util: Library routines for printing and scanning large hex integers.

Geneve options are variable length and up to 124 bytes long, which means
that they can't be easily manipulated by the integer string functions
like we do for other fields. This adds a few helper routines to make
these operations easier.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/dynamic-string.c b/lib/dynamic-string.c
index 914af64c1..a6c8f6c76 100644
--- a/lib/dynamic-string.c
+++ b/lib/dynamic-string.c
@@ -361,6 +361,29 @@ ds_swap(struct ds *a, struct ds *b)
     *b = temp;
 }
 
+void
+ds_put_hex(struct ds *ds, const void *buf_, size_t size)
+{
+    const uint8_t *buf = buf_;
+    bool printed = false;
+    int i;
+
+    for (i = 0; i < size; i++) {
+        uint8_t val = buf[i];
+        if (val || printed) {
+            if (!printed) {
+                ds_put_format(ds, "0x%"PRIx8, val);
+            } else {
+                ds_put_format(ds, "%02"PRIx8, val);
+            }
+            printed = true;
+        }
+    }
+    if (!printed) {
+        ds_put_char(ds, '0');
+    }
+}
+
 /* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
  * line.  Numeric offsets are also included, starting at 'ofs' for the first
  * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters