B.A.T.M.A.N March 2018

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

12 participants
41 discussions

[B.A.T.M.A.N.] [PATCH] batman-adv: Fix skbuff rcsum on packet reroute

by Sven Eckelmann

batadv_check_unicast_ttvn may redirect a packet to itself or another originator. This involves rewriting the ttvn and the destination address in the batadv unicast header. These field were not yet pulled (with skb rcsum update) and thus any change to them also requires a change in the receive checksum. Reported-by: Matthias Schiffer <mschiffer(a)universe-factory.net> Fixes: cea194d90b11 ("batman-adv: improved client announcement mechanism") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- Cc: Matthias Schiffer <mschiffer(a)universe-factory.net> This is an alternative fix for the problem reported by Matthias and his patch https://patchwork.open-mesh.org/patch/17305/. I've prepared it because I don't feel good about fixing one thing and at the same time add regression to another thing (even when it is only the debug output for arp packets) - at least not when this patch should end up at stable(a)vger.kernel.org This patch was not actually tested. But it should help to see a different approach. Other code in the kernel which does something similar is: * seg6_do_srh_inline * set_eth_addr (openvswitch) * set_nsh (openvswitch) I would still like to merge the cleanup patches from Matthias - just not for net.git/stable(a)vger.kernel.org. Maybe Simon can decide about the maint patch - at least he will be the one who forwards them to DaveM. Btw. in theory, only ttl+ttvn+dest have to be read to update the checksum correctly - but this patch also reads packet_type+version to keep the change simple. --- compat-include/linux/skbuff.h | 12 ++++++++++++ compat-sources/net/core/skbuff.c | 17 ----------------- net/batman-adv/routing.c | 15 ++++++++++----- 3 files changed, 22 insertions(+), 22 deletions(-) diff --git a/compat-include/linux/skbuff.h b/compat-include/linux/skbuff.h index 1983dbeb..6f739464 100644 --- a/compat-include/linux/skbuff.h +++ b/compat-include/linux/skbuff.h @@ -77,6 +77,18 @@ struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, #endif /* < KERNEL_VERSION(4, 2, 0) */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0) + +static inline void skb_postpush_rcsum(struct sk_buff *skb, + const void *start, unsigned int len) +{ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_block_add(skb->csum, + csum_partial(start, len, 0), 0); +} + +#endif /* < KERNEL_VERSION(4, 5, 0) */ + #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0) static inline void *batadv_skb_put(struct sk_buff *skb, unsigned int len) diff --git a/compat-sources/net/core/skbuff.c b/compat-sources/net/core/skbuff.c index 3827f5c7..30fbfbfb 100644 --- a/compat-sources/net/core/skbuff.c +++ b/compat-sources/net/core/skbuff.c @@ -93,23 +93,6 @@ skb_checksum_validate(struct sk_buff *skb, int proto, #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0) -static inline void skb_postpush_rcsum(struct sk_buff *skb, - const void *start, unsigned int len) -{ - /* For performing the reverse operation to skb_postpull_rcsum(), - * we can instead of ... - * - * skb->csum = csum_add(skb->csum, csum_partial(start, len, 0)); - * - * ... just use this equivalent version here to save a few - * instructions. Feeding csum of 0 in csum_partial() and later - * on adding skb->csum is equivalent to feed skb->csum in the - * first place. - */ - if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->csum = csum_partial(start, len, skb->csum); -} - /** * skb_push_rcsum - push skb and update receive checksum * @skb: buffer to update diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 0f10c565..cc3ed93a 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -759,6 +759,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb, /** * batadv_reroute_unicast_packet() - update the unicast header for re-routing * @bat_priv: the bat priv with all the soft interface information + * @skb: unicast packet to process * @unicast_packet: the unicast header to be updated * @dst_addr: the payload destination * @vid: VLAN identifier @@ -770,7 +771,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb, * Return: true if the packet header has been updated, false otherwise */ static bool -batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, +batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_unicast_packet *unicast_packet, u8 *dst_addr, unsigned short vid) { @@ -799,8 +800,10 @@ batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, } /* update the packet header */ + skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, orig_addr); unicast_packet->ttvn = orig_ttvn; + skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ret = true; out: @@ -841,7 +844,7 @@ static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, * the packet to */ if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) { - if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, @@ -887,7 +890,7 @@ static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, * destination can possibly be updated and forwarded towards the new * target host */ - if (batadv_reroute_unicast_packet(bat_priv, unicast_packet, + if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) { batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", @@ -910,12 +913,14 @@ static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, if (!primary_if) return false; + /* update the packet header */ + skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr); + unicast_packet->ttvn = curr_ttvn; + skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); batadv_hardif_put(primary_if); - unicast_packet->ttvn = curr_ttvn; - return true; } -- 2.16.2

5 years

[B.A.T.M.A.N.] [PATCH maint 1/3] batman-adv: update data pointers after skb_cow()

by Matthias Schiffer

batadv_check_unicast_ttvn() calls skb_cow(), so pointers into the SKB data must be (re)set after calling it. The ethhdr variable is dropped altogether. Signed-off-by: Matthias Schiffer <mschiffer(a)universe-factory.net> --- net/batman-adv/routing.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 289df027ecdd..0f10c565ac85 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -968,14 +968,10 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL; int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; - struct ethhdr *ethhdr; int ret = NET_RX_DROP; bool is4addr, is_gw; unicast_packet = (struct batadv_unicast_packet *)skb->data; - unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; - ethhdr = eth_hdr(skb); - is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; /* the caller function should have already pulled 2 bytes */ if (is4addr) @@ -995,12 +991,14 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) goto free_skb; + unicast_packet = (struct batadv_unicast_packet *)skb->data; + /* packet for me */ if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { /* If this is a unicast packet from another backgone gw, * drop it. */ - orig_addr_gw = ethhdr->h_source; + orig_addr_gw = eth_hdr(skb)->h_source; orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw); if (orig_node_gw) { is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw, @@ -1015,6 +1013,8 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, } if (is4addr) { + unicast_4addr_packet = + (struct batadv_unicast_4addr_packet *)skb->data; subtype = unicast_4addr_packet->subtype; batadv_dat_inc_counter(bat_priv, subtype); -- 2.16.2

5 years

[B.A.T.M.A.N.] [PATCH v3 0/4] batctl: netlink support for DAT and MCAST

by Linus Lüssing

This patchset adds netlink support for dumping DAT cache and multicast flags tables. Changes in v3: ============== - renamed netlink attributes: - BATADV_ATTR_DC_ADDRESS -> BATADV_ATTR_DAT_CACHE_IP4ADDRESS - BATADV_ATTR_DC_HWADDRESS -> BATADV_ATTR_DAT_CACHE_HWADDRESS - BATADV_ATTR_DC_VID -> BATADV_ATTR_DAT_CACHE_VID Changes in v2: ============== - Removed htonl() conversion for BATADV_ATTR_DC_ADDRESS as batman-adv now provides it in network byte order (via nla_put_in_addr() ) - Increased BATADV_ATTR_MCAST_FLAGS and BATADV_ATTR_MCAST_FLAGS_PRIV size from 8 to 32 bits to enhance extensibility - Changed mcast_flags error value from -EINVAL to -ENOTSUPP to allow a fallback to and retry via debugfs, for compatibility with older batman-adv versions

5 years

[B.A.T.M.A.N.] [PATCH v3 0/2] batman-adv: netlink support for DAT and MCAST

by Linus Lüssing

This patchset adds netlink support for dumping DAT cache and multicast flags tables. Changes in v3: ============== - renamed netlink attributes: - BATADV_ATTR_DC_ADDRESS -> BATADV_ATTR_DAT_CACHE_IP4ADDRESS - BATADV_ATTR_DC_HWADDRESS -> BATADV_ATTR_DAT_CACHE_HWADDRESS - BATADV_ATTR_DC_VID -> BATADV_ATTR_DAT_CACHE_VID Changes in v2: ============== - Added missing includes, "#include <linux/netlink.h>" and "#include <uapi/linux/batman_adv.h>", to distributed-arp-table.c - Added missing forward declaration for "struct netlink_callback" to distributed-arp-table.h - Changed nla_put_u32() to nla_put_in_addr() for BATADV_ATTR_DC_ADDRESS, removed the then obsolete ntohl() conversion - Added missing include, "#include <linux/netlink.h>", to multicast.c - Changed nla_put_u8() to nla_put_u32() for BATADV_ATTR_MCAST_FLAGS and BATADV_ATTR_MCAST_FLAGS_PRIV to enhance extensibility

5 years

[B.A.T.M.A.N.] [PATCH v2 0/2] batman-adv: netlink support for DAT and MCAST

by Linus Lüssing

This patchset adds netlink support for dumping DAT cache and multicast flags tables. Changes in v2: ============== - Added missing includes, "#include <linux/netlink.h>" and "#include <uapi/linux/batman_adv.h>", to distributed-arp-table.c - Added missing forward declaration for "struct netlink_callback" to distributed-arp-table.h - Changed nla_put_u32() to nla_put_in_addr() for BATADV_ATTR_DC_ADDRESS, removed the then obsolete ntohl() conversion - Added missing include, "#include <linux/netlink.h>", to multicast.c - Changed nla_put_u8() to nla_put_u32() for BATADV_ATTR_MCAST_FLAGS and BATADV_ATTR_MCAST_FLAGS_PRIV to enhance extensibility

5 years

[B.A.T.M.A.N.] Fwd: [Battlemesh] Mesh is in the air! - 7th-13th of May 2018, Berlin, Germany

by Simon Wunderlich

Let's meet in Berlin in May :) ---------- Forwarded Message ---------- Subject: [Battlemesh] Mesh is in the air! - 7th-13th of May 2018, Berlin, Germany Date: Friday, March 9, 2018, 10:13:56 PM CET From: Monic Meisel <monic(a)monic.de> To: Battle of the Mesh Mailing List <battlemesh(a)ml.ninux.org> Dear fellow Battlemesh enthusiasts, The Wireless Battle of the Mesh v11 (#WBMv11) and the Wireless Community Weekend 2018 (#FFWCW18) will be meshed up and co-located in Berlin from May 07 to May 13, 2018. Since it is the 15th anniversary of the WCW, friends and fellows from across the globe celebrate together wireless mesh network technologies and ideas of community networking. You can expect to meet with tech experts in mesh technologies, policy discussions, talks, hands on workshops, late night hacking sessions, measurement campaigns and an ongoing barbeque at the riverside. If you are a mesh networking enthusiast, community activist, or simply have an interest in wifi or dynamic routing protocols, you can't miss this event! So check out our continuously updated information about the event at https:// www.wireless-meshup.org Location ======= We are meeting at the c-base space station, 3 minutes from public transport S +U Jannowitzbrücke in the heart of Berlin. There you will find the main hall with the bar for presentations, discussions and hacking, a seminar room for up to 15 for workshops, two spaces for a smaller groups in the basement and upper floor and not at least the fully equipped riverside with powersockets, light close to the grill station. For the weekend we booked another room for presentations at European Theater Institute right next door to the seminar room. You will find yourself at Berlins most famous hackspace, where you can use repair and assembling shops as well as meeting with berlins net activists and hacker scene. freifunk.net is available, since the roof top node is part of the BerlinBackBone. Taking part and Registration ===================== It helps the organizers, if you add yourself early to the wiki page under https://www.wireless-meshup.org/ and provide your meal prefernces and t-shirt size, in case you want one. Start preparing your presentation, lightening talk, workshop, idea, announcement or open space you want to run. The event is *free of charge*, but contributions are very welcome, so please have a look at the supporters page as well, thanks in advance. Accommodation Offering =================== For those of you who are looking for a convenient accommodation option: we have made block reservation for 50 beds in a nice hostel 15 min walking distance or one station by public transport. The packages include 7 nights in a three or four-bed room incl. breakfast - for 33,00 EUR p.P/Night incl. Breakfast Valid for: 07.05.2018 - 13.05.2018 50 Beds are reserved until 23.03.2018 25 Beds are reserved until 05.04.2018 Payment at checkin - using cash or creditcard IMPORTANT: Booking with this special price is only possible by mail ap(a)meininger-hotels.com or phone +493031879767 Stating that you want to stay at “EastSideGallery” mention the Keyword: MESH Booked Rooms will be held until 6pm on arrival day - please let them know when you arrive later. Catering and Social Events ===================== There will be catering at dinner time and free coffee the whole time. Beverages can be bought at the bar, closeby kiosk or brought with you. Some jaunts and social events are in planning, but will be announced later. Spread the Word ============= Please help us spreading the word by forwarding this to all lists and people that might be interested. Blogging about it is also very appreciated, and if you do so, please add a ping-back to the wiki page: https://www.wireless-meshup.org We will also start the endorsements process within some weeks. If your community/organization would like to help and support us, please check supporters page. Organizers Team Contact ==================== The local core team consists of Monic, Andi, Cven and others from freifunk and c-base community. The mentors team consists of Claudio, Filipe and Paul. You can reach us under organizers(a)wireless-meshup.org Hope to see you soon! Best wishes from the org-team -----------------------------------------

5 years

[B.A.T.M.A.N.] [PATCH maint] batman-adv: Only provide (READ|WRITE)_ONCE when undefined

by Sven Eckelmann

The Debian Jessie 3.16.x kernels (3.16.36-1 and later) modified the the kernel sources to already provide the READ_ONCE and WRITE_ONCE kernel macros. The batman-adv compat helper defines will conflict on such kernels and thus prevent the compilation against these downstream kernels. Reported-by: Ralf Jung <post(a)ralfj.de> Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- Cc: Ralf Jung <post+openmesh(a)ralfj.de> See https://www.open-mesh.org/issues/350 --- compat-include/linux/compiler.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/compat-include/linux/compiler.h b/compat-include/linux/compiler.h index 62b6a2f9..45cd49fa 100644 --- a/compat-include/linux/compiler.h +++ b/compat-include/linux/compiler.h @@ -26,11 +26,15 @@ #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0) +#ifndef READ_ONCE #define READ_ONCE(x) ACCESS_ONCE(x) +#endif +#ifndef WRITE_ONCE #define WRITE_ONCE(x, val) ({ \ ACCESS_ONCE(x) = (val); \ }) +#endif #endif /* < KERNEL_VERSION(3, 19, 0) */ -- 2.16.1

5 years

[B.A.T.M.A.N.] [PATCH v2 0/4] batctl: netlink support for DAT and MCAST

by Linus Lüssing

This patchset adds netlink support for dumping DAT cache and multicast flags tables. Changes in v2: ============== - Removed htonl() conversion for BATADV_ATTR_DC_ADDRESS as batman-adv now provides it in network byte order (via nla_put_in_addr() ) - Increased BATADV_ATTR_MCAST_FLAGS and BATADV_ATTR_MCAST_FLAGS_PRIV size from 8 to 32 bits to enhance extensibility - Changed mcast_flags error value from -EINVAL to -ENOTSUPP to allow a fallback to and retry via debugfs, for compatibility with older batman-adv versions

5 years

[B.A.T.M.A.N.] [bug report] batman-adv: Ignore invalid batadv_v_gw during netlink send

by Dan Carpenter

Hello Sven Eckelmann, The patch 011c935fceae: "batman-adv: Ignore invalid batadv_v_gw during netlink send" from Feb 19, 2018, leads to the following static checker warning: net/batman-adv/bat_iv_ogm.c:2745 batadv_iv_gw_dump_entry() warn: missing error code here? 'batadv_neigh_ifinfo_get()' failed. 'ret' = '0' net/batman-adv/bat_iv_ogm.c 2719 /** 2720 * batadv_iv_gw_dump_entry() - Dump a gateway into a message 2721 * @msg: Netlink message to dump into 2722 * @portid: Port making netlink request 2723 * @seq: Sequence number of netlink message 2724 * @bat_priv: The bat priv with all the soft interface information 2725 * @gw_node: Gateway to be dumped 2726 * 2727 * Return: Error code, or 0 on success ^^^^^^^^^^^^^^^^^^^^^^^^^^^ This is sort of out of date. 2728 */ 2729 static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq, 2730 struct batadv_priv *bat_priv, 2731 struct batadv_gw_node *gw_node) 2732 { 2733 struct batadv_neigh_ifinfo *router_ifinfo = NULL; 2734 struct batadv_neigh_node *router; 2735 struct batadv_gw_node *curr_gw; 2736 int ret = 0; 2737 void *hdr; 2738 2739 router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT); 2740 if (!router) 2741 goto out; ^^^^^^^^ 2742 2743 router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT); 2744 if (!router_ifinfo) 2745 goto out; ^^^^^^^^ These two were obviously changed from -EINVAL to 0 intentionally, but it causes a static checker warning. What really helps me when I'm reviewing error codes is if they're explicit: if (!router_ifinfo) { ret = 0; goto out; } 2746 2747 curr_gw = batadv_gw_get_selected_gw_node(bat_priv); 2748 2749 hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, 2750 NLM_F_MULTI, BATADV_CMD_GET_GATEWAYS); 2751 if (!hdr) { 2752 ret = -ENOBUFS; ^^^^^^^^^^^^^^ The commit message sort of implies that only -EMSGSIZE and 0 are valid returns but -ENOBUFS is also valid. 2753 goto out; 2754 } 2755 2756 ret = -EMSGSIZE; ^^^^^^^^^^^^^^^ 2757 2758 if (curr_gw == gw_node) 2759 if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) { 2760 genlmsg_cancel(msg, hdr); 2761 goto out; 2762 } 2763 Anyway, the code seems fine and I've marked it as a false positive so it doesn't really require any action from you. I just wanted you to know my thinking here. regards, dan carpenter

5 years

Re: [B.A.T.M.A.N.] Questions about hardware

by Sven Eckelmann

[Please try to not contact me directly when it is about B.A.T.M.A.N. related things and at least Cc the official mailing list] On Montag, 5. März 2018 19:04:29 CET Paul Becue wrote: > We are working on a device with a mesh network. We are doing tests with > WiFi ad-hoc networks, and we tested last week BATMAN-adv and also babeld > on a Raspberry Pi 3 with a Ralink dongle attached to it. The results > were very good. [..] > Could you give me some hints where I have to look for hardware and what > kind of hardware I have to look for? I have the impression that there is > something that I don't see in the whole story. I hope ad-hoc WiFi is > still a technology that is up to date. Or is there a technology that > replaces it? Yes, IBSS is becoming a problem at the moment. You can try QCA ath10k hardware with Ben Greears firmware [1] or Mediathek with the mt76 driver [2] when you want up-to-date HW. There is still some ath9k based stuff around when 802.11n is enough. Otherwise you might try to replace IBSS with meshpoint interfaces. Just setup it like 802.11s but with forwarding disabled [3]. This works at least with ath10k based HW and the official QCA ath10k firmware. But HW which uses ath10k and other things which uses special firmware which prevents you from using your "own" rate control algorith are a no-go when you want to use throughput based metrics (as in B.A.T.M.A.N. V or olsrd2). Then you should stick either with ath9k or mt76 compatible HW. Btw. my tests of mt76 showed performance and stability problems in the past. This may have changed by recent fixes in the driver but I don't know the current state. Kind regards, Sven [1] https://www.candelatech.com/ath10k.php [2] https://github.com/openwrt/mt76 [3] http://openwrt-devel.openwrt.narkive.com/Bieu1aRR/ath10k-mesh-with-openwrt-…

5 years

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B.A.T.M.A.N March 2018