net/core/skbuff.c

917 	struct sk_buff *skb = *pskb, *nskb;
937 	nskb = napi_build_skb(data, truesize);
938 	if (!nskb) {
943 	skb_reserve(nskb, headroom);
944 	skb_copy_header(nskb, skb);
945 	skb_mark_for_recycle(nskb);
947 	err = skb_copy_bits(skb, 0, nskb->data, size);
949 		consume_skb(nskb);
952 	skb_put(nskb, size);
954 	head_off = skb_headroom(nskb) - skb_headroom(skb);
955 	skb_headers_offset_update(nskb, head_off);
968 			consume_skb(nskb);
972 		skb_add_rx_frag(nskb, i, page, page_off, size, truesize);
976 			consume_skb(nskb);
985 	*pskb = nskb;
1901 static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig,
1905 		if (skb_zcopy(nskb)) {
1906 			/* !gfp_mask callers are verified to !skb_zcopy(nskb) */
1911 			if (skb_uarg(nskb) == skb_uarg(orig))
1913 			if (skb_copy_ubufs(nskb, GFP_ATOMIC))
1916 		skb_zcopy_set(nskb, skb_uarg(orig), NULL);
2402 		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2404 		if (unlikely(!nskb))
2408 			skb_set_owner_w(nskb, sk);
2410 		skb = nskb;
4497 	struct sk_buff *nskb, *tmp;
4510 		nskb = list_skb;
4514 		delta_truesize += nskb->truesize;
4515 		if (skb_shared(nskb)) {
4516 			tmp = skb_clone(nskb, GFP_ATOMIC);
4518 				consume_skb(nskb);
4519 				nskb = tmp;
4520 				err = skb_unclone(nskb, GFP_ATOMIC);
4527 			skb->next = nskb;
4529 			tail->next = nskb;
4532 			nskb->next = list_skb;
4536 		tail = nskb;
4538 		delta_len += nskb->len;
4540 		skb_push(nskb, -skb_network_offset(nskb) + offset);
4542 		skb_release_head_state(nskb);
4543 		len_diff = skb_network_header_len(nskb) - skb_network_header_len(skb);
4544 		__copy_skb_header(nskb, skb);
4546 		skb_headers_offset_update(nskb, skb_headroom(nskb) - skb_headroom(skb));
4547 		nskb->transport_header += len_diff;
4549 						 nskb->data - tnl_hlen,
4552 		if (skb_needs_linearize(nskb, features) &&
4553 		    __skb_linearize(nskb))
4694 		struct sk_buff *nskb;
4713 			nskb = skb_clone(list_skb, GFP_ATOMIC);
4714 			if (unlikely(!nskb))
4737 			if (unlikely(pskb_trim(nskb, len))) {
4738 				kfree_skb(nskb);
4742 			hsize = skb_end_offset(nskb);
4743 			if (skb_cow_head(nskb, doffset + headroom)) {
4744 				kfree_skb(nskb);
4748 			nskb->truesize += skb_end_offset(nskb) - hsize;
4749 			skb_release_head_state(nskb);
4750 			__skb_push(nskb, doffset);
4757 			nskb = __alloc_skb(hsize + doffset + headroom,
4761 			if (unlikely(!nskb))
4764 			skb_reserve(nskb, headroom);
4765 			__skb_put(nskb, doffset);
4769 			tail->next = nskb;
4771 			segs = nskb;
4772 		tail = nskb;
4774 		__copy_skb_header(nskb, head_skb);
4776 		skb_headers_offset_update(nskb, skb_headroom(nskb) - headroom);
4777 		skb_reset_mac_len(nskb);
4780 						 nskb->data - tnl_hlen,
4783 		if (nskb->len == len + doffset)
4788 				if (!nskb->remcsum_offload)
4789 					nskb->ip_summed = CHECKSUM_NONE;
4790 				SKB_GSO_CB(nskb)->csum =
4792 							       skb_put(nskb,
4795 				SKB_GSO_CB(nskb)->csum_start =
4796 					skb_headroom(nskb) + doffset;
4798 				if (skb_copy_bits(head_skb, offset, skb_put(nskb, len), len))
4804 		nskb_frag = skb_shinfo(nskb)->frags;
4807 						 skb_put(nskb, hsize), hsize);
4809 		skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags &
4812 		if (skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC))
4818 				    skb_zerocopy_clone(nskb, list_skb,
4839 			if (unlikely(skb_shinfo(nskb)->nr_frags >=
4857 			skb_shinfo(nskb)->nr_frags++;
4872 		nskb->data_len = len - hsize;
4873 		nskb->len += nskb->data_len;
4874 		nskb->truesize += nskb->data_len;
4878 			if (skb_has_shared_frag(nskb) &&
4879 			    __skb_linearize(nskb))
4882 			if (!nskb->remcsum_offload)
4883 				nskb->ip_summed = CHECKSUM_NONE;
4884 			SKB_GSO_CB(nskb)->csum =
4885 				skb_checksum(nskb, doffset,
4886 					     nskb->len - doffset, 0);
4887 			SKB_GSO_CB(nskb)->csum_start =
4888 				skb_headroom(nskb) + doffset;