cmd: lxc-user-nic: change log macro & cleanups

src/lxc/Makefile.am

@@ -321,6 +321,7 @@ if ENABLE_COMMANDS
 init_lxc_SOURCES = cmd/lxc_init.c
 lxc_monitord_SOURCES = cmd/lxc_monitord.c
 lxc_user_nic_SOURCES = cmd/lxc_user_nic.c \
+		       log.c log.h \
 		       namespace.c namespace.h \
 		       network.c network.h \
 		       parse.c parse.h

src/lxc/cmd/lxc_user_nic.c

@@ -46,6 +46,7 @@
 #include <sys/types.h>
 
 #include "config.h"
+#include "log.h"
 #include "namespace.h"
 #include "network.h"
 #include "parse.h"
@@ -72,9 +73,9 @@ static void usage(char *me, bool fail)
 	fprintf(stderr, "{nicname} is the name to use inside the container\n");
 
 	if (fail)
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 
-	exit(EXIT_SUCCESS);
+	_exit(EXIT_SUCCESS);
 }
 
 static int open_and_lock(char *path)
@@ -84,8 +85,7 @@ static int open_and_lock(char *path)
 
 	fd = open(path, O_RDWR | O_CREAT, S_IWUSR | S_IRUSR);
 	if (fd < 0) {
-		usernic_error("Failed to open \"%s\": %s\n", path,
-			      strerror(errno));
+		CMD_SYSERROR("Failed to open \"%s\"\n", path);
 		return -1;
 	}
 
@@ -96,8 +96,7 @@ static int open_and_lock(char *path)
 
 	ret = fcntl(fd, F_SETLKW, &lk);
 	if (ret < 0) {
-		usernic_error("Failed to lock \"%s\": %s\n", path,
-			      strerror(errno));
+		CMD_SYSERROR("Failed to lock \"%s\"\n", path);
 		close(fd);
 		return -1;
 	}
@@ -127,7 +126,7 @@ static char *get_username(void)
 		if (ret == 0)
 			usernic_error("%s", "Could not find matched password record\n");
 
-		usernic_error("Failed to get username: %s(%u)\n", strerror(errno), getuid());
+		CMD_SYSERROR("Failed to get username: %u\n", getuid());
 		free(buf);
 		return NULL;
 	}
@@ -164,35 +163,29 @@ static char **get_groupnames(void)
 
 	ngroups = getgroups(0, NULL);
 	if (ngroups < 0) {
-		usernic_error("Failed to get number of groups the user "
-			      "belongs to: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to get number of groups the user belongs to\n");
 		return NULL;
-	}
-	if (ngroups == 0)
+	} else if (ngroups == 0) {
 		return NULL;
+	}
 
 	group_ids = malloc(sizeof(gid_t) * ngroups);
 	if (!group_ids) {
-		usernic_error("Failed to allocate memory while getting groups "
-			      "the user belongs to: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to allocate memory while getting groups the user belongs to\n");
 		return NULL;
 	}
 
 	ret = getgroups(ngroups, group_ids);
 	if (ret < 0) {
 		free(group_ids);
-		usernic_error("Failed to get process groups: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to get process groups\n");
 		return NULL;
 	}
 
 	groupnames = malloc(sizeof(char *) * (ngroups + 1));
 	if (!groupnames) {
 		free(group_ids);
-		usernic_error("Failed to allocate memory while getting group "
-			      "names: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to allocate memory while getting group names\n");
 		return NULL;
 	}
 
@@ -206,9 +199,7 @@ static char **get_groupnames(void)
 	if (!buf) {
 		free(group_ids);
 		free_groupnames(groupnames);
-		usernic_error("Failed to allocate memory while getting group "
-			      "names: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to allocate memory while getting group names\n");
 		return NULL;
 	}
 
@@ -218,8 +209,7 @@ static char **get_groupnames(void)
 			if (ret == 0)
 				usernic_error("%s", "Could not find matched group record\n");
 
-			usernic_error("Failed to get group name: %s(%u)\n",
-				      strerror(errno), group_ids[i]);
+			CMD_SYSERROR("Failed to get group name: %u\n", group_ids[i]);
 			free(buf);
 			free(group_ids);
 			free_groupnames(groupnames);
@@ -228,8 +218,7 @@ static char **get_groupnames(void)
 
 		groupnames[i] = strdup(grent.gr_name);
 		if (!groupnames[i]) {
-			usernic_error("Failed to copy group name \"%s\"",
-				      grent.gr_name);
+			usernic_error("Failed to copy group name \"%s\"", grent.gr_name);
 			free(buf);
 			free(group_ids);
 			free_groupnames(groupnames);
@@ -250,6 +239,7 @@ static bool name_is_in_groupnames(char *name, char **groupnames)
 			return true;
 		groupnames++;
 	}
+
 	return false;
 }
 
@@ -272,8 +262,7 @@ static struct alloted_s *append_alloted(struct alloted_s **head, char *name,
 
 	al = malloc(sizeof(struct alloted_s));
 	if (!al) {
-		usernic_error("Failed to allocate memory: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to allocate memory\n");
 		return NULL;
 	}
 
@@ -331,15 +320,13 @@ static int get_alloted(char *me, char *intype, char *link,
 	char name[100], type[100], br[100];
 	char **groups;
 	FILE *fin;
-
 	int count = 0;
 	size_t len = 0;
 	char *line = NULL;
 
 	fin = fopen(LXC_USERNIC_CONF, "r");
 	if (!fin) {
-		usernic_error("Failed to open \"%s\": %s\n", LXC_USERNIC_CONF,
-			      strerror(errno));
+		CMD_SYSERROR("Failed to open \"%s\"\n", LXC_USERNIC_CONF);
 		return -1;
 	}
 
@@ -381,6 +368,7 @@ static int get_alloted(char *me, char *intype, char *link,
 			count = 0;
 			break;
 		}
+
 		count += n;
 	}
 
@@ -396,6 +384,7 @@ static char *get_eol(char *s, char *e)
 {
 	while ((s < e) && *s && (*s != '\n'))
 		s++;
+
 	return s;
 }
 
@@ -403,6 +392,7 @@ static char *get_eow(char *s, char *e)
 {
 	while ((s < e) && *s && !isblank(*s) && (*s != '\n'))
 		s++;
+
 	return s;
 }
 
@@ -505,8 +495,8 @@ static int instantiate_veth(char *veth1, char *veth2)
 
 	ret = lxc_veth_create(veth1, veth2);
 	if (ret < 0) {
-		usernic_error("Failed to create %s-%s : %s.\n", veth1, veth2,
-			      strerror(-ret));
+		errno = -ret;
+		CMD_SYSERROR("Failed to create %s-%s\n", veth1, veth2);
 		return -1;
 	}
 
@@ -515,9 +505,10 @@ static int instantiate_veth(char *veth1, char *veth2)
 	 * mac address of a container.
 	 */
 	ret = setup_private_host_hw_addr(veth1);
-	if (ret < 0)
-		usernic_error("Failed to change mac address of host interface "
-			      "%s : %s\n", veth1, strerror(-ret));
+	if (ret < 0) {
+		errno = -ret;
+		CMD_SYSERROR("Failed to change mac address of host interface %s\n", veth1);
+	}
 
 	return netdev_set_flag(veth1, IFF_UP);
 }
@@ -529,6 +520,7 @@ static int get_mtu(char *name)
 	idx = if_nametoindex(name);
 	if (idx < 0)
 		return -1;
+
 	return netdev_get_mtu(idx);
 }
 
@@ -548,6 +540,7 @@ static int create_nic(char *nic, char *br, int pid, char **cnic)
 		usernic_error("%s\n", "Could not create nic name");
 		return -1;
 	}
+
 	/* create the nics */
 	ret = instantiate_veth(veth1buf, veth2buf);
 	if (ret < 0) {
@@ -562,14 +555,14 @@ static int create_nic(char *nic, char *br, int pid, char **cnic)
 			ret = lxc_netdev_set_mtu(veth1buf, mtu);
 			if (ret < 0) {
 				usernic_error("Failed to set mtu to %d on %s\n",
-					      mtu, veth1buf);
+				              mtu, veth1buf);
 				goto out_del;
 			}
 
 			ret = lxc_netdev_set_mtu(veth2buf, mtu);
 			if (ret < 0) {
 				usernic_error("Failed to set mtu to %d on %s\n",
-					      mtu, veth2buf);
+				              mtu, veth2buf);
 				goto out_del;
 			}
 		}
@@ -586,7 +579,7 @@ static int create_nic(char *nic, char *br, int pid, char **cnic)
 	ret = lxc_netdev_move_by_name(veth2buf, pid, NULL);
 	if (ret < 0) {
 		usernic_error("Error moving %s to network namespace of %d\n",
-			      veth2buf, pid);
+		              veth2buf, pid);
 		goto out_del;
 	}
 
@@ -621,7 +614,7 @@ static bool cull_entries(int fd, char *name, char *net_type, char *net_link,
 
 	ret = fstat(fd, &sb);
 	if (ret < 0) {
-		usernic_error("Failed to fstat: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to fstat\n");
 		return false;
 	}
 
@@ -630,8 +623,7 @@ static bool cull_entries(int fd, char *name, char *net_type, char *net_link,
 
 	buf = lxc_strmmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 	if (buf == MAP_FAILED) {
-		usernic_error("Failed to establish shared memory mapping: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to establish shared memory mapping\n");
 		return false;
 	}
 
@@ -664,6 +656,7 @@ static bool cull_entries(int fd, char *name, char *net_type, char *net_link,
 	}
 
 	buf_start = buf;
+
 	for (i = 0; i < n; i++) {
 		if (!entry_lines[i].keep)
 			continue;
@@ -673,13 +666,13 @@ static bool cull_entries(int fd, char *name, char *net_type, char *net_link,
 		*buf_start = '\n';
 		buf_start++;
 	}
+
 	free(entry_lines);
 
 	ret = ftruncate(fd, buf_start - buf);
 	lxc_strmunmap(buf, sb.st_size);
 	if (ret < 0)
-		usernic_error("Failed to set new file size: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to set new file size\n");
 
 	return true;
 }
@@ -695,6 +688,7 @@ static int count_entries(char *buf, off_t len, char *name, char *net_type, char
 				&owner, &(bool){true}, &(bool){true}))) {
 		if (owner)
 			count++;
+
 		buf = get_eol(buf, buf_end) + 1;
 		if (buf >= buf_end)
 			break;
@@ -726,7 +720,7 @@ static char *get_nic_if_avail(int fd, struct alloted_s *names, int pid,
 
 	ret = fstat(fd, &sb);
 	if (ret < 0) {
-		usernic_error("Failed to fstat: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to fstat\n");
 		return NULL;
 	}
 
@@ -734,12 +728,12 @@ static char *get_nic_if_avail(int fd, struct alloted_s *names, int pid,
 		buf = lxc_strmmap(NULL, sb.st_size, PROT_READ | PROT_WRITE,
 				  MAP_SHARED, fd, 0);
 		if (buf == MAP_FAILED) {
-			usernic_error("Failed to establish shared memory "
-				      "mapping: %s\n", strerror(errno));
+			CMD_SYSERROR("Failed to establish shared memory mapping\n");
 			return NULL;
 		}
 
 		owner = NULL;
+
 		for (n = names; n != NULL; n = n->next) {
 			count = count_entries(buf, sb.st_size, n->name, intype, br);
 			if (count >= n->allowed)
@@ -790,7 +784,7 @@ static char *get_nic_if_avail(int fd, struct alloted_s *names, int pid,
 	newline = malloc(slen + 1);
 	if (!newline) {
 		free(newline);
-		usernic_error("Failed allocate memory: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed allocate memory\n");
 		return NULL;
 	}
 
@@ -798,6 +792,7 @@ static char *get_nic_if_avail(int fd, struct alloted_s *names, int pid,
 	if (ret < 0 || (size_t)ret >= (slen + 1)) {
 		if (lxc_netdev_delete_by_name(nicname) != 0)
 			usernic_error("Error unlinking %s\n", nicname);
+
 		free(newline);
 		return NULL;
 	}
@@ -807,15 +802,16 @@ static char *get_nic_if_avail(int fd, struct alloted_s *names, int pid,
 	 */
 	ret = ftruncate(fd, sb.st_size + slen);
 	if (ret < 0)
-		usernic_error("Failed to truncate file: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to truncate file\n");
 
 	buf = lxc_strmmap(NULL, sb.st_size + slen, PROT_READ | PROT_WRITE,
 			  MAP_SHARED, fd, 0);
 	if (buf == MAP_FAILED) {
-		usernic_error("Failed to establish shared memory mapping: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to establish shared memory mapping\n");
+
 		if (lxc_netdev_delete_by_name(nicname) != 0)
 			usernic_error("Error unlinking %s\n", nicname);
+
 		free(newline);
 		return NULL;
 	}
@@ -845,6 +841,7 @@ static bool create_db_dir(char *fnam)
 again:
 	while (*p && *p != '/')
 		p++;
+
 	if (!*p)
 		return true;
 
@@ -852,11 +849,11 @@ again:
 
 	ret = mkdir(fnam, 0755);
 	if (ret < 0 && errno != EEXIST) {
-		usernic_error("Failed to create %s: %s\n", fnam,
-			      strerror(errno));
+		CMD_SYSERROR("Failed to create %s\n", fnam);
 		*p = '/';
 		return false;
 	}
+
 	*(p++) = '/';
 
 	goto again;
@@ -873,6 +870,7 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 	int fd = -1, ifindex = -1, ofd = -1;
 
 	pid_self = lxc_raw_getpid();
+
 	ofd = lxc_preserve_ns(pid_self, "net");
 	if (ofd < 0) {
 		usernic_error("Failed opening network namespace path for %d", pid_self);
@@ -887,9 +885,7 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 
 	ret = getresuid(&ruid, &euid, &suid);
 	if (ret < 0) {
-		usernic_error("Failed to retrieve real, effective, and saved "
-			      "user IDs: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to retrieve real, effective, and saved user IDs\n");
 		goto do_partial_cleanup;
 	}
 
@@ -897,18 +893,16 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 	close(fd);
 	fd = -1;
 	if (ret < 0) {
-		usernic_error("Failed to setns() to the network namespace of "
-			      "the container with PID %d: %s\n",
-			      pid, strerror(errno));
+		CMD_SYSERROR("Failed to setns() to the network namespace of "
+		             "the container with PID %d\n", pid);
 		goto do_partial_cleanup;
 	}
 
 	ret = setresuid(ruid, ruid, 0);
 	if (ret < 0) {
-		usernic_error("Failed to drop privilege by setting effective "
-			      "user id and real user id to %d, and saved user "
-			      "ID to 0: %s\n",
-			      ruid, strerror(errno));
+		CMD_SYSERROR("Failed to drop privilege by setting effective "
+		             "user id and real user id to %d, and saved user "
+		             "ID to 0\n", ruid);
 		/* It's ok to jump to do_full_cleanup here since setresuid()
 		 * will succeed when trying to set real, effective, and saved to
 		 * values they currently have.
@@ -919,7 +913,7 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 	/* Check if old interface exists. */
 	ifindex = if_nametoindex(oldname);
 	if (!ifindex) {
-		usernic_error("Failed to get netdev index: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to get netdev index\n");
 		goto do_full_cleanup;
 	}
 
@@ -936,13 +930,13 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 	name = NULL;
 	if (ret < 0) {
 		usernic_error("Error %d renaming netdev %s to %s in container\n",
-			      ret, oldname, newname ? newname : "eth%d");
+		              ret, oldname, newname ? newname : "eth%d");
 		goto do_full_cleanup;
 	}
 
 	/* Retrieve new name for interface. */
 	if (!if_indextoname(ifindex, ifname)) {
-		usernic_error("Failed to get new netdev name: %s\n", strerror(errno));
+		CMD_SYSERROR("Failed to get new netdev name\n");
 		goto do_full_cleanup;
 	}
 
@@ -954,18 +948,17 @@ static char *lxc_secure_rename_in_ns(int pid, char *oldname, char *newname,
 do_full_cleanup:
 	ret = setresuid(ruid, euid, suid);
 	if (ret < 0) {
-		usernic_error("Failed to restore privilege by setting "
-			      "effective user id to %d, real user id to %d, "
-			      "and saved user ID to %d: %s\n", ruid, euid, suid,
-			      strerror(errno));
+		CMD_SYSERROR("Failed to restore privilege by setting "
+		             "effective user id to %d, real user id to %d, "
+		             "and saved user ID to %d\n", ruid, euid, suid);
 
 		string_ret = NULL;
 	}
 
 	ret = setns(ofd, CLONE_NEWNET);
 	if (ret < 0) {
-		usernic_error("Failed to setns() to original network namespace "
-			      "of PID %d: %s\n", ofd, strerror(errno));
+		CMD_SYSERROR("Failed to setns() to original network namespace "
+		             "of PID %d\n", ofd);
 
 		string_ret = NULL;
 	}
@@ -994,18 +987,15 @@ static bool may_access_netns(int pid)
 
 	ret = getresuid(&ruid, &euid, &suid);
 	if (ret < 0) {
-		usernic_error("Failed to retrieve real, effective, and saved "
-			      "user IDs: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to retrieve real, effective, and saved user IDs\n");
 		return false;
 	}
 
 	ret = setresuid(ruid, ruid, euid);
 	if (ret < 0) {
-		usernic_error("Failed to drop privilege by setting effective "
-			      "user id and real user id to %d, and saved user "
-			      "ID to %d: %s\n",
-			      ruid, euid, strerror(errno));
+		CMD_SYSERROR("Failed to drop privilege by setting effective "
+		             "user id and real user id to %d, and saved user "
+		             "ID to %d\n", ruid, euid);
 		return false;
 	}
 
@@ -1017,14 +1007,13 @@ static bool may_access_netns(int pid)
 	may_access = true;
 	if (ret < 0)  {
 		may_access = false;
-		usernic_error("Uid %d may not access %s: %s\n", (int)ruid, s, strerror(errno));
+		CMD_SYSERROR("Uid %d may not access %s\n", (int)ruid, s);
 	}
 
 	ret = setresuid(ruid, euid, suid);
 	if (ret < 0) {
-		usernic_error("Failed to restore user id to %d, real user id "
-			      "to %d, and saved user ID to %d: %s\n",
-			      ruid, euid, suid, strerror(errno));
+		CMD_SYSERROR("Failed to restore user id to %d, real user id "
+		             "to %d, and saved user ID to %d\n", ruid, euid, suid);
 		may_access = false;
 	}
 
@@ -1053,6 +1042,7 @@ static bool is_privileged_over_netns(int netns_fd)
 	int ofd = -1;
 
 	pid_self = lxc_raw_getpid();
+
 	ofd = lxc_preserve_ns(pid_self, "net");
 	if (ofd < 0) {
 		usernic_error("Failed opening network namespace path for %d", pid_self);
@@ -1061,25 +1051,21 @@ static bool is_privileged_over_netns(int netns_fd)
 
 	ret = getresuid(&ruid, &euid, &suid);
 	if (ret < 0) {
-		usernic_error("Failed to retrieve real, effective, and saved "
-			      "user IDs: %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to retrieve real, effective, and saved user IDs\n");
 		goto do_partial_cleanup;
 	}
 
 	ret = setns(netns_fd, CLONE_NEWNET);
 	if (ret < 0) {
-		usernic_error("Failed to setns() to network namespace %s\n",
-			      strerror(errno));
+		CMD_SYSERROR("Failed to setns() to network namespace\n");
 		goto do_partial_cleanup;
 	}
 
 	ret = setresuid(ruid, ruid, 0);
 	if (ret < 0) {
-		usernic_error("Failed to drop privilege by setting effective "
-			      "user id and real user id to %d, and saved user "
-			      "ID to 0: %s\n",
-			      ruid, strerror(errno));
+		CMD_SYSERROR("Failed to drop privilege by setting effective "
+		             "user id and real user id to %d, and saved user "
+		             "ID to 0\n", ruid);
 		/* It's ok to jump to do_full_cleanup here since setresuid()
 		 * will succeed when trying to set real, effective, and saved to
 		 * values they currently have.
@@ -1099,24 +1085,20 @@ static bool is_privileged_over_netns(int netns_fd)
 do_full_cleanup:
 	ret = setresuid(ruid, euid, suid);
 	if (ret < 0) {
-		usernic_error("Failed to restore privilege by setting "
-			      "effective user id to %d, real user id to %d, "
-			      "and saved user ID to %d: %s\n", ruid, euid, suid,
-			      strerror(errno));
-
+		CMD_SYSERROR("Failed to restore privilege by setting "
+		             "effective user id to %d, real user id to %d, "
+		             "and saved user ID to %d\n", ruid, euid, suid);
 		bret = false;
 	}
 
 	ret = setns(ofd, CLONE_NEWNET);
 	if (ret < 0) {
-		usernic_error("Failed to setns() to original network namespace "
-			      "of PID %d: %s\n", ofd, strerror(errno));
-
+		CMD_SYSERROR("Failed to setns() to original network namespace "
+		             "of PID %d\n", ofd);
 		bret = false;
 	}
 
 do_partial_cleanup:
-
 	close(ofd);
 	return bret;
 }
@@ -1132,10 +1114,11 @@ int main(int argc, char *argv[])
 
 	if (argc < 7 || argc > 8) {
 		usage(argv[0], true);
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	memset(&args, 0, sizeof(struct user_nic_args));
+
 	args.cmd = argv[1];
 	args.lxc_path = argv[2];
 	args.lxc_name = argv[3];
@@ -1151,33 +1134,33 @@ int main(int argc, char *argv[])
 		request = LXC_USERNIC_DELETE;
 	} else {
 		usage(argv[0], true);
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	/* Set a sane env, because we are setuid-root. */
 	ret = clearenv();
 	if (ret) {
 		usernic_error("%s", "Failed to clear environment\n");
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	ret = setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", 1);
 	if (ret < 0) {
 		usernic_error("%s", "Failed to set PATH, exiting\n");
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	me = get_username();
 	if (!me) {
 		usernic_error("%s", "Failed to get username\n");
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	if (request == LXC_USERNIC_CREATE) {
 		ret = lxc_safe_int(args.pid, &pid);
 		if (ret < 0) {
 			usernic_error("Could not read pid: %s\n", args.pid);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 	} else if (request == LXC_USERNIC_DELETE) {
 		char opath[LXC_PROC_PID_FD_LEN];
@@ -1191,60 +1174,66 @@ int main(int argc, char *argv[])
 		netns_fd = open(args.pid, O_PATH | O_CLOEXEC);
 		if (netns_fd < 0) {
 			usernic_error("Failed to open \"%s\"\n", args.pid);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 
 		if (!fhas_fs_type(netns_fd, NSFS_MAGIC)) {
 			usernic_error("Path \"%s\" does not refer to a network namespace path\n", args.pid);
 			close(netns_fd);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 
 		ret = snprintf(opath, sizeof(opath), "/proc/self/fd/%d", netns_fd);
 		if (ret < 0 || (size_t)ret >= sizeof(opath)) {
 			close(netns_fd);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 
 		/* Now get an fd that we can use in setns() calls. */
 		ret = open(opath, O_RDONLY | O_CLOEXEC);
 		if (ret < 0) {
-			usernic_error("Failed to open \"%s\": %s\n", args.pid, strerror(errno));
+			CMD_SYSERROR("Failed to open \"%s\"\n", args.pid);
 			close(netns_fd);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
+
 		close(netns_fd);
 		netns_fd = ret;
 	}
 
 	if (!create_db_dir(LXC_USERNIC_DB)) {
 		usernic_error("%s", "Failed to create directory for db file\n");
+
 		if (netns_fd >= 0)
 			close(netns_fd);
-		exit(EXIT_FAILURE);
+
+		_exit(EXIT_FAILURE);
 	}
 
 	fd = open_and_lock(LXC_USERNIC_DB);
 	if (fd < 0) {
 		usernic_error("Failed to lock %s\n", LXC_USERNIC_DB);
+
 		if (netns_fd >= 0)
 			close(netns_fd);
-		exit(EXIT_FAILURE);
+
+		_exit(EXIT_FAILURE);
 	}
 
 	if (request == LXC_USERNIC_CREATE) {
 		if (!may_access_netns(pid)) {
 			usernic_error("User %s may not modify netns for pid %d\n", me, pid);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 	} else if (request == LXC_USERNIC_DELETE) {
 		bool has_priv;
+
 		has_priv = is_privileged_over_netns(netns_fd);
 		close(netns_fd);
 		if (!has_priv) {
 			usernic_error("%s", "Process is not privileged over "
-					    "network namespace\n");
-			exit(EXIT_FAILURE);
+			              "network namespace\n");
+			_exit(EXIT_FAILURE);
 		}
 	}
 
@@ -1258,10 +1247,10 @@ int main(int argc, char *argv[])
 
 		if (!is_ovs_bridge(args.link)) {
 			usernic_error("%s", "Deletion of non ovs type network "
-					    "devices not implemented\n");
+			              "devices not implemented\n");
 			close(fd);
 			free_alloted(&alloted);
-			exit(EXIT_FAILURE);
+			_exit(EXIT_FAILURE);
 		}
 
 		/* Check whether the network device we are supposed to delete
@@ -1278,29 +1267,31 @@ int main(int argc, char *argv[])
 
 		if (!found_nicname) {
 			usernic_error("Caller is not allowed to delete network "
-				      "device \"%s\"\n", args.veth_name);
-			exit(EXIT_FAILURE);
+			              "device \"%s\"\n", args.veth_name);
+			_exit(EXIT_FAILURE);
 		}
 
 		ret = lxc_ovs_delete_port(args.link, args.veth_name);
 		if (ret < 0) {
 			usernic_error("Failed to remove port \"%s\" from "
-				      "openvswitch bridge \"%s\"",
-				      args.veth_name, args.link);
-			exit(EXIT_FAILURE);
+			              "openvswitch bridge \"%s\"",
+			              args.veth_name, args.link);
+			_exit(EXIT_FAILURE);
 		}
 
-		exit(EXIT_SUCCESS);
+		_exit(EXIT_SUCCESS);
 	}
+
 	if (n > 0)
 		nicname = get_nic_if_avail(fd, alloted, pid, args.type,
 					   args.link, n, &cnic);
 
 	close(fd);
 	free_alloted(&alloted);
+
 	if (!nicname) {
 		usernic_error("%s", "Quota reached\n");
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	/* Now rename the link. */
@@ -1308,19 +1299,21 @@ int main(int argc, char *argv[])
 					  &container_veth_ifidx);
 	if (!newname) {
 		usernic_error("%s", "Failed to rename the link\n");
+
 		ret = lxc_netdev_delete_by_name(cnic);
 		if (ret < 0)
 			usernic_error("Failed to delete \"%s\"\n", cnic);
+
 		free(nicname);
-		exit(EXIT_FAILURE);
+		_exit(EXIT_FAILURE);
 	}
 
 	host_veth_ifidx = if_nametoindex(nicname);
 	if (!host_veth_ifidx) {
 		free(newname);
 		free(nicname);
-		usernic_error("Failed to get netdev index: %s\n", strerror(errno));
-		exit(EXIT_FAILURE);
+		CMD_SYSERROR("Failed to get netdev index\n");
+		_exit(EXIT_FAILURE);
 	}
 
 	/* Write names of veth pairs and their ifindeces to stout:
@@ -1330,5 +1323,7 @@ int main(int argc, char *argv[])
 		host_veth_ifidx);
 	free(newname);
 	free(nicname);
-	exit(EXIT_SUCCESS);
+
+	fflush(stdout);
+	_exit(EXIT_SUCCESS);
 }