1 files changed, 154 insertions, 0 deletions
diff --git a/runsc/boot/limits.go b/runsc/boot/limits.go
new file mode 100644
index 000000000..ce62236e5
--- /dev/null
+++ b/runsc/boot/limits.go
@@ -0,0 +1,154 @@
+// 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 boot
+
+import (
+	"fmt"
+	"syscall"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/sentry/limits"
+	"gvisor.dev/gvisor/pkg/sync"
+)
+
+// Mapping from linux resource names to limits.LimitType.
+var fromLinuxResource = map[string]limits.LimitType{
+	"RLIMIT_AS":         limits.AS,
+	"RLIMIT_CORE":       limits.Core,
+	"RLIMIT_CPU":        limits.CPU,
+	"RLIMIT_DATA":       limits.Data,
+	"RLIMIT_FSIZE":      limits.FileSize,
+	"RLIMIT_LOCKS":      limits.Locks,
+	"RLIMIT_MEMLOCK":    limits.MemoryLocked,
+	"RLIMIT_MSGQUEUE":   limits.MessageQueueBytes,
+	"RLIMIT_NICE":       limits.Nice,
+	"RLIMIT_NOFILE":     limits.NumberOfFiles,
+	"RLIMIT_NPROC":      limits.ProcessCount,
+	"RLIMIT_RSS":        limits.Rss,
+	"RLIMIT_RTPRIO":     limits.RealTimePriority,
+	"RLIMIT_RTTIME":     limits.Rttime,
+	"RLIMIT_SIGPENDING": limits.SignalsPending,
+	"RLIMIT_STACK":      limits.Stack,
+}
+
+func findName(lt limits.LimitType) string {
+	for k, v := range fromLinuxResource {
+		if v == lt {
+			return k
+		}
+	}
+	return "unknown"
+}
+
+var defaults defs
+
+type defs struct {
+	mu  sync.Mutex
+	set *limits.LimitSet
+	err error
+}
+
+func (d *defs) get() (*limits.LimitSet, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if d.err != nil {
+		return nil, d.err
+	}
+	if d.set == nil {
+		if err := d.initDefaults(); err != nil {
+			d.err = err
+			return nil, err
+		}
+	}
+	return d.set, nil
+}
+
+func (d *defs) initDefaults() error {
+	ls, err := limits.NewLinuxLimitSet()
+	if err != nil {
+		return err
+	}
+
+	// Set default limits based on what containers get by default, ex:
+	// $ docker run --rm debian prlimit
+	ls.SetUnchecked(limits.AS, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.Core, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.CPU, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.Data, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.FileSize, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.Locks, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.MemoryLocked, limits.Limit{Cur: 65536, Max: 65536})
+	ls.SetUnchecked(limits.MessageQueueBytes, limits.Limit{Cur: 819200, Max: 819200})
+	ls.SetUnchecked(limits.Nice, limits.Limit{Cur: 0, Max: 0})
+	ls.SetUnchecked(limits.NumberOfFiles, limits.Limit{Cur: 1048576, Max: 1048576})
+	ls.SetUnchecked(limits.ProcessCount, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.Rss, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.RealTimePriority, limits.Limit{Cur: 0, Max: 0})
+	ls.SetUnchecked(limits.Rttime, limits.Limit{Cur: limits.Infinity, Max: limits.Infinity})
+	ls.SetUnchecked(limits.SignalsPending, limits.Limit{Cur: 0, Max: 0})
+	ls.SetUnchecked(limits.Stack, limits.Limit{Cur: 8388608, Max: limits.Infinity})
+
+	// Read host limits that directly affect the sandbox and adjust the defaults
+	// based on them.
+	for _, res := range []int{syscall.RLIMIT_FSIZE, syscall.RLIMIT_NOFILE} {
+		var hl syscall.Rlimit
+		if err := syscall.Getrlimit(res, &hl); err != nil {
+			return err
+		}
+
+		lt, ok := limits.FromLinuxResource[res]
+		if !ok {
+			return fmt.Errorf("unknown rlimit type %v", res)
+		}
+		hostLimit := limits.Limit{
+			Cur: limits.FromLinux(hl.Cur),
+			Max: limits.FromLinux(hl.Max),
+		}
+
+		defaultLimit := ls.Get(lt)
+		if hostLimit.Cur != limits.Infinity && hostLimit.Cur < defaultLimit.Cur {
+			log.Warningf("Host limit is lower than recommended, resource: %q, host: %d, recommended: %d", findName(lt), hostLimit.Cur, defaultLimit.Cur)
+		}
+		if hostLimit.Cur != defaultLimit.Cur || hostLimit.Max != defaultLimit.Max {
+			log.Infof("Setting limit from host, resource: %q {soft: %d, hard: %d}", findName(lt), hostLimit.Cur, hostLimit.Max)
+			ls.SetUnchecked(lt, hostLimit)
+		}
+	}
+
+	d.set = ls
+	return nil
+}
+
+func createLimitSet(spec *specs.Spec) (*limits.LimitSet, error) {
+	ls, err := defaults.get()
+	if err != nil {
+		return nil, err
+	}
+
+	// Then apply overwrites on top of defaults.
+	for _, rl := range spec.Process.Rlimits {
+		lt, ok := fromLinuxResource[rl.Type]
+		if !ok {
+			return nil, fmt.Errorf("unknown resource %q", rl.Type)
+		}
+		ls.SetUnchecked(lt, limits.Limit{
+			Cur: rl.Soft,
+			Max: rl.Hard,
+		})
+	}
+	return ls, nil
+}