fix(pkg): ported local builder to use cmake.

Signed-off-by: Federico Di Pierro <nierro92@gmail.com>

pkg/driverbuilder/builder/local.go

@@ -4,6 +4,7 @@ import (
 	_ "embed"
 	"fmt"
 	"github.com/falcosecurity/driverkit/pkg/kernelrelease"
+	"path"
 )
 
 // NOTE: since this is only used by local build,
@@ -63,12 +64,11 @@ func (l *LocalBuilder) TemplateData(c Config, kr kernelrelease.KernelRelease, _
 }
 
 func (l *LocalBuilder) GetModuleFullPath(c Config, kr kernelrelease.KernelRelease) string {
-	moduleFullPath := ModuleFullPath
 	if l.UseDKMS {
 		// When using dkms, we will use a GLOB to match the pattern; ModuleFullPath won't be used in the templated script anyway.
-		moduleFullPath = fmt.Sprintf("/var/lib/dkms/%s/%s/%s/%s/module/%s.*", c.DriverName, c.DriverVersion, kr.String(), kr.Architecture.ToNonDeb(), c.DriverName)
+		return fmt.Sprintf("/var/lib/dkms/%s/%s/%s/%s/module/%s.*", c.DriverName, c.DriverVersion, kr.String(), kr.Architecture.ToNonDeb(), c.DriverName)
 	}
-	return moduleFullPath
+	return path.Join(DriverDirectory, "build", "driver", fmt.Sprintf("%s.ko", c.DriverName))
 }
 
 func (l *LocalBuilder) GetDriverBuildDir() string {

pkg/driverbuilder/builder/templates/local.sh

@@ -30,12 +30,17 @@ rm -Rf /tmp/module-download
 mkdir -p /tmp/module-download
 
 curl --silent -SL {{ .ModuleDownloadURL }} | tar -xzf - -C /tmp/module-download
-mv /tmp/module-download/*/driver/* {{ .DriverBuildDir }}
+mv /tmp/module-download/*/* {{ .DriverBuildDir }}
+{{ end }}
 
-cp /tmp/module-Makefile {{ .DriverBuildDir }}/Makefile
-bash /tmp/fill-driver-config.sh {{ .DriverBuildDir }}
+{{ if or .BuildProbe (and  .BuildModule (not .UseDKMS)) }}
+echo "* Configuring sources with cmake"
+cd {{ .DriverBuildDir }}
+mkdir -p build && cd build
+cmake -DUSE_BUNDLED_DEPS=On -DCREATE_TEST_TARGETS=Off -DBUILD_LIBSCAP_GVISOR=Off -DBUILD_LIBSCAP_MODERN_BPF=Off -DENABLE_DRIVERS_TESTS=Off -DDRIVER_NAME={{ .ModuleDriverName }} -DBUILD_BPF=On ..
 {{ end }}
 
+
 {{ if .BuildModule }}
 {{ if .UseDKMS }}
 echo "* Building kmod with DKMS"
@@ -48,9 +53,7 @@ rm -Rf "/tmp/falco-dkms-make"
 {{ else }}
 echo "* Building kmod"
 # Build the module
-cd {{ .DriverBuildDir }}
-make CC={{ .GCCVersion }}
-mv {{ .ModuleDriverName }}.ko {{ .ModuleFullPath }}
+make CC={{ .GCCVersion }} driver
 strip -g {{ .ModuleFullPath }}
 # Print results
 modinfo {{ .ModuleFullPath }}
@@ -60,9 +63,8 @@ modinfo {{ .ModuleFullPath }}
 {{ if .BuildProbe }}
 echo "* Building eBPF probe"
 # Build the eBPF probe
-cd {{ .DriverBuildDir }}/bpf
-make
-ls -l probe.o
+make bpf
+ls -l driver/bpf/probe.o
 {{ end }}
 
 rm -Rf /tmp/module-download

pkg/driverbuilder/local.go

@@ -2,7 +2,6 @@ package driverbuilder
 
 import (
 	"bufio"
-	"bytes"
 	"context"
 	_ "embed"
 	"fmt"
@@ -51,37 +50,7 @@ func (lbp *LocalBuildProcessor) Start(b *builder.Build) error {
 	}
 	c := b.ToConfig()
 
-	// Prepare driver config template
-	bufFillDriverConfig := bytes.NewBuffer(nil)
-	err = renderFillDriverConfig(bufFillDriverConfig, driverConfigData{DriverVersion: c.DriverVersion, DriverName: c.DriverName, DeviceName: c.DeviceName})
-	if err != nil {
-		return err
-	}
-
-	// Prepare makefile template
-	objList, err := LoadMakefileObjList(c)
-	if err != nil {
-		return err
-	}
-	bufMakefile := bytes.NewBuffer(nil)
-	err = renderMakefile(bufMakefile, makefileData{ModuleName: c.DriverName, ModuleBuildDir: builder.DriverDirectory, MakeObjList: objList})
-	if err != nil {
-		return err
-	}
-
-	// Create all local files
-	files := []dockerCopyFile{
-		{"/tmp/module-Makefile", bufMakefile.String()},
-		{"/tmp/fill-driver-config.sh", bufFillDriverConfig.String()},
-	}
-	for _, file := range files {
-		if err = os.WriteFile(file.Name, []byte(file.Body), 0o755); err != nil {
-			return err
-		}
-		defer os.Remove(file.Name)
-	}
-
-	defer os.Remove(builder.DriverDirectory)
+	defer os.RemoveAll(builder.DriverDirectory)
 
 	// Load gcc versions from system
 	var gccs []string
@@ -107,7 +76,7 @@ func (lbp *LocalBuildProcessor) Start(b *builder.Build) error {
 		}
 	} else {
 		// We won't use it!
-		gccs = []string{"gcc"}
+		gccs = []string{"UNUSED"}
 	}
 
 	// Cannot fail
@@ -116,7 +85,7 @@ func (lbp *LocalBuildProcessor) Start(b *builder.Build) error {
 	vv.UseDKMS = lbp.useDKMS
 
 	modulePath := vv.GetModuleFullPath(c, kr)
-	probePath := path.Join(vv.GetDriverBuildDir(), "bpf", builder.ProbeFileName)
+	probePath := path.Join(vv.GetDriverBuildDir(), "build", "driver", "bpf", builder.ProbeFileName)
 	for _, gcc := range gccs {
 		vv.GccPath = gcc
 
@@ -151,18 +120,26 @@ func (lbp *LocalBuildProcessor) Start(b *builder.Build) error {
 				err = cmd.Wait()
 			}
 		}
-		if err == nil {
-			break
+
+		// If we built the probe, disable its build for subsequent attempts (with other available gccs)
+		if c.ProbeFilePath != "" {
+			if _, err = os.Stat(probePath); !os.IsNotExist(err) {
+				if err = copyDataToLocalPath(probePath, b.ProbeFilePath); err != nil {
+					return err
+				}
+				slog.With("path", b.ProbeFilePath).Info("eBPF probe available")
+				c.ProbeFilePath = ""
+			}
 		}
-		// If we received an error, perhaps we must just rebuilt the kmod.
+
+		// If we received an error, perhaps we just need to try another build for the kmod.
 		// Check if we were able to build anything.
 		koFiles, err := filepath.Glob(modulePath)
 		if err == nil && len(koFiles) > 0 {
+			// Since only kmod might need to get rebuilt
+			// with another gcc, break here if we actually built the kmod.
 			break
 		}
-		if _, err = os.Stat(probePath); !os.IsNotExist(err) {
-			c.ProbeFilePath = ""
-		}
 	}
 
 	if len(b.ModuleFilePath) > 0 {
@@ -177,14 +154,6 @@ func (lbp *LocalBuildProcessor) Start(b *builder.Build) error {
 		}
 		slog.With("path", b.ModuleFilePath).Info("kernel module available")
 	}
-
-	if len(b.ProbeFilePath) > 0 {
-		if err = copyDataToLocalPath(probePath, b.ProbeFilePath); err != nil {
-			return err
-		}
-		slog.With("path", b.ProbeFilePath).Info("eBPF probe available")
-	}
-
 	return nil
 }