From 3a1296a38d0cf62bffb9a03c585cbd5dbf15d596 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Sat, 25 Jan 2020 11:26:44 +0100 Subject: [PATCH] net: Support GRO/GSO fraglist chaining. This patch adds the core functions to chain/unchain GSO skbs at the frag_list pointer. This also adds a new GSO type SKB_GSO_FRAGLIST and a is_flist flag to napi_gro_cb which indicates that this flow will be GROed by fraglist chaining. Signed-off-by: Steffen Klassert Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 +- include/linux/skbuff.h | 2 + net/core/dev.c | 2 +- net/core/skbuff.c | 91 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 97 insertions(+), 2 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index fcc76b890f50..20445f94eb1c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2326,7 +2326,8 @@ struct napi_gro_cb { /* Number of gro_receive callbacks this packet already went through */ u8 recursion_counter:4; - /* 1 bit hole */ + /* GRO is done by frag_list pointer chaining. */ + u8 is_flist:1; /* used to support CHECKSUM_COMPLETE for tunneling protocols */ __wsum csum; @@ -2694,6 +2695,7 @@ struct net_device *dev_get_by_napi_id(unsigned int napi_id); int netdev_get_name(struct net *net, char *name, int ifindex); int dev_restart(struct net_device *dev); int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb); +int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb); static inline unsigned int skb_gro_offset(const struct sk_buff *skb) { diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 23aaaf08e1e9..3d13a4b717e9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3535,6 +3535,8 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet); bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu); bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); +struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features, + unsigned int offset); struct sk_buff *skb_vlan_untag(struct sk_buff *skb); int skb_ensure_writable(struct sk_buff *skb, int write_len); int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); diff --git a/net/core/dev.c b/net/core/dev.c index a3b154a4b4f9..ce8900dbd9ea 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3249,7 +3249,7 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, segs = skb_mac_gso_segment(skb, features); - if (unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs))) + if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs))) skb_warn_bad_offload(skb); return segs; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 48a7029529c9..864cb9e9622f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3639,6 +3639,97 @@ static inline skb_frag_t skb_head_frag_to_page_desc(struct sk_buff *frag_skb) return head_frag; } +struct sk_buff *skb_segment_list(struct sk_buff *skb, + netdev_features_t features, + unsigned int offset) +{ + struct sk_buff *list_skb = skb_shinfo(skb)->frag_list; + unsigned int tnl_hlen = skb_tnl_header_len(skb); + unsigned int delta_truesize = 0; + unsigned int delta_len = 0; + struct sk_buff *tail = NULL; + struct sk_buff *nskb; + + skb_push(skb, -skb_network_offset(skb) + offset); + + skb_shinfo(skb)->frag_list = NULL; + + do { + nskb = list_skb; + list_skb = list_skb->next; + + if (!tail) + skb->next = nskb; + else + tail->next = nskb; + + tail = nskb; + + delta_len += nskb->len; + delta_truesize += nskb->truesize; + + skb_push(nskb, -skb_network_offset(nskb) + offset); + + __copy_skb_header(nskb, skb); + + skb_headers_offset_update(nskb, skb_headroom(nskb) - skb_headroom(skb)); + skb_copy_from_linear_data_offset(skb, -tnl_hlen, + nskb->data - tnl_hlen, + offset + tnl_hlen); + + if (skb_needs_linearize(nskb, features) && + __skb_linearize(nskb)) + goto err_linearize; + + } while (list_skb); + + skb->truesize = skb->truesize - delta_truesize; + skb->data_len = skb->data_len - delta_len; + skb->len = skb->len - delta_len; + + skb_gso_reset(skb); + + skb->prev = tail; + + if (skb_needs_linearize(skb, features) && + __skb_linearize(skb)) + goto err_linearize; + + skb_get(skb); + + return skb; + +err_linearize: + kfree_skb_list(skb->next); + skb->next = NULL; + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(skb_segment_list); + +int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb) +{ + if (unlikely(p->len + skb->len >= 65536)) + return -E2BIG; + + if (NAPI_GRO_CB(p)->last == p) + skb_shinfo(p)->frag_list = skb; + else + NAPI_GRO_CB(p)->last->next = skb; + + skb_pull(skb, skb_gro_offset(skb)); + + NAPI_GRO_CB(p)->last = skb; + NAPI_GRO_CB(p)->count++; + p->data_len += skb->len; + p->truesize += skb->truesize; + p->len += skb->len; + + NAPI_GRO_CB(skb)->same_flow = 1; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_gro_receive_list); + /** * skb_segment - Perform protocol segmentation on skb. * @head_skb: buffer to segment -- 2.30.2