set_lladdr: use networking API net_addr_ll_set() on Linux

Make sure that set_addr() uses the proper networking backend when
setting the LL address of a TAP interface.

This operation was overlooked while implementing the networking APIs on
the Linux platform.

Reported-by: Jan Hugo Prins <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
Tested-by: Jan Hugo Prins <[email protected]>
Acked-by: Gert Doering <[email protected]>
Message-Id: <[email protected]>
URL: https://www.mail-archive.com/[email protected]/msg22791.html
Signed-off-by: Gert Doering <[email protected]>

Author: ordex

src/openvpn/init.c

@@ -1176,7 +1176,7 @@ do_persist_tuntap(const struct options *options, openvpn_net_ctx_t *ctx)
                ctx);
         if (options->persist_mode && options->lladdr)
         {
-            set_lladdr(options->dev, options->lladdr, NULL);
+            set_lladdr(ctx, options->dev, options->lladdr, NULL);
         }
         return true;
 #else  /* ifdef ENABLE_FEATURE_TUN_PERSIST */
@@ -1853,7 +1853,8 @@ do_open_tun(struct context *c)
     /* set the hardware address */
     if (c->options.lladdr)
     {
-        set_lladdr(c->c1.tuntap->actual_name, c->options.lladdr, c->c2.es);
+        set_lladdr(&c->net_ctx, c->c1.tuntap->actual_name, c->options.lladdr,
+                   c->c2.es);
     }
 
     /* do ifconfig */

src/openvpn/lladdr.c

@@ -15,10 +15,9 @@
 #include "lladdr.h"
 
 int
-set_lladdr(const char *ifname, const char *lladdr,
+set_lladdr(openvpn_net_ctx_t *ctx, const char *ifname, const char *lladdr,
            const struct env_set *es)
 {
-    struct argv argv = argv_new();
     int r;
 
     if (!ifname || !lladdr)
@@ -27,17 +26,13 @@ set_lladdr(const char *ifname, const char *lladdr,
     }
 
 #if defined(TARGET_LINUX)
-#ifdef ENABLE_IPROUTE
-    argv_printf(&argv,
-                "%s link set addr %s dev %s",
-                iproute_path, lladdr, ifname);
-#else
-    argv_printf(&argv,
-                "%s %s hw ether %s",
-                IFCONFIG_PATH,
-                ifname, lladdr);
-#endif
-#elif defined(TARGET_SOLARIS)
+    uint8_t addr[ETH_ALEN];
+
+    sscanf(lladdr, MAC_FMT, MAC_SCAN_ARG(addr));
+    r = (net_addr_ll_set(ctx, ifname, addr) == 0);
+#else /* if defined(TARGET_LINUX) */
+    struct argv argv = argv_new();
+#if defined(TARGET_SOLARIS)
     argv_printf(&argv,
                 "%s %s ether %s",
                 IFCONFIG_PATH,
@@ -57,18 +52,19 @@ set_lladdr(const char *ifname, const char *lladdr,
                 "%s %s ether %s",
                 IFCONFIG_PATH,
                 ifname, lladdr);
-#else  /* if defined(TARGET_LINUX) */
+#else  /* if defined(TARGET_SOLARIS) */
     msg(M_WARN, "Sorry, but I don't know how to configure link layer addresses on this operating system.");
     return -1;
-#endif /* if defined(TARGET_LINUX) */
-
+#endif /* if defined(TARGET_SOLARIS) */
     argv_msg(M_INFO, &argv);
     r = openvpn_execve_check(&argv, es, M_WARN, "ERROR: Unable to set link layer address.");
+    argv_free(&argv);
+#endif /* if defined(TARGET_LINUX) */
+
     if (r)
     {
         msg(M_INFO, "TUN/TAP link layer address set to %s", lladdr);
     }
 
-    argv_free(&argv);
     return r;
 }

src/openvpn/lladdr.h

@@ -3,6 +3,7 @@
  */
 
 #include "misc.h"
+#include "networking.h"
 
-int set_lladdr(const char *ifname, const char *lladdr,
+int set_lladdr(openvpn_net_ctx_t *ctx, const char *ifname, const char *lladdr,
                const struct env_set *es);