From: Jeff D. <jd...@ka...> - 2000-10-05 00:29:26
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mac...@ed... said: > My machine at work (P600) seems to act still like it is missing > signals from the ttys/0 that I boot on. Appears as missed keystrokes. So, for example, you could type "abcdef" and on the screen would appear "abdf"? Does the shell act like it sees the missing characters? > Tcpdump on home box shows arp replies from UML, but for some reason > they are not picked up by the physical kernel. Can you see anything that the UML is doing wrong? > An attempted rsync to my work box of a few programs resulted in: Stack > overflowed onto current_task page In interrupt handler - not syncing > which resulted in me killing the linux processes. I need a stack trace of this. See the latest traffic on the devel list for how to get one. Jeff |
From: Jeff D. <jd...@ka...> - 2000-10-05 02:30:41
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macleajb@EDnet.NS.CA said: > > Does the shell act like it sees the missing characters? > I do not understand. If you type "abcdef" and see "abdf" on the screen, does bash say "abcdef: command not found" or "abdf: command not found"? > I even tried the tap0 approach. tcpdump on the physical sees the > traffic but the physical kernel/TCP/IP does not apply, act on it. I'd suspect something's going on with UML, but if traffic is disappearing into the host networking and disappearing, that doesn't give me much to go on. Jeff |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-05 09:33:17
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On Wed, 4 Oct 2000, Jeff Dike wrote: > macleajb@EDnet.NS.CA said: > > > Does the shell act like it sees the missing characters? > > I do not understand. > If you type "abcdef" and see "abdf" on the screen, does bash say "abcdef: > command not found" or "abdf: command not found"? It would be command not found... if it even acknowledges the enter ;). It makes logging in a very challenging experience :). > > I even tried the tap0 approach. tcpdump on the physical sees the > > traffic but the physical kernel/TCP/IP does not apply, act on it. > I'd suspect something's going on with UML, but if traffic is disappearing into > the host networking and disappearing, that doesn't give me much to go on. Agreed. And the fact that it works differently on a different machine is odd. 2 of the 3 machines at work were Mandrake installs, but one was RedHat like here at home, so I can't even suggest that :(. How can tcpdump see it, but the kernel not? I can understand it on interfaces where you inject it after the TCP/IP stack where only the wire/tapX gets to deal with it, but since it was working at work I don't see how it works differently here. I remember something in the tap devices where if you ran tcpdump on the tap, the data did not go any further than to see it on tcpdump, then if you stopped tcpdump, it would then go properly. I believe somebody added something about copying some struct in the kernel for each thing using the tap so that they all got to react and not just the first one in line. Likely not related, but mentioned anyhow :). cheers, JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: Jeff D. <jd...@ka...> - 2000-10-05 02:38:09
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ri...@co... said: > Btw, how "efficient" is networking between different UMLs within the > same box? ;) Probably depends on the interface you use. The old umn device uses the host kernel as the router. The new eth device uses a usermode daemon, but those packets also go through the kernel, so I'd guess there's slightly more overhead. Aside from the virtuality overhead, which is there on UML <-> anything networking, it's basically fancy IPC, which Linux ought to be pretty good at. Jeff |
From: Jeff D. <jd...@ka...> - 2000-10-05 15:31:01
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mac...@ed... said: > if it even acknowledges the enter ;). It makes logging in a very > challenging experience :). So, it happens so often you can't log in... Does it happen only on the main console? Have you checked it on a virtual console, the serial line, or in a telnet session? Can you tell me exactly how you're running UML? As for that networking thing, have you tried both interfaces to see if they both have the problem? Jeff |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-05 16:40:22
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On Thu, 5 Oct 2000, Jeff Dike wrote: > mac...@ed... said: > > if it even acknowledges the enter ;). It makes logging in a very > > challenging experience :). > So, it happens so often you can't log in... Yes, the password is hard to tell if you get a character or not :(. > Does it happen only on the main console? Have you checked it on a virtual > console, the serial line, or in a telnet session? Happens on ssh logins too. I believe it happend on other virtuals, but I have not tested that way lately. > Can you tell me exactly how you're running UML? In a directory I have a small root filesystem that was basically a boot disk with vi and ping added and some extra space to see if I could get apache on it :). I do not have experience with devfs so I mknod the ptys that ssh wants after the boot, but I know the problem was there before that :). I do the ./um_.... eth0 100 and then ./linux and up she comes. I have only one virtual screen, as I prefer to play via ssh so I can rsync stuff around. > As for that networking thing, have you tried both interfaces to see if they > both have the problem? You mean the umn method? Not from home because I did not have slip in the kernel. I will see about getting something there to test that. > Jeff > thanks again, JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: Jeff D. <jd...@ka...> - 2000-10-05 19:40:27
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macleajb@EDnet.NS.CA said: > Yes, the password is hard to tell if you get a character or not :(. I could see how that would really blow :-) > In a directory I have a small root filesystem that was basically a > boot disk with vi and ping added and some extra space to see if I > could get apache on it :). That makes it a little tough to reproduce it by doing exactly what you're doing. > You mean the umn method? Not from home because I did not have slip in > the kernel. Could that be the difference between home and work? slip is available as a module, so getting the umn device working shouldn't be hard. Jeff |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-05 20:52:36
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On Thu, 5 Oct 2000, Jeff Dike wrote: > macleajb@EDnet.NS.CA said: > > In a directory I have a small root filesystem that was basically a > > boot disk with vi and ping added and some extra space to see if I > > could get apache on it :). > That makes it a little tough to reproduce it by doing exactly what you're > doing. I can make the rootfs available if that would help, but I doubt it would :(. > > You mean the umn method? Not from home because I did not have slip in > > the kernel. > Could that be the difference between home and work? Sorry on my explaination. I am using um_eth_net_util at both sites. > slip is available as a module, so getting the umn device working shouldn't be > hard. I need it for my weird kernel, so I'll just have to compile one... Also, in a uml, um_eth_net_set says permission denied for /dev/ram0. Or atleast thats what I remember it saying :). But I figure I am just not booting things as I should :(. Later, JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 um_eth_net_set |
From: Jeff D. <jd...@ka...> - 2000-10-06 14:29:22
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mac...@ed... said: > Just ran umn this AM with 2.2.18pre11 as the slip physical host. > Worked just fine. I could contact physical, local subnet and remote > machines. > Tried um_eth_net again but still same problem. It can not ping > physical, can ping local subnet (and be connected to from same), and > can not ping remote networks. So the difference is between the umn and eth devices. Can you show exactly how you're doing the eth setup? Jeff |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-06 21:21:59
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On Fri, 6 Oct 2000, Jeff Dike wrote: > mac...@ed... said: > > Just ran umn this AM with 2.2.18pre11 as the slip physical host. > > Worked just fine. I could contact physical, local subnet and remote > > machines. > > Tried um_eth_net again but still same problem. It can not ping > > physical, can ping local subnet (and be connected to from same), and > > can not ping remote networks. > So the difference is between the umn and eth devices. Yes. And it only shows up on my home p166 machine. > Can you show exactly how you're doing the eth setup? A script does this to start up: killall um_eth_net_util sleep 1 echo Starting UML Network Device on ETH0 ./um_eth_net_util eth0 100 echo Starting Linux ./linux That inside linux does: ifconfig eth0 hw ether 0:0:10:2:4:1 ifconfig eth0 192.168.0.241 netmask 255.255.255.0 etc... > Jeff Is that what you were looking for? JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: Jeff D. <jd...@ka...> - 2000-10-07 00:16:55
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ma...@co... said: > Failed to set slip line discipline - errno = 1 Oh yeah, I forgot about that one. Some time after 2.2.5 (which is what I'm running) someone tightened up the security on slip so that you need to be root in order to set the slip line discipline on a tty. For later 2.2 kernels, um_ifconfig isn't enough. The suid helper also needs to take the fd to the tty from uml and set up slip on it. Jeff |
From: Jeff D. <jd...@ka...> - 2000-10-07 20:34:57
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epa...@up... said: > for many apps simply proxying at the socket level from the UML kernel > to the host kernel would be completely sufficent - imagine someone > running a sandboxed app, or (when UML gets ported to say FreeBSD) > running a Linux app that opens a non-priviliged socket up to the > network. There doesn't seem to be any theoretical reason why that > shouldn't be possible. Can a socket be made to look enough like a real network interface to be useful? All network proggies do the bind/listen/accept/connect thing, which sends you into the network layer. At the device layer all you see are packets which need to be sent off somewhere. I don't see how those can be sent to a socket - they need to be sent via a device in the host. So a device driver doesn't seem like it would work. Are there other layers in the network subsystem that have the hooks to plug something else in that would work? It would be nice to drop the suid helper, but I don't see a way to do it. Jeff |
From: Rik v. R. <ri...@co...> - 2000-10-05 00:37:43
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On Wed, 4 Oct 2000, Jeff Dike wrote: > mac...@ed... said: > > My machine at work (P600) seems to act still like it is missing > > signals from the ttys/0 that I boot on. Appears as missed keystrokes. > > So, for example, you could type "abcdef" and on the screen would appear "abdf"? > > Does the shell act like it sees the missing characters? I've seen this happen when I tested UML yesterday ... [UML networking] Hmmm, I will need to play with this. Btw, how "efficient" is networking between different UMLs within the same box? ;) regards, Rik -- "What you're running that piece of shit Gnome?!?!" -- Miguel de Icaza, UKUUG 2000 http://www.conectiva.com/ http://www.surriel.com/ |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-05 00:45:21
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On Wed, 4 Oct 2000, Rik van Riel wrote: > On Wed, 4 Oct 2000, Jeff Dike wrote: > > mac...@ed... said: > > > My machine at work (P600) seems to act still like it is missing > > > signals from the ttys/0 that I boot on. Appears as missed keystrokes. > > So, for example, you could type "abcdef" and on the screen would appear "abdf"? > > Does the shell act like it sees the missing characters? > I've seen this happen when I tested UML yesterday ... So far on all boxes at work I've seen it and on all the kernels I tried, yet at home, it has not appeared, or else I just miss it :). > [UML networking] > Hmmm, I will need to play with this. Btw, how "efficient" > is networking between different UMLs within the same box? ;) Well, bursty would be a word. Sometimes real good, other times it seems to stall. It's like signals are not getting through (like the keyboard I guess :). > regards, > Rik take care, JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-05 00:41:59
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On Wed, 4 Oct 2000, Jeff Dike wrote: > mac...@ed... said: > > My machine at work (P600) seems to act still like it is missing > > signals from the ttys/0 that I boot on. Appears as missed keystrokes. > So, for example, you could type "abcdef" and on the screen would appear "abdf"? Yes. In its worse state you can type for a while and nothing, then suddenly it begins again, but misses all the in between strokes. > Does the shell act like it sees the missing characters? I do not understand. The modem lights flicker (I'm at home connecting to work), but I see nothing in the screen to suggest it is getting anything. > > Tcpdump on home box shows arp replies from UML, but for some reason > > they are not picked up by the physical kernel. > Can you see anything that the UML is doing wrong? Not by my looking. I can basically get at all boxes other than the physical box that are on the local network (no need for forwarding). Yet forwarding is on in both physical and UML, and I am already using this box as a gateway for other traffic. I tried multiple ip's with no luck. I even tried the tap0 approach. tcpdump on the physical sees the traffic but the physical kernel/TCP/IP does not apply, act on it. Even when I manually add the arp into the table, it just acts as if there is no traffic for it to see. > > An attempted rsync to my work box of a few programs resulted in: Stack > > overflowed onto current_task page In interrupt handler - not syncing > > which resulted in me killing the linux processes. > I need a stack trace of this. See the latest traffic on the devel list for > how to get one. > Jeff Saw about 6 messages. I will look into getting that done. Thanks, JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-06 09:42:00
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Hi Jeff et al, Just ran umn this AM with 2.2.18pre11 as the slip physical host. Worked just fine. I could contact physical, local subnet and remote machines. Tried um_eth_net again but still same problem. It can not ping physical, can ping local subnet (and be connected to from same), and can not ping remote networks. JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: Matt C. <ma...@co...> - 2000-10-06 20:54:47
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James MacLean wrote: > Just ran umn this AM with 2.2.18pre11 as the slip physical host. Worked > just fine. I could contact physical, local subnet and remote machines. Are you running UML as a non-root user when using umn? I am trying to do so, but have only had success when running UML as root. - Matt |
From: James M. <macleajb@EDnet.NS.CA> - 2000-10-06 21:30:46
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On Fri, 6 Oct 2000, Matt Clay wrote: > James MacLean wrote: > > Just ran umn this AM with 2.2.18pre11 as the slip physical host. Worked > > just fine. I could contact physical, local subnet and remote machines. > Are you running UML as a non-root user when using umn? I am trying to > do so, but have only had success when running UML as root. Yes. All testing to date is being done as root. > - Matt JES -- James B. MacLean mac...@ed... Department of Education http://www.ednet.ns.ca/~macleajb Nova Scotia, Canada B3M 4B2 |
From: Matt C. <ma...@co...> - 2000-10-06 21:37:39
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James MacLean wrote: > > > Just ran umn this AM with 2.2.18pre11 as the slip physical host. Worked > > > just fine. I could contact physical, local subnet and remote machines. > > Are you running UML as a non-root user when using umn? I am trying to > > do so, but have only had success when running UML as root. > Yes. All testing to date is being done as root. Is there any way to setup networking without running UML as root? - Matt |
From: Jeff D. <jd...@ka...> - 2000-10-06 22:05:30
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ma...@co... said: > Is there any way to setup networking without running UML as root? UML can be running as a normal user, but you do need a suid helper. With the umn device, just put a suid root ifconfig somewhere in your path. With the eth device, you run um_eth_net_util as root if you want access to the host networking. If you only want to network UMLs, then that doesn't even need to run as root. Jeff |
From: Matt C. <ma...@co...> - 2000-10-06 22:16:42
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Jeff Dike wrote: > UML can be running as a normal user, but you do need a suid helper. With the > umn device, just put a suid root ifconfig somewhere in your path. I've tried making a suid copy of ifconfig in my path on my host system, called um_ifconfig, which runs when I use ifconfig in UML. It doesn't fix the problem though. Here's what I get (if running UML as root, this same setup works just fine): Going multiuser... Configuring eth0 as 10.0.0.101... Failed to set slip line discipline - errno = 1 Couldn't set slip encapsulation - errno = 22 SIOCSIFADDR: No such device sl-1: unknown interface: No such device SIOCSIFDSTADDR: No such device sl-1: unknown interface: No such device sl-1: unknown interface: No such device um_ifconfig failed SIOCSIFHWADDR: Operation not permitted Failed to initialize network! Activating IPv4 packet forwarding... > With the eth device, you run um_eth_net_util as root if you want access to the > host networking. If you only want to network UMLs, then that doesn't even > need to run as root. I'll give this a try, thanks. - Matt |
From: Matt C. <ma...@co...> - 2000-10-06 23:10:37
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Jeff Dike wrote: > With the eth device, you run um_eth_net_util as root if you want access to the > host networking. If you only want to network UMLs, then that doesn't even > need to run as root. Finally, I got this working! Now I've got a non-root UML running, with access to the rest of my network. Thanks for the help. - Matt |
From: Erik P. <epa...@up...> - 2000-10-07 19:17:42
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On Fri, Oct 06, 2000 at 06:12:26PM -0500, Jeff Dike wrote: > ma...@co... said: > > Is there any way to setup networking without running UML as root? > > UML can be running as a normal user, but you do need a suid helper. With the > umn device, just put a suid root ifconfig somewhere in your path. > > With the eth device, you run um_eth_net_util as root if you want access to the > host networking. If you only want to network UMLs, then that doesn't even > need to run as root. This requirement of even having a suid is kind of a bummer - for many apps simply proxying at the socket level from the UML kernel to the host kernel would be completely sufficent - imagine someone running a sandboxed app, or (when UML gets ported to say FreeBSD) running a Linux app that opens a non-priviliged socket up to the network. There doesn't seem to be any theoretical reason why that shouldn't be possible. Many sysadmins (myself included) get very nervous when users ask for a suid helper. -Erik > > Jeff > > > _______________________________________________ > User-mode-linux-user mailing list > Use...@li... > http://lists.sourceforge.net/mailman/listinfo/user-mode-linux-user |
From: Jeff D. <jd...@ka...> - 2000-10-07 22:23:28
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epa...@up... said: > Many sysadmins (myself included) get very nervous when users ask for a > suid helper. There's another possibility. The eth daemon can be made to communicate with its peers on other boxes (which is a good idea in its own right), and you could set up a virtual network that has non-privileged daemons, except for one running as root on a machine that no one cares about. That one would be the gateway to the outside world for all the others. I think that most sysadmins would have no trouble finding an old box that could be dedicated as the UML gateway. If it got rooted through the eth daemon, that doesn't pose any danger to anything else. Jeff |
From: Chris E. <cem...@ch...> - 2000-10-09 11:56:12
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On Saturday, 7 Oct 2000, Jeff Dike wrote: > epa...@up... said: > > Many sysadmins (myself included) get very nervous when users ask > > for a suid helper. > > There's another possibility. The eth daemon can be made to > communicate with its peers on other boxes (which is a good idea in > its own right), and you could set up a virtual network that has > non-privileged daemons, except for one running as root on a machine > that no one cares about. That one would be the gateway to the > outside world for all the others. I think it would still be nice to avoid root altogether where possible. Seems to me that something like slirp (http://slirp.sourceforge.net/) could be useful here. Chris -- Chris Emerson, obsessed Cambridge juggler E-mail: cem...@ch... Web page: http://www.chiark.greenend.org.uk/~cemerson/ |