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klassertklassert
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esp6: Reorganize esp_output
We need a fallback for ESP at layer 2, so split esp6_output into generic functions that can be used at layer 3 and layer 2 and use them in esp_output. We also add esp6_xmit which is used for the layer 2 fallback. Signed-off-by: Steffen Klassert <[email protected]>
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3 files changed

+246
-124
lines changed

3 files changed

+246
-124
lines changed

‎include/net/esp.h‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -26,4 +26,7 @@ struct esp_info {
2626
int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
2727
int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
2828
int esp_input_done2(struct sk_buff *skb, int err);
29+
int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
30+
int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
31+
int esp6_input_done2(struct sk_buff *skb, int err);
2932
#endif

‎net/ipv6/esp6.c‎

Lines changed: 140 additions & 124 deletions
Original file line numberDiff line numberDiff line change
@@ -170,11 +170,10 @@ static void esp_output_restore_header(struct sk_buff *skb)
170170
}
171171

172172
static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
173+
struct xfrm_state *x,
173174
struct ip_esp_hdr *esph,
174175
__be32 *seqhi)
175176
{
176-
struct xfrm_state *x = skb_dst(skb)->xfrm;
177-
178177
/* For ESN we move the header forward by 4 bytes to
179178
* accomodate the high bits. We will move it back after
180179
* encryption.
@@ -214,59 +213,15 @@ static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
214213
tail[plen - 1] = proto;
215214
}
216215

217-
static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
216+
int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
218217
{
219-
int err;
220-
struct ip_esp_hdr *esph;
221-
struct crypto_aead *aead;
222-
struct aead_request *req;
223-
struct scatterlist *sg, *dsg;
224-
struct sk_buff *trailer;
225-
struct page *page;
226-
void *tmp;
227-
int blksize;
228-
int clen;
229-
int alen;
230-
int plen;
231-
int ivlen;
232-
int tfclen;
233-
int nfrags;
234-
int assoclen;
235-
int seqhilen;
236-
int tailen;
237-
u8 *iv;
238218
u8 *tail;
239219
u8 *vaddr;
240-
__be32 *seqhi;
241-
__be64 seqno;
242-
__u8 proto = *skb_mac_header(skb);
243-
244-
/* skb is pure payload to encrypt */
245-
aead = x->data;
246-
alen = crypto_aead_authsize(aead);
247-
ivlen = crypto_aead_ivsize(aead);
248-
249-
tfclen = 0;
250-
if (x->tfcpad) {
251-
struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
252-
u32 padto;
253-
254-
padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
255-
if (skb->len < padto)
256-
tfclen = padto - skb->len;
257-
}
258-
blksize = ALIGN(crypto_aead_blocksize(aead), 4);
259-
clen = ALIGN(skb->len + 2 + tfclen, blksize);
260-
plen = clen - skb->len - tfclen;
261-
tailen = tfclen + plen + alen;
262-
263-
assoclen = sizeof(*esph);
264-
seqhilen = 0;
265-
266-
if (x->props.flags & XFRM_STATE_ESN) {
267-
seqhilen += sizeof(__be32);
268-
assoclen += seqhilen;
269-
}
220+
int nfrags;
221+
struct page *page;
222+
struct ip_esp_hdr *esph;
223+
struct sk_buff *trailer;
224+
int tailen = esp->tailen;
270225

271226
*skb_mac_header(skb) = IPPROTO_ESP;
272227
esph = ip_esp_hdr(skb);
@@ -284,6 +239,8 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
284239
struct sock *sk = skb->sk;
285240
struct page_frag *pfrag = &x->xfrag;
286241

242+
esp->inplace = false;
243+
287244
allocsize = ALIGN(tailen, L1_CACHE_BYTES);
288245

289246
spin_lock_bh(&x->lock);
@@ -300,10 +257,12 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
300257

301258
tail = vaddr + pfrag->offset;
302259

303-
esp_output_fill_trailer(tail, tfclen, plen, proto);
260+
esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
304261

305262
kunmap_atomic(vaddr);
306263

264+
spin_unlock_bh(&x->lock);
265+
307266
nfrags = skb_shinfo(skb)->nr_frags;
308267

309268
__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
@@ -319,77 +278,56 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
319278
if (sk)
320279
atomic_add(tailen, &sk->sk_wmem_alloc);
321280

322-
skb_push(skb, -skb_network_offset(skb));
323-
324-
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
325-
esph->spi = x->id.spi;
326-
327-
tmp = esp_alloc_tmp(aead, nfrags + 2, seqhilen);
328-
if (!tmp) {
329-
spin_unlock_bh(&x->lock);
330-
err = -ENOMEM;
331-
goto error;
332-
}
333-
seqhi = esp_tmp_seqhi(tmp);
334-
iv = esp_tmp_iv(aead, tmp, seqhilen);
335-
req = esp_tmp_req(aead, iv);
336-
sg = esp_req_sg(aead, req);
337-
dsg = &sg[nfrags];
338-
339-
esph = esp_output_set_esn(skb, esph, seqhi);
340-
341-
sg_init_table(sg, nfrags);
342-
skb_to_sgvec(skb, sg,
343-
(unsigned char *)esph - skb->data,
344-
assoclen + ivlen + clen + alen);
345-
346-
allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
347-
348-
if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
349-
spin_unlock_bh(&x->lock);
350-
err = -ENOMEM;
351-
goto error;
352-
}
353-
354-
skb_shinfo(skb)->nr_frags = 1;
355-
356-
page = pfrag->page;
357-
get_page(page);
358-
/* replace page frags in skb with new page */
359-
__skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
360-
pfrag->offset = pfrag->offset + allocsize;
361-
362-
sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
363-
skb_to_sgvec(skb, dsg,
364-
(unsigned char *)esph - skb->data,
365-
assoclen + ivlen + clen + alen);
366-
367-
spin_unlock_bh(&x->lock);
368-
369-
goto skip_cow2;
281+
goto out;
370282
}
371283
}
372284

373285
cow:
374-
err = skb_cow_data(skb, tailen, &trailer);
375-
if (err < 0)
376-
goto error;
377-
nfrags = err;
378-
286+
nfrags = skb_cow_data(skb, tailen, &trailer);
287+
if (nfrags < 0)
288+
goto out;
379289
tail = skb_tail_pointer(trailer);
380-
esph = ip_esp_hdr(skb);
381290

382291
skip_cow:
383-
esp_output_fill_trailer(tail, tfclen, plen, proto);
292+
esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
293+
pskb_put(skb, trailer, tailen);
384294

385-
pskb_put(skb, trailer, clen - skb->len + alen);
386-
skb_push(skb, -skb_network_offset(skb));
295+
out:
296+
return nfrags;
297+
}
298+
EXPORT_SYMBOL_GPL(esp6_output_head);
387299

388-
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
389-
esph->spi = x->id.spi;
300+
int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
301+
{
302+
u8 *iv;
303+
int alen;
304+
void *tmp;
305+
int ivlen;
306+
int assoclen;
307+
int seqhilen;
308+
__be32 *seqhi;
309+
struct page *page;
310+
struct ip_esp_hdr *esph;
311+
struct aead_request *req;
312+
struct crypto_aead *aead;
313+
struct scatterlist *sg, *dsg;
314+
int err = -ENOMEM;
390315

391-
tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
316+
assoclen = sizeof(struct ip_esp_hdr);
317+
seqhilen = 0;
318+
319+
if (x->props.flags & XFRM_STATE_ESN) {
320+
seqhilen += sizeof(__be32);
321+
assoclen += sizeof(__be32);
322+
}
323+
324+
aead = x->data;
325+
alen = crypto_aead_authsize(aead);
326+
ivlen = crypto_aead_ivsize(aead);
327+
328+
tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
392329
if (!tmp) {
330+
spin_unlock_bh(&x->lock);
393331
err = -ENOMEM;
394332
goto error;
395333
}
@@ -398,29 +336,57 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
398336
iv = esp_tmp_iv(aead, tmp, seqhilen);
399337
req = esp_tmp_req(aead, iv);
400338
sg = esp_req_sg(aead, req);
401-
dsg = sg;
402339

403-
esph = esp_output_set_esn(skb, esph, seqhi);
340+
if (esp->inplace)
341+
dsg = sg;
342+
else
343+
dsg = &sg[esp->nfrags];
404344

405-
sg_init_table(sg, nfrags);
345+
esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
346+
347+
sg_init_table(sg, esp->nfrags);
406348
skb_to_sgvec(skb, sg,
407349
(unsigned char *)esph - skb->data,
408-
assoclen + ivlen + clen + alen);
350+
assoclen + ivlen + esp->clen + alen);
351+
352+
if (!esp->inplace) {
353+
int allocsize;
354+
struct page_frag *pfrag = &x->xfrag;
355+
356+
allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
357+
358+
spin_lock_bh(&x->lock);
359+
if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
360+
spin_unlock_bh(&x->lock);
361+
err = -ENOMEM;
362+
goto error;
363+
}
364+
365+
skb_shinfo(skb)->nr_frags = 1;
366+
367+
page = pfrag->page;
368+
get_page(page);
369+
/* replace page frags in skb with new page */
370+
__skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
371+
pfrag->offset = pfrag->offset + allocsize;
372+
spin_unlock_bh(&x->lock);
373+
374+
sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
375+
skb_to_sgvec(skb, dsg,
376+
(unsigned char *)esph - skb->data,
377+
assoclen + ivlen + esp->clen + alen);
378+
}
409379

410-
skip_cow2:
411380
if ((x->props.flags & XFRM_STATE_ESN))
412381
aead_request_set_callback(req, 0, esp_output_done_esn, skb);
413382
else
414383
aead_request_set_callback(req, 0, esp_output_done, skb);
415384

416-
aead_request_set_crypt(req, sg, dsg, ivlen + clen, iv);
385+
aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
417386
aead_request_set_ad(req, assoclen);
418387

419-
seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
420-
((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
421-
422388
memset(iv, 0, ivlen);
423-
memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
389+
memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
424390
min(ivlen, 8));
425391

426392
ESP_SKB_CB(skb)->tmp = tmp;
@@ -446,8 +412,57 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
446412
error:
447413
return err;
448414
}
415+
EXPORT_SYMBOL_GPL(esp6_output_tail);
416+
417+
static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
418+
{
419+
int alen;
420+
int blksize;
421+
struct ip_esp_hdr *esph;
422+
struct crypto_aead *aead;
423+
struct esp_info esp;
424+
425+
esp.inplace = true;
426+
427+
esp.proto = *skb_mac_header(skb);
428+
*skb_mac_header(skb) = IPPROTO_ESP;
429+
430+
/* skb is pure payload to encrypt */
431+
432+
aead = x->data;
433+
alen = crypto_aead_authsize(aead);
434+
435+
esp.tfclen = 0;
436+
if (x->tfcpad) {
437+
struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
438+
u32 padto;
439+
440+
padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
441+
if (skb->len < padto)
442+
esp.tfclen = padto - skb->len;
443+
}
444+
blksize = ALIGN(crypto_aead_blocksize(aead), 4);
445+
esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
446+
esp.plen = esp.clen - skb->len - esp.tfclen;
447+
esp.tailen = esp.tfclen + esp.plen + alen;
448+
449+
esp.nfrags = esp6_output_head(x, skb, &esp);
450+
if (esp.nfrags < 0)
451+
return esp.nfrags;
452+
453+
esph = ip_esp_hdr(skb);
454+
esph->spi = x->id.spi;
455+
456+
esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
457+
esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
458+
((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
459+
460+
skb_push(skb, -skb_network_offset(skb));
461+
462+
return esp6_output_tail(x, skb, &esp);
463+
}
449464

450-
static int esp6_input_done2(struct sk_buff *skb, int err)
465+
int esp6_input_done2(struct sk_buff *skb, int err)
451466
{
452467
struct xfrm_state *x = xfrm_input_state(skb);
453468
struct xfrm_offload *xo = xfrm_offload(skb);
@@ -494,6 +509,7 @@ static int esp6_input_done2(struct sk_buff *skb, int err)
494509
out:
495510
return err;
496511
}
512+
EXPORT_SYMBOL_GPL(esp6_input_done2);
497513

498514
static void esp_input_done(struct crypto_async_request *base, int err)
499515
{

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