[B.A.T.M.A.N.] [PATCH 13/17] batman-adv: Consume skb in receive handlers

From: Sven Eckelmann sven@narfation.org

Receiving functions in Linux consume the supplied skbuff. Doing the same in the batadv_rx_handler functions makes the behavior more similar to the rest of the Linux network code.

Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/bat_iv_ogm.c | 22 ++++-- net/batman-adv/bat_v_elp.c | 30 ++++---- net/batman-adv/bat_v_ogm.c | 15 ++-- net/batman-adv/main.c | 11 +-- net/batman-adv/network-coding.c | 11 +-- net/batman-adv/routing.c | 149 +++++++++++++++++++++++++++------------- 6 files changed, 153 insertions(+), 85 deletions(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 310f391..bd39247 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -1823,17 +1823,18 @@ static int batadv_iv_ogm_receive(struct sk_buff *skb, struct batadv_ogm_packet *ogm_packet; u8 *packet_pos; int ogm_offset; - bool ret; + bool res; + int ret = NET_RX_DROP;

- ret = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN); - if (!ret) - return NET_RX_DROP; + res = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN); + if (!res) + goto free_skb;

/* did we receive a B.A.T.M.A.N. IV OGM packet on an interface * that does not have B.A.T.M.A.N. IV enabled ? */ if (bat_priv->algo_ops->iface.enable != batadv_iv_ogm_iface_enable) - return NET_RX_DROP; + goto free_skb;

batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, @@ -1854,8 +1855,15 @@ static int batadv_iv_ogm_receive(struct sk_buff *skb, ogm_packet = (struct batadv_ogm_packet *)packet_pos; }

- consume_skb(skb); - return NET_RX_SUCCESS; + ret = NET_RX_SUCCESS; + +free_skb: + if (ret == NET_RX_SUCCESS) + consume_skb(skb); + else + kfree_skb(skb); + + return ret; }

#ifdef CONFIG_BATMAN_ADV_DEBUGFS diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index ee08540..54bdd41 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -492,20 +492,21 @@ int batadv_v_elp_packet_recv(struct sk_buff *skb, struct batadv_elp_packet *elp_packet; struct batadv_hard_iface *primary_if; struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb); - bool ret; + bool res; + int ret = NET_RX_DROP;

- ret = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); - if (!ret) - return NET_RX_DROP; + res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); + if (!res) + goto free_skb;

if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) - return NET_RX_DROP; + goto free_skb;

/* did we receive a B.A.T.M.A.N. V ELP packet on an interface * that does not have B.A.T.M.A.N. V ELP enabled ? */ if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) - return NET_RX_DROP; + goto free_skb;

elp_packet = (struct batadv_elp_packet *)skb->data;

@@ -516,14 +517,19 @@ int batadv_v_elp_packet_recv(struct sk_buff *skb,

primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) - goto out; + goto free_skb;

batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming, elp_packet);

-out: - if (primary_if) - batadv_hardif_put(primary_if); - consume_skb(skb); - return NET_RX_SUCCESS; + ret = NET_RX_SUCCESS; + batadv_hardif_put(primary_if); + +free_skb: + if (ret == NET_RX_SUCCESS) + consume_skb(skb); + else + kfree_skb(skb); + + return ret; } diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 9922ccd..38b9aab 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -810,18 +810,18 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, * B.A.T.M.A.N. V enabled ? */ if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) - return NET_RX_DROP; + goto free_skb;

if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) - return NET_RX_DROP; + goto free_skb;

if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) - return NET_RX_DROP; + goto free_skb;

ogm_packet = (struct batadv_ogm2_packet *)skb->data;

if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) - return NET_RX_DROP; + goto free_skb;

batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, @@ -842,7 +842,12 @@ int batadv_v_ogm_packet_recv(struct sk_buff *skb, }

ret = NET_RX_SUCCESS; - consume_skb(skb); + +free_skb: + if (ret == NET_RX_SUCCESS) + consume_skb(skb); + else + kfree_skb(skb);

return ret; } diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 5e4e818..6b5dae6 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -402,6 +402,8 @@ void batadv_skb_set_priority(struct sk_buff *skb, int offset) static int batadv_recv_unhandled_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { + kfree_skb(skb); + return NET_RX_DROP; }

@@ -416,7 +418,6 @@ int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev, struct batadv_ogm_packet *batadv_ogm_packet; struct batadv_hard_iface *hard_iface; u8 idx; - int ret;

hard_iface = container_of(ptype, struct batadv_hard_iface, batman_adv_ptype); @@ -466,14 +467,8 @@ int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev, /* reset control block to avoid left overs from previous users */ memset(skb->cb, 0, sizeof(struct batadv_skb_cb));

- /* all receive handlers return whether they received or reused - * the supplied skb. if not, we have to free the skb. - */ idx = batadv_ogm_packet->packet_type; - ret = (*batadv_rx_handler[idx])(skb, hard_iface); - - if (ret == NET_RX_DROP) - kfree_skb(skb); + (*batadv_rx_handler[idx])(skb, hard_iface);

batadv_hardif_put(hard_iface);

diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 3af66d3..ab5a3bf 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -1819,11 +1819,11 @@ static int batadv_nc_recv_coded_packet(struct sk_buff *skb,

/* Check if network coding is enabled */ if (!atomic_read(&bat_priv->network_coding)) - return NET_RX_DROP; + goto free_skb;

/* Make sure we can access (and remove) header */ if (unlikely(!pskb_may_pull(skb, hdr_size))) - return NET_RX_DROP; + goto free_skb;

coded_packet = (struct batadv_coded_packet *)skb->data; ethhdr = eth_hdr(skb); @@ -1831,7 +1831,7 @@ static int batadv_nc_recv_coded_packet(struct sk_buff *skb, /* Verify frame is destined for us */ if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest) && !batadv_is_my_mac(bat_priv, coded_packet->second_dest)) - return NET_RX_DROP; + goto free_skb;

/* Update stat counter */ if (batadv_is_my_mac(bat_priv, coded_packet->second_dest)) @@ -1841,7 +1841,7 @@ static int batadv_nc_recv_coded_packet(struct sk_buff *skb, coded_packet); if (!nc_packet) { batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); - return NET_RX_DROP; + goto free_skb; }

/* Make skb's linear, because decoding accesses the entire buffer */ @@ -1867,6 +1867,9 @@ static int batadv_nc_recv_coded_packet(struct sk_buff *skb,

free_nc_packet: batadv_nc_packet_free(nc_packet, true); +free_skb: + kfree_skb(skb); + return NET_RX_DROP; }

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 4d2679a..105d4fc 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -262,8 +262,11 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, icmph->ttl = BATADV_TTL;

res = batadv_send_skb_to_orig(skb, orig_node, NULL); - ret = NET_RX_SUCCESS; + if (res == NET_XMIT_SUCCESS) + ret = NET_RX_SUCCESS;

+ /* skb was consumed */ + skb = NULL; break; case BATADV_TP: if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet))) @@ -271,6 +274,8 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,

batadv_tp_meter_recv(bat_priv, skb); ret = NET_RX_SUCCESS; + /* skb was consumed */ + skb = NULL; goto out; default: /* drop unknown type */ @@ -281,6 +286,9 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, batadv_hardif_put(primary_if); if (orig_node) batadv_orig_node_put(orig_node); + + kfree_skb(skb); + return ret; }

@@ -322,13 +330,20 @@ static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, icmp_packet->ttl = BATADV_TTL;

res = batadv_send_skb_to_orig(skb, orig_node, NULL); - ret = NET_RX_SUCCESS; + if (res == NET_RX_SUCCESS) + ret = NET_XMIT_SUCCESS; + + /* skb was consumed */ + skb = NULL;

out: if (primary_if) batadv_hardif_put(primary_if); if (orig_node) batadv_orig_node_put(orig_node); + + kfree_skb(skb); + return ret; }

@@ -345,21 +360,21 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,

/* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, hdr_size))) - goto out; + goto free_skb;

ethhdr = eth_hdr(skb);

/* packet with unicast indication but broadcast recipient */ if (is_broadcast_ether_addr(ethhdr->h_dest)) - goto out; + goto free_skb;

/* packet with broadcast sender address */ if (is_broadcast_ether_addr(ethhdr->h_source)) - goto out; + goto free_skb;

/* not for me */ if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) - goto out; + goto free_skb;

icmph = (struct batadv_icmp_header *)skb->data;

@@ -368,17 +383,17 @@ int batadv_recv_icmp_packet(struct sk_buff *skb, icmph->msg_type == BATADV_ECHO_REQUEST) && (skb->len >= sizeof(struct batadv_icmp_packet_rr))) { if (skb_linearize(skb) < 0) - goto out; + goto free_skb;

/* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) - goto out; + goto free_skb;

ethhdr = eth_hdr(skb); icmph = (struct batadv_icmp_header *)skb->data; icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph; if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN) - goto out; + goto free_skb;

ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur], ethhdr->h_dest); @@ -396,11 +411,11 @@ int batadv_recv_icmp_packet(struct sk_buff *skb, /* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, icmph->dst); if (!orig_node) - goto out; + goto free_skb;

/* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) - goto out; + goto put_orig_node;

icmph = (struct batadv_icmp_header *)skb->data;

@@ -409,11 +424,18 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,

/* route it */ res = batadv_send_skb_to_orig(skb, orig_node, recv_if); - ret = NET_RX_SUCCESS; + if (res == NET_XMIT_SUCCESS) + ret = NET_RX_SUCCESS;

-out: + /* skb was consumed */ + skb = NULL; + +put_orig_node: if (orig_node) batadv_orig_node_put(orig_node); +free_skb: + kfree_skb(skb); + return ret; }

@@ -662,18 +684,18 @@ static int batadv_route_unicast_packet(struct sk_buff *skb, if (unicast_packet->ttl < 2) { pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", ethhdr->h_source, unicast_packet->dest); - goto out; + goto free_skb; }

/* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);

if (!orig_node) - goto out; + goto free_skb;

/* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) - goto out; + goto put_orig_node;

/* decrement ttl */ unicast_packet = (struct batadv_unicast_packet *)skb->data; @@ -697,6 +719,11 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,

len = skb->len; res = batadv_send_skb_to_orig(skb, orig_node, recv_if); + if (res == NET_XMIT_SUCCESS) + ret = NET_RX_SUCCESS; + + /* skb was consumed */ + skb = NULL;

/* translate transmit result into receive result */ if (res == NET_XMIT_SUCCESS) { @@ -706,11 +733,11 @@ static int batadv_route_unicast_packet(struct sk_buff *skb, len + ETH_HLEN); }

- ret = NET_RX_SUCCESS; +put_orig_node: + batadv_orig_node_put(orig_node); +free_skb: + kfree_skb(skb);

-out: - if (orig_node) - batadv_orig_node_put(orig_node); return ret; }

@@ -895,14 +922,18 @@ int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,

check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); if (check < 0) - return NET_RX_DROP; + goto free_skb;

/* we don't know about this type, drop it. */ unicast_packet = (struct batadv_unicast_packet *)skb->data; if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) - return NET_RX_DROP; + goto free_skb;

return batadv_route_unicast_packet(skb, recv_if); + +free_skb: + kfree_skb(skb); + return NET_RX_DROP; }

int batadv_recv_unicast_packet(struct sk_buff *skb, @@ -916,6 +947,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; bool is4addr; + int ret = NET_RX_DROP;

unicast_packet = (struct batadv_unicast_packet *)skb->data; unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; @@ -935,9 +967,9 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);

if (check < 0) - return NET_RX_DROP; + goto free_skb; if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) - return NET_RX_DROP; + goto free_skb;

/* packet for me */ if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { @@ -975,7 +1007,14 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, return NET_RX_SUCCESS; }

- return batadv_route_unicast_packet(skb, recv_if); + ret = batadv_route_unicast_packet(skb, recv_if); + /* skb was consumed */ + skb = NULL; + +free_skb: + kfree_skb(skb); + + return ret; }

/** @@ -997,15 +1036,15 @@ int batadv_recv_unicast_tvlv(struct sk_buff *skb, int ret = NET_RX_DROP;

if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) - return NET_RX_DROP; + goto free_skb;

/* the header is likely to be modified while forwarding */ if (skb_cow(skb, hdr_size) < 0) - return NET_RX_DROP; + goto free_skb;

/* packet needs to be linearized to access the tvlv content */ if (skb_linearize(skb) < 0) - return NET_RX_DROP; + goto free_skb;

unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;

@@ -1013,17 +1052,21 @@ int batadv_recv_unicast_tvlv(struct sk_buff *skb, tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);

if (tvlv_buff_len > skb->len - hdr_size) - return NET_RX_DROP; + goto free_skb;

ret = batadv_tvlv_containers_process(bat_priv, false, NULL, unicast_tvlv_packet->src, unicast_tvlv_packet->dst, tvlv_buff, tvlv_buff_len);

- if (ret != NET_RX_SUCCESS) + if (ret != NET_RX_SUCCESS) { ret = batadv_route_unicast_packet(skb, recv_if); - else - consume_skb(skb); + /* skb was consumed */ + skb = NULL; + } + +free_skb: + kfree_skb(skb);

return ret; } @@ -1049,20 +1092,22 @@ int batadv_recv_frag_packet(struct sk_buff *skb,

if (batadv_check_unicast_packet(bat_priv, skb, sizeof(*frag_packet)) < 0) - goto out; + goto free_skb;

frag_packet = (struct batadv_frag_packet *)skb->data; orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig); if (!orig_node_src) - goto out; + goto free_skb;

skb->priority = frag_packet->priority + 256;

/* Route the fragment if it is not for us and too big to be merged. */ if (!batadv_is_my_mac(bat_priv, frag_packet->dest) && batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) { + /* skb was consumed */ + skb = NULL; ret = NET_RX_SUCCESS; - goto out; + goto put_orig_node; }

batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX); @@ -1070,20 +1115,24 @@ int batadv_recv_frag_packet(struct sk_buff *skb,

/* Add fragment to buffer and merge if possible. */ if (!batadv_frag_skb_buffer(&skb, orig_node_src)) - goto out; + goto put_orig_node;

/* Deliver merged packet to the appropriate handler, if it was * merged */ - if (skb) + if (skb) { batadv_batman_skb_recv(skb, recv_if->net_dev, &recv_if->batman_adv_ptype, NULL); + /* skb was consumed */ + skb = NULL; + }

ret = NET_RX_SUCCESS;

-out: - if (orig_node_src) - batadv_orig_node_put(orig_node_src); +put_orig_node: + batadv_orig_node_put(orig_node_src); +free_skb: + kfree_skb(skb);

return ret; } @@ -1102,35 +1151,35 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,

/* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, hdr_size))) - goto out; + goto free_skb;

ethhdr = eth_hdr(skb);

/* packet with broadcast indication but unicast recipient */ if (!is_broadcast_ether_addr(ethhdr->h_dest)) - goto out; + goto free_skb;

/* packet with broadcast sender address */ if (is_broadcast_ether_addr(ethhdr->h_source)) - goto out; + goto free_skb;

/* ignore broadcasts sent by myself */ if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) - goto out; + goto free_skb;

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

/* ignore broadcasts originated by myself */ if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) - goto out; + goto free_skb;

if (bcast_packet->ttl < 2) - goto out; + goto free_skb;

orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);

if (!orig_node) - goto out; + goto free_skb;

spin_lock_bh(&orig_node->bcast_seqno_lock);

@@ -1158,7 +1207,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,

/* check whether this has been sent by another originator before */ if (batadv_bla_check_bcast_duplist(bat_priv, skb)) - goto out; + goto free_skb;

batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));

@@ -1169,7 +1218,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb, * from the same backbone. */ if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) - goto out; + goto free_skb;

if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) goto rx_success; @@ -1185,6 +1234,8 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,

spin_unlock: spin_unlock_bh(&orig_node->bcast_seqno_lock); +free_skb: + kfree_skb(skb); out: if (orig_node) batadv_orig_node_put(orig_node);