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-rw-r--r--net/ipv6/esp6.c674
1 files changed, 674 insertions, 0 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
new file mode 100644
index 00000000..65dd5433
--- /dev/null
+++ b/net/ipv6/esp6.c
@@ -0,0 +1,674 @@
+/*
+ * 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 <crypto/aead.h>
+#include <crypto/authenc.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/esp.h>
+#include <linux/scatterlist.h>
+#include <linux/kernel.h>
+#include <linux/pfkeyv2.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <net/icmp.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <linux/icmpv6.h>
+
+struct esp_skb_cb {
+ struct xfrm_skb_cb xfrm;
+ void *tmp;
+};
+
+#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
+
+static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
+
+/*
+ * Allocate an AEAD request structure with extra space for SG and IV.
+ *
+ * For alignment considerations the upper 32 bits of the sequence number are
+ * placed at the front, if present. Followed by the IV, the request and finally
+ * the SG list.
+ *
+ * TODO: Use spare space in skb for this where possible.
+ */
+static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
+{
+ unsigned int len;
+
+ len = seqihlen;
+
+ len += crypto_aead_ivsize(aead);
+
+ if (len) {
+ len += crypto_aead_alignmask(aead) &
+ ~(crypto_tfm_ctx_alignment() - 1);
+ len = ALIGN(len, crypto_tfm_ctx_alignment());
+ }
+
+ len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
+ len = ALIGN(len, __alignof__(struct scatterlist));
+
+ len += sizeof(struct scatterlist) * nfrags;
+
+ return kmalloc(len, GFP_ATOMIC);
+}
+
+static inline __be32 *esp_tmp_seqhi(void *tmp)
+{
+ return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
+}
+
+static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
+{
+ return crypto_aead_ivsize(aead) ?
+ PTR_ALIGN((u8 *)tmp + seqhilen,
+ crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
+}
+
+static inline struct aead_givcrypt_request *esp_tmp_givreq(
+ struct crypto_aead *aead, u8 *iv)
+{
+ struct aead_givcrypt_request *req;
+
+ req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
+ crypto_tfm_ctx_alignment());
+ aead_givcrypt_set_tfm(req, aead);
+ return req;
+}
+
+static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
+{
+ struct aead_request *req;
+
+ req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
+ crypto_tfm_ctx_alignment());
+ aead_request_set_tfm(req, aead);
+ return req;
+}
+
+static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
+ struct aead_request *req)
+{
+ return (void *)ALIGN((unsigned long)(req + 1) +
+ crypto_aead_reqsize(aead),
+ __alignof__(struct scatterlist));
+}
+
+static inline struct scatterlist *esp_givreq_sg(
+ struct crypto_aead *aead, struct aead_givcrypt_request *req)
+{
+ return (void *)ALIGN((unsigned long)(req + 1) +
+ crypto_aead_reqsize(aead),
+ __alignof__(struct scatterlist));
+}
+
+static void esp_output_done(struct crypto_async_request *base, int err)
+{
+ struct sk_buff *skb = base->data;
+
+ kfree(ESP_SKB_CB(skb)->tmp);
+ xfrm_output_resume(skb, err);
+}
+
+static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+ struct ip_esp_hdr *esph;
+ struct crypto_aead *aead;
+ struct aead_givcrypt_request *req;
+ struct scatterlist *sg;
+ struct scatterlist *asg;
+ struct sk_buff *trailer;
+ void *tmp;
+ int blksize;
+ int clen;
+ int alen;
+ int plen;
+ int tfclen;
+ int nfrags;
+ int assoclen;
+ int sglists;
+ int seqhilen;
+ u8 *iv;
+ u8 *tail;
+ __be32 *seqhi;
+ struct esp_data *esp = x->data;
+
+ /* skb is pure payload to encrypt */
+ err = -ENOMEM;
+
+ aead = esp->aead;
+ alen = crypto_aead_authsize(aead);
+
+ tfclen = 0;
+ if (x->tfcpad) {
+ struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
+ u32 padto;
+
+ padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
+ if (skb->len < padto)
+ tfclen = padto - skb->len;
+ }
+ blksize = ALIGN(crypto_aead_blocksize(aead), 4);
+ clen = ALIGN(skb->len + 2 + tfclen, blksize);
+ if (esp->padlen)
+ clen = ALIGN(clen, esp->padlen);
+ plen = clen - skb->len - tfclen;
+
+ err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
+ if (err < 0)
+ goto error;
+ nfrags = err;
+
+ assoclen = sizeof(*esph);
+ sglists = 1;
+ seqhilen = 0;
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists += 2;
+ seqhilen += sizeof(__be32);
+ assoclen += seqhilen;
+ }
+
+ tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
+ if (!tmp)
+ goto error;
+
+ seqhi = esp_tmp_seqhi(tmp);
+ iv = esp_tmp_iv(aead, tmp, seqhilen);
+ req = esp_tmp_givreq(aead, iv);
+ asg = esp_givreq_sg(aead, req);
+ sg = asg + sglists;
+
+ /* Fill padding... */
+ tail = skb_tail_pointer(trailer);
+ if (tfclen) {
+ memset(tail, 0, tfclen);
+ tail += tfclen;
+ }
+ do {
+ int i;
+ for (i = 0; i < plen - 2; i++)
+ tail[i] = i + 1;
+ } while (0);
+ tail[plen - 2] = plen - 2;
+ tail[plen - 1] = *skb_mac_header(skb);
+ pskb_put(skb, trailer, clen - skb->len + alen);
+
+ skb_push(skb, -skb_network_offset(skb));
+ esph = ip_esp_hdr(skb);
+ *skb_mac_header(skb) = IPPROTO_ESP;
+
+ esph->spi = x->id.spi;
+ esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+
+ sg_init_table(sg, nfrags);
+ skb_to_sgvec(skb, sg,
+ esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
+ clen + alen);
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ sg_init_table(asg, 3);
+ sg_set_buf(asg, &esph->spi, sizeof(__be32));
+ *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
+ sg_set_buf(asg + 1, seqhi, seqhilen);
+ sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
+ } else
+ sg_init_one(asg, esph, sizeof(*esph));
+
+ aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
+ aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
+ aead_givcrypt_set_assoc(req, asg, assoclen);
+ aead_givcrypt_set_giv(req, esph->enc_data,
+ XFRM_SKB_CB(skb)->seq.output.low);
+
+ ESP_SKB_CB(skb)->tmp = tmp;
+ err = crypto_aead_givencrypt(req);
+ if (err == -EINPROGRESS)
+ goto error;
+
+ if (err == -EBUSY)
+ err = NET_XMIT_DROP;
+
+ kfree(tmp);
+
+error:
+ return err;
+}
+
+static int esp_input_done2(struct sk_buff *skb, int err)
+{
+ struct xfrm_state *x = xfrm_input_state(skb);
+ struct esp_data *esp = x->data;
+ struct crypto_aead *aead = esp->aead;
+ int alen = crypto_aead_authsize(aead);
+ int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
+ int elen = skb->len - hlen;
+ int hdr_len = skb_network_header_len(skb);
+ int padlen;
+ u8 nexthdr[2];
+
+ kfree(ESP_SKB_CB(skb)->tmp);
+
+ if (unlikely(err))
+ goto out;
+
+ if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
+ BUG();
+
+ err = -EINVAL;
+ padlen = nexthdr[0];
+ if (padlen + 2 + alen >= elen) {
+ LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
+ "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
+ goto out;
+ }
+
+ /* ... check padding bits here. Silly. :-) */
+
+ pskb_trim(skb, skb->len - alen - padlen - 2);
+ __skb_pull(skb, hlen);
+ skb_set_transport_header(skb, -hdr_len);
+
+ err = nexthdr[1];
+
+ /* RFC4303: Drop dummy packets without any error */
+ if (err == IPPROTO_NONE)
+ err = -EINVAL;
+
+out:
+ return err;
+}
+
+static void esp_input_done(struct crypto_async_request *base, int err)
+{
+ struct sk_buff *skb = base->data;
+
+ xfrm_input_resume(skb, esp_input_done2(skb, err));
+}
+
+static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ip_esp_hdr *esph;
+ struct esp_data *esp = x->data;
+ struct crypto_aead *aead = esp->aead;
+ struct aead_request *req;
+ struct sk_buff *trailer;
+ int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
+ int nfrags;
+ int assoclen;
+ int sglists;
+ int seqhilen;
+ int ret = 0;
+ void *tmp;
+ __be32 *seqhi;
+ u8 *iv;
+ struct scatterlist *sg;
+ struct scatterlist *asg;
+
+ if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (elen <= 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = -ENOMEM;
+
+ assoclen = sizeof(*esph);
+ sglists = 1;
+ seqhilen = 0;
+
+ if (x->props.flags & XFRM_STATE_ESN) {
+ sglists += 2;
+ seqhilen += sizeof(__be32);
+ assoclen += seqhilen;
+ }
+
+ tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
+ if (!tmp)
+ goto out;
+
+ ESP_SKB_CB(skb)->tmp = tmp;
+ seqhi = esp_tmp_seqhi(tmp);
+ iv = esp_tmp_iv(aead, tmp, seqhilen);
+ req = esp_tmp_req(aead, iv);
+ asg = esp_req_sg(aead, req);
+ sg = asg + sglists;
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ esph = (struct ip_esp_hdr *)skb->data;
+
+ /* Get ivec. This can be wrong, check against another impls. */
+ iv = esph->enc_data;
+
+ sg_init_table(sg, nfrags);
+ skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ sg_init_table(asg, 3);
+ sg_set_buf(asg, &esph->spi, sizeof(__be32));
+ *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
+ sg_set_buf(asg + 1, seqhi, seqhilen);
+ sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
+ } else
+ sg_init_one(asg, esph, sizeof(*esph));
+
+ aead_request_set_callback(req, 0, esp_input_done, skb);
+ aead_request_set_crypt(req, sg, sg, elen, iv);
+ aead_request_set_assoc(req, asg, assoclen);
+
+ ret = crypto_aead_decrypt(req);
+ if (ret == -EINPROGRESS)
+ goto out;
+
+ ret = esp_input_done2(skb, ret);
+
+out:
+ return ret;
+}
+
+static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
+{
+ struct esp_data *esp = x->data;
+ u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
+ u32 align = max_t(u32, blksize, esp->padlen);
+ unsigned int net_adj;
+
+ if (x->props.mode != XFRM_MODE_TUNNEL)
+ net_adj = sizeof(struct ipv6hdr);
+ else
+ net_adj = 0;
+
+ return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
+ net_adj) & ~(align - 1)) + (net_adj - 2);
+}
+
+static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ struct net *net = dev_net(skb->dev);
+ const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
+ struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
+ struct xfrm_state *x;
+
+ if (type != ICMPV6_DEST_UNREACH &&
+ type != ICMPV6_PKT_TOOBIG)
+ return;
+
+ x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
+ esph->spi, IPPROTO_ESP, AF_INET6);
+ if (!x)
+ return;
+ printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%pI6\n",
+ ntohl(esph->spi), &iph->daddr);
+ xfrm_state_put(x);
+}
+
+static void esp6_destroy(struct xfrm_state *x)
+{
+ struct esp_data *esp = x->data;
+
+ if (!esp)
+ return;
+
+ crypto_free_aead(esp->aead);
+ kfree(esp);
+}
+
+static int esp_init_aead(struct xfrm_state *x)
+{
+ struct esp_data *esp = x->data;
+ struct crypto_aead *aead;
+ int err;
+
+ aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
+ err = PTR_ERR(aead);
+ if (IS_ERR(aead))
+ goto error;
+
+ esp->aead = aead;
+
+ err = crypto_aead_setkey(aead, x->aead->alg_key,
+ (x->aead->alg_key_len + 7) / 8);
+ if (err)
+ goto error;
+
+ err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
+ if (err)
+ goto error;
+
+error:
+ return err;
+}
+
+static int esp_init_authenc(struct xfrm_state *x)
+{
+ struct esp_data *esp = x->data;
+ struct crypto_aead *aead;
+ struct crypto_authenc_key_param *param;
+ struct rtattr *rta;
+ char *key;
+ char *p;
+ char authenc_name[CRYPTO_MAX_ALG_NAME];
+ unsigned int keylen;
+ int err;
+
+ err = -EINVAL;
+ if (x->ealg == NULL)
+ goto error;
+
+ err = -ENAMETOOLONG;
+
+ if ((x->props.flags & XFRM_STATE_ESN)) {
+ if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
+ "authencesn(%s,%s)",
+ x->aalg ? x->aalg->alg_name : "digest_null",
+ x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
+ goto error;
+ } else {
+ if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
+ "authenc(%s,%s)",
+ x->aalg ? x->aalg->alg_name : "digest_null",
+ x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
+ goto error;
+ }
+
+ aead = crypto_alloc_aead(authenc_name, 0, 0);
+ err = PTR_ERR(aead);
+ if (IS_ERR(aead))
+ goto error;
+
+ esp->aead = aead;
+
+ keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
+ (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
+ err = -ENOMEM;
+ key = kmalloc(keylen, GFP_KERNEL);
+ if (!key)
+ goto error;
+
+ p = key;
+ rta = (void *)p;
+ rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
+ rta->rta_len = RTA_LENGTH(sizeof(*param));
+ param = RTA_DATA(rta);
+ p += RTA_SPACE(sizeof(*param));
+
+ if (x->aalg) {
+ struct xfrm_algo_desc *aalg_desc;
+
+ memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
+ p += (x->aalg->alg_key_len + 7) / 8;
+
+ aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
+ BUG_ON(!aalg_desc);
+
+ err = -EINVAL;
+ if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
+ crypto_aead_authsize(aead)) {
+ NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
+ x->aalg->alg_name,
+ crypto_aead_authsize(aead),
+ aalg_desc->uinfo.auth.icv_fullbits/8);
+ goto free_key;
+ }
+
+ err = crypto_aead_setauthsize(
+ aead, x->aalg->alg_trunc_len / 8);
+ if (err)
+ goto free_key;
+ }
+
+ param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
+ memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
+
+ err = crypto_aead_setkey(aead, key, keylen);
+
+free_key:
+ kfree(key);
+
+error:
+ return err;
+}
+
+static int esp6_init_state(struct xfrm_state *x)
+{
+ 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 const 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);
generated by cgit (git 2.34.1) at 2024-12-20 11:12:50 +0000