B.A.T.M.A.N November 2018

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

14 participants
23 discussions

[B.A.T.M.A.N.] [PATCH maint] batman-adv: Use explicit tvlv padding for ELP packets
by Sven Eckelmann 03 Nov '18

03 Nov '18

The announcement messages of batman-adv COMPAT_VERSION 15 have the possibility to announce additional information via a dynamic TVLV part. This part is optional for the ELP packets and currently not parsed by the Linux implementation. Still out-of-tree versions are using it to transport things like neighbor hashes to optimize the rebroadcast behavior. Since the ELP broadcast packets are smaller than the minimal ethernet packet, it often has to be padded. This is often done (as specified in RFC894) with octets of zero and thus work perfectly fine with the TVLV part (making it a zero length and thus empty). But not all ethernet compatible hardware seems to follow this advice. To avoid ambiguous situations when parsing the TVLV header, just force the 4 bytes (TVLV length + padding) after the required ELP header to zero. Fixes: a4b88af77e28 ("batman-adv: ELP - adding basic infrastructure") Reported-by: Linus Lüssing <linus.luessing(a)c0d3.blue> Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/bat_v_elp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index 9f481cfd..e8090f09 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -352,19 +352,21 @@ static void batadv_v_elp_periodic_work(struct work_struct *work) */ int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) { + static const size_t tvlv_padding = sizeof(__be32); struct batadv_elp_packet *elp_packet; unsigned char *elp_buff; u32 random_seqno; size_t size; int res = -ENOMEM; - size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN; + size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding; hard_iface->bat_v.elp_skb = dev_alloc_skb(size); if (!hard_iface->bat_v.elp_skb) goto out; skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN); - elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); + elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, + BATADV_ELP_HLEN + tvlv_padding); elp_packet = (struct batadv_elp_packet *)elp_buff; elp_packet->packet_type = BATADV_ELP; -- 2.19.1

1 1

[B.A.T.M.A.N.] Question on 'batctl o'
by John Gorkos 02 Nov '18

02 Nov '18

What does the leading asterisk indicate by an originator in 'batctl o'? i.e.: [B.A.T.M.A.N. adv 2017.3, MainIF/MAC: wlan0/00:c0:ca:97:4c:34 (bat0/e2:9d:52:8c:34:83 BATMAN_IV)] Originator last-seen (#/255) Nexthop [outgoingIF] * 00:0f:00:54:9b:d4 0.130s (197) 00:0f:00:54:9b:d4 [ wlan0] * b8:27:eb:a0:2a:53 0.830s (225) b8:27:eb:a0:2a:53 [ wlan0] Regards, John Gorkos

2 1

[B.A.T.M.A.N.] [PATCH v3] alfred: Request MAC resolution for IPv4 address not in ARP cache
by Jonathan Haws 01 Nov '18

01 Nov '18

When using IPv4, if the remote server is not yet in the ARP cache, the MAC resolution will fail and data appear to not be shared via alfred. Add a routine (modified from batctl sources) to request MAC resolution by simply sending a datagram to the discard port (UDP/9). This adds the remote MAC to the ARP cache, resulting in successful MAC resolution. Fixes: c7da798113a2 ("alfred: IPv4 multicast distribution support.") Signed-off-by: Jonathan Haws <jhaws(a)sdl.usu.edu> --- util.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/util.c b/util.c index dd3f00f..0794792 100644 --- a/util.c +++ b/util.c @@ -30,6 +30,7 @@ #include <sys/ioctl.h> #include <sys/time.h> #include <time.h> +#include <unistd.h> #include "alfred.h" int time_diff(struct timespec *tv1, struct timespec *tv2, @@ -80,11 +81,35 @@ bool is_valid_ether_addr(uint8_t addr[ETH_ALEN]) return true; } +static void ipv4_request_mac_resolve(const alfred_addr *addr) +{ + const struct sockaddr *sockaddr; + struct sockaddr_in inet4; + size_t sockaddr_len; + int sock; + char t = 0; + + sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (sock < 0) + return; + + memset(&inet4, 0, sizeof(inet4)); + inet4.sin_family = AF_INET; + inet4.sin_port = htons(9); + inet4.sin_addr.s_addr = addr->ipv4.s_addr; + sockaddr = (const struct sockaddr *)&inet4; + sockaddr_len = sizeof(inet4); + + sendto(sock, &t, sizeof(t), 0, sockaddr, sockaddr_len); + close(sock); +} + int ipv4_arp_request(struct interface *interface, const alfred_addr *addr, struct ether_addr *mac) { struct arpreq arpreq; struct sockaddr_in *sin; + int retries = 1; memset(&arpreq, 0, sizeof(arpreq)); memset(mac, 0, ETH_ALEN); @@ -96,8 +121,13 @@ int ipv4_arp_request(struct interface *interface, const alfred_addr *addr, strncpy(arpreq.arp_dev, interface->interface, sizeof(arpreq.arp_dev)); arpreq.arp_dev[sizeof(arpreq.arp_dev) - 1] = '\0'; - if (ioctl(interface->netsock, SIOCGARP, &arpreq) < 0) - return -1; + while ((ioctl(interface->netsock, SIOCGARP, &arpreq) < 0) || !(arpreq.arp_flags & ATF_COM)) { + ipv4_request_mac_resolve(addr); + usleep(200000); + + if (retries-- == 0) + break; + } if (arpreq.arp_flags & ATF_COM) { memcpy(mac, arpreq.arp_ha.sa_data, sizeof(*mac)); -- 2.17.1

3 2

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

B.A.T.M.A.N November 2018