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RIOT/dist/tools/uhcpd/uhcpd.c 4.38 KB
a752c7ab   elopes   add first test an...
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  /*
   * Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License v2. See the file LICENSE for more details.
   */
  
  #define UHCP_MCAST_ADDR "ff15::ABCD"
  
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <stdio.h>
  #include <netdb.h>
  #include <net/if.h>
  #include <arpa/inet.h>
  
  #include "net/uhcp.h"
  
  char _prefix[16];
  unsigned _prefix_len;
  
  static const char *BIND_OPTION = "--bind-to-device";
  static void bind_to_device(int sock, const char *interface);
  
  int ipv6_addr_split(char *addr_str, char seperator, int _default)
  {
      char *sep = addr_str;
      while(*++sep) {
          if (*sep == seperator) {
              *sep++ = '\0';
              if (*sep) {
                  _default = atoi(sep);
              }
              break;
          }
      }
  
      return _default;
  }
  
  int main(int argc, char *argv[])
  {
      unsigned ifindex;
      unsigned _bind_to_device = 0;
  
      if (argc < 3) {
          fprintf(stderr, "usage: uhcpd <interface> <prefix/prefix_length> [%s]\n",
                  BIND_OPTION);
          exit(1);
      }
  
      ifindex = if_nametoindex(argv[1]);
      if (!ifindex) {
          fprintf(stderr, "error: invalid interface \"%s\"\n", argv[1]);
          exit(1);
      }
  
      _prefix_len = ipv6_addr_split(argv[2], '/', 64);
      if ((!inet_pton(AF_INET6, argv[2], _prefix)) || (_prefix_len > 128)) {
          fprintf(stderr, "error: cannot parse prefix\n");
          exit(1);
      }
  
      if (argc == 4) {
          if (strcmp(BIND_OPTION, argv[3])) {
              fprintf(stderr, "error: unkwown option\n");
              exit(1);
          }
          _bind_to_device = 1;
      }
  
      char *addr_str = UHCP_MCAST_ADDR;
  
      struct addrinfo hint;
      memset(&hint, 0, sizeof(hint));
      hint.ai_family = AF_INET6;
      hint.ai_socktype = SOCK_DGRAM;
      hint.ai_protocol = IPPROTO_UDP;
      hint.ai_flags |= AI_NUMERICHOST;
  
      struct addrinfo *mcast_addr;
      int res = getaddrinfo(addr_str, UHCP_PORT_STR,
                            &hint, &mcast_addr);
      if (res != 0) {
          perror("getaddrinfo()");
          exit(1);
      }
  
      int sock = socket(mcast_addr->ai_family, mcast_addr->ai_socktype,
                        mcast_addr->ai_protocol);
      if (sock < 0) {
          perror("socket() failed");
          exit(1);
      }
  
      if (_bind_to_device) {
          bind_to_device(sock, argv[1]);
      }
  
      if (bind(sock, mcast_addr->ai_addr, mcast_addr->ai_addrlen) < 0) {
          perror("bind() failed");
          exit(1);
      }
  
      /* join multicast group */
      struct ipv6_mreq mreq;
      memcpy(&mreq.ipv6mr_multiaddr,
             &((struct sockaddr_in6 *)mcast_addr->ai_addr)->sin6_addr,
             sizeof(struct in6_addr));
  
      mreq.ipv6mr_interface = ifindex;
  
      puts("Joining IPv6 multicast group...");
      if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
                     &mreq, sizeof(mreq)) < 0) {
          perror("setsockopt(IPV6_JOIN_GROUP) failed");
          exit(1);
      }
      freeaddrinfo(mcast_addr);
  
      char buf[2048];
      struct sockaddr_in6 src_addr;
      unsigned n = sizeof(src_addr);;
  
      puts("entering loop...");
      while(1) {
          int nbytes = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr*)&src_addr, &n);
          if (nbytes < 0) {
              perror("recvfrom() failed");
              continue;
          }
          uhcp_handle_udp((uint8_t *)buf, nbytes, (uint8_t *)&src_addr.sin6_addr, ntohs(src_addr.sin6_port), ifindex);
      }
  
      close(sock);
      exit(0);
  }
  
  int udp_sendto(uint8_t *buf, size_t len, uint8_t *dst, uint16_t dst_port, uhcp_iface_t iface)
  {
      struct sockaddr_in6 dst_addr;
      memset(&dst_addr, '\0', sizeof(dst_addr));
      dst_addr.sin6_family = AF_INET6;
      memcpy(&dst_addr.sin6_addr, dst, 16);
      dst_addr.sin6_port = htons(dst_port);
      dst_addr.sin6_scope_id = iface;
  
      int fd = socket(AF_INET6, SOCK_DGRAM, 0);
      if (fd == -1) {
          perror("creating send socket");
          return -1;
      }
  
      ssize_t res;
      if ((res = sendto(fd, buf, len, 0, (struct sockaddr *)&dst_addr, sizeof(dst_addr))) == -1) {
          perror("udp_sendto(): sendto()");
      }
  
      close(fd);
  
      return res;
  }
  
  /* Requires to be 'root', I didn't find another solution for the moment */
  static void bind_to_device(int sock, const char *interface)
  {
      if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE,
                     interface, IF_NAMESIZE) < 0 ) {
          perror("setsockopt(SO_BINDTODEVICE) failed");
          exit(1);
      }
  }