1 files changed, 246 insertions, 56 deletions

diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index cbcdd5d..a428ac6 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -44,6 +44,8 @@
 #include <net/protocol.h>
 #include <linux/icmpv6.h>
 
+#include <linux/highmem.h>
+
 struct esp_skb_cb {
 	struct xfrm_skb_cb xfrm;
 	void *tmp;
@@ -114,11 +116,40 @@ static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
 			     __alignof__(struct scatterlist));
 }
 
+static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
+{
+	__be32 *seqhi;
+	struct crypto_aead *aead = x->data;
+	int seqhilen = 0;
+	u8 *iv;
+	struct aead_request *req;
+	struct scatterlist *sg;
+
+	if (x->props.flags & XFRM_STATE_ESN)
+		seqhilen += sizeof(__be32);
+
+	seqhi = esp_tmp_seqhi(tmp);
+	iv = esp_tmp_iv(aead, tmp, seqhilen);
+	req = esp_tmp_req(aead, iv);
+
+	/* Unref skb_frag_pages in the src scatterlist if necessary.
+	 * Skip the first sg which comes from skb->data.
+	 */
+	if (req->src != req->dst)
+		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
+			put_page(sg_page(sg));
+}
+
 static void esp_output_done(struct crypto_async_request *base, int err)
 {
 	struct sk_buff *skb = base->data;
+	void *tmp;
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x = dst->xfrm;
 
-	kfree(ESP_SKB_CB(skb)->tmp);
+	tmp = ESP_SKB_CB(skb)->tmp;
+	esp_ssg_unref(x, tmp);
+	kfree(tmp);
 	xfrm_output_resume(skb, err);
 }
 
@@ -138,6 +169,27 @@ static void esp_output_restore_header(struct sk_buff *skb)
 	esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
 }
 
+static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
+					     struct ip_esp_hdr *esph,
+					     __be32 *seqhi)
+{
+	struct xfrm_state *x = skb_dst(skb)->xfrm;
+
+	/* For ESN we move the header forward by 4 bytes to
+	 * accomodate the high bits.  We will move it back after
+	 * encryption.
+	 */
+	if ((x->props.flags & XFRM_STATE_ESN)) {
+		esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
+		*seqhi = esph->spi;
+		esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
+	}
+
+	esph->spi = x->id.spi;
+
+	return esph;
+}
+
 static void esp_output_done_esn(struct crypto_async_request *base, int err)
 {
 	struct sk_buff *skb = base->data;
@@ -152,8 +204,9 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	struct ip_esp_hdr *esph;
 	struct crypto_aead *aead;
 	struct aead_request *req;
-	struct scatterlist *sg;
+	struct scatterlist *sg, *dsg;
 	struct sk_buff *trailer;
+	struct page *page;
 	void *tmp;
 	int blksize;
 	int clen;
@@ -164,10 +217,13 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	int nfrags;
 	int assoclen;
 	int seqhilen;
+	int tailen;
 	u8 *iv;
 	u8 *tail;
+	u8 *vaddr;
 	__be32 *seqhi;
 	__be64 seqno;
+	__u8 proto = *skb_mac_header(skb);
 
 	/* skb is pure payload to encrypt */
 	aead = x->data;
@@ -186,11 +242,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
 	clen = ALIGN(skb->len + 2 + tfclen, blksize);
 	plen = clen - skb->len - tfclen;
-
-	err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
-	if (err < 0)
-		goto error;
-	nfrags = err;
+	tailen = tfclen + plen + alen;
 
 	assoclen = sizeof(*esph);
 	seqhilen = 0;
@@ -200,19 +252,130 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 		assoclen += seqhilen;
 	}
 
-	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
-	if (!tmp) {
-		err = -ENOMEM;
-		goto error;
+	*skb_mac_header(skb) = IPPROTO_ESP;
+	esph = ip_esp_hdr(skb);
+
+	if (!skb_cloned(skb)) {
+		if (tailen <= skb_availroom(skb)) {
+			nfrags = 1;
+			trailer = skb;
+			tail = skb_tail_pointer(trailer);
+
+			goto skip_cow;
+		} else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
+			   && !skb_has_frag_list(skb)) {
+			int allocsize;
+			struct sock *sk = skb->sk;
+			struct page_frag *pfrag = &x->xfrag;
+
+			allocsize = ALIGN(tailen, L1_CACHE_BYTES);
+
+			spin_lock_bh(&x->lock);
+
+			if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
+				spin_unlock_bh(&x->lock);
+				goto cow;
+			}
+
+			page = pfrag->page;
+			get_page(page);
+
+			vaddr = kmap_atomic(page);
+
+			tail = vaddr + pfrag->offset;
+
+			/* Fill padding... */
+			if (tfclen) {
+				memset(tail, 0, tfclen);
+				tail += tfclen;
+			}
+			do {
+				int i;
+				for (i = 0; i < plen - 2; i++)
+					tail[i] = i + 1;
+			} while (0);
+			tail[plen - 2] = plen - 2;
+			tail[plen - 1] = proto;
+
+			kunmap_atomic(vaddr);
+
+			nfrags = skb_shinfo(skb)->nr_frags;
+
+			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
+					     tailen);
+			skb_shinfo(skb)->nr_frags = ++nfrags;
+
+			pfrag->offset = pfrag->offset + allocsize;
+			nfrags++;
+
+			skb->len += tailen;
+			skb->data_len += tailen;
+			skb->truesize += tailen;
+			if (sk)
+				atomic_add(tailen, &sk->sk_wmem_alloc);
+
+			skb_push(skb, -skb_network_offset(skb));
+
+			esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+			esph->spi = x->id.spi;
+
+			tmp = esp_alloc_tmp(aead, nfrags + 2, seqhilen);
+			if (!tmp) {
+				spin_unlock_bh(&x->lock);
+				err = -ENOMEM;
+				goto error;
+			}
+			seqhi = esp_tmp_seqhi(tmp);
+			iv = esp_tmp_iv(aead, tmp, seqhilen);
+			req = esp_tmp_req(aead, iv);
+			sg = esp_req_sg(aead, req);
+			dsg = &sg[nfrags];
+
+			esph = esp_output_set_esn(skb, esph, seqhi);
+
+			sg_init_table(sg, nfrags);
+			skb_to_sgvec(skb, sg,
+				     (unsigned char *)esph - skb->data,
+				     assoclen + ivlen + clen + alen);
+
+			allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
+
+			if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
+				spin_unlock_bh(&x->lock);
+				err = -ENOMEM;
+				goto error;
+			}
+
+			skb_shinfo(skb)->nr_frags = 1;
+
+			page = pfrag->page;
+			get_page(page);
+			/* replace page frags in skb with new page */
+			__skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
+			pfrag->offset = pfrag->offset + allocsize;
+
+			sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
+			skb_to_sgvec(skb, dsg,
+				     (unsigned char *)esph - skb->data,
+				     assoclen + ivlen + clen + alen);
+
+			spin_unlock_bh(&x->lock);
+
+			goto skip_cow2;
+		}
 	}
 
-	seqhi = esp_tmp_seqhi(tmp);
-	iv = esp_tmp_iv(aead, tmp, seqhilen);
-	req = esp_tmp_req(aead, iv);
-	sg = esp_req_sg(aead, req);
+cow:
+	err = skb_cow_data(skb, tailen, &trailer);
+	if (err < 0)
+		goto error;
+	nfrags = err;
 
-	/* Fill padding... */
 	tail = skb_tail_pointer(trailer);
+	esph = ip_esp_hdr(skb);
+
+skip_cow:
+	/* Fill padding... */
 	if (tfclen) {
 		memset(tail, 0, tfclen);
 		tail += tfclen;
@@ -223,36 +386,40 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 			tail[i] = i + 1;
 	} while (0);
 	tail[plen - 2] = plen - 2;
-	tail[plen - 1] = *skb_mac_header(skb);
+	tail[plen - 1] = proto;
 	pskb_put(skb, trailer, clen - skb->len + alen);
 
 	skb_push(skb, -skb_network_offset(skb));
-	esph = ip_esp_hdr(skb);
-	*skb_mac_header(skb) = IPPROTO_ESP;
 
 	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+	esph->spi = x->id.spi;
 
-	aead_request_set_callback(req, 0, esp_output_done, skb);
-
-	/* For ESN we move the header forward by 4 bytes to
-	 * accomodate the high bits.  We will move it back after
-	 * encryption.
-	 */
-	if ((x->props.flags & XFRM_STATE_ESN)) {
-		esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
-		*seqhi = esph->spi;
-		esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
-		aead_request_set_callback(req, 0, esp_output_done_esn, skb);
+	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
+	if (!tmp) {
+		err = -ENOMEM;
+		goto error;
 	}
 
-	esph->spi = x->id.spi;
+	seqhi = esp_tmp_seqhi(tmp);
+	iv = esp_tmp_iv(aead, tmp, seqhilen);
+	req = esp_tmp_req(aead, iv);
+	sg = esp_req_sg(aead, req);
+	dsg = sg;
+
+	esph = esp_output_set_esn(skb, esph, seqhi);
 
 	sg_init_table(sg, nfrags);
 	skb_to_sgvec(skb, sg,
 		     (unsigned char *)esph - skb->data,
 		     assoclen + ivlen + clen + alen);
 
-	aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
+skip_cow2:
+	if ((x->props.flags & XFRM_STATE_ESN))
+		aead_request_set_callback(req, 0, esp_output_done_esn, skb);
+	else
+		aead_request_set_callback(req, 0, esp_output_done, skb);
+
+	aead_request_set_crypt(req, sg, dsg, ivlen + clen, iv);
 	aead_request_set_ad(req, assoclen);
 
 	seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
@@ -278,6 +445,8 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
 			esp_output_restore_header(skb);
 	}
 
+	if (sg != dsg)
+		esp_ssg_unref(x, tmp);
 	kfree(tmp);
 
 error:
@@ -343,6 +512,23 @@ static void esp_input_restore_header(struct sk_buff *skb)
 	__skb_pull(skb, 4);
 }
 
+static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
+{
+	struct xfrm_state *x = xfrm_input_state(skb);
+	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data;
+
+	/* For ESN we move the header forward by 4 bytes to
+	 * accomodate the high bits.  We will move it back after
+	 * decryption.
+	 */
+	if ((x->props.flags & XFRM_STATE_ESN)) {
+		esph = (void *)skb_push(skb, 4);
+		*seqhi = esph->spi;
+		esph->spi = esph->seq_no;
+		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
+	}
+}
+
 static void esp_input_done_esn(struct crypto_async_request *base, int err)
 {
 	struct sk_buff *skb = base->data;
@@ -378,14 +564,6 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 		goto out;
 	}
 
-	nfrags = skb_cow_data(skb, 0, &trailer);
-	if (nfrags < 0) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = -ENOMEM;
-
 	assoclen = sizeof(*esph);
 	seqhilen = 0;
 
@@ -394,6 +572,27 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 		assoclen += seqhilen;
 	}
 
+	if (!skb_cloned(skb)) {
+		if (!skb_is_nonlinear(skb)) {
+			nfrags = 1;
+
+			goto skip_cow;
+		} else if (!skb_has_frag_list(skb)) {
+			nfrags = skb_shinfo(skb)->nr_frags;
+			nfrags++;
+
+			goto skip_cow;
+		}
+	}
+
+	nfrags = skb_cow_data(skb, 0, &trailer);
+	if (nfrags < 0) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+skip_cow:
+	ret = -ENOMEM;
 	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
 	if (!tmp)
 		goto out;
@@ -404,26 +603,17 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
 	req = esp_tmp_req(aead, iv);
 	sg = esp_req_sg(aead, req);
 
-	skb->ip_summed = CHECKSUM_NONE;
+	esp_input_set_header(skb, seqhi);
 
-	esph = (struct ip_esp_hdr *)skb->data;
+	sg_init_table(sg, nfrags);
+	skb_to_sgvec(skb, sg, 0, skb->len);
 
-	aead_request_set_callback(req, 0, esp_input_done, skb);
+	skb->ip_summed = CHECKSUM_NONE;
 
-	/* For ESN we move the header forward by 4 bytes to
-	 * accomodate the high bits.  We will move it back after
-	 * decryption.
-	 */
-	if ((x->props.flags & XFRM_STATE_ESN)) {
-		esph = (void *)skb_push(skb, 4);
-		*seqhi = esph->spi;
-		esph->spi = esph->seq_no;
-		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
+	if ((x->props.flags & XFRM_STATE_ESN))
 		aead_request_set_callback(req, 0, esp_input_done_esn, skb);
-	}
-
-	sg_init_table(sg, nfrags);
-	skb_to_sgvec(skb, sg, 0, skb->len);
+	else
+		aead_request_set_callback(req, 0, esp_input_done, skb);
 
 	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
 	aead_request_set_ad(req, assoclen);