parse-util: Introduce new parse_range function

This function will be useful for CPUAffinity settings that involve
ranges of CPUs.

Make it generic and include test coverage to prevent regressions.

3 files changed, 220 insertions, 0 deletions

diff --git a/src/basic/parse-util.c b/src/basic/parse-util.c
index 2437fee60c..1ee5783680 100644
--- a/src/basic/parse-util.c
+++ b/src/basic/parse-util.c
@@ -19,6 +19,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "alloc-util.h"
+#include "extract-word.h"
 #include "parse-util.h"
 #include "string-util.h"
 #include "util.h"
@@ -207,6 +209,43 @@ int parse_size(const char *t, uint64_t base, uint64_t *size) {
         return 0;
 }
 
+int parse_range(const char *t, unsigned *lower, unsigned *upper) {
+        _cleanup_free_ char *word = NULL;
+        unsigned l, u;
+        int r;
+
+        assert(lower);
+        assert(upper);
+
+        /* Extract the lower bound. */
+        r = extract_first_word(&t, &word, "-", EXTRACT_DONT_COALESCE_SEPARATORS);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -EINVAL;
+
+        r = safe_atou(word, &l);
+        if (r < 0)
+                return r;
+
+        /* Check for the upper bound and extract it if needed */
+        if (!t)
+                /* Single number with no dashes. */
+                u = l;
+        else if (!*t)
+                /* Trailing dash is an error. */
+                return -EINVAL;
+        else {
+                r = safe_atou(t, &u);
+                if (r < 0)
+                        return r;
+        }
+
+        *lower = l;
+        *upper = u;
+        return 0;
+}
+
 char *format_bytes(char *buf, size_t l, uint64_t t) {
         unsigned i;
 
diff --git a/src/basic/parse-util.h b/src/basic/parse-util.h
index 72a619c38f..0e56848e26 100644
--- a/src/basic/parse-util.h
+++ b/src/basic/parse-util.h
@@ -33,6 +33,7 @@ int parse_pid(const char *s, pid_t* ret_pid);
 int parse_mode(const char *s, mode_t *ret);
 
 int parse_size(const char *t, uint64_t base, uint64_t *size);
+int parse_range(const char *t, unsigned *lower, unsigned *upper);
 
 #define FORMAT_BYTES_MAX 8
 char *format_bytes(char *buf, size_t l, uint64_t t);
diff --git a/src/test/test-util.c b/src/test/test-util.c
index b0eb77592e..5d01d06523 100644
--- a/src/test/test-util.c
+++ b/src/test/test-util.c
@@ -979,6 +979,185 @@ static void test_parse_size(void) {
         assert_se(parse_size("-10B 20K", 1024, &bytes) == -ERANGE);
 }
 
+static void test_parse_range(void) {
+        unsigned lower, upper;
+
+        /* Successful cases */
+        assert_se(parse_range("111", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 111);
+
+        assert_se(parse_range("111-123", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 123);
+
+        assert_se(parse_range("123-111", &lower, &upper) == 0);
+        assert_se(lower == 123);
+        assert_se(upper == 111);
+
+        assert_se(parse_range("123-123", &lower, &upper) == 0);
+        assert_se(lower == 123);
+        assert_se(upper == 123);
+
+        assert_se(parse_range("0", &lower, &upper) == 0);
+        assert_se(lower == 0);
+        assert_se(upper == 0);
+
+        assert_se(parse_range("0-15", &lower, &upper) == 0);
+        assert_se(lower == 0);
+        assert_se(upper == 15);
+
+        assert_se(parse_range("15-0", &lower, &upper) == 0);
+        assert_se(lower == 15);
+        assert_se(upper == 0);
+
+        assert_se(parse_range("128-65535", &lower, &upper) == 0);
+        assert_se(lower == 128);
+        assert_se(upper == 65535);
+
+        assert_se(parse_range("1024-4294967295", &lower, &upper) == 0);
+        assert_se(lower == 1024);
+        assert_se(upper == 4294967295);
+
+        /* Leading whitespace is acceptable */
+        assert_se(parse_range(" 111", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 111);
+
+        assert_se(parse_range(" 111-123", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 123);
+
+        assert_se(parse_range("111- 123", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 123);
+
+        assert_se(parse_range("\t111-\t123", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 123);
+
+        assert_se(parse_range(" \t 111- \t 123", &lower, &upper) == 0);
+        assert_se(lower == 111);
+        assert_se(upper == 123);
+
+        /* Error cases, make sure they fail as expected */
+        lower = upper = 9999;
+        assert_se(parse_range("111garbage", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("garbage111", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("garbage", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123garbage", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111garbage-123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* Empty string */
+        lower = upper = 9999;
+        assert_se(parse_range("", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* 111--123 will pass -123 to safe_atou which returns -ERANGE for negative */
+        assert_se(parse_range("111--123", &lower, &upper) == -ERANGE);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("-111-123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123-", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111.4-123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123.4", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111,4-123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123,4", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* Error on trailing dash */
+        assert_se(parse_range("111-", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123-", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111--", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111- ", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* Whitespace is not a separator */
+        assert_se(parse_range("111 123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111\t123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111 \t 123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* Trailing whitespace is invalid (from safe_atou) */
+        assert_se(parse_range("111 ", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111-123 ", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111 -123", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111 -123 ", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111\t-123\t", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        assert_se(parse_range("111 \t -123 \t ", &lower, &upper) == -EINVAL);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+
+        /* Out of the "unsigned" range, this is 1<<64 */
+        assert_se(parse_range("0-18446744073709551616", &lower, &upper) == -ERANGE);
+        assert_se(lower == 9999);
+        assert_se(upper == 9999);
+}
+
 static void test_parse_cpu_set(void) {
         cpu_set_t *c = NULL;
         int ncpus;
@@ -2378,6 +2557,7 @@ int main(int argc, char *argv[]) {
         test_u64log2();
         test_protect_errno();
         test_parse_size();
+        test_parse_range();
         test_parse_cpu_set();
         test_config_parse_iec_uint64();
         test_strextend();