From 396cfdfee8b3c5f5207b488d159b8677605a453f Mon Sep 17 00:00:00 2001
From: Vincent Bernat <bernat@luffy.cx>
Date: Tue, 1 May 2012 01:50:03 +0200
Subject: [PATCH] When running on valgrind, don't chroot or drop privileges

Valgrind documentation says:

  You are encouraged to copy the valgrind/*.h headers into your
  project's include directory, so your program doesn't have a
  compile-time dependency on Valgrind being installed. The Valgrind
  headers, unlike most of the rest of the code, are under a BSD-style
  license so you may include them without worrying about license
  incompatibility.

I don't like copying headers around. Therefore, there is an autoconf
check for valgrind headers.
---
 configure.ac |  1 +
 src/lldpd.h  |  6 ++++++
 src/priv.c   | 26 +++++++++++++++-----------
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/configure.ac b/configure.ac
index 32ca90b4..3c85065b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -102,6 +102,7 @@ AC_CHECK_HEADERS([ \
 @%:@include <arpa/inet.h>
 @%:@include <linux/if.h>
 ])
+AC_CHECK_HEADERS([valgrind/valgrind.h])
 
 AC_CACHE_SAVE
 
diff --git a/src/lldpd.h b/src/lldpd.h
index 97c8531b..0ecf4e93 100644
--- a/src/lldpd.h
+++ b/src/lldpd.h
@@ -21,6 +21,12 @@
 #  include <config.h>
 #endif
 
+#ifdef HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+#else
+# define RUNNING_ON_VALGRIND 0
+#endif
+
 #define _GNU_SOURCE 1
 #include <stdlib.h>
 #include <stddef.h>
diff --git a/src/priv.c b/src/priv.c
index 217cac9e..9e57532f 100644
--- a/src/priv.c
+++ b/src/priv.c
@@ -531,17 +531,21 @@ priv_init(char *chrootdir)
 	switch (monitored) {
 	case 0:
 		/* We are in the children, drop privileges */
-		if (chroot(chrootdir) == -1)
-			fatal("[priv]: unable to chroot");
-		if (chdir("/") != 0)
-			fatal("[priv]: unable to chdir");
-		gidset[0] = gid;
-		if (setresgid(gid, gid, gid) == -1)
-			fatal("[priv]: setresgid() failed");
-		if (setgroups(1, gidset) == -1)
-			fatal("[priv]: setgroups() failed");
-		if (setresuid(uid, uid, uid) == -1)
-			fatal("[priv]: setresuid() failed");
+		if (RUNNING_ON_VALGRIND)
+			LLOG_WARNX("[priv]: running on valgrind, keep privileges");
+		else {
+			if (chroot(chrootdir) == -1)
+				fatal("[priv]: unable to chroot");
+			if (chdir("/") != 0)
+				fatal("[priv]: unable to chdir");
+			gidset[0] = gid;
+			if (setresgid(gid, gid, gid) == -1)
+				fatal("[priv]: setresgid() failed");
+			if (setgroups(1, gidset) == -1)
+				fatal("[priv]: setgroups() failed");
+			if (setresuid(uid, uid, uid) == -1)
+				fatal("[priv]: setresuid() failed");
+		}
 		remote = pair[0];
 		close(pair[1]);
 		priv_ping();
-- 
2.39.5