Support multiple networks

This is a refresh of Dan William's PR #974 with a rebase and proper
vendoring of ocicni and containernetworking/cni.  It adds the ability
to define multiple networks as so:

podman run --network=net1,net2,foobar ...

Signed-off-by: baude <bbaude@redhat.com>

Closes: #1082
Approved by: baude

vendor/github.com/containernetworking/cni/pkg/version/plugin.go

@@ -18,6 +18,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"strconv"
+	"strings"
 )
 
 // PluginInfo reports information about CNI versioning
@@ -79,3 +81,60 @@ func (*PluginDecoder) Decode(jsonBytes []byte) (PluginInfo, error) {
 	}
 	return &info, nil
 }
+
+// ParseVersion parses a version string like "3.0.1" or "0.4.5" into major,
+// minor, and micro numbers or returns an error
+func ParseVersion(version string) (int, int, int, error) {
+	var major, minor, micro int
+	parts := strings.Split(version, ".")
+	if len(parts) == 0 || len(parts) >= 4 {
+		return -1, -1, -1, fmt.Errorf("invalid version %q: too many or too few parts", version)
+	}
+
+	major, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return -1, -1, -1, fmt.Errorf("failed to convert major version part %q: %v", parts[0], err)
+	}
+
+	if len(parts) >= 2 {
+		minor, err = strconv.Atoi(parts[1])
+		if err != nil {
+			return -1, -1, -1, fmt.Errorf("failed to convert minor version part %q: %v", parts[1], err)
+		}
+	}
+
+	if len(parts) >= 3 {
+		micro, err = strconv.Atoi(parts[2])
+		if err != nil {
+			return -1, -1, -1, fmt.Errorf("failed to convert micro version part %q: %v", parts[2], err)
+		}
+	}
+
+	return major, minor, micro, nil
+}
+
+// GreaterThanOrEqualTo takes two string versions, parses them into major/minor/micro
+// nubmers, and compares them to determine whether the first version is greater
+// than or equal to the second
+func GreaterThanOrEqualTo(version, otherVersion string) (bool, error) {
+	firstMajor, firstMinor, firstMicro, err := ParseVersion(version)
+	if err != nil {
+		return false, err
+	}
+
+	secondMajor, secondMinor, secondMicro, err := ParseVersion(otherVersion)
+	if err != nil {
+		return false, err
+	}
+
+	if firstMajor > secondMajor {
+		return true, nil
+	} else if firstMajor == secondMajor {
+		if firstMinor > secondMinor {
+			return true, nil
+		} else if firstMinor == secondMinor && firstMicro >= secondMicro {
+			return true, nil
+		}
+	}
+	return false, nil
+}