From 5dc7e44aa2cb6527b0e2f4e7108c8cbd7c2a72c1 Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher
Date: Sun, 11 Oct 2015 17:14:18 +0200
Subject: Move main files to top level dir

This is in preparation of getting rid of the shell wrapper
---
 sendsig.go | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 sendsig.go

(limited to 'sendsig.go')

diff --git a/sendsig.go b/sendsig.go
new file mode 100644
index 0000000..d0e1cbb
--- /dev/null
+++ b/sendsig.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"syscall"
+)
+
+// cmdline looks like this: /bin/bash \0 /path/to/gocryptfs \0 --zerokey \0 ...
+const (
+	WRAPPER_PREFIX   = "/bin/bash\000"
+	WRAPPER_CONTAINS = "gocryptfs\000"
+)
+
+// Send USR1 to the "gocryptfs" wrapper shell script. This notifies it that the
+// mounting has completed sucessfully.
+//
+// Checks /proc/$PPID/cmdline to make sure we do not kill an unrelated process.
+func sendSig() {
+	ppid := os.Getppid()
+	fn := fmt.Sprintf("/proc/%d/cmdline", ppid)
+	cmdline, err := ioutil.ReadFile(fn)
+	if err != nil {
+		fmt.Printf("sendSig: ReadFile: %v\n", err)
+		return
+	}
+	if bytes.HasPrefix(cmdline, []byte(WRAPPER_PREFIX)) && bytes.Contains(cmdline, []byte(WRAPPER_CONTAINS)) {
+		p, err := os.FindProcess(ppid)
+		if err != nil {
+			fmt.Printf("sendSig: FindProcess: %v\n", err)
+			return
+		}
+		err = p.Signal(syscall.SIGUSR1)
+		if err != nil {
+			fmt.Printf("sendSig: Signal: %v\n", err)
+		}
+	} else {
+		fmt.Printf("Not running under the gocryptfs wrapper - will not daemonize\n")
+	}
+}
-- 
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