| /* Copyright (C) 2010-2012 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; |
| int 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_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 |
| */ |
| 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 |
| */ |
| static 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 = 1; |
| unsigned int dev_mtu; |
| |
| /* 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: |
| batadv_unicast_prepare_skb(skb, orig_node); |
| break; |
| case BATADV_UNICAST_4ADDR: |
| batadv_unicast_4addr_prepare_skb(bat_priv, skb, orig_node, |
| packet_subtype); |
| break; |
| default: |
| /* this function supports UNICAST and UNICAST_4ADDR only. It |
| * should never be invoked with any other packet type |
| */ |
| goto out; |
| } |
| |
| 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; |
| } |
| |
| batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr); |
| 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 == 1) |
| kfree_skb(skb); |
| return ret; |
| } |