func()

in pkg/iptableswrapper/fake_iptables.go [96:157]
49 lines of code
19 McCabe index (conditional complexity)

func (f *FakeIPTables) restoreTable(newDump *iptest.IPTablesDump, newTable *iptest.Table, flush iptables.FlushFlag, counters iptables.RestoreCountersFlag) error {
	oldTable, err := f.fake.Dump.GetTable(newTable.Name)
	if err != nil {
		return err
	}

	backupChains := make([]iptest.Chain, len(oldTable.Chains))
	copy(backupChains, oldTable.Chains)

	// Update internal state
	if flush == iptables.FlushTables {
		oldTable.Chains = make([]iptest.Chain, 0, len(newTable.Chains))
	}
	for _, newChain := range newTable.Chains {
		oldChain, _ := f.fake.Dump.GetChain(newTable.Name, newChain.Name)
		switch {
		case oldChain == nil && newChain.Deleted:
			// no-op
		case oldChain == nil && !newChain.Deleted:
			oldTable.Chains = append(oldTable.Chains, newChain)
		case oldChain != nil && newChain.Deleted:
			_ = f.DeleteChain(newTable.Name, newChain.Name)
		case oldChain != nil && !newChain.Deleted:
			// replace old data with new
			oldChain.Rules = newChain.Rules
			if counters == iptables.RestoreCounters {
				oldChain.Packets = newChain.Packets
				oldChain.Bytes = newChain.Bytes
			}
		}
	}

	// Now check that all old/new jumps are valid
	for _, chain := range oldTable.Chains {
		for _, rule := range chain.Rules {
			if rule.Jump == nil {
				continue
			}
			if f.builtinTargets.Has(rule.Jump.Value) {
				continue
			}

			jumpedChain, _ := f.fake.Dump.GetChain(oldTable.Name, iptables.Chain(rule.Jump.Value))
			if jumpedChain == nil {
				newChain, _ := newDump.GetChain(oldTable.Name, iptables.Chain(rule.Jump.Value))
				if newChain != nil {
					// rule is an old rule that jumped to a chain which
					// was deleted by newDump.
					oldTable.Chains = backupChains
					return fmt.Errorf("deleted chain %q is referenced by existing rules", newChain.Name)
				} else {
					// rule is a new rule that jumped to a chain that was
					// neither created nor pre-existing
					oldTable.Chains = backupChains
					return fmt.Errorf("rule %q jumps to a non-existent chain", rule.Raw)
				}
			}
		}
	}

	return nil
}