Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 510 insertions, 0 deletions

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
new file mode 100644
index 000000000000..053a883247ba
--- /dev/null
+++ b/net/ipv4/esp4.c
@@ -0,0 +1,510 @@
+#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/udp.h>
+
+/* decapsulation data for use when post-processing */
+struct esp_decap_data {
+	xfrm_address_t	saddr;
+	__u16		sport;
+	__u8		proto;
+};
+
+static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int err;
+	struct iphdr *top_iph;
+	struct ip_esp_hdr *esph;
+	struct crypto_tfm *tfm;
+	struct esp_data *esp;
+	struct sk_buff *trailer;
+	int blksize;
+	int clen;
+	int alen;
+	int nfrags;
+
+	/* Strip IP+ESP header. */
+	__skb_pull(skb, skb->h.raw - skb->data);
+	/* Now skb is pure payload to encrypt */
+
+	err = -ENOMEM;
+
+	/* Round to block size */
+	clen = skb->len;
+
+	esp = x->data;
+	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);
+
+	__skb_push(skb, skb->data - skb->nh.raw);
+	top_iph = skb->nh.iph;
+	esph = (struct ip_esp_hdr *)(skb->nh.raw + top_iph->ihl*4);
+	top_iph->tot_len = htons(skb->len + alen);
+	*(u8*)(trailer->tail - 1) = top_iph->protocol;
+
+	/* this is non-NULL only with UDP Encapsulation */
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap = x->encap;
+		struct udphdr *uh;
+		u32 *udpdata32;
+
+		uh = (struct udphdr *)esph;
+		uh->source = encap->encap_sport;
+		uh->dest = encap->encap_dport;
+		uh->len = htons(skb->len + alen - top_iph->ihl*4);
+		uh->check = 0;
+
+		switch (encap->encap_type) {
+		default:
+		case UDP_ENCAP_ESPINUDP:
+			esph = (struct ip_esp_hdr *)(uh + 1);
+			break;
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			udpdata32 = (u32 *)(uh + 1);
+			udpdata32[0] = udpdata32[1] = 0;
+			esph = (struct ip_esp_hdr *)(udpdata32 + 2);
+			break;
+		}
+
+		top_iph->protocol = IPPROTO_UDP;
+	} else
+		top_iph->protocol = 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 ip_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
+		pskb_put(skb, trailer, alen);
+	}
+
+	ip_send_check(top_iph);
+
+	err = 0;
+
+error:
+	return err;
+}
+
+/*
+ * Note: detecting truncated vs. non-truncated authentication data is very
+ * expensive, so we only support truncated data, which is the recommended
+ * and common case.
+ */
+static int esp_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	struct ip_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 ip_esp_hdr) - esp->conf.ivlen - alen;
+	int nfrags;
+	int encap_len = 0;
+
+	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr)))
+		goto out;
+
+	if (elen <= 0 || (elen & (blksize-1)))
+		goto out;
+
+	/* 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++;
+			goto out;
+		}
+	}
+
+	if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0)
+		goto out;
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	esph = (struct ip_esp_hdr*)skb->data;
+	iph = skb->nh.iph;
+
+	/* 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 workbuf[60];
+		int padlen;
+
+		if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
+			sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
+			if (!sg)
+				goto out;
+		}
+		skb_to_sgvec(skb, sg, sizeof(struct ip_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)
+			goto out;
+
+		/* ... check padding bits here. Silly. :-) */ 
+
+		if (x->encap && decap && decap->decap_type) {
+			struct esp_decap_data *encap_data;
+			struct udphdr *uh = (struct udphdr *) (iph+1);
+
+			encap_data = (struct esp_decap_data *) (decap->decap_data);
+			encap_data->proto = 0;
+
+			switch (decap->decap_type) {
+			case UDP_ENCAP_ESPINUDP:
+			case UDP_ENCAP_ESPINUDP_NON_IKE:
+				encap_data->proto = AF_INET;
+				encap_data->saddr.a4 = iph->saddr;
+				encap_data->sport = uh->source;
+				encap_len = (void*)esph - (void*)uh;
+				break;
+
+			default:
+				goto out;
+			}
+		}
+
+		iph->protocol = nexthdr[1];
+		pskb_trim(skb, skb->len - alen - padlen - 2);
+		memcpy(workbuf, skb->nh.raw, iph->ihl*4);
+		skb->h.raw = skb_pull(skb, sizeof(struct ip_esp_hdr) + esp->conf.ivlen);
+		skb->nh.raw += encap_len + sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
+		memcpy(skb->nh.raw, workbuf, iph->ihl*4);
+		skb->nh.iph->tot_len = htons(skb->len);
+	}
+
+	return 0;
+
+out:
+	return -EINVAL;
+}
+
+static int esp_post_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
+{
+  
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap;
+		struct esp_decap_data *decap_data;
+
+		encap = x->encap;
+		decap_data = (struct esp_decap_data *)(decap->decap_data);
+
+		/* first, make sure that the decap type == the encap type */
+		if (encap->encap_type != decap->decap_type)
+			return -EINVAL;
+
+		switch (encap->encap_type) {
+		default:
+		case UDP_ENCAP_ESPINUDP:
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			/*
+			 * 1) if the NAT-T peer's IP or port changed then
+			 *    advertize the change to the keying daemon.
+			 *    This is an inbound SA, so just compare
+			 *    SRC ports.
+			 */
+			if (decap_data->proto == AF_INET &&
+			    (decap_data->saddr.a4 != x->props.saddr.a4 ||
+			     decap_data->sport != encap->encap_sport)) {
+				xfrm_address_t ipaddr;
+
+				ipaddr.a4 = decap_data->saddr.a4;
+				km_new_mapping(x, &ipaddr, decap_data->sport);
+					
+				/* XXX: perhaps add an extra
+				 * policy check here, to see
+				 * if we should allow or
+				 * reject a packet from a
+				 * different source
+				 * address/port.
+				 */
+			}
+		
+			/*
+			 * 2) ignore UDP/TCP checksums in case
+			 *    of NAT-T in Transport Mode, or
+			 *    perform other post-processing fixes
+			 *    as per * draft-ietf-ipsec-udp-encaps-06,
+			 *    section 3.1.2
+			 */
+			if (!x->props.mode)
+				skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+			break;
+		}
+	}
+	return 0;
+}
+
+static u32 esp4_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_trunc_len;
+}
+
+static void esp4_err(struct sk_buff *skb, u32 info)
+{
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct ip_esp_hdr *esph = (struct ip_esp_hdr*)(skb->data+(iph->ihl<<2));
+	struct xfrm_state *x;
+
+	if (skb->h.icmph->type != ICMP_DEST_UNREACH ||
+	    skb->h.icmph->code != ICMP_FRAG_NEEDED)
+		return;
+
+	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET);
+	if (!x)
+		return;
+	NETDEBUG(printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
+			ntohl(esph->spi), ntohl(iph->daddr)));
+	xfrm_state_put(x);
+}
+
+static void esp_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 esp_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;
+
+	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)) {
+			NETDEBUG(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 ip_esp_hdr) + esp->conf.ivlen;
+	if (x->props.mode)
+		x->props.header_len += sizeof(struct iphdr);
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap = x->encap;
+
+		switch (encap->encap_type) {
+		default:
+			goto error;
+		case UDP_ENCAP_ESPINUDP:
+			x->props.header_len += sizeof(struct udphdr);
+			break;
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
+			break;
+		}
+	}
+	x->data = esp;
+	x->props.trailer_len = esp4_get_max_size(x, 0) - x->props.header_len;
+	return 0;
+
+error:
+	x->data = esp;
+	esp_destroy(x);
+	x->data = NULL;
+	return -EINVAL;
+}
+
+static struct xfrm_type esp_type =
+{
+	.description	= "ESP4",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_ESP,
+	.init_state	= esp_init_state,
+	.destructor	= esp_destroy,
+	.get_max_size	= esp4_get_max_size,
+	.input		= esp_input,
+	.post_input	= esp_post_input,
+	.output		= esp_output
+};
+
+static struct net_protocol esp4_protocol = {
+	.handler	=	xfrm4_rcv,
+	.err_handler	=	esp4_err,
+	.no_policy	=	1,
+};
+
+static int __init esp4_init(void)
+{
+	struct xfrm_decap_state decap;
+
+	if (sizeof(struct esp_decap_data)  <
+	    sizeof(decap.decap_data)) {
+		extern void decap_data_too_small(void);
+
+		decap_data_too_small();
+	}
+
+	if (xfrm_register_type(&esp_type, AF_INET) < 0) {
+		printk(KERN_INFO "ip esp init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+	if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
+		printk(KERN_INFO "ip esp init: can't add protocol\n");
+		xfrm_unregister_type(&esp_type, AF_INET);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static void __exit esp4_fini(void)
+{
+	if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
+		printk(KERN_INFO "ip esp close: can't remove protocol\n");
+	if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
+		printk(KERN_INFO "ip esp close: can't remove xfrm type\n");
+}
+
+module_init(esp4_init);
+module_exit(esp4_fini);
+MODULE_LICENSE("GPL");