2005-04-17 00:20:36 +02:00
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/*
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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 <linux/config.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 <asm/scatterlist.h>
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#include <linux/crypto.h>
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2005-10-11 06:11:08 +02:00
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#include <linux/kernel.h>
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2005-04-17 00:20:36 +02:00
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#include <linux/pfkeyv2.h>
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#include <linux/random.h>
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#include <net/icmp.h>
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#include <net/ipv6.h>
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2005-12-27 05:43:12 +01:00
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#include <net/protocol.h>
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2005-04-17 00:20:36 +02:00
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#include <linux/icmpv6.h>
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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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int hdr_len;
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struct ipv6hdr *top_iph;
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struct ipv6_esp_hdr *esph;
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struct crypto_tfm *tfm;
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struct esp_data *esp;
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struct sk_buff *trailer;
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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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esp = x->data;
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hdr_len = skb->h.raw - skb->data +
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sizeof(*esph) + esp->conf.ivlen;
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/* Strip IP+ESP header. */
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__skb_pull(skb, hdr_len);
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/* Now 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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alen = esp->auth.icv_trunc_len;
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tfm = esp->conf.tfm;
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2005-10-11 06:11:08 +02:00
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blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
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clen = ALIGN(clen + 2, blksize);
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2005-04-17 00:20:36 +02:00
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if (esp->conf.padlen)
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2005-10-11 06:11:08 +02:00
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clen = ALIGN(clen, esp->conf.padlen);
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2005-04-17 00:20:36 +02:00
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if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
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goto error;
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}
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/* Fill padding... */
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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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*(u8*)(trailer->tail + i) = i+1;
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} while (0);
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*(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
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pskb_put(skb, trailer, clen - skb->len);
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top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
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esph = (struct ipv6_esp_hdr *)skb->h.raw;
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top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
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*(u8*)(trailer->tail - 1) = *skb->nh.raw;
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*skb->nh.raw = IPPROTO_ESP;
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esph->spi = x->id.spi;
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esph->seq_no = htonl(++x->replay.oseq);
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if (esp->conf.ivlen)
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crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
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do {
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struct scatterlist *sg = &esp->sgbuf[0];
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if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
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sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
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if (!sg)
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goto error;
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}
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skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
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crypto_cipher_encrypt(tfm, sg, sg, clen);
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if (unlikely(sg != &esp->sgbuf[0]))
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kfree(sg);
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} while (0);
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if (esp->conf.ivlen) {
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memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
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crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
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}
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if (esp->auth.icv_full_len) {
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esp->auth.icv(esp, skb, (u8*)esph-skb->data,
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sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
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pskb_put(skb, trailer, alen);
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}
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err = 0;
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error:
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return err;
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}
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static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
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{
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struct ipv6hdr *iph;
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struct ipv6_esp_hdr *esph;
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struct esp_data *esp = x->data;
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struct sk_buff *trailer;
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2005-10-11 06:11:34 +02:00
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int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
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2005-04-17 00:20:36 +02:00
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int alen = esp->auth.icv_trunc_len;
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int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
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int hdr_len = skb->h.raw - skb->nh.raw;
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int nfrags;
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unsigned char *tmp_hdr = NULL;
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int ret = 0;
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if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
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ret = -EINVAL;
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goto out_nofree;
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}
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if (elen <= 0 || (elen & (blksize-1))) {
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ret = -EINVAL;
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goto out_nofree;
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}
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tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
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if (!tmp_hdr) {
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ret = -ENOMEM;
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goto out_nofree;
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}
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memcpy(tmp_hdr, skb->nh.raw, hdr_len);
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/* If integrity check is required, do this. */
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if (esp->auth.icv_full_len) {
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u8 sum[esp->auth.icv_full_len];
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u8 sum1[alen];
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esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
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if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
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BUG();
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if (unlikely(memcmp(sum, sum1, alen))) {
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x->stats.integrity_failed++;
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ret = -EINVAL;
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goto out;
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}
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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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skb->ip_summed = CHECKSUM_NONE;
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esph = (struct ipv6_esp_hdr*)skb->data;
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iph = skb->nh.ipv6h;
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/* Get ivec. This can be wrong, check against another impls. */
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if (esp->conf.ivlen)
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crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
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{
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u8 nexthdr[2];
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struct scatterlist *sg = &esp->sgbuf[0];
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u8 padlen;
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if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
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sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
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if (!sg) {
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ret = -ENOMEM;
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goto out;
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}
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}
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skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
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crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
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if (unlikely(sg != &esp->sgbuf[0]))
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kfree(sg);
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if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
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BUG();
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padlen = nexthdr[0];
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if (padlen+2 >= elen) {
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2005-08-10 05:50:53 +02:00
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LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
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2005-04-17 00:20:36 +02:00
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ret = -EINVAL;
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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->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
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skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
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memcpy(skb->nh.raw, tmp_hdr, hdr_len);
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skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
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ret = nexthdr[1];
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}
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out:
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kfree(tmp_hdr);
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out_nofree:
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return ret;
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}
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static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
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{
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struct esp_data *esp = x->data;
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2005-10-11 06:11:34 +02:00
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u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
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2005-04-17 00:20:36 +02:00
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if (x->props.mode) {
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2005-10-11 06:11:08 +02:00
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mtu = ALIGN(mtu + 2, blksize);
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2005-04-17 00:20:36 +02:00
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} else {
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/* The worst case. */
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2005-10-11 06:11:34 +02:00
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u32 padsize = ((blksize - 1) & 7) + 1;
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mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
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2005-04-17 00:20:36 +02:00
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}
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if (esp->conf.padlen)
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2005-10-11 06:11:08 +02:00
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mtu = ALIGN(mtu, esp->conf.padlen);
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2005-04-17 00:20:36 +02:00
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2005-12-09 08:11:42 +01:00
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return mtu + x->props.header_len + esp->auth.icv_trunc_len;
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2005-04-17 00:20:36 +02:00
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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, __u32 info)
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{
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struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
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struct ipv6_esp_hdr *esph = (struct ipv6_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/"
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"%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
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ntohl(esph->spi), NIP6(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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2005-09-02 02:44:29 +02:00
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crypto_free_tfm(esp->conf.tfm);
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esp->conf.tfm = NULL;
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kfree(esp->conf.ivec);
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esp->conf.ivec = NULL;
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crypto_free_tfm(esp->auth.tfm);
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esp->auth.tfm = NULL;
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kfree(esp->auth.work_icv);
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esp->auth.work_icv = NULL;
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2005-04-17 00:20:36 +02:00
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kfree(esp);
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}
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2005-06-20 22:18:08 +02:00
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static int esp6_init_state(struct xfrm_state *x)
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2005-04-17 00:20:36 +02:00
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{
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struct esp_data *esp = NULL;
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/* null auth and encryption can have zero length keys */
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if (x->aalg) {
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if (x->aalg->alg_key_len > 512)
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goto error;
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}
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if (x->ealg == NULL)
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goto error;
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if (x->encap)
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goto error;
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esp = kmalloc(sizeof(*esp), GFP_KERNEL);
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if (esp == NULL)
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return -ENOMEM;
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memset(esp, 0, sizeof(*esp));
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if (x->aalg) {
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struct xfrm_algo_desc *aalg_desc;
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esp->auth.key = x->aalg->alg_key;
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esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
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esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
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if (esp->auth.tfm == NULL)
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goto error;
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esp->auth.icv = esp_hmac_digest;
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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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if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
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crypto_tfm_alg_digestsize(esp->auth.tfm)) {
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printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
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x->aalg->alg_name,
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crypto_tfm_alg_digestsize(esp->auth.tfm),
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aalg_desc->uinfo.auth.icv_fullbits/8);
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goto error;
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}
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|
|
|
|
|
|
esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
|
|
|
|
esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
|
|
|
|
|
|
|
|
esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
|
|
|
|
if (!esp->auth.work_icv)
|
|
|
|
goto error;
|
|
|
|
}
|
|
|
|
esp->conf.key = x->ealg->alg_key;
|
|
|
|
esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
|
|
|
|
if (x->props.ealgo == SADB_EALG_NULL)
|
|
|
|
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
|
|
|
|
else
|
|
|
|
esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
|
|
|
|
if (esp->conf.tfm == NULL)
|
|
|
|
goto error;
|
|
|
|
esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
|
|
|
|
esp->conf.padlen = 0;
|
|
|
|
if (esp->conf.ivlen) {
|
|
|
|
esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
|
|
|
|
if (unlikely(esp->conf.ivec == NULL))
|
|
|
|
goto error;
|
|
|
|
get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
|
|
|
|
}
|
|
|
|
if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
|
|
|
|
goto error;
|
|
|
|
x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
|
|
|
|
if (x->props.mode)
|
|
|
|
x->props.header_len += sizeof(struct ipv6hdr);
|
|
|
|
x->data = esp;
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
error:
|
|
|
|
x->data = esp;
|
|
|
|
esp6_destroy(x);
|
|
|
|
x->data = NULL;
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct xfrm_type esp6_type =
|
|
|
|
{
|
|
|
|
.description = "ESP6",
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
.proto = IPPROTO_ESP,
|
|
|
|
.init_state = esp6_init_state,
|
|
|
|
.destructor = esp6_destroy,
|
|
|
|
.get_max_size = esp6_get_max_size,
|
|
|
|
.input = esp6_input,
|
|
|
|
.output = esp6_output
|
|
|
|
};
|
|
|
|
|
|
|
|
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");
|