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-rw-r--r--net/ipv6/esp6.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
new file mode 100644
index 000000000000..be7095d6babe
--- /dev/null
+++ b/net/ipv6/esp6.c
@@ -0,0 +1,424 @@
+/*
+ * Copyright (C)2002 USAGI/WIDE Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Authors
+ *
+ * Mitsuru KANDA @USAGI : IPv6 Support
+ * Kazunori MIYAZAWA @USAGI :
+ * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
+ *
+ * This file is derived from net/ipv4/esp.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/esp.h>
+#include <asm/scatterlist.h>
+#include <linux/crypto.h>
+#include <linux/pfkeyv2.h>
+#include <linux/random.h>
+#include <net/icmp.h>
+#include <net/ipv6.h>
+#include <linux/icmpv6.h>
+
+static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+ int hdr_len;
+ struct ipv6hdr *top_iph;
+ struct ipv6_esp_hdr *esph;
+ struct crypto_tfm *tfm;
+ struct esp_data *esp;
+ struct sk_buff *trailer;
+ int blksize;
+ int clen;
+ int alen;
+ int nfrags;
+
+ esp = x->data;
+ hdr_len = skb->h.raw - skb->data +
+ sizeof(*esph) + esp->conf.ivlen;
+
+ /* Strip IP+ESP header. */
+ __skb_pull(skb, hdr_len);
+
+ /* Now skb is pure payload to encrypt */
+ err = -ENOMEM;
+
+ /* Round to block size */
+ clen = skb->len;
+
+ alen = esp->auth.icv_trunc_len;
+ tfm = esp->conf.tfm;
+ blksize = (crypto_tfm_alg_blocksize(tfm) + 3) & ~3;
+ clen = (clen + 2 + blksize-1)&~(blksize-1);
+ if (esp->conf.padlen)
+ clen = (clen + esp->conf.padlen-1)&~(esp->conf.padlen-1);
+
+ if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
+ goto error;
+ }
+
+ /* Fill padding... */
+ do {
+ int i;
+ for (i=0; i<clen-skb->len - 2; i++)
+ *(u8*)(trailer->tail + i) = i+1;
+ } while (0);
+ *(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
+ pskb_put(skb, trailer, clen - skb->len);
+
+ top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
+ esph = (struct ipv6_esp_hdr *)skb->h.raw;
+ top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
+ *(u8*)(trailer->tail - 1) = *skb->nh.raw;
+ *skb->nh.raw = IPPROTO_ESP;
+
+ esph->spi = x->id.spi;
+ esph->seq_no = htonl(++x->replay.oseq);
+
+ if (esp->conf.ivlen)
+ crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
+
+ do {
+ struct scatterlist *sg = &esp->sgbuf[0];
+
+ if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
+ sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
+ if (!sg)
+ goto error;
+ }
+ skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
+ crypto_cipher_encrypt(tfm, sg, sg, clen);
+ if (unlikely(sg != &esp->sgbuf[0]))
+ kfree(sg);
+ } while (0);
+
+ if (esp->conf.ivlen) {
+ memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
+ crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
+ }
+
+ if (esp->auth.icv_full_len) {
+ esp->auth.icv(esp, skb, (u8*)esph-skb->data,
+ sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
+ pskb_put(skb, trailer, alen);
+ }
+
+ err = 0;
+
+error:
+ return err;
+}
+
+static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
+{
+ struct ipv6hdr *iph;
+ struct ipv6_esp_hdr *esph;
+ struct esp_data *esp = x->data;
+ struct sk_buff *trailer;
+ int blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
+ int alen = esp->auth.icv_trunc_len;
+ int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
+
+ int hdr_len = skb->h.raw - skb->nh.raw;
+ int nfrags;
+ unsigned char *tmp_hdr = NULL;
+ int ret = 0;
+
+ if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
+ ret = -EINVAL;
+ goto out_nofree;
+ }
+
+ if (elen <= 0 || (elen & (blksize-1))) {
+ ret = -EINVAL;
+ goto out_nofree;
+ }
+
+ tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
+ if (!tmp_hdr) {
+ ret = -ENOMEM;
+ goto out_nofree;
+ }
+ memcpy(tmp_hdr, skb->nh.raw, hdr_len);
+
+ /* If integrity check is required, do this. */
+ if (esp->auth.icv_full_len) {
+ u8 sum[esp->auth.icv_full_len];
+ u8 sum1[alen];
+
+ esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
+
+ if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
+ BUG();
+
+ if (unlikely(memcmp(sum, sum1, alen))) {
+ x->stats.integrity_failed++;
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ esph = (struct ipv6_esp_hdr*)skb->data;
+ iph = skb->nh.ipv6h;
+
+ /* Get ivec. This can be wrong, check against another impls. */
+ if (esp->conf.ivlen)
+ crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
+
+ {
+ u8 nexthdr[2];
+ struct scatterlist *sg = &esp->sgbuf[0];
+ u8 padlen;
+
+ if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
+ sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
+ if (!sg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
+ crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
+ if (unlikely(sg != &esp->sgbuf[0]))
+ kfree(sg);
+
+ if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
+ BUG();
+
+ padlen = nexthdr[0];
+ if (padlen+2 >= elen) {
+ LIMIT_NETDEBUG(
+ printk(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen));
+ ret = -EINVAL;
+ goto out;
+ }
+ /* ... check padding bits here. Silly. :-) */
+
+ pskb_trim(skb, skb->len - alen - padlen - 2);
+ skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
+ skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
+ memcpy(skb->nh.raw, tmp_hdr, hdr_len);
+ skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+ ret = nexthdr[1];
+ }
+
+out:
+ kfree(tmp_hdr);
+out_nofree:
+ return ret;
+}
+
+static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
+{
+ struct esp_data *esp = x->data;
+ u32 blksize = crypto_tfm_alg_blocksize(esp->conf.tfm);
+
+ if (x->props.mode) {
+ mtu = (mtu + 2 + blksize-1)&~(blksize-1);
+ } else {
+ /* The worst case. */
+ mtu += 2 + blksize;
+ }
+ if (esp->conf.padlen)
+ mtu = (mtu + esp->conf.padlen-1)&~(esp->conf.padlen-1);
+
+ return mtu + x->props.header_len + esp->auth.icv_full_len;
+}
+
+static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ int type, int code, int offset, __u32 info)
+{
+ struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
+ struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
+ struct xfrm_state *x;
+
+ if (type != ICMPV6_DEST_UNREACH &&
+ type != ICMPV6_PKT_TOOBIG)
+ return;
+
+ x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
+ if (!x)
+ return;
+ printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
+ "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
+ ntohl(esph->spi), NIP6(iph->daddr));
+ xfrm_state_put(x);
+}
+
+static void esp6_destroy(struct xfrm_state *x)
+{
+ struct esp_data *esp = x->data;
+
+ if (!esp)
+ return;
+
+ if (esp->conf.tfm) {
+ crypto_free_tfm(esp->conf.tfm);
+ esp->conf.tfm = NULL;
+ }
+ if (esp->conf.ivec) {
+ kfree(esp->conf.ivec);
+ esp->conf.ivec = NULL;
+ }
+ if (esp->auth.tfm) {
+ crypto_free_tfm(esp->auth.tfm);
+ esp->auth.tfm = NULL;
+ }
+ if (esp->auth.work_icv) {
+ kfree(esp->auth.work_icv);
+ esp->auth.work_icv = NULL;
+ }
+ kfree(esp);
+}
+
+static int esp6_init_state(struct xfrm_state *x, void *args)
+{
+ struct esp_data *esp = NULL;
+
+ /* null auth and encryption can have zero length keys */
+ if (x->aalg) {
+ if (x->aalg->alg_key_len > 512)
+ goto error;
+ }
+ if (x->ealg == NULL)
+ goto error;
+
+ if (x->encap)
+ goto error;
+
+ esp = kmalloc(sizeof(*esp), GFP_KERNEL);
+ if (esp == NULL)
+ return -ENOMEM;
+
+ memset(esp, 0, sizeof(*esp));
+
+ if (x->aalg) {
+ struct xfrm_algo_desc *aalg_desc;
+
+ esp->auth.key = x->aalg->alg_key;
+ esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
+ esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
+ if (esp->auth.tfm == NULL)
+ goto error;
+ esp->auth.icv = esp_hmac_digest;
+
+ aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
+ BUG_ON(!aalg_desc);
+
+ if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
+ crypto_tfm_alg_digestsize(esp->auth.tfm)) {
+ printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
+ x->aalg->alg_name,
+ crypto_tfm_alg_digestsize(esp->auth.tfm),
+ aalg_desc->uinfo.auth.icv_fullbits/8);
+ goto error;
+ }
+
+ 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");