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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/ah4.c
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Linux-2.6.12-rc2v2.6.12-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!
Diffstat (limited to 'net/ipv4/ah4.c')
-rw-r--r--net/ipv4/ah4.c335
1 files changed, 335 insertions, 0 deletions
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
new file mode 100644
index 00000000000..0e98f2235b6
--- /dev/null
+++ b/net/ipv4/ah4.c
@@ -0,0 +1,335 @@
+#include <linux/config.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/ah.h>
+#include <linux/crypto.h>
+#include <linux/pfkeyv2.h>
+#include <net/icmp.h>
+#include <asm/scatterlist.h>
+
+
+/* Clear mutable options and find final destination to substitute
+ * into IP header for icv calculation. Options are already checked
+ * for validity, so paranoia is not required. */
+
+static int ip_clear_mutable_options(struct iphdr *iph, u32 *daddr)
+{
+ unsigned char * optptr = (unsigned char*)(iph+1);
+ int l = iph->ihl*4 - sizeof(struct iphdr);
+ int optlen;
+
+ while (l > 0) {
+ switch (*optptr) {
+ case IPOPT_END:
+ return 0;
+ case IPOPT_NOOP:
+ l--;
+ optptr++;
+ continue;
+ }
+ optlen = optptr[1];
+ if (optlen<2 || optlen>l)
+ return -EINVAL;
+ switch (*optptr) {
+ case IPOPT_SEC:
+ case 0x85: /* Some "Extended Security" crap. */
+ case 0x86: /* Another "Commercial Security" crap. */
+ case IPOPT_RA:
+ case 0x80|21: /* RFC1770 */
+ break;
+ case IPOPT_LSRR:
+ case IPOPT_SSRR:
+ if (optlen < 6)
+ return -EINVAL;
+ memcpy(daddr, optptr+optlen-4, 4);
+ /* Fall through */
+ default:
+ memset(optptr+2, 0, optlen-2);
+ }
+ l -= optlen;
+ optptr += optlen;
+ }
+ return 0;
+}
+
+static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+ struct iphdr *iph, *top_iph;
+ struct ip_auth_hdr *ah;
+ struct ah_data *ahp;
+ union {
+ struct iphdr iph;
+ char buf[60];
+ } tmp_iph;
+
+ top_iph = skb->nh.iph;
+ iph = &tmp_iph.iph;
+
+ iph->tos = top_iph->tos;
+ iph->ttl = top_iph->ttl;
+ iph->frag_off = top_iph->frag_off;
+
+ if (top_iph->ihl != 5) {
+ iph->daddr = top_iph->daddr;
+ 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;
+ }
+
+ ah = (struct ip_auth_hdr *)((char *)top_iph+top_iph->ihl*4);
+ ah->nexthdr = top_iph->protocol;
+
+ top_iph->tos = 0;
+ top_iph->tot_len = htons(skb->len);
+ top_iph->frag_off = 0;
+ top_iph->ttl = 0;
+ top_iph->protocol = IPPROTO_AH;
+ top_iph->check = 0;
+
+ ahp = x->data;
+ ah->hdrlen = (XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
+ ahp->icv_trunc_len) >> 2) - 2;
+
+ ah->reserved = 0;
+ ah->spi = x->id.spi;
+ ah->seq_no = htonl(++x->replay.oseq);
+ ahp->icv(ahp, skb, ah->auth_data);
+
+ 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));
+ }
+
+ ip_send_check(top_iph);
+
+ err = 0;
+
+error:
+ return err;
+}
+
+static int ah_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
+{
+ int ah_hlen;
+ struct iphdr *iph;
+ struct ip_auth_hdr *ah;
+ struct ah_data *ahp;
+ char work_buf[60];
+
+ if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
+ goto out;
+
+ ah = (struct ip_auth_hdr*)skb->data;
+ ahp = x->data;
+ ah_hlen = (ah->hdrlen + 2) << 2;
+
+ if (ah_hlen != XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_full_len) &&
+ ah_hlen != XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + ahp->icv_trunc_len))
+ goto out;
+
+ if (!pskb_may_pull(skb, ah_hlen))
+ goto out;
+
+ /* We are going to _remove_ AH header to keep sockets happy,
+ * so... Later this can change. */
+ if (skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ goto out;
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ ah = (struct ip_auth_hdr*)skb->data;
+ iph = skb->nh.iph;
+
+ memcpy(work_buf, iph, iph->ihl*4);
+
+ iph->ttl = 0;
+ iph->tos = 0;
+ iph->frag_off = 0;
+ iph->check = 0;
+ if (iph->ihl != 5) {
+ u32 dummy;
+ if (ip_clear_mutable_options(iph, &dummy))
+ goto out;
+ }
+ {
+ u8 auth_data[MAX_AH_AUTH_LEN];
+
+ memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
+ skb_push(skb, skb->data - skb->nh.raw);
+ ahp->icv(ahp, skb, ah->auth_data);
+ if (memcmp(ah->auth_data, auth_data, ahp->icv_trunc_len)) {
+ x->stats.integrity_failed++;
+ goto out;
+ }
+ }
+ ((struct iphdr*)work_buf)->protocol = ah->nexthdr;
+ skb->nh.raw = skb_pull(skb, ah_hlen);
+ memcpy(skb->nh.raw, work_buf, iph->ihl*4);
+ skb->nh.iph->tot_len = htons(skb->len);
+ skb_pull(skb, skb->nh.iph->ihl*4);
+ skb->h.raw = skb->data;
+
+ return 0;
+
+out:
+ return -EINVAL;
+}
+
+static void ah4_err(struct sk_buff *skb, u32 info)
+{
+ struct iphdr *iph = (struct iphdr*)skb->data;
+ struct ip_auth_hdr *ah = (struct ip_auth_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, ah->spi, IPPROTO_AH, AF_INET);
+ if (!x)
+ return;
+ printk(KERN_DEBUG "pmtu discovery on SA AH/%08x/%08x\n",
+ ntohl(ah->spi), ntohl(iph->daddr));
+ xfrm_state_put(x);
+}
+
+static int ah_init_state(struct xfrm_state *x, void *args)
+{
+ struct ah_data *ahp = NULL;
+ struct xfrm_algo_desc *aalg_desc;
+
+ if (!x->aalg)
+ goto error;
+
+ /* null auth can use a zero length key */
+ if (x->aalg->alg_key_len > 512)
+ goto error;
+
+ if (x->encap)
+ goto error;
+
+ ahp = kmalloc(sizeof(*ahp), GFP_KERNEL);
+ if (ahp == NULL)
+ return -ENOMEM;
+
+ memset(ahp, 0, sizeof(*ahp));
+
+ ahp->key = x->aalg->alg_key;
+ ahp->key_len = (x->aalg->alg_key_len+7)/8;
+ ahp->tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
+ if (!ahp->tfm)
+ goto error;
+ ahp->icv = ah_hmac_digest;
+
+ /*
+ * 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_tfm().
+ */
+ 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(ahp->tfm)) {
+ printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
+ x->aalg->alg_name, crypto_tfm_alg_digestsize(ahp->tfm),
+ aalg_desc->uinfo.auth.icv_fullbits/8);
+ goto error;
+ }
+
+ ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
+ ahp->icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
+
+ 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)
+ x->props.header_len += sizeof(struct iphdr);
+ x->data = ahp;
+
+ return 0;
+
+error:
+ if (ahp) {
+ if (ahp->work_icv)
+ kfree(ahp->work_icv);
+ if (ahp->tfm)
+ crypto_free_tfm(ahp->tfm);
+ kfree(ahp);
+ }
+ return -EINVAL;
+}
+
+static void ah_destroy(struct xfrm_state *x)
+{
+ struct ah_data *ahp = x->data;
+
+ if (!ahp)
+ return;
+
+ if (ahp->work_icv) {
+ kfree(ahp->work_icv);
+ ahp->work_icv = NULL;
+ }
+ if (ahp->tfm) {
+ crypto_free_tfm(ahp->tfm);
+ ahp->tfm = NULL;
+ }
+ kfree(ahp);
+}
+
+
+static struct xfrm_type ah_type =
+{
+ .description = "AH4",
+ .owner = THIS_MODULE,
+ .proto = IPPROTO_AH,
+ .init_state = ah_init_state,
+ .destructor = ah_destroy,
+ .input = ah_input,
+ .output = ah_output
+};
+
+static struct net_protocol ah4_protocol = {
+ .handler = xfrm4_rcv,
+ .err_handler = ah4_err,
+ .no_policy = 1,
+};
+
+static int __init ah4_init(void)
+{
+ if (xfrm_register_type(&ah_type, AF_INET) < 0) {
+ printk(KERN_INFO "ip ah init: can't add xfrm type\n");
+ return -EAGAIN;
+ }
+ if (inet_add_protocol(&ah4_protocol, IPPROTO_AH) < 0) {
+ printk(KERN_INFO "ip ah init: can't add protocol\n");
+ xfrm_unregister_type(&ah_type, AF_INET);
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static void __exit ah4_fini(void)
+{
+ if (inet_del_protocol(&ah4_protocol, IPPROTO_AH) < 0)
+ printk(KERN_INFO "ip ah close: can't remove protocol\n");
+ if (xfrm_unregister_type(&ah_type, AF_INET) < 0)
+ printk(KERN_INFO "ip ah close: can't remove xfrm type\n");
+}
+
+module_init(ah4_init);
+module_exit(ah4_fini);
+MODULE_LICENSE("GPL");