tunneling: Simplify path MTU discovery logic.

[openvswitch] / lib / util.c

diff --git a/lib/util.c b/lib/util.c
index 12403cbbcf4d35e132cbe48ac40255380a97c2d1..193efb9237c26fee14f85ee20ba0f08af3e6ef31 100644 (file)
--- a/lib/util.c
+++ b/lib/util.c
@@ -27,6 +27,8 @@
 
 VLOG_DEFINE_THIS_MODULE(util);
 
+COVERAGE_DEFINE(util_xalloc);
+
 const char *program_name;
 
 void
@@ -156,8 +158,7 @@ ovs_fatal(int err_no, const char *format, ...)
     vfprintf(stderr, format, args);
     va_end(args);
     if (err_no != 0)
-        fprintf(stderr, " (%s)",
-                err_no == EOF ? "end of file" : strerror(err_no));
+        fprintf(stderr, " (%s)", ovs_retval_to_string(err_no));
     putc('\n', stderr);
 
     exit(EXIT_FAILURE);
@@ -174,14 +175,40 @@ ovs_error(int err_no, const char *format, ...)
     vfprintf(stderr, format, args);
     va_end(args);
     if (err_no != 0) {
-        fprintf(stderr, " (%s)",
-                err_no == EOF ? "end of file" : strerror(err_no));
+        fprintf(stderr, " (%s)", ovs_retval_to_string(err_no));
     }
     putc('\n', stderr);
 
     errno = save_errno;
 }
 
+/* Many OVS functions return an int which is one of:
+ * - 0: no error yet
+ * - >0: errno value
+ * - EOF: end of file (not necessarily an error; depends on the function called)
+ *
+ * Returns the appropriate human-readable string. The caller must copy the
+ * string if it wants to hold onto it, as the storage may be overwritten on
+ * subsequent function calls.
+ */
+const char *
+ovs_retval_to_string(int retval)
+{
+    static char unknown[48];
+
+    if (!retval) {
+        return "";
+    }
+    if (retval > 0) {
+        return strerror(retval);
+    }
+    if (retval == EOF) {
+        return "End of file";
+    }
+    snprintf(unknown, sizeof unknown, "***unknown return value: %d***", retval);
+    return unknown;
+}
+
 /* Sets program_name based on 'argv0'.  Should be called at the beginning of
  * main(), as "set_program_name(argv[0]);".  */
 void set_program_name(const char *argv0)
@@ -364,6 +391,33 @@ hexit_value(int c)
     }
 }
 
+/* Returns the integer value of the 'n' hexadecimal digits starting at 's', or
+ * UINT_MAX if one of those "digits" is not really a hex digit.  If 'ok' is
+ * nonnull, '*ok' is set to true if the conversion succeeds or to false if a
+ * non-hex digit is detected. */
+unsigned int
+hexits_value(const char *s, size_t n, bool *ok)
+{
+    unsigned int value;
+    size_t i;
+
+    value = 0;
+    for (i = 0; i < n; i++) {
+        int hexit = hexit_value(s[i]);
+        if (hexit < 0) {
+            if (ok) {
+                *ok = false;
+            }
+            return UINT_MAX;
+        }
+        value = (value << 4) + hexit;
+    }
+    if (ok) {
+        *ok = true;
+    }
+    return value;
+}
+
 /* Returns the current working directory as a malloc()'d string, or a null
  * pointer if the current working directory cannot be determined. */
 char *