diff options
| -rw-r--r-- | net/batman-adv/fragmentation.c | 121 | ||||
| -rw-r--r-- | net/batman-adv/fragmentation.h | 3 | ||||
| -rw-r--r-- | net/batman-adv/send.c | 21 | ||||
| -rw-r--r-- | net/batman-adv/soft-interface.c | 7 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 6 |
5 files changed, 154 insertions, 4 deletions
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index c829d3cee89c..271d321b3a04 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -368,3 +368,124 @@ out: batadv_neigh_node_free_ref(neigh_node); return ret; } + +/** + * batadv_frag_create - create a fragment from skb + * @skb: skb to create fragment from + * @frag_head: header to use in new fragment + * @mtu: size of new fragment + * + * Split the passed skb into two fragments: A new one with size matching the + * passed mtu and the old one with the rest. The new skb contains data from the + * tail of the old skb. + * + * Returns the new fragment, NULL on error. + */ +static struct sk_buff *batadv_frag_create(struct sk_buff *skb, + struct batadv_frag_packet *frag_head, + unsigned int mtu) +{ + struct sk_buff *skb_fragment; + unsigned header_size = sizeof(*frag_head); + unsigned fragment_size = mtu - header_size; + + skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN); + if (!skb_fragment) + goto err; + + skb->priority = TC_PRIO_CONTROL; + + /* Eat the last mtu-bytes of the skb */ + skb_reserve(skb_fragment, header_size + ETH_HLEN); + skb_split(skb, skb_fragment, skb->len - fragment_size); + + /* Add the header */ + skb_push(skb_fragment, header_size); + memcpy(skb_fragment->data, frag_head, header_size); + +err: + return skb_fragment; +} + +/** + * batadv_frag_send_packet - create up to 16 fragments from the passed skb + * @skb: skb to create fragments from + * @orig_node: final destination of the created fragments + * @neigh_node: next-hop of the created fragments + * + * Returns true on success, false otherwise. + */ +bool batadv_frag_send_packet(struct sk_buff *skb, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node) +{ + struct batadv_priv *bat_priv; + struct batadv_hard_iface *primary_if; + struct batadv_frag_packet frag_header; + struct sk_buff *skb_fragment; + unsigned mtu = neigh_node->if_incoming->net_dev->mtu; + unsigned header_size = sizeof(frag_header); + unsigned max_fragment_size, max_packet_size; + + /* To avoid merge and refragmentation at next-hops we never send + * fragments larger than BATADV_FRAG_MAX_FRAG_SIZE + */ + mtu = min_t(unsigned, mtu, BATADV_FRAG_MAX_FRAG_SIZE); + max_fragment_size = (mtu - header_size - ETH_HLEN); + max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS; + + /* Don't even try to fragment, if we need more than 16 fragments */ + if (skb->len > max_packet_size) + goto out_err; + + bat_priv = orig_node->bat_priv; + primary_if = batadv_primary_if_get_selected(bat_priv); + if (!primary_if) + goto out_err; + + /* Create one header to be copied to all fragments */ + frag_header.header.packet_type = BATADV_UNICAST_FRAG; + frag_header.header.version = BATADV_COMPAT_VERSION; + frag_header.header.ttl = BATADV_TTL; + frag_header.seqno = htons(atomic_inc_return(&bat_priv->frag_seqno)); + frag_header.reserved = 0; + frag_header.no = 0; + frag_header.total_size = htons(skb->len); + memcpy(frag_header.orig, primary_if->net_dev->dev_addr, ETH_ALEN); + memcpy(frag_header.dest, orig_node->orig, ETH_ALEN); + + /* Eat and send fragments from the tail of skb */ + while (skb->len > max_fragment_size) { + skb_fragment = batadv_frag_create(skb, &frag_header, mtu); + if (!skb_fragment) + goto out_err; + + batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); + batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, + skb_fragment->len + ETH_HLEN); + batadv_send_skb_packet(skb_fragment, neigh_node->if_incoming, + neigh_node->addr); + frag_header.no++; + + /* The initial check in this function should cover this case */ + if (frag_header.no == BATADV_FRAG_MAX_FRAGMENTS - 1) + goto out_err; + } + + /* Make room for the fragment header. */ + if (batadv_skb_head_push(skb, header_size) < 0 || + pskb_expand_head(skb, header_size + ETH_HLEN, 0, GFP_ATOMIC) < 0) + goto out_err; + + memcpy(skb->data, &frag_header, header_size); + + /* Send the last fragment */ + batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_TX); + batadv_add_counter(bat_priv, BATADV_CNT_FRAG_TX_BYTES, + skb->len + ETH_HLEN); + batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr); + + return true; +out_err: + return false; +} diff --git a/net/batman-adv/fragmentation.h b/net/batman-adv/fragmentation.h index 883a6f46005e..ca029e2676e7 100644 --- a/net/batman-adv/fragmentation.h +++ b/net/batman-adv/fragmentation.h @@ -27,6 +27,9 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, struct batadv_orig_node *orig_node_src); bool batadv_frag_skb_buffer(struct sk_buff **skb, struct batadv_orig_node *orig_node); +bool batadv_frag_send_packet(struct sk_buff *skb, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node); /** * batadv_frag_check_entry - check if a list of fragments has timed out diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index b8356ec067bf..1a1aa59d78ee 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -28,8 +28,7 @@ #include "gateway_client.h" #include "originator.h" #include "network-coding.h" - -#include <linux/if_ether.h> +#include "fragmentation.h" static void batadv_send_outstanding_bcast_packet(struct work_struct *work); @@ -109,7 +108,19 @@ int batadv_send_skb_to_orig(struct sk_buff *skb, /* batadv_find_router() increases neigh_nodes refcount if found. */ neigh_node = batadv_find_router(bat_priv, orig_node, recv_if); if (!neigh_node) - return ret; + goto out; + + /* Check if the skb is too large to send in one piece and fragment + * it if needed. + */ + if (atomic_read(&bat_priv->fragmentation) && + skb->len > neigh_node->if_incoming->net_dev->mtu) { + /* Fragment and send packet. */ + if (batadv_frag_send_packet(skb, orig_node, neigh_node)) + ret = NET_XMIT_SUCCESS; + + goto out; + } /* try to network code the packet, if it is received on an interface * (i.e. being forwarded). If the packet originates from this node or if @@ -123,7 +134,9 @@ int batadv_send_skb_to_orig(struct sk_buff *skb, ret = NET_XMIT_SUCCESS; } - batadv_neigh_node_free_ref(neigh_node); +out: + if (neigh_node) + batadv_neigh_node_free_ref(neigh_node); return ret; } diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index dd189e6bf05a..18b1fd915d1f 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -442,6 +442,7 @@ static void batadv_softif_destroy_finish(struct work_struct *work) static int batadv_softif_init_late(struct net_device *dev) { struct batadv_priv *bat_priv; + uint32_t random_seqno; int ret; size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM; @@ -491,6 +492,10 @@ static int batadv_softif_init_late(struct net_device *dev) bat_priv->tt.last_changeset = NULL; bat_priv->tt.last_changeset_len = 0; + /* randomize initial seqno to avoid collision */ + get_random_bytes(&random_seqno, sizeof(random_seqno)); + atomic_set(&bat_priv->frag_seqno, random_seqno); + bat_priv->primary_if = NULL; bat_priv->num_ifaces = 0; @@ -758,6 +763,8 @@ static const struct { { "mgmt_tx_bytes" }, { "mgmt_rx" }, { "mgmt_rx_bytes" }, + { "frag_tx" }, + { "frag_tx_bytes" }, { "frag_rx" }, { "frag_rx_bytes" }, { "frag_fwd" }, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 5a2cc7a9a620..d517d5dde6ad 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -300,6 +300,8 @@ struct batadv_bcast_duplist_entry { * @BATADV_CNT_MGMT_TX_BYTES: transmitted routing protocol traffic bytes counter * @BATADV_CNT_MGMT_RX: received routing protocol traffic packet counter * @BATADV_CNT_MGMT_RX_BYTES: received routing protocol traffic bytes counter + * @BATADV_CNT_FRAG_TX: transmitted fragment traffic packet counter + * @BATADV_CNT_FRAG_TX_BYTES: transmitted fragment traffic bytes counter * @BATADV_CNT_FRAG_RX: received fragment traffic packet counter * @BATADV_CNT_FRAG_RX_BYTES: received fragment traffic bytes counter * @BATADV_CNT_FRAG_FWD: forwarded fragment traffic packet counter @@ -341,6 +343,8 @@ enum batadv_counters { BATADV_CNT_MGMT_TX_BYTES, BATADV_CNT_MGMT_RX, BATADV_CNT_MGMT_RX_BYTES, + BATADV_CNT_FRAG_TX, + BATADV_CNT_FRAG_TX_BYTES, BATADV_CNT_FRAG_RX, BATADV_CNT_FRAG_RX_BYTES, BATADV_CNT_FRAG_FWD, @@ -542,6 +546,7 @@ struct batadv_priv_nc { * @aggregated_ogms: bool indicating whether OGM aggregation is enabled * @bonding: bool indicating whether traffic bonding is enabled * @fragmentation: bool indicating whether traffic fragmentation is enabled + * @frag_seqno: incremental counter to identify chains of egress fragments * @ap_isolation: bool indicating whether ap isolation is enabled * @bridge_loop_avoidance: bool indicating whether bridge loop avoidance is * enabled @@ -585,6 +590,7 @@ struct batadv_priv { atomic_t aggregated_ogms; atomic_t bonding; atomic_t fragmentation; + atomic_t frag_seqno; atomic_t ap_isolation; #ifdef CONFIG_BATMAN_ADV_BLA atomic_t bridge_loop_avoidance; |