B.A.T.M.A.N

b.a.t.m.a.n@lists.open-mesh.org

15 participants
4308 discussions

[B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: fix backbone_gw refcount on queue_work() failure
by Marek Lindner 07 Sep '18

07 Sep '18

The backbone_gw refcounter is to be decreased by the queued work and currently is never decreased if the queue_work() call fails. Fix by checking the queue_work() return value and decrease refcount if necessary. Signed-off-by: Marek Lindner <mareklindner(a)neomailbox.ch> --- net/batman-adv/bridge_loop_avoidance.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index a2de5a44..58c093ca 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1772,6 +1772,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, { struct batadv_bla_backbone_gw *backbone_gw; struct ethhdr *ethhdr; + bool ret; ethhdr = eth_hdr(skb); @@ -1795,8 +1796,13 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, if (unlikely(!backbone_gw)) return true; - queue_work(batadv_event_workqueue, &backbone_gw->report_work); - /* backbone_gw is unreferenced in the report work function function */ + ret = queue_work(batadv_event_workqueue, &backbone_gw->report_work); + + /* backbone_gw is unreferenced in the report work function function + * if queue_work() call was successful + */ + if (!ret) + batadv_backbone_gw_put(backbone_gw); return true; } -- 2.18.0

2 2

[B.A.T.M.A.N.] [PATCH v2 0/5] batman-adv: Missing list checks for *list_add*
by Sven Eckelmann 07 Sep '18

07 Sep '18

Hi, Marek reviewed the the previous version of the patcheset [0] and requested some changes for patch 1 and 3. * patch 1: - added kerneldoc about the locking requirements * patch 3 - changed batadv_softif_create_vlan to handle problems in batadv_sysfs_add_vlan as fatal error Kind regards, Sven [0] https://patchwork.open-mesh.org/project/b.a.t.m.a.n./list/?series=150&submi… [1] https://www.open-mesh.org/issues/235 [2] https://www.open-mesh.org/issues/236 [3] https://www.open-mesh.org/issues/237 [4] https://www.open-mesh.org/issues/238 [5] https://www.open-mesh.org/issues/239 [6] https://www.open-mesh.org/issues/240 [7] https://www.open-mesh.org/issues/241 [8] https://patchwork.open-mesh.org/patch/4919/ net/batman-adv/gateway_client.c | 11 +++++++++-- net/batman-adv/network-coding.c | 27 +++++++++++++++------------ net/batman-adv/soft-interface.c | 25 ++++++++++++++++++------- net/batman-adv/translation-table.c | 6 ++++-- net/batman-adv/tvlv.c | 8 ++++++-- 5 files changed, 52 insertions(+), 25 deletions(-) -- 2.11.0

1 6

[B.A.T.M.A.N.] [PATCH v6] batman-adv: Snoop DHCPACKs for DAT
by Linus Lüssing 06 Sep '18

06 Sep '18

In a 1000 nodes mesh network (Freifunk Hamburg) we can still see 30KBit/s of ARP traffic (equalling about 25% of all layer two specific overhead, remaining after some filtering) flooded through the mesh. These 30KBit/s are mainly ARP Requests from the gateways / DHCP servers. By snooping DHCPACKs we can learn about MAC/IP address pairs in the DHCP range without relying on ARP. This patch is in preparation to eliminate the need for mesh wide message flooding for IPv4 address resolution. Also this allows to quickly update a MAC/IP pair at least in the DHT when DHCP reassigns an IP address to a new host. Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Changes in v6: * moved dhcp packet definition from batadv_packet.h to distributed-arp-table.c Changes in v5: * fixed unaligned access issues (that is, enforce a two step load via "get_unaligned") for DHCP magic and yiaddr fields * simplified batadv_dat_put_pairs(): there is no need to check that arp_create() set the ARP type correctly. It always does or returns NULL otherwise. (this also fixes another unaligned access) Changes in v4: * Removed @proto from kerneldoc * Less enum values in batadv_packet.h * Moved skb_set_network_header() call * Updated commit message Changes in v3: * Rebase to master * Shortened commit message Changes in v2: * Rebase to master * Fix compilation with CONFIG_BATMAN_ADV=n (added stubs) Changes in RFC -> non-RFC * Added kerneldoc * Added Signed-off-by * More IP Header checks (iph->hlen considered, ip version checked, ...) * Parsing & checking DHCP Message Type Option, only snooping DHCPACKs now * Moved ethernet protocol check from batadv_dat_check_dhcp to batadv_dat_check_dhcp_ipudp * Removed buffer-length parameter from batadv_dat_dhcp_get_{yiaddr,chaddr}() * Renamed batadv_dat_put() to batadv_dat_put_pairs() fixup DAT DHCP snooping --- net/batman-adv/distributed-arp-table.c | 326 +++++++++++++++++++++++++++++++++ net/batman-adv/distributed-arp-table.h | 11 ++ net/batman-adv/soft-interface.c | 11 +- 3 files changed, 346 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index a60bacf7..401f4065 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -29,6 +29,7 @@ #include <linux/if_ether.h> #include <linux/if_vlan.h> #include <linux/in.h> +#include <linux/ip.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> @@ -42,9 +43,11 @@ #include <linux/spinlock.h> #include <linux/stddef.h> #include <linux/string.h> +#include <linux/udp.h> #include <linux/workqueue.h> #include <net/arp.h> #include <net/genetlink.h> +#include <net/ip.h> #include <net/netlink.h> #include <net/sock.h> #include <uapi/linux/batman_adv.h> @@ -60,6 +63,46 @@ #include "translation-table.h" #include "tvlv.h" +enum batadv_bootpop { + BATADV_BOOTREPLY = 2, +}; + +enum batadv_boothtype { + BATADV_HTYPE_ETHERNET = 1, +}; + +enum batadv_dhcpoptioncode { + BATADV_DHCP_OPT_PAD = 0, + BATADV_DHCP_OPT_MSG_TYPE = 53, + BATADV_DHCP_OPT_END = 255, +}; + +enum batadv_dhcptype { + BATADV_DHCPACK = 5, +}; + +/* { 99, 130, 83, 99 } */ +#define BATADV_DHCP_MAGIC 1669485411 + +struct batadv_dhcp_packet { + __u8 op; + __u8 htype; + __u8 hlen; + __u8 hops; + __be32 xid; + __be16 secs; + __be16 flags; + __be32 ciaddr; + __be32 yiaddr; + __be32 siaddr; + __be32 giaddr; + __u8 chaddr[16]; + __u8 sname[64]; + __u8 file[128]; + __be32 magic; + __u8 options[0]; +}; + static void batadv_dat_purge(struct work_struct *work); /** @@ -1436,6 +1479,289 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, } /** + * batadv_dat_check_dhcp_ipudp() - check skb for IP+UDP headers valid for DHCP + * @skb: the packet to check + * + * Checks whether the given skb has an IP and UDP header valid for a DHCP + * message from a DHCP server. + * + * Return: True if valid, false otherwise. + */ +static bool batadv_dat_check_dhcp_ipudp(struct sk_buff *skb) +{ + struct iphdr *iphdr, _iphdr; + struct udphdr *udphdr, _udphdr; + unsigned int offset = skb_network_offset(skb); + + iphdr = skb_header_pointer(skb, offset, sizeof(_iphdr), &_iphdr); + if (!iphdr || iphdr->version != 4 || ip_hdrlen(skb) < sizeof(_iphdr)) + return false; + + if (iphdr->protocol != IPPROTO_UDP) + return false; + + offset += ip_hdrlen(skb); + skb_set_transport_header(skb, offset); + + udphdr = skb_header_pointer(skb, offset, sizeof(_udphdr), &_udphdr); + if (!udphdr || udphdr->source != htons(67)) + return false; + + return true; +} + +/** + * batadv_dat_check_dhcp() - examine packet for valid DHCP message + * @skb: the packet to check + * @proto: ethernet protocol hint (behind a potential vlan) + * + * Checks whether the given skb is a valid DHCP packet. + * + * Caller needs to ensure that the skb network header is set correctly. + * + * Return: If skb is a valid DHCP packet, then returns its op code + * (e.g. BOOTREPLY vs. BOOTREQUEST). Otherwise returns -EINVAL. + */ +static int batadv_dat_check_dhcp(struct sk_buff *skb, __be16 proto) +{ + u8 *op, _op; + u8 *htype, _htype; + u8 *hlen, _hlen; + __be32 *magic, _magic; + unsigned int dhcp_offset; + unsigned int offset; + + if (proto != htons(ETH_P_IP)) + return -EINVAL; + + if (!batadv_dat_check_dhcp_ipudp(skb)) + return -EINVAL; + + dhcp_offset = skb_transport_offset(skb) + sizeof(struct udphdr); + if (skb->len < dhcp_offset + sizeof(struct batadv_dhcp_packet)) + return -EINVAL; + + offset = dhcp_offset + offsetof(struct batadv_dhcp_packet, op); + + op = skb_header_pointer(skb, offset, sizeof(_op), &_op); + if (!op) + return -EINVAL; + + offset = dhcp_offset + offsetof(struct batadv_dhcp_packet, htype); + + htype = skb_header_pointer(skb, offset, sizeof(_htype), &_htype); + if (!htype || *htype != BATADV_HTYPE_ETHERNET) + return -EINVAL; + + offset = dhcp_offset + offsetof(struct batadv_dhcp_packet, hlen); + + hlen = skb_header_pointer(skb, offset, sizeof(_hlen), &_hlen); + if (!hlen || *hlen != ETH_ALEN) + return -EINVAL; + + offset = dhcp_offset + offsetof(struct batadv_dhcp_packet, magic); + + magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic); + if (!magic || get_unaligned(magic) != htonl(BATADV_DHCP_MAGIC)) + return -EINVAL; + + return *op; +} + +/** + * batadv_dat_get_dhcp_message_type() - get message type of a DHCP packet + * @skb: the DHCP packet to parse + * + * Iterates over the DHCP options of the given DHCP packet to find a + * DHCP Message Type option and parse it. + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: The found DHCP message type value, if found. -EINVAL otherwise. + */ +static int batadv_dat_get_dhcp_message_type(struct sk_buff *skb) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + u8 *type, _type; + struct { + u8 type; + u8 len; + } *tl, _tl; + + offset += sizeof(struct batadv_dhcp_packet); + + while ((tl = skb_header_pointer(skb, offset, sizeof(_tl), &_tl))) { + if (tl->type == BATADV_DHCP_OPT_MSG_TYPE) + break; + + if (tl->type == BATADV_DHCP_OPT_END) + break; + + if (tl->type == BATADV_DHCP_OPT_PAD) + offset++; + else + offset += tl->len + sizeof(_tl); + } + + /* Option Overload Code not supported */ + if (!tl || tl->type != BATADV_DHCP_OPT_MSG_TYPE || + tl->len != sizeof(_type)) + return -EINVAL; + + offset += sizeof(_tl); + + type = skb_header_pointer(skb, offset, sizeof(_type), &_type); + if (!type) + return -EINVAL; + + return *type; +} + +/** + * batadv_dat_get_dhcp_yiaddr() - get yiaddr from a DHCP packet + * @skb: the DHCP packet to parse + * @buffer: a buffer to store the yiaddr in (if necessary / skb is non-linear) + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: A safely accessible "Your IP Address" field from the provided DHCP + * packet. + */ +static __be32 *batadv_dat_dhcp_get_yiaddr(struct sk_buff *skb, __be32 *buffer) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + unsigned int len = sizeof(((struct batadv_dhcp_packet *)0)->yiaddr); + + offset += offsetof(struct batadv_dhcp_packet, yiaddr); + + return skb_header_pointer(skb, offset, len, buffer); +} + +/** + * batadv_dat_get_dhcp_chaddr() - get chaddr from a DHCP packet + * @skb: the DHCP packet to parse + * @buffer: a buffer to store the chaddr in (if necessary / skb is non-linear) + * + * Caller needs to ensure that the given skb is a valid DHCP packet and + * that the skb transport header is set correctly. + * + * Return: A safely accessible "Client Hardware Address" field from the provided + * DHCP packet. + */ +static u8 *batadv_dat_get_dhcp_chaddr(struct sk_buff *skb, u8 *buffer) +{ + unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr); + unsigned int len = sizeof(((struct batadv_dhcp_packet *)0)->chaddr); + + offset += offsetof(struct batadv_dhcp_packet, chaddr); + + return skb_header_pointer(skb, offset, len, buffer); +} + +/** + * batadv_dat_put_pairs() - puts two MAC/IP pairs into the DHT and DAT cache + * @bat_priv: the bat priv with all the soft interface information + * @hw_src: first value of DHT and ARP sender MAC + * @ip_src: first key of DHT and ARP sender IP + * @hw_dst: second value of DHT and ARP target MAC + * @ip_dst: second key of DHT and ARP target IP + * @vid: VLAN identifier + * + * Adds given MAC/IP pairs to the local DAT cache and propagates them further + * into the DHT. + * + * For the DHT propagation, hw_src/ip_src will appear as the ARP Reply + * transmitter (and hw_dst/ip_dst as the target). + * + * Return: True on success, false otherwise. + */ +static bool batadv_dat_put_pairs(struct batadv_priv *bat_priv, u8 *hw_src, + __be32 ip_src, u8 *hw_dst, __be32 ip_dst, + unsigned short vid) +{ + struct sk_buff *skb; + int hdr_size; + + skb = batadv_dat_arp_create_reply(bat_priv, ip_src, ip_dst, hw_src, + hw_dst, vid); + if (!skb) + return false; + + /* Check for validity of provided addresses */ + skb_set_network_header(skb, ETH_HLEN); + hdr_size = skb_network_offset(skb) - ETH_HLEN; + + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + + batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT); + batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); + + return true; +} + +/** + * batadv_dat_snoop_outgoing_dhcp_ack() - snoop DHCPACK and fill DAT with it + * @bat_priv: the bat priv with all the soft interface information + * @skb: the packet to snoop + * @proto: ethernet protocol hint (behind a potential vlan) + * @vid: VLAN identifier + * + * This function first checks whether the given skb is a valid DHCPACK. If + * so then its source MAC and IP as well as its DHCP Client Hardware Address + * field and DHCP Your IP Address field are added to the local DAT cache and + * propagated into the DHT. + * + * Caller needs to ensure that the skb mac and network headers are set + * correctly. + */ +void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, + struct sk_buff *skb, + __be16 proto, + unsigned short vid) +{ + int type; + u8 *chaddr, _chaddr[ETH_ALEN]; + __be32 *yiaddr, _yiaddr; + + if (!atomic_read(&bat_priv->distributed_arp_table)) + return; + + if (batadv_dat_check_dhcp(skb, proto) != BATADV_BOOTREPLY) + return; + + type = batadv_dat_get_dhcp_message_type(skb); + if (type != BATADV_DHCPACK) + return; + + yiaddr = batadv_dat_dhcp_get_yiaddr(skb, &_yiaddr); + if (!yiaddr) + return; + + chaddr = batadv_dat_get_dhcp_chaddr(skb, _chaddr); + if (!chaddr) + return; + + /* ARP sender MAC + IP -> DHCP Client (chaddr+yiaddr), + * ARP target MAC + IP -> DHCP Server (ethhdr/iphdr sources) + */ + if (!batadv_dat_put_pairs(bat_priv, chaddr, get_unaligned(yiaddr), + eth_hdr(skb)->h_source, ip_hdr(skb)->saddr, + vid)) + return; + + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from DHCPACK (server-side): %pI4, %pM (vid: %i)\n", + &ip_hdr(skb)->saddr, eth_hdr(skb)->h_source, + batadv_print_vid(vid)); + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped from DHCPACK (client-side): %pI4, %pM (vid: %i)\n", + yiaddr, chaddr, batadv_print_vid(vid)); +} + +/** * batadv_dat_drop_broadcast_packet() - check if an ARP request has to be * dropped (because the node has already obtained the reply via DAT) or not * @bat_priv: the bat priv with all the soft interface information diff --git a/net/batman-adv/distributed-arp-table.h b/net/batman-adv/distributed-arp-table.h index a0459602..cf58d230 100644 --- a/net/batman-adv/distributed-arp-table.h +++ b/net/batman-adv/distributed-arp-table.h @@ -46,6 +46,10 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, struct sk_buff *skb); bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, struct sk_buff *skb, int hdr_size); +void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, + struct sk_buff *skb, + __be16 proto, + unsigned short vid); bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, struct batadv_forw_packet *forw_packet); @@ -140,6 +144,13 @@ batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, return false; } +static inline void +batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, + struct sk_buff *skb, __be16 proto, + unsigned short vid) +{ +} + static inline bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, struct batadv_forw_packet *forw_packet) diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 1485263a..a8559629 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -212,6 +212,7 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, enum batadv_forw_mode forw_mode; struct batadv_orig_node *mcast_single_orig = NULL; int network_offset = ETH_HLEN; + __be16 proto; if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; @@ -223,12 +224,15 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, vid = batadv_get_vid(skb, 0); ethhdr = eth_hdr(skb); - switch (ntohs(ethhdr->h_proto)) { + proto = ethhdr->h_proto; + + switch (ntohs(proto)) { case ETH_P_8021Q: vhdr = vlan_eth_hdr(skb); + proto = vhdr->h_vlan_encapsulated_proto; /* drop batman-in-batman packets to prevent loops */ - if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN)) { + if (proto != htons(ETH_P_BATMAN)) { network_offset += VLAN_HLEN; break; } @@ -256,6 +260,9 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, goto dropped; } + /* Snoop address candidates from DHCPACKs for early DAT filling */ + batadv_dat_snoop_outgoing_dhcp_ack(bat_priv, skb, proto, vid); + /* don't accept stp packets. STP does not help in meshes. * better use the bridge loop avoidance ... * -- 2.11.0

3 2

[B.A.T.M.A.N.] [PATCH 0/5] batman-adv: Missing list checks for *list_add*
by Sven Eckelmann 06 Sep '18

06 Sep '18

Hi, over two years ago, I've added some tickets [1,2,3,4,5,6,7] about missing/not properly locked list checks for functions which create new list entries. Only Linus created a patch [8] and the other tickets were ignored. I have therefore now created the minimal version of the patches. Kind regards, Sven [1] https://www.open-mesh.org/issues/235 [2] https://www.open-mesh.org/issues/236 [3] https://www.open-mesh.org/issues/237 [4] https://www.open-mesh.org/issues/238 [5] https://www.open-mesh.org/issues/239 [6] https://www.open-mesh.org/issues/240 [7] https://www.open-mesh.org/issues/241 [8] https://patchwork.open-mesh.org/patch/4919/ Sven Eckelmann (5): batman-adv: Prevent duplicated gateway_node entry batman-adv: Prevent duplicated nc_node entry batman-adv: Prevent duplicated softif_vlan entry batman-adv: Prevent duplicated global TT entry batman-adv: Prevent duplicated tvlv handler net/batman-adv/gateway_client.c | 8 ++++++-- net/batman-adv/network-coding.c | 27 +++++++++++++++------------ net/batman-adv/soft-interface.c | 21 ++++++++++++--------- net/batman-adv/translation-table.c | 6 ++++-- net/batman-adv/tvlv.c | 8 ++++++-- 5 files changed, 43 insertions(+), 27 deletions(-) -- 2.18.0

2 10

Re: [B.A.T.M.A.N.] mcast_rate setting of wifi interface has significant effect to performance of V. Re:Re: Recent test result. Re:Re: Paper "Performance Evaluation of BATMAN-adv Wireless Mesh Network Routing Algorithms "
by Sven Eckelmann 05 Sep '18

05 Sep '18

On Dienstag, 4. September 2018 17:07:34 CEST Ligang LIU wrote: [...] > I captured frames with tcpdump and found somethings. [..] > The pcap files are attached in this email. > I'm not sure whether it's proper to send them to the mailinglist, > so I don't cc this email to the mailinglist. The mails would have been held back and I might not have accepted them due to the size of the attachments. So you did everything right. I have now added the mailing list again to the Cc > First, there are many ELP unicast packets. > > Second, there are many RTS/CTS/ACK. > When a node wants to send ELP unicast packets to a weak neighbor, this will happen frequently. > While in batman-adv 4, there is only a very small amount of RTS/CTS frames. Ack > Third, change elp interval from 500 to 1000 will decrease ELP unicast packets > but it does not decrease RTS/CTS too much. Shouldn't the number of probes be reduced and thus also the RTS? It is something which the wifi layer handles - not batman-adv. And the duration of the RTS frames seem to be rather high (I don't say that these are wrong) when I've looked through the dump via (wlan.fc.type_subtype == 0x001b) || ((llc.type == 0x4305) && (data.data[0] == 03)) Maybe someone can check whether they make sense or not (don't have the time right now to do it). > Although Antonio explained in the previous email, > "... if you have no data over the link, sending 2 probes of > 200bytes each every 500ms (default ELP interval) won't really eat much > airtime, unless you have a lot of idling 1-hop neighbours", > I think the ELP probe packets will occupy much wifi airtime, > because wlan is working on the SHARED media. > The transmission of ELP probe packets between idle 1-hop neighbours > can be heard by the other nodes and their transmission have to be delayed. > Consequently, the performance, delay and throughput, could be lowered down, > compared to batman-adv 4. @Antonio, you must also keep in mind that the RTS + CTS frames are transmitted at the lowest available rate (1Mbit/s in this case). The Ack is done with 6Mbit/s in his dump. The broadcast is done with 18Mbit/s. The unicast stuff seems to be send with MCS rates. The RTS+CTS will therefore use an amazing high number of airtime (but I didn't do the calculations). Attached are some estimates using Dave Taht's airtime- pie-chart fork [1] + a modification to show the transmitter and not the destination host. And these numbers are the raw ones - not normalized in any way (so not directly comparable). Don't forget that these also don't take the duration field of the RTS into account. [...] > And, my wireshrk (windows, v2.6.3) can not analize the batman-adv 5 packet. > I find a wireshark code for batman-adv: > https://github.com/wireshark/wireshark/blob/master/epan/dissectors/packet-b… > Is it for batman-adv 4 only? > Do you know any plugin to do this? It only support B.A.T.M.A.N. IV frames of different version. Feel free to submit the ELP and OGM2 support to wireshark (this is not necessarily directed to Ligang but to everyone). Kind regards, Sven [1] https://github.com/dtaht/airtime-pie-chart

1 1

[B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: Fix segfault when writing to throughput_override
by Sven Eckelmann 05 Sep '18

05 Sep '18

The per hardif sysfs file "batman_adv/throughput_override" prints the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: c513176e4b7a ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index f2eef43b..3a76e897 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1090,8 +1090,9 @@ static ssize_t batadv_store_throughput_override(struct kobject *kobj, if (old_tp_override == tp_override) goto out; - batadv_info(net_dev, "%s: Changing from: %u.%u MBit to: %u.%u MBit\n", - "throughput_override", + batadv_info(hard_iface->soft_iface, + "%s: %s: Changing from: %u.%u MBit to: %u.%u MBit\n", + "throughput_override", net_dev->name, old_tp_override / 10, old_tp_override % 10, tp_override / 10, tp_override % 10); -- 2.18.0

2 5

[B.A.T.M.A.N.] [PATCH maint] batman-adv: Avoid probe ELP information leak
by Sven Eckelmann 05 Sep '18

05 Sep '18

The probe ELPs for WiFi interfaces are expanded to contain at least BATADV_ELP_MIN_PROBE_SIZE bytes. This is usually a lot more than the number of bytes which the template ELP packet requires. These extra padding bytes were not initialized and thus could contain data which were previously stored at the same location. It is therefore required to set it to some predefined or random values to avoid leaking private information from the system transmitting these kind of packets. Fixes: bedcadfaa92b ("batman-adv: ELP - send unicast ELP packets for throughput sampling") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/bat_v_elp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 71c20c1d..e103c759 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -241,7 +241,7 @@ batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh) * the packet to be exactly of that size to make the link * throughput estimation effective. */ - skb_put(skb, probe_len - hard_iface->bat_v.elp_skb->len); + skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len); batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "Sending unicast (probe) ELP packet on interface %s to %pM\n", -- 2.18.0

2 3

[B.A.T.M.A.N.] fq_codel deployment
by Dave Taht 04 Sep '18

04 Sep '18

I am curious as to how better/differently/worse your networks are working now that fq-codel has been "out there" for wifi for a while. In particular I've been trying to get a "drops/day" stat vs total bytes sent from a variety of sources. -- Dave Täht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619

1 0

Re: [B.A.T.M.A.N.] Paper "Performance Evaluation of BATMAN-adv Wireless Mesh Network Routing Algorithms "
by Sven Eckelmann 03 Sep '18

03 Sep '18

On Montag, 13. August 2018 04:24:08 CEST ligang.liu(a)mail.sim.ac.cn wrote: [...] > I'm so sorry for late reply, because I was in vocation last week. No problem. But please change your reply style [2]. It is not very helpful when I first have to open my old mail to find out what you've added to the text and what was my original text :) > Thank you very much for your concern on our work. > > First of all, I have to say that the batman-adv V has performed very good in our recent tests. > The main reason why it performed poor when we tested it is the cfg80211 bug. > When we made the test in Jan. we did not know about the cfg80211 uninitialization bug. > We never thought of this kind of bug at that time, which is far beyond our scope. Thanks for checking that. In the light of this and the other problems mentioned in my mail, it would be a good idea to retract the paper with the wrong information and revisit the topic with a new paper. I would be really interested in your results and the overhead comparison - but when comparing the different B.A.T.M.A.N. algorithm versions instead of bugs in other components. This paper now could cause problems when other research use it as base for their own research - not noticing that this paper is flawed. @kekegai@smart-com.org: Are you handling the retraction of CSCloud/EdgeCom 2018 conference papers [1]? > I noticed this problem in the mail-list until in June. > > Recently, I tried to fix the bug by modified the cfg80211 source code, ref https://patchwork.kernel.org/patch/10449857/ [...] > Some tests have revealed that V has very good performance, at least not bad than IV. > We will report our results after more careful tests. Thanks > Here is my response of your questions. > > ************************************************************************************** > * What is OpenWrt 1703? (you've referenced a batman-adv config tutorial here > and there is no such version as OpenWrt 1703) > > ANS: > The base OpenWrt we used was built near in Sep. 2017, with > git clone https://git.lede-project.org/source.git > > I think the OpenWrt version should be LEDE 17.01.03 No, this would *not* result in LEDE 17.01.3 (released in Oct 3, 2017) - because you would have to specify the correct branch branch (actually the correct tag). The work on the stable versions v17.01.x was separated from the rest of the development with the branch created on on 2017-01-16. And your commands will neither use the separate branch or the actual commit - it will just use whatever master is at that time. Rather bad when somebody wants to understand how to reproduce the results of your experiment. Please make sure in your revisited paper that you make correct statements about the used software (LEDE vs. OpenWrt, git tags or actual git version's, applied patches, used feed versions, ...). Btw. there was just an actual OpenWrt release (after v15.05.1): 18.06.0 [3]. And also make sure that you're references are actually about the software. Right now your paper makes wrong statements about that kind of stuff. * don't call it OpenWRT when it is LEDE * don't name it 1703 when there is no such version and you've actually used the development branch * don't add a reference for OpenWRT 1703 which is then pointing to an unrelated config tutorial on open-mesh.org Having these incorrect statements in your paper doesn't make it look like it is of high quality. And this also causes problems when other try to use your paper as base for their own research. > ************************************************************************************** > * When did you want to contact the authors of the B.A.T.M.A.N. V > implementation in batman-adv about your findings? > > ANS: > I have tried to contact the community by sending a email to the mail-list, > with a title "What's the exact definition of expected_throughput in BATMAN-ADV V?". > In that email, I described my concern that the value of the expected_throughput was confused, > and asked for help. > > Unfortunately there are no response from there. There was no such mail on the mailing list [4]. Please make sure that you followed our requirements for this list [5] (no HTML mails). And please use shorter, more concrete subjects than that. But it seems that you never contacted the batman-adv developers via the mailing list about the other problems. > ************************************************************************************** > * How did you solve the cfg80211 bug which returns uninitialized (random) > data when asked for the expected throughput of a station? Maybe you remember > that the expected throughput is *the value* which B.A.T.M.A.N. V needs to > calculate routes. > > ANS: > Our test was done in Jan. 2018 and the paper was submitted in Feb. 2018. > At that time, I even had not realized that the problem of expected_throughput > was from cfg80211 bug. So your paper therefore (without you noticing) doesn't compare B.A.T.M.A.N. IV vs. B.A.T.M.A.N. V but still tries to establish the narrative that B.A.T.M.A.N. V is worse. > ************************************************************************************** > * What batman-adv version was used? > > ANS: > I think the version of batman-adv is 2017.3 > because the source file in OpenWrt named as: > batman-adv-2017.3 > batctl-2017.3 This already shows that you did not use LEDE 17.01.3 - because this version did never include that particular batman-adv release. You were more likely on some random LEDE development branch commit. > > ************************************************************************************** > * Did you use the openwrt-routing feed (which exact version) for > batctl+batman-adv or how did you build it? > > ANS: > Here are the main scripts. > git clone https://git.lede-project.org/source.git > ./scripts/feeds update -a > ./scripts/feeds install -a > > make download V=s > make V=99 > > At last I flushed the generated 2 files: > lede-ar71xx-generic-uImage-lzma.bin > lede-ar71xx-generic-root.squashfs These instruction will result in different version depending on when you run them. Neither the used LEDE commit is specified here nor the used feed commit. > ************************************************************************************** > * Did you generate graphs for the chosen best next hop and how it changes > over time in comparison to B.A.T.M.A.N. IV? > > ANS: > I had checked the route by batctl ping -R xxx.xxx.xxx.xxx > Unfortunately, we did not record and compare the route between IV and V. I am currently assuming that the chosen routes were wrong because of the cfg80211 bug [6]. Your brief tests with the fixed cfg80211 seem to suggest this but no way to check this now. Kind regards, Sven > [1] https://ieeexplore.ieee.org/document/8421863/ [2] https://en.wikipedia.org/wiki/Posting_style#Interleaved_style [3] https://github.com/openwrt/openwrt/releases/tag/v18.06.0 [4] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/ [5] https://www.open-mesh.org/projects/open-mesh/wiki/MailingList [6] https://patchwork.kernel.org/patch/10449857/

4 12

[B.A.T.M.A.N.] [PATCH v2 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available
by Marek Lindner 29 Aug '18

29 Aug '18

Under normal circumstances B.A.T.M.A.N. V retrieves the neighbor throughput values to populate its metric tables from the various drivers such as WiFi throughput tables and Ethernet throughput.. Whenever the interface drivers do not export link throughput information manual overrides become necessary. To further automate and thus better support these setups, ELP may call the batman-adv throughput meter to schedule a throughput estimation to be used to populate the metric table. v2: * added sysfs attribute to configure tp meter test duration * fixed null pointer dereference in TP meter packet sending routine * fixed storing the measured throughput in the correct variable * checkpatch/kerneldoc/sparse/smatch cleanup Antonio Quartulli (3): batman-adv: tp_meter - prevent concurrent tp_meter sessions by using workqueue batman-adv: tp_meter - don't check for existing session batman-adv: tp_meter - add option to perform one-hop test Marek Lindner (4): batman-adv: tp_meter - allow up to 10 queued sessions batman-adv: tp_meter - add caller distinction batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available batman-adv: ELP - add throughput meter test duration attribute .../ABI/testing/sysfs-class-net-batman-adv | 7 + include/uapi/linux/batadv_packet.h | 2 + net/batman-adv/bat_v.c | 1 + net/batman-adv/bat_v_elp.c | 66 ++- net/batman-adv/bat_v_elp.h | 21 + net/batman-adv/main.c | 10 +- net/batman-adv/main.h | 7 +- net/batman-adv/netlink.c | 3 +- net/batman-adv/routing.c | 6 +- net/batman-adv/sysfs.c | 3 + net/batman-adv/tp_meter.c | 463 +++++++++++------- net/batman-adv/tp_meter.h | 11 +- net/batman-adv/types.h | 36 ++ 13 files changed, 438 insertions(+), 198 deletions(-) -- 2.17.0

4 26

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

B.A.T.M.A.N