helpers: Check for trailing characters in strtoi_err

Besides checking for overflow, also checks if the number in the string
doesn't have any trailing character. For example "123abc" will return
an error and "123 abc" won't.

Also:
 - Don't return EOVERFLOW anymore, because from the user of strtoi_err
perspective it doesn't matter if the overflow is in the int size or in
the long size. I would expect the same return code.

Signed-off-by: Otavio Pontes <otavio.pontes@intel.com>

src/filedesc.c

@@ -73,7 +73,7 @@ static void foreach_open_fd(void(pf)(int, void *), void *arg)
 			continue;
 		}
 
-		err = strtoi_err(entry->d_name, &ep, &n);
+		err = strtoi_err_endptr(entry->d_name, &ep, &n);
 		if (err != 0) {
 			fprintf(stderr, "Warning: invalid fd\n");
 		}

src/globals.c

@@ -148,7 +148,7 @@ int get_version_from_path(const char *abs_path)
 
 	ret = get_value_from_path(&ret_str, abs_path, true);
 	if (ret == 0) {
-		int err = strtoi_err(ret_str, NULL, &val);
+		int err = strtoi_err(ret_str, &val);
 		free_string(&ret_str);
 
 		if (err != 0) {

src/helpers.c

@@ -22,6 +22,7 @@
  */
 
 #define _GNU_SOURCE
+#include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -602,14 +603,18 @@ out_fds:
 	return ret;
 }
 
-/* The strtol function is commonly used to convert a string to a number and
+/* strtoi_err: Safely convert and string to integer avoiding overflows.
+ *
+ * The strtol function is commonly used to convert a string to a number and
  * the result is frequently stored in an int type, but type casting a long to
- * an int can cause overflows. This function returns negative error codes based
- * on the errno table. The -ERANGE code is returned when the string is out of
- * range for strtol and the -EOVERFLOW code is returned when the long to int
- * type conversion overflows.
+ * an int can cause overflows.
+ *
+ * This function returns negative error codes based on the errno table:
+ * -ERANGE is returned when the string is out of range for int value
+ *
+ * endptr is set with the value of the first invalid character in the string.
 */
-int strtoi_err(const char *str, char **endptr, int *value)
+int strtoi_err_endptr(const char *str, char **endptr, int *value)
 {
 	long num;
 	int err;
@@ -622,10 +627,10 @@ int strtoi_err(const char *str, char **endptr, int *value)
 	 * and return an overflow error code. */
 	if (num > INT_MAX) {
 		num = INT_MAX;
-		err = -EOVERFLOW;
+		err = -ERANGE;
 	} else if (num < INT_MIN) {
 		num = INT_MIN;
-		err = -EOVERFLOW;
+		err = -ERANGE;
 	}
 
 	*value = (int)num;
@@ -633,6 +638,33 @@ int strtoi_err(const char *str, char **endptr, int *value)
 	return err;
 }
 
+/* strtoi_err: Safely convert and string to integer avoiding overflows
+ *
+ * The strtol function is commonly used to convert a string to a number and
+ * the result is frequently stored in an int type, but type casting a long to
+ * an int can cause overflows.
+ *
+ * This function returns negative error codes based on the errno table:
+ * -ERANGE is returned when the string is out of range for int value
+ * -EINVAL is returned when the string isn't a valid number or has any invalid
+ * trailing character.
+*/
+int strtoi_err(const char *str, int *value)
+{
+	char *endptr;
+	int err = strtoi_err_endptr(str, &endptr, value);
+
+	if (err) {
+		return err;
+	}
+
+	if (*endptr != '\0' && !isspace(*endptr)) {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /* Return a duplicated copy of the string using strdup().
  * Abort if there's no memory to allocate the new string.
 */
@@ -979,7 +1011,7 @@ bool on_new_format(void)
 		return false;
 	}
 
-	err = strtoi_err(ret_str, NULL, &res);
+	err = strtoi_err(ret_str, &res);
 	free_string(&ret_str);
 
 	if (err != 0) {

src/manifest.c

@@ -131,7 +131,7 @@ static struct manifest *manifest_from_file(int version, char *component, bool he
 	}
 
 	c = &line[9];
-	err = strtoi_err(c, NULL, &manifest_enc_version);
+	err = strtoi_err(c, &manifest_enc_version);
 
 	if (manifest_enc_version <= 0 || err != 0) {
 		fprintf(stderr, "Error: Loaded incompatible manifest version\n");
@@ -163,7 +163,7 @@ static struct manifest *manifest_from_file(int version, char *component, bool he
 		}
 
 		if (strncmp(line, "version:", 8) == 0) {
-			err = strtoi_err(c, NULL, &manifest_hdr_version);
+			err = strtoi_err(c, &manifest_hdr_version);
 			if (manifest_hdr_version != version || err != 0) {
 				fprintf(stderr, "Error: Loaded incompatible manifest header version\n");
 				goto err_close;
@@ -330,7 +330,7 @@ static struct manifest *manifest_from_file(int version, char *component, bool he
 			goto err;
 		}
 
-		err = strtoi_err(c, NULL, &file->last_change);
+		err = strtoi_err(c, &file->last_change);
 		if (file->last_change <= 0 || err != 0) {
 			fprintf(stderr, "Error: Loaded incompatible manifest last change\n");
 			free(file);

src/search.c

@@ -437,7 +437,7 @@ static bool parse_options(int argc, char **argv)
 
 			break;
 		case 't':
-			err = strtoi_err(optarg, NULL, &num_results);
+			err = strtoi_err(optarg, &num_results);
 			if (err != 0) {
 				fprintf(stderr, "Invalid --top argument\n\n");
 				goto err;

src/swupd.h

@@ -365,7 +365,8 @@ extern int rm_bundle_file(const char *bundle);
 extern void print_manifest_files(struct manifest *m);
 extern void swupd_deinit(void);
 extern int swupd_init(void);
-extern int strtoi_err(const char *str, char **endptr, int *value);
+extern int strtoi_err(const char *str, int *value);
+extern int strtoi_err_endptr(const char *str, char **endptr, int *value);
 extern void string_or_die(char **strp, const char *fmt, ...);
 char *strdup_or_die(const char *const str);
 extern void free_string(char **s);

src/version.c

@@ -69,7 +69,7 @@ int get_latest_version(char *v_url)
 		goto out;
 	} else {
 		tmp_version.data[tmp_version.len] = '\0';
-		err = strtoi_err(tmp_version.data, NULL, &ret);
+		err = strtoi_err(tmp_version.data, &ret);
 
 		if (err != 0) {
 			ret = -1;
@@ -123,7 +123,7 @@ int get_current_version(char *path_prefix)
 			}
 			*dest = 0;
 
-			err = strtoi_err(&line[11], NULL, &v);
+			err = strtoi_err(&line[11], &v);
 			if (err != 0) {
 				v = -1;
 			}
@@ -203,7 +203,7 @@ int read_mix_version_file(char *filename, char *path_prefix)
 			*c = '\0';
 		}
 
-		err = strtoi_err(line, NULL, &v);
+		err = strtoi_err(line, &v);
 		if (err != 0) {
 			v = -1;
 		}