/*
This file is part of GNUnet.
- Copyright (C) 2010 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2010 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
#define ICMP_TIME_EXCEEDED 11
#endif
+/**
+ * Call memcpy() but check for @a n being 0 first. In the latter
+ * case, it is now safe to pass NULL for @a src or @a dst.
+ * Unlike traditional memcpy(), returns nothing.
+ *
+ * @param dst destination of the copy, may be NULL if @a n is zero
+ * @param src source of the copy, may be NULL if @a n is zero
+ * @param n number of bytes to copy
+ */
+#define GNUNET_memcpy(dst,src,n) do { if (0 != n) { (void) memcpy (dst,src,n); } } while (0)
+
/**
* Must match IP given in the server.
*/
ip_pkt.dst_ip = other->s_addr;
ip_pkt.checksum =
htons (calc_checksum ((uint16_t *) & ip_pkt, sizeof (struct ip_header)));
- memcpy (&packet[off], &ip_pkt, sizeof (struct ip_header));
+ GNUNET_memcpy (&packet[off],
+ &ip_pkt,
+ sizeof (struct ip_header));
off += sizeof (struct ip_header);
icmp_pkt.type = ICMP_TIME_EXCEEDED;
icmp_pkt.code = 0;
icmp_pkt.checksum = 0;
icmp_pkt.unused = 0;
- memcpy (&packet[off], &icmp_pkt, sizeof (struct icmp_ttl_exceeded_header));
+ GNUNET_memcpy (&packet[off],
+ &icmp_pkt,
+ sizeof (struct icmp_ttl_exceeded_header));
off += sizeof (struct icmp_ttl_exceeded_header);
/* ip header of the presumably 'lost' udp packet */
ip_pkt.dst_ip = dummy.s_addr;
ip_pkt.checksum =
htons (calc_checksum ((uint16_t *) & ip_pkt, sizeof (struct ip_header)));
- memcpy (&packet[off], &ip_pkt, sizeof (struct ip_header));
+ GNUNET_memcpy (&packet[off],
+ &ip_pkt,
+ sizeof (struct ip_header));
off += sizeof (struct ip_header);
/* build UDP header */
udp_pkt.dst_port = htons (NAT_TRAV_PORT);
udp_pkt.length = htons (port);
udp_pkt.crc = 0;
- memcpy (&packet[off], &udp_pkt, sizeof (struct udp_header));
+ GNUNET_memcpy (&packet[off],
+ &udp_pkt,
+ sizeof (struct udp_header));
off += sizeof (struct udp_header);
/* set ICMP checksum */
((uint16_t *) & packet[sizeof (struct ip_header)],
sizeof (struct icmp_ttl_exceeded_header) +
sizeof (struct ip_header) + sizeof (struct udp_header)));
- memcpy (&packet[sizeof (struct ip_header)], &icmp_pkt,
- sizeof (struct icmp_ttl_exceeded_header));
+ GNUNET_memcpy (&packet[sizeof (struct ip_header)],
+ &icmp_pkt,
+ sizeof (struct icmp_ttl_exceeded_header));
memset (&dst, 0, sizeof (dst));
dst.sin_family = AF_INET;
ip_pkt.dst_ip = other->s_addr;
ip_pkt.checksum =
htons (calc_checksum ((uint16_t *) & ip_pkt, sizeof (struct ip_header)));
- memcpy (&packet[off], &ip_pkt, sizeof (struct ip_header));
+ GNUNET_memcpy (&packet[off],
+ &ip_pkt,
+ sizeof (struct ip_header));
off = sizeof (ip_pkt);
/* icmp reply: time exceeded */
icmp_ttl.code = 0;
icmp_ttl.checksum = 0;
icmp_ttl.unused = 0;
- memcpy (&packet[off], &icmp_ttl, sizeof (struct icmp_ttl_exceeded_header));
+ GNUNET_memcpy (&packet[off],
+ &icmp_ttl,
+ sizeof (struct icmp_ttl_exceeded_header));
off += sizeof (struct icmp_ttl_exceeded_header);
/* ip header of the presumably 'lost' udp packet */
ip_pkt.checksum = 0;
ip_pkt.checksum =
htons (calc_checksum ((uint16_t *) & ip_pkt, sizeof (struct ip_header)));
- memcpy (&packet[off], &ip_pkt, sizeof (struct ip_header));
+ GNUNET_memcpy (&packet[off],
+ &ip_pkt,
+ sizeof (struct ip_header));
off += sizeof (struct ip_header);
icmp_echo.type = ICMP_ECHO;
icmp_echo.checksum = 0;
icmp_echo.checksum =
htons (calc_checksum
- ((uint16_t *) & icmp_echo, sizeof (struct icmp_echo_header)));
- memcpy (&packet[off], &icmp_echo, sizeof (struct icmp_echo_header));
+ ((uint16_t *) &icmp_echo, sizeof (struct icmp_echo_header)));
+ GNUNET_memcpy (&packet[off],
+ &icmp_echo,
+ sizeof (struct icmp_echo_header));
/* no go back to calculate ICMP packet checksum */
off = sizeof (struct ip_header);
((uint16_t *) & packet[off],
sizeof (struct icmp_ttl_exceeded_header) +
sizeof (struct ip_header) + sizeof (struct icmp_echo_header)));
- memcpy (&packet[off], &icmp_ttl, sizeof (struct icmp_ttl_exceeded_header));
+ GNUNET_memcpy (&packet[off],
+ &icmp_ttl,
+ sizeof (struct icmp_ttl_exceeded_header));
/* prepare for transmission */
memset (&dst, 0, sizeof (dst));