ncd: add BadVPN interface module

ncd/CMakeLists.txt

@@ -4,6 +4,7 @@ add_executable(badvpn-ncd
     NCDInterfaceMonitor.c
     NCDInterfaceModule.c
     interface_modules/interface_physical.c
+    interface_modules/interface_badvpn.c
 )
 target_link_libraries(badvpn-ncd system dhcpclient ncdconfig)
 

ncd/interface_modules/interface_badvpn.c

@@ -0,0 +1,204 @@
+/**
+ * @file interface_badvpn.c
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * This file is part of BadVPN.
+ * 
+ * BadVPN is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ * 
+ * BadVPN is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * 
+ * @section DESCRIPTION
+ * 
+ * BadVPN interface backend.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <misc/cmdline.h>
+#include <system/BProcess.h>
+#include <ncd/NCDInterfaceModule.h>
+#include <ncd/NCDIfConfig.h>
+
+struct instance {
+    NCDInterfaceModuleInst *i;
+    BProcess process;
+    int need_terminate;
+};
+
+static int build_cmdline (struct instance *o, CmdLine *c)
+{
+    if (!CmdLine_Init(c)) {
+        goto fail0;
+    }
+    
+    // find exec statement
+    struct NCDConfig_statements *exec_st = NCDConfig_find_statement(o->i->conf->statements, "badvpn.exec");
+    if (!exec_st) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "badvpn.exec missing");
+        goto fail1;
+    }
+    
+    // check arity
+    char *exec_arg;
+    if (!NCDConfig_statement_has_one_arg(exec_st, &exec_arg)) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "badvpn.exec: wrong arity");
+        goto fail1;
+    }
+    
+    // append to cmdline
+    if (!CmdLine_Append(c, exec_arg)) {
+        goto fail1;
+    }
+    
+    // append tapdev
+    if (!CmdLine_Append(c, "--tapdev") || !CmdLine_Append(c, o->i->conf->name)) {
+        goto fail1;
+    }
+    
+    // iterate arg statements
+    struct NCDConfig_statements *st = o->i->conf->statements;
+    while (st = NCDConfig_find_statement(st, "badvpn.arg")) {
+        // iterate arguments
+        struct NCDConfig_strings *arg = st->args;
+        while (arg) {
+            if (!CmdLine_Append(c, arg->value)) {
+                goto fail1;
+            }
+            
+            arg = arg->next;
+        }
+        
+        st = st->next;
+    }
+    
+    // terminate
+    if (!CmdLine_Finish(c)) {
+        goto fail1;
+    }
+    
+    return 1;
+    
+fail1:
+    CmdLine_Free(c);
+fail0:
+    return 0;
+}
+
+static void process_handler (struct instance *o, int normally, uint8_t normally_exit_status)
+{
+    NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "process terminated");
+    
+    // set not need terminate
+    o->need_terminate = 0;
+    
+    // report error
+    NCDInterfaceModuleInst_Backend_Error(o->i);
+    return;
+}
+
+static void * func_new (NCDInterfaceModuleInst *i)
+{
+    // allocate instance
+    struct instance *o = malloc(sizeof(*o));
+    if (!o) {
+        NCDInterfaceModuleInst_Backend_Log(i, BLOG_ERROR, "failed to allocate instance");
+        goto fail0;
+    }
+    
+    // init arguments
+    o->i = i;
+    
+    // create TAP device
+    if (!NCDIfConfig_make_tuntap(o->i->conf->name, NULL, 0)) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "failed to create TAP device");
+        goto fail1;
+    }
+    
+    // set device up
+    if (!NCDIfConfig_set_up(o->i->conf->name)) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "failed to set device up");
+        goto fail2;
+    }
+    
+    // build cmdline
+    CmdLine cl;
+    if (!build_cmdline(o, &cl)) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "failed to build cmdline");
+        goto fail2;
+    }
+    
+    // start process
+    if (!BProcess_Init(&o->process, o->i->manager, (BProcess_handler)process_handler, o, ((char **)cl.arr.v)[0], (char **)cl.arr.v)) {
+        NCDInterfaceModuleInst_Backend_Log(o->i, BLOG_ERROR, "BProcess_Init failed");
+        CmdLine_Free(&cl);
+        goto fail2;
+    }
+    
+    CmdLine_Free(&cl);
+    
+    // set need terminate
+    o->need_terminate = 1;
+    
+    // report up
+    NCDInterfaceModuleInst_Backend_Event(o->i, NCDINTERFACEMODULE_EVENT_UP);
+    
+    return o;
+    
+fail2:
+    NCDIfConfig_remove_tuntap(o->i->conf->name, 0);
+fail1:
+    free(o);
+fail0:
+    return NULL;
+}
+
+static void func_free (void *vo)
+{
+    struct instance *o = vo;
+    
+    // order process to terminate
+    if (o->need_terminate) {
+        BProcess_Terminate(&o->process);
+    }
+    
+    // free process
+    BProcess_Free(&o->process);
+    
+    // remove TAP device
+    NCDIfConfig_remove_tuntap(o->i->conf->name, 0);
+    
+    // free instance
+    free(o);
+}
+
+static void func_finish (void *vo)
+{
+    struct instance *o = vo;
+    ASSERT(o->need_terminate)
+    
+    // order process to terminate
+    BProcess_Terminate(&o->process);
+    
+    // set not need terminate
+    o->need_terminate = 0;
+}
+
+const struct NCDInterfaceModule ncd_interface_badvpn = {
+    .type = "badvpn",
+    .func_new = func_new,
+    .func_free = func_free,
+    .func_finish = func_finish
+};

ncd/ncd.c

@@ -62,10 +62,12 @@
 
 // interface modules
 extern const struct NCDInterfaceModule ncd_interface_physical;
+extern const struct NCDInterfaceModule ncd_interface_badvpn;
 
 // interface modules list
 const struct NCDInterfaceModule *interface_modules[] = {
     &ncd_interface_physical,
+    &ncd_interface_badvpn,
     NULL
 };