allow suppression of default client-id. fixes bug 000037. allows

busybox to match kernel and u-boot behavior with respect to client-id.

3 files changed, 17 insertions, 6 deletions

diff --git a/include/usage.h b/include/usage.h
index 363b01cdd..21980eeba 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2931,9 +2931,10 @@
         "Adjust filesystem options on ext[23] filesystems.\n\n"
 
 #define udhcpc_trivial_usage \
-        "[-fbnqv] [-c CLIENTID] [-H HOSTNAME] [-i INTERFACE]\n[-p pidfile] [-r IP] [-s script]"
+        "[-Cfbnqv] [-c CLIENTID] [-H HOSTNAME] [-i INTERFACE]\n[-p pidfile] [-r IP] [-s script]"
 #define udhcpc_full_usage \
-        "\t-c,\t--clientid=CLIENTID\tClient identifier\n" \
+        "\t-c,\t--clientid=CLIENTID\tSet client identifier\n" \
+        "\t-C,\t--clientid-none\tSuppress default client identifier\n" \
         "\t-H,\t--hostname=HOSTNAME\tClient hostname\n" \
         "\t-h,\t                   \tAlias for -H\n" \
         "\t-f,\t--foreground\tDo not fork after getting lease\n" \
diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c
index c5e1c210b..2695b06ed 100644
--- a/networking/udhcp/clientpacket.c
+++ b/networking/udhcp/clientpacket.c
@@ -76,7 +76,8 @@ static void init_packet(struct dhcpMessage *packet, char type)
 
         init_header(packet, type);
         memcpy(packet->chaddr, client_config.arp, 6);
-        add_option_string(packet->options, client_config.clientid);
+        if (client_config.clientid)
+            add_option_string(packet->options, client_config.clientid);
         if (client_config.hostname) add_option_string(packet->options, client_config.hostname);
         if (client_config.fqdn) add_option_string(packet->options, client_config.fqdn);
         add_option_string(packet->options, (uint8_t *) &vendor_id);
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index eeaf5531d..35ae757e7 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -77,7 +77,8 @@ static void __attribute__ ((noreturn)) show_usage(void)
 {
         printf(
 "Usage: udhcpc [OPTIONS]\n\n"
-"  -c, --clientid=CLIENTID         Client identifier\n"
+"  -c, --clientid=CLIENTID         Set client identifier\n"
+"  -C, --clientid-none             Suppress default client identifier\n"
 "  -H, --hostname=HOSTNAME         Client hostname\n"
 "  -h                              Alias for -H\n"
 "  -F, --fqdn=FQDN                 Client fully qualified domain name\n"
@@ -193,9 +194,11 @@ int main(int argc, char *argv[])
         long now;
         int max_fd;
         int sig;
+        int no_clientid = 0;
 
         static const struct option arg_options[] = {
                 {"clientid",    required_argument,      0, 'c'},
+                {"clientid-none", no_argument,          0, 'C'},
                 {"foreground",  no_argument,            0, 'f'},
                 {"background",  no_argument,            0, 'b'},
                 {"hostname",    required_argument,      0, 'H'},
@@ -214,11 +217,12 @@ int main(int argc, char *argv[])
         /* get options */
         while (1) {
                 int option_index = 0;
-                c = getopt_long(argc, argv, "c:fbH:h:F:i:np:qr:s:v", arg_options, &option_index);
+                c = getopt_long(argc, argv, "c:CfbH:h:F:i:np:qr:s:v", arg_options, &option_index);
                 if (c == -1) break;
 
                 switch (c) {
                 case 'c':
+                        if (no_clientid) show_usage();
                         len = strlen(optarg) > 255 ? 255 : strlen(optarg);
                         if (client_config.clientid) free(client_config.clientid);
                         client_config.clientid = xmalloc(len + 2);
@@ -227,6 +231,10 @@ int main(int argc, char *argv[])
                         client_config.clientid[OPT_DATA] = '\0';
                         strncpy(client_config.clientid + OPT_DATA, optarg, len);
                         break;
+                case 'C':
+                        if (client_config.clientid) show_usage();
+                        no_clientid = 1;
+                        break;
                 case 'f':
                         client_config.foreground = 1;
                         break;
@@ -293,7 +301,8 @@ int main(int argc, char *argv[])
                            NULL, client_config.arp) < 0)
                 return 1;
 
-        if (!client_config.clientid) {
+        /* if not set, and not suppressed, setup the default client ID */
+        if (!client_config.clientid && !no_clientid) {
                 client_config.clientid = xmalloc(6 + 3);
                 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
                 client_config.clientid[OPT_LEN] = 7;