// SPDX-License-Identifier: GPL-2.0-only
#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]))
/*
* 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