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");