gluon-neighbour-info: query direct neighbours

This is a simple client for gluon-announced.

package/gluon-neighbour-info/Makefile

+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=gluon-neighbour-info
+PKG_VERSION:=1
+PKG_RELEASE:=1
+
+PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/gluon-neighbour-info
+  SECTION:=gluon
+  CATEGORY:=Gluon
+  TITLE:=neighbour-info
+  DEPENDS:=
+endef
+
+define Package/gluon-neighbour-info/description
+	Gluon community wifi mesh firmware framework: neighbour-info
+endef
+
+define Build/Prepare
+	mkdir -p $(PKG_BUILD_DIR)
+	$(CP) ./src/* $(PKG_BUILD_DIR)/
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+	CFLAGS="$(TARGET_CFLAGS)" CPPFLAGS="$(TARGET_CPPFLAGS)" $(MAKE) -C $(PKG_BUILD_DIR) $(TARGET_CONFIGURE_OPTS)
+endef
+
+define Package/gluon-neighbour-info/install
+	$(INSTALL_DIR) $(1)/usr/bin
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/gluon-neighbour-info $(1)/usr/bin/
+endef
+
+$(eval $(call BuildPackage,gluon-neighbour-info))

package/gluon-neighbour-info/src/Makefile

+all: gluon-neighbour-info
+
+gluon-neighbour-info: gluon-neighbour-info.c
+
+clean:
+	rm gluon-neighbour-info

package/gluon-neighbour-info/src/gluon-neighbour-info.c

+/*
+   Copyright (c) 2014, Nils Schneider <nils@nilsschneider.net>
+   All rights reserved.
+
+   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.
+
+   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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
+   */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+/*
+ * a destination address with interface identifier
+ * a port
+ * a requeststring
+ * a timeout
+ * a filter
+ */
+
+void usage() {
+  puts("Usage: gluon-neighbour-info [-h] [-s] -d <dest> -p <port> -i <if0> -r <request>");
+  puts("  -p <int>         UDP port");
+  puts("  -d <ip6>         multicast group, e.g. ff02:0:0:0:0:0:2:1001");
+  puts("  -i <string>      interface, e.g. eth0 ");
+  puts("  -r <string>      request, e.g. nodeinfo");
+  puts("  -s               output as server-sent events");
+  puts("  -h               this help\n");
+}
+
+int request(const int sock, const struct sockaddr_in6 *client_addr, const char *request, bool sse) {
+  ssize_t ret;
+  struct sockaddr_in6 node_addr;
+  socklen_t nodelen;
+  char buffer[8192];
+
+  ret = sendto(sock, request, strlen(request), 0, (struct sockaddr *)client_addr, sizeof(struct sockaddr_in6));
+
+  if (ret < 0) {
+    perror("Error in sendto()");
+    exit(EXIT_FAILURE);
+  }
+
+  nodelen = sizeof(client_addr);
+
+  struct timeval tv;
+  tv.tv_sec = 2;
+  tv.tv_usec = 0;
+  if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO,&tv,sizeof(tv)) < 0) {
+      perror("Error");
+  }
+
+  while (1) {
+    ret = recvfrom(sock, buffer, sizeof(buffer), 0, (struct sockaddr *)&node_addr, &nodelen);
+    if (ret < 0)
+      break;
+
+    if (sse)
+      fputs("event: neighbour\ndata: ", stdout);
+
+    fwrite(buffer, sizeof(char), ret, stdout);
+
+    if (sse)
+      fputs("\n\n", stdout);
+
+    fflush(stdout);
+  }
+
+  return 0;
+}
+
+int main(int argc, char **argv) {
+  int sock;
+  struct sockaddr_in6 client_addr = {};
+  char *request_string = NULL;
+  struct in6_addr mgroup_addr;
+
+  sock = socket(PF_INET6, SOCK_DGRAM, 0);
+
+  if (sock < 0) {
+    perror("creating socket");
+    exit(EXIT_FAILURE);
+  }
+
+  client_addr.sin6_family = AF_INET6;
+  client_addr.sin6_addr = in6addr_any;
+
+  opterr = 0;
+
+  int port_set = 0;
+  int destination_set = 0;
+  bool sse = false;
+
+  int c;
+  while ((c = getopt(argc, argv, "p:d:r:i:sh")) != -1)
+    switch (c) {
+      case 'p':
+        client_addr.sin6_port = htons(atoi(optarg));
+        break;
+      case 'd':
+        if (!inet_pton(AF_INET6, optarg, &client_addr.sin6_addr)) {
+          perror("Invalid IPv6 address. This message will probably confuse you");
+          exit(EXIT_FAILURE);
+        }
+        break;
+      case 'i':
+        client_addr.sin6_scope_id = if_nametoindex(optarg);
+        if (client_addr.sin6_scope_id == 0) {
+          perror("Can not use interface");
+          exit(EXIT_FAILURE);
+        }
+        break;
+      case 'r':
+        request_string = optarg;
+        break;
+      case 's':
+        sse = true;
+        break;
+      case 'h':
+        usage();
+        exit(EXIT_SUCCESS);
+        break;
+      default:
+        fprintf(stderr, "Invalid parameter %c ignored.\n", c);
+    }
+
+  if (request_string == NULL)
+    error(EXIT_FAILURE, 0, "No request string supplied");
+
+  if (sse)
+    fputs("Content-Type: text/event-stream\n\n", stdout);
+
+  request(sock, &client_addr, request_string, sse);
+
+  if (sse)
+    fputs("event: eot\ndata: null\n\n", stdout);
+
+  return EXIT_SUCCESS;
+}