in6_addr skc_v6_rcv_saddr;
+};
+
+struct sock {
+ struct sock_common __sk_common;
+#define sk_family __sk_common.skc_family
+#define sk_v6_daddr __sk_common.skc_v6_daddr
+#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
+};
+
+struct inet_sock {
+ struct sock sk;
+#define inet_daddr sk.__sk_common.skc_daddr
+#define inet_dport sk.__sk_common.skc_dport
+ __be32 inet_saddr;
+ __be16 inet_sport;
+};
+
+struct pt_regs {
+ long di;
+};
+
+static inline struct inet_sock *inet_sk(const struct sock *sk)
+{
+ return (struct inet_sock *)sk;
+}
+
+/* Define various data structures for state recording.
+ * Some fields are not used due to test simplification.
+ */
+enum tcp_estats_addrtype {
+ TCP_ESTATS_ADDRTYPE_IPV4 = 1,
+ TCP_ESTATS_ADDRTYPE_IPV6 = 2
+};
+
+enum tcp_estats_event_type {
+ TCP_ESTATS_ESTABLISH,
+ TCP_ESTATS_PERIODIC,
+ TCP_ESTATS_TIMEOUT,
+ TCP_ESTATS_RETRANSMIT_TIMEOUT,
+ TCP_ESTATS_RETRANSMIT_OTHER,
+ TCP_ESTATS_SYN_RETRANSMIT,
+ TCP_ESTATS_SYNACK_RETRANSMIT,
+ TCP_ESTATS_TERM,
+ TCP_ESTATS_TX_RESET,
+ TCP_ESTATS_RX_RESET,
+ TCP_ESTATS_WRITE_TIMEOUT,
+ TCP_ESTATS_CONN_TIMEOUT,
+ TCP_ESTATS_ACK_LATENCY,
+ TCP_ESTATS_NEVENTS,
+};
+
+struct tcp_estats_event {
+ int pid;
+ int cpu;
+ unsigned long ts;
+ unsigned int magic;
+ enum tcp_estats_event_type event_type;
+};
+
+/* The below data structure is packed in order for
+ * llvm compiler to generate expected code.
+ */
+struct tcp_estats_conn_id {
+ unsigned int localaddressType;
+ struct {
+ unsigned char data[16];
+ } localaddress;
+ struct {
+ unsigned char data[16];
+ } remaddress;
+ unsigned short localport;
+ unsigned short remport;
+} __attribute__((__packed__));
+
+struct tcp_estats_basic_event {
+ struct tcp_estats_event event;
+ struct tcp_estats_conn_id conn_id;
+};
+
+struct bpf_map_def SEC("maps") ev_record_map = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(struct tcp_estats_basic_event),
+ .max_entries = 1024,
+};
+
+struct dummy_tracepoint_args {
+ unsigned long long pad;
+ struct sock *sock;
+};
+
+static __always_inline void tcp_estats_ev_init(struct tcp_estats_event *event,
+ enum tcp_estats_event_type type)
+{
+ event->magic = TCP_ESTATS_MAGIC;
+ event->ts = bpf_ktime_get_ns();
+ event->event_type = type;
+}
+
+static __always_inline void unaligned_u32_set(unsigned char *to, __u8 *from)
+{
+ to[0] = _(from[0]);
+ to[1] = _(from[1]);
+ to[2] = _(from[2]);
+ to[3] = _(from[3]);
+}
+
+static __always_inline void conn_id_ipv4_init(struct tcp_estats_conn_id *conn_id,
+ __be32 *saddr, __be32 *daddr)
+{
+ conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV4;
+
+ unaligned_u32_set(conn_id->localaddress.data, (__u8 *)saddr);
+ unaligned_u32_set(conn_id->remaddress.data, (__u8 *)daddr);
+}
+
+static __always_inline void conn_id_ipv6_init(struct tcp_estats_conn_id *conn_id,
+ __be32 *saddr, __be32 *daddr)
+{
+ conn_id->localaddressType = TCP_ESTATS_ADDRTYPE_IPV6;
+
+ unaligned_u32_set(conn_id->localaddress.data, (__u8 *)saddr);
+ unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32),
+ (__u8 *)(saddr + 1));
+ unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32) * 2,
+ (__u8 *)(saddr + 2));
+ unaligned_u32_set(conn_id->localaddress.data + sizeof(__u32) * 3,
+ (__u8 *)(saddr + 3));
+
+ unaligned_u32_set(conn_id->remaddress.data,
+ (__u8 *)(daddr));
+ unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32),
+ (__u8 *)(daddr + 1));
+ unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32) * 2,
+ (__u8 *)(daddr + 2));
+ unaligned_u32_set(conn_id->remaddress.data + sizeof(__u32) * 3,
+ (__u8 *)(daddr + 3));
+}
+
+static __always_inline void tcp_estats_conn_id_init(struct tcp_estats_conn_id *conn_id,
+ struct sock *sk)
+{
+ conn_id->localport = _(inet_sk(sk)->inet_sport);
+ conn_id->remport = _(inet_sk(sk)->inet_dport);
+
+ if (_(sk->sk_family) == AF_INET6)
+ conn_id_ipv6_init(conn_id,
+ sk->sk_v6_rcv_saddr.s6_addr32,
+ sk->sk_v6_daddr.s6_addr32);
+ else
+ conn_id_ipv4_init(conn_id,
+ &inet_sk(sk)->inet_saddr,
+ &inet_sk(sk)->inet_daddr);
+}
+
+static __always_inline void tcp_estats_init(struct sock *sk,
+ struct tcp_estats_event *event,
+ struct tcp_estats_conn_id *conn_id,
+ enum tcp_estats_event_type type)
+{
+ tcp_estats_ev_init(event, type);
+ tcp_estats_conn_id_init(conn_id, sk);
+}
+
+static __always_inline void send_basic_event(struct sock *sk,
+ enum tcp_estats_event_type type)
+{
+ struct tcp_estats_basic_event ev;
+ __u32 key = bpf_get_prandom_u32();
+
+ memset(&ev, 0, sizeof(ev));
+ tcp_estats_init(sk, &ev.event, &ev.conn_id, type);
+ bpf_map_update_elem(&ev_record_map, &key, &ev, BPF_ANY);
+}
+
+SEC("dummy_tracepoint")
+int _dummy_tracepoint(struct dummy_tracepoint_args *arg)
+{
+ if (!arg->sock)
+ return 0;
+
+ send_basic_event(arg->sock, TCP_ESTATS_TX_RESET);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */