bpf: sockmap sample, add option to attach SK_MSG program

Add sockmap option to use SK_MSG program types.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

samples/bpf/bpf_load.c

@@ -67,6 +67,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 	bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
 	bool is_sockops = strncmp(event, "sockops", 7) == 0;
 	bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0;
+	bool is_sk_msg = strncmp(event, "sk_msg", 6) == 0;
 	size_t insns_cnt = size / sizeof(struct bpf_insn);
 	enum bpf_prog_type prog_type;
 	char buf[256];
@@ -96,6 +97,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 		prog_type = BPF_PROG_TYPE_SOCK_OPS;
 	} else if (is_sk_skb) {
 		prog_type = BPF_PROG_TYPE_SK_SKB;
+	} else if (is_sk_msg) {
+		prog_type = BPF_PROG_TYPE_SK_MSG;
 	} else {
 		printf("Unknown event '%s'\n", event);
 		return -1;
@@ -113,7 +116,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
 	if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
 		return 0;
 
-	if (is_socket || is_sockops || is_sk_skb) {
+	if (is_socket || is_sockops || is_sk_skb || is_sk_msg) {
 		if (is_socket)
 			event += 6;
 		else
@@ -589,7 +592,8 @@ static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
 		    memcmp(shname, "socket", 6) == 0 ||
 		    memcmp(shname, "cgroup/", 7) == 0 ||
 		    memcmp(shname, "sockops", 7) == 0 ||
-		    memcmp(shname, "sk_skb", 6) == 0) {
+		    memcmp(shname, "sk_skb", 6) == 0 ||
+		    memcmp(shname, "sk_msg", 6) == 0) {
 			ret = load_and_attach(shname, data->d_buf,
 					      data->d_size);
 			if (ret != 0)

samples/sockmap/sockmap_kern.c

@@ -43,6 +43,20 @@ struct bpf_map_def SEC("maps") sock_map = {
 	.max_entries = 20,
 };
 
+struct bpf_map_def SEC("maps") sock_map_txmsg = {
+	.type = BPF_MAP_TYPE_SOCKMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 20,
+};
+
+struct bpf_map_def SEC("maps") sock_map_redir = {
+	.type = BPF_MAP_TYPE_SOCKMAP,
+	.key_size = sizeof(int),
+	.value_size = sizeof(int),
+	.max_entries = 1,
+};
+
 SEC("sk_skb1")
 int bpf_prog1(struct __sk_buff *skb)
 {
@@ -105,4 +119,42 @@ int bpf_sockmap(struct bpf_sock_ops *skops)
 
 	return 0;
 }
+
+SEC("sk_msg1")
+int bpf_prog4(struct sk_msg_md *msg)
+{
+	return SK_PASS;
+}
+
+SEC("sk_msg2")
+int bpf_prog5(struct sk_msg_md *msg)
+{
+	void *data_end = (void *)(long) msg->data_end;
+	void *data = (void *)(long) msg->data;
+
+	bpf_printk("sk_msg2: data length %i\n", (__u32)data_end - (__u32)data);
+	return SK_PASS;
+}
+
+SEC("sk_msg3")
+int bpf_prog6(struct sk_msg_md *msg)
+{
+	void *data_end = (void *)(long) msg->data_end;
+	void *data = (void *)(long) msg->data;
+	int ret = 0;
+
+	return bpf_msg_redirect_map(msg, &sock_map_redir, ret, 0);
+}
+
+SEC("sk_msg4")
+int bpf_prog7(struct sk_msg_md *msg)
+{
+	void *data_end = (void *)(long) msg->data_end;
+	void *data = (void *)(long) msg->data;
+	int ret = 0;
+
+	bpf_printk("sk_msg3: redirect(%iB)\n", (__u32)data_end - (__u32)data);
+	return bpf_msg_redirect_map(msg, &sock_map_redir, ret, 0);
+}
+
 char _license[] SEC("license") = "GPL";

samples/sockmap/sockmap_user.c

@@ -54,6 +54,11 @@ void running_handler(int a);
 /* global sockets */
 int s1, s2, c1, c2, p1, p2;
 
+int txmsg_pass;
+int txmsg_noisy;
+int txmsg_redir;
+int txmsg_redir_noisy;
+
 static const struct option long_options[] = {
 	{"help",	no_argument,		NULL, 'h' },
 	{"cgroup",	required_argument,	NULL, 'c' },
@@ -62,6 +67,10 @@ static const struct option long_options[] = {
 	{"iov_count",	required_argument,	NULL, 'i' },
 	{"length",	required_argument,	NULL, 'l' },
 	{"test",	required_argument,	NULL, 't' },
+	{"txmsg",		no_argument,		&txmsg_pass,  1  },
+	{"txmsg_noisy",		no_argument,		&txmsg_noisy, 1  },
+	{"txmsg_redir",		no_argument,		&txmsg_redir, 1  },
+	{"txmsg_redir_noisy",	no_argument,		&txmsg_redir_noisy, 1},
 	{0, 0, NULL, 0 }
 };
 
@@ -447,13 +456,13 @@ enum {
 
 int main(int argc, char **argv)
 {
-	int iov_count = 1, length = 1024, rate = 1, verbose = 0;
+	int iov_count = 1, length = 1024, rate = 1, verbose = 0, tx_prog_fd;
 	struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY};
 	int opt, longindex, err, cg_fd = 0;
 	int test = PING_PONG;
 	char filename[256];
 
-	while ((opt = getopt_long(argc, argv, "hvc:r:i:l:t:",
+	while ((opt = getopt_long(argc, argv, ":hvc:r:i:l:t:",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		/* Cgroup configuration */
@@ -490,6 +499,8 @@ int main(int argc, char **argv)
 				return -1;
 			}
 			break;
+		case 0:
+			break;
 		case 'h':
 		default:
 			usage(argv);
@@ -515,16 +526,16 @@ int main(int argc, char **argv)
 	/* catch SIGINT */
 	signal(SIGINT, running_handler);
 
-	/* If base test skip BPF setup */
-	if (test == BASE)
-		goto run;
-
 	if (load_bpf_file(filename)) {
 		fprintf(stderr, "load_bpf_file: (%s) %s\n",
 			filename, strerror(errno));
 		return 1;
 	}
 
+	/* If base test skip BPF setup */
+	if (test == BASE)
+		goto run;
+
 	/* Attach programs to sockmap */
 	err = bpf_prog_attach(prog_fd[0], map_fd[0],
 				BPF_SK_SKB_STREAM_PARSER, 0);
@@ -557,6 +568,50 @@ int main(int argc, char **argv)
 		goto out;
 	}
 
+	/* Attach txmsg program to sockmap */
+	if (txmsg_pass)
+		tx_prog_fd = prog_fd[3];
+	else if (txmsg_noisy)
+		tx_prog_fd = prog_fd[4];
+	else if (txmsg_redir)
+		tx_prog_fd = prog_fd[5];
+	else if (txmsg_redir_noisy)
+		tx_prog_fd = prog_fd[6];
+	else
+		tx_prog_fd = 0;
+
+	if (tx_prog_fd) {
+		int redir_fd, i = 0;
+
+		err = bpf_prog_attach(tx_prog_fd,
+				      map_fd[1], BPF_SK_MSG_VERDICT, 0);
+		if (err) {
+			fprintf(stderr,
+				"ERROR: bpf_prog_attach (txmsg): %d (%s)\n",
+				err, strerror(errno));
+			return err;
+		}
+
+		err = bpf_map_update_elem(map_fd[1], &i, &c1, BPF_ANY);
+		if (err) {
+			fprintf(stderr,
+				"ERROR: bpf_map_update_elem (txmsg):  %d (%s\n",
+				err, strerror(errno));
+			return err;
+		}
+		if (test == SENDMSG)
+			redir_fd = c2;
+		else
+			redir_fd = c1;
+
+		err = bpf_map_update_elem(map_fd[2], &i, &redir_fd, BPF_ANY);
+		if (err) {
+			fprintf(stderr,
+				"ERROR: bpf_map_update_elem (txmsg):  %d (%s\n",
+				err, strerror(errno));
+			return err;
+		}
+	}
 	if (test == PING_PONG)
 		err = forever_ping_pong(rate, verbose);
 	else if (test == SENDMSG)

tools/include/uapi/linux/bpf.h

@@ -720,6 +720,15 @@ union bpf_attr {
  * int bpf_override_return(pt_regs, rc)
  *	@pt_regs: pointer to struct pt_regs
  *	@rc: the return value to set
+ *
+ * int bpf_msg_redirect_map(map, key, flags)
+ *     Redirect msg to a sock in map using key as a lookup key for the
+ *     sock in map.
+ *     @map: pointer to sockmap
+ *     @key: key to lookup sock in map
+ *     @flags: reserved for future use
+ *     Return: SK_PASS
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -781,7 +790,9 @@ union bpf_attr {
 	FN(perf_prog_read_value),	\
 	FN(getsockopt),			\
 	FN(override_return),		\
-	FN(sock_ops_cb_flags_set),
+	FN(sock_ops_cb_flags_set),	\
+	FN(msg_redirect_map),		\
+	FN(msg_apply_bytes),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

tools/lib/bpf/libbpf.c

@@ -1857,6 +1857,7 @@ static const struct {
 	BPF_PROG_SEC("lwt_xmit",	BPF_PROG_TYPE_LWT_XMIT),
 	BPF_PROG_SEC("sockops",		BPF_PROG_TYPE_SOCK_OPS),
 	BPF_PROG_SEC("sk_skb",		BPF_PROG_TYPE_SK_SKB),
+	BPF_PROG_SEC("sk_msg",		BPF_PROG_TYPE_SK_MSG),
 };
 #undef BPF_PROG_SEC
 

tools/testing/selftests/bpf/bpf_helpers.h

@@ -86,6 +86,9 @@ static int (*bpf_perf_prog_read_value)(void *ctx, void *buf,
 	(void *) BPF_FUNC_perf_prog_read_value;
 static int (*bpf_override_return)(void *ctx, unsigned long rc) =
 	(void *) BPF_FUNC_override_return;
+static int (*bpf_msg_redirect_map)(void *ctx, void *map, int key, int flags) =
+	(void *) BPF_FUNC_msg_redirect_map;
+
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions