[B.A.T.M.A.N.] [RFC 5/6] batman-adv: to_meter - add option to perform one-hop test

From: Antonio Quartulli a@unstable.cc

A link test is a TP session ran over a specific one-hop link, rather than towards an originator in the mesh.

Signed-off-by: Antonio Quartulli a@unstable.cc --- include/uapi/linux/batadv_packet.h | 1 + net/batman-adv/netlink.c | 3 +- net/batman-adv/routing.c | 5 +- net/batman-adv/tp_meter.c | 220 +++++++++++++++++++---------- net/batman-adv/tp_meter.h | 8 +- net/batman-adv/types.h | 3 + 6 files changed, 161 insertions(+), 79 deletions(-)

diff --git a/include/uapi/linux/batadv_packet.h b/include/uapi/linux/batadv_packet.h index 894d8d2f..fc89ab6b 100644 --- a/include/uapi/linux/batadv_packet.h +++ b/include/uapi/linux/batadv_packet.h @@ -355,6 +355,7 @@ struct batadv_icmp_tp_packet { enum batadv_icmp_tp_subtype { BATADV_TP_MSG = 0, BATADV_TP_ACK, + BATADV_TP_MSG_LINK, };

#define BATADV_RR_LEN 16 diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c index 88bf6c6f..064020cc 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -378,7 +378,8 @@ batadv_netlink_tp_meter_start(struct sk_buff *skb, struct genl_info *info) }

bat_priv = netdev_priv(soft_iface); - batadv_tp_start(bat_priv, dst, test_length, &cookie, BATADV_TP_USERSPACE); + batadv_tp_start(bat_priv, dst, NULL, test_length, &cookie, + BATADV_TP_USERSPACE);

ret = batadv_netlink_tp_meter_put(msg, cookie);

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index cc3ed93a..2a2c1ffe 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -229,6 +229,7 @@ bool batadv_check_management_packet(struct sk_buff *skb, * otherwise. */ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, + struct batadv_hard_iface *recv_if, struct sk_buff *skb) { struct batadv_hard_iface *primary_if = NULL; @@ -281,7 +282,7 @@ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet))) goto out;

- batadv_tp_meter_recv(bat_priv, skb); + batadv_tp_meter_recv(bat_priv, recv_if, skb); ret = NET_RX_SUCCESS; /* skb was consumed */ skb = NULL; @@ -418,7 +419,7 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,

/* packet for me */ if (batadv_is_my_mac(bat_priv, icmph->dst)) - return batadv_recv_my_icmp_packet(bat_priv, skb); + return batadv_recv_my_icmp_packet(bat_priv, recv_if, skb);

/* TTL exceeded */ if (icmph->ttl < 2) diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index f7bb45d3..1526286b 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -378,6 +378,9 @@ static void batadv_tp_vars_release(struct kref *ref) } spin_unlock_bh(&tp_vars->unacked_lock);

+ if (tp_vars->hardif_neigh) + batadv_hardif_neigh_put(tp_vars->hardif_neigh); + kfree_rcu(tp_vars, rcu); }

@@ -591,26 +594,57 @@ static void batadv_tp_fill_prerandom(struct batadv_tp_vars *tp_vars, * not reachable, BATADV_TP_REASON_MEMORY_ERROR if the packet couldn't be * allocated */ -static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, - struct batadv_orig_node *orig_node, - u32 seqno, size_t len, const u8 *session, - int uid, u32 timestamp) +static int batadv_tp_send_msg(struct batadv_priv *bat_priv, + struct batadv_tp_vars *tp_vars, u32 seqno, + size_t len, const u8 *session, int uid, + u32 timestamp) { + struct batadv_hard_iface *primary_if = NULL; + struct batadv_orig_node *orig_node = NULL; struct batadv_icmp_tp_packet *icmp; struct sk_buff *skb; - int r; - u8 *data; + int r, ret = 0; + u8 *data, *src, *dst, subtype; + struct net_device *netdev; size_t data_len;

- skb = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN); - if (unlikely(!skb)) - return BATADV_TP_REASON_MEMORY_ERROR; + /* link test */ + if (tp_vars->hardif_neigh) { + dst = tp_vars->hardif_neigh->addr; + src = tp_vars->hardif_neigh->if_incoming->net_dev->dev_addr; + subtype = BATADV_TP_MSG_LINK; + netdev = tp_vars->hardif_neigh->if_incoming->net_dev; + } else { + orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); + if (unlikely(!orig_node)) { + ret = BATADV_TP_REASON_DST_UNREACHABLE; + goto out; + } + + + primary_if = batadv_primary_if_get_selected(bat_priv); + if (unlikely(!primary_if)) { + ret = BATADV_TP_REASON_DST_UNREACHABLE; + goto out; + } + + dst = orig_node->orig; + src = primary_if->net_dev->dev_addr; + subtype = BATADV_TP_MSG; + netdev = NULL; + } + + skb = netdev_alloc_skb_ip_align(netdev, len + ETH_HLEN); + if (unlikely(!skb)) { + ret = BATADV_TP_REASON_MEMORY_ERROR; + goto out; + }

skb_reserve(skb, ETH_HLEN); icmp = skb_put(skb, sizeof(*icmp));

/* fill the icmp header */ - ether_addr_copy(icmp->dst, orig_node->orig); + ether_addr_copy(icmp->dst, dst); ether_addr_copy(icmp->orig, src); icmp->version = BATADV_COMPAT_VERSION; icmp->packet_type = BATADV_ICMP; @@ -618,7 +652,7 @@ static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, icmp->msg_type = BATADV_TP; icmp->uid = uid;

- icmp->subtype = BATADV_TP_MSG; + icmp->subtype = subtype; memcpy(icmp->session, session, sizeof(icmp->session)); icmp->seqno = htonl(seqno); icmp->timestamp = htonl(timestamp); @@ -627,11 +661,23 @@ static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, data = skb_put(skb, data_len); batadv_tp_fill_prerandom(tp_vars, data, data_len);

- r = batadv_send_skb_to_orig(skb, orig_node, NULL); - if (r == NET_XMIT_SUCCESS) - return 0; + if (tp_vars->hardif_neigh) + r = batadv_send_skb_packet(skb, + tp_vars->hardif_neigh->if_incoming, + dst); + else + r = batadv_send_skb_to_orig(skb, orig_node, NULL); + + if (unlikely(r != NET_XMIT_SUCCESS)) + ret = BATADV_TP_REASON_CANT_SEND;

- return BATADV_TP_REASON_CANT_SEND; +out: + if (likely(primary_if)) + batadv_hardif_put(primary_if); + if (likely(orig_node)) + batadv_orig_node_put(orig_node); + + return ret; }

/** @@ -650,7 +696,6 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, struct batadv_tp_vars *tp_vars; size_t packet_len, mss; u32 rtt, recv_ack, cwnd; - unsigned char *dev_addr;

packet_len = BATADV_TP_PLEN; mss = BATADV_TP_PLEN; @@ -672,13 +717,11 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, (u32)atomic_read(&tp_vars->last_acked))) goto out;

- primary_if = batadv_primary_if_get_selected(bat_priv); - if (unlikely(!primary_if)) - goto out; - - orig_node = batadv_orig_hash_find(bat_priv, icmp->orig); - if (unlikely(!orig_node)) - goto out; + if (!tp_vars->hardif_neigh) { + primary_if = batadv_primary_if_get_selected(bat_priv); + if (unlikely(!primary_if)) + goto out; + }

/* update RTO with the new sampled RTT, if any */ rtt = jiffies_to_msecs(jiffies) - ntohl(icmp->timestamp); @@ -700,8 +743,11 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, goto out;

/* if this is the third duplicate ACK do Fast Retransmit */ - batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, - orig_node, recv_ack, packet_len, + + /* if we have a hardif_neigh, it means that this is a LINK test, + * therefore use the according function + */ + batadv_tp_send_msg(bat_priv, tp_vars, recv_ack, packet_len, icmp->session, icmp->uid, jiffies_to_msecs(jiffies));

@@ -738,9 +784,7 @@ static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, * immediately as specified by NewReno (see * Section 3.2 of RFC6582 for details) */ - dev_addr = primary_if->net_dev->dev_addr; - batadv_tp_send_msg(tp_vars, dev_addr, - orig_node, recv_ack, + batadv_tp_send_msg(bat_priv, tp_vars, recv_ack, packet_len, icmp->session, icmp->uid, jiffies_to_msecs(jiffies)); @@ -824,8 +868,6 @@ static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen) */ static void batadv_tp_send(struct work_struct *work) { - struct batadv_hard_iface *primary_if = NULL; - struct batadv_orig_node *orig_node = NULL; struct batadv_tp_vars *tp_vars; size_t payload_len, packet_len; struct batadv_priv *bat_priv; @@ -840,20 +882,6 @@ static void batadv_tp_send(struct work_struct *work) goto out; }

- orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); - if (unlikely(!orig_node)) { - err = BATADV_TP_REASON_DST_UNREACHABLE; - tp_vars->reason = err; - goto out; - } - - primary_if = batadv_primary_if_get_selected(bat_priv); - if (unlikely(!primary_if)) { - err = BATADV_TP_REASON_DST_UNREACHABLE; - tp_vars->reason = err; - goto out; - } - /* assume that all the hard_interfaces have a correctly * configured MTU, so use the soft_iface MTU as MSS. * This might not be true and in that case the fragmentation @@ -880,10 +908,9 @@ static void batadv_tp_send(struct work_struct *work) */ packet_len = payload_len + sizeof(struct batadv_unicast_packet);

- err = batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, - orig_node, tp_vars->last_sent, - packet_len, - tp_vars->session, tp_vars->icmp_uid, + err = batadv_tp_send_msg(bat_priv, tp_vars, tp_vars->last_sent, + packet_len, tp_vars->session, + tp_vars->icmp_uid, jiffies_to_msecs(jiffies));

/* something went wrong during the preparation/transmission */ @@ -905,11 +932,6 @@ static void batadv_tp_send(struct work_struct *work) }

out: - if (likely(primary_if)) - batadv_hardif_put(primary_if); - if (likely(orig_node)) - batadv_orig_node_put(orig_node); - batadv_tp_sender_end(bat_priv, tp_vars); batadv_tp_sender_cleanup(bat_priv, tp_vars);

@@ -936,17 +958,20 @@ static void batadv_tp_start_work(struct batadv_tp_vars *tp_vars) * @caller: caller of tp meter session (user space or ELP) */ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, + struct batadv_hardif_neigh_node *neigh, u32 test_length, u32 *cookie, enum batadv_tp_meter_caller caller) { struct batadv_tp_vars *tp_vars; u8 session_id[2]; u8 icmp_uid; - u32 session_cookie; + u32 session_cookie = 0;

get_random_bytes(session_id, sizeof(session_id)); get_random_bytes(&icmp_uid, 1); - session_cookie = batadv_tp_session_cookie(session_id, icmp_uid); - *cookie = session_cookie; + if (cookie) { + session_cookie = batadv_tp_session_cookie(session_id, icmp_uid); + *cookie = session_cookie; + }

if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM_QUEUE)) { spin_unlock_bh(&bat_priv->tp_list_lock); @@ -969,6 +994,10 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,

/* initialize tp_vars */ ether_addr_copy(tp_vars->other_end, dst); + if (neigh) { + kref_get(&neigh->refcount); + tp_vars->hardif_neigh = neigh; + } kref_init(&tp_vars->refcount); tp_vars->role = BATADV_TP_SENDER; tp_vars->caller = caller; @@ -1139,29 +1168,42 @@ static void batadv_tp_receiver_shutdown(struct timer_list *t) * Return: 0 on success, a positive integer representing the reason of the * failure otherwise */ -static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst, +static int batadv_tp_send_ack(struct batadv_priv *bat_priv, + struct batadv_tp_vars *tp_vars, u32 seq, __be32 timestamp, const u8 *session, int socket_index) { struct batadv_hard_iface *primary_if = NULL; - struct batadv_orig_node *orig_node; + struct batadv_orig_node *orig_node = NULL; struct batadv_icmp_tp_packet *icmp; + struct net_device *netdev = NULL; struct sk_buff *skb; + u8 *src, *dst; int r, ret;

- orig_node = batadv_orig_hash_find(bat_priv, dst); - if (unlikely(!orig_node)) { - ret = BATADV_TP_REASON_DST_UNREACHABLE; - goto out; - } + if (tp_vars->hardif_neigh) { + dst = tp_vars->hardif_neigh->addr; + src = tp_vars->hardif_neigh->if_incoming->net_dev->dev_addr; + netdev = tp_vars->hardif_neigh->if_incoming->net_dev; + } else { + orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); + if (unlikely(!orig_node)) { + ret = BATADV_TP_REASON_DST_UNREACHABLE; + goto out; + }

- primary_if = batadv_primary_if_get_selected(bat_priv); - if (unlikely(!primary_if)) { - ret = BATADV_TP_REASON_DST_UNREACHABLE; - goto out; + primary_if = batadv_primary_if_get_selected(bat_priv); + if (unlikely(!primary_if)) { + ret = BATADV_TP_REASON_DST_UNREACHABLE; + goto out; + } + + dst = orig_node->orig; + src = primary_if->net_dev->dev_addr; + netdev = NULL; }

- skb = netdev_alloc_skb_ip_align(NULL, sizeof(*icmp) + ETH_HLEN); + skb = netdev_alloc_skb_ip_align(netdev, sizeof(*icmp) + ETH_HLEN); if (unlikely(!skb)) { ret = BATADV_TP_REASON_MEMORY_ERROR; goto out; @@ -1183,7 +1225,13 @@ static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst, icmp->timestamp = timestamp;

/* send the ack */ - r = batadv_send_skb_to_orig(skb, orig_node, NULL); + if (tp_vars->hardif_neigh) + r = batadv_send_skb_packet(skb, + tp_vars->hardif_neigh->if_incoming, + dst); + else + r = batadv_send_skb_to_orig(skb, orig_node, NULL); + if (unlikely(r < 0) || r == NET_XMIT_DROP) { ret = BATADV_TP_REASON_DST_UNREACHABLE; goto out; @@ -1317,8 +1365,10 @@ static void batadv_tp_ack_unordered(struct batadv_tp_vars *tp_vars) */ static struct batadv_tp_vars * batadv_tp_init_recv(struct batadv_priv *bat_priv, + struct batadv_hard_iface *recv_if, const struct batadv_icmp_tp_packet *icmp) { + struct batadv_hardif_neigh_node *neigh = NULL; struct batadv_tp_vars *tp_vars;

spin_lock_bh(&bat_priv->tp_list_lock); @@ -1333,15 +1383,30 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, goto out_unlock; }

+ /* the sender is starting a LINK test, therefore we have retrieve its + * corresponding hardif_neigh_node that we'll use later to send ACKs + * back + */ + if (icmp->subtype == BATADV_TP_MSG_LINK) { + neigh = batadv_hardif_neigh_get(recv_if, icmp->orig); + if (!neigh) { + batadv_dbg(BATADV_DBG_TP_METER, bat_priv, + "Meter: %s() can't retrieve sender neigh object for %pM\n", + __func__, icmp->orig); + goto out_unlock; + } + } + tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); if (!tp_vars) - goto out_unlock; + goto err_neigh_put;

ether_addr_copy(tp_vars->other_end, icmp->orig); tp_vars->role = BATADV_TP_RECEIVER; memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session)); tp_vars->last_recv = BATADV_TP_FIRST_SEQ; tp_vars->bat_priv = bat_priv; + tp_vars->hardif_neigh = neigh; kref_init(&tp_vars->refcount);

spin_lock_init(&tp_vars->unacked_lock); @@ -1354,7 +1419,10 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, timer_setup(&tp_vars->timer, batadv_tp_receiver_shutdown, 0);

batadv_tp_reset_receiver_timer(tp_vars); + goto out_unlock;

+err_neigh_put: + batadv_hardif_neigh_put(neigh); out_unlock: spin_unlock_bh(&bat_priv->tp_list_lock);

@@ -1369,6 +1437,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv, * Process a received TP MSG packet */ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, + struct batadv_hard_iface *recv_if, const struct sk_buff *skb) { const struct batadv_icmp_tp_packet *icmp; @@ -1383,7 +1452,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, * first packet is lost, the tp meter does not work anymore! */ if (seqno == BATADV_TP_FIRST_SEQ) { - tp_vars = batadv_tp_init_recv(bat_priv, icmp); + tp_vars = batadv_tp_init_recv(bat_priv, recv_if, icmp); if (!tp_vars) { batadv_dbg(BATADV_DBG_TP_METER, bat_priv, "Meter: seqno != BATADV_TP_FIRST_SEQ cannot initiate connection\n"); @@ -1439,7 +1508,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, * is going to be sent is a duplicate (the sender will count them and * possibly enter Fast Retransmit as soon as it has reached 3) */ - batadv_tp_send_ack(bat_priv, icmp->orig, tp_vars->last_recv, + batadv_tp_send_ack(bat_priv, tp_vars, tp_vars->last_recv, icmp->timestamp, icmp->session, icmp->uid); out: if (likely(tp_vars)) @@ -1451,7 +1520,9 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, * @bat_priv: the bat priv with all the soft interface information * @skb: the buffer containing the received packet */ -void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb) +void batadv_tp_meter_recv(struct batadv_priv *bat_priv, + struct batadv_hard_iface *recv_if, + struct sk_buff *skb) { struct batadv_icmp_tp_packet *icmp;

@@ -1459,7 +1530,8 @@ void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb)

switch (icmp->subtype) { case BATADV_TP_MSG: - batadv_tp_recv_msg(bat_priv, skb); + case BATADV_TP_MSG_LINK: + batadv_tp_recv_msg(bat_priv, recv_if, skb); break; case BATADV_TP_ACK: batadv_tp_recv_ack(bat_priv, skb); diff --git a/net/batman-adv/tp_meter.h b/net/batman-adv/tp_meter.h index d844575d..3a1be483 100644 --- a/net/batman-adv/tp_meter.h +++ b/net/batman-adv/tp_meter.h @@ -28,9 +28,13 @@ struct sk_buff; int batadv_tp_meter_init(void); void batadv_tp_meter_destroy(void); void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, - u32 test_length, u32 *cookie, enum batadv_tp_meter_caller caller); + struct batadv_hardif_neigh_node *neigh, + u32 test_length, u32 *cookie, + enum batadv_tp_meter_caller caller); void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, u8 return_value); -void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb); +void batadv_tp_meter_recv(struct batadv_priv *bat_priv, + struct batadv_hard_iface *recv_if, + struct sk_buff *skb);

#endif /* _NET_BATMAN_ADV_TP_METER_H_ */ diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 826b3b42..98dccc6c 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1454,6 +1454,9 @@ struct batadv_tp_vars {

/** @rcu: struct used for freeing in an RCU-safe manner */ struct rcu_head rcu; + + /** @neigh_node: in case of LINK test, represents the other-end */ + struct batadv_hardif_neigh_node *hardif_neigh; };

/**