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esp4: Reorganize esp_output

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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>
This commit is contained in:
Steffen Klassert 2017-04-14 10:06:33 +02:00
parent f1fbed0e89
commit fca11ebde3
3 changed files with 301 additions and 158 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

16
include/net/esp.h
View file

@ -10,4 +10,20 @@ static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb)
return (struct ip_esp_hdr *)skb_transport_header(skb); return (struct ip_esp_hdr *)skb_transport_header(skb);
} }
struct esp_info {
struct ip_esp_hdr *esph;
__be64 seqno;
int tfclen;
int tailen;
int plen;
int clen;
int len;
int nfrags;
__u8 proto;
bool inplace;
};
int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_input_done2(struct sk_buff *skb, int err);
#endif #endif

341
net/ipv4/esp4.c
View file

@ -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, static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
struct xfrm_state *x,
struct ip_esp_hdr *esph, struct ip_esp_hdr *esph,
struct esp_output_extra *extra) struct esp_output_extra *extra)
{ {
struct xfrm_state *x = skb_dst(skb)->xfrm;
/* For ESN we move the header forward by 4 bytes to /* For ESN we move the header forward by 4 bytes to
* accomodate the high bits. We will move it back after * accomodate the high bits. We will move it back after
* encryption. * encryption.
@ -198,98 +197,56 @@ static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
tail[plen - 1] = 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)
{
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;
}
*skb_mac_header(skb) = IPPROTO_UDP;
esp->esph = esph;
}
int esp_output_head(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 *tail;
u8 *vaddr; u8 *vaddr;
int blksize;
int clen;
int alen;
int plen;
int ivlen;
int tfclen;
int nfrags; int nfrags;
int assoclen; struct page *page;
int extralen; struct sk_buff *trailer;
int tailen; int tailen = esp->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;
}
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_ESP;
esph = ip_esp_hdr(skb);
/* this is non-NULL only with UDP Encapsulation */ /* this is non-NULL only with UDP Encapsulation */
if (x->encap) { if (x->encap)
struct xfrm_encap_tmpl *encap = x->encap; esp_output_udp_encap(x, skb, esp);
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 (!skb_cloned(skb)) { if (!skb_cloned(skb)) {
if (tailen <= skb_availroom(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 sock *sk = skb->sk;
struct page_frag *pfrag = &x->xfrag; struct page_frag *pfrag = &x->xfrag;
esp->inplace = false;
allocsize = ALIGN(tailen, L1_CACHE_BYTES); allocsize = ALIGN(tailen, L1_CACHE_BYTES);
spin_lock_bh(&x->lock); 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; 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); kunmap_atomic(vaddr);
spin_unlock_bh(&x->lock);
nfrags = skb_shinfo(skb)->nr_frags; nfrags = skb_shinfo(skb)->nr_frags;
__skb_fill_page_desc(skb, nfrags, page, pfrag->offset, __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) if (sk)
atomic_add(tailen, &sk->sk_wmem_alloc); atomic_add(tailen, &sk->sk_wmem_alloc);
skb_push(skb, -skb_network_offset(skb)); goto out;
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;
} }
} }
cow: cow:
err = skb_cow_data(skb, tailen, &trailer); nfrags = skb_cow_data(skb, tailen, &trailer);
if (err < 0) if (nfrags < 0)
goto error; goto out;
nfrags = err;
tail = skb_tail_pointer(trailer); tail = skb_tail_pointer(trailer);
esph = ip_esp_hdr(skb);
skip_cow: 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); out:
skb_push(skb, -skb_network_offset(skb)); return nfrags;
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); }
esph->spi = x->id.spi; EXPORT_SYMBOL_GPL(esp_output_head);
tmp = esp_alloc_tmp(aead, nfrags, extralen); 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);
}
aead = x->data;
alen = crypto_aead_authsize(aead);
ivlen = crypto_aead_ivsize(aead);
tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
if (!tmp) { if (!tmp) {
spin_unlock_bh(&x->lock);
err = -ENOMEM; err = -ENOMEM;
goto error; goto error;
} }
@ -417,26 +358,58 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
iv = esp_tmp_iv(aead, tmp, extralen); iv = esp_tmp_iv(aead, tmp, extralen);
req = esp_tmp_req(aead, iv); req = esp_tmp_req(aead, iv);
sg = esp_req_sg(aead, req); 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, skb_to_sgvec(skb, sg,
(unsigned char *)esph - skb->data, (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)) if ((x->props.flags & XFRM_STATE_ESN))
aead_request_set_callback(req, 0, esp_output_done_esn, skb); aead_request_set_callback(req, 0, esp_output_done_esn, skb);
else else
aead_request_set_callback(req, 0, esp_output_done, skb); 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); aead_request_set_ad(req, assoclen);
memset(iv, 0, ivlen); 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)); min(ivlen, 8));
ESP_SKB_CB(skb)->tmp = tmp; ESP_SKB_CB(skb)->tmp = tmp;
@ -462,8 +435,59 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
error: error:
return err; return err;
} }
EXPORT_SYMBOL_GPL(esp_output_tail);
static int esp_input_done2(struct sk_buff *skb, int err) 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);
}
int esp_input_done2(struct sk_buff *skb, int err)
{ {
const struct iphdr *iph; const struct iphdr *iph;
struct xfrm_state *x = xfrm_input_state(skb); struct xfrm_state *x = xfrm_input_state(skb);
@ -548,6 +572,7 @@ static int esp_input_done2(struct sk_buff *skb, int err)
out: out:
return err; return err;
} }
EXPORT_SYMBOL_GPL(esp_input_done2);
static void esp_input_done(struct crypto_async_request *base, int err) 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, .destructor = esp_destroy,
.get_mtu = esp4_get_mtu, .get_mtu = esp4_get_mtu,
.input = esp_input, .input = esp_input,
.output = esp_output .output = esp_output,
}; };
static struct xfrm4_protocol esp4_protocol = { static struct xfrm4_protocol esp4_protocol = {

102
net/ipv4/esp4_offload.c
View file

@ -84,19 +84,121 @@ static struct sk_buff **esp4_gro_receive(struct sk_buff **head,
return NULL; return NULL;
} }
static int esp_input_tail(struct xfrm_state *x, struct sk_buff *skb)
{
struct crypto_aead *aead = x->data;
if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead)))
return -EINVAL;
skb->ip_summed = CHECKSUM_NONE;
return esp_input_done2(skb, 0);
}
static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features)
{
int err;
int alen;
int blksize;
struct xfrm_offload *xo;
struct ip_esp_hdr *esph;
struct crypto_aead *aead;
struct esp_info esp;
bool hw_offload = true;
esp.inplace = true;
xo = xfrm_offload(skb);
if (!xo)
return -EINVAL;
if (!(features & NETIF_F_HW_ESP) ||
(x->xso.offload_handle && x->xso.dev != skb->dev)) {
xo->flags |= CRYPTO_FALLBACK;
hw_offload = false;
}
esp.proto = xo->proto;
/* skb is pure payload to encrypt */
aead = x->data;
alen = crypto_aead_authsize(aead);
esp.tfclen = 0;
/* XXX: Add support for tfc padding here. */
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);
if (!hw_offload || (hw_offload && !skb_is_gso(skb))) {
esp.nfrags = esp_output_head(x, skb, &esp);
if (esp.nfrags < 0)
return esp.nfrags;
}
esph = esp.esph;
esph->spi = x->id.spi;
skb_push(skb, -skb_network_offset(skb));
if (xo->flags & XFRM_GSO_SEGMENT) {
esph->seq_no = htonl(xo->seq.low);
} else {
ip_hdr(skb)->tot_len = htons(skb->len);
ip_send_check(ip_hdr(skb));
}
if (hw_offload)
return 0;
esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
err = esp_output_tail(x, skb, &esp);
if (err < 0)
return err;
secpath_reset(skb);
return 0;
}
static const struct net_offload esp4_offload = { static const struct net_offload esp4_offload = {
.callbacks = { .callbacks = {
.gro_receive = esp4_gro_receive, .gro_receive = esp4_gro_receive,
}, },
}; };
static const struct xfrm_type_offload esp_type_offload = {
.description = "ESP4 OFFLOAD",
.owner = THIS_MODULE,
.proto = IPPROTO_ESP,
.input_tail = esp_input_tail,
.xmit = esp_xmit,
};
static int __init esp4_offload_init(void) static int __init esp4_offload_init(void)
{ {
if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) {
pr_info("%s: can't add xfrm type offload\n", __func__);
return -EAGAIN;
}
return inet_add_offload(&esp4_offload, IPPROTO_ESP); return inet_add_offload(&esp4_offload, IPPROTO_ESP);
} }
static void __exit esp4_offload_exit(void) static void __exit esp4_offload_exit(void)
{ {
if (xfrm_unregister_type_offload(&esp_type_offload, AF_INET) < 0)
pr_info("%s: can't remove xfrm type offload\n", __func__);
inet_del_offload(&esp4_offload, IPPROTO_ESP); inet_del_offload(&esp4_offload, IPPROTO_ESP);
} }