[bpf-next,7/8] bpf: tcp: Support bpf_setsockopt in bpf tcp iter

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f309fc1509f2..31f51a601925 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1397,6 +1397,9 @@  typedef void (*bpf_iter_show_fdinfo_t) (const struct bpf_iter_aux_info *aux,
 					struct seq_file *seq);
 typedef int (*bpf_iter_fill_link_info_t)(const struct bpf_iter_aux_info *aux,
 					 struct bpf_link_info *info);
+typedef const struct bpf_func_proto *
+(*bpf_iter_get_func_proto_t)(enum bpf_func_id func_id,
+			     const struct bpf_prog *prog);
 
 enum bpf_iter_feature {
 	BPF_ITER_RESCHED	= BIT(0),
@@ -1409,6 +1412,7 @@  struct bpf_iter_reg {
 	bpf_iter_detach_target_t detach_target;
 	bpf_iter_show_fdinfo_t show_fdinfo;
 	bpf_iter_fill_link_info_t fill_link_info;
+	bpf_iter_get_func_proto_t get_func_proto;
 	u32 ctx_arg_info_size;
 	u32 feature;
 	struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX];
@@ -1431,6 +1435,8 @@  struct bpf_iter__bpf_map_elem {
 int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info);
 void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info);
 bool bpf_iter_prog_supported(struct bpf_prog *prog);
+const struct bpf_func_proto *
+bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);
 int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_prog *prog);
 int bpf_iter_new_fd(struct bpf_link *link);
 bool bpf_link_is_iter(struct bpf_link *link);
@@ -1997,6 +2003,7 @@  extern const struct bpf_func_proto bpf_task_storage_get_proto;
 extern const struct bpf_func_proto bpf_task_storage_delete_proto;
 extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
 extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
+extern const struct bpf_func_proto bpf_sk_setsockopt_proto;
 
 const struct bpf_func_proto *bpf_tracing_func_proto(
 	enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 2d4fbdbb194e..2e9d47bb40ff 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -360,6 +360,28 @@  bool bpf_iter_prog_supported(struct bpf_prog *prog)
 	return supported;
 }
 
+const struct bpf_func_proto *
+bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	const struct bpf_iter_target_info *tinfo;
+	const struct bpf_func_proto *fn = NULL;
+
+	mutex_lock(&targets_mutex);
+	list_for_each_entry(tinfo, &targets, list) {
+		if (tinfo->btf_id == prog->aux->attach_btf_id) {
+			const struct bpf_iter_reg *reg_info;
+
+			reg_info = tinfo->reg_info;
+			if (reg_info->get_func_proto)
+				fn = reg_info->get_func_proto(func_id, prog);
+			break;
+		}
+	}
+	mutex_unlock(&targets_mutex);
+
+	return fn;
+}
+
 static void bpf_iter_link_release(struct bpf_link *link)
 {
 	struct bpf_iter_link *iter_link =
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 7a52bc172841..11e69734d67b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1428,6 +1428,8 @@  raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 const struct bpf_func_proto *
 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
+	const struct bpf_func_proto *fn;
+
 	switch (func_id) {
 #ifdef CONFIG_NET
 	case BPF_FUNC_skb_output:
@@ -1468,7 +1470,10 @@  tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_d_path:
 		return &bpf_d_path_proto;
 	default:
-		return raw_tp_prog_func_proto(func_id, prog);
+		fn = raw_tp_prog_func_proto(func_id, prog);
+		if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
+			fn = bpf_iter_get_func_proto(func_id, prog);
+		return fn;
 	}
 }
 
diff --git a/net/core/filter.c b/net/core/filter.c
index d22895caa164..ab4d60c043d4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5063,6 +5063,23 @@  static const struct bpf_func_proto bpf_sock_ops_setsockopt_proto = {
 	.arg5_type	= ARG_CONST_SIZE,
 };
 
+BPF_CALL_5(bpf_sk_setsockopt, struct sock *, sk, int, level,
+	   int, optname, char *, optval, int, optlen)
+{
+	return _bpf_setsockopt(sk, level, optname, optval, optlen);
+}
+
+const struct bpf_func_proto bpf_sk_setsockopt_proto = {
+	.func		= bpf_sk_setsockopt,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_ANYTHING,
+	.arg4_type	= ARG_PTR_TO_MEM,
+	.arg5_type	= ARG_CONST_SIZE,
+};
+
 static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock,
 				int optname, const u8 **start)
 {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 856144d33f52..5bfa6233fff1 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -3258,6 +3258,20 @@  static const struct bpf_iter_seq_info tcp_seq_info = {
 	.seq_priv_size		= sizeof(struct bpf_tcp_iter_state),
 };
 
+static const struct bpf_func_proto *
+bpf_iter_tcp_get_func_proto(enum bpf_func_id func_id,
+			    const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_setsockopt:
+		if (capable(CAP_NET_ADMIN))
+			return &bpf_sk_setsockopt_proto;
+		fallthrough;
+	default:
+		return NULL;
+	}
+}
+
 static struct bpf_iter_reg tcp_reg_info = {
 	.target			= "tcp",
 	.ctx_arg_info_size	= 1,
@@ -3265,6 +3279,7 @@  static struct bpf_iter_reg tcp_reg_info = {
 		{ offsetof(struct bpf_iter__tcp, sk_common),
 		  PTR_TO_BTF_ID_OR_NULL },
 	},
+	.get_func_proto		= bpf_iter_tcp_get_func_proto,
 	.seq_info		= &tcp_seq_info,
 };