[B.A.T.M.A.N.] [PATCH 09/17] batman-adv: use consume_skb for non-dropped packets

From: Sven Eckelmann sven@narfation.org

kfree_skb assumes that an skb is dropped after an failure and notes that. consume_skb should be used in non-failure situations. Such information is important for dropmonitor netlink which tells how many packets were dropped and where this drop happened.

Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/bat_iv_ogm.c | 13 ++++++++----- net/batman-adv/fragmentation.c | 20 ++++++++++++++------ net/batman-adv/network-coding.c | 24 +++++++++++++++--------- net/batman-adv/send.c | 27 +++++++++++++++++++-------- net/batman-adv/send.h | 3 ++- net/batman-adv/soft-interface.c | 2 +- 6 files changed, 59 insertions(+), 30 deletions(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 0b9be62..310f391 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -698,7 +698,7 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,

forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size); if (!forw_packet_aggr->skb) { - batadv_forw_packet_free(forw_packet_aggr); + batadv_forw_packet_free(forw_packet_aggr, true); return; }

@@ -1611,7 +1611,7 @@ batadv_iv_ogm_process_per_outif(const struct sk_buff *skb, int ogm_offset, if (hardif_neigh) batadv_hardif_neigh_put(hardif_neigh);

- kfree_skb(skb_priv); + consume_skb(skb_priv); }

/** @@ -1783,6 +1783,7 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) struct delayed_work *delayed_work; struct batadv_forw_packet *forw_packet; struct batadv_priv *bat_priv; + bool dropped = false;

delayed_work = to_delayed_work(work); forw_packet = container_of(delayed_work, struct batadv_forw_packet, @@ -1792,8 +1793,10 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) hlist_del(&forw_packet->list); spin_unlock_bh(&bat_priv->forw_bat_list_lock);

- if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) { + dropped = true; goto out; + }

batadv_iv_ogm_emit(forw_packet);

@@ -1810,7 +1813,7 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) batadv_iv_ogm_schedule(forw_packet->if_incoming);

out: - batadv_forw_packet_free(forw_packet); + batadv_forw_packet_free(forw_packet, dropped); }

static int batadv_iv_ogm_receive(struct sk_buff *skb, @@ -1851,7 +1854,7 @@ static int batadv_iv_ogm_receive(struct sk_buff *skb, ogm_packet = (struct batadv_ogm_packet *)packet_pos; }

- kfree_skb(skb); + consume_skb(skb); return NET_RX_SUCCESS; }

diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 2b967a3..a2e28a1 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -42,17 +42,23 @@ /** * batadv_frag_clear_chain - delete entries in the fragment buffer chain * @head: head of chain with entries. + * @dropped: whether the chain is cleared because all fragments are dropped * * Free fragments in the passed hlist. Should be called with appropriate lock. */ -static void batadv_frag_clear_chain(struct hlist_head *head) +static void batadv_frag_clear_chain(struct hlist_head *head, bool dropped) { struct batadv_frag_list_entry *entry; struct hlist_node *node;

hlist_for_each_entry_safe(entry, node, head, list) { hlist_del(&entry->list); - kfree_skb(entry->skb); + + if (dropped) + kfree_skb(entry->skb); + else + consume_skb(entry->skb); + kfree(entry); } } @@ -73,7 +79,7 @@ void batadv_frag_purge_orig(struct batadv_orig_node *orig_node, spin_lock_bh(&chain->lock);

if (!check_cb || check_cb(chain)) { - batadv_frag_clear_chain(&chain->fragment_list); + batadv_frag_clear_chain(&chain->fragment_list, true); chain->size = 0; }

@@ -118,7 +124,7 @@ static bool batadv_frag_init_chain(struct batadv_frag_table_entry *chain, return false;

if (!hlist_empty(&chain->fragment_list)) - batadv_frag_clear_chain(&chain->fragment_list); + batadv_frag_clear_chain(&chain->fragment_list, true);

chain->size = 0; chain->seqno = seqno; @@ -220,7 +226,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node, * exceeds the maximum size of one merged packet. Don't allow * packets to have different total_size. */ - batadv_frag_clear_chain(&chain->fragment_list); + batadv_frag_clear_chain(&chain->fragment_list, true); chain->size = 0; } else if (ntohs(frag_packet->total_size) == chain->size) { /* All fragments received. Hand over chain to caller. */ @@ -254,6 +260,7 @@ batadv_frag_merge_packets(struct hlist_head *chain) struct batadv_frag_list_entry *entry; struct sk_buff *skb_out; int size, hdr_size = sizeof(struct batadv_frag_packet); + bool dropped = false;

/* Remove first entry, as this is the destination for the rest of the * fragments. @@ -270,6 +277,7 @@ batadv_frag_merge_packets(struct hlist_head *chain) if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) { kfree_skb(skb_out); skb_out = NULL; + dropped = true; goto free; }

@@ -291,7 +299,7 @@ batadv_frag_merge_packets(struct hlist_head *chain)

free: /* Locking is not needed, because 'chain' is not part of any orig. */ - batadv_frag_clear_chain(chain); + batadv_frag_clear_chain(chain, dropped); return skb_out; }

diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index c213dde..3af66d3 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -260,10 +260,16 @@ static void batadv_nc_path_put(struct batadv_nc_path *nc_path) /** * batadv_nc_packet_free - frees nc packet * @nc_packet: the nc packet to free + * @dropped: whether the packet is freed because is is dropped */ -static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet) +static void batadv_nc_packet_free(struct batadv_nc_packet *nc_packet, + bool dropped) { - kfree_skb(nc_packet->skb); + if (dropped) + kfree_skb(nc_packet->skb); + else + consume_skb(nc_packet->skb); + batadv_nc_path_put(nc_packet->nc_path); kfree(nc_packet); } @@ -576,7 +582,7 @@ static void batadv_nc_send_packet(struct batadv_nc_packet *nc_packet) { batadv_send_unicast_skb(nc_packet->skb, nc_packet->neigh_node); nc_packet->skb = NULL; - batadv_nc_packet_free(nc_packet); + batadv_nc_packet_free(nc_packet, false); }

/** @@ -610,7 +616,7 @@ static bool batadv_nc_sniffed_purge(struct batadv_priv *bat_priv,

/* purge nc packet */ list_del(&nc_packet->list); - batadv_nc_packet_free(nc_packet); + batadv_nc_packet_free(nc_packet, true);

res = true;

@@ -1208,11 +1214,11 @@ static bool batadv_nc_code_packets(struct batadv_priv *bat_priv, }

/* skb_src is now coded into skb_dest, so free it */ - kfree_skb(skb_src); + consume_skb(skb_src);

/* avoid duplicate free of skb from nc_packet */ nc_packet->skb = NULL; - batadv_nc_packet_free(nc_packet); + batadv_nc_packet_free(nc_packet, false);

/* Send the coded packet and return true */ batadv_send_unicast_skb(skb_dest, first_dest); @@ -1399,7 +1405,7 @@ static void batadv_nc_skb_store_before_coding(struct batadv_priv *bat_priv, /* batadv_nc_skb_store_for_decoding() clones the skb, so we must free * our ref */ - kfree_skb(skb); + consume_skb(skb); }

/** @@ -1723,7 +1729,7 @@ batadv_nc_skb_decode_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, ether_addr_copy(unicast_packet->dest, orig_dest); unicast_packet->ttvn = ttvn;

- batadv_nc_packet_free(nc_packet); + batadv_nc_packet_free(nc_packet, false); return unicast_packet; }

@@ -1860,7 +1866,7 @@ static int batadv_nc_recv_coded_packet(struct sk_buff *skb, return batadv_recv_unicast_packet(skb, recv_if);

free_nc_packet: - batadv_nc_packet_free(nc_packet); + batadv_nc_packet_free(nc_packet, true); return NET_RX_DROP; }

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index d9bbb00..0f86293 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -451,13 +451,19 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, /** * batadv_forw_packet_free - free a forwarding packet * @forw_packet: The packet to free + * @dropped: whether the packet is freed because is is dropped * * This frees a forwarding packet and releases any resources it might * have claimed. */ -void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) +void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet, + bool dropped) { - kfree_skb(forw_packet->skb); + if (dropped) + kfree_skb(forw_packet->skb); + else + consume_skb(forw_packet->skb); + if (forw_packet->if_incoming) batadv_hardif_put(forw_packet->if_incoming); if (forw_packet->if_outgoing) @@ -598,7 +604,7 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, return NETDEV_TX_OK;

err_packet_free: - batadv_forw_packet_free(forw_packet); + batadv_forw_packet_free(forw_packet, true); err: return NETDEV_TX_BUSY; } @@ -613,6 +619,7 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) struct sk_buff *skb1; struct net_device *soft_iface; struct batadv_priv *bat_priv; + bool dropped = false; u8 *neigh_addr; u8 *orig_neigh; int ret = 0; @@ -627,11 +634,15 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) hlist_del(&forw_packet->list); spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

- if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) { + dropped = true; goto out; + }

- if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) + if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) { + dropped = true; goto out; + }

bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;

@@ -709,7 +720,7 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) }

out: - batadv_forw_packet_free(forw_packet); + batadv_forw_packet_free(forw_packet, dropped); }

void @@ -750,7 +761,7 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,

if (pending) { hlist_del(&forw_packet->list); - batadv_forw_packet_free(forw_packet); + batadv_forw_packet_free(forw_packet, true); } } spin_unlock_bh(&bat_priv->forw_bcast_list_lock); @@ -777,7 +788,7 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,

if (pending) { hlist_del(&forw_packet->list); - batadv_forw_packet_free(forw_packet); + batadv_forw_packet_free(forw_packet, true); } } spin_unlock_bh(&bat_priv->forw_bat_list_lock); diff --git a/net/batman-adv/send.h b/net/batman-adv/send.h index 86009b5..c580194 100644 --- a/net/batman-adv/send.h +++ b/net/batman-adv/send.h @@ -27,7 +27,8 @@

struct sk_buff;

-void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet); +void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet, + bool dropped); struct batadv_forw_packet * batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, struct batadv_hard_iface *if_outgoing, diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 109f53b..2f0304e 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -362,7 +362,7 @@ static int batadv_interface_tx(struct sk_buff *skb, /* a copy is stored in the bcast list, therefore removing * the original skb. */ - kfree_skb(skb); + consume_skb(skb);

/* unicast packet */ } else {