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![Harvey Harrison](/assets/img/avatar_default.png)
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
593 lines
14 KiB
C
593 lines
14 KiB
C
/*
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* Copyright (C)2002 USAGI/WIDE Project
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Authors
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*
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* Mitsuru KANDA @USAGI : IPv6 Support
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* Kazunori MIYAZAWA @USAGI :
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* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
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*
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* This file is derived from net/ipv4/esp.c
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*/
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#include <crypto/aead.h>
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#include <crypto/authenc.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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#include <net/esp.h>
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#include <linux/scatterlist.h>
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#include <linux/kernel.h>
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#include <linux/pfkeyv2.h>
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#include <linux/random.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <net/icmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <linux/icmpv6.h>
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struct esp_skb_cb {
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struct xfrm_skb_cb xfrm;
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void *tmp;
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};
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#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
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/*
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* Allocate an AEAD request structure with extra space for SG and IV.
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*
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* For alignment considerations the IV is placed at the front, followed
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* by the request and finally the SG list.
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*
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* TODO: Use spare space in skb for this where possible.
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*/
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static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags)
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{
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unsigned int len;
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len = crypto_aead_ivsize(aead);
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if (len) {
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len += crypto_aead_alignmask(aead) &
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~(crypto_tfm_ctx_alignment() - 1);
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len = ALIGN(len, crypto_tfm_ctx_alignment());
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}
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len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
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len = ALIGN(len, __alignof__(struct scatterlist));
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len += sizeof(struct scatterlist) * nfrags;
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return kmalloc(len, GFP_ATOMIC);
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}
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static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp)
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{
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return crypto_aead_ivsize(aead) ?
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PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp;
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}
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static inline struct aead_givcrypt_request *esp_tmp_givreq(
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struct crypto_aead *aead, u8 *iv)
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{
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struct aead_givcrypt_request *req;
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req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
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crypto_tfm_ctx_alignment());
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aead_givcrypt_set_tfm(req, aead);
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return req;
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}
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static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
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{
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struct aead_request *req;
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req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
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crypto_tfm_ctx_alignment());
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aead_request_set_tfm(req, aead);
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return req;
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}
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static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
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struct aead_request *req)
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{
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return (void *)ALIGN((unsigned long)(req + 1) +
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crypto_aead_reqsize(aead),
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__alignof__(struct scatterlist));
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}
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static inline struct scatterlist *esp_givreq_sg(
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struct crypto_aead *aead, struct aead_givcrypt_request *req)
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{
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return (void *)ALIGN((unsigned long)(req + 1) +
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crypto_aead_reqsize(aead),
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__alignof__(struct scatterlist));
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}
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static void esp_output_done(struct crypto_async_request *base, int err)
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{
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struct sk_buff *skb = base->data;
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kfree(ESP_SKB_CB(skb)->tmp);
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xfrm_output_resume(skb, err);
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}
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static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err;
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struct ip_esp_hdr *esph;
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struct crypto_aead *aead;
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struct aead_givcrypt_request *req;
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struct scatterlist *sg;
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struct scatterlist *asg;
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struct sk_buff *trailer;
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void *tmp;
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int blksize;
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int clen;
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int alen;
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int nfrags;
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u8 *iv;
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u8 *tail;
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struct esp_data *esp = x->data;
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/* skb is pure payload to encrypt */
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err = -ENOMEM;
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/* Round to block size */
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clen = skb->len;
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aead = esp->aead;
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alen = crypto_aead_authsize(aead);
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blksize = ALIGN(crypto_aead_blocksize(aead), 4);
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clen = ALIGN(clen + 2, blksize);
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if (esp->padlen)
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clen = ALIGN(clen, esp->padlen);
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if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0)
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goto error;
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nfrags = err;
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tmp = esp_alloc_tmp(aead, nfrags + 1);
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if (!tmp)
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goto error;
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iv = esp_tmp_iv(aead, tmp);
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req = esp_tmp_givreq(aead, iv);
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asg = esp_givreq_sg(aead, req);
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sg = asg + 1;
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/* Fill padding... */
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tail = skb_tail_pointer(trailer);
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do {
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int i;
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for (i=0; i<clen-skb->len - 2; i++)
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tail[i] = i + 1;
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} while (0);
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tail[clen-skb->len - 2] = (clen - skb->len) - 2;
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tail[clen - skb->len - 1] = *skb_mac_header(skb);
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pskb_put(skb, trailer, clen - skb->len + alen);
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skb_push(skb, -skb_network_offset(skb));
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esph = ip_esp_hdr(skb);
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*skb_mac_header(skb) = IPPROTO_ESP;
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esph->spi = x->id.spi;
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esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
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sg_init_table(sg, nfrags);
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skb_to_sgvec(skb, sg,
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esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
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clen + alen);
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sg_init_one(asg, esph, sizeof(*esph));
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aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
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aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
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aead_givcrypt_set_assoc(req, asg, sizeof(*esph));
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aead_givcrypt_set_giv(req, esph->enc_data,
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XFRM_SKB_CB(skb)->seq.output);
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ESP_SKB_CB(skb)->tmp = tmp;
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err = crypto_aead_givencrypt(req);
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if (err == -EINPROGRESS)
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goto error;
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if (err == -EBUSY)
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err = NET_XMIT_DROP;
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kfree(tmp);
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error:
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return err;
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}
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static int esp_input_done2(struct sk_buff *skb, int err)
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{
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struct xfrm_state *x = xfrm_input_state(skb);
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struct esp_data *esp = x->data;
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struct crypto_aead *aead = esp->aead;
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int alen = crypto_aead_authsize(aead);
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int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
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int elen = skb->len - hlen;
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int hdr_len = skb_network_header_len(skb);
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int padlen;
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u8 nexthdr[2];
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kfree(ESP_SKB_CB(skb)->tmp);
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if (unlikely(err))
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goto out;
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if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
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BUG();
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err = -EINVAL;
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padlen = nexthdr[0];
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if (padlen + 2 + alen >= elen) {
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LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
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"padlen=%d, elen=%d\n", padlen + 2, elen - alen);
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goto out;
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}
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/* ... check padding bits here. Silly. :-) */
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pskb_trim(skb, skb->len - alen - padlen - 2);
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__skb_pull(skb, hlen);
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skb_set_transport_header(skb, -hdr_len);
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err = nexthdr[1];
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/* RFC4303: Drop dummy packets without any error */
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if (err == IPPROTO_NONE)
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err = -EINVAL;
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out:
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return err;
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}
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static void esp_input_done(struct crypto_async_request *base, int err)
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{
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struct sk_buff *skb = base->data;
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xfrm_input_resume(skb, esp_input_done2(skb, err));
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}
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static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct ip_esp_hdr *esph;
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struct esp_data *esp = x->data;
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struct crypto_aead *aead = esp->aead;
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struct aead_request *req;
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struct sk_buff *trailer;
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int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
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int nfrags;
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int ret = 0;
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void *tmp;
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u8 *iv;
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struct scatterlist *sg;
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struct scatterlist *asg;
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if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
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ret = -EINVAL;
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goto out;
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}
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if (elen <= 0) {
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ret = -EINVAL;
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goto out;
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}
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if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
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ret = -EINVAL;
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goto out;
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}
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ret = -ENOMEM;
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tmp = esp_alloc_tmp(aead, nfrags + 1);
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if (!tmp)
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goto out;
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ESP_SKB_CB(skb)->tmp = tmp;
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iv = esp_tmp_iv(aead, tmp);
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req = esp_tmp_req(aead, iv);
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asg = esp_req_sg(aead, req);
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sg = asg + 1;
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skb->ip_summed = CHECKSUM_NONE;
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esph = (struct ip_esp_hdr *)skb->data;
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/* Get ivec. This can be wrong, check against another impls. */
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iv = esph->enc_data;
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sg_init_table(sg, nfrags);
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skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
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sg_init_one(asg, esph, sizeof(*esph));
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aead_request_set_callback(req, 0, esp_input_done, skb);
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aead_request_set_crypt(req, sg, sg, elen, iv);
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aead_request_set_assoc(req, asg, sizeof(*esph));
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ret = crypto_aead_decrypt(req);
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if (ret == -EINPROGRESS)
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goto out;
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ret = esp_input_done2(skb, ret);
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out:
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return ret;
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}
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static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
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{
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struct esp_data *esp = x->data;
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u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
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u32 align = max_t(u32, blksize, esp->padlen);
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u32 rem;
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mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
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rem = mtu & (align - 1);
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mtu &= ~(align - 1);
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if (x->props.mode != XFRM_MODE_TUNNEL) {
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u32 padsize = ((blksize - 1) & 7) + 1;
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mtu -= blksize - padsize;
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mtu += min_t(u32, blksize - padsize, rem);
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}
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return mtu - 2;
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}
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static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
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int type, int code, int offset, __be32 info)
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{
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struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
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struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
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struct xfrm_state *x;
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if (type != ICMPV6_DEST_UNREACH &&
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type != ICMPV6_PKT_TOOBIG)
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return;
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x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
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if (!x)
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return;
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printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%pI6\n",
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ntohl(esph->spi), &iph->daddr);
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xfrm_state_put(x);
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}
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static void esp6_destroy(struct xfrm_state *x)
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{
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struct esp_data *esp = x->data;
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if (!esp)
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return;
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crypto_free_aead(esp->aead);
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kfree(esp);
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}
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static int esp_init_aead(struct xfrm_state *x)
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{
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struct esp_data *esp = x->data;
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struct crypto_aead *aead;
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int err;
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aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
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err = PTR_ERR(aead);
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if (IS_ERR(aead))
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goto error;
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esp->aead = aead;
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err = crypto_aead_setkey(aead, x->aead->alg_key,
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(x->aead->alg_key_len + 7) / 8);
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if (err)
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goto error;
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err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
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if (err)
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goto error;
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error:
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return err;
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}
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static int esp_init_authenc(struct xfrm_state *x)
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{
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struct esp_data *esp = x->data;
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struct crypto_aead *aead;
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struct crypto_authenc_key_param *param;
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struct rtattr *rta;
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char *key;
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char *p;
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char authenc_name[CRYPTO_MAX_ALG_NAME];
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unsigned int keylen;
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int err;
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err = -EINVAL;
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if (x->ealg == NULL)
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goto error;
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err = -ENAMETOOLONG;
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if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)",
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x->aalg ? x->aalg->alg_name : "digest_null",
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x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
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goto error;
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aead = crypto_alloc_aead(authenc_name, 0, 0);
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err = PTR_ERR(aead);
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if (IS_ERR(aead))
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goto error;
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esp->aead = aead;
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keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
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(x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
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err = -ENOMEM;
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key = kmalloc(keylen, GFP_KERNEL);
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if (!key)
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goto error;
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p = key;
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rta = (void *)p;
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rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
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rta->rta_len = RTA_LENGTH(sizeof(*param));
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param = RTA_DATA(rta);
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p += RTA_SPACE(sizeof(*param));
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if (x->aalg) {
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struct xfrm_algo_desc *aalg_desc;
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memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
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p += (x->aalg->alg_key_len + 7) / 8;
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aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
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BUG_ON(!aalg_desc);
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err = -EINVAL;
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if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
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crypto_aead_authsize(aead)) {
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NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
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x->aalg->alg_name,
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crypto_aead_authsize(aead),
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aalg_desc->uinfo.auth.icv_fullbits/8);
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goto free_key;
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}
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err = crypto_aead_setauthsize(
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aead, aalg_desc->uinfo.auth.icv_truncbits / 8);
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if (err)
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goto free_key;
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}
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param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
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memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
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err = crypto_aead_setkey(aead, key, keylen);
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free_key:
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kfree(key);
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error:
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return err;
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}
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static int esp6_init_state(struct xfrm_state *x)
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{
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struct esp_data *esp;
|
|
struct crypto_aead *aead;
|
|
u32 align;
|
|
int err;
|
|
|
|
if (x->encap)
|
|
return -EINVAL;
|
|
|
|
esp = kzalloc(sizeof(*esp), GFP_KERNEL);
|
|
if (esp == NULL)
|
|
return -ENOMEM;
|
|
|
|
x->data = esp;
|
|
|
|
if (x->aead)
|
|
err = esp_init_aead(x);
|
|
else
|
|
err = esp_init_authenc(x);
|
|
|
|
if (err)
|
|
goto error;
|
|
|
|
aead = esp->aead;
|
|
|
|
esp->padlen = 0;
|
|
|
|
x->props.header_len = sizeof(struct ip_esp_hdr) +
|
|
crypto_aead_ivsize(aead);
|
|
switch (x->props.mode) {
|
|
case XFRM_MODE_BEET:
|
|
if (x->sel.family != AF_INET6)
|
|
x->props.header_len += IPV4_BEET_PHMAXLEN +
|
|
(sizeof(struct ipv6hdr) - sizeof(struct iphdr));
|
|
break;
|
|
case XFRM_MODE_TRANSPORT:
|
|
break;
|
|
case XFRM_MODE_TUNNEL:
|
|
x->props.header_len += sizeof(struct ipv6hdr);
|
|
break;
|
|
default:
|
|
goto error;
|
|
}
|
|
|
|
align = ALIGN(crypto_aead_blocksize(aead), 4);
|
|
if (esp->padlen)
|
|
align = max_t(u32, align, esp->padlen);
|
|
x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
|
|
|
|
error:
|
|
return err;
|
|
}
|
|
|
|
static const struct xfrm_type esp6_type =
|
|
{
|
|
.description = "ESP6",
|
|
.owner = THIS_MODULE,
|
|
.proto = IPPROTO_ESP,
|
|
.flags = XFRM_TYPE_REPLAY_PROT,
|
|
.init_state = esp6_init_state,
|
|
.destructor = esp6_destroy,
|
|
.get_mtu = esp6_get_mtu,
|
|
.input = esp6_input,
|
|
.output = esp6_output,
|
|
.hdr_offset = xfrm6_find_1stfragopt,
|
|
};
|
|
|
|
static struct inet6_protocol esp6_protocol = {
|
|
.handler = xfrm6_rcv,
|
|
.err_handler = esp6_err,
|
|
.flags = INET6_PROTO_NOPOLICY,
|
|
};
|
|
|
|
static int __init esp6_init(void)
|
|
{
|
|
if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
|
|
printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
|
|
return -EAGAIN;
|
|
}
|
|
if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
|
|
printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
|
|
xfrm_unregister_type(&esp6_type, AF_INET6);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit esp6_fini(void)
|
|
{
|
|
if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
|
|
printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
|
|
if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
|
|
printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
|
|
}
|
|
|
|
module_init(esp6_init);
|
|
module_exit(esp6_fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
|