bpf: Clean up sockmap related Kconfigs

As suggested by John, clean up sockmap related Kconfigs:

Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream
parser, to reflect its name.

Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL
and CONFIG_INET, the latter is still needed at this point because
of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched,
as it is used by non-sockmap cases.
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Lorenz Bauer <lmb@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com

include/linux/bpf.h

@@ -1778,7 +1778,7 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map)
 }
 #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */
 
-#if defined(CONFIG_BPF_STREAM_PARSER)
+#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)
 int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
 			 struct bpf_prog *old, u32 which);
 int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog);
@@ -1786,7 +1786,18 @@ int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype);
 int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags);
 void sock_map_unhash(struct sock *sk);
 void sock_map_close(struct sock *sk, long timeout);
+
+void bpf_sk_reuseport_detach(struct sock *sk);
+int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key,
+				       void *value);
+int bpf_fd_reuseport_array_update_elem(struct bpf_map *map, void *key,
+				       void *value, u64 map_flags);
 #else
+static inline void bpf_sk_reuseport_detach(struct sock *sk)
+{
+}
+
+#ifdef CONFIG_BPF_SYSCALL
 static inline int sock_map_prog_update(struct bpf_map *map,
 				       struct bpf_prog *prog,
 				       struct bpf_prog *old, u32 which)
@@ -1811,20 +1822,7 @@ static inline int sock_map_update_elem_sys(struct bpf_map *map, void *key, void
 {
 	return -EOPNOTSUPP;
 }
-#endif /* CONFIG_BPF_STREAM_PARSER */
 
-#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)
-void bpf_sk_reuseport_detach(struct sock *sk);
-int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key,
-				       void *value);
-int bpf_fd_reuseport_array_update_elem(struct bpf_map *map, void *key,
-				       void *value, u64 map_flags);
-#else
-static inline void bpf_sk_reuseport_detach(struct sock *sk)
-{
-}
-
-#ifdef CONFIG_BPF_SYSCALL
 static inline int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map,
 						     void *key, void *value)
 {

include/linux/bpf_types.h

@@ -103,10 +103,6 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP_HASH, dev_map_hash_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_SK_STORAGE, sk_storage_map_ops)
-#if defined(CONFIG_BPF_STREAM_PARSER)
-BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
-BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops)
-#endif
 #ifdef CONFIG_BPF_LSM
 BPF_MAP_TYPE(BPF_MAP_TYPE_INODE_STORAGE, inode_storage_map_ops)
 #endif
@@ -116,6 +112,8 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_CPUMAP, cpu_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops)
 #endif
 #ifdef CONFIG_INET
+BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
+BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops)
 #endif
 #endif

include/linux/skmsg.h

@@ -71,7 +71,9 @@ struct sk_psock_link {
 };
 
 struct sk_psock_parser {
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
 	struct strparser		strp;
+#endif
 	bool				enabled;
 	void (*saved_data_ready)(struct sock *sk);
 };
@@ -305,9 +307,25 @@ static inline void sk_psock_report_error(struct sk_psock *psock, int err)
 
 struct sk_psock *sk_psock_init(struct sock *sk, int node);
 
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
 int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
 void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
 void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
+#else
+static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
+{
+}
+
+static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
+{
+}
+#endif
+
 void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
 void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
 

include/net/tcp.h

@@ -2222,25 +2222,27 @@ void tcp_update_ulp(struct sock *sk, struct proto *p,
 	__MODULE_INFO(alias, alias_userspace, name);		\
 	__MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name)
 
+#ifdef CONFIG_NET_SOCK_MSG
 struct sk_msg;
 struct sk_psock;
 
-#ifdef CONFIG_BPF_STREAM_PARSER
+#ifdef CONFIG_BPF_SYSCALL
 struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock);
 void tcp_bpf_clone(const struct sock *sk, struct sock *newsk);
-#else
-static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
-{
-}
-#endif /* CONFIG_BPF_STREAM_PARSER */
+#endif /* CONFIG_BPF_SYSCALL */
 
-#ifdef CONFIG_NET_SOCK_MSG
 int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, u32 bytes,
 			  int flags);
 int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
 		      struct msghdr *msg, int len, int flags);
 #endif /* CONFIG_NET_SOCK_MSG */
 
+#if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG)
+static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
+{
+}
+#endif
+
 #ifdef CONFIG_CGROUP_BPF
 static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops,
 				      struct sk_buff *skb,

include/net/udp.h

@@ -515,9 +515,9 @@ static inline struct sk_buff *udp_rcv_segment(struct sock *sk,
 	return segs;
 }
 
-#ifdef CONFIG_BPF_STREAM_PARSER
+#ifdef CONFIG_BPF_SYSCALL
 struct sk_psock;
 struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock);
-#endif /* BPF_STREAM_PARSER */
+#endif
 
 #endif	/* _UDP_H */

init/Kconfig

@@ -1702,6 +1702,7 @@ config BPF_SYSCALL
 	select BPF
 	select IRQ_WORK
 	select TASKS_TRACE_RCU
+	select NET_SOCK_MSG if INET
 	default n
 	help
 	  Enable the bpf() system call that allows to manipulate eBPF

net/Kconfig

@@ -317,13 +317,9 @@ config BPF_STREAM_PARSER
 	select STREAM_PARSER
 	select NET_SOCK_MSG
 	help
-	  Enabling this allows a stream parser to be used with
+	  Enabling this allows a TCP stream parser to be used with
 	  BPF_MAP_TYPE_SOCKMAP.
 
-	  BPF_MAP_TYPE_SOCKMAP provides a map type to use with network sockets.
-	  It can be used to enforce socket policy, implement socket redirects,
-	  etc.
-
 config NET_FLOW_LIMIT
 	bool
 	depends on RPS

net/core/Makefile

@@ -16,7 +16,6 @@ obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
 obj-y += net-sysfs.o
 obj-$(CONFIG_PAGE_POOL) += page_pool.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
-obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o
 obj-$(CONFIG_NET_PKTGEN) += pktgen.o
 obj-$(CONFIG_NETPOLL) += netpoll.o
 obj-$(CONFIG_FIB_RULES) += fib_rules.o
@@ -28,10 +27,13 @@ obj-$(CONFIG_CGROUP_NET_PRIO) += netprio_cgroup.o
 obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o
 obj-$(CONFIG_LWTUNNEL) += lwtunnel.o
 obj-$(CONFIG_LWTUNNEL_BPF) += lwt_bpf.o
-obj-$(CONFIG_BPF_STREAM_PARSER) += sock_map.o
 obj-$(CONFIG_DST_CACHE) += dst_cache.o
 obj-$(CONFIG_HWBM) += hwbm.o
 obj-$(CONFIG_NET_DEVLINK) += devlink.o
 obj-$(CONFIG_GRO_CELLS) += gro_cells.o
 obj-$(CONFIG_FAILOVER) += failover.o
+ifeq ($(CONFIG_INET),y)
+obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o
+obj-$(CONFIG_BPF_SYSCALL) += sock_map.o
+endif
 obj-$(CONFIG_BPF_SYSCALL) += bpf_sk_storage.o

net/core/skmsg.c

@@ -645,15 +645,15 @@ static void sk_psock_link_destroy(struct sk_psock *psock)
 	}
 }
 
+static void sk_psock_done_strp(struct sk_psock *psock);
+
 static void sk_psock_destroy_deferred(struct work_struct *gc)
 {
 	struct sk_psock *psock = container_of(gc, struct sk_psock, gc);
 
 	/* No sk_callback_lock since already detached. */
 
-	/* Parser has been stopped */
-	if (psock->progs.skb_parser)
-		strp_done(&psock->parser.strp);
+	sk_psock_done_strp(psock);
 
 	cancel_work_sync(&psock->work);
 
@@ -750,14 +750,6 @@ static int sk_psock_bpf_run(struct sk_psock *psock, struct bpf_prog *prog,
 	return bpf_prog_run_pin_on_cpu(prog, skb);
 }
 
-static struct sk_psock *sk_psock_from_strp(struct strparser *strp)
-{
-	struct sk_psock_parser *parser;
-
-	parser = container_of(strp, struct sk_psock_parser, strp);
-	return container_of(parser, struct sk_psock, parser);
-}
-
 static void sk_psock_skb_redirect(struct sk_buff *skb)
 {
 	struct sk_psock *psock_other;
@@ -866,6 +858,24 @@ static void sk_psock_verdict_apply(struct sk_psock *psock,
 	}
 }
 
+static void sk_psock_write_space(struct sock *sk)
+{
+	struct sk_psock *psock;
+	void (*write_space)(struct sock *sk) = NULL;
+
+	rcu_read_lock();
+	psock = sk_psock(sk);
+	if (likely(psock)) {
+		if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
+			schedule_work(&psock->work);
+		write_space = psock->saved_write_space;
+	}
+	rcu_read_unlock();
+	if (write_space)
+		write_space(sk);
+}
+
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
 static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)
 {
 	struct sk_psock *psock;
@@ -897,6 +907,14 @@ static int sk_psock_strp_read_done(struct strparser *strp, int err)
 	return err;
 }
 
+static struct sk_psock *sk_psock_from_strp(struct strparser *strp)
+{
+	struct sk_psock_parser *parser;
+
+	parser = container_of(strp, struct sk_psock_parser, strp);
+	return container_of(parser, struct sk_psock, parser);
+}
+
 static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)
 {
 	struct sk_psock *psock = sk_psock_from_strp(strp);
@@ -933,6 +951,56 @@ static void sk_psock_strp_data_ready(struct sock *sk)
 	rcu_read_unlock();
 }
 
+int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
+{
+	static const struct strp_callbacks cb = {
+		.rcv_msg	= sk_psock_strp_read,
+		.read_sock_done	= sk_psock_strp_read_done,
+		.parse_msg	= sk_psock_strp_parse,
+	};
+
+	psock->parser.enabled = false;
+	return strp_init(&psock->parser.strp, sk, &cb);
+}
+
+void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
+{
+	struct sk_psock_parser *parser = &psock->parser;
+
+	if (parser->enabled)
+		return;
+
+	parser->saved_data_ready = sk->sk_data_ready;
+	sk->sk_data_ready = sk_psock_strp_data_ready;
+	sk->sk_write_space = sk_psock_write_space;
+	parser->enabled = true;
+}
+
+void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
+{
+	struct sk_psock_parser *parser = &psock->parser;
+
+	if (!parser->enabled)
+		return;
+
+	sk->sk_data_ready = parser->saved_data_ready;
+	parser->saved_data_ready = NULL;
+	strp_stop(&parser->strp);
+	parser->enabled = false;
+}
+
+static void sk_psock_done_strp(struct sk_psock *psock)
+{
+	/* Parser has been stopped */
+	if (psock->progs.skb_parser)
+		strp_done(&psock->parser.strp);
+}
+#else
+static void sk_psock_done_strp(struct sk_psock *psock)
+{
+}
+#endif /* CONFIG_BPF_STREAM_PARSER */
+
 static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb,
 				 unsigned int offset, size_t orig_len)
 {
@@ -984,35 +1052,6 @@ static void sk_psock_verdict_data_ready(struct sock *sk)
 	sock->ops->read_sock(sk, &desc, sk_psock_verdict_recv);
 }
 
-static void sk_psock_write_space(struct sock *sk)
-{
-	struct sk_psock *psock;
-	void (*write_space)(struct sock *sk) = NULL;
-
-	rcu_read_lock();
-	psock = sk_psock(sk);
-	if (likely(psock)) {
-		if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
-			schedule_work(&psock->work);
-		write_space = psock->saved_write_space;
-	}
-	rcu_read_unlock();
-	if (write_space)
-		write_space(sk);
-}
-
-int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
-{
-	static const struct strp_callbacks cb = {
-		.rcv_msg	= sk_psock_strp_read,
-		.read_sock_done	= sk_psock_strp_read_done,
-		.parse_msg	= sk_psock_strp_parse,
-	};
-
-	psock->parser.enabled = false;
-	return strp_init(&psock->parser.strp, sk, &cb);
-}
-
 void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
 {
 	struct sk_psock_parser *parser = &psock->parser;
@@ -1026,32 +1065,6 @@ void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
 	parser->enabled = true;
 }
 
-void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
-{
-	struct sk_psock_parser *parser = &psock->parser;
-
-	if (parser->enabled)
-		return;
-
-	parser->saved_data_ready = sk->sk_data_ready;
-	sk->sk_data_ready = sk_psock_strp_data_ready;
-	sk->sk_write_space = sk_psock_write_space;
-	parser->enabled = true;
-}
-
-void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
-{
-	struct sk_psock_parser *parser = &psock->parser;
-
-	if (!parser->enabled)
-		return;
-
-	sk->sk_data_ready = parser->saved_data_ready;
-	parser->saved_data_ready = NULL;
-	strp_stop(&parser->strp);
-	parser->enabled = false;
-}
-
 void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock)
 {
 	struct sk_psock_parser *parser = &psock->parser;

net/core/sock_map.c

@@ -1461,9 +1461,11 @@ int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
 	case BPF_SK_MSG_VERDICT:
 		pprog = &progs->msg_parser;
 		break;
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
 	case BPF_SK_SKB_STREAM_PARSER:
 		pprog = &progs->skb_parser;
 		break;
+#endif
 	case BPF_SK_SKB_STREAM_VERDICT:
 		pprog = &progs->skb_verdict;
 		break;

net/ipv4/Makefile

@@ -62,7 +62,7 @@ obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
 obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
 obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
 obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o
-obj-$(CONFIG_BPF_STREAM_PARSER) += udp_bpf.o
+obj-$(CONFIG_BPF_SYSCALL) += udp_bpf.o
 obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
 
 obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \

net/ipv4/tcp_bpf.c

@@ -229,7 +229,7 @@ int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
 }
 EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);
 
-#ifdef CONFIG_BPF_STREAM_PARSER
+#ifdef CONFIG_BPF_SYSCALL
 static bool tcp_bpf_stream_read(const struct sock *sk)
 {
 	struct sk_psock *psock;
@@ -629,4 +629,4 @@ void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
 	if (prot == &tcp_bpf_prots[family][TCP_BPF_BASE])
 		newsk->sk_prot = sk->sk_prot_creator;
 }
-#endif /* CONFIG_BPF_STREAM_PARSER */
+#endif /* CONFIG_BPF_SYSCALL */