Your message dated Tue, 01 Dec 2015 22:19:53 +0000 with message-id <[email protected]> and subject line Bug#231197: fixed in ifupdown 0.8 has caused the Debian Bug report #231197, regarding Please prevent ifup A -> hotplug -> ifup A deadlock to be marked as done.
This means that you claim that the problem has been dealt with. If this is not the case it is now your responsibility to reopen the Bug report if necessary, and/or fix the problem forthwith. (NB: If you are a system administrator and have no idea what this message is talking about, this may indicate a serious mail system misconfiguration somewhere. Please contact [email protected] immediately.) -- 231197: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=231197 Debian Bug Tracking System Contact [email protected] with problems
--- Begin Message ---Package: ifupdown Version: 0.6.4-4 Severity: important The use of ifupdown and network hotplug result in complete computer deadlock (need to press hard reset button). Background on network hotplug : There are basically two types of network interfaces, static (i.e. found at boot-time) and dynamic/removable/hotplug (that may appear/disapear at any time). Up to now, the only dynamic network interfaces were 16 bits Pcmcia network cards, which are managed by 'cardmgr' (included in the Pcmcia package). Cardmgr and ifupdown do interract properly, no problem there. Nowadays, a lot of 32 bits Bardbus network cards and USB network devices are being sold and supported by Linux. Those devices are managed exclusively through the hotplug system. Therefore, proper interoperation of ifupdown and hotplug is required to be able to support those devices. Problem : Let assume a standard laptop configuration with an integrated Ethernet port and a Pcmcia 32 bit 802.11g wireless cards. User configure the Ethernet port as a static interface (eth0). User must setup Hotplug to support the wireless interface (eth1). However, in such scenario, when the integrated Ethernet port is configured, the laptop will deadlock. Investigation : 1) At boot-up, /etc/init.d/networking call 'ifup -a'. 2) 'ifup -a' triggers 'modprobe eth0' (static Ethernet interface) 3) eth0 driver module loads 4) kernel send hotplug event for new interface 'eth0' 5) hotplug run 'net.agent' script 6) 'net.agent' calls 'ifup eth0' 7) 'ifup eth0' deadlock 8) kernel network layer deadlock (because hotplug doesn't return) Other way to reproduce the problem : B) Let's assume the user of the same laptop doesn't want the Ethernet interface to be brought up at boot, so doesn't include the 'auto' keyword in /etc/network/interfaces. At a later time, he decides to activate the interface manually running the command 'ifup eth0'. Deadlock. C) Let assume the user has a regular desktop with one Ethernet card and wthout knowing any better install the standard distribution of hotplug scripts, or an hypothetical 'Cardbus/USB network support' Debian package. Next time he reboots, deadlock. Fix : The fix is relatively simple : ifup must run in two phases. In the first phase, it read the config file and only 'modprobe' the relevant interfaces (cmd-line or -a), without aquiring any lock. In the second phase, it locks whatever needs to be locked and configure each interface if this interface is not already configured. It is my habit to send fully tested patches, not bug reports, but I could not find a usable source code for ifupdown (despite unpacking the source tar file on the package web page). You may want to fix that in the future. Therefore, I created a simple utility, 'ifloadall', that loads all modules specified in /etc/network/interfaces, and need to be run prior to 'ifup -a'. The source code is attached, along with a patch for the init scripts. I've tested this solution and it works properly on my PCs. Note that I don't consider this to be the "final" solution, just a proof of concept, because it doesn't address scenario (B), and it would need proper integration in ifupdown. Regards, Jean/* * Copyright Jean Tourrilhes <[email protected]> 2004 * This code is licensed under the GPL. */ #include <stdio.h> #include <string.h> #include <ctype.h> #include <stdlib.h> #define NET_CONFIG_FILE "/etc/network/interfaces" #define MODPROBE_CMD "/sbin/modprobe %s" /*------------------------------------------------------------------*/ /* * The main ! */ int main(int argc, char ** argv) { char buff[1024]; char * iface; char * end; char cmd[1100]; FILE * fh; /* Open config file */ fh = fopen(NET_CONFIG_FILE, "r"); if(fh == NULL) { fprintf(stderr, "%s: can't open file [%s] - abort !\n", argv[0], NET_CONFIG_FILE); return -1; } /* Read each config line */ while(fgets(buff, sizeof(buff), fh)) { /* Check for auto keyword, ignore when commented out */ if(!strncasecmp(buff, "auto ", 5)) { /* Skip keyword */ iface = buff + 5; /* Terminate at first comment */ end = strchr(iface, '#'); if(end != NULL) *end = '\0'; /* Loop on all interfaces given */ while(strlen(iface) > 0) { /* Look for end of interface name */ end = iface; while((*end != '\0') && (!isspace(*end))) end++; if(*end == '\0') end = NULL; else *end = '\0'; /* Do it ! */ fprintf(stderr, "%s: loading interface [%s]\n", argv[0], iface); sprintf(cmd, MODPROBE_CMD, buff + 5); system(cmd); /* Next interface */ if(end != NULL) { iface = end + 1; while(isspace(*iface)) iface++; } else /* Terminate */ *iface = '\0'; } } } /* Done */ fclose(fh); return 0; }diff -u -p /etc/init.d/networking-bad /etc/init.d/networking --- /etc/init.d/networking-bad Wed Feb 4 17:49:24 2004 +++ /etc/init.d/networking Wed Feb 4 17:49:54 2004 @@ -121,6 +121,7 @@ case "$1" in doopt ip_forward no echo -n "Configuring network interfaces: " + ifloadall ifup -a echo "done." ;;
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--- Begin Message ---Source: ifupdown Source-Version: 0.8 We believe that the bug you reported is fixed in the latest version of ifupdown, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to [email protected], and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Guus Sliepen <[email protected]> (supplier of updated ifupdown package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing [email protected]) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Format: 1.8 Date: Tue, 01 Dec 2015 23:09:54 +0100 Source: ifupdown Binary: ifupdown Architecture: source amd64 Version: 0.8 Distribution: unstable Urgency: medium Maintainer: Guus Sliepen <[email protected]> Changed-By: Guus Sliepen <[email protected]> Description: ifupdown - high level tools to configure network interfaces Closes: 231197 246771 762388 773539 791444 792896 799257 804978 806673 Changes: ifupdown (0.8) unstable; urgency=medium . [ Guus Sliepen ] * Add per-interface state files with locking. - Also detects and aborts on recursion. Closes: #231197 * Break up main() in smaller functions. * Return a non-zero exit code when (de)configuring an interface fails. Closes: 773539 * Add blank lines around examples in interfaces(5). Closes: #791444 * Enable RFC 4361 DDNS support when using dhclient, as suggested by Nicolas Cuissard. Closes: #799257 * Lock parent interface when configuration VLAN interfaces. * Apply fixes for issues found by AddressSanitizer and Clang Static Analyzer. * Drop the versioned dependency on initscripts. Closes: #804978 * Check for errors when running mapping scripts. Closes: #246771 * Wait for an IPv6 link-local address before starting a DHCPv6 client. Closes: 806673 * Add a systemd service file. . [ Andrew Shadura ] * Implement interface inheritance using the "inherits" keyword. . [ Jérémy Bobbio ] * Output methods in stable order when generating C code to make builds reproducible. Closes: #762388 . [ Javier Barroso ] * Fix detection of curlftpfs mounts. Closes: #792896 Checksums-Sha1: 5c2007559a0154927ebf3e07bd508e33374c880a 1516 ifupdown_0.8.dsc d97fbccfc71ac4f6e9c0bb608cfd966c3bc7450e 68032 ifupdown_0.8.tar.xz ed85f73df09e81561e2141f899ab9bb3dac37033 68950 ifupdown_0.8_amd64.deb Checksums-Sha256: 809c992402fa5011bab06484e4ad04db48c5bab6b28407b358d9b7be89bc9ccd 1516 ifupdown_0.8.dsc e11d8adfc5eadb564722b997b73dd4dcebc1ca13d30955a351ecbe8d3477497a 68032 ifupdown_0.8.tar.xz 8d6766f00c5638b48352940c212d80c23537de412991696e62ee6e076fb50d4d 68950 ifupdown_0.8_amd64.deb Files: 075d0f793175dfdd838fda4e528a3a1d 1516 admin important ifupdown_0.8.dsc bb17d8c37ef857e3423d25adea7a320f 68032 admin important ifupdown_0.8.tar.xz 8370af3b3831e2a01af5e976ecfb8a27 68950 admin important ifupdown_0.8_amd64.deb -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCAAGBQJWXhsMAAoJED9JDeuHHvn6ZBoP/iE7RxNhg0l6ix6J6Sz2NUPJ xorXt2hnlr/UPrXTyw3MSDX31mfz8PC0XcCKd0JVPH22e6OvoCS2qO3+PvawWOua vQGnNEu1HtWLtZ7XKQ3J8Rc7sgOqJEbioXk4wG0EFCf8kISxazN8W2sgLB/MFYEp l+QVcrjiRloFWLCKVW9YVNLARXAcPFRDf1Kqvlh21PdJ52n8FA5aA0CXwAJVRtAu zFEQl3EVpxZq0GrIR6t96qc2QGmKiQy1wu244jsEhbdqsINrY6o+x9568WQgJd4V fWMeogYxY+HJpdTZZ1RKq5YUwVuZfPmDQVSwzEK1W8M5j7r/iH6PEjtjirsstRB3 mJhI7BN8E8qnmjK1a+XVDwDzru8/Q62hhcULZLMjX+c2XLJ9eI1zvY2dix77e2yj 4hMAqw2gkG9HihryDQjTM/QP6RUW04zqb4QCEHDR8pBbFapZBnYeUoGkEj8rLZN9 nLrVRgdpRuJTCzpc9nxlPy4wjg9GCW5efGLrDWJyJkvgetg8fLKDqz+cYdFDwia+ ZH3lbGZYoXjX7Ri3CcmVZRenYs7NuV0BrOAOIZpAa9ur4Kg4hhEZTNACJ7YLAQQo djxOCEja+nZYDfzotSHlwKlS2i8I8rmWt/WQS+7gSpwms0IgAcHKYEPGER7RqwGG lcwjSk+FUuiYUutyffOz =Lgx1 -----END PGP SIGNATURE-----
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