Now sctp GSO uses skb_gro_receive() to append the data into head
skb frag_list. However it actually only needs very few code from
skb_gro_receive(). Besides, NAPI_GRO_CB has to be set while most
of its members are not needed here.
This patch is to add sctp_packet_gso_append() to build GSO frames
instead of skb_gro_receive(), and it would avoid many unnecessary
checks and make the code clearer.
Note that sctp will use page frags instead of frag_list to build
GSO frames in another patch. But it may take time, as sctp's GSO
frames may have different size. skb_segment() can only split it
into the frags with the same size, which would break the border
of sctp chunks.
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
---
include/net/sctp/structs.h | 5 +++++
net/sctp/output.c | 28 ++++++++++++++++++----------
2 files changed, 23 insertions(+), 10 deletions(-)
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ebf809e..dbe1b91 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1133,6 +1133,11 @@ struct sctp_input_cb {
};
#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0]))
+struct sctp_output_cb {
+ struct sk_buff *last;
+};
+#define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0]))
+
static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
{
const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
diff --git a/net/sctp/output.c b/net/sctp/output.c
index e672dee..7f849b0 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -409,6 +409,21 @@ static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk)
refcount_inc(&sk->sk_wmem_alloc);
}
+static void sctp_packet_gso_append(struct sk_buff *head, struct sk_buff *skb)
+{
+ if (SCTP_OUTPUT_CB(head)->last == head)
+ skb_shinfo(head)->frag_list = skb;
+ else
+ SCTP_OUTPUT_CB(head)->last->next = skb;
+ SCTP_OUTPUT_CB(head)->last = skb;
+
+ head->truesize += skb->truesize;
+ head->data_len += skb->len;
+ head->len += skb->len;
+
+ __skb_header_release(skb);
+}
+
static int sctp_packet_pack(struct sctp_packet *packet,
struct sk_buff *head, int gso, gfp_t gfp)
{
@@ -422,7 +437,7 @@ static int sctp_packet_pack(struct sctp_packet *packet,
if (gso) {
skb_shinfo(head)->gso_type = sk->sk_gso_type;
- NAPI_GRO_CB(head)->last = head;
+ SCTP_OUTPUT_CB(head)->last = head;
} else {
nskb = head;
pkt_size = packet->size;
@@ -503,15 +518,8 @@ static int sctp_packet_pack(struct sctp_packet *packet,
&packet->chunk_list);
}
- if (gso) {
- if (skb_gro_receive(&head, nskb)) {
- kfree_skb(nskb);
- return 0;
- }
- if (WARN_ON_ONCE(skb_shinfo(head)->gso_segs >=
- sk->sk_gso_max_segs))
- return 0;
- }
+ if (gso)
+ sctp_packet_gso_append(head, nskb);
pkt_count++;
} while (!list_empty(&packet->chunk_list));
--
2.1.0
--
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