diff options
| author | Ian Lewis <ianlewis@google.com> | 2019-11-26 18:19:47 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-11-26 18:21:09 -0800 |
| commit | 20279c305ece6a458006999c8dafc5672ca92803 (patch) | |
| tree | 086e072c05f1bc0f6f1b972774fad452b7bb6c35 /pkg/sentry/fs/proc | |
| parent | 4a620c436dabbb0d5036e137bfdd44b945e3cff0 (diff) | |
Allow open(O_TRUNC) and (f)truncate for proc files.
This allows writable proc and devices files to be opened with O_CREAT|O_TRUNC.
This is encountered most frequently when interacting with proc or devices files
via the command line.
e.g. $ echo 8192 1048576 4194304 > /proc/sys/net/ipv4/tcp_rmem
Also adds a test to test the behavior of open(O_TRUNC), truncate, and ftruncate
on named pipes.
Fixes #1116
PiperOrigin-RevId: 282677425
Diffstat (limited to 'pkg/sentry/fs/proc')
| -rw-r--r-- | pkg/sentry/fs/proc/sys_net.go | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go index f3b63dfc2..bd93f83fa 100644 --- a/pkg/sentry/fs/proc/sys_net.go +++ b/pkg/sentry/fs/proc/sys_net.go @@ -64,7 +64,7 @@ var _ fs.InodeOperations = (*tcpMemInode)(nil) func newTCPMemInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack, dir tcpMemDir) *fs.Inode { tm := &tcpMemInode{ - SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC), + SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0644), linux.PROC_SUPER_MAGIC), s: s, dir: dir, } @@ -77,6 +77,11 @@ func newTCPMemInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack, dir return fs.NewInode(ctx, tm, msrc, sattr) } +// Truncate implements fs.InodeOperations.Truncate. +func (tcpMemInode) Truncate(context.Context, *fs.Inode, int64) error { + return nil +} + // GetFile implements fs.InodeOperations.GetFile. func (m *tcpMemInode) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { flags.Pread = true @@ -168,14 +173,15 @@ func writeSize(dirType tcpMemDir, s inet.Stack, size inet.TCPBufferSize) error { // +stateify savable type tcpSack struct { + fsutil.SimpleFileInode + stack inet.Stack `state:"wait"` enabled *bool - fsutil.SimpleFileInode } func newTCPSackInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode { ts := &tcpSack{ - SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC), + SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0644), linux.PROC_SUPER_MAGIC), stack: s, } sattr := fs.StableAttr{ @@ -187,6 +193,11 @@ func newTCPSackInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *f return fs.NewInode(ctx, ts, msrc, sattr) } +// Truncate implements fs.InodeOperations.Truncate. +func (tcpSack) Truncate(context.Context, *fs.Inode, int64) error { + return nil +} + // GetFile implements fs.InodeOperations.GetFile. func (s *tcpSack) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { flags.Pread = true |