udhcpc: add -o "do not request options by default" switch

(by L. Gabriel Somlo <somlo AT cmu.edu>)

function                                             old     new   delta
udhcpc_main                                         2513    2554     +41
static.udhcpc_longopts                               226     247     +21
add_param_req_option                                 119     132     +13
packed_usage                                       23952   23964     +12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 87/0)               Total: 87 bytes

1 files changed, 5 insertions, 1 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index bc0676152..fb328cb03 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -182,6 +182,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 OPT_W = 1 << 21,
 #endif
                 OPT_P = 1 << 22,
+                OPT_o = 1 << 23,
         };
 #if ENABLE_GETOPT_LONG
         static const char udhcpc_longopts[] ALIGN1 =
@@ -211,6 +212,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #if ENABLE_FEATURE_UDHCP_PORT
                 "client-port\0"    Required_argument "P"
 #endif
+                "no-default-options\0" No_argument   "o"
                 ;
 #endif
         /* Default options. */
@@ -230,7 +232,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
         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:"
+                "O:o"
                 , &str_c, &str_V, &str_h, &str_h, &str_F
                 , &client_config.interface, &client_config.pidfile, &str_r
                 , &client_config.script
@@ -291,6 +293,8 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 SERVER_PORT = CLIENT_PORT - 1;
         }
 #endif
+        if (opt & OPT_o)
+                client_config.no_default_options = 1;
         while (list_O) {
                 int n = index_in_strings(dhcp_option_strings, list_O->data);
                 if (n < 0)