utils: parse_byte_size_string()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/utils.c

@@ -47,6 +47,7 @@
 #include "log.h"
 #include "lxclock.h"
 #include "namespace.h"
+#include "parse.h"
 #include "utils.h"
 
 #ifndef PR_SET_MM
@@ -2451,3 +2452,69 @@ uint64_t lxc_getpagesize(void)
 
 	return pgsz;
 }
+
+int parse_byte_size_string(const char *s, int64_t *converted)
+{
+	int ret, suffix_len;
+	long long int conv;
+	int64_t mltpl, overflow;
+	char *end;
+	char dup[LXC_NUMSTRLEN64 + 2];
+	char suffix[3];
+
+	if (!s || !strcmp(s, ""))
+		return -EINVAL;
+
+	end = stpncpy(dup, s, sizeof(dup));
+	if (*end != '\0')
+		return -EINVAL;
+
+	if (isdigit(*(end - 1)))
+		suffix_len = 0;
+	else if (isalpha(*(end - 1)))
+		suffix_len = 1;
+	else
+		return -EINVAL;
+
+	if ((end - 2) == dup && !isdigit(*(end - 2)))
+		return -EINVAL;
+
+	if (isalpha(*(end - 2))) {
+		if (suffix_len == 1)
+			suffix_len++;
+		else
+			return -EINVAL;
+	}
+
+	if (suffix_len > 0) {
+		memcpy(suffix, end - suffix_len, suffix_len);
+		*(suffix + suffix_len) = '\0';
+		*(end - suffix_len) = '\0';
+	}
+	dup[lxc_char_right_gc(dup, strlen(dup))] = '\0';
+
+	ret = lxc_safe_long_long(dup, &conv);
+	if (ret < 0)
+		return -ret;
+
+	if (suffix_len != 2) {
+		*converted = conv;
+		return 0;
+	}
+
+	if (!strcmp(suffix, "kB"))
+		mltpl = 1024;
+	else if (!strcmp(suffix, "MB"))
+		mltpl = 1024 * 1024;
+	else if (!strcmp(suffix, "GB"))
+		mltpl = 1024 * 1024 * 1024;
+	else
+		return -EINVAL;
+
+	overflow = conv * mltpl;
+	if (conv != 0 && (overflow / conv) != mltpl)
+		return -ERANGE;
+
+	*converted = overflow;
+	return 0;
+}

src/lxc/utils.h

@@ -421,6 +421,8 @@ extern int lxc_safe_int(const char *numstr, int *converted);
 extern int lxc_safe_long(const char *numstr, long int *converted);
 extern int lxc_safe_long_long(const char *numstr, long long int *converted);
 extern int lxc_safe_ulong(const char *numstr, unsigned long *converted);
+/* Handles B, kb, MB, GB. Detects overflows and reports -ERANGE. */
+extern int parse_byte_size_string(const char *s, int64_t *converted);
 
 /* Switch to a new uid and gid. */
 extern int lxc_switch_uid_gid(uid_t uid, gid_t gid);

src/tests/lxc-test-utils.c

@@ -380,6 +380,88 @@ void test_lxc_string_in_array(void)
 	lxc_test_assert_abort(lxc_string_in_array("XYZ", (const char *[]){"BERTA", "ARQWE(9", "C8Zhkd", "7U", "XYZ", "UOIZ9", "=)()", NULL}));
 }
 
+void test_parse_byte_size_string(void)
+{
+	int ret;
+	int64_t n;
+
+	ret = parse_byte_size_string("0", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 0)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 ", &n);
+	if (ret == 0)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1B", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1kB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1024)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1MB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1048576)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1GB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1073741824)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1TB", &n);
+	if (ret == 0)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 B", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 kB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1024)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 MB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1048576)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 GB", &n);
+	if (ret < 0)
+		exit(EXIT_FAILURE);
+	if (n != 1073741824)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("1 TB", &n);
+	if (ret == 0)
+		exit(EXIT_FAILURE);
+
+	ret = parse_byte_size_string("asdf", &n);
+	if (ret == 0)
+		exit(EXIT_FAILURE);
+}
+
 int main(int argc, char *argv[])
 {
 	test_lxc_string_replace();
@@ -389,6 +471,7 @@ int main(int argc, char *argv[])
 	test_lxc_safe_uint();
 	test_lxc_safe_int();
 	test_lxc_safe_long();
+	test_parse_byte_size_string();
 
 	exit(EXIT_SUCCESS);
 }