Implement proper daemonization

The shell wrapper sends gocryptfs into the background and waits for SIGUSR1
This commit is contained in:
Jakob Unterwurzacher 2015-10-06 00:29:08 +02:00
parent 552c32c5e9
commit 022a6968ae
5 changed files with 77 additions and 26 deletions

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@ -3,6 +3,4 @@
set -eu set -eu
cd gocryptfs_main cd gocryptfs_main
echo -n "Compiling... "
go build go build
echo "done."

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@ -9,10 +9,11 @@ import (
) )
const ( const (
DEFAULT_PLAINBS = 4096
KEY_LEN = 16 KEY_LEN = 16
NONCE_LEN = 12 NONCE_LEN = 12
AUTH_TAG_LEN = 16 AUTH_TAG_LEN = 16
DEFAULT_PLAINBS = 4096 FILEID_LEN = 16
) )
type CryptFS struct { type CryptFS struct {

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@ -1,9 +1,13 @@
#!/bin/bash #!/bin/bash
# Simple wrapper that runs the gocryptfs process in the background # Shell wrapper that runs the gocryptfs process in the background
# and exits on SIGUSR1
set -eu set -eu
trap "exit 0" SIGUSR1
shopt -u huponexit
dir=$(dirname "$0") dir=$(dirname "$0")
main="$dir/gocryptfs_main/gocryptfs_main" main="$dir/gocryptfs_main/gocryptfs_main"
@ -12,11 +16,8 @@ if [ ! -x $main ]; then
exit 1 exit 1
fi fi
# This needs user input and cannot run in the background # A backgrounded process gets /dev/null as stdin per default.
if [[ $* == *--init* ]]; then # Explicitly set stdin to the current stdin so we can ask the user for input.
"$main" $* "$main" $* < /proc/self/fd/0 & wait
else # The "& wait" is neccessary because bash only processes signals when
"$main" $* & # executing internal commands
sleep 0.1
disown
fi

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@ -128,11 +128,20 @@ func main() {
fmt.Println(err) fmt.Println(err)
os.Exit(ERREXIT_LOADCONF) os.Exit(ERREXIT_LOADCONF)
} }
fmt.Printf("Success\n") fmt.Printf("done.\n")
}
srv := pathfsFrontend(key, cipherdir, mountpoint, fusedebug)
fmt.Printf("Mounted.\n")
if zerokey == false {
printMasterKey(key) printMasterKey(key)
} }
pathfsFrontend(key, cipherdir, mountpoint, fusedebug) // Send notification to our parent
sendSig()
// Jump into server loop
srv.Serve()
} }
// printMasterKey - remind the user that he should store the master key in // printMasterKey - remind the user that he should store the master key in
@ -143,12 +152,13 @@ func printMasterKey(key []byte) {
h = h[0:8] + "-" + h[8:16] + "-" + h[16:24] + "-" + h[24:32] h = h[0:8] + "-" + h[8:16] + "-" + h[16:24] + "-" + h[24:32]
fmt.Printf(` fmt.Printf(`
WARNING: ATTENTION:
If the gocryptfs config file becomes corrupted or you ever
forget your password, there is only one hope for recovery:
The master key. Print it to a piece of paper and store it in a drawer.
Master key: %s Your master key is: %s
If the gocryptfs.conf file becomes corrupted or you ever forget your password,
there is only one hope for recovery: The master key. Print it to a piece of
paper and store it in a drawer.
`, h) `, h)
} }
@ -171,7 +181,7 @@ func readPassword() string {
fd := int(os.Stdin.Fd()) fd := int(os.Stdin.Fd())
p, err := terminal.ReadPassword(fd) p, err := terminal.ReadPassword(fd)
if err != nil { if err != nil {
fmt.Printf("Error: Could not read password: %s\n") fmt.Printf("Error: Could not read password: %v\n", err)
os.Exit(ERREXIT_PASSWORD) os.Exit(ERREXIT_PASSWORD)
} }
return string(p) return string(p)
@ -189,7 +199,7 @@ func dirEmpty(dir string) bool {
return false return false
} }
func pathfsFrontend(key []byte, cipherdir string, mountpoint string, debug bool) { func pathfsFrontend(key []byte, cipherdir string, mountpoint string, debug bool) *fuse.Server {
finalFs := pathfs_frontend.NewFS(key, cipherdir, USE_OPENSSL) finalFs := pathfs_frontend.NewFS(key, cipherdir, USE_OPENSSL)
pathFsOpts := &pathfs.PathNodeFsOptions{ClientInodes: true} pathFsOpts := &pathfs.PathNodeFsOptions{ClientInodes: true}
@ -210,13 +220,12 @@ func pathfsFrontend(key []byte, cipherdir string, mountpoint string, debug bool)
// Second column, "Type", will be shown as "fuse." + Name // Second column, "Type", will be shown as "fuse." + Name
mOpts.Name = "gocryptfs" mOpts.Name = "gocryptfs"
state, err := fuse.NewServer(conn.RawFS(), mountpoint, &mOpts) srv, err := fuse.NewServer(conn.RawFS(), mountpoint, &mOpts)
if err != nil { if err != nil {
fmt.Printf("Mount fail: %v\n", err) fmt.Printf("Mount failed: %v", err)
os.Exit(1) os.Exit(1)
} }
state.SetDebug(debug) srv.SetDebug(debug)
fmt.Println("Mounted.") return srv
state.Serve()
} }

42
gocryptfs_main/sendsig.go Normal file
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@ -0,0 +1,42 @@
package main
import (
"syscall"
"bytes"
"fmt"
"os"
"io/ioutil"
)
// 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")
}
}