linux/net/ipv4/esp4.c
David S. Miller 2240c12d7d Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2018-10-01

1) Make xfrmi_get_link_net() static to silence a sparse warning.
   From Wei Yongjun.

2) Remove a unused esph pointer definition in esp_input().
   From Haishuang Yan.

3) Allow the NIC driver to quietly refuse xfrm offload
   in case it does not support it, the SA is created
   without offload in this case.
   From Shannon Nelson.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01 22:31:17 -07:00

1063 lines
24 KiB
C

#define pr_fmt(fmt) "IPsec: " fmt
#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <linux/scatterlist.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/in6.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/udp.h>
#include <linux/highmem.h>
struct esp_skb_cb {
struct xfrm_skb_cb xfrm;
void *tmp;
};
struct esp_output_extra {
__be32 seqhi;
u32 esphoff;
};
#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
/*
* Allocate an AEAD request structure with extra space for SG and IV.
*
* For alignment considerations the IV is placed at the front, followed
* by the request and finally the SG list.
*
* TODO: Use spare space in skb for this where possible.
*/
static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
{
unsigned int len;
len = extralen;
len += crypto_aead_ivsize(aead);
if (len) {
len += crypto_aead_alignmask(aead) &
~(crypto_tfm_ctx_alignment() - 1);
len = ALIGN(len, crypto_tfm_ctx_alignment());
}
len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
len = ALIGN(len, __alignof__(struct scatterlist));
len += sizeof(struct scatterlist) * nfrags;
return kmalloc(len, GFP_ATOMIC);
}
static inline void *esp_tmp_extra(void *tmp)
{
return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
}
static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
{
return crypto_aead_ivsize(aead) ?
PTR_ALIGN((u8 *)tmp + extralen,
crypto_aead_alignmask(aead) + 1) : tmp + extralen;
}
static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
{
struct aead_request *req;
req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
crypto_tfm_ctx_alignment());
aead_request_set_tfm(req, aead);
return req;
}
static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
struct aead_request *req)
{
return (void *)ALIGN((unsigned long)(req + 1) +
crypto_aead_reqsize(aead),
__alignof__(struct scatterlist));
}
static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
{
struct esp_output_extra *extra = esp_tmp_extra(tmp);
struct crypto_aead *aead = x->data;
int extralen = 0;
u8 *iv;
struct aead_request *req;
struct scatterlist *sg;
if (x->props.flags & XFRM_STATE_ESN)
extralen += sizeof(*extra);
extra = esp_tmp_extra(tmp);
iv = esp_tmp_iv(aead, tmp, extralen);
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;
struct xfrm_offload *xo = xfrm_offload(skb);
void *tmp;
struct xfrm_state *x;
if (xo && (xo->flags & XFRM_DEV_RESUME))
x = skb->sp->xvec[skb->sp->len - 1];
else
x = skb_dst(skb)->xfrm;
tmp = ESP_SKB_CB(skb)->tmp;
esp_ssg_unref(x, tmp);
kfree(tmp);
if (xo && (xo->flags & XFRM_DEV_RESUME)) {
if (err) {
XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
kfree_skb(skb);
return;
}
skb_push(skb, skb->data - skb_mac_header(skb));
secpath_reset(skb);
xfrm_dev_resume(skb);
} else {
xfrm_output_resume(skb, err);
}
}
/* Move ESP header back into place. */
static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
{
struct ip_esp_hdr *esph = (void *)(skb->data + offset);
void *tmp = ESP_SKB_CB(skb)->tmp;
__be32 *seqhi = esp_tmp_extra(tmp);
esph->seq_no = esph->spi;
esph->spi = *seqhi;
}
static void esp_output_restore_header(struct sk_buff *skb)
{
void *tmp = ESP_SKB_CB(skb)->tmp;
struct esp_output_extra *extra = esp_tmp_extra(tmp);
esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
sizeof(__be32));
}
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)
{
/* 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)) {
__u32 seqhi;
struct xfrm_offload *xo = xfrm_offload(skb);
if (xo)
seqhi = xo->seq.hi;
else
seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
extra->esphoff = (unsigned char *)esph -
skb_transport_header(skb);
esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
extra->seqhi = esph->spi;
esph->seq_no = htonl(seqhi);
}
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;
esp_output_restore_header(skb);
esp_output_done(base, err);
}
static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
{
/* 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;
}
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)
{
u8 *tail;
u8 *vaddr;
int nfrags;
int esph_offset;
struct page *page;
struct sk_buff *trailer;
int tailen = esp->tailen;
/* this is non-NULL only with UDP Encapsulation */
if (x->encap)
esp_output_udp_encap(x, skb, esp);
if (!skb_cloned(skb)) {
if (tailen <= skb_tailroom(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;
esp->inplace = false;
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;
esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->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;
spin_unlock_bh(&x->lock);
nfrags++;
skb->len += tailen;
skb->data_len += tailen;
skb->truesize += tailen;
if (sk)
refcount_add(tailen, &sk->sk_wmem_alloc);
goto out;
}
}
cow:
esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
nfrags = skb_cow_data(skb, tailen, &trailer);
if (nfrags < 0)
goto out;
tail = skb_tail_pointer(trailer);
esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
skip_cow:
esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
pskb_put(skb, trailer, tailen);
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);
}
aead = x->data;
alen = crypto_aead_authsize(aead);
ivlen = crypto_aead_ivsize(aead);
tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
if (!tmp)
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);
if (esp->inplace)
dsg = sg;
else
dsg = &sg[esp->nfrags];
esph = esp_output_set_extra(skb, x, esp->esph, extra);
esp->esph = esph;
sg_init_table(sg, esp->nfrags);
err = skb_to_sgvec(skb, sg,
(unsigned char *)esph - skb->data,
assoclen + ivlen + esp->clen + alen);
if (unlikely(err < 0))
goto error_free;
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);
goto error_free;
}
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);
err = skb_to_sgvec(skb, dsg,
(unsigned char *)esph - skb->data,
assoclen + ivlen + esp->clen + alen);
if (unlikely(err < 0))
goto error_free;
}
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 + esp->clen, iv);
aead_request_set_ad(req, assoclen);
memset(iv, 0, ivlen);
memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
min(ivlen, 8));
ESP_SKB_CB(skb)->tmp = tmp;
err = crypto_aead_encrypt(req);
switch (err) {
case -EINPROGRESS:
goto error;
case -ENOSPC:
err = NET_XMIT_DROP;
break;
case 0:
if ((x->props.flags & XFRM_STATE_ESN))
esp_output_restore_header(skb);
}
if (sg != dsg)
esp_ssg_unref(x, tmp);
error_free:
kfree(tmp);
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 inline int esp_remove_trailer(struct sk_buff *skb)
{
struct xfrm_state *x = xfrm_input_state(skb);
struct xfrm_offload *xo = xfrm_offload(skb);
struct crypto_aead *aead = x->data;
int alen, hlen, elen;
int padlen, trimlen;
__wsum csumdiff;
u8 nexthdr[2];
int ret;
alen = crypto_aead_authsize(aead);
hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
elen = skb->len - hlen;
if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
ret = xo->proto;
goto out;
}
if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
BUG();
ret = -EINVAL;
padlen = nexthdr[0];
if (padlen + 2 + alen >= elen) {
net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
padlen + 2, elen - alen);
goto out;
}
trimlen = alen + padlen + 2;
if (skb->ip_summed == CHECKSUM_COMPLETE) {
csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
skb->csum = csum_block_sub(skb->csum, csumdiff,
skb->len - trimlen);
}
pskb_trim(skb, skb->len - trimlen);
ret = nexthdr[1];
out:
return ret;
}
int esp_input_done2(struct sk_buff *skb, int err)
{
const struct iphdr *iph;
struct xfrm_state *x = xfrm_input_state(skb);
struct xfrm_offload *xo = xfrm_offload(skb);
struct crypto_aead *aead = x->data;
int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
int ihl;
if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
kfree(ESP_SKB_CB(skb)->tmp);
if (unlikely(err))
goto out;
err = esp_remove_trailer(skb);
if (unlikely(err < 0))
goto out;
iph = ip_hdr(skb);
ihl = iph->ihl * 4;
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
/*
* 1) if the NAT-T peer's IP or port changed then
* advertize the change to the keying daemon.
* This is an inbound SA, so just compare
* SRC ports.
*/
if (iph->saddr != x->props.saddr.a4 ||
uh->source != encap->encap_sport) {
xfrm_address_t ipaddr;
ipaddr.a4 = iph->saddr;
km_new_mapping(x, &ipaddr, uh->source);
/* XXX: perhaps add an extra
* policy check here, to see
* if we should allow or
* reject a packet from a
* different source
* address/port.
*/
}
/*
* 2) ignore UDP/TCP checksums in case
* of NAT-T in Transport Mode, or
* perform other post-processing fixes
* as per draft-ietf-ipsec-udp-encaps-06,
* section 3.1.2
*/
if (x->props.mode == XFRM_MODE_TRANSPORT)
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
skb_pull_rcsum(skb, hlen);
if (x->props.mode == XFRM_MODE_TUNNEL)
skb_reset_transport_header(skb);
else
skb_set_transport_header(skb, -ihl);
/* RFC4303: Drop dummy packets without any error */
if (err == IPPROTO_NONE)
err = -EINVAL;
out:
return err;
}
EXPORT_SYMBOL_GPL(esp_input_done2);
static void esp_input_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
xfrm_input_resume(skb, esp_input_done2(skb, err));
}
static void esp_input_restore_header(struct sk_buff *skb)
{
esp_restore_header(skb, 0);
__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;
/* 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 = 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;
esp_input_restore_header(skb);
esp_input_done(base, err);
}
/*
* Note: detecting truncated vs. non-truncated authentication data is very
* expensive, so we only support truncated data, which is the recommended
* and common case.
*/
static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct crypto_aead *aead = x->data;
struct aead_request *req;
struct sk_buff *trailer;
int ivlen = crypto_aead_ivsize(aead);
int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
int nfrags;
int assoclen;
int seqhilen;
__be32 *seqhi;
void *tmp;
u8 *iv;
struct scatterlist *sg;
int err = -EINVAL;
if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
goto out;
if (elen <= 0)
goto out;
assoclen = sizeof(struct ip_esp_hdr);
seqhilen = 0;
if (x->props.flags & XFRM_STATE_ESN) {
seqhilen += sizeof(__be32);
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;
}
}
err = skb_cow_data(skb, 0, &trailer);
if (err < 0)
goto out;
nfrags = err;
skip_cow:
err = -ENOMEM;
tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
if (!tmp)
goto out;
ESP_SKB_CB(skb)->tmp = tmp;
seqhi = esp_tmp_extra(tmp);
iv = esp_tmp_iv(aead, tmp, seqhilen);
req = esp_tmp_req(aead, iv);
sg = esp_req_sg(aead, req);
esp_input_set_header(skb, seqhi);
sg_init_table(sg, nfrags);
err = skb_to_sgvec(skb, sg, 0, skb->len);
if (unlikely(err < 0)) {
kfree(tmp);
goto out;
}
skb->ip_summed = CHECKSUM_NONE;
if ((x->props.flags & XFRM_STATE_ESN))
aead_request_set_callback(req, 0, esp_input_done_esn, skb);
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);
err = crypto_aead_decrypt(req);
if (err == -EINPROGRESS)
goto out;
if ((x->props.flags & XFRM_STATE_ESN))
esp_input_restore_header(skb);
err = esp_input_done2(skb, err);
out:
return err;
}
static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
{
struct crypto_aead *aead = x->data;
u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
unsigned int net_adj;
switch (x->props.mode) {
case XFRM_MODE_TRANSPORT:
case XFRM_MODE_BEET:
net_adj = sizeof(struct iphdr);
break;
case XFRM_MODE_TUNNEL:
net_adj = 0;
break;
default:
BUG();
}
return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
net_adj) & ~(blksize - 1)) + net_adj - 2;
}
static int esp4_err(struct sk_buff *skb, u32 info)
{
struct net *net = dev_net(skb->dev);
const struct iphdr *iph = (const struct iphdr *)skb->data;
struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
struct xfrm_state *x;
switch (icmp_hdr(skb)->type) {
case ICMP_DEST_UNREACH:
if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
return 0;
case ICMP_REDIRECT:
break;
default:
return 0;
}
x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
esph->spi, IPPROTO_ESP, AF_INET);
if (!x)
return 0;
if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
else
ipv4_redirect(skb, net, 0, IPPROTO_ESP);
xfrm_state_put(x);
return 0;
}
static void esp_destroy(struct xfrm_state *x)
{
struct crypto_aead *aead = x->data;
if (!aead)
return;
crypto_free_aead(aead);
}
static int esp_init_aead(struct xfrm_state *x)
{
char aead_name[CRYPTO_MAX_ALG_NAME];
struct crypto_aead *aead;
int err;
err = -ENAMETOOLONG;
if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
goto error;
aead = crypto_alloc_aead(aead_name, 0, 0);
err = PTR_ERR(aead);
if (IS_ERR(aead))
goto error;
x->data = aead;
err = crypto_aead_setkey(aead, x->aead->alg_key,
(x->aead->alg_key_len + 7) / 8);
if (err)
goto error;
err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
if (err)
goto error;
error:
return err;
}
static int esp_init_authenc(struct xfrm_state *x)
{
struct crypto_aead *aead;
struct crypto_authenc_key_param *param;
struct rtattr *rta;
char *key;
char *p;
char authenc_name[CRYPTO_MAX_ALG_NAME];
unsigned int keylen;
int err;
err = -EINVAL;
if (!x->ealg)
goto error;
err = -ENAMETOOLONG;
if ((x->props.flags & XFRM_STATE_ESN)) {
if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
"%s%sauthencesn(%s,%s)%s",
x->geniv ?: "", x->geniv ? "(" : "",
x->aalg ? x->aalg->alg_name : "digest_null",
x->ealg->alg_name,
x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
goto error;
} else {
if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
"%s%sauthenc(%s,%s)%s",
x->geniv ?: "", x->geniv ? "(" : "",
x->aalg ? x->aalg->alg_name : "digest_null",
x->ealg->alg_name,
x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
goto error;
}
aead = crypto_alloc_aead(authenc_name, 0, 0);
err = PTR_ERR(aead);
if (IS_ERR(aead))
goto error;
x->data = aead;
keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
(x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
err = -ENOMEM;
key = kmalloc(keylen, GFP_KERNEL);
if (!key)
goto error;
p = key;
rta = (void *)p;
rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
rta->rta_len = RTA_LENGTH(sizeof(*param));
param = RTA_DATA(rta);
p += RTA_SPACE(sizeof(*param));
if (x->aalg) {
struct xfrm_algo_desc *aalg_desc;
memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
p += (x->aalg->alg_key_len + 7) / 8;
aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
BUG_ON(!aalg_desc);
err = -EINVAL;
if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
crypto_aead_authsize(aead)) {
pr_info("ESP: %s digestsize %u != %hu\n",
x->aalg->alg_name,
crypto_aead_authsize(aead),
aalg_desc->uinfo.auth.icv_fullbits / 8);
goto free_key;
}
err = crypto_aead_setauthsize(
aead, x->aalg->alg_trunc_len / 8);
if (err)
goto free_key;
}
param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
err = crypto_aead_setkey(aead, key, keylen);
free_key:
kfree(key);
error:
return err;
}
static int esp_init_state(struct xfrm_state *x)
{
struct crypto_aead *aead;
u32 align;
int err;
x->data = NULL;
if (x->aead)
err = esp_init_aead(x);
else
err = esp_init_authenc(x);
if (err)
goto error;
aead = x->data;
x->props.header_len = sizeof(struct ip_esp_hdr) +
crypto_aead_ivsize(aead);
if (x->props.mode == XFRM_MODE_TUNNEL)
x->props.header_len += sizeof(struct iphdr);
else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
x->props.header_len += IPV4_BEET_PHMAXLEN;
if (x->encap) {
struct xfrm_encap_tmpl *encap = x->encap;
switch (encap->encap_type) {
default:
err = -EINVAL;
goto error;
case UDP_ENCAP_ESPINUDP:
x->props.header_len += sizeof(struct udphdr);
break;
case UDP_ENCAP_ESPINUDP_NON_IKE:
x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
break;
}
}
align = ALIGN(crypto_aead_blocksize(aead), 4);
x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
error:
return err;
}
static int esp4_rcv_cb(struct sk_buff *skb, int err)
{
return 0;
}
static const struct xfrm_type esp_type =
{
.description = "ESP4",
.owner = THIS_MODULE,
.proto = IPPROTO_ESP,
.flags = XFRM_TYPE_REPLAY_PROT,
.init_state = esp_init_state,
.destructor = esp_destroy,
.get_mtu = esp4_get_mtu,
.input = esp_input,
.output = esp_output,
};
static struct xfrm4_protocol esp4_protocol = {
.handler = xfrm4_rcv,
.input_handler = xfrm_input,
.cb_handler = esp4_rcv_cb,
.err_handler = esp4_err,
.priority = 0,
};
static int __init esp4_init(void)
{
if (xfrm_register_type(&esp_type, AF_INET) < 0) {
pr_info("%s: can't add xfrm type\n", __func__);
return -EAGAIN;
}
if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
pr_info("%s: can't add protocol\n", __func__);
xfrm_unregister_type(&esp_type, AF_INET);
return -EAGAIN;
}
return 0;
}
static void __exit esp4_fini(void)
{
if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
pr_info("%s: can't remove protocol\n", __func__);
if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
pr_info("%s: can't remove xfrm type\n", __func__);
}
module_init(esp4_init);
module_exit(esp4_fini);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);