udhcp: optional support for non-standard DHCP ports (+300 bytes when selected)

1 files changed, 17 insertions, 0 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index f54bc08f1..7fca184ab 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -133,6 +133,7 @@ int udhcpc_main(int argc, char **argv)
 {
         uint8_t *temp, *message;
         char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_A, *str_t;
+        USE_FEATURE_UDHCP_PORT(char *str_P;)
         llist_t *list_O = NULL;
 #if ENABLE_FEATURE_UDHCPC_ARPING
         char *str_W;
@@ -181,6 +182,7 @@ int udhcpc_main(int argc, char **argv)
                 OPT_a = 1 << 20,
                 OPT_W = 1 << 21,
 #endif
+                OPT_P = 1 << 22,
         };
 #if ENABLE_GETOPT_LONG
         static const char udhcpc_longopts[] ALIGN1 =
@@ -207,9 +209,16 @@ int udhcpc_main(int argc, char **argv)
                 "arping\0"         No_argument       "a"
 #endif
                 "request-option\0" Required_argument "O"
+#if ENABLE_FEATURE_UDHCP_PORT
+                "client-port\0"    Required_argument "P"
+#endif
                 ;
 #endif
         /* Default options. */
+#if ENABLE_FEATURE_UDHCP_PORT
+        SERVER_PORT = 67;
+        CLIENT_PORT = 68;
+#endif
         client_config.interface = "eth0";
         client_config.script = DEFAULT_SCRIPT;
 
@@ -220,11 +229,13 @@ int udhcpc_main(int argc, char **argv)
 #endif
         opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:"
                 USE_FEATURE_UDHCPC_ARPING("aW:")
+                USE_FEATURE_UDHCP_PORT("P:")
                 "O:"
                 , &str_c, &str_V, &str_h, &str_h, &str_F
                 , &client_config.interface, &client_config.pidfile, &str_r
                 , &client_config.script, &str_T, &str_t, &str_A
                 USE_FEATURE_UDHCPC_ARPING(, &str_W)
+                USE_FEATURE_UDHCP_PORT(, &str_P)
                 , &list_O
                 );
 
@@ -276,6 +287,12 @@ int udhcpc_main(int argc, char **argv)
                 openlog(applet_name, LOG_PID, LOG_LOCAL0);
                 logmode |= LOGMODE_SYSLOG;
         }
+#if ENABLE_FEATURE_UDHCP_PORT
+        if (opt & OPT_P) {
+                CLIENT_PORT = xatou16(str_P);
+                SERVER_PORT = CLIENT_PORT - 1;
+        }
+#endif
         while (list_O) {
                 int n = index_in_strings(dhcp_option_strings, list_O->data);
                 if (n < 0)