@@ -185,3 +185,203 @@ dhcp_extract_router_msg(struct buffer *ipbuf)

     }

     return 0;

 }

+

+#if defined(_WIN32)

+

+#if defined(__GNUC__) || defined(__clang__)

+#pragma GCC diagnostic push

+#pragma GCC diagnostic ignored "-Wconversion"

+#endif

+

+/*

+ * Convert DHCP options from the command line / config file

+ * into a raw DHCP-format options string.

+ */

+

+static void

+write_dhcp_u8(struct buffer *buf, const int type, const int data, bool *error)

+{

+    if (!buf_safe(buf, 3))

+    {

+        *error = true;

+        msg(M_WARN, "write_dhcp_u8: buffer overflow building DHCP options");

+        return;

+    }

+    buf_write_u8(buf, type);

+    buf_write_u8(buf, 1);

+    buf_write_u8(buf, data);

+}

+

+static void

+write_dhcp_u32_array(struct buffer *buf, const int type, const uint32_t *data,

+                     const unsigned int len, bool *error)

+{

+    if (len > 0)

+    {

+        int i;

+        const int size = len * sizeof(uint32_t);

+

+        if (!buf_safe(buf, 2 + size))

+        {

+            *error = true;

+            msg(M_WARN, "write_dhcp_u32_array: buffer overflow building DHCP options");

+            return;

+        }

+        if (size < 1 || size > 255)

+        {

+            *error = true;

+            msg(M_WARN, "write_dhcp_u32_array: size (%d) must be > 0 and <= 255", size);

+            return;

+        }

+        buf_write_u8(buf, type);

+        buf_write_u8(buf, size);

+        for (i = 0; i < len; ++i)

+        {

+            buf_write_u32(buf, data[i]);

+        }

+    }

+}

+

+static void

+write_dhcp_str(struct buffer *buf, const int type, const char *str, bool *error)

+{

+    const int len = strlen(str);

+    if (!buf_safe(buf, 2 + len))

+    {

+        *error = true;

+        msg(M_WARN, "write_dhcp_str: buffer overflow building DHCP options");

+        return;

+    }

+    if (len < 1 || len > 255)

+    {

+        *error = true;

+        msg(M_WARN, "write_dhcp_str: string '%s' must be > 0 bytes and <= 255 bytes", str);

+        return;

+    }

+    buf_write_u8(buf, type);

+    buf_write_u8(buf, len);

+    buf_write(buf, str, len);

+}

+

+/*

+ * RFC3397 states that multiple searchdomains are encoded as follows:

+ *  - at start the length of the entire option is given

+ *  - each subdomain is preceded by its length

+ *  - each searchdomain is separated by a NUL character

+ * e.g. if you want "openvpn.net" and "duckduckgo.com" then you end up with

+ *  0x1D  0x7 openvpn 0x3 net 0x00 0x0A duckduckgo 0x3 com 0x00

+ */

+static void

+write_dhcp_search_str(struct buffer *buf, const int type, const char *const *str_array,

+                      int array_len, bool *error)

+{

+    char tmp_buf[256];

+    int i;

+    int len = 0;

+    int label_length_pos;

+

+    for (i = 0; i < array_len; i++)

+    {

+        const char *ptr = str_array[i];

+

+        if (strlen(ptr) + len + 1 > sizeof(tmp_buf))

+        {

+            *error = true;

+            msg(M_WARN, "write_dhcp_search_str: temp buffer overflow building DHCP options");

+            return;

+        }

+        /* Loop over all subdomains separated by a dot and replace the dot

+         * with the length of the subdomain */

+

+        /* label_length_pos points to the byte to be replaced by the length

+         * of the following domain label */

+        label_length_pos = len++;

+

+        while (true)

+        {

+            if (*ptr == '.' || *ptr == '\0')

+            {

+                tmp_buf[label_length_pos] = (len - label_length_pos) - 1;

+                label_length_pos = len;

+                if (*ptr == '\0')

+                {

+                    break;

+                }

+            }

+            tmp_buf[len++] = *ptr++;

+        }

+        /* And close off with an extra NUL char */

+        tmp_buf[len++] = 0;

+    }

+

+    if (!buf_safe(buf, 2 + len))

+    {

+        *error = true;

+        msg(M_WARN, "write_search_dhcp_str: buffer overflow building DHCP options");

+        return;

+    }

+    if (len > 255)

+    {

+        *error = true;

+        msg(M_WARN, "write_dhcp_search_str: search domain string must be <= 255 bytes");

+        return;

+    }

+

+    buf_write_u8(buf, type);

+    buf_write_u8(buf, len);

+    buf_write(buf, tmp_buf, len);

+}

+

+#if defined(__GNUC__) || defined(__clang__)

+#pragma GCC diagnostic pop

+#endif

+

+bool

+build_dhcp_options_string(struct buffer *buf, const struct tuntap_options *o)

+{

+    bool error = false;

+    if (o->domain)

+    {

+        write_dhcp_str(buf, 15, o->domain, &error);

+    }

+

+    if (o->netbios_scope)

+    {

+        write_dhcp_str(buf, 47, o->netbios_scope, &error);

+    }

+

+    if (o->netbios_node_type)

+    {

+        write_dhcp_u8(buf, 46, o->netbios_node_type, &error);

+    }

+

+    write_dhcp_u32_array(buf, 6, (uint32_t *)o->dns, o->dns_len, &error);

+    write_dhcp_u32_array(buf, 44, (uint32_t *)o->wins, o->wins_len, &error);

+    write_dhcp_u32_array(buf, 42, (uint32_t *)o->ntp, o->ntp_len, &error);

+    write_dhcp_u32_array(buf, 45, (uint32_t *)o->nbdd, o->nbdd_len, &error);

+

+    if (o->domain_search_list_len > 0)

+    {

+        write_dhcp_search_str(buf, 119, o->domain_search_list, o->domain_search_list_len, &error);

+    }

+

+    /* the MS DHCP server option 'Disable Netbios-over-TCP/IP

+     * is implemented as vendor option 001, value 002.

+     * A value of 001 means 'leave NBT alone' which is the default */

+    if (o->disable_nbt)

+    {

+        if (!buf_safe(buf, 8))

+        {

+            msg(M_WARN, "build_dhcp_options_string: buffer overflow building DHCP options");

+            return false;

+        }

+        buf_write_u8(buf, 43);

+        buf_write_u8(buf, 6); /* total length field */

+        buf_write_u8(buf, 0x001);

+        buf_write_u8(buf, 4); /* length of the vendor specified field */

+        buf_write_u32(buf, 0x002);

+    }

+    return !error;

+}

+

+#endif /* defined(_WIN32) */

@@ -84,4 +84,10 @@ struct dhcp_full

 in_addr_t dhcp_extract_router_msg(struct buffer *ipbuf);

+#if defined(_WIN32)

+#include "tun.h"

+

+bool build_dhcp_options_string(struct buffer *buf, const struct tuntap_options *o);

+#endif

+

 #endif /* ifndef DHCP_H */

@@ -45,6 +45,7 @@

 #include "win32.h"

 #include "wfp_block.h"

 #include "networking.h"

+#include "dhcp.h"

 #include "memdbg.h"

@@ -5554,202 +5555,6 @@ tun_standby(struct tuntap *tt)

     return ret;

 }

-#if defined(__GNUC__) || defined(__clang__)

-#pragma GCC diagnostic push

-#pragma GCC diagnostic ignored "-Wconversion"

-#endif

-

-/*

- * Convert DHCP options from the command line / config file

- * into a raw DHCP-format options string.

- */

-

-static void

-write_dhcp_u8(struct buffer *buf, const int type, const int data, bool *error)

-{

-    if (!buf_safe(buf, 3))

-    {

-        *error = true;

-        msg(M_WARN, "write_dhcp_u8: buffer overflow building DHCP options");

-        return;

-    }

-    buf_write_u8(buf, type);

-    buf_write_u8(buf, 1);

-    buf_write_u8(buf, data);

-}

-

-static void

-write_dhcp_u32_array(struct buffer *buf, const int type, const uint32_t *data,

-                     const unsigned int len, bool *error)

-{

-    if (len > 0)

-    {

-        int i;

-        const int size = len * sizeof(uint32_t);

-

-        if (!buf_safe(buf, 2 + size))

-        {

-            *error = true;

-            msg(M_WARN, "write_dhcp_u32_array: buffer overflow building DHCP options");

-            return;

-        }

-        if (size < 1 || size > 255)

-        {

-            *error = true;

-            msg(M_WARN, "write_dhcp_u32_array: size (%d) must be > 0 and <= 255", size);

-            return;

-        }

-        buf_write_u8(buf, type);

-        buf_write_u8(buf, size);

-        for (i = 0; i < len; ++i)

-        {

-            buf_write_u32(buf, data[i]);

-        }

-    }

-}

-

-static void

-write_dhcp_str(struct buffer *buf, const int type, const char *str, bool *error)

-{

-    const int len = strlen(str);

-    if (!buf_safe(buf, 2 + len))

-    {

-        *error = true;

-        msg(M_WARN, "write_dhcp_str: buffer overflow building DHCP options");

-        return;

-    }

-    if (len < 1 || len > 255)

-    {

-        *error = true;

-        msg(M_WARN, "write_dhcp_str: string '%s' must be > 0 bytes and <= 255 bytes", str);

-        return;

-    }

-    buf_write_u8(buf, type);

-    buf_write_u8(buf, len);

-    buf_write(buf, str, len);

-}

-

-/*

- * RFC3397 states that multiple searchdomains are encoded as follows:

- *  - at start the length of the entire option is given

- *  - each subdomain is preceded by its length

- *  - each searchdomain is separated by a NUL character

- * e.g. if you want "openvpn.net" and "duckduckgo.com" then you end up with

- *  0x1D  0x7 openvpn 0x3 net 0x00 0x0A duckduckgo 0x3 com 0x00

- */

-static void

-write_dhcp_search_str(struct buffer *buf, const int type, const char *const *str_array,

-                      int array_len, bool *error)

-{

-    char tmp_buf[256];

-    int i;

-    int len = 0;

-    int label_length_pos;

-

-    for (i = 0; i < array_len; i++)

-    {

-        const char *ptr = str_array[i];

-

-        if (strlen(ptr) + len + 1 > sizeof(tmp_buf))

-        {

-            *error = true;

-            msg(M_WARN, "write_dhcp_search_str: temp buffer overflow building DHCP options");

-            return;

-        }

-        /* Loop over all subdomains separated by a dot and replace the dot

-         * with the length of the subdomain */

-

-        /* label_length_pos points to the byte to be replaced by the length

-         * of the following domain label */

-        label_length_pos = len++;

-

-        while (true)

-        {

-            if (*ptr == '.' || *ptr == '\0')

-            {

-                tmp_buf[label_length_pos] = (len - label_length_pos) - 1;

-                label_length_pos = len;

-                if (*ptr == '\0')

-                {

-                    break;

-                }

-            }

-            tmp_buf[len++] = *ptr++;

-        }

-        /* And close off with an extra NUL char */

-        tmp_buf[len++] = 0;

-    }

-

-    if (!buf_safe(buf, 2 + len))

-    {

-        *error = true;

-        msg(M_WARN, "write_search_dhcp_str: buffer overflow building DHCP options");

-        return;

-    }

-    if (len > 255)

-    {

-        *error = true;

-        msg(M_WARN, "write_dhcp_search_str: search domain string must be <= 255 bytes");

-        return;

-    }

-

-    buf_write_u8(buf, type);

-    buf_write_u8(buf, len);

-    buf_write(buf, tmp_buf, len);

-}

-

-#if defined(__GNUC__) || defined(__clang__)

-#pragma GCC diagnostic pop

-#endif

-

-static bool

-build_dhcp_options_string(struct buffer *buf, const struct tuntap_options *o)

-{

-    bool error = false;

-    if (o->domain)

-    {

-        write_dhcp_str(buf, 15, o->domain, &error);

-    }

-

-    if (o->netbios_scope)

-    {

-        write_dhcp_str(buf, 47, o->netbios_scope, &error);

-    }

-

-    if (o->netbios_node_type)

-    {

-        write_dhcp_u8(buf, 46, o->netbios_node_type, &error);

-    }

-

-    write_dhcp_u32_array(buf, 6, (uint32_t *)o->dns, o->dns_len, &error);

-    write_dhcp_u32_array(buf, 44, (uint32_t *)o->wins, o->wins_len, &error);

-    write_dhcp_u32_array(buf, 42, (uint32_t *)o->ntp, o->ntp_len, &error);

-    write_dhcp_u32_array(buf, 45, (uint32_t *)o->nbdd, o->nbdd_len, &error);

-

-    if (o->domain_search_list_len > 0)

-    {

-        write_dhcp_search_str(buf, 119, o->domain_search_list, o->domain_search_list_len, &error);

-    }

-

-    /* the MS DHCP server option 'Disable Netbios-over-TCP/IP

-     * is implemented as vendor option 001, value 002.

-     * A value of 001 means 'leave NBT alone' which is the default */

-    if (o->disable_nbt)

-    {

-        if (!buf_safe(buf, 8))

-        {

-            msg(M_WARN, "build_dhcp_options_string: buffer overflow building DHCP options");

-            return false;

-        }

-        buf_write_u8(buf, 43);

-        buf_write_u8(buf, 6); /* total length field */

-        buf_write_u8(buf, 0x001);

-        buf_write_u8(buf, 4); /* length of the vendor specified field */

-        buf_write_u32(buf, 0x002);

-    }

-    return !error;

-}

-

 static void

 fork_dhcp_action(struct tuntap *tt)

 {