bpf: udp: Use bpf_udp_iter_batch_item for bpf_udp_iter_state batch items

Prepare for the next patch that tracks cookies between iterations by
converting struct sock **batch to union bpf_udp_iter_batch_item *batch
inside struct bpf_udp_iter_state.

Signed-off-by: Jordan Rife <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>

Author: jrife

net/ipv4/udp.c

@@ -3391,13 +3391,17 @@ struct bpf_iter__udp {
 	int bucket __aligned(8);
 };
 
+union bpf_udp_iter_batch_item {
+	struct sock *sock;
+};
+
 struct bpf_udp_iter_state {
 	struct udp_iter_state state;
 	unsigned int cur_sk;
 	unsigned int end_sk;
 	unsigned int max_sk;
 	int offset;
-	struct sock **batch;
+	union bpf_udp_iter_batch_item *batch;
 	bool st_bucket_done;
 };
 
@@ -3460,7 +3464,7 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
 				}
 				if (iter->end_sk < iter->max_sk) {
 					sock_hold(sk);
-					iter->batch[iter->end_sk++] = sk;
+					iter->batch[iter->end_sk++].sock = sk;
 				}
 				batch_sks++;
 			}
@@ -3478,7 +3482,7 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
 				return ERR_PTR(err);
 			}
 
-			sk = iter->batch[iter->end_sk - 1];
+			sk = iter->batch[iter->end_sk - 1].sock;
 			sk = hlist_entry_safe(sk->__sk_common.skc_portaddr_node.next,
 					      struct sock,
 					      __sk_common.skc_portaddr_node);
@@ -3504,11 +3508,11 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
 		 * socket to be iterated from the batch.
 		 */
 		iter->st_bucket_done = true;
-		return iter->batch[0];
+		return iter->batch[0].sock;
 	}
 
 	if (WARN_ON_ONCE(resizes >= MAX_REALLOC_ATTEMPTS))
-		return iter->batch[0];
+		return iter->batch[0].sock;
 
 	err = bpf_iter_udp_realloc_batch(iter, batch_sks * 3 / 2, GFP_USER);
 	if (err)
@@ -3527,15 +3531,15 @@ static void *bpf_iter_udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	 * done with seq_show(), so unref the iter->cur_sk.
 	 */
 	if (iter->cur_sk < iter->end_sk) {
-		sock_put(iter->batch[iter->cur_sk++]);
+		sock_put(iter->batch[iter->cur_sk++].sock);
 		++iter->offset;
 	}
 
 	/* After updating iter->cur_sk, check if there are more sockets
 	 * available in the current bucket batch.
 	 */
 	if (iter->cur_sk < iter->end_sk)
-		sk = iter->batch[iter->cur_sk];
+		sk = iter->batch[iter->cur_sk].sock;
 	else
 		/* Prepare a new batch. */
 		sk = bpf_iter_udp_batch(seq);
@@ -3600,7 +3604,7 @@ static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
 static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter)
 {
 	while (iter->cur_sk < iter->end_sk)
-		sock_put(iter->batch[iter->cur_sk++]);
+		sock_put(iter->batch[iter->cur_sk++].sock);
 }
 
 static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
@@ -3863,7 +3867,7 @@ DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
 static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
 				      unsigned int new_batch_sz, int flags)
 {
-	struct sock **new_batch;
+	union bpf_udp_iter_batch_item *new_batch;
 
 	new_batch = kvmalloc_array(new_batch_sz, sizeof(*new_batch),
 				   flags | __GFP_NOWARN);