new goodies

1 files changed, 112 insertions, 0 deletions

diff --git a/src/cmd/ip/dhcpd/ping.c b/src/cmd/ip/dhcpd/ping.c
new file mode 100755
index 00000000..7fa7a424
--- /dev/null
+++ b/src/cmd/ip/dhcpd/ping.c
@@ -0,0 +1,112 @@
+#include <u.h>
+#include <libc.h>
+#include <ip.h>
+
+
+typedef struct Icmp Icmp;
+struct Icmp
+{
+	uchar	vihl;		/* Version and header length */
+	uchar	tos;		/* Type of service */
+	uchar	length[2];	/* packet length */
+	uchar	id[2];		/* Identification */
+	uchar	frag[2];	/* Fragment information */
+	uchar	ttl;		/* Time to live */
+	uchar	proto;		/* Protocol */
+	uchar	ipcksum[2];	/* Header checksum */
+	uchar	src[4];		/* Ip source */
+	uchar	dst[4];		/* Ip destination */
+	uchar	type;
+	uchar	code;
+	uchar	cksum[2];
+	uchar	icmpid[2];
+	uchar	seq[2];
+	uchar	data[1];
+};
+
+enum
+{			/* Packet Types */
+	EchoReply	= 0,
+	Unreachable	= 3,
+	SrcQuench	= 4,
+	EchoRequest	= 8,
+	TimeExceed	= 11,
+	Timestamp	= 13,
+	TimestampReply	= 14,
+	InfoRequest	= 15,
+	InfoReply	= 16,
+
+	ICMP_IPSIZE	= 20,
+	ICMP_HDRSIZE	= 8,
+};
+
+static void
+catch(void *a, char *msg)
+{
+	USED(a);
+	if(strstr(msg, "alarm"))
+		noted(NCONT);
+	else
+		noted(NDFLT);
+}
+
+#define MSG "dhcp probe"
+
+/*
+ *  make sure noone is using the address
+ */
+int
+icmpecho(uchar *a)
+{
+	int fd;
+	char buf[512];
+	Icmp *ip;
+	int i, n, len;
+	ushort sseq, x;
+	int rv;
+
+return 0;
+	rv = 0;
+
+	sprint(buf, "%I", a);
+	fd = dial(netmkaddr(buf, "icmp", "1"), 0, 0, 0);
+	if(fd < 0){
+		return 0;
+	}
+
+	sseq = getpid()*time(0);
+
+	ip = (Icmp*)buf;
+	notify(catch);
+	for(i = 0; i < 3; i++){
+		ip->type = EchoRequest;
+		ip->code = 0;
+		strcpy((char*)ip->data, MSG);
+		ip->seq[0] = sseq;
+		ip->seq[1] = sseq>>8;
+		len = ICMP_IPSIZE+ICMP_HDRSIZE+sizeof(MSG);
+
+		/* send a request */
+		if(write(fd, buf, len) < len)
+			break;
+
+		/* wait 1/10th second for a reply and try again */
+		alarm(100);
+		n = read(fd, buf, sizeof(buf));
+		alarm(0);
+		if(n <= 0)
+			continue;
+
+		/* an answer to our echo request? */
+		x = (ip->seq[1]<<8)|ip->seq[0];
+		if(n >= len)
+		if(ip->type == EchoReply)
+		if(x == sseq)
+		if(strcmp((char*)ip->data, MSG) == 0){
+			rv = 1;
+			break;
+		}
+	}
+	close(fd);
+	return rv;
+}