Import sources from 2011-03-30 iso image

1 files changed, 132 insertions, 0 deletions

diff --git a/sys/src/cmd/cifs/ping.c b/sys/src/cmd/cifs/ping.c
new file mode 100755
index 000000000..0aaaaa7e8
--- /dev/null
+++ b/sys/src/cmd/cifs/ping.c
@@ -0,0 +1,132 @@
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#include <thread.h>
+#include <libsec.h>
+#include <9p.h>
+
+extern char *Debug;
+
+typedef struct Pingcache Pingcache;
+struct Pingcache {
+	Pingcache*next;
+	long	rtt;
+	char	*host;
+	long	expire;
+};
+
+typedef struct {
+	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];
+} Icmp;
+
+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,
+
+	Npings		= 8,
+	Payload		= 32,
+
+	Cachetime	= 60,
+};
+
+static Pingcache *Cache;
+
+/*
+ * We ignore the first result as that is probably bigger
+ * than expected due to IP sorting out the routing to the host
+ */
+int
+ping(char *host, int timeout)
+{
+	int rtt, fd, i, seq;
+	long now;
+	vlong then;
+	uchar buf[128];
+	Icmp *ip;
+	Pingcache *c;
+
+	now = time(nil);
+	for(c = Cache; c; c = c->next)
+		if(strcmp(c->host, host) == 0 && now < c->expire){
+			if(Debug && strstr(Debug, "dfs") != nil)
+				print("\t\tping host=%s timeout=%d - cache hit\n",
+					host, timeout);
+			return c->rtt;
+		}
+
+	rtt = -1;
+	ip = (Icmp*)buf;
+
+	if((fd = dial(netmkaddr(host, "icmp", "1"), 0, 0, 0)) == -1)
+		goto fail;
+
+	for(seq = 0; seq < Npings; seq++){
+		then = nsec();
+		for(i = Payload; i < sizeof buf; i++)
+			buf[i] = i + seq;
+		ip->type = EchoRequest;
+		ip->code = 0;
+		ip->seq[0] = seq;
+		ip->seq[1] = seq;
+		alarm(timeout);
+		if(write(fd, ip, sizeof buf) != sizeof buf ||
+		    read(fd, ip, sizeof buf) != sizeof buf)
+			goto fail;
+		alarm(0);
+		if(ip->type != EchoReply || ip->code != 0 ||
+		    ip->seq[0] != seq || ip->seq[1] != seq)
+			goto fail;
+		for(i = Payload; i < sizeof buf; i++)
+			if((uchar)buf[i] != (uchar)(i + seq))
+				goto fail;
+		rtt = (rtt + nsec() - then) / 2;
+	}
+fail:
+	if(fd != -1)
+		close(fd);
+
+	if(Debug && strstr(Debug, "dfs") != nil)
+		print("\t\tping host=%s timeout=%d rtt=%d - failed\n",
+			host, timeout, rtt);
+
+	/*
+	 * failures get cached too
+	 */
+	for(c = Cache; c; c = c->next)
+		if(strcmp(c->host, host) == 0)
+			break;
+	if(c == nil){
+		c = emalloc9p(sizeof(Pingcache));
+		c->host = estrdup9p(host);
+		c->next = Cache;
+		Cache = c;
+	}
+	c->rtt = rtt;
+	c->expire = now+Cachetime;
+	return rtt;
+}