ncd: modules: add implode

blog_channels.txt

@@ -118,3 +118,4 @@ ncd_parse 4
 ncd_valuemetic 4
 ncd_file 4
 ncd_netmask 4
+ncd_implode 4

generated/blog_channel_ncd_implode.h

@@ -0,0 +1,4 @@
+#ifdef BLOG_CURRENT_CHANNEL
+#undef BLOG_CURRENT_CHANNEL
+#endif
+#define BLOG_CURRENT_CHANNEL BLOG_CHANNEL_ncd_implode

generated/blog_channels_defines.h

@@ -118,4 +118,5 @@
 #define BLOG_CHANNEL_ncd_valuemetic 117
 #define BLOG_CHANNEL_ncd_file 118
 #define BLOG_CHANNEL_ncd_netmask 119
-#define BLOG_NUM_CHANNELS 120
+#define BLOG_CHANNEL_ncd_implode 120
+#define BLOG_NUM_CHANNELS 121

generated/blog_channels_list.h

@@ -118,3 +118,4 @@
 {.name = "ncd_valuemetic", .loglevel = 4},
 {.name = "ncd_file", .loglevel = 4},
 {.name = "ncd_netmask", .loglevel = 4},
+{.name = "ncd_implode", .loglevel = 4},

ncd/CMakeLists.txt

@@ -110,6 +110,7 @@ add_executable(badvpn-ncd
     modules/valuemetic.c
     modules/file.c
     modules/netmask.c
+    modules/implode.c
     ${NCD_ADDITIONAL_SOURCES}
 )
 target_link_libraries(badvpn-ncd system flow flowextra dhcpclient arpprobe ncdconfig ncdvalue udevmonitor ncdinterfacemonitor ncdrequest)

ncd/modules/implode.c

@@ -0,0 +1,167 @@
+/**
+ * @file implode.c
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the
+ *    names of its contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * @section DESCRIPTION
+ * 
+ * Synopsis:
+ *   implode(string glue, list(string) pieces)
+ * 
+ * Variables:
+ *   string (empty) - concatenation of strings in 'pieces', with 'glue' in between
+ *                    every two elements.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <misc/expstring.h>
+#include <ncd/NCDModule.h>
+
+#include <generated/blog_channel_ncd_implode.h>
+
+#define ModuleLog(i, ...) NCDModuleInst_Backend_Log((i), BLOG_CURRENT_CHANNEL, __VA_ARGS__)
+
+struct instance {
+    NCDModuleInst *i;
+    char *result;
+    size_t result_len;
+};
+
+static void func_new (NCDModuleInst *i)
+{
+    // allocate structure
+    struct instance *o = malloc(sizeof(*o));
+    if (!o) {
+        ModuleLog(i, BLOG_ERROR, "malloc failed");
+        goto fail0;
+    }
+    o->i = i;
+    NCDModuleInst_Backend_SetUser(i, o);
+    
+    // read arguments
+    NCDValue *glue_arg;
+    NCDValue *pieces_arg;
+    if (!NCDValue_ListRead(i->args, 2, &glue_arg, &pieces_arg)) {
+        ModuleLog(i, BLOG_ERROR, "wrong arity");
+        goto fail1;
+    }
+    if (!NCDValue_IsString(glue_arg) || !NCDValue_IsList(pieces_arg)) {
+        ModuleLog(i, BLOG_ERROR, "wrong type");
+        goto fail1;
+    }
+    
+    // init result string
+    ExpString str;
+    if (!ExpString_Init(&str)) {
+        ModuleLog(i, BLOG_ERROR, "ExpString_Init failed");
+        goto fail1;
+    }
+    
+    for (NCDValue *piece = NCDValue_ListFirst(pieces_arg); piece; piece = NCDValue_ListNext(pieces_arg, piece)) {
+        // check piece type
+        if (!NCDValue_IsString(piece)) {
+            ModuleLog(i, BLOG_ERROR, "wrong piece type");
+            goto fail2;
+        }
+        
+        // append glue
+        if (piece != NCDValue_ListFirst(pieces_arg)) {
+            if (!ExpString_AppendBinary(&str, NCDValue_StringValue(glue_arg), NCDValue_StringLength(glue_arg))) {
+                ModuleLog(i, BLOG_ERROR, "ExpString_AppendBinary failed");
+                goto fail2;
+            }
+        }
+        
+        // append piece
+        if (!ExpString_AppendBinary(&str, NCDValue_StringValue(piece), NCDValue_StringLength(piece))) {
+            ModuleLog(i, BLOG_ERROR, "ExpString_AppendBinary failed");
+            goto fail2;
+        }
+    }
+    
+    // store result
+    o->result = ExpString_Get(&str);
+    o->result_len = ExpString_Length(&str);
+    
+    // signal up
+    NCDModuleInst_Backend_Up(i);
+    return;
+    
+fail2:
+    ExpString_Free(&str);
+fail1:
+    free(o);
+fail0:
+    NCDModuleInst_Backend_SetError(i);
+    NCDModuleInst_Backend_Dead(i);
+}
+
+static void func_die (void *vo)
+{
+    struct instance *o = vo;
+    NCDModuleInst *i = o->i;
+    
+    // free result
+    free(o->result);
+    
+    // free structure
+    free(o);
+    
+    NCDModuleInst_Backend_Dead(i);
+}
+
+static int func_getvar (void *vo, const char *name, NCDValue *out_value)
+{
+    struct instance *o = vo;
+    
+    if (!strcmp(name, "")) {
+        if (!NCDValue_InitStringBin(out_value, o->result, o->result_len)) {
+            ModuleLog(o->i, BLOG_ERROR, "NCDValue_InitStringBin failed");
+            return 0;
+        }
+        
+        return 1;
+    }
+    
+    return 0;
+}
+
+static const struct NCDModule modules[] = {
+    {
+        .type = "implode",
+        .func_new = func_new,
+        .func_die = func_die,
+        .func_getvar = func_getvar
+    }, {
+        .type = NULL
+    }
+};
+
+const struct NCDModuleGroup ncdmodule_implode = {
+    .modules = modules
+};

ncd/modules/modules.h

@@ -99,6 +99,7 @@ extern const struct NCDModuleGroup ncdmodule_parse;
 extern const struct NCDModuleGroup ncdmodule_valuemetic;
 extern const struct NCDModuleGroup ncdmodule_file;
 extern const struct NCDModuleGroup ncdmodule_netmask;
+extern const struct NCDModuleGroup ncdmodule_implode;
 
 static const struct NCDModuleGroup *ncd_modules[] = {
     &ncdmodule_var,
@@ -166,6 +167,7 @@ static const struct NCDModuleGroup *ncd_modules[] = {
     &ncdmodule_valuemetic,
     &ncdmodule_file,
     &ncdmodule_netmask,
+    &ncdmodule_implode,
     NULL
 };