Public bug reported: Using the Trusty GA kernel, we found that when capturing network packets with libpcap using a loop
pcap_dispatch(handle, -1, dispatcher, NULL); select(fd + 1, & fd_selected, 0, 0, &timeval); where timeval = 2s, packets are missed if they arrive at low rates. I have a small test capture program (attached) which shows pings not being captured on an otherwise idle network connection. The problem does not occur on later (e.g. LTS Enablement Xenial) kernels. We believe the following fixes the cause: https://github.com/torvalds/linux/commit/da413eec729dae5dcb150e2eb34c5e7e5e4e1b49 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-generic 3.13.0.121.131 ProcVersionSignature: Ubuntu 3.13.0-121.170-generic 3.13.11-ckt39 Uname: Linux 3.13.0-121-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.23 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: jim 2070 F.... pulseaudio CurrentDesktop: Unity Date: Tue Jun 27 11:32:11 2017 HibernationDevice: RESUME=UUID=532db246-2b7f-45e1-a3f1-18720bbb7349 InstallationDate: Installed on 2016-11-03 (235 days ago) InstallationMedia: Ubuntu 14.04.5 LTS "Trusty Tahr" - Release amd64 (20160803) IwConfig: eth0 no wireless extensions. lo no wireless extensions. Lsusb: Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: innotek GmbH VirtualBox ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-121-generic root=UUID=392afc20-cb81-4990-94f1-026ef649561f ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-121-generic N/A linux-backports-modules-3.13.0-121-generic N/A linux-firmware 1.127.23 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/01/2006 dmi.bios.vendor: innotek GmbH dmi.bios.version: VirtualBox dmi.board.name: VirtualBox dmi.board.vendor: Oracle Corporation dmi.board.version: 1.2 dmi.chassis.type: 1 dmi.chassis.vendor: Oracle Corporation dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr: dmi.product.name: VirtualBox dmi.product.version: 1.2 dmi.sys.vendor: innotek GmbH ** Affects: linux (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: amd64 apport-bug trusty -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1700746 Title: select() on network device loses packets at low data rates Status in linux package in Ubuntu: Confirmed Bug description: Using the Trusty GA kernel, we found that when capturing network packets with libpcap using a loop pcap_dispatch(handle, -1, dispatcher, NULL); select(fd + 1, & fd_selected, 0, 0, &timeval); where timeval = 2s, packets are missed if they arrive at low rates. I have a small test capture program (attached) which shows pings not being captured on an otherwise idle network connection. The problem does not occur on later (e.g. LTS Enablement Xenial) kernels. We believe the following fixes the cause: https://github.com/torvalds/linux/commit/da413eec729dae5dcb150e2eb34c5e7e5e4e1b49 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-generic 3.13.0.121.131 ProcVersionSignature: Ubuntu 3.13.0-121.170-generic 3.13.11-ckt39 Uname: Linux 3.13.0-121-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.23 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: jim 2070 F.... pulseaudio CurrentDesktop: Unity Date: Tue Jun 27 11:32:11 2017 HibernationDevice: RESUME=UUID=532db246-2b7f-45e1-a3f1-18720bbb7349 InstallationDate: Installed on 2016-11-03 (235 days ago) InstallationMedia: Ubuntu 14.04.5 LTS "Trusty Tahr" - Release amd64 (20160803) IwConfig: eth0 no wireless extensions. lo no wireless extensions. Lsusb: Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: innotek GmbH VirtualBox ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-121-generic root=UUID=392afc20-cb81-4990-94f1-026ef649561f ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.13.0-121-generic N/A linux-backports-modules-3.13.0-121-generic N/A linux-firmware 1.127.23 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/01/2006 dmi.bios.vendor: innotek GmbH dmi.bios.version: VirtualBox dmi.board.name: VirtualBox dmi.board.vendor: Oracle Corporation dmi.board.version: 1.2 dmi.chassis.type: 1 dmi.chassis.vendor: Oracle Corporation dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:rvnOracleCorporation:rnVirtualBox:rvr1.2:cvnOracleCorporation:ct1:cvr: dmi.product.name: VirtualBox dmi.product.version: 1.2 dmi.sys.vendor: innotek GmbH To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1700746/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp