Add DNS support

[u-boot] / common / cmd_net.c

diff --git a/common/cmd_net.c b/common/cmd_net.c
index 68183c49af9233666705f2025fad4ec0ccebb84b..ac706ae8d5e73eb7f6f58d173b3c1e83eba6935f 100644 (file)
--- a/common/cmd_net.c
+++ b/common/cmd_net.c
@@ -353,3 +353,52 @@ U_BOOT_CMD(
        "[NTP server IP]\n"
 );
 #endif
+
+#if defined(CONFIG_CMD_DNS)
+int do_dns(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+       if (argc == 1) {
+               cmd_usage(cmdtp);
+               return -1;
+       }
+
+       /*
+        * We should check for a valid hostname:
+        * - Each label must be between 1 and 63 characters long
+        * - the entire hostname has a maximum of 255 characters
+        * - only the ASCII letters 'a' through 'z' (case-insensitive),
+        *   the digits '0' through '9', and the hyphen
+        * - cannot begin or end with a hyphen
+        * - no other symbols, punctuation characters, or blank spaces are
+        *   permitted
+        * but hey - this is a minimalist implmentation, so only check length
+        * and let the name server deal with things.
+        */
+       if (strlen(argv[1]) >= 255) {
+               printf("dns error: hostname too long\n");
+               return 1;
+       }
+
+       NetDNSResolve = argv[1];
+
+       if (argc == 3)
+               NetDNSenvvar = argv[2];
+       else
+               NetDNSenvvar = NULL;
+
+       if (NetLoop(DNS) < 0) {
+               printf("dns lookup of %s failed, check setup\n", argv[1]);
+               return 1;
+       }
+
+       return 0;
+}
+
+U_BOOT_CMD(
+       dns,    3,      1,      do_dns,
+       "lookup the IP of a hostname",
+       "hostname [envvar]"
+);
+
+#endif /* CONFIG_CMD_DNS */
+