gluon-status-page-api: rewrite neighbours-batadv in C

package/gluon-status-page-api/Makefile

@@ -12,19 +12,17 @@ define Package/gluon-status-page-api
   SECTION:=gluon
   CATEGORY:=Gluon
   TITLE:=API for gluon-status-page
-  DEPENDS:=+gluon-core +uhttpd +gluon-neighbour-info +gluon-announced +libiwinfo-lua +luci-lib-jsonc
+  DEPENDS:=+gluon-core +uhttpd +gluon-neighbour-info +gluon-announced +libiwinfo +libjson-c
 endef
 
 define Build/Prepare
-endef
+	mkdir -p $(PKG_BUILD_DIR)
-
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
-define Build/Configure
-endef
-
-define Build/Compile
 endef
 
 define Package/gluon-status-page-api/install
+	$(INSTALL_DIR) $(1)/lib/gluon/status-page/www/cgi-bin/dyn
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/neighbours-batadv $(1)/lib/gluon/status-page/www/cgi-bin/dyn/
 	$(CP) ./files/* $(1)/
 endef
 

package/gluon-status-page-api/files/lib/gluon/status-page/www/cgi-bin/dyn/neighbours-batadv

@@ -1,32 +0,0 @@
-#!/usr/bin/lua
-
-local json = require 'luci.jsonc'
-local nixio = require 'nixio'
-
-function neighbours()
-  local neighbours = {}
-  local list = io.lines("/sys/kernel/debug/batman_adv/bat0/originators")
-  for line in list do
-    local mac1, lastseen, tq, mac2, ifname =
-      line:match("^([0-9a-f:]+) +(%d+%.%d+)s +%( *(%d+)%) +([0-9a-f:]+) +%[ *(.-)%]")
-
-    if mac1 ~= nil and mac1 == mac2 then
-      neighbours[mac1] = { tq = tonumber(tq)
-                         , lastseen = tonumber(lastseen)
-                         , ifname = ifname
-                         }
-    end
-  end
-
-  return neighbours
-end
-
-io.write("Access-Control-Allow-Origin: *\n")
-io.write("Content-type: text/event-stream\n\n")
-
-while true do
-  local neighbours = json.stringify(neighbours())
-  io.write("data: " .. neighbours .. "\n\n")
-  io.flush()
-  nixio.nanosleep(1, 0)
-end

package/gluon-status-page-api/src/Makefile

@@ -0,0 +1,7 @@
+CFLAGS += $(shell pkg-config --cflags json-c)
+LDFLAGS += $(shell pkg-config --libs json-c)
+
+all: neighbours-batadv
+
+neighbours-batadv: neighbours-batadv.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) -Wall -o $@ $^ $(LDLIBS)

package/gluon-status-page-api/src/neighbours-batadv.c

@@ -0,0 +1,65 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <json-c/json.h>
+#include <net/if.h>
+
+#define STR(x) #x
+#define XSTR(x) STR(x)
+
+static json_object *neighbours(void) {
+  struct json_object *obj = json_object_new_object();
+
+  FILE *f;
+
+  f = fopen("/sys/kernel/debug/batman_adv/bat0/originators" , "r");
+
+  if (f == NULL) {
+    perror("Can not open bat0/originators");
+    exit(1);
+  }
+
+  while (!feof(f)) {
+    char mac1[18];
+    char mac2[18];
+    char ifname[IF_NAMESIZE+1];
+    int tq;
+    double lastseen;
+
+    int count = fscanf(f, "%17s%*[\t ]%lfs%*[\t (]%d) %17s%*[[ ]%" XSTR(IF_NAMESIZE) "[^]]]", mac1, &lastseen, &tq, mac2, ifname);
+
+    if (count != 5)
+      continue;
+
+    if (strcmp(mac1, mac2) == 0) {
+      struct json_object *neigh = json_object_new_object();
+
+      json_object_object_add(neigh, "tq", json_object_new_int(tq));
+      json_object_object_add(neigh, "lastseen", json_object_new_double(lastseen));
+      json_object_object_add(neigh, "ifname", json_object_new_string(ifname));
+
+      json_object_object_add(obj, mac1, neigh);
+    }
+  }
+
+  fclose(f);
+
+  return obj;
+}
+
+int main(void) {
+  struct json_object *obj;
+
+  printf("Access-Control-Allow-Origin: *\n");
+  printf("Content-type: text/event-stream\n\n");
+
+  while (1) {
+    obj = neighbours();
+    printf("data: %s\n\n", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_PLAIN));
+    fflush(stdout);
+    json_object_put(obj);
+    sleep(1);
+  }
+
+  return 0;
+}