bpf: add map tests for BPF_PROG_TYPE_SK_MSG

Add map tests to attach BPF_PROG_TYPE_SK_MSG types to a sockmap.

Signed-off-by: John Fastabend <[e-mail]>
Acked-by: David S. Miller <[e-mail]>
Signed-off-by: Daniel Borkmann <[e-mail]>

tools/include/uapi/linux/bpf.h

···
 	BPF_PROG_TYPE_SOCK_OPS,
 	BPF_PROG_TYPE_SK_SKB,
 	BPF_PROG_TYPE_CGROUP_DEVICE,
+	BPF_PROG_TYPE_SK_MSG,
 };
 
 enum bpf_attach_type {
···
 	BPF_SK_SKB_STREAM_PARSER,
 	BPF_SK_SKB_STREAM_VERDICT,
 	BPF_CGROUP_DEVICE,
+	BPF_SK_MSG_VERDICT,
 	__MAX_BPF_ATTACH_TYPE
 };
 
···
 enum sk_action {
 	SK_DROP = 0,
 	SK_PASS,
+};
+
+/* user accessible metadata for SK_MSG packet hook, new fields must
+ * be added to the end of this structure
+ */
+struct sk_msg_md {
+	void *data;
+	void *data_end;
 };
 
 #define BPF_TAG_SIZE	8

tools/testing/selftests/bpf/Makefile

···
 	test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o     \
 	sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o \
 	test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \
-	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o
+	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
+	sockmap_tcp_msg_prog.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \

tools/testing/selftests/bpf/bpf_helpers.h

···
 	(void *) BPF_FUNC_skb_under_cgroup;
 static int (*bpf_skb_change_head)(void *, int len, int flags) =
 	(void *) BPF_FUNC_skb_change_head;
+static int (*bpf_skb_pull_data)(void *, int len) =
+	(void *) BPF_FUNC_skb_pull_data;
 
 /* Scan the ARCH passed in from ARCH env variable (see Makefile) */
 #if defined(__TARGET_ARCH_x86)

tools/testing/selftests/bpf/sockmap_parse_prog.c

···
 	__u32 lport = skb->local_port;
 	__u32 rport = skb->remote_port;
 	__u8 *d = data;
+	__u32 len = (__u32) data_end - (__u32) data;
+	int err;
 
-	if (data + 10 > data_end)
-		return skb->len;
+	if (data + 10 > data_end) {
+		err = bpf_skb_pull_data(skb, 10);
+		if (err)
+			return SK_DROP;
+
+		data_end = (void *)(long)skb->data_end;
+		data = (void *)(long)skb->data;
+		if (data + 10 > data_end)
+			return SK_DROP;
+	}
 
 	/* This write/read is a bit pointless but tests the verifier and
 	 * strparser handler for read/write pkt data and access into sk
 	 * fields.
 	 */
+	d = data;
 	d[7] = 1;
 	return skb->len;
 }

tools/testing/selftests/bpf/sockmap_tcp_msg_prog.c

···
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+#include "bpf_util.h"
+#include "bpf_endian.h"
+
+int _version SEC("version") = 1;
+
+#define bpf_printk(fmt, ...)					\
+({								\
+	       char ____fmt[] = fmt;				\
+	       bpf_trace_printk(____fmt, sizeof(____fmt),	\
+				##__VA_ARGS__);			\
+})
+
+SEC("sk_msg1")
+int bpf_prog1(struct sk_msg_md *msg)
+{
+	void *data_end = (void *)(long) msg->data_end;
+	void *data = (void *)(long) msg->data;
+
+	char *d;
+
+	if (data + 8 > data_end)
+		return SK_DROP;
+
+	bpf_printk("data length %i\n", (__u64)msg->data_end - (__u64)msg->data);
+	d = (char *)data;
+	bpf_printk("hello sendmsg hook %i %i\n", d[0], d[1]);
+
+	return SK_PASS;
+}
+
+char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/sockmap_verdict_prog.c

···
 	.max_entries = 20,
 };
 
+struct bpf_map_def SEC("maps") sock_map_msg = {
+	.type = BPF_MAP_TYPE_SOCKMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 20,
+};
+
 struct bpf_map_def SEC("maps") sock_map_break = {
 	.type = BPF_MAP_TYPE_ARRAY,
 	.key_size = sizeof(int),

tools/testing/selftests/bpf/test_maps.c

···
 #include <linux/err.h>
 #define SOCKMAP_PARSE_PROG "./sockmap_parse_prog.o"
 #define SOCKMAP_VERDICT_PROG "./sockmap_verdict_prog.o"
+#define SOCKMAP_TCP_MSG_PROG "./sockmap_tcp_msg_prog.o"
 static void test_sockmap(int tasks, void *data)
 {
-	int one = 1, map_fd_rx = 0, map_fd_tx = 0, map_fd_break, s, sc, rc;
-	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_break;
+	struct bpf_map *bpf_map_rx, *bpf_map_tx, *bpf_map_msg, *bpf_map_break;
+	int map_fd_msg = 0, map_fd_rx = 0, map_fd_tx = 0, map_fd_break;
 	int ports[] = {50200, 50201, 50202, 50204};
 	int err, i, fd, udp, sfd[6] = {0xdeadbeef};
 	u8 buf[20] = {0x0, 0x5, 0x3, 0x2, 0x1, 0x0};
-	int parse_prog, verdict_prog;
+	int parse_prog, verdict_prog, msg_prog;
 	struct sockaddr_in addr;
+	int one = 1, s, sc, rc;
 	struct bpf_object *obj;
 	struct timeval to;
 	__u32 key, value;
···
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_attach(-1, fd, BPF_SK_MSG_VERDICT, 0);
+	if (!err) {
+		printf("Failed invalid msg verdict prog attach\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_attach(-1, fd, __MAX_BPF_ATTACH_TYPE, 0);
 	if (!err) {
 		printf("Failed unknown prog attach\n");
···
 		goto out_sockmap;
 	}
 
+	err = bpf_prog_detach(fd, BPF_SK_MSG_VERDICT);
+	if (err) {
+		printf("Failed empty msg verdict prog detach\n");
+		goto out_sockmap;
+	}
+
 	err = bpf_prog_detach(fd, __MAX_BPF_ATTACH_TYPE);
 	if (!err) {
 		printf("Detach invalid prog successful\n");
···
 			    BPF_PROG_TYPE_SK_SKB, &obj, &parse_prog);
 	if (err) {
 		printf("Failed to load SK_SKB parse prog\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_load(SOCKMAP_TCP_MSG_PROG,
+			    BPF_PROG_TYPE_SK_MSG, &obj, &msg_prog);
+	if (err) {
+		printf("Failed to load SK_SKB msg prog\n");
 		goto out_sockmap;
 	}
 
···
 
 	map_fd_rx = bpf_map__fd(bpf_map_rx);
 	if (map_fd_rx < 0) {
-		printf("Failed to get map fd\n");
+		printf("Failed to get map rx fd\n");
 		goto out_sockmap;
 	}
 
···
 	map_fd_tx = bpf_map__fd(bpf_map_tx);
 	if (map_fd_tx < 0) {
 		printf("Failed to get map tx fd\n");
+		goto out_sockmap;
+	}
+
+	bpf_map_msg = bpf_object__find_map_by_name(obj, "sock_map_msg");
+	if (IS_ERR(bpf_map_msg)) {
+		printf("Failed to load map msg from msg_verdict prog\n");
+		goto out_sockmap;
+	}
+
+	map_fd_msg = bpf_map__fd(bpf_map_msg);
+	if (map_fd_msg < 0) {
+		printf("Failed to get map msg fd\n");
 		goto out_sockmap;
 	}
 
···
 			      BPF_SK_SKB_STREAM_VERDICT, 0);
 	if (err) {
 		printf("Failed stream verdict bpf prog attach\n");
+		goto out_sockmap;
+	}
+
+	err = bpf_prog_attach(msg_prog, map_fd_msg, BPF_SK_MSG_VERDICT, 0);
+	if (err) {
+		printf("Failed msg verdict bpf prog attach\n");
 		goto out_sockmap;
 	}
 
···
 			       err, i, sfd[i]);
 			goto out_sockmap;
 		}
+	}
+
+	/* Put sfd[2] (sending fd below) into msg map to test sendmsg bpf */
+	i = 0;
+	err = bpf_map_update_elem(map_fd_msg, &i, &sfd[2], BPF_ANY);
+	if (err) {
+		printf("Failed map_fd_msg update sockmap %i\n", err);
+		goto out_sockmap;
 	}
 
 	/* Test map send/recv */