| // SPDX-License-Identifier: GPL-2.0-or-later |
| #include <net/gro.h> |
| #include <net/dst_metadata.h> |
| #include <net/busy_poll.h> |
| #include <trace/events/net.h> |
| |
| #define MAX_GRO_SKBS 8 |
| |
| /* This should be increased if a protocol with a bigger head is added. */ |
| #define GRO_MAX_HEAD (MAX_HEADER + 128) |
| |
| static DEFINE_SPINLOCK(offload_lock); |
| static struct list_head offload_base __read_mostly = LIST_HEAD_INIT(offload_base); |
| /* Maximum number of GRO_NORMAL skbs to batch up for list-RX */ |
| int gro_normal_batch __read_mostly = 8; |
| |
| /** |
| * dev_add_offload - register offload handlers |
| * @po: protocol offload declaration |
| * |
| * Add protocol offload handlers to the networking stack. The passed |
| * &proto_offload is linked into kernel lists and may not be freed until |
| * it has been removed from the kernel lists. |
| * |
| * This call does not sleep therefore it can not |
| * guarantee all CPU's that are in middle of receiving packets |
| * will see the new offload handlers (until the next received packet). |
| */ |
| void dev_add_offload(struct packet_offload *po) |
| { |
| struct packet_offload *elem; |
| |
| spin_lock(&offload_lock); |
| list_for_each_entry(elem, &offload_base, list) { |
| if (po->priority < elem->priority) |
| break; |
| } |
| list_add_rcu(&po->list, elem->list.prev); |
| spin_unlock(&offload_lock); |
| } |
| EXPORT_SYMBOL(dev_add_offload); |
| |
| /** |
| * __dev_remove_offload - remove offload handler |
| * @po: packet offload declaration |
| * |
| * Remove a protocol offload handler that was previously added to the |
| * kernel offload handlers by dev_add_offload(). The passed &offload_type |
| * is removed from the kernel lists and can be freed or reused once this |
| * function returns. |
| * |
| * The packet type might still be in use by receivers |
| * and must not be freed until after all the CPU's have gone |
| * through a quiescent state. |
| */ |
| static void __dev_remove_offload(struct packet_offload *po) |
| { |
| struct list_head *head = &offload_base; |
| struct packet_offload *po1; |
| |
| spin_lock(&offload_lock); |
| |
| list_for_each_entry(po1, head, list) { |
| if (po == po1) { |
| list_del_rcu(&po->list); |
| goto out; |
| } |
| } |
| |
| pr_warn("dev_remove_offload: %p not found\n", po); |
| out: |
| spin_unlock(&offload_lock); |
| } |
| |
| /** |
| * dev_remove_offload - remove packet offload handler |
| * @po: packet offload declaration |
| * |
| * Remove a packet offload handler that was previously added to the kernel |
| * offload handlers by dev_add_offload(). The passed &offload_type is |
| * removed from the kernel lists and can be freed or reused once this |
| * function returns. |
| * |
| * This call sleeps to guarantee that no CPU is looking at the packet |
| * type after return. |
| */ |
| void dev_remove_offload(struct packet_offload *po) |
| { |
| __dev_remove_offload(po); |
| |
| synchronize_net(); |
| } |
| EXPORT_SYMBOL(dev_remove_offload); |
| |
| /** |
| * skb_eth_gso_segment - segmentation handler for ethernet protocols. |
| * @skb: buffer to segment |
| * @features: features for the output path (see dev->features) |
| * @type: Ethernet Protocol ID |
| */ |
| struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, |
| netdev_features_t features, __be16 type) |
| { |
| struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT); |
| struct packet_offload *ptype; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(ptype, &offload_base, list) { |
| if (ptype->type == type && ptype->callbacks.gso_segment) { |
| segs = ptype->callbacks.gso_segment(skb, features); |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| |
| return segs; |
| } |
| EXPORT_SYMBOL(skb_eth_gso_segment); |
| |
| /** |
| * skb_mac_gso_segment - mac layer segmentation handler. |
| * @skb: buffer to segment |
| * @features: features for the output path (see dev->features) |
| */ |
| struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb, |
| netdev_features_t features) |
| { |
| struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT); |
| struct packet_offload *ptype; |
| int vlan_depth = skb->mac_len; |
| __be16 type = skb_network_protocol(skb, &vlan_depth); |
| |
| if (unlikely(!type)) |
| return ERR_PTR(-EINVAL); |
| |
| __skb_pull(skb, vlan_depth); |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(ptype, &offload_base, list) { |
| if (ptype->type == type && ptype->callbacks.gso_segment) { |
| segs = ptype->callbacks.gso_segment(skb, features); |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| |
| __skb_push(skb, skb->data - skb_mac_header(skb)); |
| |
| return segs; |
| } |
| EXPORT_SYMBOL(skb_mac_gso_segment); |
| |
| int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) |
| { |
| struct skb_shared_info *pinfo, *skbinfo = skb_shinfo(skb); |
| unsigned int offset = skb_gro_offset(skb); |
| unsigned int headlen = skb_headlen(skb); |
| unsigned int len = skb_gro_len(skb); |
| unsigned int delta_truesize; |
| unsigned int gro_max_size; |
| unsigned int new_truesize; |
| struct sk_buff *lp; |
| |
| /* pairs with WRITE_ONCE() in netif_set_gro_max_size() */ |
| gro_max_size = READ_ONCE(p->dev->gro_max_size); |
| |
| if (unlikely(p->len + len >= gro_max_size || NAPI_GRO_CB(skb)->flush)) |
| return -E2BIG; |
| |
| if (unlikely(p->len + len >= GRO_LEGACY_MAX_SIZE)) { |
| if (p->protocol != htons(ETH_P_IPV6) || |
| skb_headroom(p) < sizeof(struct hop_jumbo_hdr) || |
| ipv6_hdr(p)->nexthdr != IPPROTO_TCP || |
| p->encapsulation) |
| return -E2BIG; |
| } |
| |
| lp = NAPI_GRO_CB(p)->last; |
| pinfo = skb_shinfo(lp); |
| |
| if (headlen <= offset) { |
| skb_frag_t *frag; |
| skb_frag_t *frag2; |
| int i = skbinfo->nr_frags; |
| int nr_frags = pinfo->nr_frags + i; |
| |
| if (nr_frags > MAX_SKB_FRAGS) |
| goto merge; |
| |
| offset -= headlen; |
| pinfo->nr_frags = nr_frags; |
| skbinfo->nr_frags = 0; |
| |
| frag = pinfo->frags + nr_frags; |
| frag2 = skbinfo->frags + i; |
| do { |
| *--frag = *--frag2; |
| } while (--i); |
| |
| skb_frag_off_add(frag, offset); |
| skb_frag_size_sub(frag, offset); |
| |
| /* all fragments truesize : remove (head size + sk_buff) */ |
| new_truesize = SKB_TRUESIZE(skb_end_offset(skb)); |
| delta_truesize = skb->truesize - new_truesize; |
| |
| skb->truesize = new_truesize; |
| skb->len -= skb->data_len; |
| skb->data_len = 0; |
| |
| NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE; |
| goto done; |
| } else if (skb->head_frag) { |
| int nr_frags = pinfo->nr_frags; |
| skb_frag_t *frag = pinfo->frags + nr_frags; |
| struct page *page = virt_to_head_page(skb->head); |
| unsigned int first_size = headlen - offset; |
| unsigned int first_offset; |
| |
| if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS) |
| goto merge; |
| |
| first_offset = skb->data - |
| (unsigned char *)page_address(page) + |
| offset; |
| |
| pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags; |
| |
| __skb_frag_set_page(frag, page); |
| skb_frag_off_set(frag, first_offset); |
| skb_frag_size_set(frag, first_size); |
| |
| memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); |
| /* We dont need to clear skbinfo->nr_frags here */ |
| |
| new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff)); |
| delta_truesize = skb->truesize - new_truesize; |
| skb->truesize = new_truesize; |
| NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; |
| goto done; |
| } |
| |
| merge: |
| /* sk owenrship - if any - completely transferred to the aggregated packet */ |
| skb->destructor = NULL; |
| delta_truesize = skb->truesize; |
| if (offset > headlen) { |
| unsigned int eat = offset - headlen; |
| |
| skb_frag_off_add(&skbinfo->frags[0], eat); |
| skb_frag_size_sub(&skbinfo->frags[0], eat); |
| skb->data_len -= eat; |
| skb->len -= eat; |
| offset = headlen; |
| } |
| |
| __skb_pull(skb, offset); |
| |
| if (NAPI_GRO_CB(p)->last == p) |
| skb_shinfo(p)->frag_list = skb; |
| else |
| NAPI_GRO_CB(p)->last->next = skb; |
| NAPI_GRO_CB(p)->last = skb; |
| __skb_header_release(skb); |
| lp = p; |
| |
| done: |
| NAPI_GRO_CB(p)->count++; |
| p->data_len += len; |
| p->truesize += delta_truesize; |
| p->len += len; |
| if (lp != p) { |
| lp->data_len += len; |
| lp->truesize += delta_truesize; |
| lp->len += len; |
| } |
| NAPI_GRO_CB(skb)->same_flow = 1; |
| return 0; |
| } |
| |
| |
| static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb) |
| { |
| struct packet_offload *ptype; |
| __be16 type = skb->protocol; |
| struct list_head *head = &offload_base; |
| int err = -ENOENT; |
| |
| BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb)); |
| |
| if (NAPI_GRO_CB(skb)->count == 1) { |
| skb_shinfo(skb)->gso_size = 0; |
| goto out; |
| } |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(ptype, head, list) { |
| if (ptype->type != type || !ptype->callbacks.gro_complete) |
| continue; |
| |
| err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete, |
| ipv6_gro_complete, inet_gro_complete, |
| skb, 0); |
| break; |
| } |
| rcu_read_unlock(); |
| |
| if (err) { |
| WARN_ON(&ptype->list == head); |
| kfree_skb(skb); |
| return; |
| } |
| |
| out: |
| gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count); |
| } |
| |
| static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index, |
| bool flush_old) |
| { |
| struct list_head *head = &napi->gro_hash[index].list; |
| struct sk_buff *skb, *p; |
| |
| list_for_each_entry_safe_reverse(skb, p, head, list) { |
| if (flush_old && NAPI_GRO_CB(skb)->age == jiffies) |
| return; |
| skb_list_del_init(skb); |
| napi_gro_complete(napi, skb); |
| napi->gro_hash[index].count--; |
| } |
| |
| if (!napi->gro_hash[index].count) |
| __clear_bit(index, &napi->gro_bitmask); |
| } |
| |
| /* napi->gro_hash[].list contains packets ordered by age. |
| * youngest packets at the head of it. |
| * Complete skbs in reverse order to reduce latencies. |
| */ |
| void napi_gro_flush(struct napi_struct *napi, bool flush_old) |
| { |
| unsigned long bitmask = napi->gro_bitmask; |
| unsigned int i, base = ~0U; |
| |
| while ((i = ffs(bitmask)) != 0) { |
| bitmask >>= i; |
| base += i; |
| __napi_gro_flush_chain(napi, base, flush_old); |
| } |
| } |
| EXPORT_SYMBOL(napi_gro_flush); |
| |
| static void gro_list_prepare(const struct list_head *head, |
| const struct sk_buff *skb) |
| { |
| unsigned int maclen = skb->dev->hard_header_len; |
| u32 hash = skb_get_hash_raw(skb); |
| struct sk_buff *p; |
| |
| list_for_each_entry(p, head, list) { |
| unsigned long diffs; |
| |
| NAPI_GRO_CB(p)->flush = 0; |
| |
| if (hash != skb_get_hash_raw(p)) { |
| NAPI_GRO_CB(p)->same_flow = 0; |
| continue; |
| } |
| |
| diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; |
| diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb); |
| if (skb_vlan_tag_present(p)) |
| diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb); |
| diffs |= skb_metadata_differs(p, skb); |
| if (maclen == ETH_HLEN) |
| diffs |= compare_ether_header(skb_mac_header(p), |
| skb_mac_header(skb)); |
| else if (!diffs) |
| diffs = memcmp(skb_mac_header(p), |
| skb_mac_header(skb), |
| maclen); |
| |
| /* in most common scenarions 'slow_gro' is 0 |
| * otherwise we are already on some slower paths |
| * either skip all the infrequent tests altogether or |
| * avoid trying too hard to skip each of them individually |
| */ |
| if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) { |
| #if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT) |
| struct tc_skb_ext *skb_ext; |
| struct tc_skb_ext *p_ext; |
| #endif |
| |
| diffs |= p->sk != skb->sk; |
| diffs |= skb_metadata_dst_cmp(p, skb); |
| diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); |
| |
| #if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT) |
| skb_ext = skb_ext_find(skb, TC_SKB_EXT); |
| p_ext = skb_ext_find(p, TC_SKB_EXT); |
| |
| diffs |= (!!p_ext) ^ (!!skb_ext); |
| if (!diffs && unlikely(skb_ext)) |
| diffs |= p_ext->chain ^ skb_ext->chain; |
| #endif |
| } |
| |
| NAPI_GRO_CB(p)->same_flow = !diffs; |
| } |
| } |
| |
| static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff) |
| { |
| const struct skb_shared_info *pinfo = skb_shinfo(skb); |
| const skb_frag_t *frag0 = &pinfo->frags[0]; |
| |
| NAPI_GRO_CB(skb)->data_offset = 0; |
| NAPI_GRO_CB(skb)->frag0 = NULL; |
| NAPI_GRO_CB(skb)->frag0_len = 0; |
| |
| if (!skb_headlen(skb) && pinfo->nr_frags && |
| !PageHighMem(skb_frag_page(frag0)) && |
| (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) { |
| NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0); |
| NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int, |
| skb_frag_size(frag0), |
| skb->end - skb->tail); |
| } |
| } |
| |
| static void gro_pull_from_frag0(struct sk_buff *skb, int grow) |
| { |
| struct skb_shared_info *pinfo = skb_shinfo(skb); |
| |
| BUG_ON(skb->end - skb->tail < grow); |
| |
| memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow); |
| |
| skb->data_len -= grow; |
| skb->tail += grow; |
| |
| skb_frag_off_add(&pinfo->frags[0], grow); |
| skb_frag_size_sub(&pinfo->frags[0], grow); |
| |
| if (unlikely(!skb_frag_size(&pinfo->frags[0]))) { |
| skb_frag_unref(skb, 0); |
| memmove(pinfo->frags, pinfo->frags + 1, |
| --pinfo->nr_frags * sizeof(pinfo->frags[0])); |
| } |
| } |
| |
| static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head) |
| { |
| struct sk_buff *oldest; |
| |
| oldest = list_last_entry(head, struct sk_buff, list); |
| |
| /* We are called with head length >= MAX_GRO_SKBS, so this is |
| * impossible. |
| */ |
| if (WARN_ON_ONCE(!oldest)) |
| return; |
| |
| /* Do not adjust napi->gro_hash[].count, caller is adding a new |
| * SKB to the chain. |
| */ |
| skb_list_del_init(oldest); |
| napi_gro_complete(napi, oldest); |
| } |
| |
| static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb) |
| { |
| u32 bucket = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1); |
| struct gro_list *gro_list = &napi->gro_hash[bucket]; |
| struct list_head *head = &offload_base; |
| struct packet_offload *ptype; |
| __be16 type = skb->protocol; |
| struct sk_buff *pp = NULL; |
| enum gro_result ret; |
| int same_flow; |
| int grow; |
| |
| if (netif_elide_gro(skb->dev)) |
| goto normal; |
| |
| gro_list_prepare(&gro_list->list, skb); |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(ptype, head, list) { |
| if (ptype->type != type || !ptype->callbacks.gro_receive) |
| continue; |
| |
| skb_set_network_header(skb, skb_gro_offset(skb)); |
| skb_reset_mac_len(skb); |
| BUILD_BUG_ON(sizeof_field(struct napi_gro_cb, zeroed) != sizeof(u32)); |
| BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct napi_gro_cb, zeroed), |
| sizeof(u32))); /* Avoid slow unaligned acc */ |
| *(u32 *)&NAPI_GRO_CB(skb)->zeroed = 0; |
| NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb); |
| NAPI_GRO_CB(skb)->is_atomic = 1; |
| |
| /* Setup for GRO checksum validation */ |
| switch (skb->ip_summed) { |
| case CHECKSUM_COMPLETE: |
| NAPI_GRO_CB(skb)->csum = skb->csum; |
| NAPI_GRO_CB(skb)->csum_valid = 1; |
| break; |
| case CHECKSUM_UNNECESSARY: |
| NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1; |
| break; |
| } |
| |
| pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive, |
| ipv6_gro_receive, inet_gro_receive, |
| &gro_list->list, skb); |
| break; |
| } |
| rcu_read_unlock(); |
| |
| if (&ptype->list == head) |
| goto normal; |
| |
| if (PTR_ERR(pp) == -EINPROGRESS) { |
| ret = GRO_CONSUMED; |
| goto ok; |
| } |
| |
| same_flow = NAPI_GRO_CB(skb)->same_flow; |
| ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED; |
| |
| if (pp) { |
| skb_list_del_init(pp); |
| napi_gro_complete(napi, pp); |
| gro_list->count--; |
| } |
| |
| if (same_flow) |
| goto ok; |
| |
| if (NAPI_GRO_CB(skb)->flush) |
| goto normal; |
| |
| if (unlikely(gro_list->count >= MAX_GRO_SKBS)) |
| gro_flush_oldest(napi, &gro_list->list); |
| else |
| gro_list->count++; |
| |
| NAPI_GRO_CB(skb)->count = 1; |
| NAPI_GRO_CB(skb)->age = jiffies; |
| NAPI_GRO_CB(skb)->last = skb; |
| skb_shinfo(skb)->gso_size = skb_gro_len(skb); |
| list_add(&skb->list, &gro_list->list); |
| ret = GRO_HELD; |
| |
| pull: |
| grow = skb_gro_offset(skb) - skb_headlen(skb); |
| if (grow > 0) |
| gro_pull_from_frag0(skb, grow); |
| ok: |
| if (gro_list->count) { |
| if (!test_bit(bucket, &napi->gro_bitmask)) |
| __set_bit(bucket, &napi->gro_bitmask); |
| } else if (test_bit(bucket, &napi->gro_bitmask)) { |
| __clear_bit(bucket, &napi->gro_bitmask); |
| } |
| |
| return ret; |
| |
| normal: |
| ret = GRO_NORMAL; |
| goto pull; |
| } |
| |
| struct packet_offload *gro_find_receive_by_type(__be16 type) |
| { |
| struct list_head *offload_head = &offload_base; |
| struct packet_offload *ptype; |
| |
| list_for_each_entry_rcu(ptype, offload_head, list) { |
| if (ptype->type != type || !ptype->callbacks.gro_receive) |
| continue; |
| return ptype; |
| } |
| return NULL; |
| } |
| EXPORT_SYMBOL(gro_find_receive_by_type); |
| |
| struct packet_offload *gro_find_complete_by_type(__be16 type) |
| { |
| struct list_head *offload_head = &offload_base; |
| struct packet_offload *ptype; |
| |
| list_for_each_entry_rcu(ptype, offload_head, list) { |
| if (ptype->type != type || !ptype->callbacks.gro_complete) |
| continue; |
| return ptype; |
| } |
| return NULL; |
| } |
| EXPORT_SYMBOL(gro_find_complete_by_type); |
| |
| static gro_result_t napi_skb_finish(struct napi_struct *napi, |
| struct sk_buff *skb, |
| gro_result_t ret) |
| { |
| switch (ret) { |
| case GRO_NORMAL: |
| gro_normal_one(napi, skb, 1); |
| break; |
| |
| case GRO_MERGED_FREE: |
| if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) |
| napi_skb_free_stolen_head(skb); |
| else if (skb->fclone != SKB_FCLONE_UNAVAILABLE) |
| __kfree_skb(skb); |
| else |
| __kfree_skb_defer(skb); |
| break; |
| |
| case GRO_HELD: |
| case GRO_MERGED: |
| case GRO_CONSUMED: |
| break; |
| } |
| |
| return ret; |
| } |
| |
| gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb) |
| { |
| gro_result_t ret; |
| |
| skb_mark_napi_id(skb, napi); |
| trace_napi_gro_receive_entry(skb); |
| |
| skb_gro_reset_offset(skb, 0); |
| |
| ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb)); |
| trace_napi_gro_receive_exit(ret); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(napi_gro_receive); |
| |
| static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) |
| { |
| if (unlikely(skb->pfmemalloc)) { |
| consume_skb(skb); |
| return; |
| } |
| __skb_pull(skb, skb_headlen(skb)); |
| /* restore the reserve we had after netdev_alloc_skb_ip_align() */ |
| skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb)); |
| __vlan_hwaccel_clear_tag(skb); |
| skb->dev = napi->dev; |
| skb->skb_iif = 0; |
| |
| /* eth_type_trans() assumes pkt_type is PACKET_HOST */ |
| skb->pkt_type = PACKET_HOST; |
| |
| skb->encapsulation = 0; |
| skb_shinfo(skb)->gso_type = 0; |
| if (unlikely(skb->slow_gro)) { |
| skb_orphan(skb); |
| skb_ext_reset(skb); |
| nf_reset_ct(skb); |
| skb->slow_gro = 0; |
| } |
| |
| napi->skb = skb; |
| } |
| |
| struct sk_buff *napi_get_frags(struct napi_struct *napi) |
| { |
| struct sk_buff *skb = napi->skb; |
| |
| if (!skb) { |
| skb = napi_alloc_skb(napi, GRO_MAX_HEAD); |
| if (skb) { |
| napi->skb = skb; |
| skb_mark_napi_id(skb, napi); |
| } |
| } |
| return skb; |
| } |
| EXPORT_SYMBOL(napi_get_frags); |
| |
| static gro_result_t napi_frags_finish(struct napi_struct *napi, |
| struct sk_buff *skb, |
| gro_result_t ret) |
| { |
| switch (ret) { |
| case GRO_NORMAL: |
| case GRO_HELD: |
| __skb_push(skb, ETH_HLEN); |
| skb->protocol = eth_type_trans(skb, skb->dev); |
| if (ret == GRO_NORMAL) |
| gro_normal_one(napi, skb, 1); |
| break; |
| |
| case GRO_MERGED_FREE: |
| if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) |
| napi_skb_free_stolen_head(skb); |
| else |
| napi_reuse_skb(napi, skb); |
| break; |
| |
| case GRO_MERGED: |
| case GRO_CONSUMED: |
| break; |
| } |
| |
| return ret; |
| } |
| |
| /* Upper GRO stack assumes network header starts at gro_offset=0 |
| * Drivers could call both napi_gro_frags() and napi_gro_receive() |
| * We copy ethernet header into skb->data to have a common layout. |
| */ |
| static struct sk_buff *napi_frags_skb(struct napi_struct *napi) |
| { |
| struct sk_buff *skb = napi->skb; |
| const struct ethhdr *eth; |
| unsigned int hlen = sizeof(*eth); |
| |
| napi->skb = NULL; |
| |
| skb_reset_mac_header(skb); |
| skb_gro_reset_offset(skb, hlen); |
| |
| if (unlikely(skb_gro_header_hard(skb, hlen))) { |
| eth = skb_gro_header_slow(skb, hlen, 0); |
| if (unlikely(!eth)) { |
| net_warn_ratelimited("%s: dropping impossible skb from %s\n", |
| __func__, napi->dev->name); |
| napi_reuse_skb(napi, skb); |
| return NULL; |
| } |
| } else { |
| eth = (const struct ethhdr *)skb->data; |
| gro_pull_from_frag0(skb, hlen); |
| NAPI_GRO_CB(skb)->frag0 += hlen; |
| NAPI_GRO_CB(skb)->frag0_len -= hlen; |
| } |
| __skb_pull(skb, hlen); |
| |
| /* |
| * This works because the only protocols we care about don't require |
| * special handling. |
| * We'll fix it up properly in napi_frags_finish() |
| */ |
| skb->protocol = eth->h_proto; |
| |
| return skb; |
| } |
| |
| gro_result_t napi_gro_frags(struct napi_struct *napi) |
| { |
| gro_result_t ret; |
| struct sk_buff *skb = napi_frags_skb(napi); |
| |
| trace_napi_gro_frags_entry(skb); |
| |
| ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb)); |
| trace_napi_gro_frags_exit(ret); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(napi_gro_frags); |
| |
| /* Compute the checksum from gro_offset and return the folded value |
| * after adding in any pseudo checksum. |
| */ |
| __sum16 __skb_gro_checksum_complete(struct sk_buff *skb) |
| { |
| __wsum wsum; |
| __sum16 sum; |
| |
| wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0); |
| |
| /* NAPI_GRO_CB(skb)->csum holds pseudo checksum */ |
| sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum)); |
| /* See comments in __skb_checksum_complete(). */ |
| if (likely(!sum)) { |
| if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && |
| !skb->csum_complete_sw) |
| netdev_rx_csum_fault(skb->dev, skb); |
| } |
| |
| NAPI_GRO_CB(skb)->csum = wsum; |
| NAPI_GRO_CB(skb)->csum_valid = 1; |
| |
| return sum; |
| } |
| EXPORT_SYMBOL(__skb_gro_checksum_complete); |