bpf: Refactor bpf_iter_reg to have separate seq_info member

There is no functionality change for this patch.
Struct bpf_iter_reg is used to register a bpf_iter target,
which includes information for both prog_load, link_create
and seq_file creation.

This patch puts fields related seq_file creation into
a different structure. This will be useful for map
elements iterator where one iterator covers different
map types and different map types may have different
seq_ops, init/fini private_data function and
private_data size.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com

4 files changed, 24 insertions, 8 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f8913923a6c0..cb288fdcf2ca 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2947,17 +2947,21 @@ static void bpf_iter_fini_tcp(void *priv_data)
 	bpf_iter_fini_seq_net(priv_data);
 }
 
-static struct bpf_iter_reg tcp_reg_info = {
-	.target			= "tcp",
+static const struct bpf_iter_seq_info tcp_seq_info = {
 	.seq_ops		= &bpf_iter_tcp_seq_ops,
 	.init_seq_private	= bpf_iter_init_tcp,
 	.fini_seq_private	= bpf_iter_fini_tcp,
 	.seq_priv_size		= sizeof(struct tcp_iter_state),
+};
+
+static struct bpf_iter_reg tcp_reg_info = {
+	.target			= "tcp",
 	.ctx_arg_info_size	= 1,
 	.ctx_arg_info		= {
 		{ offsetof(struct bpf_iter__tcp, sk_common),
 		  PTR_TO_BTF_ID_OR_NULL },
 	},
+	.seq_info		= &tcp_seq_info,
 };
 
 static void __init bpf_iter_register(void)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 0fb5e4ea133f..1bc50ec2caef 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -3208,17 +3208,21 @@ static void bpf_iter_fini_udp(void *priv_data)
 	bpf_iter_fini_seq_net(priv_data);
 }
 
-static struct bpf_iter_reg udp_reg_info = {
-	.target			= "udp",
+static const struct bpf_iter_seq_info udp_seq_info = {
 	.seq_ops		= &bpf_iter_udp_seq_ops,
 	.init_seq_private	= bpf_iter_init_udp,
 	.fini_seq_private	= bpf_iter_fini_udp,
 	.seq_priv_size		= sizeof(struct udp_iter_state),
+};
+
+static struct bpf_iter_reg udp_reg_info = {
+	.target			= "udp",
 	.ctx_arg_info_size	= 1,
 	.ctx_arg_info		= {
 		{ offsetof(struct bpf_iter__udp, udp_sk),
 		  PTR_TO_BTF_ID_OR_NULL },
 	},
+	.seq_info		= &udp_seq_info,
 };
 
 static void __init bpf_iter_register(void)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 33f5efbad0a9..8bfc57b0802a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -6427,17 +6427,21 @@ DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *r
 BTF_ID_LIST(btf_fib6_info_id)
 BTF_ID(struct, fib6_info)
 
-static struct bpf_iter_reg ipv6_route_reg_info = {
-	.target			= "ipv6_route",
+static const struct bpf_iter_seq_info ipv6_route_seq_info = {
 	.seq_ops		= &ipv6_route_seq_ops,
 	.init_seq_private	= bpf_iter_init_seq_net,
 	.fini_seq_private	= bpf_iter_fini_seq_net,
 	.seq_priv_size		= sizeof(struct ipv6_route_iter),
+};
+
+static struct bpf_iter_reg ipv6_route_reg_info = {
+	.target			= "ipv6_route",
 	.ctx_arg_info_size	= 1,
 	.ctx_arg_info		= {
 		{ offsetof(struct bpf_iter__ipv6_route, rt),
 		  PTR_TO_BTF_ID_OR_NULL },
 	},
+	.seq_info		= &ipv6_route_seq_info,
 };
 
 static int __init bpf_iter_register(void)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d8921b833744..b5f30d7d30d0 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2807,17 +2807,21 @@ static const struct rhashtable_params netlink_rhashtable_params = {
 BTF_ID_LIST(btf_netlink_sock_id)
 BTF_ID(struct, netlink_sock)
 
-static struct bpf_iter_reg netlink_reg_info = {
-	.target			= "netlink",
+static const struct bpf_iter_seq_info netlink_seq_info = {
 	.seq_ops		= &netlink_seq_ops,
 	.init_seq_private	= bpf_iter_init_seq_net,
 	.fini_seq_private	= bpf_iter_fini_seq_net,
 	.seq_priv_size		= sizeof(struct nl_seq_iter),
+};
+
+static struct bpf_iter_reg netlink_reg_info = {
+	.target			= "netlink",
 	.ctx_arg_info_size	= 1,
 	.ctx_arg_info		= {
 		{ offsetof(struct bpf_iter__netlink, sk),
 		  PTR_TO_BTF_ID_OR_NULL },
 	},
+	.seq_info		= &netlink_seq_info,
 };
 
 static int __init bpf_iter_register(void)