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

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[B.A.T.M.A.N.] [PATCH maint v2] batman-adv: fix packet loss for broadcasted DHCP packets to a server
by Linus Lüssing 24 Mar '18

24 Mar '18

DHCP connectivity issues can currently occur if the following conditions are met: 1) A DHCP packet from a client to a server 2) This packet has a multicast destination 3) This destination has a matching entry in the translation table (FF:FF:FF:FF:FF:FF for IPv4, 33:33:00:01:00:02/33:33:00:01:00:03 for IPv6) 4) The orig-node determined by TT for the multicast destination does not match the orig-node determined by best-gateway-selection In this case the DHCP packet will be dropped. The "gateway-out-of-range" check is supposed to only be applied to unicasted DHCP packets to a specific DHCP server. In that case dropping the the unicasted frame forces the client to retry via a broadcasted one, but now directed to the new best gateway. A DHCP packet with broadcast/multicast destination is already ensured to always be delivered to the best gateway. Dropping a multicasted DHCP packet here will only prevent completing DHCP as there is no other fallback. So far, it seems the unicast check was implicitly performed by expecting the batadv_transtable_search() to return NULL for multicast destinations. However, a multicast address could have always ended up in the translation table and in fact is now common. To fix this potential loss of a DHCP client-to-server packet to a multicast address this patch adds an explicit multicast destination check to reliably bail out of the gateway-out-of-range check for such destinations. The issue and fix were tested in the following three node setup: - Line topology, A-B-C - A: gateway client, DHCP client - B: gateway server, hop-penalty increased: 30->60, DHCP server - C: gateway server, code modifications to announce FF:FF:FF:FF:FF:FF Without this patch, A would never transmit its DHCP Discover packet due to an always "out-of-range" condition. With this patch, a full DHCP handshake between A and B was possible again. Fixes: afae4e42aae6 ("batman-adv: refactoring gateway handling code") Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Changes since v1: - now really fixing orig_dst_node initialization Changes since RFC: - fixed an uninitialized variable error for orig_dst_node by initializing it to NULL - Verified the issue and tested the fix in VMs, added the test setup description to the commit message --- net/batman-adv/gateway_client.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index c294f6fd..8b198ee7 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -746,7 +746,7 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, { struct batadv_neigh_node *neigh_curr = NULL; struct batadv_neigh_node *neigh_old = NULL; - struct batadv_orig_node *orig_dst_node; + struct batadv_orig_node *orig_dst_node = NULL; struct batadv_gw_node *gw_node = NULL; struct batadv_gw_node *curr_gw = NULL; struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo; @@ -757,6 +757,9 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, vid = batadv_get_vid(skb, 0); + if (is_multicast_ether_addr(ethhdr->h_dest)) + goto out; + orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source, ethhdr->h_dest, vid); if (!orig_dst_node) -- 2.11.0

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[B.A.T.M.A.N.] [PATCH maint] batman-adv: fix multicast-via-unicast transmission with AP isolation
by Linus Lüssing 24 Mar '18

24 Mar '18

For multicast frames AP isolation is only supposed to be checked on the receiving nodes and never on the originating one. Furthermore, the isolation or wifi flag bits should only be intepreted as such for unicast and never multicast TT entries. By injecting flags to the multicast TT entry claimed by a single target node it was verified in tests that this multicast address becomes unreachable, leading to packet loss. Omitting the "src" parameter to the batadv_transtable_search() call successfully skipped the AP isolation check and made the target reachable again. Fixes: 405cc1e5a81e ("batman-adv: Modified forwarding behaviour for multicast packets") Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- This issue currently cannot appear in the wild. See explanation here: https://www.open-mesh.org/issues/335#note-16 However if we were to legitimately start using these flags for multicast's own purposes then we would start to see issues in AP isolation setups. Therefore, and because the fix is tiny and "obvious", I think it would still make sense to send it through stable@. --- net/batman-adv/multicast.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index de3a055f..a11d3d89 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -869,8 +869,8 @@ static struct batadv_orig_node * batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv, struct ethhdr *ethhdr) { - return batadv_transtable_search(bat_priv, ethhdr->h_source, - ethhdr->h_dest, BATADV_NO_FLAGS); + return batadv_transtable_search(bat_priv, NULL, ethhdr->h_dest, + BATADV_NO_FLAGS); } /** -- 2.11.0

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[B.A.T.M.A.N.] [PATCH 0/3] pull request for net-next: batman-adv 2018-03-19
by Simon Wunderlich 22 Mar '18

22 Mar '18

Hi David, here is another late feature/cleanup pull request of batman-adv to go into net-next. Please pull or let me know of any problem! Thank you, Simon The following changes since commit a163dc22d515d17844435c8217ff66193d35b3fa: batman-adv: always assume 2-byte packet alignment (2018-02-27 13:02:54 +0100) are available in the git repository at: git://git.open-mesh.org/linux-merge.git tags/batadv-next-for-davem-20180319 for you to fetch changes up to 53dd9a68ba683986ec90497586f94b941bb748a0: batman-adv: add multicast flags netlink support (2018-03-14 10:15:34 +0100) ---------------------------------------------------------------- This feature/cleanup patchset includes the following patches: - avoid redundant multicast TT entries, by Linus Luessing - add netlink support for distributed arp table cache and multicast flags, by Linus Luessing (2 patches) ---------------------------------------------------------------- Linus Lüssing (3): batman-adv: Avoid redundant multicast TT entries batman-adv: add DAT cache netlink support batman-adv: add multicast flags netlink support include/uapi/linux/batman_adv.h | 82 +++++++++ net/batman-adv/distributed-arp-table.c | 152 +++++++++++++++++ net/batman-adv/distributed-arp-table.h | 8 + net/batman-adv/multicast.c | 293 ++++++++++++++++++++++++++++++++- net/batman-adv/multicast.h | 18 ++ net/batman-adv/netlink.c | 88 ++++++---- 6 files changed, 604 insertions(+), 37 deletions(-)

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[B.A.T.M.A.N.] [PATCH 0/5] pull request for net: batman-adv 2018-03-19
by Simon Wunderlich 22 Mar '18

22 Mar '18

Hi David, here are some more bugfixes for net. Please pull or let me know of any problem! Thank you, Simon The following changes since commit f22e08932c2960f29b5e828e745c9f3fb7c1bb86: batman-adv: Fix internal interface indices types (2018-02-25 20:19:34 +0100) are available in the git repository at: git://git.open-mesh.org/linux-merge.git tags/batadv-net-for-davem-20180319 for you to fetch changes up to fc04fdb2c8a894283259f5621d31d75610701091: batman-adv: Fix skbuff rcsum on packet reroute (2018-03-18 13:20:32 +0100) ---------------------------------------------------------------- Here are some batman-adv bugfixes: - fix possible IPv6 packet loss when multicast extension is used, by Linus Luessing - fix SKB handling issues for TTVN and DAT, by Matthias Schiffer (two patches) - fix include for eventpoll, by Sven Eckelmann - fix skb checksum for ttvn reroutes, by Sven Eckelmann ---------------------------------------------------------------- Linus Lüssing (1): batman-adv: Fix multicast packet loss with a single WANT_ALL_IPV4/6 flag Matthias Schiffer (2): batman-adv: update data pointers after skb_cow() batman-adv: fix header size check in batadv_dbg_arp() Sven Eckelmann (2): batman-adv: Add missing include for EPOLL* constants batman-adv: Fix skbuff rcsum on packet reroute net/batman-adv/distributed-arp-table.c | 2 +- net/batman-adv/icmp_socket.c | 1 + net/batman-adv/log.c | 1 + net/batman-adv/multicast.c | 4 ++-- net/batman-adv/routing.c | 25 +++++++++++++++---------- 5 files changed, 20 insertions(+), 13 deletions(-)

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[B.A.T.M.A.N.] [PATCH maint] batman-adv: fix packet loss for broadcasted DHCP packets to a server
by Linus Lüssing 21 Mar '18

21 Mar '18

DHCP connectivity issues can currently occur if the following conditions are met: 1) A DHCP packet from a client to a server 2) This packet has a multicast destination 3) This destination has a matching entry in the translation table (FF:FF:FF:FF:FF:FF for IPv4, 33:33:00:01:00:02/33:33:00:01:00:03 for IPv6) 4) The orig-node determined by TT for the multicast destination does not match the orig-node determined by best-gateway-selection In this case the DHCP packet will be dropped. The "gateway-out-of-range" check is supposed to only be applied to unicasted DHCP packets to a specific DHCP server. In that case dropping the the unicasted frame forces the client to retry via a broadcasted one, but now directed to the new best gateway. A DHCP packet with broadcast/multicast destination is already ensured to always be delivered to the best gateway. Dropping a multicasted DHCP packet here will only prevent completing DHCP as there is no other fallback. So far, it seems the unicast check was implicitly performed by expecting the batadv_transtable_search() to return NULL for multicast destinations. However, a multicast address could have always ended up in the translation table and in fact is now common. To fix this potential loss of a DHCP client-to-server packet to a multicast address this patch adds an explicit multicast destination check to reliably bail out of the gateway-out-of-range check for such destinations. The issue and fix were tested in the following three node setup: - Line topology, A-B-C - A: gateway client, DHCP client - B: gateway server, hop-penalty increased: 30->60, DHCP server - C: gateway server, code modifications to announce FF:FF:FF:FF:FF:FF Without this patch, A would never transmit its DHCP Discover packet due to an always "out-of-range" condition. With this patch, a full DHCP handshake between A and B was possible again. Fixes: afae4e42aae6 ("batman-adv: refactoring gateway handling code") Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Changes since RFC: - fixed an uninitialized variable error for orig_dst_node by initializing it to NULL - Verified the issue and tested the fix in VMs, added the test setup description to the commit message --- net/batman-adv/gateway_client.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index c294f6fd..e7a245bd 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -757,6 +757,9 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv, vid = batadv_get_vid(skb, 0); + if (is_multicast_ether_addr(ethhdr->h_dest)) + goto out; + orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source, ethhdr->h_dest, vid); if (!orig_dst_node) -- 2.11.0

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[B.A.T.M.A.N.] [PATCH] batctl: netlink: fix resetting mcast_flags_priv to unsupported state
by Linus Lüssing 20 Mar '18

20 Mar '18

This fixes a copy & paste error detected by Coverity. Fixes: b56061058113 ("batctl: add netlink dump function for multicast flags table") Reported-by: scan-admin(a)coverity.com Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/netlink.c b/netlink.c index ab7be1e..f0fd1d9 100644 --- a/netlink.c +++ b/netlink.c @@ -252,7 +252,7 @@ static int info_callback(struct nl_msg *msg, void *arg) if (attrs[BATADV_ATTR_MCAST_FLAGS_PRIV]) mcast_flags_priv = nla_get_u32(attrs[BATADV_ATTR_MCAST_FLAGS_PRIV]); else - mcast_flags = -EOPNOTSUPP; + mcast_flags_priv = -EOPNOTSUPP; switch (opts->nl_cmd) { case BATADV_CMD_GET_TRANSTABLE_LOCAL: -- 2.11.0

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[B.A.T.M.A.N.] [RFC PATCH maint 1/2] batman-adv: fix packet loss for broadcasted DHCP packets to a server
by Linus Lüssing 20 Mar '18

20 Mar '18

1 1

Re: [B.A.T.M.A.N.] New Defects reported by Coverity Scan for batctl
by Linus Lüssing 20 Mar '18

20 Mar '18

On Mon, Mar 19, 2018 at 01:17:37AM +0000, scan-admin(a)coverity.com wrote: [...] > ________________________________________________________________________________________________________ > *** CID 174547: Incorrect expression (COPY_PASTE_ERROR) > /netlink.c: 255 in info_callback() > 249 else > 250 mcast_flags = -EOPNOTSUPP; > 251 > 252 if (attrs[BATADV_ATTR_MCAST_FLAGS_PRIV]) > 253 mcast_flags_priv = nla_get_u32(attrs[BATADV_ATTR_MCAST_FLAGS_PRIV]); > 254 else > >>> CID 174547: Incorrect expression (COPY_PASTE_ERROR) > >>> "mcast_flags" in "mcast_flags = -95L" looks like a copy-paste error. > 255 mcast_flags = -EOPNOTSUPP; [...] Now this is officially the second time a code/patch reviewing algorithm creeps me out :D. "Looks like", yeah... and even worse, the AI is actually right... I will send a fix :). Cheers

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[B.A.T.M.A.N.] [PATCH] batctl: Add tp debug log messages switch
by Sven Eckelmann 19 Mar '18

19 Mar '18

The switch to enable/disable throughput meter debug messages in `batctl log` is supported since batman-adv 2016.3 but was never adopted in batctl. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- README.rst | 1 + man/batctl.8 | 7 ++++--- sys.c | 7 ++++++- 3 files changed, 11 insertions(+), 4 deletions(-) diff --git a/README.rst b/README.rst index 256e153..4c0f544 100644 --- a/README.rst +++ b/README.rst @@ -428,6 +428,7 @@ Example:: [ ] messages related to arp snooping and distributed arp table (dat) [ ] messages related to network coding (nc) [ ] messages related to multicast (mcast) + [ ] messages related to throughput meter (tp) batctl nc_nodes diff --git a/man/batctl.8 b/man/batctl.8 index 7cf66ca..d5fc530 100644 --- a/man/batctl.8 +++ b/man/batctl.8 @@ -107,9 +107,10 @@ level. Level 'none' disables all verbose logging. Level 'batman' enables message Level 'routes' enables messages related to routes being added / changed / deleted. Level 'tt' enables messages related to translation table operations. Level 'bla' enables messages related to the bridge loop avoidance. Level 'dat' enables messages related to ARP snooping and the Distributed Arp Table. Level 'nc' enables messages related to network coding. -Level 'mcast' enables messages related to multicast optimizations. Level 'all' enables all messages. The messages -are sent to the batman-adv debug log. Use \fBbatctl log\fP to retrieve it. Make sure to have debugging output enabled -when compiling the module otherwise the output as well as the loglevel options won't be available. +Level 'mcast' enables messages related to multicast optimizations. Level 'tp' enables messages related to throughput meter. +Level 'all' enables all messages. The messages are sent to the batman-adv debug log. Use \fBbatctl log\fP to retrieve it. +Make sure to have debugging output enabled when compiling the module otherwise the output as well as the loglevel options +won't be available. .br .IP "\fBlog\fP|\fBl\fP [\fB\-n\fP]\fP" batctl will read the batman-adv debug log which has to be compiled into the kernel module. If "\-n" is given batctl will not diff --git a/sys.c b/sys.c index 068aa31..e0c2073 100644 --- a/sys.c +++ b/sys.c @@ -132,6 +132,7 @@ static void log_level_usage(void) fprintf(stderr, " \t dat Messages related to arp snooping and distributed arp table\n"); fprintf(stderr, " \t nc Messages related to network coding\n"); fprintf(stderr, " \t mcast Messages related to multicast\n"); + fprintf(stderr, " \t tp Messages related to throughput meter\n"); } int handle_loglevel(char *mesh_iface, int argc, char **argv) @@ -169,7 +170,7 @@ int handle_loglevel(char *mesh_iface, int argc, char **argv) log_level = 0; break; } else if (strcmp(argv[i], "all") == 0) { - log_level = 127; + log_level = 255; break; } else if (strcmp(argv[i], "batman") == 0) log_level |= BIT(0); @@ -185,6 +186,8 @@ int handle_loglevel(char *mesh_iface, int argc, char **argv) log_level |= BIT(5); else if (strcmp(argv[i], "mcast") == 0) log_level |= BIT(6); + else if (strcmp(argv[i], "tp") == 0) + log_level |= BIT(7); else { log_level_usage(); goto out; @@ -220,6 +223,8 @@ int handle_loglevel(char *mesh_iface, int argc, char **argv) "messages related to network coding", "nc"); printf("[%c] %s (%s)\n", (log_level & BIT(6)) ? 'x' : ' ', "messages related to multicast", "mcast"); + printf("[%c] %s (%s)\n", (log_level & BIT(7)) ? 'x' : ' ', + "messages related to throughput meter", "tp"); out: free(path_buff); -- 2.16.2

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[B.A.T.M.A.N.] [PATCH maint] batctl: Enable mcast log level with "all"
by Sven Eckelmann 19 Mar '18

19 Mar '18

The BIT(6) has to be set when the "all" loglevel is used to really get all the log output which is known to batctl. Fixes: 55042b3a3bbf ("batctl: adding multicast debug level") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- sys.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys.c b/sys.c index bf77b7d..068aa31 100644 --- a/sys.c +++ b/sys.c @@ -169,7 +169,7 @@ int handle_loglevel(char *mesh_iface, int argc, char **argv) log_level = 0; break; } else if (strcmp(argv[i], "all") == 0) { - log_level = 63; + log_level = 127; break; } else if (strcmp(argv[i], "batman") == 0) log_level |= BIT(0); -- 2.16.2

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