Overview

The main part of the QNX Neutrino networking stack is the io-pkt manager. We provide several variants of it with different capabilities:

io-pkt-v4

IPv4 version of the stack with no encryption or Wi-Fi capability built in. This is a "reduced footprint" version of the stack that doesn't support the following:

• IPv6
• Crypto / IPSec
• 802.11 a/b/g Wi-Fi
• Bridging
• GRE / GRF
• Multicast routing
• Multipoint PPP

io-pkt-v4-hc

IPv4 version of the stack that has full encryption and Wi-Fi capability built in and includes hardware-accelerated cryptography capability (Fast IPsec).

io-pkt-v6-hc

IPv6 version of the stack (includes IPv4 as part of v6) that has full encryption and Wi-Fi capability, also with hardware-accelerated cryptography.

We've designed io-pkt to follow as closely as possible the NetBSD networking stack code base and architecture. This provides an optimal path between the IP protocol and drivers, tightly integrating the IP layer with the rest of the stack.

The io-pkt implementation replaces the previous generation of the stack, io-net, and makes significant changes to the QNX Neutrino stack architecture, including the following:

• mount and umount capabilities:
  • Only io-net drivers may be both mounted and unmounted. Other drivers may allow you to detach the driver from the stack, by using the ifconfig iface destroy command (if the driver supports it).
  • Protocols and enhanced stack functionality (e.g., TDP, NAT / IP Filtering) can be mounted, but not unmounted.
• Driver changes:
  • The driver API and behavior have been changed to closely match those of the NetBSD stack, allowing NetBSD drivers to be ported to io-pkt.
  • A shim layer, devnp-shim.so, is provided that lets you use an io-net driver as-is.
  • By default, driver interfaces are no longer sequentially numbered with enx designations; they're named according to driver type (e.g., fxp0 is the interface for an Intel 10/100 driver). You can use the name= driver option (processed by io-pkt) to specify the interface name.
  • Drivers no longer present entries in the name space to be directly opened and accessed with a devctl() command (e.g., open(/dev/io-net/en0)). Instead, a socket file descriptor is opened and queried for interface information. The ioctl() command is then sent to the stack using this device information.
• IP Filtering and NAT are handled through the PF interface with pfctl.
• io-pkt doesn't currently support SCTP.
• In io-pkt loopback-checksumming is controlled via sysctl:

  # sysctl -a | grep do_loopback_cksum
  net.inet.ip.do_loopback_cksum = 0
  net.inet.tcp.do_loopback_cksum = 0
  net.inet.udp.do_loopback_cksum = 0
    

• The nicinfo utility operates slightly differently from the way it did under io-net:
  • The default operation with no arguments is to list information on all interfaces.
  • Under io-net, all Ethernet interface names were in the form enX. Under io-pkt, this name will vary, but you can use the name= driver option (processed by io-pkt) to override this.
  • Ported NetBSD drivers might not support the nicinfo ioctl() command.