add lxc-user-nic

.gitignore

@@ -67,6 +67,7 @@ src/lxc/lxc-unshare
 src/lxc/lxc-version
 src/lxc/lxc-wait
 src/lxc/legacy/lxc-ls
+src/lxc/lxc-user-nic
 
 src/python-lxc/build/
 src/python-lxc/lxc/__pycache__/
@@ -84,6 +85,7 @@ src/tests/lxc-test-lxcpath
 src/tests/lxc-test-saveconfig
 src/tests/lxc-test-shutdowntest
 src/tests/lxc-test-startone
+src/tests/lxc-usernic-test
 
 config/compile
 config/config.guess
@@ -110,3 +112,5 @@ src/stamp-h1
 
 .pc
 patches
+*.orig
+*.rej

src/lxc/Makefile.am

@@ -165,7 +165,8 @@ bin_PROGRAMS = \
 	lxc-kill \
 	lxc-config \
 	lxc-destroy \
-	lxc-create
+	lxc-create \
+	lxc-user-nic
 
 if HAVE_NEWUIDMAP
 bin_PROGRAMS += lxc-usernsexec
@@ -202,6 +203,7 @@ lxc_wait_SOURCES = lxc_wait.c
 lxc_kill_SOURCES = lxc_kill.c
 lxc_create_SOURCES = lxc_create.c
 lxc_usernsexec_SOURCES = lxc_usernsexec.c
+lxc_user_nic_SOURCES = lxc_user_nic.c
 
 install-exec-local: install-soPROGRAMS
 	mkdir -p $(DESTDIR)$(datadir)/lxc

src/lxc/lxc_clone.c

+/*
+ *
+ * Copyright © 2013 Serge Hallyn <serge.hallyn@ubuntu.com>.
+ * Copyright © 2013 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
 #include <unistd.h>
 #include <getopt.h>
 #include <signal.h>

src/lxc/lxc_user_nic.c

+/*
+ *
+ * Copyright © 2013 Serge Hallyn <serge.hallyn@ubuntu.com>.
+ * Copyright © 2013 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/file.h>
+#include <alloca.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <ctype.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <linux/netlink.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <netinet/in.h>
+#include <linux/if_bridge.h>
+#include <linux/rtnetlink.h>
+#include <linux/sockios.h>
+
+#if ISTEST
+#define CONF_FILE "/tmp/lxc-usernet"
+#define DB_FILE "/tmp/nics"
+#else
+/* TODO These should be set through configure.ac */
+#define CONF_FILE "/etc/lxc/lxc-usernet"
+#define DB_FILE "/var/lib/lxc/nics"
+#endif
+
+
+#include "nl.h"
+
+#ifndef IFLA_LINKMODE
+#  define IFLA_LINKMODE 17
+#endif
+
+#ifndef IFLA_LINKINFO
+#  define IFLA_LINKINFO 18
+#endif
+
+#ifndef IFLA_NET_NS_PID
+#  define IFLA_NET_NS_PID 19
+#endif
+
+#ifndef IFLA_INFO_KIND
+# define IFLA_INFO_KIND 1
+#endif
+
+#ifndef IFLA_VLAN_ID
+# define IFLA_VLAN_ID 1
+#endif
+
+#ifndef IFLA_INFO_DATA
+#  define IFLA_INFO_DATA 2
+#endif
+
+#ifndef VETH_INFO_PEER
+# define VETH_INFO_PEER 1
+#endif
+
+#ifndef IFLA_MACVLAN_MODE
+# define IFLA_MACVLAN_MODE 1
+#endif
+
+void usage(char *me, bool fail)
+{
+	printf("Usage: %s pid type bridge\n", me);
+	exit(fail ? 1 : 0);
+}
+
+int open_and_lock(char *path)
+{
+	int fd;
+	struct flock lk;
+
+	fd = open(path, O_RDWR|O_CREAT, S_IWUSR | S_IRUSR);
+	if (fd < 0) {
+		perror("open");
+		return(fd);
+	}
+
+	lk.l_type = F_WRLCK;
+	lk.l_whence = SEEK_SET;
+	lk.l_start = 0;
+	lk.l_len = 0;
+	if (fcntl(fd, F_SETLKW, &lk) < 0) {
+		perror("fcntl lock");
+		exit(1);
+	}
+
+	return fd;
+}
+
+
+char *get_username(char **buf)
+{
+	struct passwd pwd;
+	struct passwd *result;
+	int ret = getpwuid_r(getuid(), &pwd, *buf, 400, &result);
+
+	if (ret < 0) {
+		perror("getpwuid_r");
+		return NULL;
+	}
+
+	return pwd.pw_name;
+}
+
+/* The configuration file consists of lines of the form:
+ *
+ * user type bridge nic-name count
+ *
+ * We simply count the number of lines in the file, making sure that
+ * every listed nic is still present.  Any nics which have disappeared
+ * is removed when we count, in case the container died a harsh death
+ * without being able to clean up after itself.
+ */
+int get_alloted(char *me, char *intype, char *link)
+{
+	FILE *fin = fopen(CONF_FILE, "r");
+	char *line = NULL;
+	char user[100], type[100], br[100];
+	size_t len = 0;
+	int n = -1, ret;
+
+	if (!fin)
+		return -1;
+
+	while ((getline(&line, &len, fin)) != -1) {
+		ret = sscanf(line, "%99[^ \t] %99[^ \t] %99[^ \t] %d", user, type, br, &n);
+
+		if (ret != 4)
+			continue;
+		if (strcmp(user, me) != 0)
+			continue;
+		if (strcmp(type, intype) != 0)
+			continue;
+		if (strcmp(link, br) != 0)
+			continue;
+		free(line);
+		return n;
+	}
+	fclose(fin);
+	if (line)
+		free(line);
+	return -1;
+}
+
+char *get_eol(char *s)
+{
+	while (*s && *s != '\n')
+		s++;
+	return s;
+}
+
+char *get_eow(char *s)
+{
+	while (*s && !isblank(*s) && *s != '\n')
+		s++;
+	return s;
+}
+
+char *find_line(char *p, char *e, char *u, char *t, char *l)
+{
+	char *p1, *p2, *ret;
+	
+	while (p < e  && (p1 = get_eol(p)) < e) {
+		ret = p;
+		if (*p == '#')
+			goto next;
+		while (isblank(*p)) p++;
+		p2 = get_eow(p);
+		if (!p2 || p2-p != strlen(u) || strncmp(p, u, strlen(u)) != 0)
+			goto next;
+		p = p2+1;
+		while (isblank(*p)) p++;
+		p2 = get_eow(p);
+		if (!p2 || p2-p != strlen(t) || strncmp(p, t, strlen(t)) != 0)
+			goto next;
+		p = p2+1;
+		while (isblank(*p)) p++;
+		p2 = get_eow(p);
+		if (!p2 || p2-p != strlen(l) || strncmp(p, l, strlen(l)) != 0)
+			goto next;
+		return ret;
+next:
+		p = p1 + 1;
+	}
+
+	return NULL;
+}
+
+bool nic_exists(char *nic)
+{
+	char path[200];
+	int ret;
+	struct stat sb;
+
+#if ISTEST
+	ret = snprintf(path, 200, "/tmp/lxcnettest/%s", nic);
+#else
+	ret = snprintf(path, 200, "/sys/class/net/%s", nic);
+#endif
+	if (ret < 0 || ret >= 200)
+		exit(1);
+	ret = stat(path, &sb);
+	if (ret != 0)
+		return false;
+	return true;
+}
+
+#if ! ISTEST
+struct link_req {
+	struct nlmsg nlmsg;
+	struct ifinfomsg ifinfomsg;
+};
+
+int lxc_veth_create(const char *name1, const char *name2)
+{
+	struct nl_handler nlh;
+	struct nlmsg *nlmsg = NULL, *answer = NULL;
+	struct link_req *link_req;
+	struct rtattr *nest1, *nest2, *nest3;
+	int len, err;
+
+	err = netlink_open(&nlh, NETLINK_ROUTE);
+	if (err)
+		return err;
+
+	err = -EINVAL;
+	len = strlen(name1);
+	if (len == 1 || len >= IFNAMSIZ)
+		goto out;
+
+	len = strlen(name2);
+	if (len == 1 || len >= IFNAMSIZ)
+		goto out;
+
+	err = -ENOMEM;
+	nlmsg = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!nlmsg)
+		goto out;
+
+	answer = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!answer)
+		goto out;
+
+	link_req = (struct link_req *)nlmsg;
+	link_req->ifinfomsg.ifi_family = AF_UNSPEC;
+	nlmsg->nlmsghdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	nlmsg->nlmsghdr.nlmsg_flags =
+		NLM_F_REQUEST|NLM_F_CREATE|NLM_F_EXCL|NLM_F_ACK;
+	nlmsg->nlmsghdr.nlmsg_type = RTM_NEWLINK;
+
+	err = -EINVAL;
+	nest1 = nla_begin_nested(nlmsg, IFLA_LINKINFO);
+	if (!nest1)
+		goto out;
+
+	if (nla_put_string(nlmsg, IFLA_INFO_KIND, "veth"))
+		goto out;
+
+	nest2 = nla_begin_nested(nlmsg, IFLA_INFO_DATA);
+	if (!nest2)
+		goto out;
+
+	nest3 = nla_begin_nested(nlmsg, VETH_INFO_PEER);
+	if (!nest3)
+		goto out;
+
+	nlmsg->nlmsghdr.nlmsg_len += sizeof(struct ifinfomsg);
+
+	if (nla_put_string(nlmsg, IFLA_IFNAME, name2))
+		goto out;
+
+	nla_end_nested(nlmsg, nest3);
+
+	nla_end_nested(nlmsg, nest2);
+
+	nla_end_nested(nlmsg, nest1);
+
+	if (nla_put_string(nlmsg, IFLA_IFNAME, name1))
+		goto out;
+
+	err = netlink_transaction(&nlh, nlmsg, answer);
+out:
+	netlink_close(&nlh);
+	nlmsg_free(answer);
+	nlmsg_free(nlmsg);
+	return err;
+}
+
+int lxc_netdev_move(char *ifname, pid_t pid)
+{
+	struct nl_handler nlh;
+	struct nlmsg *nlmsg = NULL;
+	struct link_req *link_req;
+	int err, index;
+
+	index = if_nametoindex(ifname);
+	if (!ifname)
+		return -EINVAL;
+
+	err = netlink_open(&nlh, NETLINK_ROUTE);
+	if (err)
+		return err;
+
+	err = -ENOMEM;
+	nlmsg = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!nlmsg)
+		goto out;
+
+	link_req = (struct link_req *)nlmsg;
+	link_req->ifinfomsg.ifi_family = AF_UNSPEC;
+	link_req->ifinfomsg.ifi_index = index;
+	nlmsg->nlmsghdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	nlmsg->nlmsghdr.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
+	nlmsg->nlmsghdr.nlmsg_type = RTM_NEWLINK;
+
+	if (nla_put_u32(nlmsg, IFLA_NET_NS_PID, pid))
+		goto out;
+
+	err = netlink_transaction(&nlh, nlmsg, nlmsg);
+out:
+	netlink_close(&nlh);
+	nlmsg_free(nlmsg);
+	return err;
+}
+
+static int setup_private_host_hw_addr(char *veth1)
+{
+	struct ifreq ifr;
+	int err;
+	int sockfd;
+
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (sockfd < 0)
+		return -errno;
+
+	snprintf((char *)ifr.ifr_name, IFNAMSIZ, "%s", veth1);
+	err = ioctl(sockfd, SIOCGIFHWADDR, &ifr);
+	if (err < 0) {
+		close(sockfd);
+		return -errno;
+	}
+
+	ifr.ifr_hwaddr.sa_data[0] = 0xfe;
+	err = ioctl(sockfd, SIOCSIFHWADDR, &ifr);
+	close(sockfd);
+	if (err < 0)
+		return -errno;
+
+	return 0;
+}
+
+static int netdev_set_flag(const char *name, int flag)
+{
+	struct nl_handler nlh;
+	struct nlmsg *nlmsg = NULL, *answer = NULL;
+	struct link_req *link_req;
+	int index, len, err;
+
+	err = netlink_open(&nlh, NETLINK_ROUTE);
+	if (err)
+		return err;
+
+	err = -EINVAL;
+	len = strlen(name);
+	if (len == 1 || len >= IFNAMSIZ)
+		goto out;
+
+	err = -ENOMEM;
+	nlmsg = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!nlmsg)
+		goto out;
+
+	answer = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!answer)
+		goto out;
+
+	err = -EINVAL;
+	index = if_nametoindex(name);
+	if (!index)
+		goto out;
+
+	link_req = (struct link_req *)nlmsg;
+	link_req->ifinfomsg.ifi_family = AF_UNSPEC;
+	link_req->ifinfomsg.ifi_index = index;
+	link_req->ifinfomsg.ifi_change |= IFF_UP;
+	link_req->ifinfomsg.ifi_flags |= flag;
+	nlmsg->nlmsghdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	nlmsg->nlmsghdr.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
+	nlmsg->nlmsghdr.nlmsg_type = RTM_NEWLINK;
+
+	err = netlink_transaction(&nlh, nlmsg, answer);
+out:
+	netlink_close(&nlh);
+	nlmsg_free(nlmsg);
+	nlmsg_free(answer);
+	return err;
+}
+
+static int instanciate_veth(char *n1, char **n2)
+{
+	int err;
+
+	err = snprintf(*n2, IFNAMSIZ, "%sp", n1);
+	if (err < 0 || err >= IFNAMSIZ) {
+		fprintf(stderr, "nic name too long\n");
+		exit(1);
+	}
+
+	err = lxc_veth_create(n1, *n2);
+	if (err) {
+		fprintf(stderr, "failed to create %s-%s : %s\n", n1, *n2,
+		      strerror(-err));
+		exit(1);
+	}
+
+	/* changing the high byte of the mac address to 0xfe, the bridge interface
+	 * will always keep the host's mac address and not take the mac address
+	 * of a container */
+	err = setup_private_host_hw_addr(n1);
+	if (err) {
+		fprintf(stderr, "failed to change mac address of host interface '%s' : %s",
+			n1, strerror(-err));
+	}
+
+	return netdev_set_flag(n1, IFF_UP);
+}
+
+int lxc_bridge_attach(const char *bridge, const char *ifname)
+{
+	int fd, index, err;
+	struct ifreq ifr;
+
+	if (strlen(ifname) >= IFNAMSIZ)
+		return -EINVAL;
+
+	index = if_nametoindex(ifname);
+	if (!index)
+		return -EINVAL;
+
+	fd = socket(AF_INET, SOCK_STREAM, 0);
+	if (fd < 0)
+		return -errno;
+
+	strncpy(ifr.ifr_name, bridge, IFNAMSIZ);
+	ifr.ifr_ifindex = index;
+	err = ioctl(fd, SIOCBRADDIF, &ifr);
+	close(fd);
+	if (err)
+		err = -errno;
+
+	return err;
+}
+
+int lxc_netdev_delete_by_index(int ifindex)
+{
+	struct nl_handler nlh;
+	struct nlmsg *nlmsg = NULL, *answer = NULL;
+	struct link_req *link_req;
+	int err;
+
+	err = netlink_open(&nlh, NETLINK_ROUTE);
+	if (err)
+		return err;
+
+	err = -ENOMEM;
+	nlmsg = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!nlmsg)
+		goto out;
+
+	answer = nlmsg_alloc(NLMSG_GOOD_SIZE);
+	if (!answer)
+		goto out;
+
+	link_req = (struct link_req *)nlmsg;
+	link_req->ifinfomsg.ifi_family = AF_UNSPEC;
+	link_req->ifinfomsg.ifi_index = ifindex;
+	nlmsg->nlmsghdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	nlmsg->nlmsghdr.nlmsg_flags = NLM_F_ACK|NLM_F_REQUEST;
+	nlmsg->nlmsghdr.nlmsg_type = RTM_DELLINK;
+
+	err = netlink_transaction(&nlh, nlmsg, answer);
+out:
+	netlink_close(&nlh);
+	nlmsg_free(answer);
+	nlmsg_free(nlmsg);
+	return err;
+}
+
+int lxc_netdev_delete_by_name(const char *name)
+{
+	int index;
+
+	index = if_nametoindex(name);
+	if (!index)
+		return -EINVAL;
+
+	return lxc_netdev_delete_by_index(index);
+}
+#else
+int lxc_netdev_delete_by_name(const char *name)
+{
+	char path[200];
+	sprintf(path, "/tmp/lxcnettest/%s", name);
+	return unlink(path);
+}
+
+#endif
+
+bool create_nic(char *nic, char *br, char *pidstr)
+{
+#if ISTEST
+	char path[200];
+	sprintf(path, "/tmp/lxcnettest/%s", nic);
+	int fd = open(path, O_RDWR|O_CREAT, S_IWUSR | S_IRUSR);
+	if (fd < 0)
+		return false;
+	close(fd);
+	return true;
+#else
+	// not yet implemented
+	char *veth1buf, *veth2buf;
+	veth1buf = alloca(IFNAMSIZ);
+	veth2buf = alloca(IFNAMSIZ);
+	int ret;
+	int pid = atoi(pidstr);
+
+	ret = snprintf(veth1buf, IFNAMSIZ, "%s", nic);
+	if (ret < 0 || ret >= IFNAMSIZ) {
+		fprintf(stderr, "nic name too long\n");
+		exit(1);
+	}
+
+	/* create the nics */
+	if (instanciate_veth(veth1buf, &veth2buf) < 0) {
+		fprintf(stderr, "Error creating veth tunnel\n");
+		return false;
+	}
+
+	/* attach veth1 to bridge */
+	if (lxc_bridge_attach(br, veth1buf) < 0) {
+		fprintf(stderr, "Error attaching %s to %s\n", veth1buf, br);
+		goto out_del;
+	}
+
+	/* pass veth2 to target netns */
+	ret = lxc_netdev_move(veth2buf, pid);
+	if (ret < 0) {
+		fprintf(stderr, "Error moving %s to netns %d\n", veth2buf, pid);
+		goto out_del;
+	}
+	return true;
+
+out_del:
+	lxc_netdev_delete_by_name(veth1buf);
+	exit(1);
+#endif
+}
+
+void get_new_nicname(char **dest, char *br, char *pid)
+{
+	int i = 0;
+	// TODO - speed this up.  For large installations we won't
+	// want n stats for every nth container startup.
+	while (1) {
+		sprintf(*dest, "lxcuser-%d", i);
+		if (!nic_exists(*dest) && create_nic(*dest, br, pid))
+			return;
+		i++;
+	}
+}
+
+bool get_nic_from_line(char *p, char **nic)
+{
+	char user[100], type[100], br[100];
+	int ret;
+
+	ret = sscanf(p, "%99[^ \t\n] %99[^ \t\n] %99[^ \t\n] %99[^ \t\n]", user, type, br, *nic);
+	if (ret != 4)
+		return false;
+	return true;
+}
+
+bool cull_entries(int fd, char *me, char *t, char *br)
+{
+	struct stat sb;
+	char *buf, *p, *e, *nic;
+	off_t len;
+
+	nic = alloca(100);
+
+	fstat(fd, &sb);
+	len = sb.st_size;
+	if (len == 0)
+		return true;
+	buf = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+	if (buf == MAP_FAILED) {
+		fprintf(stderr, "Failed to create mapping: error %d\n", errno);
+		return false;
+	}
+
+	p = buf;
+	e = buf + len;
+	while ((p = find_line(p, e, me, t, br)) != NULL) {
+		if (!get_nic_from_line(p, &nic))
+			continue;
+		if (nic && !nic_exists(nic)) {
+			// copy from eol(p)+1..e to p
+			char *src = get_eol(p) + 1, *dest = p;
+			int diff = src - p;
+			while (src < e)
+				*(dest++) = *(src)++;
+			e -= diff;
+		} else
+			p = get_eol(p) + 1;
+		if (p >= e)
+			break;
+	}
+	munmap(buf, sb.st_size);
+	if (ftruncate(fd, e-buf))
+		fprintf(stderr, "Failed to set new file size\n");
+	return true;
+}
+
+int count_entries(char *buf, off_t len, char *me, char *t, char *br)
+{
+	char *e = &buf[len];
+	int count = 0;
+	while ((buf = find_line(buf, e, me, t, br)) != NULL) {
+		count++;
+		buf = get_eol(buf)+1;
+		if (buf >= e)
+			break;
+	}
+
+	return count;
+}
+
+/*
+ * The dbfile has lines of the format:
+ * user type bridge nicname
+ */
+bool get_nic_if_avail(int fd, char *me, char *pid, char *intype, char *br, int allowed, char **nicname)
+{
+	off_t len, slen;
+	struct stat sb;
+	char *buf = NULL, *newline;
+	int ret, count = 0;
+
+	cull_entries(fd, me, intype, br);
+
+	fstat(fd, &sb);
+	len = sb.st_size;
+	if (len != 0) {
+		buf = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+		if (buf == MAP_FAILED) {
+			fprintf(stderr, "Failed to create mapping\n");
+			return false;
+		}
+
+		count = count_entries(buf, len, me, intype, br);
+		if (count >= allowed)
+			return false;
+	}
+
+
+	get_new_nicname(nicname, br, pid);
+	/* me  ' ' intype ' ' br ' ' *nicname + '\n' + '\0' */
+	slen = strlen(me) + strlen(intype) + strlen(br) + strlen(*nicname) + 5;
+	newline = alloca(slen);
+	ret = snprintf(newline, slen, "%s %s %s %s\n", me, intype, br, *nicname);
+	if (ret < 0 || ret >= slen) {
+		if (lxc_netdev_delete_by_name(*nicname) != 0)
+			fprintf(stderr, "Error unlinking %s!\n", *nicname);
+		return false;
+	}
+	if (len)
+		munmap(buf, len);
+	if (ftruncate(fd, len + slen))
+		fprintf(stderr, "Failed to set new file size\n");
+	buf = mmap(NULL, len + slen, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+	if (buf == MAP_FAILED) {
+		fprintf(stderr, "Failed to create mapping after extending: error %d\n", errno);
+		if (lxc_netdev_delete_by_name(*nicname) != 0)
+			fprintf(stderr, "Error unlinking %s!\n", *nicname);
+		return false;
+	}
+	strcpy(buf+len, newline);
+	munmap(buf, len+slen);
+	return true;
+}
+
+int main(int argc, char *argv[])
+{
+	int n, fd;
+	bool gotone = false;
+	char *me, *buf = alloca(400);
+	char *nicname = alloca(40);
+
+	if ((me = get_username(&buf)) == NULL) {
+		printf("Failed to get username\n");
+		exit(1);
+	}
+
+	if (argc != 4)
+		usage(argv[0], true);
+
+	if ((fd = open_and_lock(DB_FILE)) < 0) {
+		printf("Failed to lock %s\n", DB_FILE);
+		exit(1);
+	}
+
+	n = get_alloted(me, argv[2], argv[3]);
+	if (n > 0)
+		gotone = get_nic_if_avail(fd, me, argv[1], argv[2], argv[3], n, &nicname);
+	close(fd);
+	if (!gotone) {
+		printf("Quota reached\n");
+		exit(1);
+	}
+	printf("got nic name %s\n", nicname);
+
+	// Now create the link
+
+	exit(0);
+}

src/tests/Makefile.am

@@ -15,6 +15,8 @@ lxc_test_lxcpath_SOURCES = lxcpath.c
 lxc_test_cgpath_SOURCES = cgpath.c
 lxc_test_clonetest_SOURCES = clonetest.c
 lxc_test_console_SOURCES = console.c
+lxc_usernic_test_SOURCES = ../lxc/lxc_user_nic.c ../lxc/nl.c
+lxc_usernic_test_CFLAGS = -DISTEST
 
 AM_CFLAGS=-I$(top_srcdir)/src \
 	-DLXCROOTFSMOUNT=\"$(LXCROOTFSMOUNT)\" \
@@ -26,7 +28,9 @@ AM_CFLAGS=-I$(top_srcdir)/src \
 bin_PROGRAMS = lxc-test-containertests lxc-test-locktests lxc-test-startone \
 	lxc-test-destroytest lxc-test-saveconfig lxc-test-createtest \
 	lxc-test-shutdowntest lxc-test-get_item lxc-test-getkeys lxc-test-lxcpath \
-	lxc-test-cgpath lxc-test-clonetest lxc-test-console
+	lxc-test-cgpath lxc-test-clonetest lxc-test-console lxc-usernic-test
+
+bin_SCRIPTS = lxc-test-usernic
 
 endif
 

src/tests/lxc-test-usernic

+#!/bin/bash
+
+# lxc: linux Container library
+
+# Authors:
+# Serge Hallyn <serge.hallyn@ubuntu.com>
+#
+# This is a test script for the lxc-user-nic program
+
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+conffile="/tmp/lxc-usernet"
+dbfile="/tmp/nics"
+sysfsdir=/tmp/lxcnettest
+
+rm -f $conffile $dbfile
+
+rm -rf $sysfsdir
+mkdir -p $sysfsdir
+
+# there is no conffile, so we have no permissions
+lxc-usernic-test 1111 veth lxcbr0 > /dev/null 2>&1
+if [ $? -eq 0 ]; then
+	echo "Fail: empty conffile should not allow me a nic"
+	exit 1
+fi
+
+cat > $conffile << EOF
+$(id -un) veth lxcbr0 1
+EOF
+
+# Should be allowed one but not two
+lxc-usernic-test 1111 veth lxcbr0 > /dev/null 2>&1
+if [ $? -ne 0 ]; then
+	echo "Failed to get one allowed nic"
+	exit 1
+fi
+
+lxc-usernic-test 1111 veth lxcbr0 > /dev/null 2>&1
+if [ $? -eq 0 ]; then
+	echo "Fail: was able to get a second nic"
+	exit 1
+fi
+
+# now remove the 'existing nic' and make sure we're allowed to create
+# a new one
+lxc-usernic-test 1111 veth lxcbr0 > /dev/null 2>&1
+rm -rf $sysfsdir
+mkdir -p $sysfsdir
+if [ $? -ne 0 ]; then
+	echo "Fail: was unable to get a replacement nic"
+	exit 1
+fi
+
+echo "All tests passed"