From a65e5481315e0754a20f58aa374423610a311f33 Mon Sep 17 00:00:00 2001 From: Linus Lüssing Date: Mon, 20 Jun 2016 21:39:54 +0200 Subject: batman-adv: Introduce forward packet creation helper MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch abstracts the forward packet creation into the new function batadv_forw_packet_alloc(). The queue counting and interface reference counters are now handled internally within batadv_forw_packet_alloc() and its batadv_forw_packet_free() counterpart. This should reduce the risk of having reference/queue counting bugs again and should increase code readibility. Signed-off-by: Linus Lüssing Signed-off-by: Marek Lindner Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/send.c | 111 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 81 insertions(+), 30 deletions(-) (limited to 'net/batman-adv/send.c') diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 6191159484df..33d8bd14140c 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -439,6 +439,13 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, BATADV_P_DATA, orig_node, vid); } +/** + * batadv_forw_packet_free - free a forwarding packet + * @forw_packet: The packet to free + * + * This frees a forwarding packet and releases any resources it might + * have claimed. + */ void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) { kfree_skb(forw_packet->skb); @@ -446,9 +453,73 @@ void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) batadv_hardif_put(forw_packet->if_incoming); if (forw_packet->if_outgoing) batadv_hardif_put(forw_packet->if_outgoing); + if (forw_packet->queue_left) + atomic_inc(forw_packet->queue_left); kfree(forw_packet); } +/** + * batadv_forw_packet_alloc - allocate a forwarding packet + * @if_incoming: The (optional) if_incoming to be grabbed + * @if_outgoing: The (optional) if_outgoing to be grabbed + * @queue_left: The (optional) queue counter to decrease + * @bat_priv: The bat_priv for the mesh of this forw_packet + * + * Allocates a forwarding packet and tries to get a reference to the + * (optional) if_incoming, if_outgoing and queue_left. If queue_left + * is NULL then bat_priv is optional, too. + * + * Return: An allocated forwarding packet on success, NULL otherwise. + */ +struct batadv_forw_packet * +batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing, + atomic_t *queue_left, + struct batadv_priv *bat_priv) +{ + struct batadv_forw_packet *forw_packet; + const char *qname; + + if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) { + qname = "unknown"; + + if (queue_left == &bat_priv->bcast_queue_left) + qname = "bcast"; + + if (queue_left == &bat_priv->batman_queue_left) + qname = "batman"; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "%s queue is full\n", qname); + + return NULL; + } + + forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); + if (!forw_packet) + goto err; + + if (if_incoming) + kref_get(&if_incoming->refcount); + + if (if_outgoing) + kref_get(&if_outgoing->refcount); + + forw_packet->skb = NULL; + forw_packet->queue_left = queue_left; + forw_packet->if_incoming = if_incoming; + forw_packet->if_outgoing = if_outgoing; + forw_packet->num_packets = 0; + + return forw_packet; + +err: + if (queue_left) + atomic_inc(queue_left); + + return NULL; +} + static void _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, struct batadv_forw_packet *forw_packet, @@ -487,24 +558,20 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, struct batadv_bcast_packet *bcast_packet; struct sk_buff *newskb; - if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) { - batadv_dbg(BATADV_DBG_BATMAN, bat_priv, - "bcast packet queue full\n"); - goto out; - } - primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) - goto out_and_inc; - - forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); + goto err; + forw_packet = batadv_forw_packet_alloc(primary_if, NULL, + &bat_priv->bcast_queue_left, + bat_priv); + batadv_hardif_put(primary_if); if (!forw_packet) - goto out_and_inc; + goto err; newskb = skb_copy(skb, GFP_ATOMIC); if (!newskb) - goto packet_free; + goto err_packet_free; /* as we have a copy now, it is safe to decrease the TTL */ bcast_packet = (struct batadv_bcast_packet *)newskb->data; @@ -513,11 +580,6 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, skb_reset_mac_header(newskb); forw_packet->skb = newskb; - forw_packet->if_incoming = primary_if; - forw_packet->if_outgoing = NULL; - - /* how often did we send the bcast packet ? */ - forw_packet->num_packets = 0; INIT_DELAYED_WORK(&forw_packet->delayed_work, batadv_send_outstanding_bcast_packet); @@ -525,13 +587,9 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay); return NETDEV_TX_OK; -packet_free: - kfree(forw_packet); -out_and_inc: - atomic_inc(&bat_priv->bcast_queue_left); -out: - if (primary_if) - batadv_hardif_put(primary_if); +err_packet_free: + batadv_forw_packet_free(forw_packet); +err: return NETDEV_TX_BUSY; } @@ -592,7 +650,6 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) out: batadv_forw_packet_free(forw_packet); - atomic_inc(&bat_priv->bcast_queue_left); } void @@ -633,9 +690,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, if (pending) { hlist_del(&forw_packet->list); - if (!forw_packet->own) - atomic_inc(&bat_priv->bcast_queue_left); - batadv_forw_packet_free(forw_packet); } } @@ -663,9 +717,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, if (pending) { hlist_del(&forw_packet->list); - if (!forw_packet->own) - atomic_inc(&bat_priv->batman_queue_left); - batadv_forw_packet_free(forw_packet); } } -- cgit v1.2.3 From f19dc7770f5d55274ef9821392199daca03469a9 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Mon, 27 Jun 2016 08:15:42 +0200 Subject: batman-adv: Remove orig_node reference handling from send_skb_unicast MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The function batadv_send_skb_unicast is not acquiring a reference for an orig_node nor removing it from any datastructure. It still reduces the reference counter for an object which is still in the hands of the caller. This is confusing and can lead in the future to problems in the reference handling of the caller function. Signed-off-by: Sven Eckelmann Acked-by: Linus Lüssing Signed-off-by: Marek Lindner Signed-off-by: Simon Wunderlich --- net/batman-adv/send.c | 25 +++++++++++++++++-------- net/batman-adv/soft-interface.c | 3 +++ 2 files changed, 20 insertions(+), 8 deletions(-) (limited to 'net/batman-adv/send.c') diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 33d8bd14140c..8d4e1f578574 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -315,8 +315,7 @@ out: * * Wrap the given skb into a batman-adv unicast or unicast-4addr header * depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied - * as packet_type. Then send this frame to the given orig_node and release a - * reference to this orig_node. + * as packet_type. Then send this frame to the given orig_node. * * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise. */ @@ -370,8 +369,6 @@ int batadv_send_skb_unicast(struct batadv_priv *bat_priv, ret = NET_XMIT_SUCCESS; out: - if (orig_node) - batadv_orig_node_put(orig_node); if (ret == NET_XMIT_DROP) kfree_skb(skb); return ret; @@ -403,6 +400,7 @@ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, struct ethhdr *ethhdr = (struct ethhdr *)skb->data; struct batadv_orig_node *orig_node; u8 *src, *dst; + int ret; src = ethhdr->h_source; dst = ethhdr->h_dest; @@ -414,8 +412,13 @@ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv, } orig_node = batadv_transtable_search(bat_priv, src, dst, vid); - return batadv_send_skb_unicast(bat_priv, skb, packet_type, - packet_subtype, orig_node, vid); + ret = batadv_send_skb_unicast(bat_priv, skb, packet_type, + packet_subtype, orig_node, vid); + + if (orig_node) + batadv_orig_node_put(orig_node); + + return ret; } /** @@ -433,10 +436,16 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid) { struct batadv_orig_node *orig_node; + int ret; orig_node = batadv_gw_get_selected_orig(bat_priv); - return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR, - BATADV_P_DATA, orig_node, vid); + ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR, + BATADV_P_DATA, orig_node, vid); + + if (orig_node) + batadv_orig_node_put(orig_node); + + return ret; } /** diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 216ac03ab432..e508bf5957b3 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -57,6 +57,7 @@ #include "hard-interface.h" #include "multicast.h" #include "network-coding.h" +#include "originator.h" #include "packet.h" #include "send.h" #include "sysfs.h" @@ -377,6 +378,8 @@ dropped: dropped_freed: batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED); end: + if (mcast_single_orig) + batadv_orig_node_put(mcast_single_orig); if (primary_if) batadv_hardif_put(primary_if); return NETDEV_TX_OK; -- cgit v1.2.3