Rework port parsing to support --expose and -P

As part of this, make a major change to the type we use to
represent port mappings in SpecGen (from using existing OCICNI
structs to using our own custom one). This struct has the
advantage of supporting ranges, massively reducing traffic over
the wire for Podman commands using them (for example, the
`podman run -p 5000-6000` command will now send only one struct
instead of 1000). This struct also allows us to easily validate
which ports are in use, and which are not, which is necessary for
--expose.

Once we have parsed the ports from the new struct, we can produce
an accurate map including all currently requested ports, and use
that to determine what ports need to be exposed (some requested
exposed ports may already be included in a mapping from --publish
and will be ignored) and what open ports on the host we can map
them to.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 46 insertions, 6 deletions

diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index 20c8f8800..4f1c4fde1 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -6,7 +6,6 @@ import (
 
 	"github.com/containers/image/v5/manifest"
 	"github.com/containers/storage"
-	"github.com/cri-o/ocicni/pkg/ocicni"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -306,11 +305,23 @@ type ContainerNetworkConfig struct {
 	// PortBindings is a set of ports to map into the container.
 	// Only available if NetNS is set to bridge or slirp.
 	// Optional.
-	PortMappings []ocicni.PortMapping `json:"portmappings,omitempty"`
-	// PublishImagePorts will publish ports specified in the image to random
-	// ports outside.
-	// Requires Image to be set.
-	PublishImagePorts bool `json:"publish_image_ports,omitempty"`
+	PortMappings []PortMapping `json:"portmappings,omitempty"`
+	// PublishExposedPorts will publish ports specified in the image to
+	// random unused ports (guaranteed to be above 1024) on the host.
+	// This is based on ports set in Expose below, and any ports specified
+	// by the Image (if one is given).
+	// Only available if NetNS is set to Bridge or Slirp.
+	PublishExposedPorts bool `json:"publish_image_ports,omitempty"`
+	// Expose is a number of ports that will be forwarded to the container
+	// if PublishExposedPorts is set.
+	// Expose is a map of uint16 (port number) to a string representing
+	// protocol. Allowed protocols are "tcp", "udp", and "sctp", or some
+	// combination of the three separated by commas.
+	// If protocol is set to "" we will assume TCP.
+	// Only available if NetNS is set to Bridge or Slirp, and
+	// PublishExposedPorts is set.
+	// Optional.
+	Expose map[uint16]string `json:"expose,omitempty"`
 	// CNINetworks is a list of CNI networks to join the container to.
 	// If this list is empty, the default CNI network will be joined
 	// instead. If at least one entry is present, we will not join the
@@ -410,6 +421,35 @@ type NamedVolume struct {
 	Options []string
 }
 
+// PortMapping is one or more ports that will be mapped into the container.
+type PortMapping struct {
+	// HostIP is the IP that we will bind to on the host.
+	// If unset, assumed to be 0.0.0.0 (all interfaces).
+	HostIP string `json:"host_ip,omitempty"`
+	// ContainerPort is the port number that will be exposed from the
+	// container.
+	// Mandatory.
+	ContainerPort uint16 `json:"container_port"`
+	// HostPort is the port number that will be forwarded from the host into
+	// the container.
+	// If omitted, will be assumed to be identical to
+	HostPort uint16 `json:"host_port,omitempty"`
+	// Range is the number of ports that will be forwarded, starting at
+	// HostPort and ContainerPort and counting up.
+	// This is 1-indexed, so 1 is assumed to be a single port (only the
+	// Hostport:Containerport mapping will be added), 2 is two ports (both
+	// Hostport:Containerport and Hostport+1:Containerport+1), etc.
+	// If unset, assumed to be 1 (a single port).
+	// Both hostport + range and containerport + range must be less than
+	// 65536.
+	Range uint16 `json:"range,omitempty"`
+	// Protocol is the protocol forward.
+	// Must be either "tcp", "udp", and "sctp", or some combination of these
+	// separated by commas.
+	// If unset, assumed to be TCP.
+	Protocol string `json:"protocol,omitempty"`
+}
+
 // NewSpecGenerator returns a SpecGenerator struct given one of two mandatory inputs
 func NewSpecGenerator(arg string, rootfs bool) *SpecGenerator {
 	csc := ContainerStorageConfig{}