Notes:
1. This version of NAT66 is a stateful one like NAT44, corresponding to Linux's MASQUERADE target of ip6tables. We can support stateless NAT66 & NPTv6 later by slightly modify the address & port selection logic (maybe just match the rules and skip the entry find).
2. We're using same flag `IFF_NAT` for both NAT44 & NAT66 to make control easier. Which means, if we enable NAT, both NAT44 & NAT66 will be enabled. If we don't want one of them, we can just disable that one in Kconfig.
3. Maybe we can accelerate the checksum adjustment by pre-calculate a difference of checksum, and apply it to each packet, instead of calling `net_chksum_adjust` each time. Just a thought, maybe do it later.
4. IP fragment segments on NAT66 connections are not supported yet.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
since iob offload, ipvx_dev_forward will remove d_iob, if there are multiple
devices, d_iob will be NULL when dev_forward is entered second time. and the
device that receives the packet cannot process the packet after forwarding it
so the iob copy is added.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
Add basic functions for NAT (NAPT), remaining some logic unimplemented (UDP, ICMP, port assignment, etc). NAT for TCP can work now (unless port conflicts).
Outbound: LAN -> Forward -> NAT(only if targeting at WAN) -> WAN
Inbound: WAN -> NAT(only from WAN, change dest) -> Forward -> LAN
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
f_domain is used to determine protocol family when CONFIG_NET_IPv4 and CONFIG_NET_IPv6 are both defined, but not correctly used in ipv4_dev_forward because of typo (there's not a config named CONFIG_NET_IPv5) which may cause IPv4 packets to be forwarded as IPv6.
Signed-off-by: wengzhe <wengzhe@xiaomi.com>
since it is impossible to track producer and consumer
correctly if TCP/IP stack pass IOB directly to netdev
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Iobinstrumentation
* mm/iob: Introduces producer/consumer id to every iob call. This is so that the calls can be instrumented to monitor the IOB resources.
* iob instrumentation - Merges producer/consumer enumeration for simpler IOB user.
* fs/procfs: Starts adding support for /proc/iobinfo
* fs/procfs: Finishes first pass of simple IOB user stastics and /proc/iobinfo entry
Approved-by: Gregory Nutt <gnutt@nuttx.org>
This makes the user interface a little hostile. People thing of an MTU of 1500 bytes, but the corresponding packet is really 1514 bytes (including the 14 byte Ethernet header). A more friendly solution would configure the MTU (as before), but then derive the packet buffer size by adding the MAC header length. Instead, we define the packet buffer size then derive the MTU.
The MTU is not common currency in networking. On the wire, the only real issue is the MSS which is derived from MTU by subtracting the IP header and TCP header sizes (for the case of TCP). Now it is derived for the PKTSIZE by subtracting the IP header, the TCP header, and the MAC header sizes. So we should be all good and without the recurring 14 byte error in MTU's and MSS's.
Squashed commit of the following:
Trivial update to fix some spacing issues.
net/: Rename several macros containing _MTU to _PKTSIZE.
net/: Rename CONFIG_NET_SLIP_MTU to CONFIG_NET_SLIP_PKTSIZE and similarly for CONFIG_NET_TUN_MTU. These are not the MTU which does not include the size of the link layer header. These are the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename CONFIG_NET_6LOWPAN_MTU to CONFIG_NET_6LOWPAN_PKTSIZE and similarly for CONFIG_NET_TUN_MTU. These are not the MTU which does not include the size of the link layer header. These are the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename CONFIG_NET_ETH_MTU to CONFIG_NET_ETH_PKTSIZE. This is not the MTU which does not include the size of the link layer header. This is the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename the file d_mtu in the network driver structure to d_pktsize. That value saved there is not the MTU. The packetsize is the memory large enough to hold the maximum packet PLUS the size of the link layer header. The MTU does not include the link layer header.
