diff options
Diffstat (limited to 'pkg/sentry/fsimpl/proc')
| -rw-r--r-- | pkg/sentry/fsimpl/proc/tasks_sys.go | 78 |
1 files changed, 72 insertions, 6 deletions
diff --git a/pkg/sentry/fsimpl/proc/tasks_sys.go b/pkg/sentry/fsimpl/proc/tasks_sys.go index fd7823daa..fb274b78e 100644 --- a/pkg/sentry/fsimpl/proc/tasks_sys.go +++ b/pkg/sentry/fsimpl/proc/tasks_sys.go @@ -17,6 +17,7 @@ package proc import ( "bytes" "fmt" + "math" "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" @@ -69,17 +70,17 @@ func (fs *filesystem) newSysNetDir(ctx context.Context, root *auth.Credentials, if stack := k.RootNetworkNamespace().Stack(); stack != nil { contents = map[string]kernfs.Inode{ "ipv4": fs.newStaticDir(ctx, root, map[string]kernfs.Inode{ - "tcp_recovery": fs.newInode(ctx, root, 0644, &tcpRecoveryData{stack: stack}), - "tcp_rmem": fs.newInode(ctx, root, 0644, &tcpMemData{stack: stack, dir: tcpRMem}), - "tcp_sack": fs.newInode(ctx, root, 0644, &tcpSackData{stack: stack}), - "tcp_wmem": fs.newInode(ctx, root, 0644, &tcpMemData{stack: stack, dir: tcpWMem}), - "ip_forward": fs.newInode(ctx, root, 0444, &ipForwarding{stack: stack}), + "ip_forward": fs.newInode(ctx, root, 0444, &ipForwarding{stack: stack}), + "ip_local_port_range": fs.newInode(ctx, root, 0644, &portRange{stack: stack}), + "tcp_recovery": fs.newInode(ctx, root, 0644, &tcpRecoveryData{stack: stack}), + "tcp_rmem": fs.newInode(ctx, root, 0644, &tcpMemData{stack: stack, dir: tcpRMem}), + "tcp_sack": fs.newInode(ctx, root, 0644, &tcpSackData{stack: stack}), + "tcp_wmem": fs.newInode(ctx, root, 0644, &tcpMemData{stack: stack, dir: tcpWMem}), // The following files are simple stubs until they are implemented in // netstack, most of these files are configuration related. We use the // value closest to the actual netstack behavior or any empty file, all // of these files will have mode 0444 (read-only for all users). - "ip_local_port_range": fs.newInode(ctx, root, 0444, newStaticFile("16000 65535")), "ip_local_reserved_ports": fs.newInode(ctx, root, 0444, newStaticFile("")), "ipfrag_time": fs.newInode(ctx, root, 0444, newStaticFile("30")), "ip_nonlocal_bind": fs.newInode(ctx, root, 0444, newStaticFile("0")), @@ -421,3 +422,68 @@ func (ipf *ipForwarding) Write(ctx context.Context, src usermem.IOSequence, offs } return n, nil } + +// portRange implements vfs.WritableDynamicBytesSource for +// /proc/sys/net/ipv4/ip_local_port_range. +// +// +stateify savable +type portRange struct { + kernfs.DynamicBytesFile + + stack inet.Stack `state:"wait"` + + // start and end store the port range. We must save/restore this here, + // since a netstack instance is created on restore. + start *uint16 + end *uint16 +} + +var _ vfs.WritableDynamicBytesSource = (*portRange)(nil) + +// Generate implements vfs.DynamicBytesSource.Generate. +func (pr *portRange) Generate(ctx context.Context, buf *bytes.Buffer) error { + if pr.start == nil { + start, end := pr.stack.PortRange() + pr.start = &start + pr.end = &end + } + _, err := fmt.Fprintf(buf, "%d %d\n", *pr.start, *pr.end) + return err +} + +// Write implements vfs.WritableDynamicBytesSource.Write. +func (pr *portRange) Write(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) { + if offset != 0 { + // No need to handle partial writes thus far. + return 0, syserror.EINVAL + } + if src.NumBytes() == 0 { + return 0, nil + } + + // Limit input size so as not to impact performance if input size is + // large. + src = src.TakeFirst(usermem.PageSize - 1) + + ports := make([]int32, 2) + n, err := usermem.CopyInt32StringsInVec(ctx, src.IO, src.Addrs, ports, src.Opts) + if err != nil { + return 0, err + } + + // Port numbers must be uint16s. + if ports[0] < 0 || ports[1] < 0 || ports[0] > math.MaxUint16 || ports[1] > math.MaxUint16 { + return 0, syserror.EINVAL + } + + if err := pr.stack.SetPortRange(uint16(ports[0]), uint16(ports[1])); err != nil { + return 0, err + } + if pr.start == nil { + pr.start = new(uint16) + pr.end = new(uint16) + } + *pr.start = uint16(ports[0]) + *pr.end = uint16(ports[1]) + return n, nil +} |