// Copyright 2018 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package proc import ( "io" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/socket/rpcinet" "gvisor.dev/gvisor/pkg/sentry/usermem" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/waiter" ) // rpcInetInode implements fs.InodeOperations. type rpcInetInode struct { fsutil.SimpleFileInode // filepath is the full path of this rpcInetInode. filepath string k *kernel.Kernel } func newRPCInetInode(ctx context.Context, msrc *fs.MountSource, filepath string, mode linux.FileMode) *fs.Inode { f := &rpcInetInode{ SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(mode), linux.PROC_SUPER_MAGIC), filepath: filepath, k: kernel.KernelFromContext(ctx), } return newProcInode(ctx, f, msrc, fs.SpecialFile, nil) } // GetFile implements fs.InodeOperations.GetFile. func (i *rpcInetInode) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { flags.Pread = true flags.Pwrite = true fops := &rpcInetFile{ inode: i, } return fs.NewFile(ctx, dirent, flags, fops), nil } // rpcInetFile implements fs.FileOperations as RPCs. type rpcInetFile struct { fsutil.FileGenericSeek `state:"nosave"` fsutil.FileNoIoctl `state:"nosave"` fsutil.FileNoMMap `state:"nosave"` fsutil.FileNoSplice `state:"nosave"` fsutil.FileNoopFlush `state:"nosave"` fsutil.FileNoopFsync `state:"nosave"` fsutil.FileNoopRelease `state:"nosave"` fsutil.FileNotDirReaddir `state:"nosave"` fsutil.FileUseInodeUnstableAttr `state:"nosave"` waiter.AlwaysReady `state:"nosave"` inode *rpcInetInode } // Read implements fs.FileOperations.Read. // // This method can panic if an rpcInetInode was created without an rpcinet // stack. func (f *rpcInetFile) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) { if offset < 0 { return 0, syserror.EINVAL } s, ok := f.inode.k.NetworkStack().(*rpcinet.Stack) if !ok { panic("Network stack is not a rpcinet.") } contents, se := s.RPCReadFile(f.inode.filepath) if se != nil || offset >= int64(len(contents)) { return 0, io.EOF } n, err := dst.CopyOut(ctx, contents[offset:]) return int64(n), err } // Write implements fs.FileOperations.Write. // // This method can panic if an rpcInetInode was created without an rpcInet // stack. func (f *rpcInetFile) Write(ctx context.Context, file *fs.File, src usermem.IOSequence, offset int64) (int64, error) { s, ok := f.inode.k.NetworkStack().(*rpcinet.Stack) if !ok { panic("Network stack is not a rpcinet.") } if src.NumBytes() == 0 { return 0, nil } b := make([]byte, src.NumBytes(), src.NumBytes()) n, err := src.CopyIn(ctx, b) if err != nil { return int64(n), err } written, se := s.RPCWriteFile(f.inode.filepath, b) return int64(written), se.ToError() } // newRPCInetProcNet will build an inode for /proc/net. func newRPCInetProcNet(ctx context.Context, msrc *fs.MountSource) *fs.Inode { contents := map[string]*fs.Inode{ "arp": newRPCInetInode(ctx, msrc, "/proc/net/arp", 0444), "dev": newRPCInetInode(ctx, msrc, "/proc/net/dev", 0444), "if_inet6": newRPCInetInode(ctx, msrc, "/proc/net/if_inet6", 0444), "ipv6_route": newRPCInetInode(ctx, msrc, "/proc/net/ipv6_route", 0444), "netlink": newRPCInetInode(ctx, msrc, "/proc/net/netlink", 0444), "netstat": newRPCInetInode(ctx, msrc, "/proc/net/netstat", 0444), "packet": newRPCInetInode(ctx, msrc, "/proc/net/packet", 0444), "protocols": newRPCInetInode(ctx, msrc, "/proc/net/protocols", 0444), "psched": newRPCInetInode(ctx, msrc, "/proc/net/psched", 0444), "ptype": newRPCInetInode(ctx, msrc, "/proc/net/ptype", 0444), "route": newRPCInetInode(ctx, msrc, "/proc/net/route", 0444), "tcp": newRPCInetInode(ctx, msrc, "/proc/net/tcp", 0444), "tcp6": newRPCInetInode(ctx, msrc, "/proc/net/tcp6", 0444), "udp": newRPCInetInode(ctx, msrc, "/proc/net/udp", 0444), "udp6": newRPCInetInode(ctx, msrc, "/proc/net/udp6", 0444), } d := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil) } // newRPCInetProcSysNet will build an inode for /proc/sys/net. func newRPCInetProcSysNet(ctx context.Context, msrc *fs.MountSource) *fs.Inode { contents := map[string]*fs.Inode{ "ipv4": newRPCInetSysNetIPv4Dir(ctx, msrc), "core": newRPCInetSysNetCore(ctx, msrc), } d := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil) } // newRPCInetSysNetCore builds the /proc/sys/net/core directory. func newRPCInetSysNetCore(ctx context.Context, msrc *fs.MountSource) *fs.Inode { contents := map[string]*fs.Inode{ "default_qdisc": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/default_qdisc", 0444), "message_burst": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/message_burst", 0444), "message_cost": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/message_cost", 0444), "optmem_max": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/optmem_max", 0444), "rmem_default": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/rmem_default", 0444), "rmem_max": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/rmem_max", 0444), "somaxconn": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/somaxconn", 0444), "wmem_default": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/wmem_default", 0444), "wmem_max": newRPCInetInode(ctx, msrc, "/proc/sys/net/core/wmem_max", 0444), } d := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil) } // newRPCInetSysNetIPv4Dir builds the /proc/sys/net/ipv4 directory. func newRPCInetSysNetIPv4Dir(ctx context.Context, msrc *fs.MountSource) *fs.Inode { contents := map[string]*fs.Inode{ "ip_local_port_range": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/ip_local_port_range", 0444), "ip_local_reserved_ports": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/ip_local_reserved_ports", 0444), "ipfrag_time": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/ipfrag_time", 0444), "ip_nonlocal_bind": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/ip_nonlocal_bind", 0444), "ip_no_pmtu_disc": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/ip_no_pmtu_disc", 0444), "tcp_allowed_congestion_control": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_allowed_congestion_control", 0444), "tcp_available_congestion_control": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_available_congestion_control", 0444), "tcp_base_mss": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_base_mss", 0444), "tcp_congestion_control": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_congestion_control", 0644), "tcp_dsack": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_dsack", 0644), "tcp_early_retrans": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_early_retrans", 0644), "tcp_fack": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_fack", 0644), "tcp_fastopen": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_fastopen", 0644), "tcp_fastopen_key": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_fastopen_key", 0444), "tcp_fin_timeout": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_fin_timeout", 0644), "tcp_invalid_ratelimit": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_invalid_ratelimit", 0444), "tcp_keepalive_intvl": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_keepalive_intvl", 0644), "tcp_keepalive_probes": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_keepalive_probes", 0644), "tcp_keepalive_time": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_keepalive_time", 0644), "tcp_mem": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_mem", 0444), "tcp_mtu_probing": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_mtu_probing", 0644), "tcp_no_metrics_save": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_no_metrics_save", 0444), "tcp_probe_interval": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_probe_interval", 0444), "tcp_probe_threshold": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_probe_threshold", 0444), "tcp_retries1": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_retries1", 0644), "tcp_retries2": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_retries2", 0644), "tcp_rfc1337": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_rfc1337", 0444), "tcp_rmem": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_rmem", 0444), "tcp_sack": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_sack", 0644), "tcp_slow_start_after_idle": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_slow_start_after_idle", 0644), "tcp_synack_retries": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_synack_retries", 0644), "tcp_syn_retries": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_syn_retries", 0644), "tcp_timestamps": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_timestamps", 0644), "tcp_wmem": newRPCInetInode(ctx, msrc, "/proc/sys/net/ipv4/tcp_wmem", 0444), } d := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555)) return newProcInode(ctx, d, msrc, fs.SpecialDirectory, nil) }