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authorSteffen Klassert <steffen.klassert@secunet.com>2017-04-14 10:06:33 +0200
committerSteffen Klassert <steffen.klassert@secunet.com>2017-04-14 10:06:33 +0200
commitfca11ebde3f0d1c637550a9b231caa385ce35749 (patch)
tree52b18ae170138ecbdd2dbfd7d1add335d4e5c0af /net/ipv4/esp4.c
parentf1fbed0e89303e6100085ea1dfb25d8413ca06ec (diff)
downloadlinux-fca11ebde3f0d1c637550a9b231caa385ce35749.tar.bz2
esp4: Reorganize esp_output
We need a fallback for ESP at layer 2, so split esp_output into generic functions that can be used at layer 3 and layer 2 and use them in esp_output. We also add esp_xmit which is used for the layer 2 fallback. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/ipv4/esp4.c')
-rw-r--r--net/ipv4/esp4.c341
1 files changed, 183 insertions, 158 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index c6aba234b6e9..91e6a402e22e 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -152,11 +152,10 @@ static void esp_output_restore_header(struct sk_buff *skb)
}
static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
+ struct xfrm_state *x,
struct ip_esp_hdr *esph,
struct esp_output_extra *extra)
{
- 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.
@@ -198,98 +197,56 @@ static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
tail[plen - 1] = proto;
}
-static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
+static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
{
- struct esp_output_extra *extra;
- int err = -ENOMEM;
- struct ip_esp_hdr *esph;
- struct crypto_aead *aead;
- struct aead_request *req;
- struct scatterlist *sg, *dsg;
- struct sk_buff *trailer;
- struct page *page;
- void *tmp;
- u8 *iv;
- u8 *tail;
- u8 *vaddr;
- int blksize;
- int clen;
- int alen;
- int plen;
- int ivlen;
- int tfclen;
- int nfrags;
- int assoclen;
- int extralen;
- int tailen;
- __be64 seqno;
- __u8 proto = *skb_mac_header(skb);
-
- /* skb is pure payload to encrypt */
-
- aead = x->data;
- alen = crypto_aead_authsize(aead);
- ivlen = crypto_aead_ivsize(aead);
-
- tfclen = 0;
- if (x->tfcpad) {
- struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
- u32 padto;
-
- padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
- if (skb->len < padto)
- tfclen = padto - skb->len;
+ int encap_type;
+ struct udphdr *uh;
+ __be32 *udpdata32;
+ __be16 sport, dport;
+ struct xfrm_encap_tmpl *encap = x->encap;
+ struct ip_esp_hdr *esph = esp->esph;
+
+ spin_lock_bh(&x->lock);
+ sport = encap->encap_sport;
+ dport = encap->encap_dport;
+ encap_type = encap->encap_type;
+ spin_unlock_bh(&x->lock);
+
+ uh = (struct udphdr *)esph;
+ uh->source = sport;
+ uh->dest = dport;
+ uh->len = htons(skb->len + esp->tailen
+ - skb_transport_offset(skb));
+ uh->check = 0;
+
+ switch (encap_type) {
+ default:
+ case UDP_ENCAP_ESPINUDP:
+ esph = (struct ip_esp_hdr *)(uh + 1);
+ break;
+ case UDP_ENCAP_ESPINUDP_NON_IKE:
+ udpdata32 = (__be32 *)(uh + 1);
+ udpdata32[0] = udpdata32[1] = 0;
+ esph = (struct ip_esp_hdr *)(udpdata32 + 2);
+ break;
}
- blksize = ALIGN(crypto_aead_blocksize(aead), 4);
- clen = ALIGN(skb->len + 2 + tfclen, blksize);
- plen = clen - skb->len - tfclen;
- tailen = tfclen + plen + alen;
- assoclen = sizeof(*esph);
- extralen = 0;
- if (x->props.flags & XFRM_STATE_ESN) {
- extralen += sizeof(*extra);
- assoclen += sizeof(__be32);
- }
+ *skb_mac_header(skb) = IPPROTO_UDP;
+ esp->esph = esph;
+}
- *skb_mac_header(skb) = IPPROTO_ESP;
- esph = ip_esp_hdr(skb);
+int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
+{
+ u8 *tail;
+ u8 *vaddr;
+ int nfrags;
+ struct page *page;
+ struct sk_buff *trailer;
+ int tailen = esp->tailen;
/* this is non-NULL only with UDP Encapsulation */
- if (x->encap) {
- struct xfrm_encap_tmpl *encap = x->encap;
- struct udphdr *uh;
- __be32 *udpdata32;
- __be16 sport, dport;
- int encap_type;
-
- spin_lock_bh(&x->lock);
- sport = encap->encap_sport;
- dport = encap->encap_dport;
- encap_type = encap->encap_type;
- spin_unlock_bh(&x->lock);
-
- uh = (struct udphdr *)esph;
- uh->source = sport;
- uh->dest = dport;
- uh->len = htons(skb->len + tailen
- - skb_transport_offset(skb));
- uh->check = 0;
-
- switch (encap_type) {
- default:
- case UDP_ENCAP_ESPINUDP:
- esph = (struct ip_esp_hdr *)(uh + 1);
- break;
- case UDP_ENCAP_ESPINUDP_NON_IKE:
- udpdata32 = (__be32 *)(uh + 1);
- udpdata32[0] = udpdata32[1] = 0;
- esph = (struct ip_esp_hdr *)(udpdata32 + 2);
- break;
- }
-
- *skb_mac_header(skb) = IPPROTO_UDP;
- }
+ if (x->encap)
+ esp_output_udp_encap(x, skb, esp);
if (!skb_cloned(skb)) {
if (tailen <= skb_availroom(skb)) {
@@ -304,6 +261,8 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
struct sock *sk = skb->sk;
struct page_frag *pfrag = &x->xfrag;
+ esp->inplace = false;
+
allocsize = ALIGN(tailen, L1_CACHE_BYTES);
spin_lock_bh(&x->lock);
@@ -320,10 +279,12 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
tail = vaddr + pfrag->offset;
- esp_output_fill_trailer(tail, tfclen, plen, proto);
+ esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
kunmap_atomic(vaddr);
+ spin_unlock_bh(&x->lock);
+
nfrags = skb_shinfo(skb)->nr_frags;
__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
@@ -339,76 +300,56 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
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, extralen);
- if (!tmp) {
- spin_unlock_bh(&x->lock);
- err = -ENOMEM;
- goto error;
- }
-
- extra = esp_tmp_extra(tmp);
- iv = esp_tmp_iv(aead, tmp, extralen);
- req = esp_tmp_req(aead, iv);
- sg = esp_req_sg(aead, req);
- dsg = &sg[nfrags];
-
- esph = esp_output_set_extra(skb, esph, extra);
-
- 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;
+ goto out;
}
}
cow:
- err = skb_cow_data(skb, tailen, &trailer);
- if (err < 0)
- goto error;
- nfrags = err;
+ nfrags = skb_cow_data(skb, tailen, &trailer);
+ if (nfrags < 0)
+ goto out;
tail = skb_tail_pointer(trailer);
- esph = ip_esp_hdr(skb);
skip_cow:
- esp_output_fill_trailer(tail, tfclen, plen, proto);
+ esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
+ pskb_put(skb, trailer, tailen);
- pskb_put(skb, trailer, clen - skb->len + alen);
- skb_push(skb, -skb_network_offset(skb));
- esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
- esph->spi = x->id.spi;
+out:
+ return nfrags;
+}
+EXPORT_SYMBOL_GPL(esp_output_head);
+
+int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
+{
+ u8 *iv;
+ int alen;
+ void *tmp;
+ int ivlen;
+ int assoclen;
+ int extralen;
+ struct page *page;
+ struct ip_esp_hdr *esph;
+ struct crypto_aead *aead;
+ struct aead_request *req;
+ struct scatterlist *sg, *dsg;
+ struct esp_output_extra *extra;
+ int err = -ENOMEM;
+
+ assoclen = sizeof(struct ip_esp_hdr);
+ extralen = 0;
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ extralen += sizeof(*extra);
+ assoclen += sizeof(__be32);
+ }
- tmp = esp_alloc_tmp(aead, nfrags, extralen);
+ aead = x->data;
+ alen = crypto_aead_authsize(aead);
+ ivlen = crypto_aead_ivsize(aead);
+
+ tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
if (!tmp) {
+ spin_unlock_bh(&x->lock);
err = -ENOMEM;
goto error;
}
@@ -417,26 +358,58 @@ skip_cow:
iv = esp_tmp_iv(aead, tmp, extralen);
req = esp_tmp_req(aead, iv);
sg = esp_req_sg(aead, req);
- dsg = sg;
- esph = esp_output_set_extra(skb, esph, extra);
+ if (esp->inplace)
+ dsg = sg;
+ else
+ dsg = &sg[esp->nfrags];
- sg_init_table(sg, nfrags);
+ esph = esp_output_set_extra(skb, x, esp->esph, extra);
+ esp->esph = esph;
+
+ sg_init_table(sg, esp->nfrags);
skb_to_sgvec(skb, sg,
(unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ assoclen + ivlen + esp->clen + alen);
+
+ if (!esp->inplace) {
+ int allocsize;
+ struct page_frag *pfrag = &x->xfrag;
+
+ allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
+
+ spin_lock_bh(&x->lock);
+ 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;
+ spin_unlock_bh(&x->lock);
+
+ sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
+ skb_to_sgvec(skb, dsg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + esp->clen + alen);
+ }
-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_crypt(req, sg, dsg, ivlen + esp->clen, iv);
aead_request_set_ad(req, assoclen);
memset(iv, 0, ivlen);
- memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
+ memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
min(ivlen, 8));
ESP_SKB_CB(skb)->tmp = tmp;
@@ -462,8 +435,59 @@ skip_cow2:
error:
return err;
}
+EXPORT_SYMBOL_GPL(esp_output_tail);
+
+static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int alen;
+ int blksize;
+ struct ip_esp_hdr *esph;
+ struct crypto_aead *aead;
+ struct esp_info esp;
+
+ esp.inplace = true;
+
+ esp.proto = *skb_mac_header(skb);
+ *skb_mac_header(skb) = IPPROTO_ESP;
+
+ /* skb is pure payload to encrypt */
+
+ aead = x->data;
+ alen = crypto_aead_authsize(aead);
+
+ esp.tfclen = 0;
+ if (x->tfcpad) {
+ struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
+ u32 padto;
+
+ padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
+ if (skb->len < padto)
+ esp.tfclen = padto - skb->len;
+ }
+ blksize = ALIGN(crypto_aead_blocksize(aead), 4);
+ esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
+ esp.plen = esp.clen - skb->len - esp.tfclen;
+ esp.tailen = esp.tfclen + esp.plen + alen;
+
+ esp.esph = ip_esp_hdr(skb);
+
+ esp.nfrags = esp_output_head(x, skb, &esp);
+ if (esp.nfrags < 0)
+ return esp.nfrags;
+
+ esph = esp.esph;
+ esph->spi = x->id.spi;
+
+ esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+ esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
+ ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
+
+ skb_push(skb, -skb_network_offset(skb));
+
+ return esp_output_tail(x, skb, &esp);
+}
-static int esp_input_done2(struct sk_buff *skb, int err)
+int esp_input_done2(struct sk_buff *skb, int err)
{
const struct iphdr *iph;
struct xfrm_state *x = xfrm_input_state(skb);
@@ -548,6 +572,7 @@ static int esp_input_done2(struct sk_buff *skb, int err)
out:
return err;
}
+EXPORT_SYMBOL_GPL(esp_input_done2);
static void esp_input_done(struct crypto_async_request *base, int err)
{
@@ -930,7 +955,7 @@ static const struct xfrm_type esp_type =
.destructor = esp_destroy,
.get_mtu = esp4_get_mtu,
.input = esp_input,
- .output = esp_output
+ .output = esp_output,
};
static struct xfrm4_protocol esp4_protocol = {