+++ /dev/null
-/* Copyright (C) 2010-2013 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 *
-batadv_frag_merge_packet(struct list_head *head,
- struct batadv_frag_packet_list_entry *tfp,
- struct sk_buff *skb)
-{
- struct batadv_unicast_frag_packet *up;
- struct sk_buff *tmp_skb;
- struct batadv_unicast_packet *unicast_packet;
- int hdr_len = sizeof(*unicast_packet);
- int uni_diff = sizeof(*up) - hdr_len;
- uint8_t *packet_pos;
-
- up = (struct batadv_unicast_frag_packet *)skb->data;
- /* set skb to the first part and tmp_skb to the second part */
- if (up->flags & BATADV_UNI_FRAG_HEAD) {
- tmp_skb = tfp->skb;
- } else {
- tmp_skb = skb;
- skb = tfp->skb;
- }
-
- if (skb_linearize(skb) < 0 || skb_linearize(tmp_skb) < 0)
- goto err;
-
- skb_pull(tmp_skb, sizeof(*up));
- if (pskb_expand_head(skb, 0, tmp_skb->len, GFP_ATOMIC) < 0)
- goto err;
-
- /* 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);
- packet_pos = skb_pull(skb, uni_diff);
- unicast_packet = (struct batadv_unicast_packet *)packet_pos;
- unicast_packet->header.packet_type = BATADV_UNICAST;
-
- return skb;
-
-err:
- /* free buffered skb, skb will be freed later */
- kfree_skb(tfp->skb);
- return NULL;
-}
-
-static void batadv_frag_create_entry(struct list_head *head,
- struct sk_buff *skb)
-{
- struct batadv_frag_packet_list_entry *tfp;
- struct batadv_unicast_frag_packet *up;
-
- up = (struct batadv_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 batadv_frag_create_buffer(struct list_head *head)
-{
- int i;
- struct batadv_frag_packet_list_entry *tfp;
-
- for (i = 0; i < BATADV_FRAG_BUFFER_SIZE; i++) {
- tfp = kmalloc(sizeof(*tfp), GFP_ATOMIC);
- if (!tfp) {
- batadv_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 batadv_frag_packet_list_entry *
-batadv_frag_search_packet(struct list_head *head,
- const struct batadv_unicast_frag_packet *up)
-{
- struct batadv_frag_packet_list_entry *tfp;
- struct batadv_unicast_frag_packet *tmp_up = NULL;
- bool is_head_tmp, is_head;
- uint16_t search_seqno;
-
- if (up->flags & BATADV_UNI_FRAG_HEAD)
- search_seqno = ntohs(up->seqno)+1;
- else
- search_seqno = ntohs(up->seqno)-1;
-
- is_head = up->flags & BATADV_UNI_FRAG_HEAD;
-
- list_for_each_entry(tfp, head, list) {
- if (!tfp->skb)
- continue;
-
- if (tfp->seqno == ntohs(up->seqno))
- goto mov_tail;
-
- tmp_up = (struct batadv_unicast_frag_packet *)tfp->skb->data;
-
- if (tfp->seqno == search_seqno) {
- is_head_tmp = tmp_up->flags & BATADV_UNI_FRAG_HEAD;
- if (is_head_tmp != is_head)
- return tfp;
- else
- goto mov_tail;
- }
- }
- return NULL;
-
-mov_tail:
- list_move_tail(&tfp->list, head);
- return NULL;
-}
-
-void batadv_frag_list_free(struct list_head *head)
-{
- struct batadv_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 batadv_frag_reassemble_skb(struct sk_buff *skb,
- struct batadv_priv *bat_priv,
- struct sk_buff **new_skb)
-{
- struct batadv_orig_node *orig_node;
- struct batadv_frag_packet_list_entry *tmp_frag_entry;
- int ret = NET_RX_DROP;
- struct batadv_unicast_frag_packet *unicast_packet;
-
- unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
- *new_skb = NULL;
-
- orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->orig);
- if (!orig_node)
- goto out;
-
- orig_node->last_frag_packet = jiffies;
-
- if (list_empty(&orig_node->frag_list) &&
- batadv_frag_create_buffer(&orig_node->frag_list)) {
- pr_debug("couldn't create frag buffer\n");
- goto out;
- }
-
- tmp_frag_entry = batadv_frag_search_packet(&orig_node->frag_list,
- unicast_packet);
-
- if (!tmp_frag_entry) {
- batadv_frag_create_entry(&orig_node->frag_list, skb);
- ret = NET_RX_SUCCESS;
- goto out;
- }
-
- *new_skb = batadv_frag_merge_packet(&orig_node->frag_list,
- tmp_frag_entry, skb);
- /* if not, merge failed */
- if (*new_skb)
- ret = NET_RX_SUCCESS;
-
-out:
- if (orig_node)
- batadv_orig_node_free_ref(orig_node);
- return ret;
-}
-
-int batadv_frag_send_skb(struct sk_buff *skb, struct batadv_priv *bat_priv,
- struct batadv_hard_iface *hard_iface,
- const uint8_t dstaddr[])
-{
- struct batadv_unicast_packet tmp_uc, *unicast_packet;
- struct batadv_hard_iface *primary_if;
- struct sk_buff *frag_skb;
- struct batadv_unicast_frag_packet *frag1, *frag2;
- int uc_hdr_len = sizeof(*unicast_packet);
- int ucf_hdr_len = sizeof(*frag1);
- int data_len = skb->len - uc_hdr_len;
- int large_tail = 0, ret = NET_RX_DROP;
- uint16_t seqno;
-
- primary_if = batadv_primary_if_get_selected(bat_priv);
- if (!primary_if)
- goto dropped;
-
- frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
- if (!frag_skb)
- goto dropped;
-
- skb->priority = TC_PRIO_CONTROL;
- skb_reserve(frag_skb, ucf_hdr_len);
-
- unicast_packet = (struct batadv_unicast_packet *)skb->data;
- memcpy(&tmp_uc, unicast_packet, uc_hdr_len);
- skb_split(skb, frag_skb, data_len / 2 + uc_hdr_len);
-
- if (batadv_skb_head_push(skb, ucf_hdr_len - uc_hdr_len) < 0 ||
- batadv_skb_head_push(frag_skb, ucf_hdr_len) < 0)
- goto drop_frag;
-
- frag1 = (struct batadv_unicast_frag_packet *)skb->data;
- frag2 = (struct batadv_unicast_frag_packet *)frag_skb->data;
-
- memcpy(frag1, &tmp_uc, sizeof(tmp_uc));
-
- frag1->header.ttl--;
- frag1->header.version = BATADV_COMPAT_VERSION;
- frag1->header.packet_type = BATADV_UNICAST_FRAG;
-
- memcpy(frag1->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
- memcpy(frag2, frag1, sizeof(*frag2));
-
- if (data_len & 1)
- large_tail = BATADV_UNI_FRAG_LARGETAIL;
-
- frag1->flags = BATADV_UNI_FRAG_HEAD | large_tail;
- frag2->flags = large_tail;
-
- seqno = atomic_add_return(2, &hard_iface->frag_seqno);
- frag1->seqno = htons(seqno - 1);
- frag2->seqno = htons(seqno);
-
- batadv_send_skb_packet(skb, hard_iface, dstaddr);
- batadv_send_skb_packet(frag_skb, hard_iface, dstaddr);
- ret = NET_RX_SUCCESS;
- goto out;
-
-drop_frag:
- kfree_skb(frag_skb);
-dropped:
- kfree_skb(skb);
-out:
- if (primary_if)
- batadv_hardif_free_ref(primary_if);
- return ret;
-}
-
-/**
- * batadv_unicast_push_and_fill_skb - extends the buffer and initializes the
- * common fields for unicast packets
- * @skb: packet
- * @hdr_size: amount of bytes to push at the beginning of the skb
- * @orig_node: the destination node
- *
- * Returns false if the buffer extension was not possible or true otherwise
- */
-static bool batadv_unicast_push_and_fill_skb(struct sk_buff *skb, int hdr_size,
- struct batadv_orig_node *orig_node)
-{
- struct batadv_unicast_packet *unicast_packet;
- uint8_t ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
-
- if (batadv_skb_head_push(skb, hdr_size) < 0)
- return false;
-
- unicast_packet = (struct batadv_unicast_packet *)skb->data;
- unicast_packet->header.version = BATADV_COMPAT_VERSION;
- /* batman packet type: unicast */
- unicast_packet->header.packet_type = BATADV_UNICAST;
- /* set unicast ttl */
- unicast_packet->header.ttl = BATADV_TTL;
- /* copy the destination for faster routing */
- memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
- /* set the destination tt version number */
- unicast_packet->ttvn = ttvn;
-
- return true;
-}
-
-/**
- * batadv_unicast_prepare_skb - encapsulate an skb with a unicast header
- * @skb: the skb containing the payload to encapsulate
- * @orig_node: the destination node
- *
- * Returns false if the payload could not be encapsulated or true otherwise.
- *
- * This call might reallocate skb data.
- */
-static bool batadv_unicast_prepare_skb(struct sk_buff *skb,
- struct batadv_orig_node *orig_node)
-{
- size_t uni_size = sizeof(struct batadv_unicast_packet);
- return batadv_unicast_push_and_fill_skb(skb, uni_size, orig_node);
-}
-
-/**
- * batadv_unicast_4addr_prepare_skb - encapsulate an skb with a unicast4addr
- * header
- * @bat_priv: the bat priv with all the soft interface information
- * @skb: the skb containing the payload to encapsulate
- * @orig_node: the destination node
- * @packet_subtype: the batman 4addr packet subtype to use
- *
- * Returns false if the payload could not be encapsulated or true otherwise.
- *
- * This call might reallocate skb data.
- */
-bool batadv_unicast_4addr_prepare_skb(struct batadv_priv *bat_priv,
- struct sk_buff *skb,
- struct batadv_orig_node *orig,
- int packet_subtype)
-{
- struct batadv_hard_iface *primary_if;
- struct batadv_unicast_4addr_packet *unicast_4addr_packet;
- bool ret = false;
-
- primary_if = batadv_primary_if_get_selected(bat_priv);
- if (!primary_if)
- goto out;
-
- /* pull the header space and fill the unicast_packet substructure.
- * We can do that because the first member of the unicast_4addr_packet
- * is of type struct unicast_packet
- */
- if (!batadv_unicast_push_and_fill_skb(skb,
- sizeof(*unicast_4addr_packet),
- orig))
- goto out;
-
- unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
- unicast_4addr_packet->u.header.packet_type = BATADV_UNICAST_4ADDR;
- memcpy(unicast_4addr_packet->src, primary_if->net_dev->dev_addr,
- ETH_ALEN);
- unicast_4addr_packet->subtype = packet_subtype;
- unicast_4addr_packet->reserved = 0;
-
- ret = true;
-out:
- if (primary_if)
- batadv_hardif_free_ref(primary_if);
- return ret;
-}
-
-/**
- * batadv_unicast_generic_send_skb - send an skb as unicast
- * @bat_priv: the bat priv with all the soft interface information
- * @skb: payload to send
- * @packet_type: the batman unicast packet type to use
- * @packet_subtype: the batman packet subtype. It is ignored if packet_type is
- * not BATADV_UNICAT_4ADDR
- *
- * Returns 1 in case of error or 0 otherwise
- */
-int batadv_unicast_generic_send_skb(struct batadv_priv *bat_priv,
- struct sk_buff *skb, int packet_type,
- int packet_subtype)
-{
- struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
- struct batadv_unicast_packet *unicast_packet;
- struct batadv_orig_node *orig_node;
- struct batadv_neigh_node *neigh_node;
- int data_len = skb->len;
- int ret = NET_RX_DROP;
- unsigned int dev_mtu, header_len;
-
- /* get routing information */
- if (is_multicast_ether_addr(ethhdr->h_dest)) {
- orig_node = batadv_gw_get_selected_orig(bat_priv);
- if (orig_node)
- goto find_router;
- }
-
- /* check for tt host - increases orig_node refcount.
- * returns NULL in case of AP isolation
- */
- orig_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
- ethhdr->h_dest);
-
-find_router:
- /* find_router():
- * - if orig_node is NULL it returns NULL
- * - increases neigh_nodes refcount if found.
- */
- neigh_node = batadv_find_router(bat_priv, orig_node, NULL);
-
- if (!neigh_node)
- goto out;
-
- switch (packet_type) {
- case BATADV_UNICAST:
- if (!batadv_unicast_prepare_skb(skb, orig_node))
- goto out;
-
- header_len = sizeof(struct batadv_unicast_packet);
- break;
- case BATADV_UNICAST_4ADDR:
- if (!batadv_unicast_4addr_prepare_skb(bat_priv, skb, orig_node,
- packet_subtype))
- goto out;
-
- header_len = sizeof(struct batadv_unicast_4addr_packet);
- break;
- default:
- /* this function supports UNICAST and UNICAST_4ADDR only. It
- * should never be invoked with any other packet type
- */
- goto out;
- }
-
- ethhdr = (struct ethhdr *)(skb->data + header_len);
- unicast_packet = (struct batadv_unicast_packet *)skb->data;
-
- /* inform the destination node that we are still missing a correct route
- * for this client. The destination will receive this packet and will
- * try to reroute it because the ttvn contained in the header is less
- * than the current one
- */
- if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest))
- unicast_packet->ttvn = unicast_packet->ttvn - 1;
-
- dev_mtu = neigh_node->if_incoming->net_dev->mtu;
- /* fragmentation mechanism only works for UNICAST (now) */
- if (packet_type == BATADV_UNICAST &&
- atomic_read(&bat_priv->fragmentation) &&
- data_len + sizeof(*unicast_packet) > dev_mtu) {
- /* send frag skb decreases ttl */
- unicast_packet->header.ttl++;
- ret = batadv_frag_send_skb(skb, bat_priv,
- neigh_node->if_incoming,
- neigh_node->addr);
- goto out;
- }
-
- if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
- ret = 0;
-
-out:
- if (neigh_node)
- batadv_neigh_node_free_ref(neigh_node);
- if (orig_node)
- batadv_orig_node_free_ref(orig_node);
- if (ret == NET_RX_DROP)
- kfree_skb(skb);
- return ret;
-}
projects / karo-tx-linux.git / blobdiff