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");