tcpdump: add patch for nommu systems

[Peter: slightly tweak patch]
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/tcpdump/tcpdump-4.1.1-vfork.patch

@@ -0,0 +1,127 @@
+https://sourceforge.net/tracker/?func=detail&aid=3120897&group_id=53066&atid=469575
+
+From 6f8927c609d1f986a45010b7acae0eb570668642 Mon Sep 17 00:00:00 2001
+From: Mike Frysinger <vapier@gentoo.org>
+Date: Sat, 27 Nov 2010 17:18:05 -0500
+Subject: [PATCH] add support for nommu systems
+
+Rather than hardcode the WIN32 define, add proper fork checks to the
+configure script and check those.  This fixes building for nommu systems
+which lack the fork function.
+
+While we're here though, add support for this functionality via vfork
+so that it does work on nommu systems.  And fix an old bug where we
+exit properly in the forked child when the exec failed instead of just
+returning to the calling code (which isn't expecting it).
+
+Signed-off-by: Mike Frysinger <vapier@gentoo.org>
+---
+
+--- tcpdump-4.0.0/config.h.in
++++ tcpdump-4.0.0/config.h.in
+@@ -151,6 +151,9 @@
+ /* Define to 1 if you have the <fcntl.h> header file. */
+ #undef HAVE_FCNTL_H
+ 
++/* Define to 1 if you have the `fork' function. */
++#undef HAVE_FORK
++
+ /* Define to 1 if you have the `getnameinfo' function. */
+ #undef HAVE_GETNAMEINFO
+ 
+@@ -274,6 +277,9 @@
+ /* Define to 1 if you have the <unistd.h> header file. */
+ #undef HAVE_UNISTD_H
+ 
++/* Define to 1 if you have the `vfork' function. */
++#undef HAVE_VFORK
++
+ /* Define to 1 if you have the `vfprintf' function. */
+ #undef HAVE_VFPRINTF
+ 
+--- tcpdump-4.0.0/configure
++++ tcpdump-4.0.0/configure
+@@ -7976,7 +7976,7 @@ done
+ 
+ 
+ 
+-for ac_func in strftime
++for ac_func in fork vfork strftime
+ do
+ as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ { echo "$as_me:$LINENO: checking for $ac_func" >&5
+diff --git a/tcpdump.c b/tcpdump.c
+index c8da36b..abf3e69 100644
+--- a/tcpdump.c
++++ b/tcpdump.c
+@@ -1250,8 +1250,10 @@ main(int argc, char **argv)
+ 	(void)setsignal(SIGPIPE, cleanup);
+ 	(void)setsignal(SIGTERM, cleanup);
+ 	(void)setsignal(SIGINT, cleanup);
+-	(void)setsignal(SIGCHLD, child_cleanup);
+ #endif /* WIN32 */
++#if defined(HAVE_FORK) || defined(HAVE_VFORK)
++	(void)setsignal(SIGCHLD, child_cleanup);
++#endif
+ 	/* Cooperate with nohup(1) */
+ #ifndef WIN32	
+ 	if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
+@@ -1464,13 +1466,13 @@ cleanup(int signo _U_)
+   On windows, we do not use a fork, so we do not care less about
+   waiting a child processes to die
+  */
+-#ifndef WIN32
++#if defined(HAVE_FORK) || defined(HAVE_VFORK)
+ static RETSIGTYPE
+ child_cleanup(int signo _U_)
+ {
+   wait(NULL);
+ }
+-#endif /* WIN32 */
++#endif /* HAVE_FORK || HAVE_VFORK */
+ 
+ static void
+ info(register int verbose)
+@@ -1514,11 +1516,15 @@ info(register int verbose)
+ 	infoprint = 0;
+ }
+ 
+-#ifndef WIN32
++#if defined(HAVE_FORK) || defined(HAVE_VFORK)
+ static void
+ compress_savefile(const char *filename)
+ {
++# ifdef HAVE_FORK
+ 	if (fork())
++# else
++	if (vfork())
++# endif
+ 		return;
+ 	/*
+ 	 * Set to lowest priority so that this doesn't disturb the capture
+@@ -1534,15 +1540,20 @@ compress_savefile(const char *filename)
+ 			zflag,
+ 			filename,
+ 			strerror(errno));
++# ifdef HAVE_FORK
++	exit(1);
++# else
++	_exit(1);
++# endif
+ }
+-#else  /* WIN32 */
++#else  /* HAVE_FORK || HAVE_VFORK */
+ static void
+ compress_savefile(const char *filename)
+ {
+ 	fprintf(stderr,
+-		"compress_savefile failed. Functionality not implemented under windows\n");
++		"compress_savefile failed. Functionality not implemented under your system\n");
+ }
+-#endif /* WIN32 */
++#endif /* HAVE_FORK || HAVE_VFORK */
+ 
+ static void
+ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
+-- 
+1.7.3.1