Merge pull request #1256 from brauner/2016-09-06/remove_atoi

src/lxc/arguments.h

@@ -61,7 +61,7 @@ struct lxc_arguments {
 	const char *share_ns[32]; // size must be greater than LXC_NS_MAX
 
 	/* for lxc-console */
-	int ttynum;
+	unsigned int ttynum;
 	char escape;
 
 	/* for lxc-wait */

src/lxc/conf.c

@@ -2504,7 +2504,8 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
 {
 	char veth1buf[IFNAMSIZ], *veth1;
 	char veth2buf[IFNAMSIZ], *veth2;
-	int bridge_index, err, mtu = 0;
+	int bridge_index, err;
+	unsigned int mtu = 0;
 
 	if (netdev->priv.veth_attr.pair) {
 		veth1 = netdev->priv.veth_attr.pair;
@@ -2556,8 +2557,10 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
 	}
 
 	if (netdev->mtu) {
-		mtu = atoi(netdev->mtu);
-		INFO("Retrieved mtu %d", mtu);
+		if (lxc_safe_uint(netdev->mtu, &mtu) < 0)
+			WARN("Failed to parse mtu from.");
+		else
+			INFO("Retrieved mtu %d", mtu);
 	} else if (netdev->link) {
 		bridge_index = if_nametoindex(netdev->link);
 		if (bridge_index) {
@@ -2706,6 +2709,7 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
 	char peer[IFNAMSIZ];
 	int err;
 	static uint16_t vlan_cntr = 0;
+	unsigned int mtu = 0;
 
 	if (!netdev->link) {
 		ERROR("no link specified for vlan netdev");
@@ -2735,7 +2739,12 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
 	DEBUG("instantiated vlan '%s', ifindex is '%d'", " vlan1000",
 	      netdev->ifindex);
 	if (netdev->mtu) {
-		err = lxc_netdev_set_mtu(peer, atoi(netdev->mtu));
+		if (lxc_safe_uint(netdev->mtu, &mtu) < 0) {
+			ERROR("Failed to retrieve mtu from: '%d'/'%s'.",
+			      netdev->ifindex, netdev->name);
+			return -1;
+		}
+		err = lxc_netdev_set_mtu(peer, mtu);
 		if (err) {
 			ERROR("failed to set mtu '%s' for %s : %s",
 			      netdev->mtu, peer, strerror(-err));
@@ -4450,8 +4459,10 @@ void suggest_default_idmap(void)
 		p2++;
 		if (!*p2)
 			continue;
-		uid = atoi(p);
-		urange = atoi(p2);
+		if (lxc_safe_uint(p, &uid) < 0)
+			WARN("Could not parse UID.");
+		if (lxc_safe_uint(p2, &urange) < 0)
+			WARN("Could not parse UID range.");
 	}
 	fclose(f);
 
@@ -4479,8 +4490,10 @@ void suggest_default_idmap(void)
 		p2++;
 		if (!*p2)
 			continue;
-		gid = atoi(p);
-		grange = atoi(p2);
+		if (lxc_safe_uint(p, &gid) < 0)
+			WARN("Could not parse GID.");
+		if (lxc_safe_uint(p2, &grange) < 0)
+			WARN("Could not parse GID range.");
 	}
 	fclose(f);
 

src/lxc/conf.h

@@ -62,7 +62,7 @@ enum {
 struct lxc_inetdev {
 	struct in_addr addr;
 	struct in_addr bcast;
-	int prefix;
+	unsigned int prefix;
 };
 
 struct lxc_route {
@@ -80,7 +80,7 @@ struct lxc_inet6dev {
 	struct in6_addr addr;
 	struct in6_addr mcast;
 	struct in6_addr acast;
-	int prefix;
+	unsigned int prefix;
 };
 
 struct lxc_route6 {
@@ -293,8 +293,8 @@ struct saved_nic {
 struct lxc_conf {
 	int is_execute;
 	char *fstab;
-	int tty;
-	int pts;
+	unsigned int tty;
+	unsigned int pts;
 	int reboot;
 	int need_utmp_watch;
 	signed long personality;
@@ -317,7 +317,7 @@ struct lxc_conf {
 	struct lxc_list hooks[NUM_LXC_HOOKS];
 
 	char *lsm_aa_profile;
-	int lsm_aa_allow_incomplete;
+	unsigned int lsm_aa_allow_incomplete;
 	char *lsm_se_context;
 	int tmp_umount_proc;
 	char *seccomp;  // filename with the seccomp rules
@@ -325,11 +325,11 @@ struct lxc_conf {
 	scmp_filter_ctx seccomp_ctx;
 #endif
 	int maincmd_fd;
-	int autodev;  // if 1, mount and fill a /dev at start
+	unsigned int autodev;  // if 1, mount and fill a /dev at start
 	int haltsignal; // signal used to halt container
 	int rebootsignal; // signal used to reboot container
 	int stopsignal; // signal used to hard stop container
-	int kmsg;  // if 1, create /dev/kmsg symlink
+	unsigned int kmsg;  // if 1, create /dev/kmsg symlink
 	char *rcfile;	// Copy of the top level rcfile we read
 
 	// Logfile and logleve can be set in a container config file.
@@ -343,14 +343,14 @@ struct lxc_conf {
 
 	int inherit_ns_fd[LXC_NS_MAX];
 
-	int start_auto;
-	int start_delay;
+	unsigned int start_auto;
+	unsigned int start_delay;
 	int start_order;
 	struct lxc_list groups;
 	int nbd_idx;
 
 	/* unshare the mount namespace in the monitor */
-	int monitor_unshare;
+	unsigned int monitor_unshare;
 
 	/* set to true when rootfs has been setup */
 	bool rootfs_setup;
@@ -377,7 +377,7 @@ struct lxc_conf {
 	gid_t init_gid;
 
 	/* indicator if the container will be destroyed on shutdown */
-	int ephemeral;
+	unsigned int ephemeral;
 
 	/* The facility to pass to syslog. Let's users establish as what type of
 	 * program liblxc is supposed to write to the syslog. */

src/lxc/confile.c

@@ -853,8 +853,12 @@ static int config_network_ipv4(const char *key, const char *value,
 	}
 
 	/* no prefix specified, determine it from the network class */
-	inetdev->prefix = prefix ? atoi(prefix) :
-		config_ip_prefix(&inetdev->addr);
+	if (prefix) {
+		if (lxc_safe_uint(prefix, &inetdev->prefix) < 0)
+			return -1;
+	} else {
+		inetdev->prefix = config_ip_prefix(&inetdev->addr);
+	}
 
 	/* if no broadcast address, let compute one from the
 	 * prefix and address
@@ -952,7 +956,8 @@ static int config_network_ipv6(const char *key, const char *value,
 	if (slash) {
 		*slash = '\0';
 		netmask = slash + 1;
-		inet6dev->prefix = atoi(netmask);
+		if (lxc_safe_uint(netmask, &inet6dev->prefix) < 0)
+			return -1;
 	}
 
 	if (!inet_pton(AF_INET6, valdup, &inet6dev->addr)) {
@@ -1060,14 +1065,24 @@ static int config_init_cmd(const char *key, const char *value,
 static int config_init_uid(const char *key, const char *value,
 				 struct lxc_conf *lxc_conf)
 {
-	lxc_conf->init_uid = atoi(value);
+	unsigned int init_uid;
+
+	if (lxc_safe_uint(value, &init_uid) < 0)
+		return -1;
+	lxc_conf->init_uid = init_uid;
+
 	return 0;
 }
 
 static int config_init_gid(const char *key, const char *value,
 				 struct lxc_conf *lxc_conf)
 {
-	lxc_conf->init_gid = atoi(value);
+	unsigned int init_gid;
+
+	if (lxc_safe_uint(value, &init_gid) < 0)
+		return -1;
+	lxc_conf->init_gid = init_gid;
+
 	return 0;
 }
 
@@ -1127,9 +1142,8 @@ static int config_personality(const char *key, const char *value,
 static int config_pts(const char *key, const char *value,
 		      struct lxc_conf *lxc_conf)
 {
-	int maxpts = atoi(value);
-
-	lxc_conf->pts = maxpts;
+	if (lxc_safe_uint(value, &lxc_conf->pts) < 0)
+		return -1;
 
 	return 0;
 }
@@ -1138,15 +1152,20 @@ static int config_start(const char *key, const char *value,
 		      struct lxc_conf *lxc_conf)
 {
 	if(strcmp(key, "lxc.start.auto") == 0) {
-		lxc_conf->start_auto = atoi(value);
+		if (lxc_safe_uint(value, &lxc_conf->start_auto) < 0)
+			return -1;
+		if (lxc_conf->start_auto > 1)
+			return -1;
 		return 0;
 	}
 	else if (strcmp(key, "lxc.start.delay") == 0) {
-		lxc_conf->start_delay = atoi(value);
+		if (lxc_safe_uint(value, &lxc_conf->start_delay) < 0)
+			return -1;
 		return 0;
 	}
 	else if (strcmp(key, "lxc.start.order") == 0) {
-		lxc_conf->start_order = atoi(value);
+		if (lxc_safe_int(value, &lxc_conf->start_order) < 0)
+			return -1;
 		return 0;
 	}
 	SYSERROR("Unknown key: %s", key);
@@ -1157,7 +1176,8 @@ static int config_monitor(const char *key, const char *value,
 			  struct lxc_conf *lxc_conf)
 {
 	if(strcmp(key, "lxc.monitor.unshare") == 0) {
-		lxc_conf->monitor_unshare = atoi(value);
+		if (lxc_safe_uint(value, &lxc_conf->monitor_unshare) < 0)
+			return -1;
 		return 0;
 	}
 	SYSERROR("Unknown key: %s", key);
@@ -1240,9 +1260,8 @@ freak_out:
 static int config_tty(const char *key, const char *value,
 		      struct lxc_conf *lxc_conf)
 {
-	int nbtty = atoi(value);
-
-	lxc_conf->tty = nbtty;
+	if (lxc_safe_uint(value, &lxc_conf->tty) < 0)
+		return -1;
 
 	return 0;
 }
@@ -1256,9 +1275,11 @@ static int config_ttydir(const char *key, const char *value,
 static int config_kmsg(const char *key, const char *value,
 			  struct lxc_conf *lxc_conf)
 {
-	int v = atoi(value);
+	if (lxc_safe_uint(value, &lxc_conf->kmsg) < 0)
+		return -1;
 
-	lxc_conf->kmsg = v;
+	if (lxc_conf->kmsg > 1)
+		return -1;
 
 	return 0;
 }
@@ -1272,9 +1293,13 @@ static int config_lsm_aa_profile(const char *key, const char *value,
 static int config_lsm_aa_incomplete(const char *key, const char *value,
 				 struct lxc_conf *lxc_conf)
 {
-	int v = atoi(value);
+	if (lxc_safe_uint(value, &lxc_conf->lsm_aa_allow_incomplete) < 0)
+		return -1;
 
-	lxc_conf->lsm_aa_allow_incomplete = v == 1 ? 1 : 0;
+	if (lxc_conf->lsm_aa_allow_incomplete > 1) {
+		ERROR("Wrong value for lxc.lsm_aa_allow_incomplete. Can only be set to 0 or 1");
+		return -1;
+	}
 
 	return 0;
 }
@@ -1306,10 +1331,12 @@ static int config_loglevel(const char *key, const char *value,
 	if (!value || strlen(value) == 0)
 		return 0;
 
-	if (value[0] >= '0' && value[0] <= '9')
-		newlevel = atoi(value);
-	else
+	if (value[0] >= '0' && value[0] <= '9') {
+		if (lxc_safe_int(value, &newlevel) < 0)
+			return -1;
+	} else {
 		newlevel = lxc_log_priority_to_int(value);
+	}
 	// store these values in the lxc_conf, and then try to set for
 	// actual current logging.
 	lxc_conf->loglevel = newlevel;
@@ -1319,9 +1346,13 @@ static int config_loglevel(const char *key, const char *value,
 static int config_autodev(const char *key, const char *value,
 			  struct lxc_conf *lxc_conf)
 {
-	int v = atoi(value);
+	if (lxc_safe_uint(value, &lxc_conf->autodev) < 0)
+		return -1;
 
-	lxc_conf->autodev = v;
+	if (lxc_conf->autodev > 1) {
+		ERROR("Wrong value for lxc.autodev. Can only be set to 0 or 1");
+		return -1;
+	}
 
 	return 0;
 }
@@ -2933,13 +2964,12 @@ bool network_new_hwaddrs(struct lxc_conf *conf)
 static int config_ephemeral(const char *key, const char *value,
 			    struct lxc_conf *lxc_conf)
 {
-	int v = atoi(value);
+	if (lxc_safe_uint(value, &lxc_conf->ephemeral) < 0)
+		return -1;
 
-	if (v != 0 && v != 1) {
+	if (lxc_conf->ephemeral > 1) {
 		ERROR("Wrong value for lxc.ephemeral. Can only be set to 0 or 1");
 		return -1;
-	} else {
-		lxc_conf->ephemeral = v;
 	}
 
 	return 0;
@@ -2951,7 +2981,7 @@ static int config_syslog(const char *key, const char *value,
 	int facility;
 	facility = lxc_syslog_priority_to_int(value);
 	if (facility == -EINVAL) {
-		ERROR("Wrong value for lxc.syslog");
+		ERROR("Wrong value for lxc.syslog.");
 		return -1;
 	}
 
@@ -2962,12 +2992,16 @@ static int config_syslog(const char *key, const char *value,
 static int config_no_new_privs(const char *key, const char *value,
 				    struct lxc_conf *lxc_conf)
 {
-	int v = atoi(value);
+	unsigned int v;
+
+	if (lxc_safe_uint(value, &v) < 0)
+		return -1;
 
-	if (v != 0 && v != 1) {
+	if (v > 1) {
 		ERROR("Wrong value for lxc.no_new_privs. Can only be set to 0 or 1");
 		return -1;
 	}
+
 	lxc_conf->no_new_privs = v ? true : false;
 
 	return 0;

src/lxc/lxc_monitord.c

@@ -362,14 +362,15 @@ int main(int argc, char *argv[])
 	ret = snprintf(logpath, sizeof(logpath), "%s/lxc-monitord.log",
 		       (strcmp(LXCPATH, lxcpath) ? lxcpath : LOGPATH ) );
 	if (ret < 0 || ret >= sizeof(logpath))
-		return EXIT_FAILURE;
+		exit(EXIT_FAILURE);
 
 	ret = lxc_log_init(NULL, logpath, "NOTICE", "lxc-monitord", 0, lxcpath);
 	if (ret)
 		INFO("Failed to open log file %s, log will be lost", lxcpath);
 	lxc_log_options_no_override();
 
-	pipefd = atoi(argv[2]);
+	if (lxc_safe_int(argv[2], &pipefd) < 0)
+		exit(EXIT_FAILURE);
 
 	if (sigfillset(&mask) ||
 	    sigdelset(&mask, SIGILL)  ||
@@ -378,7 +379,7 @@ int main(int argc, char *argv[])
 	    sigdelset(&mask, SIGTERM) ||
 	    sigprocmask(SIG_BLOCK, &mask, NULL)) {
 		SYSERROR("failed to set signal mask");
-		return 1;
+		exit(EXIT_FAILURE);
 	}
 
 	signal(SIGILL,  lxc_monitord_sig_handler);
@@ -428,7 +429,5 @@ int main(int argc, char *argv[])
 	ret = EXIT_SUCCESS;
 	NOTICE("monitor exiting");
 out:
-	if (ret == 0)
-		return 0;
-	return 1;
+	exit(ret);
 }

src/lxc/start.c

@@ -223,7 +223,10 @@ restart:
 		if (!strcmp(direntp->d_name, ".."))
 			continue;
 
-		fd = atoi(direntp->d_name);
+		if (lxc_safe_int(direntp->d_name, &fd) < 0) {
+			INFO("Could not parse file descriptor for: %s", direntp->d_name);
+			continue;
+		}
 
 		if (fd == fddir || fd == lxc_log_fd || fd == fd_to_ignore)
 			continue;

src/lxc/tools/lxc_autostart.c

@@ -26,6 +26,7 @@
 #include "arguments.h"
 #include "list.h"
 #include "log.h"
+#include "utils.h"
 
 lxc_log_define(lxc_autostart_ui, lxc);
 static struct lxc_list *accumulate_list(char *input, char *delimiter, struct lxc_list *str_list);
@@ -35,14 +36,31 @@ struct lxc_list *cmd_groups_list = NULL;
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 'k': args->hardstop = 1; break;
-	case 'L': args->list = 1; break;
-	case 'r': args->reboot = 1; break;
-	case 's': args->shutdown = 1; break;
-	case 'a': args->all = 1; break;
-	case 'A': args->ignore_auto = 1; break;
-	case 'g': cmd_groups_list = accumulate_list( arg, ",", cmd_groups_list); break;
-	case 't': args->timeout = atoi(arg); break;
+	case 'k':
+		args->hardstop = 1;
+		break;
+	case 'L':
+		args->list = 1;
+		break;
+	case 'r':
+		args->reboot = 1;
+		break;
+	case 's':
+		args->shutdown = 1;
+		break;
+	case 'a':
+		args->all = 1;
+		break;
+	case 'A':
+		args->ignore_auto = 1;
+		break;
+	case 'g':
+		cmd_groups_list = accumulate_list(arg, ",", cmd_groups_list);
+		break;
+	case 't':
+		if (lxc_safe_long(arg, &args->timeout) < 0)
+			return -1;
+		break;
 	}
 	return 0;
 }
@@ -290,7 +308,9 @@ static int get_config_integer(struct lxc_container *c, char *key) {
 		return 0;
 	}
 
-	ret = atoi(value);
+	if (lxc_safe_int(value, &ret) < 0)
+		DEBUG("Could not parse config item.");
+
 	free(value);
 
 	return ret;

src/lxc/tools/lxc_console.c

@@ -22,29 +22,29 @@
  */
 
 #define _GNU_SOURCE
-#include <stdio.h>
-#undef _GNU_SOURCE
-#include <stdlib.h>
 #include <errno.h>
-#include <string.h>
 #include <fcntl.h>
-#include <unistd.h>
-#include <signal.h>
 #include <libgen.h>
 #include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
 #include <sys/param.h>
-#include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/ioctl.h>
+#include <sys/types.h>
 
 #include <lxc/lxccontainer.h>
 
+#include "arguments.h"
+#include "commands.h"
 #include "error.h"
-#include "lxc.h"
 #include "log.h"
+#include "lxc.h"
 #include "mainloop.h"
-#include "arguments.h"
-#include "commands.h"
+#include "utils.h"
 
 lxc_log_define(lxc_console_ui, lxc);
 
@@ -58,8 +58,13 @@ static char etoc(const char *expr)
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 't': args->ttynum = atoi(arg); break;
-	case 'e': args->escape = etoc(arg); break;
+	case 't':
+		if (lxc_safe_uint(arg, &args->ttynum) < 0)
+			return -1;
+		break;
+	case 'e':
+		args->escape = etoc(arg);
+		break;
 	}
 	return 0;
 }

src/lxc/tools/lxc_execute.c

@@ -58,10 +58,19 @@ static int my_checker(const struct lxc_arguments* args)
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 'f': args->rcfile = arg; break;
-	case 's': return lxc_config_define_add(&defines, arg); break;
-	case 'u': args->uid = atoi(arg); break;
-	case 'g': args->gid = atoi(arg);
+	case 'f':
+		args->rcfile = arg;
+		break;
+	case 's':
+		return lxc_config_define_add(&defines, arg);
+		break;
+	case 'u':
+		if (lxc_safe_uint(arg, &args->uid) < 0)
+			return -1;
+		break;
+	case 'g':
+		if (lxc_safe_uint(arg, &args->gid) < 0)
+			return -1;
 	}
 	return 0;
 }

src/lxc/tools/lxc_ls.c

@@ -459,8 +459,14 @@ static int ls_get(struct ls **m, size_t *size, const struct lxc_arguments *args,
 				goto put_and_next;
 
 			tmp = ls_get_config_item(c, "lxc.start.auto", running);
-			if (tmp)
-				l->autostart = atoi(tmp);
+			if (tmp) {
+				unsigned int astart = 0;
+				if (lxc_safe_uint(tmp, &astart) < 0)
+					WARN("Could not parse value for 'lxc.start.auto'.");
+				if (astart > 1)
+					DEBUG("Wrong value for 'lxc.start.auto = %d'.", astart);
+				l->autostart = astart == 1 ? true : false;
+			}
 			free(tmp);
 
 			if (running) {

src/lxc/tools/lxc_stop.c

@@ -38,15 +38,28 @@
 
 lxc_log_define(lxc_stop_ui, lxc);
 
-static int my_parser(struct lxc_arguments* args, int c, char* arg)
+static int my_parser(struct lxc_arguments *args, int c, char *arg)
 {
 	switch (c) {
-	case 'r': args->reboot = 1; break;
-	case 'W': args->nowait = 1; break;
-	case 't': args->timeout = atoi(arg); break;
-	case 'k': args->hardstop = 1; break;
-	case OPT_NO_LOCK: args->nolock = 1; break;
-	case OPT_NO_KILL: args->nokill = 1; break;
+	case 'r':
+		args->reboot = 1;
+		break;
+	case 'W':
+		args->nowait = 1;
+		break;
+	case 't':
+		if (lxc_safe_long(arg, &args->timeout) < 0)
+			return -1;
+		break;
+	case 'k':
+		args->hardstop = 1;
+		break;
+	case OPT_NO_LOCK:
+		args->nolock = 1;
+		break;
+	case OPT_NO_KILL:
+		args->nokill = 1;
+		break;
 	}
 	return 0;
 }
@@ -155,17 +168,14 @@ int main(int argc, char *argv[])
 
 	/* Set default timeout */
 	if (my_args.timeout == -2) {
-		if (my_args.hardstop) {
+		if (my_args.hardstop)
 			my_args.timeout = 0;
-		}
-		else {
+		else
 			my_args.timeout = 60;
-		}
 	}
 
-	if (my_args.nowait) {
+	if (my_args.nowait)
 		my_args.timeout = 0;
-	}
 
 	/* some checks */
 	if (!my_args.hardstop && my_args.timeout < -1) {

src/lxc/tools/lxc_top.c

@@ -74,9 +74,16 @@ static int ct_alloc_cnt = 0;
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 'd': delay = atoi(arg); break;
-	case 's': sort_by = arg[0]; break;
-	case 'r': sort_reverse = 1; break;
+	case 'd':
+		if (lxc_safe_int(arg, &delay) < 0)
+			return -1;
+		break;
+	case 's':
+		sort_by = arg[0];
+		break;
+	case 'r':
+		sort_reverse = 1;
+		break;
 	}
 	return 0;
 }

src/lxc/utils.c

@@ -1766,7 +1766,7 @@ int mount_proc_if_needed(const char *rootfs)
 {
 	char path[MAXPATHLEN];
 	char link[20];
-	int linklen, ret;
+	int link_to_pid, linklen, ret;
 	int mypid;
 
 	ret = snprintf(path, MAXPATHLEN, "%s/proc/self", rootfs);
@@ -1785,7 +1785,9 @@ int mount_proc_if_needed(const char *rootfs)
 	}
 	if (linklen < 0) /* /proc not mounted */
 		goto domount;
-	if (atoi(link) != mypid) {
+	if (lxc_safe_int(link, &link_to_pid) < 0)
+		return -1;
+	if (link_to_pid != mypid) {
 		/* wrong /procs mounted */
 		umount2(path, MNT_DETACH); /* ignore failure */
 		goto domount;
@@ -1988,3 +1990,63 @@ int lxc_preserve_ns(const int pid, const char *ns)
 
 	return open(path, O_RDONLY | O_CLOEXEC);
 }
+
+int lxc_safe_uint(const char *numstr, unsigned int *converted)
+{
+	char *err = NULL;
+	unsigned long int uli;
+
+	errno = 0;
+	uli = strtoul(numstr, &err, 0);
+	if (errno > 0)
+		return -errno;
+
+	if (!err || err == numstr || *err != '\0')
+		return -EINVAL;
+
+	if (uli > UINT_MAX)
+		return -ERANGE;
+
+	*converted = (unsigned int)uli;
+	return 0;
+}
+
+int lxc_safe_int(const char *numstr, int *converted)
+{
+	char *err = NULL;
+	signed long int sli;
+
+	errno = 0;
+	sli = strtol(numstr, &err, 0);
+	if (errno > 0)
+		return -errno;
+
+	if (!err || err == numstr || *err != '\0')
+		return -EINVAL;
+
+	if (sli > INT_MAX)
+		return -ERANGE;
+
+	*converted = (int)sli;
+	return 0;
+}
+
+int lxc_safe_long(const char *numstr, long int *converted)
+{
+	char *err = NULL;
+	signed long int sli;
+
+	errno = 0;
+	sli = strtol(numstr, &err, 0);
+	if (errno > 0)
+		return -errno;
+
+	if (!err || err == numstr || *err != '\0')
+		return -EINVAL;
+
+	if (sli > LONG_MAX)
+		return -ERANGE;
+
+	*converted = sli;
+	return 0;
+}

src/lxc/utils.h

@@ -316,4 +316,10 @@ int lxc_preserve_ns(const int pid, const char *ns);
 
 /* Check whether a signal is blocked by a process. */
 bool task_blocking_signal(pid_t pid, int signal);
+
+/* Helper functions to parse numbers. */
+int lxc_safe_uint(const char *numstr, unsigned int *converted);
+int lxc_safe_int(const char *numstr, int *converted);
+int lxc_safe_long(const char *numstr, long int *converted);
+
 #endif /* __LXC_UTILS_H */

src/tests/lxc-test-utils.c

@@ -22,8 +22,11 @@
  */
 
 #define _GNU_SOURCE
+#define __STDC_FORMAT_MACROS
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
 #include <sched.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -222,6 +225,100 @@ non_test_error:
 	exit(fret);
 }
 
+void test_lxc_safe_uint(void)
+{
+	int ret;
+	unsigned int n;
+	size_t len = /* 2^64 = 21 - 1 */ 21;
+	char uint_max[len];
+
+	ret = snprintf(uint_max, len, "%lu", (unsigned long)UINT_MAX + 1);
+	if (ret < 0 || (size_t)ret >= len) {
+		lxc_error("%s\n", "Failed to create string via snprintf().");
+		exit(EXIT_FAILURE);
+	}
+
+	lxc_test_assert_abort((0 == lxc_safe_uint("1234345", &n)) && n == 1234345);
+	lxc_test_assert_abort((0 == lxc_safe_uint("   345", &n)) && n == 345);
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("   g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("   3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("   345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("g345   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("3g45   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("345g   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_uint("   g345", &n)));
+	lxc_test_assert_abort((-ERANGE == lxc_safe_uint(uint_max, &n)));
+}
+
+void test_lxc_safe_int(void)
+{
+	int ret;
+	signed int n;
+	size_t len = /* 2^64 = 21 - 1 */ 21;
+	char int_max[len];
+
+	ret = snprintf(int_max, len, "%ld", (signed long)INT_MAX + 1);
+	if (ret < 0 || (size_t)ret >= len) {
+		lxc_error("%s\n", "Failed to create string via snprintf().");
+		exit(EXIT_FAILURE);
+	}
+
+	lxc_test_assert_abort((0 == lxc_safe_int("1234345", &n)) && n == 1234345);
+	lxc_test_assert_abort((0 == lxc_safe_int("   345", &n)) && n == 345);
+	lxc_test_assert_abort((0 == lxc_safe_int("-1234345", &n)) && n == -1234345);
+	lxc_test_assert_abort((0 == lxc_safe_int("   -345", &n)) && n == -345);
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("   g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("   3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("   345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("g345   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("3g45   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("345g   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_int("   g345", &n)));
+	lxc_test_assert_abort((-ERANGE == lxc_safe_int(int_max, &n)));
+}
+
+void test_lxc_safe_long(void)
+{
+	int ret;
+	signed long int n;
+	size_t len = /* 2^64 = 21 - 1 */ 21;
+	char long_max[len];
+
+	ret = snprintf(long_max, len, "%lld", LLONG_MAX);
+	if (ret < 0 || (size_t)ret >= len) {
+		lxc_error("%s\n", "Failed to create string via snprintf().");
+		exit(EXIT_FAILURE);
+	}
+
+	lxc_test_assert_abort((0 == lxc_safe_long("1234345", &n)) && n == 1234345);
+	lxc_test_assert_abort((0 == lxc_safe_long("   345", &n)) && n == 345);
+	lxc_test_assert_abort((0 == lxc_safe_long("-1234345", &n)) && n == -1234345);
+	lxc_test_assert_abort((0 == lxc_safe_long("   -345", &n)) && n == -345);
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("   g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("   3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("   345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("g345", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("3g45", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("345g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("g345   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("3g45   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("345g   ", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("g", &n)));
+	lxc_test_assert_abort((-EINVAL == lxc_safe_long("   g345", &n)));
+	if (LONG_MAX != LLONG_MAX)
+		lxc_test_assert_abort((-ERANGE == lxc_safe_long(long_max, &n)));
+	else
+		lxc_test_assert_abort((0 == lxc_safe_long(long_max, &n)) && n == LONG_MAX);
+}
+
 void test_lxc_string_replace(void)
 {
 	char *s;
@@ -280,6 +377,9 @@ int main(int argc, char *argv[])
 	test_lxc_string_in_array();
 	test_lxc_deslashify();
 	test_detect_ramfs_rootfs();
+	test_lxc_safe_uint();
+	test_lxc_safe_int();
+	test_lxc_safe_long();
 
 	exit(EXIT_SUCCESS);
 }