util: never use ether_ntoa(), since it formats with %x, not %02x, which makes ethernet addresses look funny

src/libsystemd-network/sd-dhcp-client.c

@@ -1420,6 +1420,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd,
 }
 
 int sd_dhcp_client_start(sd_dhcp_client *client) {
+        char buffer[ETHER_ADDR_TO_STRING_MAX];
         int r;
 
         assert_return(client, -EINVAL);
@@ -1435,7 +1436,7 @@ int sd_dhcp_client_start(sd_dhcp_client *client) {
         if (r >= 0)
                 log_dhcp_client(client, "STARTED on ifindex %u with address %s",
                                 client->index,
-                                ether_ntoa(&client->client_id.mac_addr));
+                                ether_addr_to_string(&client->client_id.mac_addr, buffer));
 
         return r;
 }

src/libsystemd/sd-rtnl/test-rtnl.c

@@ -34,6 +34,7 @@
 static void test_link_configure(sd_rtnl *rtnl, int ifindex) {
         _cleanup_rtnl_message_unref_ sd_rtnl_message *message;
         const char *mac = "98:fe:94:3f:c6:18", *name = "test";
+        char buffer[ETHER_ADDR_TO_STRING_MAX];
         unsigned int mtu = 1450, mtu_out;
         const char *name_out;
         struct ether_addr mac_out;
@@ -51,7 +52,7 @@ static void test_link_configure(sd_rtnl *rtnl, int ifindex) {
         assert_se(streq(name, name_out));
 
         assert_se(sd_rtnl_message_read_ether_addr(message, IFLA_ADDRESS, &mac_out) >= 0);
-        assert_se(streq(mac, ether_ntoa(&mac_out)));
+        assert_se(streq(mac, ether_addr_to_string(&mac_out, buffer)));
 
         assert_se(sd_rtnl_message_read_u32(message, IFLA_MTU, &mtu_out) >= 0);
         assert_se(mtu == mtu_out);

src/network/networkctl.c

@@ -33,6 +33,7 @@
 #include "udev-util.h"
 #include "arphrd-list.h"
 #include "local-addresses.h"
+#include "socket-util.h"
 
 static bool arg_no_pager = false;
 static bool arg_legend = true;
@@ -402,8 +403,10 @@ static int link_status_one(sd_rtnl *rtnl, struct udev *udev, const char *name) {
         if (model)
                 printf("       Model: %s\n", model);
 
-        if (have_mac)
-                printf("  HW Address: %s\n", ether_ntoa(&e));
+        if (have_mac) {
+                char ea[ETHER_ADDR_TO_STRING_MAX];
+                printf("  HW Address: %s\n", ether_addr_to_string(&e, ea));
+        }
 
         if (mtu > 0)
                 printf("         MTU: %u\n", mtu);

src/shared/socket-util.c

@@ -727,3 +727,22 @@ bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b
 
         return false;
 }
+
+char* ether_addr_to_string(const struct ether_addr *addr, char buffer[ETHER_ADDR_TO_STRING_MAX]) {
+        assert(addr);
+        assert(buffer);
+
+        /* Like ether_ntoa() but uses %02x instead of %x to print
+         * ethernet addresses, which makes them look less funny. Also,
+         * doesn't use a static buffer. */
+
+        sprintf(buffer, "%02x:%02x:%02x:%02x:%02x:%02x",
+                addr->ether_addr_octet[0],
+                addr->ether_addr_octet[1],
+                addr->ether_addr_octet[2],
+                addr->ether_addr_octet[3],
+                addr->ether_addr_octet[4],
+                addr->ether_addr_octet[5]);
+
+        return buffer;
+}

src/shared/socket-util.h

@@ -23,6 +23,7 @@
 
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <netinet/ether.h>
 #include <sys/un.h>
 #include <asm/types.h>
 #include <linux/netlink.h>
@@ -111,3 +112,7 @@ int netlink_family_to_string_alloc(int b, char **s);
 int netlink_family_from_string(const char *s) _pure_;
 
 bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b);
+
+#define ETHER_ADDR_TO_STRING_MAX (3*6)
+
+char* ether_addr_to_string(const struct ether_addr *addr, char buffer[ETHER_ADDR_TO_STRING_MAX]);