[libvirt] [PATCH] lxc: do not require 'ifconfig' or 'ipconfig' in container
Currently, the lxc implementation invokes 'ip' and 'ifconfig' commands inside a container using 'virRun'. That has the side effect of requiring those commands to be present and to function in a manner consistent with the usage. Some small roots (such as ttylinux) may not have 'ip' or 'ifconfig'. This patch replaces the use of these commands with usage of netdevice. The result is that lxc containers do not have to implement those commands, and lxc in libvirt is only dependent on the netdevice interface. I've tested this patch locally against the ubuntu libvirt version enough to verify its generally sane. I attempted to build upstream today, but failed with: /usr/bin/ld: ../src/.libs/libvirt_driver_qemu.a(libvirt_driver_qemu_la-qemu_domain.o): undefined reference to symbol 'xmlXPathRegisterNs@@LIBXML2_2.4.30 Thats probably a local issue only, but I wanted to get this patch up and see what others thought of it. This is ubuntu bug https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/828211 . diff --git a/src/lxc/veth.c b/src/lxc/veth.c index 34cb804..c24df91 100644 --- a/src/lxc/veth.c +++ b/src/lxc/veth.c @@ -12,8 +12,11 @@ #include <config.h> +#include <linux/sockios.h> +#include <net/if.h> #include <string.h> #include <stdio.h> +#include <sys/ioctl.h> #include <sys/types.h> #include <sys/wait.h> @@ -186,41 +189,49 @@ int vethDelete(const char *veth) * @veth: name of veth device * @upOrDown: 0 => down, 1 => up * - * Enables a veth device using the ifconfig command. A NULL inetAddress - * will cause it to be left off the command line. + * Enables a veth device using SIOCSIFFLAGS * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure, with errno set */ int vethInterfaceUpOrDown(const char* veth, int upOrDown) { - int rc; - const char *argv[] = {"ifconfig", veth, NULL, NULL}; - int cmdResult = 0; + struct ifreq ifr; + int fd, ret; - if (0 == upOrDown) - argv[2] = "down"; - else - argv[2] = "up"; + if ((fd = socket(PF_PACKET, SOCK_DGRAM, 0)) == -1) + return(-1); - rc = virRun(argv, &cmdResult); + memset(&ifr, 0, sizeof(struct ifreq)); - if (rc != 0 || - (WIFEXITED(cmdResult) && WEXITSTATUS(cmdResult) != 0)) { - if (0 == upOrDown) + if (virStrcpyStatic(ifr.ifr_name, veth) == NULL) { + errno = EINVAL; + return -1; + } + + if ((ret = ioctl(fd, SIOCGIFFLAGS, &ifr)) == 0) { + if (upOrDown) + ifr.ifr_flags |= IFF_UP; + else + ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING); + + ret = ioctl(fd, SIOCSIFFLAGS, &ifr); + } + + close(fd); + if (ret == -1) + if (upOrDown == 0) /* * Prevent overwriting an error log which may be set * where an actual failure occurs. */ - VIR_DEBUG("Failed to disable '%s' (%d)", - veth, WEXITSTATUS(cmdResult)); + VIR_DEBUG("Failed to disable '%s'", veth); else vethError(VIR_ERR_INTERNAL_ERROR, - _("Failed to enable '%s' (%d)"), - veth, WEXITSTATUS(cmdResult)); - rc = -1; - } + _("Failed to enable '%s'"), veth); + else + ret = 0; - return rc; + return(ret); } /** @@ -279,17 +290,29 @@ int setMacAddr(const char* iface, const char* macaddr) * @iface: name of device * @new: new name of @iface * - * Changes the name of the given device with the - * given new name using this command: - * ip link set @iface name @new + * Changes the name of the given device. * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure with errno set. */ int setInterfaceName(const char* iface, const char* new) { - const char *argv[] = { - "ip", "link", "set", iface, "name", new, NULL - }; + struct ifreq ifr; + int fd = socket(PF_PACKET, SOCK_DGRAM, 0); - return virRun(argv, NULL); + memset(&ifr, 0, sizeof(struct ifreq)); + + if (virStrcpyStatic(ifr.ifr_name, iface) == NULL) { + errno = EINVAL; + return -1; + } + + if (virStrcpyStatic(ifr.ifr_newname, new) == NULL) { + errno = EINVAL; + return -1; + } + + if (ioctl(fd, SIOCSIFNAME, &ifr)) + return -1; + + return 0; }
Quoting Scott Moser (smoser@ubuntu.com):
Currently, the lxc implementation invokes 'ip' and 'ifconfig' commands inside a container using 'virRun'. That has the side effect of requiring those commands to be present and to function in a manner consistent with the usage. Some small roots (such as ttylinux) may not have 'ip' or 'ifconfig'.
This patch replaces the use of these commands with usage of netdevice. The result is that lxc containers do not have to implement those commands, and lxc in libvirt is only dependent on the netdevice interface.
Requiring fewer tools in the container seems like a very good thing, especially when trying to create a tiny busybox-based container. thanks, -serge
I've tested this patch locally against the ubuntu libvirt version enough to verify its generally sane. I attempted to build upstream today, but failed with: /usr/bin/ld: ../src/.libs/libvirt_driver_qemu.a(libvirt_driver_qemu_la-qemu_domain.o): undefined reference to symbol 'xmlXPathRegisterNs@@LIBXML2_2.4.30
Thats probably a local issue only, but I wanted to get this patch up and see what others thought of it. This is ubuntu bug https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/828211 .
diff --git a/src/lxc/veth.c b/src/lxc/veth.c index 34cb804..c24df91 100644 --- a/src/lxc/veth.c +++ b/src/lxc/veth.c @@ -12,8 +12,11 @@
#include <config.h>
+#include <linux/sockios.h> +#include <net/if.h> #include <string.h> #include <stdio.h> +#include <sys/ioctl.h> #include <sys/types.h> #include <sys/wait.h>
@@ -186,41 +189,49 @@ int vethDelete(const char *veth) * @veth: name of veth device * @upOrDown: 0 => down, 1 => up * - * Enables a veth device using the ifconfig command. A NULL inetAddress - * will cause it to be left off the command line. + * Enables a veth device using SIOCSIFFLAGS * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure, with errno set */ int vethInterfaceUpOrDown(const char* veth, int upOrDown) { - int rc; - const char *argv[] = {"ifconfig", veth, NULL, NULL}; - int cmdResult = 0; + struct ifreq ifr; + int fd, ret;
- if (0 == upOrDown) - argv[2] = "down"; - else - argv[2] = "up"; + if ((fd = socket(PF_PACKET, SOCK_DGRAM, 0)) == -1) + return(-1);
- rc = virRun(argv, &cmdResult); + memset(&ifr, 0, sizeof(struct ifreq));
- if (rc != 0 || - (WIFEXITED(cmdResult) && WEXITSTATUS(cmdResult) != 0)) { - if (0 == upOrDown) + if (virStrcpyStatic(ifr.ifr_name, veth) == NULL) { + errno = EINVAL; + return -1; + } + + if ((ret = ioctl(fd, SIOCGIFFLAGS, &ifr)) == 0) { + if (upOrDown) + ifr.ifr_flags |= IFF_UP; + else + ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING); + + ret = ioctl(fd, SIOCSIFFLAGS, &ifr); + } + + close(fd); + if (ret == -1) + if (upOrDown == 0) /* * Prevent overwriting an error log which may be set * where an actual failure occurs. */ - VIR_DEBUG("Failed to disable '%s' (%d)", - veth, WEXITSTATUS(cmdResult)); + VIR_DEBUG("Failed to disable '%s'", veth); else vethError(VIR_ERR_INTERNAL_ERROR, - _("Failed to enable '%s' (%d)"), - veth, WEXITSTATUS(cmdResult)); - rc = -1; - } + _("Failed to enable '%s'"), veth); + else + ret = 0;
- return rc; + return(ret); }
/** @@ -279,17 +290,29 @@ int setMacAddr(const char* iface, const char* macaddr) * @iface: name of device * @new: new name of @iface * - * Changes the name of the given device with the - * given new name using this command: - * ip link set @iface name @new + * Changes the name of the given device. * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure with errno set. */ int setInterfaceName(const char* iface, const char* new) { - const char *argv[] = { - "ip", "link", "set", iface, "name", new, NULL - }; + struct ifreq ifr; + int fd = socket(PF_PACKET, SOCK_DGRAM, 0);
- return virRun(argv, NULL); + memset(&ifr, 0, sizeof(struct ifreq)); + + if (virStrcpyStatic(ifr.ifr_name, iface) == NULL) { + errno = EINVAL; + return -1; + } + + if (virStrcpyStatic(ifr.ifr_newname, new) == NULL) { + errno = EINVAL; + return -1; + } + + if (ioctl(fd, SIOCSIFNAME, &ifr)) + return -1; + + return 0; }
On Wed, Aug 31, 2011 at 02:02:10PM -0500, Serge Hallyn wrote:
Quoting Scott Moser (smoser@ubuntu.com):
Currently, the lxc implementation invokes 'ip' and 'ifconfig' commands inside a container using 'virRun'. That has the side effect of requiring those commands to be present and to function in a manner consistent with the usage. Some small roots (such as ttylinux) may not have 'ip' or 'ifconfig'.
This patch replaces the use of these commands with usage of netdevice. The result is that lxc containers do not have to implement those commands, and lxc in libvirt is only dependent on the netdevice interface.
Requiring fewer tools in the container seems like a very good thing, especially when trying to create a tiny busybox-based container.
Yep, and we already directly do this kind of thing elsewhere in libvirt without external tools, so there is precedent.
I've tested this patch locally against the ubuntu libvirt version enough to verify its generally sane. I attempted to build upstream today, but failed with: /usr/bin/ld: ../src/.libs/libvirt_driver_qemu.a(libvirt_driver_qemu_la-qemu_domain.o): undefined reference to symbol 'xmlXPathRegisterNs@@LIBXML2_2.4.30
Thats probably a local issue only, but I wanted to get this patch up and see what others thought of it. This is ubuntu bug https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/828211 .
diff --git a/src/lxc/veth.c b/src/lxc/veth.c index 34cb804..c24df91 100644 --- a/src/lxc/veth.c +++ b/src/lxc/veth.c @@ -12,8 +12,11 @@
#include <config.h>
+#include <linux/sockios.h> +#include <net/if.h> #include <string.h> #include <stdio.h> +#include <sys/ioctl.h> #include <sys/types.h> #include <sys/wait.h>
@@ -186,41 +189,49 @@ int vethDelete(const char *veth) * @veth: name of veth device * @upOrDown: 0 => down, 1 => up * - * Enables a veth device using the ifconfig command. A NULL inetAddress - * will cause it to be left off the command line. + * Enables a veth device using SIOCSIFFLAGS * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure, with errno set */ int vethInterfaceUpOrDown(const char* veth, int upOrDown) { - int rc; - const char *argv[] = {"ifconfig", veth, NULL, NULL}; - int cmdResult = 0; + struct ifreq ifr; + int fd, ret;
- if (0 == upOrDown) - argv[2] = "down"; - else - argv[2] = "up"; + if ((fd = socket(PF_PACKET, SOCK_DGRAM, 0)) == -1) + return(-1);
- rc = virRun(argv, &cmdResult); + memset(&ifr, 0, sizeof(struct ifreq));
- if (rc != 0 || - (WIFEXITED(cmdResult) && WEXITSTATUS(cmdResult) != 0)) { - if (0 == upOrDown) + if (virStrcpyStatic(ifr.ifr_name, veth) == NULL) { + errno = EINVAL; + return -1; + } + + if ((ret = ioctl(fd, SIOCGIFFLAGS, &ifr)) == 0) { + if (upOrDown) + ifr.ifr_flags |= IFF_UP; + else + ifr.ifr_flags &= ~(IFF_UP | IFF_RUNNING); + + ret = ioctl(fd, SIOCSIFFLAGS, &ifr); + } + + close(fd); + if (ret == -1) + if (upOrDown == 0) /* * Prevent overwriting an error log which may be set * where an actual failure occurs. */ - VIR_DEBUG("Failed to disable '%s' (%d)", - veth, WEXITSTATUS(cmdResult)); + VIR_DEBUG("Failed to disable '%s'", veth); else vethError(VIR_ERR_INTERNAL_ERROR, - _("Failed to enable '%s' (%d)"), - veth, WEXITSTATUS(cmdResult)); - rc = -1; - } + _("Failed to enable '%s'"), veth); + else + ret = 0;
- return rc; + return(ret); }
/** @@ -279,17 +290,29 @@ int setMacAddr(const char* iface, const char* macaddr) * @iface: name of device * @new: new name of @iface * - * Changes the name of the given device with the - * given new name using this command: - * ip link set @iface name @new + * Changes the name of the given device. * - * Returns 0 on success or -1 in case of error + * Returns 0 on success, -1 on failure with errno set. */ int setInterfaceName(const char* iface, const char* new) { - const char *argv[] = { - "ip", "link", "set", iface, "name", new, NULL - }; + struct ifreq ifr; + int fd = socket(PF_PACKET, SOCK_DGRAM, 0);
- return virRun(argv, NULL); + memset(&ifr, 0, sizeof(struct ifreq)); + + if (virStrcpyStatic(ifr.ifr_name, iface) == NULL) { + errno = EINVAL; + return -1; + } + + if (virStrcpyStatic(ifr.ifr_newname, new) == NULL) { + errno = EINVAL; + return -1; + } + + if (ioctl(fd, SIOCSIFNAME, &ifr)) + return -1; + + return 0; }
ACK Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On 09/01/2011 03:02 AM, Daniel P. Berrange wrote:
On Wed, Aug 31, 2011 at 02:02:10PM -0500, Serge Hallyn wrote:
Quoting Scott Moser (smoser@ubuntu.com):
Currently, the lxc implementation invokes 'ip' and 'ifconfig' commands inside a container using 'virRun'. That has the side effect of requiring those commands to be present and to function in a manner consistent with the usage. Some small roots (such as ttylinux) may not have 'ip' or 'ifconfig'.
ACK
+ + close(fd);
That fails 'make syntax-check'. Pushed as modified: diff --git i/src/lxc/veth.c w/src/lxc/veth.c index c24df91..e4db65c 100644 --- i/src/lxc/veth.c +++ w/src/lxc/veth.c @@ -1,7 +1,7 @@ /* * veth.c: Tools for managing veth pairs * - * Copyright (C) 2010 Red Hat, Inc. + * Copyright (C) 2010-2011 Red Hat, Inc. * Copyright IBM Corp. 2008 * * See COPYING.LIB for the License of this software @@ -26,6 +26,7 @@ #include "memory.h" #include "command.h" #include "virterror_internal.h" +#include "virfile.h" #define VIR_FROM_THIS VIR_FROM_LXC @@ -217,7 +218,7 @@ int vethInterfaceUpOrDown(const char* veth, int upOrDown) ret = ioctl(fd, SIOCSIFFLAGS, &ifr); } - close(fd); + VIR_FORCE_CLOSE(fd); if (ret == -1) if (upOrDown == 0) /* -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org
participants (4)
-
Daniel P. Berrange -
Eric Blake -
Scott Moser -
Serge Hallyn