Encapsulate all string option additions into options.c. Note that these

functions already existed, but were in dhcp.c -- this is just code motion
between compilation units.

ndhc/dhcp.c

@@ -146,7 +146,7 @@ static int send_dhcp_cooked(struct client_state_t *cs, struct dhcpmsg *payload)
 
     ssize_t endloc = get_end_option_idx(payload);
     if (endloc < 0) {
-        log_error("send_dhcp_cooked: Attempt to send packet with no DCODE_END.");
+        log_error("send_dhcp_cooked: No end marker.  Not sending.");
         goto out_fd;
     }
     size_t payload_len =
@@ -407,7 +407,7 @@ static int send_dhcp_raw(struct dhcpmsg *payload)
     // and drop packets that are longer than 562 bytes.
     ssize_t endloc = get_end_option_idx(payload);
     if (endloc < 0) {
-        log_error("send_dhcp_raw: Attempt to send packet with no DCODE_END.");
+        log_error("send_dhcp_raw: No end marker.  Not sending.");
         close(fd);
         return ret;
     }
@@ -538,41 +538,6 @@ void handle_packet(struct client_state_t *cs)
     packet_action(cs, &packet, msgtype);
 }
 
-static void add_option_vendor(struct dhcpmsg *packet)
-{
-    size_t len = strlen(client_config.vendor);
-    if (len)
-        add_option_string(packet, DCODE_VENDOR, client_config.vendor, len);
-    else
-        add_option_string(packet, DCODE_VENDOR, "ndhc", sizeof "ndhc" - 1);
-}
-
-static void add_option_clientid(struct dhcpmsg *packet)
-{
-    char buf[sizeof client_config.clientid + 1];
-    size_t len = 6;
-    buf[0] = 1; // Ethernet MAC
-    if (!client_config.clientid_mac) {
-        size_t slen = strlen(client_config.clientid);
-        if (!slen) {
-            memcpy(buf+1, client_config.arp, len);
-        } else {
-            buf[0] = 0; // Not a hardware address
-            len = slen;
-            memcpy(buf+1, client_config.clientid, slen);
-        }
-    } else
-        memcpy(buf+1, client_config.clientid, len);
-    add_option_string(packet, DCODE_CLIENT_ID, buf, len+1);
-}
-
-static void add_option_hostname(struct dhcpmsg *packet)
-{
-    size_t len = strlen(client_config.hostname);
-    if (len)
-        add_option_string(packet, DCODE_HOSTNAME, client_config.hostname, len);
-}
-
 // Initialize a DHCP client packet that will be sent to a server
 static struct dhcpmsg init_packet(char type, uint32_t xid)
 {

ndhc/options.c

@@ -217,8 +217,8 @@ ssize_t get_end_option_idx(struct dhcpmsg *packet)
 
 // add an option string to the options (an option string contains an option
 // code, length, then data)
-size_t add_option_string(struct dhcpmsg *packet, uint8_t code, char *str,
+static size_t add_option_string(struct dhcpmsg *packet, uint8_t code,
-                         size_t slen)
+                                char *str, size_t slen)
 {
     size_t len = sizeof_option(code, slen);
     if (slen > 255 || len != slen + 2) {
@@ -337,3 +337,38 @@ void add_option_serverid(struct dhcpmsg *packet, uint32_t sid)
     add_u32_option(packet, DCODE_SERVER_ID, sid);
 }
 
+void add_option_vendor(struct dhcpmsg *packet)
+{
+    size_t len = strlen(client_config.vendor);
+    if (len)
+        add_option_string(packet, DCODE_VENDOR, client_config.vendor, len);
+    else
+        add_option_string(packet, DCODE_VENDOR, "ndhc", sizeof "ndhc" - 1);
+}
+
+void add_option_clientid(struct dhcpmsg *packet)
+{
+    char buf[sizeof client_config.clientid + 1];
+    size_t len = 6;
+    buf[0] = 1; // Ethernet MAC
+    if (!client_config.clientid_mac) {
+        size_t slen = strlen(client_config.clientid);
+        if (!slen) {
+            memcpy(buf+1, client_config.arp, len);
+        } else {
+            buf[0] = 0; // Not a hardware address
+            len = slen;
+            memcpy(buf+1, client_config.clientid, slen);
+        }
+    } else
+        memcpy(buf+1, client_config.clientid, len);
+    add_option_string(packet, DCODE_CLIENT_ID, buf, len+1);
+}
+
+void add_option_hostname(struct dhcpmsg *packet)
+{
+    size_t len = strlen(client_config.hostname);
+    if (len)
+        add_option_string(packet, DCODE_HOSTNAME, client_config.hostname, len);
+}
+

ndhc/options.h

@@ -72,12 +72,14 @@ int option_valid_list(uint8_t code);
 
 uint8_t *get_option_data(struct dhcpmsg *packet, int code, ssize_t *optlen);
 ssize_t get_end_option_idx(struct dhcpmsg *packet);
-size_t add_option_string(struct dhcpmsg *packet, uint8_t code, char *str,
-                         size_t slen);
 size_t add_option_request_list(struct dhcpmsg *packet);
+
 void add_option_msgtype(struct dhcpmsg *packet, uint8_t type);
 void add_option_reqip(struct dhcpmsg *packet, uint32_t ip);
 void add_option_maxsize(struct dhcpmsg *packet);
 void add_option_serverid(struct dhcpmsg *packet, uint32_t sid);
+void add_option_vendor(struct dhcpmsg *packet);
+void add_option_clientid(struct dhcpmsg *packet);
+void add_option_hostname(struct dhcpmsg *packet);
 
 #endif