From 130cc40fea6e7045eb61b9075eb8737f0384911f Mon Sep 17 00:00:00 2001
From: Daniel <dhaavi@users.noreply.github.com>
Date: Fri, 17 Nov 2023 12:21:10 +0100
Subject: [PATCH] Improve AppImage matching, even without ENV vars

---
 process/tags/appimage_unix.go | 147 ++++++++++++++++++++++++++++------
 1 file changed, 122 insertions(+), 25 deletions(-)

diff --git a/process/tags/appimage_unix.go b/process/tags/appimage_unix.go
index 37548242..b2f47750 100644
--- a/process/tags/appimage_unix.go
+++ b/process/tags/appimage_unix.go
@@ -1,8 +1,13 @@
 package tags
 
 import (
+	"bufio"
+	"bytes"
+	"os"
+	"regexp"
 	"strings"
 
+	"github.com/safing/portbase/log"
 	"github.com/safing/portbase/utils/osdetail"
 	"github.com/safing/portmaster/process"
 	"github.com/safing/portmaster/profile"
@@ -16,8 +21,14 @@ func init() {
 }
 
 const (
-	appImageName       = "AppImage"
-	appImagePathTagKey = "app-image-path"
+	appImageName          = "AppImage"
+	appImagePathTagKey    = "app-image-path"
+	appImageMountIDTagKey = "app-image-mount-id"
+)
+
+var (
+	appImageMountDirRegex         = regexp.MustCompile(`^/tmp/.mount_[^/]+`)
+	appImageMountNameExtractRegex = regexp.MustCompile(`^[A-Za-z0-9]+`)
 )
 
 // AppImageHandler handles AppImage processes on Unix systems.
@@ -34,36 +45,77 @@ func (h *AppImageHandler) TagDescriptions() []process.TagDescription {
 	return []process.TagDescription{
 		{
 			ID:          appImagePathTagKey,
-			Name:        "App Image Path",
+			Name:        "AppImage Path",
 			Description: "Path to the app image file itself.",
 		},
+		{
+			ID:          appImageMountIDTagKey,
+			Name:        "AppImage Mount ID",
+			Description: "Extracted ID from the AppImage mount name. Use AppImage Path instead, if available.",
+		},
 	}
 }
 
 // AddTags adds tags to the given process.
 func (h *AppImageHandler) AddTags(p *process.Process) {
-	// Get and verify AppImage location.
-	appImageLocation, ok := p.Env["APPIMAGE"]
-	if !ok {
-		return
-	}
-	appImageMountDir, ok := p.Env["APPDIR"]
-	if !ok {
-		return
-	}
-	// Check if the process path is in the mount dir.
-	if !strings.HasPrefix(p.Path, appImageMountDir) {
-		return
-	}
+	// Detect app image path via ENV vars.
+	func() {
+		// Get and verify AppImage location.
+		appImageLocation, ok := p.Env["APPIMAGE"]
+		if !ok || appImageLocation == "" {
+			return
+		}
+		appImageMountDir, ok := p.Env["APPDIR"]
+		if !ok || appImageMountDir == "" {
+			return
+		}
+		// Check if the process path is in the mount dir.
+		if !strings.HasPrefix(p.Path, appImageMountDir) {
+			return
+		}
 
-	// Add matching path for regular profile matching.
-	p.MatchingPath = appImageLocation
+		// Add matching path for regular profile matching.
+		p.MatchingPath = appImageLocation
 
-	// Add app image tags.
-	p.Tags = append(p.Tags, profile.Tag{
-		Key:   appImagePathTagKey,
-		Value: appImageLocation,
-	})
+		// Add app image tag.
+		p.Tags = append(p.Tags, profile.Tag{
+			Key:   appImagePathTagKey,
+			Value: appImageLocation,
+		})
+	}()
+
+	// Detect app image mount point.
+	func() {
+		// Check if binary path matches app image mount pattern.
+		mountDir := appImageMountDirRegex.FindString(p.Path)
+		if mountDir == "" {
+			return
+		}
+
+		// Get mount name of mount dir.
+		// Also, this confirm this is actually a mounted dir.
+		mountName, err := getAppImageMountName(mountDir)
+		if err != nil {
+			log.Debugf("process/tags: failed to get mount name: %s", err)
+			return
+		}
+		if mountName == "" {
+			return
+		}
+
+		// Extract a usable ID from the mount name.
+		mountName, _ = strings.CutPrefix(mountName, "gearlever_")
+		mountName = appImageMountNameExtractRegex.FindString(mountName)
+		if mountName == "" {
+			return
+		}
+
+		// Add app image tag.
+		p.Tags = append(p.Tags, profile.Tag{
+			Key:   appImageMountIDTagKey,
+			Value: mountName,
+		})
+	}()
 }
 
 // CreateProfile creates a profile based on the tags of the process.
@@ -72,12 +124,13 @@ func (h *AppImageHandler) CreateProfile(p *process.Process) *profile.Profile {
 	if tag, ok := p.GetTag(appImagePathTagKey); ok {
 		return profile.New(&profile.Profile{
 			Source:              profile.SourceLocal,
-			Name:                osdetail.GenerateBinaryNameFromPath(tag.Value),
+			Name:                osdetail.GenerateBinaryNameFromPath(p.Path),
 			PresentationPath:    p.Path,
 			UsePresentationPath: true,
 			Fingerprints: []profile.Fingerprint{
 				{
-					Type:      profile.FingerprintTypePathID,
+					Type:      profile.FingerprintTypeTagID,
+					Key:       tag.Key,
 					Operation: profile.FingerprintOperationEqualsID,
 					Value:     tag.Value, // Value of appImagePathTagKey.
 				},
@@ -85,5 +138,49 @@ func (h *AppImageHandler) CreateProfile(p *process.Process) *profile.Profile {
 		})
 	}
 
+	if tag, ok := p.GetTag(appImageMountIDTagKey); ok {
+		return profile.New(&profile.Profile{
+			Source:              profile.SourceLocal,
+			Name:                osdetail.GenerateBinaryNameFromPath(p.Path),
+			PresentationPath:    p.Path,
+			UsePresentationPath: true,
+			Fingerprints: []profile.Fingerprint{
+				{
+					Type:      profile.FingerprintTypeTagID,
+					Key:       tag.Key,
+					Operation: profile.FingerprintOperationEqualsID,
+					Value:     tag.Value, // Value of appImageMountIDTagKey.
+				},
+			},
+		})
+	}
+
 	return nil
 }
+
+func getAppImageMountName(mountPoint string) (mountName string, err error) {
+	// Get mounts.
+	data, err := os.ReadFile("/proc/mounts")
+	if err != nil {
+		return "", err
+	}
+
+	scanner := bufio.NewScanner(bytes.NewReader(data))
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) >= 2 {
+			switch {
+			case fields[1] != mountPoint:
+			case !strings.HasSuffix(strings.ToLower(fields[0]), ".appimage"):
+			default:
+				// Found AppImage mount!
+				return fields[0], nil
+			}
+		}
+	}
+	if scanner.Err() != nil {
+		return "", scanner.Err()
+	}
+
+	return "", nil
+}