From eaa71334348aa0d99abf5588e17b3e55d0db28ce Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Wed, 15 Jul 2009 10:58:30 -0700
Subject: [PATCH] Add macros for parsing MAC addresses from strings.

---
 lib/cfg.c             |  4 ++--
 lib/packets.h         | 23 +++++++++++++++++++++++
 utilities/ovs-ofctl.c |  4 ++--
 vswitchd/bridge.c     |  4 ++--
 4 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/lib/cfg.c b/lib/cfg.c
index 901315ed9..a53e6e380 100644
--- a/lib/cfg.c
+++ b/lib/cfg.c
@@ -1101,8 +1101,8 @@ find_key(const char *key)
 static bool
 parse_mac(const char *s, uint8_t mac[6])
 {
-    return sscanf(s, "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8,
-                  &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]) == 6;
+    return (sscanf(s, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
+            == ETH_ADDR_SCAN_COUNT);
 }
 
 static bool
diff --git a/lib/packets.h b/lib/packets.h
index 8ccc73404..d12cc0403 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -98,11 +98,34 @@ static inline bool eth_addr_is_reserved(const uint8_t ea[ETH_ADDR_LEN])
             && (ea[5] & 0xf0) == 0x00);
 }
 
+/* Example:
+ *
+ * uint8_t mac[ETH_ADDR_LEN];
+ *    [...]
+ * printf("The Ethernet address is "ETH_ADDR_FMT"\n", ETH_ADDR_ARGS(mac));
+ *
+ */
 #define ETH_ADDR_FMT                                                    \
     "%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8":%02"PRIx8
 #define ETH_ADDR_ARGS(ea)                                   \
     (ea)[0], (ea)[1], (ea)[2], (ea)[3], (ea)[4], (ea)[5]
 
+/* Example:
+ *
+ * char *string = "1 00:11:22:33:44:55 2";
+ * uint8_t mac[ETH_ADDR_LEN];
+ * int a, b;
+ *
+ * if (sscanf(string, "%d"ETH_ADDR_SCAN_FMT"%d",
+ *     &a, ETH_ADDR_SCAN_ARGS(mac), &b) == 1 + ETH_ADDR_SCAN_COUNT + 1) {
+ *     ...
+ * }
+ */
+#define ETH_ADDR_SCAN_FMT "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8
+#define ETH_ADDR_SCAN_ARGS(ea) \
+        &(ea)[0], &(ea)[1], &(ea)[2], &(ea)[3], &(ea)[4], &(ea)[5]
+#define ETH_ADDR_SCAN_COUNT 6
+
 #define ETH_TYPE_IP            0x0800
 #define ETH_TYPE_ARP           0x0806
 #define ETH_TYPE_VLAN          0x8100
diff --git a/utilities/ovs-ofctl.c b/utilities/ovs-ofctl.c
index 583e5548b..04a869a2f 100644
--- a/utilities/ovs-ofctl.c
+++ b/utilities/ovs-ofctl.c
@@ -442,8 +442,8 @@ str_to_u32(const char *str)
 static void
 str_to_mac(const char *str, uint8_t mac[6]) 
 {
-    if (sscanf(str, "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8,
-               &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]) != 6) {
+    if (sscanf(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
+        != ETH_ADDR_SCAN_COUNT) {
         ovs_fatal(0, "invalid mac address %s", str);
     }
 }
diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 224a3e5f7..5d8a5b067 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -2437,8 +2437,8 @@ bond_unixctl_migrate(struct unixctl_conn *conn, const char *args_)
         return;
     }
 
-    if (sscanf(hash_s, "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8,
-               &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]) == 6) {
+    if (sscanf(hash_s, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
+        == ETH_ADDR_SCAN_COUNT) {
         hash = bond_hash(mac);
     } else if (strspn(hash_s, "0123456789") == strlen(hash_s)) {
         hash = atoi(hash_s) & BOND_MASK;
-- 
2.43.0