very old code commited, ymmv

CheckResolv/Makefile

@@ -0,0 +1,60 @@
+#-------------------------------------------------------------------
+#
+#	CheckResolv
+#
+#	editable configuration variables:
+
+DESTDIR = /usr/local
+COPT    = -g -ansi -Wall
+
+#
+#	you can now compile with "make checkresolv" and install it
+#	with "su -c 'make install'"
+#
+#-------------------------------------------------------------------
+
+VERSION=0.25
+
+all:	
+	@echo
+	@echo "   may be you can read (and edit) the Makefile before"
+	@echo "   trying to compile and run that kludge..."
+	@echo
+	@echo "   for impatients: try \"make checkresolv\""
+	@echo
+
+checkresolv.o:	checkresolv.c Makefile fonctions.h
+	gcc $(COPT) -c -DVERSION=\"$(VERSION)\" -DTRACE=0  $<
+
+fonctions.o:	fonctions.c Makefile fonctions.h
+	gcc $(COPT) -c -DVERSION=\"$(VERSION)\" -DTRACE=0  $<
+
+checkresolv: checkresolv.o fonctions.o
+	gcc $(COPT) $^ -o $@
+
+#-------------------------------------------------------------------
+#
+#	install procedure is _also_ quick and dirty
+#
+install:
+	install --strip checkresolv $(DESTDIR)/bin
+	install checkresolv.man $(DESTDIR)/man/man1/checkresolv.1
+
+#-------------------------------------------------------------------
+
+FILES=*.c *.h Makefile CHANGELOG README TODO checkresolv.man *.html
+
+TARNAME=checkresolv-$(VERSION).tar.gz
+
+tarball:  $(FILES)
+	@echo "Tarball is" $(TARNAME)
+	@ls $^ > MANIFEST ; \
+	( cd .. ; \
+	tar zcvf $(TARNAME) `sed 's/^/CheckResolv\//' CheckResolv/MANIFEST` )
+	@date >> tarball
+	@wc -c ../$(TARNAME)
+
+lines:	$(FILES)
+	wc $(FILES) | sort -n
+
+#-------------------------------------------------------------------

CheckResolv/README.md

@@ -0,0 +1,21 @@
+```
+		CheckResolv
+		===========
+
+	This is a quick and dirty hack, built for chasing
+	a LPRng latency problem. Usage is very simple:
+ 	you give a hostname or an IP addr, and the soft
+	try a few lookup and/or reverse lookup.
+
+
+	Options are:
+		-V	display version
+		-r	do a reverse lookup
+		-v	increase verbosity
+		-e	print relateds env vars
+		-t	display time op operations
+	
+
+	Have a good life, don't release CO2 in the Ternet...
+
+```

CheckResolv/TODO

@@ -0,0 +1,12 @@
+    This is the TODO file for CheckResolv
+    -------------------------------------
+
+ - virer les GNUismes du Makefile
+ - check for potentials buffers overflows
+ - write a really cut manpage
+
+ - add a function to analyze /etc/resolv.conf
+ - add a function to check /etc/hosts
+
+ - build a fonction for detect DNS used by the resolver.
+

CheckResolv/checkresolv.c

@@ -0,0 +1,238 @@
+/*
+ *		CheckResolv
+ *		===========
+ *
+ *	quick and dirty debugging hack.
+ *
+ */
+
+#include  <stdio.h>
+#include  <unistd.h>
+#include  <stdlib.h>
+#define __USE_BSD
+#include  <string.h>
+/* #undef __USE_BSD */
+#include  <sys/time.h>
+#include  <getopt.h>
+
+#define __USE_MISC
+#include  <netdb.h>			/* herror ? */
+
+#include  <sys/socket.h>
+#include  <netinet/in.h>
+#include  <arpa/inet.h>
+
+#include  "fonctions.h"
+
+char * strdup(char *);			/* DIRTY HACK */
+
+/* ------------------------------------------------------------ */
+/*	quick and dirty global variables			*/
+
+int	verbose = 0;
+int	do_reverse = 0;
+int	do_environ = 0;
+int	do_timing = 0;	
+
+/* ------------------------------------------------------------ */
+/* parameter '*txt' is not used 				*/
+int	print_hostent(struct hostent *ph, char *txt)
+{
+char		*ptr, **pptr;
+
+printf("h_name:       %s\n", ph->h_name);
+
+pptr = ph->h_aliases;
+if (verbose) {
+	printf("h_aliases:    %p -> %p\n", pptr, *pptr);
+	}
+
+while ( (ptr = *(pptr)) != NULL ) {
+	printf("   alias:     %s\n", ptr);
+	pptr++;
+	}
+
+if (verbose) {
+	printf("h_addrtype:   %d\n", ph->h_addrtype);
+	printf("h_length:     %d\n", ph->h_length);
+	}
+
+print_ip((struct in_addr **)ph->h_addr_list);	/* strange cast */
+
+return 0;
+}
+/* ------------------------------------------------------------ */
+/*
+ *	If we have a list of IP addr, we can try a 
+ *	reverse lookup, no ?
+ */
+int check_reverse(struct hostent *ph)
+{
+struct in_addr		**liste;
+struct in_addr		*addr;
+struct in_addr		l_addr;				/* Jules */
+struct hostent		*revph;
+int			nbre;
+double			t1 , t2;
+char			*ptmp;
+
+if (do_timing)	t1 = chronometre();
+
+nbre = 0;
+liste = (struct in_addr **)ph->h_addr_list;
+
+while (NULL != (addr = *liste++)) {
+	l_addr = *addr;					/* Jules */
+#if TRACE
+	fprintf(stderr, "---> %p  %p\n", addr, l_addr);
+#endif
+	revph = gethostbyaddr(&l_addr, ph->h_length, ph->h_addrtype);
+	if (NULL != revph) {
+		/* taking over hidden string vars  */
+		ptmp = strdup(inet_ntoa(l_addr));
+		if (NULL == ptmp) {
+			fprintf(stderr, "no memory in %s, line %d\n",
+							__FILE__, __LINE__);
+			abort();
+			}
+#if TRACE
+		fprintf(stderr, "%s:%d %p %p\n", __func__, __LINE__, 
+					ptmp, revph->h_name);
+#endif
+		printf("reverse %-16s -> %s\n", ptmp, revph->h_name); 
+		free(ptmp);
+		}
+	else	{
+		/* fprintf(stderr, "reverse ? wtf ?\n"); */
+		herror("reverse lookup");	/* this func is obsolete ! */
+		}
+	nbre++;
+	}
+
+if (do_timing) {
+	t2 = chronometre();
+	if (nbre > 1)
+		printf("reverse take %.3f s (%.3f s)\n", t2-t1, (t2-t1)/nbre);
+	else
+		printf("reverse take %.3f s.\n", t2-t1);
+	}
+
+return 0;
+}
+/* ------------------------------------------------------------ */
+struct hostent *direct_lookup(char *hostname)
+{
+struct hostent	*p_host;
+double		t1 , t2;
+int		foo;
+
+if (do_timing)	t1 = chronometre();
+p_host = gethostbyname(hostname);
+if (do_timing)	t2 = chronometre();
+
+if (p_host==NULL)
+	{
+	fprintf(stderr, "error %d on '%s'", h_errno, hostname);
+	herror(" ");
+	return NULL;
+	}
+
+foo = print_hostent(p_host, NULL);
+
+if (do_timing)	printf("gethostbyname take %.3f s.\n", t2 - t1);
+
+return p_host;
+}
+/* ------------------------------------------------------------ */
+int	analyse(char *nom, int flag)
+{
+struct hostent	*p_host;
+
+p_host = direct_lookup(nom);
+
+/*
+ *  new, 31 jan 2005, v 0.19
+ *	if the requested 'hostname' seems to be an ip address, can we 
+ *	force a valid reverse lookup ?
+ */
+if (is_IP_addr(nom) && !do_reverse)
+	{
+	fprintf(stderr, "* if %s is a valid ip addr, try the '-r' switch.\n",
+				nom);
+	} 
+
+if (do_reverse && (p_host!=NULL))
+	check_reverse(p_host);
+
+return 0;
+}
+/* ------------------------------------------------------------ */
+/*
+ *	Set some global flags, based on our environment
+ *	variable.
+ */
+void analyze_environ(void)
+{
+char	*ptr;
+
+ptr = getenv("CHECKRESOLV");
+if (ptr == NULL)
+	return;
+if ( ! strcmp("tech", ptr) ) {
+	do_reverse = 1;
+	do_timing = 1;
+	}
+if ( ! strcmp("all", ptr) ) {
+	do_reverse = 1;
+	do_timing = 1;
+	verbose = 1;
+	do_environ = 1;
+	}
+}
+/* ------------------------------------------------------------ */
+int main (int argc, char *argv[])
+{
+int		foo;
+
+char		* liste_opt = "vrhteV";
+int		option;
+
+if (argc == 1)		help_options();
+	
+while ((option=getopt(argc, argv, liste_opt)) != -1)
+	{
+	switch(option)
+		{
+		case 'v':	verbose++;		break;
+		case 'r':	do_reverse=1;		break;
+		case 'e':	do_environ=1;		break;
+		case 't':	do_timing=1;		break;
+		case 'h':	usage();		break;
+		case 'V':	version();		break;
+		}
+	}
+
+#if TRACE
+fprintf(stderr, "argc %d  optind %d\n", argc, optind);
+for (foo=optind; foo<argc; foo++)
+	{
+	fprintf(stderr, "     %4d %s\n", foo, argv[foo]);
+	}
+#endif
+
+/*
+ *	env vars can override command line options.
+ */
+analyze_environ();
+
+for (foo=optind; foo<argc; foo++)
+	{
+	printf("------------( %s \n", argv[foo]);
+	analyse(argv[foo], 0);
+	}
+
+if (do_environ)	print_envvars(0);
+
+return 0;
+}
+/* ------------------------------------------------------------ */

CheckResolv/checkresolv.html

@@ -0,0 +1,44 @@
+<html>
+<head>
+<title>CheckResolv</title>
+<meta name="keywords" content="resolver, BIND,  DNS, resolv.conf">
+</head>
+
+<body>
+
+<h1>CheckResolv</h1>
+
+<p>
+This is a <i>quick'n'dirty</i> tool for checking the configuration
+of your local resolver and/or DNS configuration. See the
+included manpage and source code for more explanations.
+</p>
+
+<h2>options</h2>
+
+<dl>   <dt>-V <dd>display version number and exit.
+       <dt>-h <dd>brief help on the command-line options.
+       <dt>-v <dd>display various useless messages.
+       <dt>-r <dd>do reverse lookup on IP address discovered.
+       <dt>-e <dd>show content of a few environment var resolver-related.
+       <dt>-t <dd>compute elapsed time of operation, not really accurate.
+</dl>
+
+<hr>
+<p>
+This software use only basic functions like <i>gethostbyname(3)</i>
+or <i>gethostbyaddr(3)</i>. Checkresolv use the more low-level
+of the resolver galaxy, so it works like any &quot;lambda&quot;
+application. Really nice when you have to catch a mysterious
+failure in a <small>LAMBDA</small> software.
+</p>
+
+<p>
+The environmemt variable <tt>CHECKRESOLV</tt> control the verbosity.
+A value of <tt>tech</tt> add the display of reverse lookup and timings.
+And setting to <tt>all</tt> give you all the bells'n'whistles needed
+by geeks.
+</p>
+
+</body>
+</html>

CheckResolv/checkresolv.man

@@ -0,0 +1,80 @@
+.TH CheckResolv 1 "2005 September" "various OS" "Tonton Th"
+
+.SH NAME
+checkresolv \- quick & dirty tool for checking sanity of resolver.
+
+.SH SYNOPSIS
+\fBcheckresolv\fP -V
+.br
+\fBcheckresolv\fP [options] host.name
+.br
+\fBcheckresolv\fP [options] 42.51.69.406
+
+.SH DESCRIPTION
+CheckResolv is a (not so) q'n'd tool for checking basic capacities and
+potentials bugs of your resolver configuration.
+I have started the dev of this thing when I was working hard on a remote
+nasty printing problems.
+It use only \fBgethostbyname\fP and \fBgethostbyaddr\fP functions,
+like any lambda applications.
+CheckResolv can also display environment variables who can modify the behaviour
+of this damned resolver, or give you some problems.
+
+.SH OPTIONS
+.B -V
+display version number and exit.
+.br
+.B -h
+brief help on the command-line options.
+.br
+.B -v
+display various useless messages.
+.br
+.B -r
+do reverse lookup on IP address discovered.
+.br
+.B -e
+show content of a few environment vars resolver-related.
+.br
+.B -t
+compute elapsed time of operation, not really accurate.
+
+.SH TIPS
+If you have a strange problem between two hosts, "don't panic". Take the time
+to compil CheckResolv on the two hosts, and run it with the -r option, first
+with the hostname, and after that, with the IP address.
+And do this two runs on the two hosts. So, you get four results.
+Now, use your brain...
+
+.SH CONFIG FILE
+All your config files are belong to us. In the futur, may be you can
+put a list of env vars to display in a file.
+
+.SH ENV VARS
+If the environment variable CHECKRESOLV is set to "tech", reverse lookup
+and timing are activated, very nice when your pop3 server take 42 seconds
+before you can get some silly answer.
+And "all" give you all the bells & whistles.
+This variable override command lines options.
+
+.SH SEE ALSO
+.BR resolver (5),
+.BR host (1),
+.BR dig (1),
+.BR nslookup (1)
+
+.SH BUGS
+Some are here, some are waiting in the dark. Hidden static storage is a pain.
+No IPv6 support. No Slackware package, no Debian package...
+
+.SH COMPILATION
+Currently (2005 march), this software was only tested on Slackware 10.0 and
+Debian Sarge, but it can
+compile 'fine' on others Linux or *BSD flavors. IRIX is also a valuable target,
+because my troll-master use it...
+
+.SH AUTHOR(S)
+Thierry (aka tth) Boudet, with help from @donis, Miod, Reynerie...
+
+
+

CheckResolv/fonctions.c

@@ -0,0 +1,167 @@
+/*
+ *		CheckResolv
+ *		===========
+ *	quick and dirty debugging hack.
+ *
+ *	a bunch of various undocumented functions.
+ */
+
+#include  <stdio.h>
+#include  <stdlib.h>
+#include  <string.h>
+#include  <ctype.h>
+#include  <sys/time.h>
+#include  <sys/types.h>
+#include  <sys/socket.h>
+#include  <netinet/in.h>
+#include  <netdb.h>
+#include  <arpa/inet.h>
+
+#include  "fonctions.h"
+
+/* ------------------------------------------------------------ */
+/*
+ *	return !0 if str seems to be a quadnumber ip address.
+ */
+int	is_IP_addr(char *str)
+{
+int	nbrdots, length, foo, flag;
+/* int	o[4]; */
+
+length = strlen(str);
+flag = nbrdots = 0;
+for (foo=0; foo<length; foo++)
+	{
+	if (str[foo]=='.')	nbrdots++;
+	else if ( ! isdigit(str[foo]) )
+		return 0;
+	}
+
+return nbrdots==3;
+}
+/*
+ *	warning, this func is a kludge.
+ */
+/* ------------------------------------------------------------ */
+double chronometre(void)
+{
+struct timeval		tv;
+int			foo;
+double			ftemps;
+
+foo = gettimeofday(&tv, NULL);
+if (foo) perror("get time of day");
+
+ftemps = (double)tv.tv_sec + ((double)tv.tv_usec/1e6);
+return ftemps;
+}
+/* ------------------------------------------------------------ */
+int	print_ip(struct in_addr **liste)
+{
+struct in_addr	*addr;
+
+if (liste==NULL)
+	{
+	fprintf(stderr, "print addrip (%s:%d): liste is NULL\n",
+					__FILE__, __LINE__);
+	exit(5);
+	}
+
+while ((addr = *liste++)!=NULL)
+	{
+	printf("ip:           %s", inet_ntoa(*addr));
+/*
+ *	mmmm, must resolve globals  vars...
+	if (verbose)
+		printf("   %8x", *addr);
+ */
+	printf("\n");
+	}
+
+return 0;
+}
+/* ------------------------------------------------------------ */
+static void print_onevar(char *name)
+{
+char	*ptr;
+
+if ((ptr=getenv(name)) == NULL)
+	printf("%-29s is not defined\n", name);
+else
+	printf("%-27s = '%s'\n", name, ptr);
+}
+
+struct envvars
+	{
+	char	*name;
+	char	*comment;
+	} envvars[] =
+{
+{	"HOSTNAME",		NULL	},
+{	"HOSTALIASES",		NULL	},
+{	"http_proxy",		NULL	},
+{	"ftp_proxy",		NULL	},
+{	"PRINTER",		NULL	},
+{	"RESOLV_HOST_CONF",	NULL	},
+{	"RESOLV_SERV_ORDER",	NULL	},
+{	"RESOLV_SPOOF_CHECK",	NULL	},
+{	"RESOLV_MULTI",		NULL	},
+{	"RESOLV_REORDER",	NULL	},
+{	"CHECKRESOLV",		NULL	},
+{	"TONTON_TH",		NULL	},
+{	NULL,		NULL	}
+};
+
+/*
+ *	by the way, if you know another interesting env vars in
+ *	the resolver context...
+ */
+
+int	print_envvars(int flags)
+{
+struct envvars	*pev;
+
+puts("");
+pev = envvars;
+while (pev->name != NULL)
+	{
+	print_onevar(pev->name);
+	pev++;
+	}
+
+return 0;
+}
+/* ------------------------------------------------------------ */
+void help_options(void)
+{
+fputs("checkresolv [-v] [-r] [-e] [-t] hostname|ipaddr\n", stderr);
+fputs("checkresolv -h : more help\n", stderr);
+fputs("checkresolv -V : print version\n", stderr);
+}
+/* ------------------------------------------------------------ */
+void usage(void)
+{
+fprintf(stderr, "***  CheckResolv  v %s  ***  by tth  ***\n", VERSION);
+fputs("Usage:\n", stderr);
+fputs("\tcheckresolv [options] hostname | @ip\n", stderr);
+fputs("\n", stderr);
+fputs("options:\n", stderr);
+fputs("\t-V:      display version number\n", stderr);
+fputs("\t-v:      increase verbosity\n", stderr);
+fputs("\t-r:      try a reverse lookup\n", stderr);
+fputs("\t-e:      print some env vars\n", stderr);
+fputs("\t-t:      print elapsed time\n", stderr);
+fputs("\n", stderr);
+fputs("environmemt variable:\n", stderr);
+fputs("\tname:    CHECKRESOLV\n", stderr);
+fputs("\tvalue:   \"tech\"  reverse-lookup and timing\n", stderr);
+fputs("\tvalue:   \"all\"   all the bells & whistles\n", stderr);
+fputs("\n", stderr);
+exit(0);
+}
+/* ------------------------------------------------------------ */
+void version(void)
+{
+printf("CheckResolv v %s by tth\n", VERSION);
+}
+/* ------------------------------------------------------------ */

CheckResolv/fonctions.h

@@ -0,0 +1,17 @@
+/*
+ *		CheckResolv
+ *		===========
+ *	quick and dirty debugging hack.
+ *
+ */
+
+int	is_IP_addr(char *str);
+double	chronometre(void);
+
+int	print_ip(struct in_addr **liste);
+
+void	help_options(void);
+void	usage(void);
+void	version(void);
+
+int	print_envvars(int flag);