More libc5 fixups
 -Erik
diff --git a/traceroute.c b/traceroute.c
index f4c67cf..a3abd0a 100644
--- a/traceroute.c
+++ b/traceroute.c
@@ -81,6 +81,96 @@
 #include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 
+ 
+ /* It turns out that libc5 doesn't have proper icmp support
+ * built into it header files, so we have to supplement it */
+#if __GNU_LIBRARY__ < 5
+static const int ICMP_MINLEN = 8;				/* abs minimum */
+
+struct icmp_ra_addr
+{
+  u_int32_t ira_addr;
+  u_int32_t ira_preference;
+};
+
+
+struct icmp
+{
+  u_int8_t  icmp_type;	/* type of message, see below */
+  u_int8_t  icmp_code;	/* type sub code */
+  u_int16_t icmp_cksum;	/* ones complement checksum of struct */
+  union
+  {
+    u_char ih_pptr;		/* ICMP_PARAMPROB */
+    struct in_addr ih_gwaddr;	/* gateway address */
+    struct ih_idseq		/* echo datagram */
+    {
+      u_int16_t icd_id;
+      u_int16_t icd_seq;
+    } ih_idseq;
+    u_int32_t ih_void;
+
+    /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
+    struct ih_pmtu
+    {
+      u_int16_t ipm_void;
+      u_int16_t ipm_nextmtu;
+    } ih_pmtu;
+
+    struct ih_rtradv
+    {
+      u_int8_t irt_num_addrs;
+      u_int8_t irt_wpa;
+      u_int16_t irt_lifetime;
+    } ih_rtradv;
+  } icmp_hun;
+#define	icmp_pptr	icmp_hun.ih_pptr
+#define	icmp_gwaddr	icmp_hun.ih_gwaddr
+#define	icmp_id		icmp_hun.ih_idseq.icd_id
+#define	icmp_seq	icmp_hun.ih_idseq.icd_seq
+#define	icmp_void	icmp_hun.ih_void
+#define	icmp_pmvoid	icmp_hun.ih_pmtu.ipm_void
+#define	icmp_nextmtu	icmp_hun.ih_pmtu.ipm_nextmtu
+#define	icmp_num_addrs	icmp_hun.ih_rtradv.irt_num_addrs
+#define	icmp_wpa	icmp_hun.ih_rtradv.irt_wpa
+#define	icmp_lifetime	icmp_hun.ih_rtradv.irt_lifetime
+  union
+  {
+    struct
+    {
+      u_int32_t its_otime;
+      u_int32_t its_rtime;
+      u_int32_t its_ttime;
+    } id_ts;
+    struct
+    {
+      struct ip idi_ip;
+      /* options and then 64 bits of data */
+    } id_ip;
+    struct icmp_ra_addr id_radv;
+    u_int32_t   id_mask;
+    u_int8_t    id_data[1];
+  } icmp_dun;
+#define	icmp_otime	icmp_dun.id_ts.its_otime
+#define	icmp_rtime	icmp_dun.id_ts.its_rtime
+#define	icmp_ttime	icmp_dun.id_ts.its_ttime
+#define	icmp_ip		icmp_dun.id_ip.idi_ip
+#define	icmp_radv	icmp_dun.id_radv
+#define	icmp_mask	icmp_dun.id_mask
+#define	icmp_data	icmp_dun.id_data
+};
+
+#define	ICMP_MINLEN	8				/* abs minimum */
+#define	ICMP_UNREACH		3		/* dest unreachable, codes: */
+#define	ICMP_TIMXCEED		11		/* time exceeded, code: */
+#define	ICMP_TIMXCEED_INTRANS	0		/* ttl==0 in transit */
+#define	ICMP_UNREACH_NET	        0	/* bad net */
+#define	ICMP_UNREACH_HOST	        1	/* bad host */
+#define	ICMP_UNREACH_PROTOCOL	        2	/* bad protocol */
+#define	ICMP_UNREACH_PORT	        3	/* bad port */
+#define	ICMP_UNREACH_NEEDFRAG	        4	/* IP_DF caused drop */
+#define	ICMP_UNREACH_SRCFAIL	        5	/* src route failed */
+#endif
 
 
 #define MAXPACKET       65535   /* max ip packet size */