Re: [PATCH v2] netdevice.7: Update documentation for SIOCGIFADDR SIOCSIFADDR SIOCDIFADDR

["Pali Rohár" <pali@kernel.org>]

On Saturday 02 January 2021 19:39:52 Pali Rohár wrote:
> Also add description for struct in6_ifreq which is used for IPv6 addresses.
> 
> SIOCSIFADDR and SIOCDIFADDR can be used to add or delete IPv6 address and
> pppd is using these ioctls for a long time. Surprisingly SIOCDIFADDR cannot
> be used for deleting IPv4 address but only for IPv6 addresses.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
>  man7/netdevice.7 | 50 +++++++++++++++++++++++++++++++++++++++++-------
>  1 file changed, 43 insertions(+), 7 deletions(-)

Hello! Is something else needed for this patch?

> diff --git a/man7/netdevice.7 b/man7/netdevice.7
> index 488e83d9a..12f94bfd7 100644
> --- a/man7/netdevice.7
> +++ b/man7/netdevice.7
> @@ -55,9 +55,26 @@ struct ifreq {
>  .EE
>  .in
>  .PP
> +AF_INET6 is an exception.
> +It passes an
> +.I in6_ifreq
> +structure:
> +.PP
> +.in +4n
> +.EX
> +struct in6_ifreq {
> +    struct in6_addr     ifr6_addr;
> +    u32                 ifr6_prefixlen;
> +    int                 ifr6_ifindex; /* Interface index */
> +};
> +.EE
> +.in
> +.PP
>  Normally, the user specifies which device to affect by setting
>  .I ifr_name
> -to the name of the interface.
> +to the name of the interface or
> +.I ifr6_ifindex
> +to the index of the interface.
>  All other members of the structure may
>  share memory.
>  .SS Ioctls
> @@ -142,13 +159,32 @@ IFF_ISATAP:Interface is RFC4214 ISATAP interface.
>  .PP
>  Setting the extended (private) interface flags is a privileged operation.
>  .TP
> -.BR SIOCGIFADDR ", " SIOCSIFADDR
> -Get or set the address of the device using
> -.IR ifr_addr .
> -Setting the interface address is a privileged operation.
> -For compatibility, only
> +.BR SIOCGIFADDR ", " SIOCSIFADDR ", " SIOCDIFADDR
> +Get, set or delete the address of the device using
> +.IR ifr_addr ,
> +or
> +.I ifr6_addr
> +with
> +.IR ifr6_prefixlen .
> +Setting or deleting the interface address is a privileged operation.
> +For compatibility,
> +.B SIOCGIFADDR
> +returns only
>  .B AF_INET
> -addresses are accepted or returned.
> +addresses,
> +.B SIOCSIFADDR
> +accepts
> +.B AF_INET
> +and
> +.B AF_INET6
> +addresses and
> +.B SIOCDIFADDR
> +deletes only
> +.B AF_INET6
> +addresses.
> +.B AF_INET
> +address can be deleted by setting zero address via
> +.BR SIOCSIFADDR .
>  .TP
>  .BR SIOCGIFDSTADDR ", " SIOCSIFDSTADDR
>  Get or set the destination address of a point-to-point device using
> -- 
> 2.20.1
>