1 files changed, 343 insertions, 0 deletions

diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
new file mode 100644
index 000000000000..dc2e28bed844
--- /dev/null
+++ b/net/batman-adv/unicast.c
@@ -0,0 +1,343 @@
+/*
+ * Copyright (C) 2010 B.A.T.M.A.N. contributors:
+ *
+ * Andreas Langer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#include "main.h"
+#include "unicast.h"
+#include "send.h"
+#include "soft-interface.h"
+#include "gateway_client.h"
+#include "originator.h"
+#include "hash.h"
+#include "translation-table.h"
+#include "routing.h"
+#include "hard-interface.h"
+
+
+static struct sk_buff *frag_merge_packet(struct list_head *head,
+                                         struct frag_packet_list_entry *tfp,
+                                         struct sk_buff *skb)
+{
+        struct unicast_frag_packet *up =
+                (struct unicast_frag_packet *)skb->data;
+        struct sk_buff *tmp_skb;
+        struct unicast_packet *unicast_packet;
+        int hdr_len = sizeof(struct unicast_packet),
+            uni_diff = sizeof(struct unicast_frag_packet) - hdr_len;
+
+        /* set skb to the first part and tmp_skb to the second part */
+        if (up->flags & UNI_FRAG_HEAD) {
+                tmp_skb = tfp->skb;
+        } else {
+                tmp_skb = skb;
+                skb = tfp->skb;
+        }
+
+        skb_pull(tmp_skb, sizeof(struct unicast_frag_packet));
+        if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0) {
+                /* free buffered skb, skb will be freed later */
+                kfree_skb(tfp->skb);
+                return NULL;
+        }
+
+        /* move free entry to end */
+        tfp->skb = NULL;
+        tfp->seqno = 0;
+        list_move_tail(&tfp->list, head);
+
+        memcpy(skb_put(skb, tmp_skb->len), tmp_skb->data, tmp_skb->len);
+        kfree_skb(tmp_skb);
+
+        memmove(skb->data + uni_diff, skb->data, hdr_len);
+        unicast_packet = (struct unicast_packet *) skb_pull(skb, uni_diff);
+        unicast_packet->packet_type = BAT_UNICAST;
+
+        return skb;
+}
+
+static void frag_create_entry(struct list_head *head, struct sk_buff *skb)
+{
+        struct frag_packet_list_entry *tfp;
+        struct unicast_frag_packet *up =
+                (struct unicast_frag_packet *)skb->data;
+
+        /* free and oldest packets stand at the end */
+        tfp = list_entry((head)->prev, typeof(*tfp), list);
+        kfree_skb(tfp->skb);
+
+        tfp->seqno = ntohs(up->seqno);
+        tfp->skb = skb;
+        list_move(&tfp->list, head);
+        return;
+}
+
+static int frag_create_buffer(struct list_head *head)
+{
+        int i;
+        struct frag_packet_list_entry *tfp;
+
+        for (i = 0; i < FRAG_BUFFER_SIZE; i++) {
+                tfp = kmalloc(sizeof(struct frag_packet_list_entry),
+                        GFP_ATOMIC);
+                if (!tfp) {
+                        frag_list_free(head);
+                        return -ENOMEM;
+                }
+                tfp->skb = NULL;
+                tfp->seqno = 0;
+                INIT_LIST_HEAD(&tfp->list);
+                list_add(&tfp->list, head);
+        }
+
+        return 0;
+}
+
+static struct frag_packet_list_entry *frag_search_packet(struct list_head *head,
+                                                 struct unicast_frag_packet *up)
+{
+        struct frag_packet_list_entry *tfp;
+        struct unicast_frag_packet *tmp_up = NULL;
+        uint16_t search_seqno;
+
+        if (up->flags & UNI_FRAG_HEAD)
+                search_seqno = ntohs(up->seqno)+1;
+        else
+                search_seqno = ntohs(up->seqno)-1;
+
+        list_for_each_entry(tfp, head, list) {
+
+                if (!tfp->skb)
+                        continue;
+
+                if (tfp->seqno == ntohs(up->seqno))
+                        goto mov_tail;
+
+                tmp_up = (struct unicast_frag_packet *)tfp->skb->data;
+
+                if (tfp->seqno == search_seqno) {
+
+                        if ((tmp_up->flags & UNI_FRAG_HEAD) !=
+                            (up->flags & UNI_FRAG_HEAD))
+                                return tfp;
+                        else
+                                goto mov_tail;
+                }
+        }
+        return NULL;
+
+mov_tail:
+        list_move_tail(&tfp->list, head);
+        return NULL;
+}
+
+void frag_list_free(struct list_head *head)
+{
+        struct frag_packet_list_entry *pf, *tmp_pf;
+
+        if (!list_empty(head)) {
+
+                list_for_each_entry_safe(pf, tmp_pf, head, list) {
+                        kfree_skb(pf->skb);
+                        list_del(&pf->list);
+                        kfree(pf);
+                }
+        }
+        return;
+}
+
+/* frag_reassemble_skb():
+ * returns NET_RX_DROP if the operation failed - skb is left intact
+ * returns NET_RX_SUCCESS if the fragment was buffered (skb_new will be NULL)
+ * or the skb could be reassembled (skb_new will point to the new packet and
+ * skb was freed)
+ */
+int frag_reassemble_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
+                        struct sk_buff **new_skb)
+{
+        struct orig_node *orig_node;
+        struct frag_packet_list_entry *tmp_frag_entry;
+        int ret = NET_RX_DROP;
+        struct unicast_frag_packet *unicast_packet =
+                (struct unicast_frag_packet *)skb->data;
+
+        *new_skb = NULL;
+        spin_lock_bh(&bat_priv->orig_hash_lock);
+        orig_node = ((struct orig_node *)
+                    hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
+                              unicast_packet->orig));
+
+        if (!orig_node) {
+                pr_debug("couldn't find originator in orig_hash\n");
+                goto out;
+        }
+
+        orig_node->last_frag_packet = jiffies;
+
+        if (list_empty(&orig_node->frag_list) &&
+            frag_create_buffer(&orig_node->frag_list)) {
+                pr_debug("couldn't create frag buffer\n");
+                goto out;
+        }
+
+        tmp_frag_entry = frag_search_packet(&orig_node->frag_list,
+                                            unicast_packet);
+
+        if (!tmp_frag_entry) {
+                frag_create_entry(&orig_node->frag_list, skb);
+                ret = NET_RX_SUCCESS;
+                goto out;
+        }
+
+        *new_skb = frag_merge_packet(&orig_node->frag_list, tmp_frag_entry,
+                                     skb);
+        /* if not, merge failed */
+        if (*new_skb)
+                ret = NET_RX_SUCCESS;
+out:
+        spin_unlock_bh(&bat_priv->orig_hash_lock);
+
+        return ret;
+}
+
+int frag_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv,
+                  struct batman_if *batman_if, uint8_t dstaddr[])
+{
+        struct unicast_packet tmp_uc, *unicast_packet;
+        struct sk_buff *frag_skb;
+        struct unicast_frag_packet *frag1, *frag2;
+        int uc_hdr_len = sizeof(struct unicast_packet);
+        int ucf_hdr_len = sizeof(struct unicast_frag_packet);
+        int data_len = skb->len;
+
+        if (!bat_priv->primary_if)
+                goto dropped;
+
+        unicast_packet = (struct unicast_packet *) skb->data;
+
+        memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
+        frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
+        skb_split(skb, frag_skb, data_len / 2);
+
+        if (my_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
+            my_skb_head_push(frag_skb, ucf_hdr_len) < 0)
+                goto drop_frag;
+
+        frag1 = (struct unicast_frag_packet *)skb->data;
+        frag2 = (struct unicast_frag_packet *)frag_skb->data;
+
+        memcpy(frag1, &tmp_uc, sizeof(struct unicast_packet));
+
+        frag1->ttl--;
+        frag1->version = COMPAT_VERSION;
+        frag1->packet_type = BAT_UNICAST_FRAG;
+
+        memcpy(frag1->orig, bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
+        memcpy(frag2, frag1, sizeof(struct unicast_frag_packet));
+
+        frag1->flags |= UNI_FRAG_HEAD;
+        frag2->flags &= ~UNI_FRAG_HEAD;
+
+        frag1->seqno = htons((uint16_t)atomic_inc_return(
+                             &batman_if->frag_seqno));
+        frag2->seqno = htons((uint16_t)atomic_inc_return(
+                             &batman_if->frag_seqno));
+
+        send_skb_packet(skb, batman_if, dstaddr);
+        send_skb_packet(frag_skb, batman_if, dstaddr);
+        return NET_RX_SUCCESS;
+
+drop_frag:
+        kfree_skb(frag_skb);
+dropped:
+        kfree_skb(skb);
+        return NET_RX_DROP;
+}
+
+int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
+{
+        struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
+        struct unicast_packet *unicast_packet;
+        struct orig_node *orig_node;
+        struct batman_if *batman_if;
+        struct neigh_node *router;
+        int data_len = skb->len;
+        uint8_t dstaddr[6];
+
+        spin_lock_bh(&bat_priv->orig_hash_lock);
+
+        /* get routing information */
+        if (is_multicast_ether_addr(ethhdr->h_dest))
+                orig_node = (struct orig_node *)gw_get_selected(bat_priv);
+        else
+                orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
+                                                           compare_orig,
+                                                           choose_orig,
+                                                           ethhdr->h_dest));
+
+        /* check for hna host */
+        if (!orig_node)
+                orig_node = transtable_search(bat_priv, ethhdr->h_dest);
+
+        router = find_router(bat_priv, orig_node, NULL);
+
+        if (!router)
+                goto unlock;
+
+        /* don't lock while sending the packets ... we therefore
+                * copy the required data before sending */
+
+        batman_if = router->if_incoming;
+        memcpy(dstaddr, router->addr, ETH_ALEN);
+
+        spin_unlock_bh(&bat_priv->orig_hash_lock);
+
+        if (batman_if->if_status != IF_ACTIVE)
+                goto dropped;
+
+        if (my_skb_head_push(skb, sizeof(struct unicast_packet)) < 0)
+                goto dropped;
+
+        unicast_packet = (struct unicast_packet *)skb->data;
+
+        unicast_packet->version = COMPAT_VERSION;
+        /* batman packet type: unicast */
+        unicast_packet->packet_type = BAT_UNICAST;
+        /* set unicast ttl */
+        unicast_packet->ttl = TTL;
+        /* copy the destination for faster routing */
+        memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
+
+        if (atomic_read(&bat_priv->fragmentation) &&
+            data_len + sizeof(struct unicast_packet) >
+            batman_if->net_dev->mtu) {
+                /* send frag skb decreases ttl */
+                unicast_packet->ttl++;
+                return frag_send_skb(skb, bat_priv, batman_if,
+                                     dstaddr);
+        }
+        send_skb_packet(skb, batman_if, dstaddr);
+        return 0;
+
+unlock:
+        spin_unlock_bh(&bat_priv->orig_hash_lock);
+dropped:
+        kfree_skb(skb);
+        return 1;
+}