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-rw-r--r--internal/fusefrontend_reverse/node.go19
-rw-r--r--internal/fusefrontend_reverse/node_helpers.go26
-rw-r--r--internal/fusefrontend_reverse/root_node.go24
-rw-r--r--internal/fusefrontend_reverse/virtualnode.go11
-rw-r--r--internal/generation_num/generation_num.go11
-rw-r--r--internal/inomap/inomap.go41
-rw-r--r--internal/inomap/inomap_test.go13
-rw-r--r--internal/speed/speed.go6
-rw-r--r--internal/stupidgcm/cipher_suites.go28
-rw-r--r--internal/stupidgcm/prefer.go14
-rw-r--r--internal/syscallcompat/sys_common.go5
11 files changed, 143 insertions, 55 deletions
diff --git a/internal/fusefrontend_reverse/node.go b/internal/fusefrontend_reverse/node.go
index 170410f..22ad975 100644
--- a/internal/fusefrontend_reverse/node.go
+++ b/internal/fusefrontend_reverse/node.go
@@ -68,6 +68,25 @@ func (n *Node) Lookup(ctx context.Context, cName string, out *fuse.EntryOut) (ch
if t == typeReal {
n.translateSize(d.dirfd, cName, d.pName, &out.Attr)
}
+
+ // Usually we always create a new Node ID by always incrementing the generation
+ // number.
+ //
+ // If we already have a child node that matches what we found on disk*
+ // (as reflected in `ch`), return it here.
+ //
+ // This keeps the Node ID for each directory entry stable
+ // (until forgotten), preventing extra FORGETs from the kernel.
+ //
+ // *We compare `cName`, `Ino`, `Mode` (but not `Gen`!)
+ old := n.Inode.GetChild(cName)
+ if old != nil &&
+ old.StableAttr().Ino == ch.StableAttr().Ino &&
+ // `Mode` has already been masked with syscall.S_IFMT by n.newChild()
+ old.StableAttr().Mode == ch.StableAttr().Mode {
+ return old, 0
+ }
+
return ch, 0
}
diff --git a/internal/fusefrontend_reverse/node_helpers.go b/internal/fusefrontend_reverse/node_helpers.go
index 96c3c2d..6bba097 100644
--- a/internal/fusefrontend_reverse/node_helpers.go
+++ b/internal/fusefrontend_reverse/node_helpers.go
@@ -91,18 +91,17 @@ func (n *Node) prepareAtSyscall(child string) (d *dirfdPlus, errno syscall.Errno
// newChild attaches a new child inode to n.
// The passed-in `st` will be modified to get a unique inode number.
+//
+// This function is not used for virtual files. See lookupLongnameName(),
+// lookupDiriv() instead.
func (n *Node) newChild(ctx context.Context, st *syscall.Stat_t, out *fuse.EntryOut) *fs.Inode {
- isOtherFilesystem := (uint64(st.Dev) != n.rootNode().rootDev)
- // Get unique inode number
rn := n.rootNode()
+ isOtherFilesystem := (uint64(st.Dev) != rn.rootDev)
+ // Get unique inode number
rn.inoMap.TranslateStat(st)
out.Attr.FromStat(st)
// Create child node
- id := fs.StableAttr{
- Mode: uint32(st.Mode),
- Gen: 1,
- Ino: st.Ino,
- }
+ id := rn.uniqueStableAttr(uint32(st.Mode), st.Ino)
node := &Node{
isOtherFilesystem: isOtherFilesystem,
}
@@ -153,7 +152,7 @@ func (n *Node) lookupLongnameName(ctx context.Context, nameFile string, out *fus
}
out.Attr = vf.attr
// Create child node
- id := fs.StableAttr{Mode: uint32(vf.attr.Mode), Gen: 1, Ino: vf.attr.Ino}
+ id := rn.uniqueStableAttr(uint32(vf.attr.Mode), vf.attr.Ino)
ch = n.NewInode(ctx, vf, id)
return
@@ -161,7 +160,8 @@ func (n *Node) lookupLongnameName(ctx context.Context, nameFile string, out *fus
// lookupDiriv returns a new Inode for a gocryptfs.diriv file inside `n`.
func (n *Node) lookupDiriv(ctx context.Context, out *fuse.EntryOut) (ch *fs.Inode, errno syscall.Errno) {
- if rn := n.rootNode(); rn.args.DeterministicNames {
+ rn := n.rootNode()
+ if rn.args.DeterministicNames {
log.Panic("BUG: lookupDiriv called but DeterministicNames is set")
}
@@ -183,7 +183,7 @@ func (n *Node) lookupDiriv(ctx context.Context, out *fuse.EntryOut) (ch *fs.Inod
}
out.Attr = vf.attr
// Create child node
- id := fs.StableAttr{Mode: uint32(vf.attr.Mode), Gen: 1, Ino: vf.attr.Ino}
+ id := rn.uniqueStableAttr(uint32(vf.attr.Mode), vf.attr.Ino)
ch = n.NewInode(ctx, vf, id)
return
}
@@ -202,11 +202,7 @@ func (n *Node) lookupConf(ctx context.Context, out *fuse.EntryOut) (ch *fs.Inode
rn.inoMap.TranslateStat(&st)
out.Attr.FromStat(&st)
// Create child node
- id := fs.StableAttr{
- Mode: uint32(st.Mode),
- Gen: 1,
- Ino: st.Ino,
- }
+ id := rn.uniqueStableAttr(uint32(st.Mode), st.Ino)
node := &VirtualConfNode{path: p}
ch = n.NewInode(ctx, node, id)
return
diff --git a/internal/fusefrontend_reverse/root_node.go b/internal/fusefrontend_reverse/root_node.go
index 8a2afd9..1a68ffd 100644
--- a/internal/fusefrontend_reverse/root_node.go
+++ b/internal/fusefrontend_reverse/root_node.go
@@ -5,6 +5,7 @@ import (
"os"
"path/filepath"
"strings"
+ "sync/atomic"
"syscall"
"github.com/rfjakob/gocryptfs/v2/internal/exitcodes"
@@ -45,6 +46,13 @@ type RootNode struct {
// If a file name length is shorter than shortNameMax, there is no need to
// hash it.
shortNameMax int
+ // gen is the node generation number. Normally, it is always set to 1,
+ // but reverse mode, like -sharestorage, uses an incrementing counter for new nodes.
+ // This makes each directory entry unique (even hard links),
+ // makes go-fuse hand out separate FUSE Node IDs for each, and prevents
+ // bizarre problems when inode numbers are reused behind our back,
+ // like this one: https://github.com/rfjakob/gocryptfs/issues/802
+ gen uint64
}
// NewRootNode returns an encrypted FUSE overlay filesystem.
@@ -149,3 +157,19 @@ func (rn *RootNode) excludeDirEntries(d *dirfdPlus, entries []fuse.DirEntry) (fi
}
return filtered
}
+
+// uniqueStableAttr returns a fs.StableAttr struct with a unique generation number,
+// preventing files to appear hard-linked, even when they have the same inode number.
+//
+// This is good because inode numbers can be reused behind our back, which could make
+// unrelated files appear hard-linked.
+// Example: https://github.com/rfjakob/gocryptfs/issues/802
+func (rn *RootNode) uniqueStableAttr(mode uint32, ino uint64) fs.StableAttr {
+ return fs.StableAttr{
+ Mode: mode,
+ Ino: ino,
+ // Make each directory entry a unique node by using a unique generation
+ // value. Also see the comment at RootNode.gen for details.
+ Gen: atomic.AddUint64(&rn.gen, 1),
+ }
+}
diff --git a/internal/fusefrontend_reverse/virtualnode.go b/internal/fusefrontend_reverse/virtualnode.go
index 688f536..922cfa7 100644
--- a/internal/fusefrontend_reverse/virtualnode.go
+++ b/internal/fusefrontend_reverse/virtualnode.go
@@ -86,8 +86,15 @@ func (n *Node) newVirtualMemNode(content []byte, parentStat *syscall.Stat_t, ino
// Adjust inode number and size
rn := n.rootNode()
st := parentStat
- q := inomap.NewQIno(uint64(st.Dev), inoTag, uint64(st.Ino))
- st.Ino = rn.inoMap.Translate(q)
+ if inoTag == inoTagNameFile {
+ // No stable mapping for gocryptfs.longname.*.name files, instead use an
+ // incrementing counter. We don't want two of those files to ever have the
+ // same inode number, even for hard-linked files.
+ st.Ino = rn.inoMap.NextSpillIno()
+ } else {
+ q := inomap.NewQIno(uint64(st.Dev), inoTag, uint64(st.Ino))
+ st.Ino = rn.inoMap.Translate(q)
+ }
st.Size = int64(len(content))
st.Mode = virtualFileMode
st.Nlink = 1
diff --git a/internal/generation_num/generation_num.go b/internal/generation_num/generation_num.go
deleted file mode 100644
index 298db14..0000000
--- a/internal/generation_num/generation_num.go
+++ /dev/null
@@ -1,11 +0,0 @@
-package generation_num
-
-import (
- "sync/atomic"
-)
-
-var gen uint64
-
-func Next() uint64 {
- return atomic.AddUint64(&gen, 1)
-}
diff --git a/internal/inomap/inomap.go b/internal/inomap/inomap.go
index 0f7ade3..b4dbf27 100644
--- a/internal/inomap/inomap.go
+++ b/internal/inomap/inomap.go
@@ -3,8 +3,8 @@
//
// Format of the returned inode numbers:
//
-// [spill bit = 0][15 bit namespace id][48 bit passthru inode number]
-// [spill bit = 1][63 bit spill inode number ]
+// [spill bit = 0][15 bit namespace id][48 bit passthru inode number] = 64 bit translated inode number
+// [spill bit = 1][63 bit counter ] = 64 bit spill inode number
//
// Each (Dev, Tag) tuple gets a namespace id assigned. The original inode
// number is then passed through in the lower 48 bits.
@@ -16,7 +16,9 @@ package inomap
import (
"log"
+ "math"
"sync"
+ "sync/atomic"
"syscall"
"github.com/rfjakob/gocryptfs/v2/internal/tlog"
@@ -27,10 +29,8 @@ const (
maxNamespaceId = 1<<15 - 1
// max value of 48 bit passthru inode number
maxPassthruIno = 1<<48 - 1
- // max value of 63 bit spill inode number
- maxSpillIno = 1<<63 - 1
- // bit 63 is used as the spill bit
- spillBit = 1 << 63
+ // the spill inode number space starts at 0b10000...0.
+ spillSpaceStart = 1 << 63
)
// InoMap stores the maps using for inode number translation.
@@ -57,7 +57,7 @@ func New(rootDev uint64) *InoMap {
namespaceMap: make(map[namespaceData]uint16),
namespaceNext: 0,
spillMap: make(map[QIno]uint64),
- spillNext: 0,
+ spillNext: spillSpaceStart,
}
if rootDev > 0 {
// Reserve namespace 0 for rootDev
@@ -69,23 +69,32 @@ func New(rootDev uint64) *InoMap {
var spillWarn sync.Once
+// NextSpillIno returns a fresh inode number from the spill pool without adding it to
+// spillMap.
+// Reverse mode NextSpillIno() for gocryptfs.longname.*.name files where a stable
+// mapping is not needed.
+func (m *InoMap) NextSpillIno() (out uint64) {
+ if m.spillNext == math.MaxUint64 {
+ log.Panicf("spillMap overflow: spillNext = 0x%x", m.spillNext)
+ }
+ return atomic.AddUint64(&m.spillNext, 1) - 1
+}
+
func (m *InoMap) spill(in QIno) (out uint64) {
- spillWarn.Do(func() { tlog.Warn.Printf("InoMap: opening spillMap for %v", in) })
+ spillWarn.Do(func() { tlog.Warn.Printf("InoMap: opening spillMap for %#v", in) })
out, found := m.spillMap[in]
if found {
- return out | spillBit
- }
- if m.spillNext >= maxSpillIno {
- log.Panicf("spillMap overflow: spillNext = 0x%x", m.spillNext)
+ return out
}
- out = m.spillNext
- m.spillNext++
+
+ out = m.NextSpillIno()
m.spillMap[in] = out
- return out | spillBit
+
+ return out
}
-// Translate maps the passed-in (device, inode) pair to a unique inode number.
+// Translate maps the passed-in (device, tag, inode) tuple to a unique inode number.
func (m *InoMap) Translate(in QIno) (out uint64) {
m.Lock()
defer m.Unlock()
diff --git a/internal/inomap/inomap_test.go b/internal/inomap/inomap_test.go
index 9ec2932..ce5b880 100644
--- a/internal/inomap/inomap_test.go
+++ b/internal/inomap/inomap_test.go
@@ -5,6 +5,11 @@ import (
"testing"
)
+const (
+ // bit 63 is used as the spill bit
+ spillBit = 1 << 63
+)
+
func TestTranslate(t *testing.T) {
m := New(0)
q := QIno{Ino: 1}
@@ -102,6 +107,9 @@ func TestSpill(t *testing.T) {
if out1&spillBit == 0 {
t.Error("spill bit not set")
}
+ if out1 != spillSpaceStart {
+ t.Errorf("unexpected first spill inode number %d", out1)
+ }
out2 := m.Translate(q)
if out2&spillBit == 0 {
t.Error("spill bit not set")
@@ -109,6 +117,11 @@ func TestSpill(t *testing.T) {
if out1 != out2 {
t.Errorf("unstable mapping: %d vs %d", out1, out2)
}
+ q.Ino = maxPassthruIno + 2
+ out3 := m.Translate(q)
+ if out3 != out1+1 {
+ t.Errorf("unexpected 2nd spill inode number %d", out1)
+ }
}
// TestUniqueness checks that unique (Dev, Flags, Ino) tuples get unique inode
diff --git a/internal/speed/speed.go b/internal/speed/speed.go
index a361cf5..d6fa12e 100644
--- a/internal/speed/speed.go
+++ b/internal/speed/speed.go
@@ -31,9 +31,9 @@ func Run() {
if cpu == "" {
cpu = "unknown"
}
- aes := "; no AES acceleration"
- if stupidgcm.CpuHasAES() {
- aes = "; with AES acceleration"
+ aes := "; no AES-GCM acceleration"
+ if stupidgcm.HasAESGCMHardwareSupport() {
+ aes = "; with AES-GCM acceleration"
}
fmt.Printf("cpu: %s%s\n", cpu, aes)
diff --git a/internal/stupidgcm/cipher_suites.go b/internal/stupidgcm/cipher_suites.go
new file mode 100644
index 0000000..fd032fd
--- /dev/null
+++ b/internal/stupidgcm/cipher_suites.go
@@ -0,0 +1,28 @@
+package stupidgcm
+
+import (
+ "runtime"
+
+ "golang.org/x/sys/cpu"
+)
+
+// ********
+// Carbon-copied from Go Stdlib
+// https://github.com/golang/go/blob/45967bb18e04fa6dc62c2786c87ce120443c64f6/src/crypto/tls/cipher_suites.go#L367
+// ********
+
+var (
+ hasGCMAsmAMD64 = cpu.X86.HasAES && cpu.X86.HasPCLMULQDQ
+ hasGCMAsmARM64 = cpu.ARM64.HasAES && cpu.ARM64.HasPMULL
+ // Keep in sync with crypto/aes/cipher_s390x.go.
+ hasGCMAsmS390X = cpu.S390X.HasAES && cpu.S390X.HasAESCBC && cpu.S390X.HasAESCTR &&
+ (cpu.S390X.HasGHASH || cpu.S390X.HasAESGCM)
+
+ hasAESGCMHardwareSupport = runtime.GOARCH == "amd64" && hasGCMAsmAMD64 ||
+ runtime.GOARCH == "arm64" && hasGCMAsmARM64 ||
+ runtime.GOARCH == "s390x" && hasGCMAsmS390X
+)
+
+// ********
+// End carbon-copy
+// ********
diff --git a/internal/stupidgcm/prefer.go b/internal/stupidgcm/prefer.go
index e3f52d4..6a8cf77 100644
--- a/internal/stupidgcm/prefer.go
+++ b/internal/stupidgcm/prefer.go
@@ -2,8 +2,6 @@ package stupidgcm
import (
"runtime"
-
- "golang.org/x/sys/cpu"
)
// PreferOpenSSLAES256GCM tells us if OpenSSL AES-256-GCM is faster than Go stdlib
@@ -22,7 +20,7 @@ func PreferOpenSSLAES256GCM() bool {
return false
}
// If the CPU has AES acceleration, Go stdlib is faster
- if CpuHasAES() {
+ if HasAESGCMHardwareSupport() {
return false
}
// Otherwise OpenSSL is probably faster
@@ -44,13 +42,13 @@ func PreferOpenSSLXchacha20poly1305() bool {
return true
}
-// CpuHasAES tells you if the CPU we are running has AES acceleration that is
-// usable by the Go crypto library.
-func CpuHasAES() bool {
- // Safe to call on other architectures - will just read false.
- if cpu.X86.HasAES || cpu.ARM64.HasAES {
+// HasAESGCMHardwareSupport tells you if the CPU we are running has AES-GCM
+// acceleration that is usable by the Go crypto library.
+func HasAESGCMHardwareSupport() bool {
+ if hasAESGCMHardwareSupport {
return true
}
+
// On the Apple M1, the CPU has AES acceleration, despite cpu.ARM64.HasAES
// reading false: https://github.com/rfjakob/gocryptfs/issues/556#issuecomment-848079309
if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
diff --git a/internal/syscallcompat/sys_common.go b/internal/syscallcompat/sys_common.go
index 50b8180..1aa6a6e 100644
--- a/internal/syscallcompat/sys_common.go
+++ b/internal/syscallcompat/sys_common.go
@@ -60,6 +60,11 @@ func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
flags |= syscall.O_NOFOLLOW
}
}
+
+ // os/exec expects all fds to have O_CLOEXEC or it will leak fds to subprocesses.
+ // In our case, that would be logger(1), and we did leak fds to it.
+ flags |= syscall.O_CLOEXEC
+
fd, err = retryEINTR2(func() (int, error) {
return unix.Openat(dirfd, path, flags, mode)
})
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-26 15:44:55 +0000