From 69c79d3c32ff4d6a572ee1cdec248b27df1fb6ca Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 13 Feb 2014 18:47:20 +0100 Subject: [PATCH] nspawn: add new --network-veth switch to add a virtual ethernet link to the host --- man/systemd-nspawn.xml | 127 +++++++++++++++++++-------------- src/nspawn/nspawn.c | 155 ++++++++++++++++++++++++++++++++++++----- 2 files changed, 213 insertions(+), 69 deletions(-) diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml index ffd707092..d6f2d11dc 100644 --- a/man/systemd-nspawn.xml +++ b/man/systemd-nspawn.xml @@ -173,6 +173,17 @@ and exits. + + + + + Turns off any status + output by the tool itself. When this + switch is used, then the only output + by nspawn will be the console output + of the container OS itself. + + @@ -228,37 +239,6 @@ container is used. - - - - Make the container - part of the specified slice, instead - of the - machine.slice. - - - - - - - - Sets the SELinux - security context to be used to label - processes in the container. - - - - - - - - Sets the SELinux security - context to be used to label files in - the virtual API file systems in the - container. - - - @@ -270,16 +250,28 @@ + + + + Make the container + part of the specified slice, instead + of the default + machine.slice. + + + - Turn off networking in - the container. This makes all network - interfaces unavailable in the - container, with the exception of the - loopback device and those specified - with - . If + Disconnect networking + of the container from the host. This + makes all network interfaces + unavailable in the container, with the + exception of the loopback device and + those specified with + + and configured ith + . If this option is specified the CAP_NET_ADMIN capability will be added to the set of capabilities the @@ -308,11 +300,43 @@ - + + + Create a virtual + ethernet link between host and + container. The host side of the + ethernet link will be available as + network interface named after the + container's name (as specified with + ), prefixed + with ve-. The + container side of the the ethernet + link will be named + host0. Note that + + implies + . + - Mount the root file - system read-only for the - container. + + + + + Sets the SELinux + security context to be used to label + processes in the container. + + + + + + + + Sets the SELinux security + context to be used to label files in + the virtual API file systems in the + container. + @@ -405,6 +429,14 @@ . + + + + Mount the root file + system read-only for the + container. + + @@ -439,17 +471,6 @@ more than once. - - - - - Turns off any status - output by the tool itself. When this - switch is used, then the only output - by nspawn will be the console output - of the container OS itself. - - diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index abcee3fb9..b4c5a5494 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -43,6 +43,7 @@ #include #include #include +#include #ifdef HAVE_SELINUX #include @@ -128,6 +129,7 @@ static bool arg_share_system = false; static bool arg_register = true; static bool arg_keep_unit = false; static char **arg_network_interfaces = NULL; +static bool arg_network_veth = false; static int help(void) { @@ -135,36 +137,39 @@ static int help(void) { "Spawn a minimal namespace container for debugging, testing and building.\n\n" " -h --help Show this help\n" " --version Print version string\n" + " -q --quiet Do not show status information\n" " -D --directory=NAME Root directory for the container\n" " -b --boot Boot up full system (i.e. invoke init)\n" " -u --user=USER Run the command under specified user or uid\n" - " --uuid=UUID Set a specific machine UUID for the container\n" " -M --machine=NAME Set the machine name for the container\n" + " --uuid=UUID Set a specific machine UUID for the container\n" " -S --slice=SLICE Place the container in the specified slice\n" + " --private-network Disable network in container\n" + " --network-interface=INTERFACE\n" + " Assign an existing network interface to the\n" + " container\n" + " --network-veth Add a a virtual ethernet connection between host\n" + " and container\n" " -Z --selinux-context=SECLABEL\n" " Set the SELinux security context to be used by\n" " processes in the container\n" " -L --selinux-apifs-context=SECLABEL\n" " Set the SELinux security context to be used by\n" " API/tmpfs file systems in the container\n" - " --private-network Disable network in container\n" - " --network-interface=INTERFACE\n" - " Assign an existing network interface to the container\n" - " --share-system Share system namespaces with host\n" - " --read-only Mount the root directory read-only\n" " --capability=CAP In addition to the default, retain specified\n" " capability\n" " --drop-capability=CAP Drop the specified capability from the default set\n" " --link-journal=MODE Link up guest journal, one of no, auto, guest, host\n" " -j Equivalent to --link-journal=host\n" + " --read-only Mount the root directory read-only\n" " --bind=PATH[:PATH] Bind mount a file or directory from the host into\n" " the container\n" " --bind-ro=PATH[:PATH] Similar, but creates a read-only bind mount\n" " --setenv=NAME=VALUE Pass an environment variable to PID 1\n" + " --share-system Share system namespaces with host\n" " --register=BOOLEAN Register container as machine\n" " --keep-unit Do not register a scope for the machine, reuse\n" - " the service unit nspawn is running in\n" - " -q --quiet Do not show status information\n", + " the service unit nspawn is running in\n", program_invocation_short_name); return 0; @@ -186,7 +191,8 @@ static int parse_argv(int argc, char *argv[]) { ARG_SHARE_SYSTEM, ARG_REGISTER, ARG_KEEP_UNIT, - ARG_NETWORK_INTERFACE + ARG_NETWORK_INTERFACE, + ARG_NETWORK_VETH, }; static const struct option options[] = { @@ -213,6 +219,7 @@ static int parse_argv(int argc, char *argv[]) { { "register", required_argument, NULL, ARG_REGISTER }, { "keep-unit", no_argument, NULL, ARG_KEEP_UNIT }, { "network-interface", required_argument, NULL, ARG_NETWORK_INTERFACE }, + { "network-veth", no_argument, NULL, ARG_NETWORK_VETH }, {} }; @@ -252,6 +259,11 @@ static int parse_argv(int argc, char *argv[]) { break; + case ARG_NETWORK_VETH: + arg_network_veth = true; + arg_private_network = true; + break; + case ARG_NETWORK_INTERFACE: if (strv_push(&arg_network_interfaces, optarg) < 0) return log_oom(); @@ -1255,9 +1267,104 @@ static int reset_audit_loginuid(void) { return 0; } -static int move_network_interfaces(pid_t pid) { +static int setup_veth(int netns_fd) { + _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL; _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; + char iface_name[IFNAMSIZ] = "ve-"; + int r; + + if (!arg_private_network) + return 0; + + if (!arg_network_veth) + return 0; + + strncpy(iface_name+3, arg_machine, sizeof(iface_name) - 3); + + r = sd_rtnl_open(0, &rtnl); + if (r < 0) { + log_error("Failed to connect to netlink: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_new_link(RTM_NEWLINK, 0, &m); + if (r < 0) { + log_error("Failed to allocate netlink message: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_string(m, IFLA_IFNAME, "host0"); + if (r < 0) { + log_error("Failed to append netlink kind: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_open_container(m, IFLA_LINKINFO, 0); + if (r < 0) { + log_error("Failed to open netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_string(m, IFLA_INFO_KIND, "veth"); + if (r < 0) { + log_error("Failed to append netlink kind: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_open_container(m, IFLA_INFO_DATA, 0); + if (r < 0) { + log_error("Failed to open netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_open_container(m, VETH_INFO_PEER, sizeof(struct ifinfomsg)); + if (r < 0) { + log_error("z Failed to open netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_string(m, IFLA_IFNAME, iface_name); + if (r < 0) { + log_error("Failed to append netlink kind: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_FD, netns_fd); + if (r < 0) { + log_error("Failed to add netlink namespace field: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_close_container(m); + if (r < 0) { + log_error("Failed to close netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_close_container(m); + if (r < 0) { + log_error("Failed to close netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_message_close_container(m); + if (r < 0) { + log_error("Failed to close netlink container: %s", strerror(-r)); + return r; + } + + r = sd_rtnl_call(rtnl, m, 0, NULL); + if (r < 0) { + log_error("Failed to add new veth interfaces: %s", strerror(-r)); + return r; + } + + return 0; +} + +static int move_network_interfaces(pid_t pid) { _cleanup_udev_unref_ struct udev *udev = NULL; + _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL; char **i; int r; @@ -1326,15 +1433,16 @@ static int move_network_interfaces(pid_t pid) { } int main(int argc, char *argv[]) { - pid_t pid = 0; + + _cleanup_close_ int master = -1, kdbus_fd = -1, sync_fd = -1, netns_fd = -1; + _cleanup_close_pipe_ int kmsg_socket_pair[2] = { -1, -1 }; + _cleanup_free_ char *kdbus_domain = NULL; + _cleanup_fdset_free_ FDSet *fds = NULL; + const char *console = NULL; int r = EXIT_FAILURE, k; - _cleanup_close_ int master = -1, kdbus_fd = -1, sync_fd = -1; int n_fd_passed; - const char *console = NULL; + pid_t pid = 0; sigset_t mask; - _cleanup_close_pipe_ int kmsg_socket_pair[2] = { -1, -1 }; - _cleanup_fdset_free_ FDSet *fds = NULL; - _cleanup_free_ char *kdbus_domain = NULL; log_parse_environment(); log_open(); @@ -1429,6 +1537,13 @@ int main(int argc, char *argv[]) { goto finish; } + if (arg_network_veth) { + netns_fd = open("/proc/self/ns/net", O_RDWR|O_CLOEXEC); + if (netns_fd < 0) { + log_error("Failed to open network namespace fd: %m"); + goto finish; + } + } if (access("/dev/kdbus/control", F_OK) >= 0) { @@ -1584,6 +1699,14 @@ int main(int argc, char *argv[]) { dev_setup(arg_directory); + if (setup_veth(netns_fd) < 0) + goto child_fail; + + if (netns_fd >= 0) { + close_nointr_nofail(netns_fd); + netns_fd = -1; + } + if (setup_dev_console(arg_directory, console) < 0) goto child_fail; -- 2.30.2