diff options
author | Kim Kibum <kb0929.kim@samsung.com> | 2012-04-29 16:59:19 +0900 |
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committer | Kim Kibum <kb0929.kim@samsung.com> | 2012-04-29 16:59:19 +0900 |
commit | c1775d1a93a77a57380a4ce87ac3a8f807c944b2 (patch) | |
tree | e1f233f2af38ee247a677082198dd3a69a12a5a1 /net/ipv6/esp6.c | |
parent | 2c2dcd5ffef2e97176e6a55e45512177e55e6fb9 (diff) | |
download | linux-2.6.36-master.tar.gz linux-2.6.36-master.tar.bz2 linux-2.6.36-master.zip |
Diffstat (limited to 'net/ipv6/esp6.c')
-rw-r--r-- | net/ipv6/esp6.c | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c new file mode 100644 index 00000000..ee9b93bd --- /dev/null +++ b/net/ipv6/esp6.c @@ -0,0 +1,594 @@ +/* + * 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])) + +/* + * Allocate an AEAD request structure with extra space for SG and IV. + * + * For alignment considerations the IV is placed at the front, followed + * by 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) +{ + unsigned int len; + + 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 u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp) +{ + return crypto_aead_ivsize(aead) ? + PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp; +} + +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 nfrags; + u8 *iv; + u8 *tail; + struct esp_data *esp = x->data; + + /* skb is pure payload to encrypt */ + err = -ENOMEM; + + /* Round to block size */ + clen = skb->len; + + aead = esp->aead; + alen = crypto_aead_authsize(aead); + + blksize = ALIGN(crypto_aead_blocksize(aead), 4); + clen = ALIGN(clen + 2, blksize); + if (esp->padlen) + clen = ALIGN(clen, esp->padlen); + + if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0) + goto error; + nfrags = err; + + tmp = esp_alloc_tmp(aead, nfrags + 1); + if (!tmp) + goto error; + + iv = esp_tmp_iv(aead, tmp); + req = esp_tmp_givreq(aead, iv); + asg = esp_givreq_sg(aead, req); + sg = asg + 1; + + /* Fill padding... */ + tail = skb_tail_pointer(trailer); + do { + int i; + for (i=0; i<clen-skb->len - 2; i++) + tail[i] = i + 1; + } while (0); + tail[clen-skb->len - 2] = (clen - skb->len) - 2; + tail[clen - skb->len - 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); + + sg_init_table(sg, nfrags); + skb_to_sgvec(skb, sg, + esph->enc_data + crypto_aead_ivsize(aead) - skb->data, + clen + alen); + 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, sizeof(*esph)); + aead_givcrypt_set_giv(req, esph->enc_data, + XFRM_SKB_CB(skb)->seq.output); + + 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 ret = 0; + void *tmp; + 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; + tmp = esp_alloc_tmp(aead, nfrags + 1); + if (!tmp) + goto out; + + ESP_SKB_CB(skb)->tmp = tmp; + iv = esp_tmp_iv(aead, tmp); + req = esp_tmp_req(aead, iv); + asg = esp_req_sg(aead, req); + sg = asg + 1; + + 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); + 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, sizeof(*esph)); + + 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); + u32 rem; + + mtu -= x->props.header_len + crypto_aead_authsize(esp->aead); + rem = mtu & (align - 1); + mtu &= ~(align - 1); + + if (x->props.mode != XFRM_MODE_TUNNEL) { + u32 padsize = ((blksize - 1) & 7) + 1; + mtu -= blksize - padsize; + mtu += min_t(u32, blksize - padsize, rem); + } + + return mtu - 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); + struct ipv6hdr *iph = (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, (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 (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); |