diff --git a/src/buffer.h b/src/buffer.h
new file mode 100644
index 0000000..6e953f1
--- /dev/null
+++ b/src/buffer.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include "common.h"
+
+typedef struct buffer buffer_t;
+
+struct buffer {
+    uint8_t *data;
+    uint8_t *read;
+    uint8_t *write;
+    uint8_t *end;
+};
+
+static inline void buffer_setup (buffer_t *buffer, void *data, size_t size)
+{
+    if (!data)
+        data = malloc(ALIGN(size));
+
+    buffer->data  = data;
+    buffer->read  = data;
+    buffer->write = data;
+    buffer->end   = data;
+    buffer->end  += size;
+}
+
+static inline void buffer_format (buffer_t *buffer)
+{
+    buffer->write = buffer->data;
+    buffer->read  = buffer->data;
+}
+
+_pure_
+static inline size_t buffer_size (buffer_t *buffer)
+{
+    return buffer->end-buffer->data;
+}
+
+_pure_
+static inline size_t buffer_write_size (buffer_t *buffer)
+{
+    return buffer->end-buffer->write;
+}
+
+_pure_
+static inline size_t buffer_read_size (buffer_t *buffer)
+{
+    return buffer->write-buffer->read;
+}
+
+static inline void buffer_shift (buffer_t *buffer)
+{
+    if (buffer->read==buffer->write) {
+        buffer_format(buffer);
+    } else {
+        const uint8_t *src = PALIGN_DOWN(buffer->read);
+        const size_t size = ALIGN(buffer->write-src);
+        if (buffer->data+size<src) {
+            memcpy(buffer->data, src, size);
+            buffer->read  -= src-buffer->data;
+            buffer->write -= src-buffer->data;
+        }
+    }
+}
diff --git a/src/common-static.h b/src/common-static.h
deleted file mode 100644
index b50802c..0000000
--- a/src/common-static.h
+++ /dev/null
@@ -1,133 +0,0 @@
-#pragma once
-
-#include "common.h"
-
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-
-static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
-{
-    if (!dst || !src)
-        return 0;
-
-    size_t i;
-
-    for (i=0; i<len && src[i]; i++)
-        dst[i] = src[i];
-
-    dst[i] = 0;
-
-    return i;
-}
-
-_pure_
-static inline int str_empty (const char *restrict str)
-{
-    return !str || !str[0];
-}
-
-_pure_
-static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
-{
-    if (!sa || !sb)
-        return 1;
-
-    size_t i = 0;
-
-    while (sa[i]==sb[i])
-        if (!sa[i++])
-            return 0;
-
-    return i+1;
-}
-
-_pure_
-static inline size_t str_len (const char *restrict str)
-{
-    if (!str)
-        return 0;
-
-    size_t i = 0;
-
-    while (str[i])
-        i++;
-
-    return i;
-}
-
-static inline char *str_cat (const char *const strs[], size_t count)
-{
-    size_t size = 1;
-
-    for (size_t i=0; i<count; i++)
-        size += str_len(strs[i]);
-
-    char *str = malloc(size);
-
-    if (!str)
-        return NULL;
-
-    char *p = str;
-
-    for (size_t i=0; i<count; i++) {
-        size_t len = str_len(strs[i]);
-        memcpy(p, strs[i], len);
-        p += len;
-    }
-
-    p[0] = 0;
-
-    return str;
-}
-
-static inline void buffer_setup (buffer_t *buffer, void *data, size_t size)
-{
-    if (!data)
-        data = malloc(ALIGN(size));
-
-    buffer->data  = data;
-    buffer->read  = data;
-    buffer->write = data;
-    buffer->end   = data;
-    buffer->end  += size;
-}
-
-static inline void buffer_format (buffer_t *buffer)
-{
-    buffer->write = buffer->data;
-    buffer->read  = buffer->data;
-}
-
-_pure_
-static inline size_t buffer_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->data;
-}
-
-_pure_
-static inline size_t buffer_write_size (buffer_t *buffer)
-{
-    return buffer->end-buffer->write;
-}
-
-_pure_
-static inline size_t buffer_read_size (buffer_t *buffer)
-{
-    return buffer->write-buffer->read;
-}
-
-static inline void buffer_shift (buffer_t *buffer)
-{
-    if (buffer->read==buffer->write) {
-        buffer_format(buffer);
-    } else {
-        const uint8_t *src = PALIGN_DOWN(buffer->read);
-        const size_t size = ALIGN(buffer->write-src);
-        if (buffer->data+size<src) {
-            memcpy(buffer->data, src, size);
-            buffer->read  -= src-buffer->data;
-            buffer->write -= src-buffer->data;
-        }
-    }
-}
diff --git a/src/common.h b/src/common.h
index 9aa49a7..aa953eb 100644
--- a/src/common.h
+++ b/src/common.h
@@ -2,8 +2,11 @@
 
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
 
-#define COUNT(x) (sizeof(x)/sizeof(x[0]))
+#define COUNT(x)       (sizeof(x)/sizeof(x[0]))
 
 #define ALIGN_SIZE     (1<<4)
 #define ALIGN_MASK     (ALIGN_SIZE-1)
@@ -26,15 +29,6 @@
 #define _const_        __attribute__ ((const))
 #define _align_(...)   __attribute__ ((aligned(__VA_ARGS__)))
 
-typedef struct buffer buffer_t;
-
-struct buffer {
-    uint8_t *data;
-    uint8_t *read;
-    uint8_t *write;
-    uint8_t *end;
-};
-
 int  gt_print (const char *, ...) _printf_(1,2);
 void gt_log   (const char *, ...) _printf_(1,2);
 void gt_fatal (const char *, ...) _printf_(1,2) _noreturn_;
diff --git a/src/db.c b/src/db.c
index a5949cf..8c04c8f 100644
--- a/src/db.c
+++ b/src/db.c
@@ -1,5 +1,7 @@
+#include "common.h"
+
 #include "db.h"
-#include "common-static.h"
+#include "str.h"
 
 #define CBIT(X)      (1&(intptr_t)(X))
 #define CBIT_PTR(X)  (uint8_t *)(1|(intptr_t)(X))
diff --git a/src/ip-static.h b/src/ip.h
similarity index 100%
rename from src/ip-static.h
rename to src/ip.h
diff --git a/src/main.c b/src/main.c
index 003d973..9fa2b27 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,11 +1,19 @@
+#include "common.h"
+
+#include "buffer.h"
+#include "ip.h"
+#include "str.h"
+#include "option.h"
+#include "tun.h"
+#include "db.h"
+
 #include <inttypes.h>
 #include <limits.h>
 #include <stdio.h>
 #include <signal.h>
-#include <string.h>
 #include <poll.h>
+#include <fcntl.h>
 #include <sys/time.h>
-#include <sys/fcntl.h>
 #include <sys/stat.h>
 
 #ifndef __FAVOR_BSD
@@ -27,13 +35,6 @@
 
 #include <sodium.h>
 
-#include "common-static.h"
-#include "ip-static.h"
-
-#include "option.h"
-#include "tun.h"
-#include "db.h"
-
 #ifndef O_CLOEXEC
 #define O_CLOEXEC 0
 #endif
diff --git a/src/option.c b/src/option.c
index 7af7b52..014187b 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1,9 +1,7 @@
-#include "common-static.h"
-
-#include <stdio.h>
-#include <stdlib.h>
+#include "common.h"
 
 #include "option.h"
+#include "str.h"
 
 int option_str (void *data, int argc, char **argv)
 {
diff --git a/src/str.h b/src/str.h
new file mode 100644
index 0000000..7300ed6
--- /dev/null
+++ b/src/str.h
@@ -0,0 +1,78 @@
+#pragma once
+
+#include "common.h"
+
+static inline size_t str_cpy (char *restrict dst, const char *restrict src, size_t len)
+{
+    if (!dst || !src)
+        return 0;
+
+    size_t i;
+
+    for (i=0; i<len && src[i]; i++)
+        dst[i] = src[i];
+
+    dst[i] = 0;
+
+    return i;
+}
+
+_pure_
+static inline int str_empty (const char *restrict str)
+{
+    return !str || !str[0];
+}
+
+_pure_
+static inline size_t str_cmp (const char *restrict sa, const char *restrict sb)
+{
+    if (!sa || !sb)
+        return 1;
+
+    size_t i = 0;
+
+    while (sa[i]==sb[i])
+        if (!sa[i++])
+            return 0;
+
+    return i+1;
+}
+
+_pure_
+static inline size_t str_len (const char *restrict str)
+{
+    if (!str)
+        return 0;
+
+    size_t i = 0;
+
+    while (str[i])
+        i++;
+
+    return i;
+}
+
+static inline char *str_cat (const char *const strs[], size_t count)
+{
+    size_t size = 1;
+
+    for (size_t i=0; i<count; i++)
+        size += str_len(strs[i]);
+
+    char *str = malloc(size);
+
+    if (!str)
+        return NULL;
+
+    char *p = str;
+
+    for (size_t i=0; i<count; i++) {
+        size_t len = str_len(strs[i]);
+        memcpy(p, strs[i], len);
+        p += len;
+    }
+
+    p[0] = 0;
+
+    return str;
+}
diff --git a/src/tun.c b/src/tun.c
index 4cf3fbb..ea7dabb 100644
--- a/src/tun.c
+++ b/src/tun.c
@@ -1,7 +1,8 @@
-#include "common-static.h"
-#include "ip-static.h"
+#include "common.h"
 
 #include "tun.h"
+#include "str.h"
+#include "ip.h"
 
 #include <stdio.h>
 #include <fcntl.h>