git: 883c726a39b6 - main - Document nvlist-based set/get ifcaps

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=883c726a39b6bdd403e0ea55856e056b670b43e9

commit 883c726a39b6bdd403e0ea55856e056b670b43e9
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2022-05-08 23:10:10 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2022-05-24 20:59:32 +0000

    Document nvlist-based set/get ifcaps
    
    Reviewed by:    debdrup, hselasky, jhb, kp (previous version)
    Sponsored by:   NVIDIA Networking
    MFC after:      3 weeks
    Differential revision:  https://reviews.freebsd.org/D32551
---
 share/man/man9/ifnet.9 | 70 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

diff --git a/share/man/man9/ifnet.9 b/share/man/man9/ifnet.9
index d604a2092e19..dd203cb5580b 100644
--- a/share/man/man9/ifnet.9
+++ b/share/man/man9/ifnet.9
@@ -28,7 +28,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 28, 2020
+.Dd May 24, 2022
 .Dt IFNET 9
 .Os
 .Sh NAME
@@ -1334,6 +1334,74 @@ and
 .Va if_data.ifi_hwassist
 appropriately.
 .Pp
+.It Dv SIOCGIFCAPNV
+.Xr NV 9
+version of the
+.Dv SIOCGIFCAP
+ioctl.
+Caller must provide a pointer to
+.Vt struct ifreq_cap_nv
+as
+.Fa data ,
+where the member
+.Dv buffer
+points to some buffer containing
+.Dv buf_length
+bytes.
+The serialized nvlist with description of the device capabilities
+is written to the buffer.
+If buffer is too short, the structure is updated with
+.Dv buffer
+member set to
+.Dv NULL ,
+.Dv length
+set to the minimal required length, and error
+.Er EFBIG
+is returned.
+.Pp
+Elements of the returned nvlist for simple capabilities are boolean,
+identified by names.
+Presence of the boolean element means that corresponding capability is
+supported by the interface.
+Element's value describes the current configured state:
+.Dv true
+means that the capability is enabled, and
+.Dv false
+that it is disabled.
+.Pp
+Driver indicates support for both
+.Dv SIOCGIFCAPNV
+and
+.Dv SIOCSIFCAPNV
+requests by setting
+.Dv IFCAP_NV
+non-modifiable capability bit in
+.Dv if_capabilities .
+.Pp
+.It Dv SIOCSIFCAPNV
+.Xr NV 9
+version of the
+.Dv SIOCSIFCAP
+ioctl.
+Caller must provide the pointer to
+.Vt struct ifreq_cap_nv
+as
+.Fa data ,
+where the member
+.Dv buffer
+points to serialized nvlist of
+.Dv length
+bytes.
+Each element of nvlist describes a requested update of one capability,
+identified by the element name.
+For simple capabilities, the element must be boolean.
+Its
+.Dv true
+value means that the caller asks to enable the capability, and
+.Dv false
+value to disable.
+Only capabilities listed in the nvlist are affected by the call.
+.Pp
 .It Dv SIOCSIFFIB
 Sets interface FIB.
 Caller must have appropriate privilege.