[Dnsmasq-discuss] ra-only segfault
Just happened so I am still collecting information but ... having a conf file with nothing much specified but: ... interface=eth2 dhcp-range=fd00:ff:11::2,ra-only ... results in a segfault I got this on real hardware with libvirt but have been able to duplicate it virtually. Attached are the syslog messages from the guests syslog. dnsmasq 2.65-4 on Fedora 18. Gene Mar 11 11:20:02 f18test systemd[1]: Starting DNS caching server Mar 11 11:20:02 f18test kernel: [ 581.680208] dnsmasq[1987]: segfault at 0 ip 00330a285abe sp 7fff10a61478 error 6 in libc-2.16.so[330a20+1ad000] Mar 11 11:20:02 f18test systemd[1]: Started DNS caching server.. Mar 11 11:20:02 f18test dnsmasq[1987]: started, version 2.65 cachesize 150 Mar 11 11:20:02 f18test dnsmasq[1987]: compile time options: IPv6 GNU-getopt DBus no-i18n no-IDN DHCP DHCPv6 no-Lua TFTP no-conntrack Mar 11 11:20:02 f18test dnsmasq-dhcp[1987]: IPv6 router advertisement enabled Mar 11 11:20:02 f18test systemd[1]: dnsmasq.service: main process exited, code=killed, status=11/SEGV Mar 11 11:20:02 f18test systemd[1]: Unit dnsmasq.service entered failed state Mar 11 11:25:21 f18test systemd[1]: Starting Cleanup of Temporary Directories... Mar 11 11:25:21 f18test systemd-tmpfiles[2021]: stat(/run/user/1000/gvfs) failed: Permission denied Mar 11 11:25:21 f18test systemd[1]: Started Cleanup of Temporary Directories. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] ra-only segfault
On 11/03/13 15:33, Gene Czarcinski wrote: Just happened so I am still collecting information but ... having a conf file with nothing much specified but: ... interface=eth2 dhcp-range=fd00:ff:11::2,ra-only ... results in a segfault I got this on real hardware with libvirt but have been able to duplicate it virtually. Attached are the syslog messages from the guests syslog. dnsmasq 2.65-4 on Fedora 18. Gene I just fed exactly those options into 2.65 as released by me, and it didn't crash, so we're going to have to pin this down a bit more. Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Sometimes forgets to hand out known dhcp-host IP
On Fri, Mar 8, 2013 at 6:14 PM, Simon Kelley si...@thekelleys.org.ukwrote: On 07/03/13 14:34, hansen wrote: Hi dnsmasq'ueraders :) I have a small network, where I am trying to split my network into to ranges. One range for local machines and another range for guests. On two different interfaces connected to dnsmasq. Usually I don't have any problems, but sometimes my local machines end up on the guest range network. If I release the DHCP on the machine and reboot it, then it is 50/50 if the go back to local network or end up on guest network again. Is this network setup just bad and not possible to behave as I expect - or is it just a configuration mistake? I am running dnsmasq 2.65 on FreeBSD 7.4. Looking at the changelog it seems like the feature I'm looking for was removed in 2.63 (Remove the interface:interface argument in --dhcp-range) No that feature won't fix the problem. The problem is that you have two interfaces (em1 and em2) connected to the same broadcast domain. That's not something that dnsmasq knows how to deal with, and it gets confused when is gives a client an address associated with one interface, and then it turns up on a different interface. Can you use one physical interface on the machine running dnsmasq, and give it two addresses? Hi Simon, Thanks for replying. I do think it's possible to create virtual IPs on one physical interface. So you don't think it would be a problem if two VIPs broadcasts? Not sure how the ideal setup would be, but probably something with VLAN - the switch doesn't do that and don't have the funds right now. -hansen ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Sometimes forgets to hand out known dhcp-host IP
On 11/03/13 16:33, hansen wrote: On Fri, Mar 8, 2013 at 6:14 PM, Simon Kelley si...@thekelleys.org.uk mailto:si...@thekelleys.org.uk wrote: On 07/03/13 14:34, hansen wrote: Hi dnsmasq'ueraders :) I have a small network, where I am trying to split my network into to ranges. One range for local machines and another range for guests. On two different interfaces connected to dnsmasq. Usually I don't have any problems, but sometimes my local machines end up on the guest range network. If I release the DHCP on the machine and reboot it, then it is 50/50 if the go back to local network or end up on guest network again. Is this network setup just bad and not possible to behave as I expect - or is it just a configuration mistake? I am running dnsmasq 2.65 on FreeBSD 7.4. Looking at the changelog it seems like the feature I'm looking for was removed in 2.63 (Remove the interface:interface argument in --dhcp-range) No that feature won't fix the problem. The problem is that you have two interfaces (em1 and em2) connected to the same broadcast domain. That's not something that dnsmasq knows how to deal with, and it gets confused when is gives a client an address associated with one interface, and then it turns up on a different interface. Can you use one physical interface on the machine running dnsmasq, and give it two addresses? Hi Simon, Thanks for replying. I do think it's possible to create virtual IPs on one physical interface. I'm sure it is. For FreeBSD, the magic keyword is IP alias One of many google hits that describes it is: http://www.unixwerk.eu/bsd/ipalias.html So you don't think it would be a problem if two VIPs broadcasts? It's fine, because dnsmasq will know that both IPs are in the same broadcast-domain (ie connected to the same virtual wire). The problems you were seeing are because dnsmasq is treating the two interfaces as being connected to different interfaces, and trying to keep up with a host that lokos like it's moving randomly between the two networks. In the long term, dnsmasq needs something like the ISC shared network keyword for this sort of situation, but that won't solve you immediate problem. Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] ra-only segfault
On 03/11/2013 12:22 PM, Simon Kelley wrote: On 11/03/13 15:33, Gene Czarcinski wrote: Just happened so I am still collecting information but ... having a conf file with nothing much specified but: ... interface=eth2 dhcp-range=fd00:ff:11::2,ra-only ... results in a segfault I got this on real hardware with libvirt but have been able to duplicate it virtually. Attached are the syslog messages from the guests syslog. dnsmasq 2.65-4 on Fedora 18. Gene I just fed exactly those options into 2.65 as released by me, and it didn't crash, so we're going to have to pin this down a bit more. It would be too easy to be that repeatable. I will set something up to be simple and yet demonstrate the failure. Gene ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] ra-only segfault
On 03/11/2013 12:44 PM, Gene Czarcinski wrote: On 03/11/2013 12:22 PM, Simon Kelley wrote: On 11/03/13 15:33, Gene Czarcinski wrote: Just happened so I am still collecting information but ... having a conf file with nothing much specified but: ... interface=eth2 dhcp-range=fd00:ff:11::2,ra-only ... results in a segfault I got this on real hardware with libvirt but have been able to duplicate it virtually. Attached are the syslog messages from the guests syslog. dnsmasq 2.65-4 on Fedora 18. Gene I just fed exactly those options into 2.65 as released by me, and it didn't crash, so we're going to have to pin this down a bit more. It would be too easy to be that repeatable. I will set something up to be simple and yet demonstrate the failure. More data. I took the dnsmasq.conf file that I used with libvirt and simplified it even further. Attached the simplified file and the output from ip addr. I tried other options: static, ra-stateless, and slaac worked OK (at least did not segfault). Both ra-only and ra-names segfaulted. The system is Fedora 18 which is more or less current. I also tried Fedora 17 but it only had 2.64 and 2.65 (or 2.59 which did not work at all). OK, ran it from the command line to get (a lot) more info. This is now in bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=920300 I have not really look at the info yet, just doing the collection. Gene # Mon 11 Mar 2013 12:57:16 EDT #strict-order #domain-needed #local=// #except-interface=lo #bind-dynamic interface=eth2 dhcp-range=fd00:ff:11:1::2,ra-only,64 #log-queries #log-dhcp 1: lo: LOOPBACK,UP,LOWER_UP mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: BROADCAST,MULTICAST,UP,LOWER_UP mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:51:a9:bc brd ff:ff:ff:ff:ff:ff inet 192.168.7.166/24 brd 192.168.7.255 scope global eth0 inet6 fd00:beef:10:7::1:37/128 scope global valid_lft forever preferred_lft forever inet6 fe80::5054:ff:fe51:a9bc/64 scope link valid_lft forever preferred_lft forever 3: eth1: BROADCAST,MULTICAST,UP,LOWER_UP mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:05:ad:c2 brd ff:ff:ff:ff:ff:ff inet6 fe80::5054:ff:fe05:adc2/64 scope link valid_lft forever preferred_lft forever 4: eth2: BROADCAST,MULTICAST,UP,LOWER_UP mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:31:55:fb brd ff:ff:ff:ff:ff:ff inet 192.168.223.1/24 brd 192.168.223.255 scope global eth2 inet6 fd00:ff:11:1::2/64 scope global valid_lft forever preferred_lft forever inet6 fe80::5054:ff:fe31:55fb/64 scope link valid_lft forever preferred_lft forever ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] ra-only segfault
On 11/03/13 18:29, Gene Czarcinski wrote: On 03/11/2013 12:44 PM, Gene Czarcinski wrote: On 03/11/2013 12:22 PM, Simon Kelley wrote: On 11/03/13 15:33, Gene Czarcinski wrote: Just happened so I am still collecting information but ... having a conf file with nothing much specified but: ... interface=eth2 dhcp-range=fd00:ff:11::2,ra-only ... results in a segfault I got this on real hardware with libvirt but have been able to duplicate it virtually. Attached are the syslog messages from the guests syslog. dnsmasq 2.65-4 on Fedora 18. Gene I just fed exactly those options into 2.65 as released by me, and it didn't crash, so we're going to have to pin this down a bit more. It would be too easy to be that repeatable. I will set something up to be simple and yet demonstrate the failure. More data. I took the dnsmasq.conf file that I used with libvirt and simplified it even further. Attached the simplified file and the output from ip addr. I tried other options: static, ra-stateless, and slaac worked OK (at least did not segfault). Both ra-only and ra-names segfaulted. The system is Fedora 18 which is more or less current. I also tried Fedora 17 but it only had 2.64 and 2.65 (or 2.59 which did not work at all). OK, ran it from the command line to get (a lot) more info. This is now in bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=920300 I have not really look at the info yet, just doing the collection. Gene Ok, this bug is long gone in the 2.66 releases, as the code has been completely re-written. The problem is that line 643 of src/dnsmasq.c uses daemon-dhcp_buff2 which is not allocated unless some DHCP service is configured. A minimal patch for RH would be something like daemon-dhcp_buff2=malloc(256); just before that line, workaround is to configure DHCP service as well as RA. Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
