ah4: convert to ahash
[linux-2.6.git] / net / ipv4 / ah4.c
index 5c662703eb1e9cf917df97b41e024c52b946be38..d07b0c1dd3507a41ce95f3b7232bb5d5654c5fd4 100644 (file)
@@ -1,3 +1,4 @@
+#include <crypto/hash.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <net/ip.h>
@@ -5,10 +6,67 @@
 #include <net/ah.h>
 #include <linux/crypto.h>
 #include <linux/pfkeyv2.h>
-#include <linux/spinlock.h>
+#include <linux/scatterlist.h>
 #include <net/icmp.h>
 #include <net/protocol.h>
 
+struct ah_skb_cb {
+       struct xfrm_skb_cb xfrm;
+       void *tmp;
+};
+
+#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
+
+static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
+                         unsigned int size)
+{
+       unsigned int len;
+
+       len = size + crypto_ahash_digestsize(ahash) +
+             (crypto_ahash_alignmask(ahash) &
+              ~(crypto_tfm_ctx_alignment() - 1));
+
+       len = ALIGN(len, crypto_tfm_ctx_alignment());
+
+       len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
+       len = ALIGN(len, __alignof__(struct scatterlist));
+
+       len += sizeof(struct scatterlist) * nfrags;
+
+       return kmalloc(len, GFP_ATOMIC);
+}
+
+static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
+{
+       return tmp + offset;
+}
+
+static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
+                            unsigned int offset)
+{
+       return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
+}
+
+static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
+                                              u8 *icv)
+{
+       struct ahash_request *req;
+
+       req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
+                               crypto_tfm_ctx_alignment());
+
+       ahash_request_set_tfm(req, ahash);
+
+       return req;
+}
+
+static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
+                                            struct ahash_request *req)
+{
+       return (void *)ALIGN((unsigned long)(req + 1) +
+                            crypto_ahash_reqsize(ahash),
+                            __alignof__(struct scatterlist));
+}
 
 /* Clear mutable options and find final destination to substitute
  * into IP header for icv calculation. Options are already checked
@@ -54,20 +112,72 @@ static int ip_clear_mutable_options(struct iphdr *iph, __be32 *daddr)
        return 0;
 }
 
+static void ah_output_done(struct crypto_async_request *base, int err)
+{
+       u8 *icv;
+       struct iphdr *iph;
+       struct sk_buff *skb = base->data;
+       struct xfrm_state *x = skb_dst(skb)->xfrm;
+       struct ah_data *ahp = x->data;
+       struct iphdr *top_iph = ip_hdr(skb);
+       struct ip_auth_hdr *ah = ip_auth_hdr(skb);
+       int ihl = ip_hdrlen(skb);
+
+       iph = AH_SKB_CB(skb)->tmp;
+       icv = ah_tmp_icv(ahp->ahash, iph, ihl);
+       memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
+
+       top_iph->tos = iph->tos;
+       top_iph->ttl = iph->ttl;
+       top_iph->frag_off = iph->frag_off;
+       if (top_iph->ihl != 5) {
+               top_iph->daddr = iph->daddr;
+               memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
+       }
+
+       err = ah->nexthdr;
+
+       kfree(AH_SKB_CB(skb)->tmp);
+       xfrm_output_resume(skb, err);
+}
+
 static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
 {
        int err;
+       int nfrags;
+       int ihl;
+       u8 *icv;
+       struct sk_buff *trailer;
+       struct crypto_ahash *ahash;
+       struct ahash_request *req;
+       struct scatterlist *sg;
        struct iphdr *iph, *top_iph;
        struct ip_auth_hdr *ah;
        struct ah_data *ahp;
-       union {
-               struct iphdr    iph;
-               char            buf[60];
-       } tmp_iph;
+
+       ahp = x->data;
+       ahash = ahp->ahash;
+
+       if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
+               goto out;
+       nfrags = err;
 
        skb_push(skb, -skb_network_offset(skb));
+       ah = ip_auth_hdr(skb);
+       ihl = ip_hdrlen(skb);
+
+       err = -ENOMEM;
+       iph = ah_alloc_tmp(ahash, nfrags, ihl);
+       if (!iph)
+               goto out;
+
+       icv = ah_tmp_icv(ahash, iph, ihl);
+       req = ah_tmp_req(ahash, icv);
+       sg = ah_req_sg(ahash, req);
+
+       memset(ah->auth_data, 0, ahp->icv_trunc_len);
+
        top_iph = ip_hdr(skb);
-       iph = &tmp_iph.iph;
 
        iph->tos = top_iph->tos;
        iph->ttl = top_iph->ttl;
@@ -78,10 +188,9 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
                memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
                err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
                if (err)
-                       goto error;
+                       goto out_free;
        }
 
-       ah = ip_auth_hdr(skb);
        ah->nexthdr = *skb_mac_header(skb);
        *skb_mac_header(skb) = IPPROTO_AH;
 
@@ -91,20 +200,31 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
        top_iph->ttl = 0;
        top_iph->check = 0;
 
-       ahp = x->data;
        ah->hdrlen  = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
 
        ah->reserved = 0;
        ah->spi = x->id.spi;
        ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
 
-       spin_lock_bh(&x->lock);
-       err = ah_mac_digest(ahp, skb, ah->auth_data);
-       memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
-       spin_unlock_bh(&x->lock);
+       sg_init_table(sg, nfrags);
+       skb_to_sgvec(skb, sg, 0, skb->len);
 
-       if (err)
-               goto error;
+       ahash_request_set_crypt(req, sg, icv, skb->len);
+       ahash_request_set_callback(req, 0, ah_output_done, skb);
+
+       AH_SKB_CB(skb)->tmp = iph;
+
+       err = crypto_ahash_digest(req);
+       if (err) {
+               if (err == -EINPROGRESS)
+                       goto out;
+
+               if (err == -EBUSY)
+                       err = NET_XMIT_DROP;
+               goto out_free;
+       }
+
+       memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
 
        top_iph->tos = iph->tos;
        top_iph->ttl = iph->ttl;
@@ -114,28 +234,67 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
                memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
        }
 
-       err = 0;
-
-error:
+out_free:
+       kfree(iph);
+out:
        return err;
 }
 
+static void ah_input_done(struct crypto_async_request *base, int err)
+{
+       u8 *auth_data;
+       u8 *icv;
+       struct iphdr *work_iph;
+       struct sk_buff *skb = base->data;
+       struct xfrm_state *x = xfrm_input_state(skb);
+       struct ah_data *ahp = x->data;
+       struct ip_auth_hdr *ah = ip_auth_hdr(skb);
+       int ihl = ip_hdrlen(skb);
+       int ah_hlen = (ah->hdrlen + 2) << 2;
+
+       work_iph = AH_SKB_CB(skb)->tmp;
+       auth_data = ah_tmp_auth(work_iph, ihl);
+       icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
+
+       err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
+       if (err)
+               goto out;
+
+       skb->network_header += ah_hlen;
+       memcpy(skb_network_header(skb), work_iph, ihl);
+       __skb_pull(skb, ah_hlen + ihl);
+       skb_set_transport_header(skb, -ihl);
+
+       err = ah->nexthdr;
+out:
+       kfree(AH_SKB_CB(skb)->tmp);
+       xfrm_input_resume(skb, err);
+}
+
 static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 {
        int ah_hlen;
        int ihl;
        int nexthdr;
-       int err = -EINVAL;
-       struct iphdr *iph;
+       int nfrags;
+       u8 *auth_data;
+       u8 *icv;
+       struct sk_buff *trailer;
+       struct crypto_ahash *ahash;
+       struct ahash_request *req;
+       struct scatterlist *sg;
+       struct iphdr *iph, *work_iph;
        struct ip_auth_hdr *ah;
        struct ah_data *ahp;
-       char work_buf[60];
+       int err = -ENOMEM;
 
        if (!pskb_may_pull(skb, sizeof(*ah)))
                goto out;
 
        ah = (struct ip_auth_hdr *)skb->data;
        ahp = x->data;
+       ahash = ahp->ahash;
+
        nexthdr = ah->nexthdr;
        ah_hlen = (ah->hdrlen + 2) << 2;
 
@@ -156,9 +315,24 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
 
        ah = (struct ip_auth_hdr *)skb->data;
        iph = ip_hdr(skb);
+       ihl = ip_hdrlen(skb);
+
+       if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
+               goto out;
+       nfrags = err;
+
+       work_iph = ah_alloc_tmp(ahash, nfrags, ihl + ahp->icv_trunc_len);
+       if (!work_iph)
+               goto out;
+
+       auth_data = ah_tmp_auth(work_iph, ihl);
+       icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
+       req = ah_tmp_req(ahash, icv);
+       sg = ah_req_sg(ahash, req);
 
-       ihl = skb->data - skb_network_header(skb);
-       memcpy(work_buf, iph, ihl);
+       memcpy(work_iph, iph, ihl);
+       memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
+       memset(ah->auth_data, 0, ahp->icv_trunc_len);
 
        iph->ttl = 0;
        iph->tos = 0;
@@ -166,35 +340,44 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
        iph->check = 0;
        if (ihl > sizeof(*iph)) {
                __be32 dummy;
-               if (ip_clear_mutable_options(iph, &dummy))
-                       goto out;
+               err = ip_clear_mutable_options(iph, &dummy);
+               if (err)
+                       goto out_free;
        }
 
-       spin_lock(&x->lock);
-       {
-               u8 auth_data[MAX_AH_AUTH_LEN];
+       skb_push(skb, ihl);
 
-               memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
-               skb_push(skb, ihl);
-               err = ah_mac_digest(ahp, skb, ah->auth_data);
-               if (err)
-                       goto unlock;
-               if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len))
-                       err = -EBADMSG;
+       sg_init_table(sg, nfrags);
+       skb_to_sgvec(skb, sg, 0, skb->len);
+
+       ahash_request_set_crypt(req, sg, icv, skb->len);
+       ahash_request_set_callback(req, 0, ah_input_done, skb);
+
+       AH_SKB_CB(skb)->tmp = work_iph;
+
+       err = crypto_ahash_digest(req);
+       if (err) {
+               if (err == -EINPROGRESS)
+                       goto out;
+
+               if (err == -EBUSY)
+                       err = NET_XMIT_DROP;
+               goto out_free;
        }
-unlock:
-       spin_unlock(&x->lock);
 
+       err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
        if (err)
-               goto out;
+               goto out_free;
 
        skb->network_header += ah_hlen;
-       memcpy(skb_network_header(skb), work_buf, ihl);
-       skb->transport_header = skb->network_header;
+       memcpy(skb_network_header(skb), work_iph, ihl);
        __skb_pull(skb, ah_hlen + ihl);
+       skb_set_transport_header(skb, -ihl);
 
-       return nexthdr;
+       err = nexthdr;
 
+out_free:
+       kfree (work_iph);
 out:
        return err;
 }
@@ -222,7 +405,7 @@ static int ah_init_state(struct xfrm_state *x)
 {
        struct ah_data *ahp = NULL;
        struct xfrm_algo_desc *aalg_desc;
-       struct crypto_hash *tfm;
+       struct crypto_ahash *ahash;
 
        if (!x->aalg)
                goto error;
@@ -231,31 +414,31 @@ static int ah_init_state(struct xfrm_state *x)
                goto error;
 
        ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
-       if (ahp == NULL)
+       if (!ahp)
                return -ENOMEM;
 
-       tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
-       if (IS_ERR(tfm))
+       ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
+       if (IS_ERR(ahash))
                goto error;
 
-       ahp->tfm = tfm;
-       if (crypto_hash_setkey(tfm, x->aalg->alg_key,
-                              (x->aalg->alg_key_len + 7) / 8))
+       ahp->ahash = ahash;
+       if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
+                               (x->aalg->alg_key_len + 7) / 8))
                goto error;
 
        /*
         * Lookup the algorithm description maintained by xfrm_algo,
         * verify crypto transform properties, and store information
         * we need for AH processing.  This lookup cannot fail here
-        * after a successful crypto_alloc_hash().
+        * after a successful crypto_alloc_ahash().
         */
        aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
        BUG_ON(!aalg_desc);
 
        if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
-           crypto_hash_digestsize(tfm)) {
+           crypto_ahash_digestsize(ahash)) {
                printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
-                      x->aalg->alg_name, crypto_hash_digestsize(tfm),
+                      x->aalg->alg_name, crypto_ahash_digestsize(ahash),
                       aalg_desc->uinfo.auth.icv_fullbits/8);
                goto error;
        }
@@ -265,10 +448,6 @@ static int ah_init_state(struct xfrm_state *x)
 
        BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
 
-       ahp->work_icv = kmalloc(ahp->icv_full_len, GFP_KERNEL);
-       if (!ahp->work_icv)
-               goto error;
-
        x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
                                          ahp->icv_trunc_len);
        if (x->props.mode == XFRM_MODE_TUNNEL)
@@ -279,8 +458,7 @@ static int ah_init_state(struct xfrm_state *x)
 
 error:
        if (ahp) {
-               kfree(ahp->work_icv);
-               crypto_free_hash(ahp->tfm);
+               crypto_free_ahash(ahp->ahash);
                kfree(ahp);
        }
        return -EINVAL;
@@ -293,8 +471,7 @@ static void ah_destroy(struct xfrm_state *x)
        if (!ahp)
                return;
 
-       kfree(ahp->work_icv);
-       crypto_free_hash(ahp->tfm);
+       crypto_free_ahash(ahp->ahash);
        kfree(ahp);
 }