sbin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

ping: low-effort fix to make it compilable without inet

ifconfig: Avoid issues with trying to negate unsigned values.

The if_flags and if_cap fields hold a bitmask of flags. If a flag is
the MSB of the field, then the logic in setifflags and setifcap which
uses a < 0 check does the wrong thing (it tries to clear the flag
rather than setting it). Also, trying to use -<FOO> doesn't actually
work as the result is a nop. To fix, stop overloading setifcap and
setifflags and instead add new dedicated action functions clearifcap
and clearifflags for clearing a flag. The value passed in the
argument to the command is now always the raw flag.

This was reported by a GCC warning after raising WARNS:

sbin/ifconfig/ifconfig.c:2061:33: error: integer overflow in expression '-2147483648' of type 'int' results in '-2147483648' [-Werror=overflow]
2061 | DEF_CMD("-txtlsrtlmt", -IFCAP_TXTLS_RTLMT, setifcap),
| ^

Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D40608

ifconfig: remove (most of) the usages of global 'struct ifreq ifr'.

It is hard to reason about the contents of 'ifr' at any given time
as nearly every function sets random fields or pointers in this
structure.
Use local on-stack clean 'struct ifreq' for each function instead.

Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D40534
MFC after: 2 weeks

ifconfig: eliminate global 'verbose' and 'printkey' variables

Reviewed By: kp
Differential Revision: https://reviews.freebsd.org/D40427
MFC after: 2 weeks

ifconfig: add if_ctx argument to the generic and ifclone callbacks.

This is the continuation of the ifconfig cleanup work. This change is
a pre-requsite for the next changes removing some of the global variables.
It will also help in implementing functionality via Netlink instead of ioctl.
No functional changes intended.
* vxlan_cb() was removed as it contained no code
* ioctl_ifcreate() was renamed to ifcreate_ioctl() to follow the other
netlink/ioctl function naming. Netlink and ioctl provide _different_
interfaces and it's not possible to have a unified interface object
that can be filled by either netlink or ioctl implementations. With that
in mind, I'm leaning more to the function_<nl|ioctl> postfix pattern,
than doing ioctl_ or netlink_ prefix.

Reviewed By: kp
Differential Revision: https://reviews.freebsd.org/D40426
MFC after: 2 weeks

ifconfig: fix warnings #2

Fix all -Wparameter-unused and cast alignment

Differential Revision: https://reviews.freebsd.org/D40303
MFC after: 2 weeks

ifconfig: introduce `ifconfig_context` to store current global state.

The structure consists of all current context - arguments,
open sockets, current family and so on.

Pass this structure as a first argument to most of the af_ menthods.
This allows to propagate and update shared data without using
global variables.

The diff is pretty large, but de-facto mechanical. All changes
except the structure setup in ifconfig[_netlink].c are one-line
mechanical changes.

Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D40239
MFC after: 2 weeks

ifconfig: cleanup warnings #1

Cleanup compiler warnings in preparation to set Wextra and remove WARNS?=2

Differential Revision: https://reviews.freebsd.org/D40238
MFC after: 2 weeks

Ensure consistent error messages from ifconfig(8).

If multiple threads are invoking "ifconfig XXX create" a race may occur
which can lead to two different error messages for the same error.

a) ifconfig: SIOCIFCREATE2: File exists
b) ifconfig: interface XXX already exists

This patch ensures ifconfig prints the same error code
for the same case.

Reviewed by: imp@ and kib@
Differential Revision: https://reviews.freebsd.org/D27380
MFC after: 1 week
Sponsored by: Mellanox Technologies // NVIDIA Networking

Add support for stacked VLANs (IEEE 802.1ad, AKA Q-in-Q).

802.1ad interfaces are created with ifconfig using the "vlanproto" parameter.
Eg., the following creates a 802.1Q VLAN (id #42) over a 802.1ad S-VLAN
(id #5) over a physical Ethernet interface (em0).

ifconfig vlan5 create vlandev em0 vlan 5 vlanproto 802.1ad up
ifconfig vlan42 create vlandev vlan5 vlan 42 inet 10.5.42.1/24

VLAN_MTU, VLAN_HWCSUM and VLAN_TSO capabilities should be properly
supported. VLAN_HWTAGGING is only partially supported, as there is
currently no IFCAP_VLAN_* denoting the possibility to set the VLAN
EtherType to anything else than 0x8100 (802.1ad uses 0x88A8).

Submitted by: Olivier Piras
Sponsored by: RG Nets
Differential Revision: https://reviews.freebsd.org/D26436

Add two new ifnet capabilities for hw checksumming and TSO for VXLAN traffic.

These are similar to the existing VLAN capabilities.

Reviewed by: kib@
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D25873

Add support for IPv6 scoped addresses to vxlan

MFC after: 2 weeks

Use consistent name for the vxlan VNI parameter name and provide shorthand

Submitted by: hrs
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D2868

Replace N #defines with nitems to simplify ifconfig code slightly

MFC after: 1 week

Stop including if_var.h from userland.

Sponsored by: Nginx, Inc.

Prefix all the vxlan ifconfig commands so they are unique

And rehook ifvxlan back into the build.

Add vxlan interface

vxlan creates a virtual LAN by encapsulating the inner Ethernet frame in
a UDP packet. This implementation is based on RFC7348.

Currently, the IPv6 support is not fully compliant with the specification:
we should be able to receive UPDv6 packets with a zero checksum, but we
need to support RFC6935 first. Patches for this should come soon.

Encapsulation protocols such as vxlan emphasize the need for the FreeBSD
network stack to support batching, GRO, and GSO. Each frame has to make
two trips through the network stack, and each frame will be at most MTU
sized. Performance suffers accordingly.

Some latest generation NICs have begun to support vxlan HW offloads that
we should also take advantage of. VIMAGE support should also be added soon.

Differential Revision: https://reviews.freebsd.org/D384
Reviewed by: gnn
Relnotes: yes