[Auditbeat] Package: Nullify Librpm's rpmsqEnable (elastic#11628)

Overrides the `rpmsqEnable` function in Librpm that sets and unsets signal traps. Hopefully, this will eliminate the residual test failures.

(cherry picked from commit e047de6)

CHANGELOG.next.asciidoc

@@ -35,6 +35,8 @@ https://github.com/elastic/beats/compare/v7.0.0-rc1...master[Check the HEAD diff
 
 *Auditbeat*
 
+- Package dataset: Nullify Librpm's rpmsqEnable. {pull}11628[11628]
+
 *Filebeat*
 
 - Fix `add_docker_metadata` source matching, using `log.file.path` field now. {pull}11577[11577]

x-pack/auditbeat/module/system/package/rpm_linux.go

@@ -14,7 +14,6 @@ import (
 	"unsafe"
 
 	"github.com/coreos/pkg/dlopen"
-	"github.com/joeshaw/multierror"
 )
 
 /*
@@ -25,7 +24,6 @@ import (
 #include <rpm/header.h>
 #include <rpm/rpmts.h>
 #include <rpm/rpmdb.h>
-#include <rpm/rpmsq.h>
 
 rpmts
 my_rpmtsCreate(void *f) {
@@ -113,27 +111,21 @@ my_rpmtsFree(void *f, rpmts ts) {
 // By default, librpm is going to trap various UNIX signals including SIGINT and SIGTERM
 // which will prevent Beats from shutting down correctly.
 //
-// This disables that behavior. We should be very dilligent in
+// This disables that behavior by nullifying rpmsqEnable. We should be very dilligent in
 // cleaning up in our use of librpm.
 //
 // More recent versions of librpm have a new function rpmsqSetInterruptSafety()
 // to do this, see below.
 //
 // See also:
 // - librpm traps signals and calls exit(1) to terminate the whole process incl. our Go code: https://github.com/rpm-software-management/rpm/blob/rpm-4.11.3-release/lib/rpmdb.c#L640
-// - has caused problems for gdb before, calling rpmsqEnable(_, NULL) is the workaround they also use: https://bugzilla.redhat.com/show_bug.cgi?id=643031
+// - has caused problems for gdb before, they also nullify rpmsqEnable: https://bugzilla.redhat.com/show_bug.cgi?id=643031
 // - the new rpmsqSetInterruptSafety(), unfortunately only available in librpm>=4.14.0 (CentOS 7 has 4.11.3): https://github.com/rpm-software-management/rpm/commit/56f49d7f5af7c1c8a3eb478431356195adbfdd25
-void
-my_disableLibrpmSignalTraps(void *f) {
-	int (*rpmsqEnable)(int, rpmsqAction_t);
-	rpmsqEnable = (int (*)(int, rpmsqAction_t))f;
-
-	// Disable all traps
-	rpmsqEnable(-SIGHUP, NULL);
-	rpmsqEnable(-SIGINT, NULL);
-	rpmsqEnable(-SIGTERM, NULL);
-	rpmsqEnable(-SIGQUIT, NULL);
-	rpmsqEnable(-SIGPIPE, NULL);
+extern int rpmsqEnable (int signum, void *handler);
+int
+rpmsqEnable (int signum, void *handler)
+{
+  return 0;
 }
 
 void
@@ -170,7 +162,6 @@ type cFunctions struct {
 	headerFree              unsafe.Pointer
 	rpmdbFreeIterator       unsafe.Pointer
 	rpmtsFree               unsafe.Pointer
-	rpmsqEnable             unsafe.Pointer
 	rpmsqSetInterruptSafety unsafe.Pointer
 }
 
@@ -249,16 +240,7 @@ func dlopenCFunctions() (*cFunctions, error) {
 
 	// Only available in librpm>=4.13.0
 	cFun.rpmsqSetInterruptSafety, err = librpm.GetSymbolPointer("rpmsqSetInterruptSafety")
-	if err != nil {
-		var err2 error
-		// Only available in librpm<4.14.0
-		cFun.rpmsqEnable, err2 = librpm.GetSymbolPointer("rpmsqEnable")
-		if err2 != nil {
-			var errs multierror.Errors
-			errs = append(errs, err, err2)
-			return nil, errs.Err()
-		}
-	}
+	// no error check
 
 	return &cFun, nil
 }
@@ -298,9 +280,6 @@ func listRPMPackages() ([]*Package, error) {
 	if mi == nil {
 		return nil, fmt.Errorf("Failed to get match iterator")
 	}
-	if cFun.rpmsqEnable != nil {
-		C.my_disableLibrpmSignalTraps(cFun.rpmsqEnable)
-	}
 	defer C.my_rpmdbFreeIterator(cFun.rpmdbFreeIterator, mi)
 
 	var packages []*Package