From 8cb19905e9287a93ce7c2cbbdf742a060b00e219 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 18:29:04 +0200 Subject: skbuff: skb_segment: s/frag/nskb_frag/ frag points at nskb, so name it appropriately Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 5d6236d..60e8cd7 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2876,7 +2876,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) do { struct sk_buff *nskb; - skb_frag_t *frag; + skb_frag_t *nskb_frag; int hsize; int size; @@ -2969,7 +2969,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) continue; } - frag = skb_shinfo(nskb)->frags; + nskb_frag = skb_shinfo(nskb)->frags; skb_copy_from_linear_data_offset(skb, offset, skb_put(nskb, hsize), hsize); @@ -2997,13 +2997,13 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) goto err; } - *frag = *skb_frag; - __skb_frag_ref(frag); - size = skb_frag_size(frag); + *nskb_frag = *skb_frag; + __skb_frag_ref(nskb_frag); + size = skb_frag_size(nskb_frag); if (pos < offset) { - frag->page_offset += offset - pos; - skb_frag_size_sub(frag, offset - pos); + nskb_frag->page_offset += offset - pos; + skb_frag_size_sub(nskb_frag, offset - pos); } skb_shinfo(nskb)->nr_frags++; @@ -3013,11 +3013,11 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) skb_frag++; pos += size; } else { - skb_frag_size_sub(frag, pos + size - (offset + len)); + skb_frag_size_sub(nskb_frag, pos + size - (offset + len)); goto skip_fraglist; } - frag++; + nskb_frag++; } skip_fraglist: -- cgit v0.10.2 From 4e1beba12d094c6c761ba5c49032b9b9e46380e8 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 18:29:14 +0200 Subject: skbuff: skb_segment: s/skb_frag/frag/ skb_frag can in fact point at either skb or fskb so rename it generally "frag". Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 60e8cd7..d788a98 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2850,7 +2850,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) struct sk_buff *segs = NULL; struct sk_buff *tail = NULL; struct sk_buff *fskb = skb_shinfo(skb)->frag_list; - skb_frag_t *skb_frag = skb_shinfo(skb)->frags; + skb_frag_t *frag = skb_shinfo(skb)->frags; unsigned int mss = skb_shinfo(skb)->gso_size; unsigned int doffset = skb->data - skb_mac_header(skb); unsigned int offset = doffset; @@ -2896,19 +2896,19 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) i = 0; nfrags = skb_shinfo(fskb)->nr_frags; - skb_frag = skb_shinfo(fskb)->frags; + frag = skb_shinfo(fskb)->frags; pos += skb_headlen(fskb); while (pos < offset + len) { BUG_ON(i >= nfrags); - size = skb_frag_size(skb_frag); + size = skb_frag_size(frag); if (pos + size > offset + len) break; i++; pos += size; - skb_frag++; + frag++; } nskb = skb_clone(fskb, GFP_ATOMIC); @@ -2982,7 +2982,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) i = 0; nfrags = skb_shinfo(fskb)->nr_frags; - skb_frag = skb_shinfo(fskb)->frags; + frag = skb_shinfo(fskb)->frags; BUG_ON(!nfrags); @@ -2997,7 +2997,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) goto err; } - *nskb_frag = *skb_frag; + *nskb_frag = *frag; __skb_frag_ref(nskb_frag); size = skb_frag_size(nskb_frag); @@ -3010,7 +3010,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) if (pos + size <= offset + len) { i++; - skb_frag++; + frag++; pos += size; } else { skb_frag_size_sub(nskb_frag, pos + size - (offset + len)); -- cgit v0.10.2 From df5771ffefb13f8af5392bd54fd7e2b596a3a357 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 18:29:19 +0200 Subject: skbuff: skb_segment: s/skb/head_skb/ rename local variable to make it easier to tell at a glance that we are dealing with a head skb. Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d788a98..fdc065d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2838,41 +2838,42 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum); /** * skb_segment - Perform protocol segmentation on skb. - * @skb: buffer to segment + * @head_skb: buffer to segment * @features: features for the output path (see dev->features) * * This function performs segmentation on the given skb. It returns * a pointer to the first in a list of new skbs for the segments. * In case of error it returns ERR_PTR(err). */ -struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) +struct sk_buff *skb_segment(struct sk_buff *head_skb, + netdev_features_t features) { struct sk_buff *segs = NULL; struct sk_buff *tail = NULL; - struct sk_buff *fskb = skb_shinfo(skb)->frag_list; - skb_frag_t *frag = skb_shinfo(skb)->frags; - unsigned int mss = skb_shinfo(skb)->gso_size; - unsigned int doffset = skb->data - skb_mac_header(skb); + struct sk_buff *fskb = skb_shinfo(head_skb)->frag_list; + skb_frag_t *frag = skb_shinfo(head_skb)->frags; + unsigned int mss = skb_shinfo(head_skb)->gso_size; + unsigned int doffset = head_skb->data - skb_mac_header(head_skb); unsigned int offset = doffset; - unsigned int tnl_hlen = skb_tnl_header_len(skb); + unsigned int tnl_hlen = skb_tnl_header_len(head_skb); unsigned int headroom; unsigned int len; __be16 proto; bool csum; int sg = !!(features & NETIF_F_SG); - int nfrags = skb_shinfo(skb)->nr_frags; + int nfrags = skb_shinfo(head_skb)->nr_frags; int err = -ENOMEM; int i = 0; int pos; - proto = skb_network_protocol(skb); + proto = skb_network_protocol(head_skb); if (unlikely(!proto)) return ERR_PTR(-EINVAL); csum = !!can_checksum_protocol(features, proto); - __skb_push(skb, doffset); - headroom = skb_headroom(skb); - pos = skb_headlen(skb); + __skb_push(head_skb, doffset); + headroom = skb_headroom(head_skb); + pos = skb_headlen(head_skb); do { struct sk_buff *nskb; @@ -2880,11 +2881,11 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) int hsize; int size; - len = skb->len - offset; + len = head_skb->len - offset; if (len > mss) len = mss; - hsize = skb_headlen(skb) - offset; + hsize = skb_headlen(head_skb) - offset; if (hsize < 0) hsize = 0; if (hsize > len || !sg) @@ -2933,7 +2934,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) __skb_push(nskb, doffset); } else { nskb = __alloc_skb(hsize + doffset + headroom, - GFP_ATOMIC, skb_alloc_rx_flag(skb), + GFP_ATOMIC, skb_alloc_rx_flag(head_skb), NUMA_NO_NODE); if (unlikely(!nskb)) @@ -2949,12 +2950,12 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) segs = nskb; tail = nskb; - __copy_skb_header(nskb, skb); - nskb->mac_len = skb->mac_len; + __copy_skb_header(nskb, head_skb); + nskb->mac_len = head_skb->mac_len; skb_headers_offset_update(nskb, skb_headroom(nskb) - headroom); - skb_copy_from_linear_data_offset(skb, -tnl_hlen, + skb_copy_from_linear_data_offset(head_skb, -tnl_hlen, nskb->data - tnl_hlen, doffset + tnl_hlen); @@ -2963,7 +2964,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) if (!sg) { nskb->ip_summed = CHECKSUM_NONE; - nskb->csum = skb_copy_and_csum_bits(skb, offset, + nskb->csum = skb_copy_and_csum_bits(head_skb, offset, skb_put(nskb, len), len, 0); continue; @@ -2971,10 +2972,11 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) nskb_frag = skb_shinfo(nskb)->frags; - skb_copy_from_linear_data_offset(skb, offset, + skb_copy_from_linear_data_offset(head_skb, offset, skb_put(nskb, hsize), hsize); - skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; + skb_shinfo(nskb)->tx_flags = skb_shinfo(head_skb)->tx_flags & + SKBTX_SHARED_FRAG; while (pos < offset + len) { if (i >= nfrags) { @@ -3031,7 +3033,7 @@ perform_csum_check: nskb->len - doffset, 0); nskb->ip_summed = CHECKSUM_NONE; } - } while ((offset += len) < skb->len); + } while ((offset += len) < head_skb->len); return segs; -- cgit v0.10.2 From 1a4cedaf65491e66e1e55b8428c89209da729209 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 19:27:59 +0200 Subject: skbuff: skb_segment: s/fskb/list_skb/ fskb is unrelated to frag: it's coming from frag_list. Rename it list_skb to avoid confusion. Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller diff --git a/net/core/skbuff.c b/net/core/skbuff.c index fdc065d..dc4f768 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2850,7 +2850,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, { struct sk_buff *segs = NULL; struct sk_buff *tail = NULL; - struct sk_buff *fskb = skb_shinfo(head_skb)->frag_list; + struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list; skb_frag_t *frag = skb_shinfo(head_skb)->frags; unsigned int mss = skb_shinfo(head_skb)->gso_size; unsigned int doffset = head_skb->data - skb_mac_header(head_skb); @@ -2891,14 +2891,14 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, if (hsize > len || !sg) hsize = len; - if (!hsize && i >= nfrags && skb_headlen(fskb) && - (skb_headlen(fskb) == len || sg)) { - BUG_ON(skb_headlen(fskb) > len); + if (!hsize && i >= nfrags && skb_headlen(list_skb) && + (skb_headlen(list_skb) == len || sg)) { + BUG_ON(skb_headlen(list_skb) > len); i = 0; - nfrags = skb_shinfo(fskb)->nr_frags; - frag = skb_shinfo(fskb)->frags; - pos += skb_headlen(fskb); + nfrags = skb_shinfo(list_skb)->nr_frags; + frag = skb_shinfo(list_skb)->frags; + pos += skb_headlen(list_skb); while (pos < offset + len) { BUG_ON(i >= nfrags); @@ -2912,8 +2912,8 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, frag++; } - nskb = skb_clone(fskb, GFP_ATOMIC); - fskb = fskb->next; + nskb = skb_clone(list_skb, GFP_ATOMIC); + list_skb = list_skb->next; if (unlikely(!nskb)) goto err; @@ -2980,15 +2980,15 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, while (pos < offset + len) { if (i >= nfrags) { - BUG_ON(skb_headlen(fskb)); + BUG_ON(skb_headlen(list_skb)); i = 0; - nfrags = skb_shinfo(fskb)->nr_frags; - frag = skb_shinfo(fskb)->frags; + nfrags = skb_shinfo(list_skb)->nr_frags; + frag = skb_shinfo(list_skb)->frags; BUG_ON(!nfrags); - fskb = fskb->next; + list_skb = list_skb->next; } if (unlikely(skb_shinfo(nskb)->nr_frags >= -- cgit v0.10.2 From 1fd819ecb90cc9b822cd84d3056ddba315d3340f Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 19:28:08 +0200 Subject: skbuff: skb_segment: orphan frags before copying skb_segment copies frags around, so we need to copy them carefully to avoid accessing user memory after reporting completion to userspace through a callback. skb_segment doesn't normally happen on datapath: TSO needs to be disabled - so disabling zero copy in this case does not look like a big deal. Signed-off-by: Michael S. Tsirkin Acked-by: Herbert Xu Signed-off-by: David S. Miller diff --git a/net/core/skbuff.c b/net/core/skbuff.c index dc4f768..869c7af 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2854,6 +2854,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, skb_frag_t *frag = skb_shinfo(head_skb)->frags; unsigned int mss = skb_shinfo(head_skb)->gso_size; unsigned int doffset = head_skb->data - skb_mac_header(head_skb); + struct sk_buff *frag_skb = head_skb; unsigned int offset = doffset; unsigned int tnl_hlen = skb_tnl_header_len(head_skb); unsigned int headroom; @@ -2898,6 +2899,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, i = 0; nfrags = skb_shinfo(list_skb)->nr_frags; frag = skb_shinfo(list_skb)->frags; + frag_skb = list_skb; pos += skb_headlen(list_skb); while (pos < offset + len) { @@ -2985,6 +2987,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, i = 0; nfrags = skb_shinfo(list_skb)->nr_frags; frag = skb_shinfo(list_skb)->frags; + frag_skb = list_skb; BUG_ON(!nfrags); @@ -2999,6 +3002,9 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, goto err; } + if (unlikely(skb_orphan_frags(frag_skb, GFP_ATOMIC))) + goto err; + *nskb_frag = *frag; __skb_frag_ref(nskb_frag); size = skb_frag_size(nskb_frag); -- cgit v0.10.2