udhcpc: make -O <numeric_opt> work. Closes 5402

function                                             old     new   delta
udhcpc_main                                         2642    2685     +43
udhcp_recv_raw_packet                                414     415      +1
d6_recv_raw_packet                                   248     249      +1
udhcpc6_main                                        2430    2413     -17
add_client_options                                   239     213     -26
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/2 up/down: 45/-43)              Total: 2 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 21 insertions, 13 deletions

diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index d9d8b9b56..dda4a9112 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -965,8 +965,6 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
                 SERVER_PORT = CLIENT_PORT - 1;
         }
 #endif
-        if (opt & OPT_o)
-                client_config.no_default_options = 1;
         while (list_O) {
                 char *optstr = llist_pop(&list_O);
                 unsigned n = bb_strtou(optstr, NULL, 0);
@@ -976,6 +974,16 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
                 }
                 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
         }
+        if (!(opt & OPT_o)) {
+                /*
+                unsigned i, n;
+                for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
+                        if (dhcp_optflags[i].flags & OPTION_REQ) {
+                                client_config.opt_mask[n >> 3] |= 1 << (n & 7);
+                        }
+                }
+                */
+        }
         while (list_x) {
                 char *optstr = llist_pop(&list_x);
                 char *colon = strchr(optstr, ':');
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 4e7bd4bbc..bc1db7087 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -589,7 +589,6 @@ static void init_packet(struct dhcp_packet *packet, char type)
 
 static void add_client_options(struct dhcp_packet *packet)
 {
-        uint8_t c;
         int i, end, len;
 
         udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE));
@@ -599,13 +598,9 @@ static void add_client_options(struct dhcp_packet *packet)
          * No bounds checking because it goes towards the head of the packet. */
         end = udhcp_end_option(packet->options);
         len = 0;
-        for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) {
-                if ((   (dhcp_optflags[i].flags & OPTION_REQ)
-                     && !client_config.no_default_options
-                    )
-                 || (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
-                ) {
-                        packet->options[end + OPT_DATA + len] = c;
+        for (i = 1; i < DHCP_END; i++) {
+                if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
+                        packet->options[end + OPT_DATA + len] = i;
                         len++;
                 }
         }
@@ -1257,8 +1252,6 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 SERVER_PORT = CLIENT_PORT - 1;
         }
 #endif
-        if (opt & OPT_o)
-                client_config.no_default_options = 1;
         while (list_O) {
                 char *optstr = llist_pop(&list_O);
                 unsigned n = bb_strtou(optstr, NULL, 0);
@@ -1268,6 +1261,14 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 }
                 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
         }
+        if (!(opt & OPT_o)) {
+                unsigned i, n;
+                for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
+                        if (dhcp_optflags[i].flags & OPTION_REQ) {
+                                client_config.opt_mask[n >> 3] |= 1 << (n & 7);
+                        }
+                }
+        }
         while (list_x) {
                 char *optstr = llist_pop(&list_x);
                 char *colon = strchr(optstr, ':');
diff --git a/networking/udhcp/dhcpc.h b/networking/udhcp/dhcpc.h
index 2b3599120..2859a0772 100644
--- a/networking/udhcp/dhcpc.h
+++ b/networking/udhcp/dhcpc.h
@@ -9,7 +9,6 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
 struct client_config_t {
         uint8_t client_mac[6];          /* Our mac address */
-        char no_default_options;        /* Do not include default options in request */
         IF_FEATURE_UDHCP_PORT(uint16_t port;)
         int ifindex;                    /* Index number of the interface to use */
         uint8_t opt_mask[256 / 8];      /* Bitmask of options to send (-O option) */