* Is traceroute supposed to work in user mode networking (slirp) ? [not found] <CAEJNuHy+CqveTjiCxpjiLX-D=NczSveUSDSAZyz=D5F0XvL5QQ@mail.gmail.com> @ 2020-07-14 11:15 ` Ottavio Caruso 2020-07-19 2:50 ` Samuel Thibault 0 siblings, 1 reply; 6+ messages in thread From: Ottavio Caruso @ 2020-07-14 11:15 UTC (permalink / raw) To: qemu-devel [Originally asked on qemu-discuss but I didn't get any feedback. Thanks for your patience. Hi, I have enabled pinging from the guest changing the "net.ipv4.ping_group_range" on my Linux host. I can now ping any host using icmp. But I cannot get traceroute to work with standard udp from any of my guests. $ traceroute 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets 1 * * * 2 * * * 3 * * * 4 * * * [and so on] And if I use traceroute over icmp, I only get one hop shown: $ traceroute -I 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 60 byte packets 1 dns.google (8.8.8.8) 26.147 ms 27.88 ms 20.048 ms I have tested this with various guest OSes (OpenBSD, FreeBSD, NetBSD, Small Damn Linux). I've played around with various virtual interfaces but I have the same result. Any clues? Is this intended behaviour? Any workarounds that don't involve tap/tun/bridges? -- Ottavio Caruso ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Is traceroute supposed to work in user mode networking (slirp) ? 2020-07-14 11:15 ` Is traceroute supposed to work in user mode networking (slirp) ? Ottavio Caruso @ 2020-07-19 2:50 ` Samuel Thibault 2020-07-19 11:07 ` Ottavio Caruso 0 siblings, 1 reply; 6+ messages in thread From: Samuel Thibault @ 2020-07-19 2:50 UTC (permalink / raw) To: Ottavio Caruso; +Cc: qemu-devel Hello, Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit: > I cannot get traceroute to work with standard udp from any of my > guests. > > $ traceroute 8.8.8.8 > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets > 1 * * * That was because - libslirp was not forwarding the ttl value, thus always set to 64 hops - libslirp was not reporting icmp errors. I had a try at both, and that indeed seems to be fixing the issue: https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49 > Any clues? Is this intended behaviour? Any workarounds that don't > involve tap/tun/bridges? Not without updating libslirp with the abovementioned patches. Samuel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Is traceroute supposed to work in user mode networking (slirp) ? 2020-07-19 2:50 ` Samuel Thibault @ 2020-07-19 11:07 ` Ottavio Caruso 2020-07-19 11:16 ` Samuel Thibault 0 siblings, 1 reply; 6+ messages in thread From: Ottavio Caruso @ 2020-07-19 11:07 UTC (permalink / raw) To: Samuel Thibault, qemu-devel On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > Hello, > > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit: > > I cannot get traceroute to work with standard udp from any of my > > guests. > > > > $ traceroute 8.8.8.8 > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets > > 1 * * * > > That was because > > - libslirp was not forwarding the ttl value, thus always set to 64 hops > - libslirp was not reporting icmp errors. > > I had a try at both, and that indeed seems to be fixing the issue: > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49 > > > Any clues? Is this intended behaviour? Any workarounds that don't > > involve tap/tun/bridges? > > Not without updating libslirp with the abovementioned patches. Thanks Samuel. I've added a comment on the portal, but for the benefit of qemu-devel: Applying this patch on the latest qemu (5.0.90), does indeed implement traceroute, but it only reports one hop. I've tested this on a FreeBSD guest and a minimal DSL Linux guest: root@FreeBSD:/home/oc # uname -sr FreeBSD 12.1-RELEASE-p5 root@FreeBSD:/home/oc # traceroute google.com traceroute to google.com (216.58.206.110), 64 hops max, 40 byte packets 1 lhr25s14-in-f14.1e100.net (216.58.206.110) 20.555 ms 19.981 ms 19.042 ms root@FreeBSD:/home/oc # traceroute 1.1.1.1 traceroute to 1.1.1.1 (1.1.1.1), 64 hops max, 40 byte packets 1 one.one.one.one (1.1.1.1) 19.722 ms 19.171 ms 19.018 ms -- Ottavio Caruso ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Is traceroute supposed to work in user mode networking (slirp) ? 2020-07-19 11:07 ` Ottavio Caruso @ 2020-07-19 11:16 ` Samuel Thibault 2020-07-19 14:15 ` Ottavio Caruso 0 siblings, 1 reply; 6+ messages in thread From: Samuel Thibault @ 2020-07-19 11:16 UTC (permalink / raw) To: Ottavio Caruso; +Cc: qemu-devel Ottavio Caruso, le dim. 19 juil. 2020 12:07:21 +0100, a ecrit: > On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit: > > > I cannot get traceroute to work with standard udp from any of my > > > guests. > > > > > > $ traceroute 8.8.8.8 > > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets > > > 1 * * * > > > > That was because > > > > - libslirp was not forwarding the ttl value, thus always set to 64 hops > > - libslirp was not reporting icmp errors. > > > > I had a try at both, and that indeed seems to be fixing the issue: > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49 > > > > > Any clues? Is this intended behaviour? Any workarounds that don't > > > involve tap/tun/bridges? > > > > Not without updating libslirp with the abovementioned patches. > > Thanks Samuel. I've added a comment on the portal, but for the benefit > of qemu-devel: > > Applying this patch on the latest qemu (5.0.90), Did you also apply https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 ? Samuel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Is traceroute supposed to work in user mode networking (slirp) ? 2020-07-19 11:16 ` Samuel Thibault @ 2020-07-19 14:15 ` Ottavio Caruso 2020-07-19 14:58 ` Ottavio Caruso 0 siblings, 1 reply; 6+ messages in thread From: Ottavio Caruso @ 2020-07-19 14:15 UTC (permalink / raw) To: Samuel Thibault; +Cc: qemu-devel On Sun, 19 Jul 2020 at 12:16, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > Ottavio Caruso, le dim. 19 juil. 2020 12:07:21 +0100, a ecrit: > > On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit: > > > > I cannot get traceroute to work with standard udp from any of my > > > > guests. > > > > > > > > $ traceroute 8.8.8.8 > > > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets > > > > 1 * * * > > > > > > That was because > > > > > > - libslirp was not forwarding the ttl value, thus always set to 64 hops > > > - libslirp was not reporting icmp errors. > > > > > > I had a try at both, and that indeed seems to be fixing the issue: > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49 > > > > > > > Any clues? Is this intended behaviour? Any workarounds that don't > > > > involve tap/tun/bridges? > > > > > > Not without updating libslirp with the abovementioned patches. > > > > Thanks Samuel. I've added a comment on the portal, but for the benefit > > of qemu-devel: > > > > Applying this patch on the latest qemu (5.0.90), > > Did you also apply > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 ? No, because I thought that 49 would include 48. Let me give a try and come back. Updates on Gitlab. -- Ottavio Caruso ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Is traceroute supposed to work in user mode networking (slirp) ? 2020-07-19 14:15 ` Ottavio Caruso @ 2020-07-19 14:58 ` Ottavio Caruso 0 siblings, 0 replies; 6+ messages in thread From: Ottavio Caruso @ 2020-07-19 14:58 UTC (permalink / raw) To: qemu-devel; +Cc: Samuel Thibault On Sun, 19 Jul 2020 at 15:15, Ottavio Caruso <ottavio2006-usenet2012@yahoo.com> wrote: > > On Sun, 19 Jul 2020 at 12:16, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > > > Ottavio Caruso, le dim. 19 juil. 2020 12:07:21 +0100, a ecrit: > > > On Sun, 19 Jul 2020 at 03:50, Samuel Thibault <samuel.thibault@gnu.org> wrote: > > > > Ottavio Caruso, le mar. 14 juil. 2020 12:15:48 +0100, a ecrit: > > > > > I cannot get traceroute to work with standard udp from any of my > > > > > guests. > > > > > > > > > > $ traceroute 8.8.8.8 > > > > > traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 40 byte packets > > > > > 1 * * * > > > > > > > > That was because > > > > > > > > - libslirp was not forwarding the ttl value, thus always set to 64 hops > > > > - libslirp was not reporting icmp errors. > > > > > > > > I had a try at both, and that indeed seems to be fixing the issue: > > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 > > > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49 > > > > > > > > > Any clues? Is this intended behaviour? Any workarounds that don't > > > > > involve tap/tun/bridges? > > > > > > > > Not without updating libslirp with the abovementioned patches. > > > > > > Thanks Samuel. I've added a comment on the portal, but for the benefit > > > of qemu-devel: > > > > > > Applying this patch on the latest qemu (5.0.90), > > > > Did you also apply > > https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/48 ? > > No, because I thought that 49 would include 48. Let me give a try and > come back. Updates on Gitlab. Thanks. https://gitlab.freedesktop.org/slirp/libslirp/-/merge_requests/49#note_573654 When are we going to see this imported into qemu? I'm not extremely familiar with git modules. I assume this will one day be part of qemu upstream? -- Ottavio Caruso ^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] <CAEJNuHy+CqveTjiCxpjiLX-D=NczSveUSDSAZyz=D5F0XvL5QQ@mail.gmail.com>
2020-07-14 11:15 ` Is traceroute supposed to work in user mode networking (slirp) ? Ottavio Caruso
2020-07-19 2:50 ` Samuel Thibault
2020-07-19 11:07 ` Ottavio Caruso
2020-07-19 11:16 ` Samuel Thibault
2020-07-19 14:15 ` Ottavio Caruso
2020-07-19 14:58 ` Ottavio Caruso
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