B.A.T.M.A.N April 2019

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

9 participants
21 discussions

[B.A.T.M.A.N.] [PATCH] batctl: Drop log subcommand
by Sven Eckelmann 22 Apr '19

22 Apr '19

The correct way to get a log of the activities of batman-adv is to use the standard kernel tracing infrastructure: $ trace-cmd stream -e batadv:batadv_dbg The batman-adv specific log file will be removed in the future when the debugfs is dropped. And even for kernels without tracing support, most of the functionality (except mac address to bat_hosts translation) can be replaced by a simple: $ cat /sys/kernel/debug/batman_adv/bat0/log Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- Makefile | 1 - README.rst | 22 -------------------- debug.h | 1 - functions.c | 7 ++----- functions.h | 1 - log.c | 59 ---------------------------------------------------- man/batctl.8 | 4 ---- 7 files changed, 2 insertions(+), 93 deletions(-) delete mode 100644 log.c diff --git a/Makefile b/Makefile index df8b7b9..b7bd545 100755 --- a/Makefile +++ b/Makefile @@ -52,7 +52,6 @@ $(eval $(call add_command,gw_mode,y)) $(eval $(call add_command,hop_penalty,y)) $(eval $(call add_command,interface,y)) $(eval $(call add_command,isolation_mark,y)) -$(eval $(call add_command,log,y)) $(eval $(call add_command,loglevel,y)) $(eval $(call add_command,mcast_flags,y)) $(eval $(call add_command,multicast_fanout,y)) diff --git a/README.rst b/README.rst index 03ea5e5..bc54412 100644 --- a/README.rst +++ b/README.rst @@ -386,28 +386,6 @@ Example:: 1000 -batctl log -========== - -read the log produced by the kernel module - -Usage:: - - batctl log|l - -Example:: - - $ batctl log - [ 400] Received BATMAN packet via NB: fe:fe:00:00:02:01 IF: eth0 [fe:fe:00:00:01:01] (from OG: fe:fe:00:00:01:01 via prev OG: fe:fe:00:00:01:01 seqno 670, tq 245, TTL 49, V 8, IDF 1) - [ 400] Drop packet: originator packet from myself (via neighbour) - [ 400] Received BATMAN packet via NB: fe:fe:00:00:02:01 IF: eth0 [fe:fe:00:00:01:01] (from OG: fe:fe:00:00:02:01 via prev OG: fe:fe:00:00:02:01 seqno 545, tq 255, TTL 50, V 8, IDF 0) - [ 400] updating last_seqno: old 544, new 545 - [ 400] bidirectional: orig = fe:fe:00:00:02:01 neigh = fe:fe:00:00:02:01 => own_bcast = 64, real recv = 64, local tq: 255, asym_penalty: 255, total tq: 255 - [ 400] update_originator(): Searching and updating originator entry of received packet - [ 400] Updating existing last-hop neighbour of originator - [...] - - batctl loglevel =============== diff --git a/debug.h b/debug.h index 3294361..bae33e5 100644 --- a/debug.h +++ b/debug.h @@ -19,7 +19,6 @@ #define DEBUG_DAT_CACHE "dat_cache" #define DEBUG_NC_NODES "nc_nodes" #define DEBUG_MCAST_FLAGS "mcast_flags" -#define DEBUG_LOG "log" #define DEBUG_ROUTING_ALGOS "routing_algos" struct debug_table_data { diff --git a/functions.c b/functions.c index bb7f517..636ff8d 100644 --- a/functions.c +++ b/functions.c @@ -275,11 +275,8 @@ int read_file(const char *dir, const char *fname, int read_opt, if (!bat_host) goto print_plain_buff; - if (read_opt & LOG_MODE) - printf("%s", bat_host->name); - else - /* keep table format */ - printf("%17s", bat_host->name); + /* keep table format */ + printf("%17s", bat_host->name); goto written; diff --git a/functions.h b/functions.h index 02f7823..d4a5568 100644 --- a/functions.h +++ b/functions.h @@ -69,7 +69,6 @@ enum { CONT_READ = 0x01, CLR_CONT_READ = 0x02, USE_BAT_HOSTS = 0x04, - LOG_MODE = 0x08, USE_READ_BUFF = 0x10, SILENCE_ERRORS = 0x20, NO_OLD_ORIGS = 0x40, diff --git a/log.c b/log.c deleted file mode 100644 index e950bad..0000000 --- a/log.c +++ /dev/null @@ -1,59 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* Copyright (C) 2009-2019 B.A.T.M.A.N. contributors: - * - * Marek Lindner <mareklindner(a)neomailbox.ch> - * - * License-Filename: LICENSES/preferred/GPL-2.0 - */ - -#include <getopt.h> -#include <stdio.h> -#include <stdlib.h> - -#include "debug.h" -#include "debugfs.h" -#include "functions.h" - -static void log_usage(void) -{ - fprintf(stderr, "Usage: batctl [options] log [parameters]\n"); - fprintf(stderr, "parameters:\n"); - fprintf(stderr, " \t -h print this help\n"); - fprintf(stderr, " \t -n don't replace mac addresses with bat-host names\n"); -} - -static int log_print(struct state *state, int argc, char **argv) -{ - int optchar, res, read_opt = USE_BAT_HOSTS | LOG_MODE; - char full_path[MAX_PATH+1]; - char *debugfs_mnt; - - while ((optchar = getopt(argc, argv, "hn")) != -1) { - switch (optchar) { - case 'h': - log_usage(); - return EXIT_SUCCESS; - case 'n': - read_opt &= ~USE_BAT_HOSTS; - break; - default: - log_usage(); - return EXIT_FAILURE; - } - } - - check_root_or_die("batctl log"); - - debugfs_mnt = debugfs_mount(NULL); - if (!debugfs_mnt) { - fprintf(stderr, "Error - can't mount or find debugfs\n"); - return EXIT_FAILURE; - } - - debugfs_make_path(DEBUG_BATIF_PATH_FMT "/", state->mesh_iface, full_path, sizeof(full_path)); - res = read_file(full_path, DEBUG_LOG, read_opt, 0, 0, 0); - return res; -} - -COMMAND_NAMED(SUBCOMMAND, log, "l", log_print, COMMAND_FLAG_MESH_IFACE, NULL, - " \tread the log produced by the kernel module"); diff --git a/man/batctl.8 b/man/batctl.8 index 8d7332a..0b43031 100644 --- a/man/batctl.8 +++ b/man/batctl.8 @@ -127,10 +127,6 @@ Level 'all' enables all messages. The messages are sent to the batman-adv debug 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 -replace the MAC addresses with bat\-host names in the output. -.br .IP "\fBgw_mode|gw\fP [\fBoff\fP|\fBclient\fP|\fBserver\fP] [\fBsel_class|bandwidth\fP]\fP" If no parameter is given the current gateway mode is displayed otherwise the parameter is used to set the gateway mode. The second (optional) argument specifies the selection class (if 'client' was the first argument) or the gateway bandwidth (if 'server' -- 2.20.1

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[B.A.T.M.A.N.] [PATCH] batctl: Drop support for translating destinations via debugfs
by Sven Eckelmann 22 Apr '19

22 Apr '19

The support for getting the necessary data for translating traceroute/ping destinations via netlink was added 3 years ago to batman-adv. The old debugfs functionality is also currently disabled by default and will be dropped completely in 2021. These convenience helpers are now dropped as first step to get rid of debugfs functionality in batctl. They are still provided when batman-adv provides the generic batadv netlink family. Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- functions.c | 91 +-------------------------------------------------- icmp_helper.c | 90 -------------------------------------------------- ping.c | 8 ----- traceroute.c | 8 ----- 4 files changed, 1 insertion(+), 196 deletions(-) diff --git a/functions.c b/functions.c index 636ff8d..aad6327 100644 --- a/functions.c +++ b/functions.c @@ -353,98 +353,12 @@ int write_file(const char *dir, const char *fname, const char *arg1, return res; } -static int translate_mac_debugfs(const char *mesh_iface, - const struct ether_addr *mac, - struct ether_addr *mac_out) -{ - enum { - tg_start, - tg_mac, - tg_via, - tg_originator, - } pos; - char full_path[MAX_PATH+1]; - char *debugfs_mnt; - struct ether_addr *mac_tmp; - FILE *f = NULL; - size_t len = 0; - char *line = NULL; - char *input, *saveptr, *token; - int line_invalid; - bool found = false; - - debugfs_mnt = debugfs_mount(NULL); - if (!debugfs_mnt) - return -EOPNOTSUPP; - - debugfs_make_path(DEBUG_BATIF_PATH_FMT "/" DEBUG_TRANSTABLE_GLOBAL, mesh_iface, full_path, sizeof(full_path)); - - f = fopen(full_path, "r"); - if (!f) - return -EOPNOTSUPP; - - while (getline(&line, &len, f) != -1) { - line_invalid = 0; - pos = tg_start; - input = line; - - while ((token = strtok_r(input, " \t", &saveptr))) { - input = NULL; - - switch (pos) { - case tg_start: - if (strcmp(token, "*") != 0) - line_invalid = 1; - else - pos = tg_mac; - break; - case tg_mac: - mac_tmp = ether_aton(token); - if (!mac_tmp || memcmp(mac_tmp, mac, - ETH_ALEN) != 0) - line_invalid = 1; - else - pos = tg_via; - break; - case tg_via: - if (strcmp(token, "via") == 0) - pos = tg_originator; - break; - case tg_originator: - mac_tmp = ether_aton(token); - if (!mac_tmp) { - line_invalid = 1; - } else { - memcpy(mac_out, mac_tmp, ETH_ALEN); - found = true; - goto out; - } - break; - } - - if (line_invalid) - break; - } - } - -out: - if (f) - fclose(f); - free(line); - - if (found) - return 0; - else - return -ENOENT; -} - struct ether_addr *translate_mac(const char *mesh_iface, const struct ether_addr *mac) { struct ether_addr in_mac; static struct ether_addr out_mac; struct ether_addr *mac_result; - int ret; /* input mac has to be copied because it could be in the shared * ether_aton buffer @@ -456,10 +370,7 @@ struct ether_addr *translate_mac(const char *mesh_iface, if (!ether_addr_valid(in_mac.ether_addr_octet)) return mac_result; - ret = translate_mac_netlink(mesh_iface, &in_mac, mac_result); - - if (ret == -EOPNOTSUPP) - translate_mac_debugfs(mesh_iface, &in_mac, mac_result); + translate_mac_netlink(mesh_iface, &in_mac, mac_result); return mac_result; } diff --git a/icmp_helper.c b/icmp_helper.c index bfe99f0..26233c7 100644 --- a/icmp_helper.c +++ b/icmp_helper.c @@ -294,94 +294,6 @@ static int icmp_interface_update_parse(struct nl_msg *msg, void *arg) return NL_OK; } -static int get_nexthop_debugfs(const char *mesh_iface, - struct ether_addr *mac, - uint8_t nexthop[ETH_ALEN], - char ifname[IF_NAMESIZE]) -{ - char *tptr; - char *temp1, *temp2; - char *dest, *neigh, *iface; - int lnum, tnum; - struct ether_addr *mac_tmp; - char path[1024]; - FILE *f = NULL; - size_t len = 0; - char *line = NULL; - char *primary_info; - - debugfs_make_path(DEBUG_BATIF_PATH_FMT "/" "originators", mesh_iface, path, sizeof(path)); - - f = fopen(path, "r"); - if (!f) - return -EOPNOTSUPP; - - lnum = 0; - while (getline(&line, &len, f) != -1) { - lnum++; - - /* find primary mac */ - if (lnum == 1) { - primary_info = strstr(line, "MainIF/MAC: "); - if (!primary_info) - continue; - - primary_info += 12; - temp1 = strstr(primary_info, "/"); - if (!temp1) - continue; - - temp1++; - temp2 = strstr(line, " "); - if (!temp2) - continue; - - temp2[0] = '\0'; - mac_tmp = ether_aton(temp1); - if (!mac_tmp) - continue; - - memcpy(primary_mac, mac_tmp, ETH_ALEN); - } - - if (lnum < 3) - continue; - - /* find correct neighbor */ - for (tptr = line, tnum = 0;; tptr = NULL, tnum++) { - tptr = strtok_r(tptr, "\t []()", &temp2); - if (!tptr) - break; - switch (tnum) { - case 0: dest = tptr; break; - case 2: break; - case 3: neigh = tptr; break; - case 4: iface = tptr; break; - default: break; - } - } - if (tnum <= 4) - continue; - - mac_tmp = ether_aton(dest); - if (!mac_tmp || memcmp(mac_tmp, mac, ETH_ALEN) != 0) - continue; - - mac_tmp = ether_aton(neigh); - if (!mac_tmp) - continue; - - memcpy(nexthop, mac_tmp, ETH_ALEN); - strncpy(ifname, iface, IF_NAMESIZE); - ifname[IF_NAMESIZE - 1] = '\0'; - break; - } - free(line); - fclose(f); - - return 0; -} - static void icmp_interface_unmark(void) { struct icmp_interface *iface; @@ -478,8 +390,6 @@ int icmp_interface_write(const char *mesh_iface, memcpy(&mac, icmp_packet->dst, ETH_ALEN); ret = get_nexthop_netlink(mesh_iface, &mac, nexthop, ifname); - if (ret == -EOPNOTSUPP) - ret = get_nexthop_debugfs(mesh_iface, &mac, nexthop, ifname); if (ret < 0) goto dst_unreachable; diff --git a/ping.c b/ping.c index d798a5e..aa7cbc3 100644 --- a/ping.c +++ b/ping.c @@ -27,7 +27,6 @@ #include "main.h" #include "functions.h" #include "bat-hosts.h" -#include "debugfs.h" #include "icmp_helper.h" @@ -73,7 +72,6 @@ static int ping(struct state *state, int argc, char **argv) float min = 0.0, max = 0.0, avg = 0.0, mdev = 0.0; uint8_t last_rr_cur = 0, last_rr[BATADV_RR_LEN][ETH_ALEN]; size_t packet_len; - char *debugfs_mnt; int disable_translate_mac = 0; while ((optchar = getopt(argc, argv, "hc:i:t:RT")) != -1) { @@ -144,12 +142,6 @@ static int ping(struct state *state, int argc, char **argv) signal(SIGINT, sig_handler); signal(SIGTERM, sig_handler); - debugfs_mnt = debugfs_mount(NULL); - if (!debugfs_mnt) { - fprintf(stderr, "Error - can't mount or find debugfs\n"); - goto out; - } - icmp_interfaces_init(); packet_len = sizeof(struct batadv_icmp_packet); diff --git a/traceroute.c b/traceroute.c index 522d1c9..d810122 100644 --- a/traceroute.c +++ b/traceroute.c @@ -24,7 +24,6 @@ #include "main.h" #include "functions.h" #include "bat-hosts.h" -#include "debugfs.h" #include "icmp_helper.h" @@ -52,7 +51,6 @@ static int traceroute(struct state *state, int argc, char **argv) int ret = EXIT_FAILURE, res, i; int found_args = 1, optchar, seq_counter = 0, read_opt = USE_BAT_HOSTS; double time_delta[NUM_PACKETS]; - char *debugfs_mnt; int disable_translate_mac = 0; while ((optchar = getopt(argc, argv, "hnT")) != -1) { @@ -103,12 +101,6 @@ static int traceroute(struct state *state, int argc, char **argv) mac_string = ether_ntoa_long(dst_mac); - debugfs_mnt = debugfs_mount(NULL); - if (!debugfs_mnt) { - fprintf(stderr, "Error - can't mount or find debugfs\n"); - goto out; - } - icmp_interfaces_init(); memset(&icmp_packet_out, 0, sizeof(icmp_packet_out)); -- 2.20.1

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Re: [B.A.T.M.A.N.] Removing a node causing mesh to stop
by Lucas Pickstone 18 Apr '19

18 Apr '19

Hi Sven, Thanks for your super fast reply, and helpful direction and insights. On Fri, 12 Apr 2019 at 17:12, Sven Eckelmann <sven(a)narfation.org> wrote: > > On Friday, 12 April 2019 08:00:11 CEST Lucas Pickstone wrote: > > We have problem where our mesh is failing after a node is removed from > > it. We have a test set up of 3 computers (A, B and C) that can all > > directly see each other in an ad hoc wireless network. > > > > When we remove a node, the mesh between the remaining two nodes > > continues to work for a time (batman pings get through), but "batctl > > o" shows nothing recently last-seen. Once it times out after 200 > > seconds, the mesh dies (no further pings via batman get through). > > It is normal that the mesh closes down when there are no remaining paths to > the originators (your originators table was completely empty when the mesh > broke down). Since it looks like it is working in unicast while the last-seen > goes up, I would guess that broadcast packets on the underlying layer are > either not correctly send or not correctly received by the wifi driver/ > firmware on the remaining nodes. > > Unsure how this is triggered by removing a single node. But in case you are > using meshpoint interfaces with mesh_fwding=1 (which is wrong) and a higher > multicast rate, it could have been that the removed nodes was actually > relaying the bcast/mcast packets (which might be send with a higher rate as > suggested on open-mesh.org - or which maybe was automatically selected by the > ath10k firmware) and the remaining nodes B+C cannot really communicate on the > selected mcast/bcast rate directly with each other. > > > If we bring the disconnected node back up, everything goes back to normal. > > What interface mode are you using? meshpoint without mesh_fwding (yes, make > sure that the mesh parameter mesh_fwding is really set to 0 [1] during your > tests)? Or IBSS (which would usually mean an ancient firmware or Ben Greear's > firmware)? > > > We're a little bit stuck on how to diagnose/debug what is happening. > > We thought that maybe the underlying ad hoc network was causing > > issues, but it seems okay - we can assign IP addresses on the wlan > > interfaces and ping without interruption through the entire test. > > Please check whether it can receive/send broadcast packets in both directions > during the test (according to your TQ with at least 2/3 of success with a > bcast ping-pong). This is how OGMs (to generate the content of the originators > table) are sent. Also make sure that your receive+send the stuff as actual > broadcast packets. There are ways to let the wifi layer convert these > broadcast/mcast frames to unicast frames - and this is not allowed for batman- > adv because B.A.T.M.A.N. IV needs to measure the loss for broadcast packets - > unicast packets are retransmitted automatically by the wifi components (which > we don't want). We did some more testing yesterday and concluded the issue was with the SparkLAN driver. The driver was provided directly by SparkLAN (proprietary, I assume), but we did have a few other issues with it in the past requiring them to give us patches - our confidence in it isn't too high. It seemed to be running in IBSS mode. We've had good success so far using an RTL8188RU based device, as well as a Ralink device. These worked out of the box with the built in Linux drivers, which increases our confidence level in the devices/drivers. > [...] > > Environment (identical on all computers): > > - WiFi Card : SparkLAN WPEQ-160ACN(BT) > > It is a QCA9377-7 miniPCIe, right? Is it using the PCI pins or the USB > pins [2]? Yes, it is a QCA9377-7 and uses PCI pins. > > - WiFi driver: nl80211 > > This cannot be the driver - this is the module which allows userspace to > communicate with cfg80211 (and vice versa). Maybe it is ath10k, ath10k-ct or > the proprietary QCA monster (which recently received semi working cfg80211 > support). > > Kind regards, > Sven > > [1] iw dev wlan0 get mesh_param mesh_fwding > iw dev wlan0 set mesh_param mesh_fwding 0 > [2] https://www.qualcomm.com/media/documents/files/qca9377-product-brief.pdf > > PS: Not the best idea to send from a DMARC (quarantine policy) domain to a > mailing list. Oops, sorry about that. Thanks again for all your help. Lucas Pickstone

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[B.A.T.M.A.N.] batman-adv release mailing list or RSS feed?
by Ralf Jung 15 Apr '19

15 Apr '19

Hi all, is there a mailing list or RSS feed dedicated to batman-adv releases? We are running latest upstream batman-adv release on a couple of servers, so we'd like to know when we have to (manually) update our machines -- and currently the best I can do is try to remember to check your website regularly, which of course does not actually work in practice. Kind regards, Ralf

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Removing a node causing mesh to stop
by Lucas Pickstone 12 Apr '19

12 Apr '19

Hi, We have problem where our mesh is failing after a node is removed from it. We have a test set up of 3 computers (A, B and C) that can all directly see each other in an ad hoc wireless network. When we remove a node, the mesh between the remaining two nodes continues to work for a time (batman pings get through), but "batctl o" shows nothing recently last-seen. Once it times out after 200 seconds, the mesh dies (no further pings via batman get through). If we bring the disconnected node back up, everything goes back to normal. Has anyone else seen this problem or had any experience with something similar? We're a little bit stuck on how to diagnose/debug what is happening. We thought that maybe the underlying ad hoc network was causing issues, but it seems okay - we can assign IP addresses on the wlan interfaces and ping without interruption through the entire test. Here is a link to a video showing the behaviour from node C, some time after node A was removed. Both node B and C should still be connected. https://www.youtube.com/watch?v=Hj_0OFvgTt0 - The terminal at the top shows the batman ping to node B (from node C). - The middle terminal shows the standard ping via the adhoc network wlan interface to node B (from node C). - The lower window shows the B.A.T.M.A.N. originators table (as seen by node C). Environment (identical on all computers): - WiFi Card : SparkLAN WPEQ-160ACN(BT) - WiFi driver: nl80211 - batman-adv: 2019.1 - batctl: 2019.1 - Linux Kernel: 4.4.0-130 Ubuntu 16.04 LTS Any thoughts would be greatly appreciated. Thanks, Lucas Pickstone

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[B.A.T.M.A.N.] [PATCH v4 0/2] batman-adv: increase DAT DHT timeout
by Linus Lüssing 08 Apr '19

08 Apr '19

Hi, This is the fourth attempt to increase the DAT DHT timeout to reduce the amount of broadcasted ARP Replies. To increase the timeout only for DAT DHT entries added via DHT-PUT but not for any other entry in the DAT cache the DAT cache and DAT DHT concepts are first split into two separate hash tables (PATCH 1/2). PATCH 2/2 then increases the timeout for DAT DHT entries from 5 to 30 minutes. The motivation for this patchset is based on the observations made here: https://www.open-mesh.org/projects/batman-adv/wiki/DAT_DHCP_Snooping Regards, Linus --- Changelog v2: formerly: "batman-adv: Increase DHCP snooped DAT entry purge timeout in DHT" (https://patchwork.open-mesh.org/patch/17364/) - removed the extended timeouts flag in the DHT-PUT messages introduced in v1 again - removed DHCP dependency Changelog v3: formerly: "batman-adv: Increase purge timeout on DAT DHT candidates" https://patchwork.open-mesh.org/patch/17728/ - fixed the potential jiffies overflow and jiffies initialization issues by replacing the last_dht_update timeout variable with a split of DAT cache and DAT DHT into two separate hash tables -> instead of maintaining two timeouts in one DAT entry two DAT entries are created and maintained in their respective DAT cache and DAT DHT hash tables Changelog v4: - rebased to: acfc9a214d01695 ("batman-adv: genetlink: make policy common to family")

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[B.A.T.M.A.N.] About making batman-adv mesh network invisible (by encrypting Beacon frame)
by Xuebing Wang 08 Apr '19

08 Apr '19

Hi community, We have batman-adv + OpenWRT + ath9k chip + ath9k driver reliably running for about 2 years. The biggest batman-adv mesh network is with 100+ nodes. As this is a closed network, we have a new requirement which is to make our batman-adv mesh network invisible, although the current SSID is just some meaningless characters. One thought is hidden_ssid. But, it seems hidden_ssid is only supported for AP mode (not IBSS mode). 802.11w does not protect Beacon frame (because it is before four-ways handshake). As this is a closed network, what about encrypting Beacon (maybe all management frames later) using a hard-coded key in wpa_supplicant? Thanks for your help. Xuebing Wang

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[B.A.T.M.A.N.] [PATCH] batman-adv: Increase purge timeout on DAT DHT candidates
by Linus Lüssing 07 Apr '19

07 Apr '19

Currently, the DHT_GET messages of the DAT will likely be left unanswered due to the following issues: When a node has a matching DAT Cache entry for a local ARP Request then this node will answer it directly with the information provided by the cache. This however, will likely lead to missing ARP Replies from the original host. Which in turn leads to the DAT cache not being updated. Then the local DAT cache entry will time out, triggering a unicasted DHT_GET. However, as the 5min. timeout has passed, the DAT DHT candidates will likely have purged their entry, too. So basically this results in an ARP Request broadcast fallback every five minutes. A second issue is that it is quite common that a host which has long gone offline will be tried to be contacted by another one at some remote period larger than the current 5min. timeout. This too leads to flooded ARP Requests. With this patch the purge timeout for local DAT cache entries and entries submitted via a DHT_PUT message is differentiated: While the former stays at 5min. the latter is increased to 30min. Which decreases the rate of broadcasted ARP Requests. Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Some old investigations and analysis seemed to indicate a potential reduction of 91.71% of unanswered ARP Requests (45min: 97.95%, 60min: 98.95%): https://www.open-mesh.org/projects/batman-adv/wiki/DAT_DHCP_Snooping This patch is rebased on top of: "batman-adv: DHCP snooping for DAT" And it is a follow-up of: "batman-adv: Increase DHCP snooped DAT entry purge timeout in DHT" - https://patchwork.open-mesh.org/patch/17364/ --- net/batman-adv/distributed-arp-table.c | 39 ++++++++++++++++++++++------------ net/batman-adv/distributed-arp-table.h | 3 ++- net/batman-adv/main.h | 2 ++ net/batman-adv/routing.c | 8 ++++--- net/batman-adv/types.h | 5 +++++ 5 files changed, 39 insertions(+), 18 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 899ab051..34898abf 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -152,7 +152,9 @@ static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) { return batadv_has_timed_out(dat_entry->last_update, - BATADV_DAT_ENTRY_TIMEOUT); + BATADV_DAT_ENTRY_TIMEOUT) && + batadv_has_timed_out(dat_entry->last_dht_update, + BATADV_DAT_DHT_TIMEOUT); } /** @@ -369,9 +371,11 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, * @ip: ipv4 to add/edit * @mac_addr: mac address to assign to the given ipv4 * @vid: VLAN identifier + * @extended_timeout: whether this should be cached with an extended timeout */ -static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, - u8 *mac_addr, unsigned short vid) +static void +batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, u8 *mac_addr, + unsigned short vid, bool extended_timeout) { struct batadv_dat_entry *dat_entry; int hash_added; @@ -382,6 +386,10 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) ether_addr_copy(dat_entry->mac_addr, mac_addr); dat_entry->last_update = jiffies; + + if (extended_timeout) + dat_entry->last_dht_update = jiffies; + batadv_dbg(BATADV_DBG_DAT, bat_priv, "Entry updated: %pI4 %pM (vid: %d)\n", &dat_entry->ip, dat_entry->mac_addr, @@ -397,6 +405,7 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, dat_entry->vid = vid; ether_addr_copy(dat_entry->mac_addr, mac_addr); dat_entry->last_update = jiffies; + dat_entry->last_dht_update = extended_timeout ? jiffies : 0; kref_init(&dat_entry->refcount); kref_get(&dat_entry->refcount); @@ -1229,7 +1238,7 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, hw_src = batadv_arp_hw_src(skb, hdr_size); ip_dst = batadv_arp_ip_dst(skb, hdr_size); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); if (dat_entry) { @@ -1322,7 +1331,7 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST"); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); if (!dat_entry) @@ -1386,8 +1395,8 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, hw_dst = batadv_arp_hw_dst(skb, hdr_size); ip_dst = batadv_arp_ip_dst(skb, hdr_size); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, false); /* Send the ARP reply to the candidates for both the IP addresses that * the node obtained from the ARP reply @@ -1402,12 +1411,14 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, * @bat_priv: the bat priv with all the soft interface information * @skb: packet to check * @hdr_size: size of the encapsulation header + * @is_dht_put: whether this is a BATADV_P_DAT_DHT_PUT message * * Return: true if the packet was snooped and consumed by DAT. False if the * packet has to be delivered to the interface */ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, - struct sk_buff *skb, int hdr_size) + struct sk_buff *skb, int hdr_size, + bool is_dht_put) { struct batadv_dat_entry *dat_entry = NULL; u16 type; @@ -1450,8 +1461,8 @@ bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, /* Update our internal cache with both the IP addresses the node got * within the ARP reply */ - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, is_dht_put); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, is_dht_put); /* If BLA is enabled, only forward ARP replies if we have claimed the * source of the ARP reply or if no one else of the same backbone has @@ -1705,8 +1716,8 @@ static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr, skb_set_network_header(skb, ETH_HLEN); - batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); - batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid, false); + batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid, false); batadv_dat_send_data(bat_priv, skb, yiaddr, vid, BATADV_P_DAT_DHT_PUT); batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); @@ -1827,8 +1838,8 @@ void batadv_dat_snoop_incoming_dhcp_ack(struct batadv_priv *bat_priv, hw_src = ethhdr->h_source; vid = batadv_dat_get_vid(skb, &hdr_size); - batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); - batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); + batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid, false); + batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid, false); batadv_dbg(BATADV_DBG_DAT, bat_priv, "Snooped from incoming DHCPACK (server address): %pI4, %pM (vid: %i)\n", diff --git a/net/batman-adv/distributed-arp-table.h b/net/batman-adv/distributed-arp-table.h index 68c0ff32..21dbf285 100644 --- a/net/batman-adv/distributed-arp-table.h +++ b/net/batman-adv/distributed-arp-table.h @@ -45,7 +45,8 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, 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); + struct sk_buff *skb, int hdr_size, + bool is_dht_put); void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv, struct sk_buff *skb, __be16 proto, diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 05cb9080..6c1488f8 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -51,6 +51,8 @@ #define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */ #define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */ #define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */ +#define BATADV_DAT_DHT_TIMEOUT (30 * 60000) /* 30 mins in milliseconds */ + /* sliding packet range of received originator messages in sequence numbers * (should be a multiple of our word size) */ diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index cae0e5dd..2b5d50ab 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -974,7 +974,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; int ret = NET_RX_DROP; - bool is4addr, is_gw; + bool is4addr, is_gw, is_dht_put = false; unicast_packet = (struct batadv_unicast_packet *)skb->data; is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; @@ -1033,6 +1033,8 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, orig_addr = unicast_4addr_packet->src; orig_node = batadv_orig_hash_find(bat_priv, orig_addr); + } else if (subtype == BATADV_P_DAT_DHT_PUT) { + is_dht_put = true; } } @@ -1040,7 +1042,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb, hdr_size)) goto rx_success; if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, - hdr_size)) + hdr_size, is_dht_put)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); @@ -1277,7 +1279,7 @@ int batadv_recv_bcast_packet(struct sk_buff *skb, if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) goto rx_success; - if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) + if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size, false)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a21b34ed..74801d79 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -2280,6 +2280,11 @@ struct batadv_dat_entry { */ unsigned long last_update; + /** + * @last_dht_update: time in jiffies when a DHT_PUT was last received + */ + unsigned long last_dht_update; + /** @hash_entry: hlist node for &batadv_priv_dat.hash */ struct hlist_node hash_entry; -- 2.11.0

4 7

[B.A.T.M.A.N.] [PATCH] batctl: add dat_dht command
by Linus Lüssing 07 Apr '19

07 Apr '19

This adds a dat_dht command to query the DHT part of DAT in batman-adv. Signed-off-by: Linus Lüssing <linus.luessing(a)c0d3.blue> --- Makefile | 1 + README.rst | 27 +++++++++- batadv_packet.h | 4 +- batman_adv.h | 5 ++ dat_cache.c | 2 +- dat_dht.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++ debug.h | 1 + man/batctl.8 | 3 ++ 8 files changed, 173 insertions(+), 3 deletions(-) create mode 100644 dat_dht.c diff --git a/Makefile b/Makefile index df8b7b9..94f3321 100755 --- a/Makefile +++ b/Makefile @@ -44,6 +44,7 @@ $(eval $(call add_command,bonding,y)) $(eval $(call add_command,bridge_loop_avoidance,y)) $(eval $(call add_command,claimtable,y)) $(eval $(call add_command,dat_cache,y)) +$(eval $(call add_command,dat_dht,y)) $(eval $(call add_command,distributed_arp_table,y)) $(eval $(call add_command,event,y)) $(eval $(call add_command,fragmentation,y)) diff --git a/README.rst b/README.rst index 03ea5e5..97ca394 100644 --- a/README.rst +++ b/README.rst @@ -652,7 +652,32 @@ Usage:: Example:: - Distributed ARP Table (bat0): + Distributed ARP Table Cache (bat0): + IPv4 MAC last-seen + * 172.100.0.1 b6:9b:d0:ea:b1:13 0:00 + +where + +IPv4: + is the IP address of a client in the mesh network +MAC: + is the MAC address associated to that IP +last-seen: + is the amount of time since last refresh of this entry + + +batctl dat_dht +================= + +display the local D.A.T. DHT + +Usage:: + + batctl dat_dht|dd + +Example:: + + Distributed ARP Table DHT (bat0): IPv4 MAC last-seen * 172.100.0.1 b6:9b:d0:ea:b1:13 0:00 diff --git a/batadv_packet.h b/batadv_packet.h index 4ebc213..fb42e3d 100644 --- a/batadv_packet.h +++ b/batadv_packet.h @@ -58,13 +58,15 @@ enum batadv_packettype { * @BATADV_P_DATA: user payload * @BATADV_P_DAT_DHT_GET: DHT request message * @BATADV_P_DAT_DHT_PUT: DHT store message - * @BATADV_P_DAT_CACHE_REPLY: ARP reply generated by DAT + * @BATADV_P_DAT_CACHE_REPLY: deprecated: use BATADV_P_DAT_DHT_REPLY instead + * @BATADV_P_DAT_DHT_REPLY: ARP reply generated by DAT */ enum batadv_subtype { BATADV_P_DATA = 0x01, BATADV_P_DAT_DHT_GET = 0x02, BATADV_P_DAT_DHT_PUT = 0x03, BATADV_P_DAT_CACHE_REPLY = 0x04, + BATADV_P_DAT_DHT_REPLY = 0x04, }; /* this file is included by batctl which needs these defines */ diff --git a/batman_adv.h b/batman_adv.h index 67f4636..e4bcc23 100644 --- a/batman_adv.h +++ b/batman_adv.h @@ -612,6 +612,11 @@ enum batadv_nl_commands { */ BATADV_CMD_SET_VLAN, + /** + * @BATADV_CMD_GET_DAT_DHT: Query list of DAT DHT entries + */ + BATADV_CMD_GET_DAT_DHT, + /* add new commands above here */ /** diff --git a/dat_cache.c b/dat_cache.c index 4a8a082..5c947c0 100644 --- a/dat_cache.c +++ b/dat_cache.c @@ -106,7 +106,7 @@ static int netlink_print_dat_cache(struct state *state, char *orig_iface, char *header; int ret; - ret = asprintf(&header, "Distributed ARP Table (%s):\n%s\n", + ret = asprintf(&header, "Distributed ARP Table Cache (%s):\n%s\n", state->mesh_iface, " IPv4 MAC VID last-seen"); diff --git a/dat_dht.c b/dat_dht.c new file mode 100644 index 0000000..8c7897c --- /dev/null +++ b/dat_dht.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2009-2019 B.A.T.M.A.N. contributors: + * + * Marek Lindner <mareklindner(a)neomailbox.ch> + * + * License-Filename: LICENSES/preferred/GPL-2.0 + */ + +#include <arpa/inet.h> +#include <netinet/if_ether.h> +#include <netinet/in.h> +#include <netlink/netlink.h> +#include <netlink/genl/genl.h> +#include <netlink/genl/ctrl.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <sys/socket.h> + +#include "batadv_packet.h" +#include "batman_adv.h" +#include "bat-hosts.h" +#include "debug.h" +#include "functions.h" +#include "main.h" +#include "netlink.h" + +static const int dat_dht_mandatory[] = { + BATADV_ATTR_DAT_CACHE_IP4ADDRESS, + BATADV_ATTR_DAT_CACHE_HWADDRESS, + BATADV_ATTR_DAT_CACHE_VID, + BATADV_ATTR_LAST_SEEN_MSECS, +}; + +static int dat_dht_callback(struct nl_msg *msg, void *arg) +{ + int last_seen_msecs, last_seen_secs, last_seen_mins; + struct nlattr *attrs[BATADV_ATTR_MAX+1]; + struct nlmsghdr *nlh = nlmsg_hdr(msg); + struct print_opts *opts = arg; + struct bat_host *bat_host; + struct genlmsghdr *ghdr; + struct in_addr in_addr; + uint8_t *hwaddr; + int16_t vid; + char *addr; + + if (!genlmsg_valid_hdr(nlh, 0)) { + fputs("Received invalid data from kernel.\n", stderr); + exit(1); + } + + ghdr = nlmsg_data(nlh); + + if (ghdr->cmd != BATADV_CMD_GET_DAT_DHT) + return NL_OK; + + if (nla_parse(attrs, BATADV_ATTR_MAX, genlmsg_attrdata(ghdr, 0), + genlmsg_len(ghdr), batadv_netlink_policy)) { + fputs("Received invalid data from kernel.\n", stderr); + exit(1); + } + + if (missing_mandatory_attrs(attrs, dat_dht_mandatory, + ARRAY_SIZE(dat_dht_mandatory))) { + fputs("Missing attributes from kernel\n", stderr); + exit(1); + } + + in_addr.s_addr = nla_get_u32(attrs[BATADV_ATTR_DAT_CACHE_IP4ADDRESS]); + addr = inet_ntoa(in_addr); + hwaddr = nla_data(attrs[BATADV_ATTR_DAT_CACHE_HWADDRESS]); + vid = nla_get_u16(attrs[BATADV_ATTR_DAT_CACHE_VID]); + + last_seen_msecs = nla_get_u32(attrs[BATADV_ATTR_LAST_SEEN_MSECS]); + last_seen_mins = last_seen_msecs / 60000; + last_seen_msecs = last_seen_msecs % 60000; + last_seen_secs = last_seen_msecs / 1000; + + if (opts->read_opt & MULTICAST_ONLY && !(addr[0] & 0x01)) + return NL_OK; + + if (opts->read_opt & UNICAST_ONLY && (addr[0] & 0x01)) + return NL_OK; + + printf(" * %15s ", addr); + + bat_host = bat_hosts_find_by_mac((char *)hwaddr); + if (!(opts->read_opt & USE_BAT_HOSTS) || !bat_host) + printf("%02x:%02x:%02x:%02x:%02x:%02x ", + hwaddr[0], hwaddr[1], hwaddr[2], + hwaddr[3], hwaddr[4], hwaddr[5]); + else + printf("%17s ", bat_host->name); + + printf("%4i %6i:%02i\n", + BATADV_PRINT_VID(vid), last_seen_mins, last_seen_secs); + + return NL_OK; +} + +static int netlink_print_dat_dht(struct state *state, char *orig_iface, + int read_opts, float orig_timeout, + float watch_interval) +{ + char *header; + int ret; + + ret = asprintf(&header, "Distributed ARP Table DHT (%s):\n%s\n", + state->mesh_iface, + " IPv4 MAC VID last-seen"); + + if (ret < 0) + return ret; + + ret = netlink_print_common(state, orig_iface, read_opts, + orig_timeout, watch_interval, header, + BATADV_CMD_GET_DAT_DHT, + dat_dht_callback); + + free(header); + return ret; +} + +static struct debug_table_data batctl_debug_table_dat_dht = { + .debugfs_name = DEBUG_DAT_DHT, + .header_lines = 2, + .netlink_fn = netlink_print_dat_dht, +}; + +COMMAND_NAMED(DEBUGTABLE, dat_dht, "dd", handle_debug_table, + COMMAND_FLAG_MESH_IFACE | COMMAND_FLAG_NETLINK, + &batctl_debug_table_dat_dht, ""); diff --git a/debug.h b/debug.h index 3294361..e6353ab 100644 --- a/debug.h +++ b/debug.h @@ -17,6 +17,7 @@ #define DEBUG_BACKBONETABLE "bla_backbone_table" #define DEBUG_CLAIMTABLE "bla_claim_table" #define DEBUG_DAT_CACHE "dat_cache" +#define DEBUG_DAT_DHT "dat_dht" #define DEBUG_NC_NODES "nc_nodes" #define DEBUG_MCAST_FLAGS "mcast_flags" #define DEBUG_LOG "log" diff --git a/man/batctl.8 b/man/batctl.8 index 8d7332a..fb1dd02 100644 --- a/man/batctl.8 +++ b/man/batctl.8 @@ -276,6 +276,9 @@ List of debug tables: \- dat_cache|dc (compile time option) .RE .RS 10 +\- dat_dht|dd (compile time option) +.RE +.RS 10 \- nc_nodes|nn (compile time option) .RE .RS 10 -- 2.20.1

1 0

[B.A.T.M.A.N.] [PATCH v3 0/2] batman-adv: increase DAT DHT timeout
by Linus Lüssing 07 Apr '19

07 Apr '19

Hi, This is the third attempt to increase the DAT DHT timeout to reduce the amount of broadcasted ARP Replies. To increase the timeout only for DAT DHT entries added via DHT-PUT but not for any other entry in the DAT cache the DAT cache and DAT DHT concepts are first split into two separate hash tables (PATCH 1/2). PATCH 2/2 then increases the timeout for DAT DHT entries from 5 to 30 minutes. The motivation for this patchset is based on the observations made here: https://www.open-mesh.org/projects/batman-adv/wiki/DAT_DHCP_Snooping Regards, Linus --- Changelog v2: formerly: "batman-adv: Increase DHCP snooped DAT entry purge timeout in DHT" (https://patchwork.open-mesh.org/patch/17364/) - removed the extended timeouts flag in the DHT-PUT messages introduced in v1 again - removed DHCP dependency Changelog v3: formerly: "batman-adv: Increase purge timeout on DAT DHT candidates" https://patchwork.open-mesh.org/patch/17728/ - fixed the potential jiffies overflow and jiffies initialization issues by replacing the last_dht_update timeout variable with a split of DAT cache and DAT DHT into two separate hash tables -> instead of maintaining two timeouts in one DAT entry two DAT entries are created and maintained in their respective DAT cache and DAT DHT hash tables

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B.A.T.M.A.N April 2019