manager: add a special VM type "none"

Type "none" in config says manager to not manage any VMs,
and just manage the corpus (it still server RPCs).
This is useful when something else manages the VMs
and starts fuzzer processes on them.

2 files changed, 20 insertions, 5 deletions

diff --git a/config/config.go b/config/config.go
index dca74edb0..b98b481db 100644
--- a/config/config.go
+++ b/config/config.go
@@ -18,7 +18,8 @@ import (
 )
 
 type Config struct {
-	Http    string
+	Http    string // TCP address to serve HTTP stats page (e.g. "localhost:50000")
+	Rpc     string // TCP address to serve RPC for fuzzer processes (optional, only useful for type "none")
 	Workdir string
 	Vmlinux string
 	Kernel  string // e.g. arch/x86/boot/bzImage
@@ -97,8 +98,20 @@ func parse(data []byte) (*Config, map[int]bool, []*regexp.Regexp, error) {
 	if cfg.Type == "" {
 		return nil, nil, nil, fmt.Errorf("config param type is empty")
 	}
-	if cfg.Count <= 0 || cfg.Count > 1000 {
-		return nil, nil, nil, fmt.Errorf("invalid config param count: %v, want (1, 1000]", cfg.Count)
+	if cfg.Type == "none" {
+		if cfg.Count != 0 {
+			return nil, nil, nil, fmt.Errorf("invalid config param count: %v, type \"none\" does not support param count", cfg.Count)
+		}
+		if cfg.Rpc == "" {
+			return nil, nil, nil, fmt.Errorf("config param rpc is empty (required for type \"none\")")
+		}
+	} else {
+		if cfg.Count <= 0 || cfg.Count > 1000 {
+			return nil, nil, nil, fmt.Errorf("invalid config param count: %v, want (1, 1000]", cfg.Count)
+		}
+		if cfg.Rpc == "" {
+			cfg.Rpc = "localhost:0"
+		}
 	}
 	if cfg.Procs <= 0 {
 		cfg.Procs = 1
@@ -235,6 +248,7 @@ func checkUnknownFields(data []byte) (string, error) {
 	// we don't have a better way than to enumerate all known fields.
 	var fields = []string{
 		"Http",
+		"Rpc",
 		"Workdir",
 		"Vmlinux",
 		"Kernel",
diff --git a/syz-manager/manager.go b/syz-manager/manager.go
index 2005ed7b7..0c80de938 100644
--- a/syz-manager/manager.go
+++ b/syz-manager/manager.go
@@ -141,7 +141,7 @@ func RunManager(cfg *config.Config, syscalls map[int]bool, suppressions []*regex
 	mgr.initHttp()
 
 	// Create RPC server for fuzzers.
-	ln, err := net.Listen("tcp", "localhost:0")
+	ln, err := net.Listen("tcp", cfg.Rpc)
 	if err != nil {
 		fatalf("failed to listen on localhost:0: %v", err)
 	}
@@ -162,7 +162,7 @@ func RunManager(cfg *config.Config, syscalls map[int]bool, suppressions []*regex
 
 	var shutdown uint32
 	var wg sync.WaitGroup
-	wg.Add(cfg.Count)
+	wg.Add(cfg.Count + 1)
 	for i := 0; i < cfg.Count; i++ {
 		first := i == 0
 		go func() {
@@ -201,6 +201,7 @@ func RunManager(cfg *config.Config, syscalls map[int]bool, suppressions []*regex
 		c := make(chan os.Signal, 2)
 		signal.Notify(c, syscall.SIGINT)
 		<-c
+		wg.Done()
 		atomic.StoreUint32(&mgr.shutdown, 1)
 		*flagV = -1 // VMs will fail
 		logf(-1, "shutting down...")