net: ipv6: router advertisement message length should be within limits

The argument len passed to function process_ra is the length of the IPv6
router advertisement message and needs to be between 0 and MTU because
it is assigned to remaining_option_len and used as a loop variable.

Addresses-Coverity-ID: 450971 ("TAINTED_SCALAR")
Signed-off-by: Ehsan Mohandesi <emohandesi@linux.microsoft.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

net: ipv6: Add support for default gateway discovery.

In IPv6, the default gateway and prefix length are determined by receiving
a router advertisement as defined in -
https://www.rfc-editor.org/rfc/rfc4861.

Add support for sending router solicitation (RS) and processing router
advertisements (RA).

If the RA has prefix info option and following conditions are met, then
gatewayip6 and net_prefix_length of ip6addr env variables are initialized.
These are later consumed by IPv6 code for non-local destination IP.

- "Router Lifetime" != 0
- Prefix is NOT link-local prefix (0xfe80::/10)
- L flag is 1
- "Valid Lifetime" != 0

Timing Parameters:
- MAX_RTR_SOLICITATION_DELAY (0-1s)
- RTR_SOLICITATION_INTERVAL (4s) (min retransmit delay)
- MAX_RTR_SOLICITATIONS (3 RS transmissions)

The functionality is enabled by CONFIG_IPV6_ROUTER_DISCOVERY and invoked
automatically from net_init_loop().

Signed-off-by: Ehsan Mohandesi <emohandesi@linux.microsoft.com>
Tested-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>Reviewed-by:
Tested-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Tested-by: Sergei Antonov <saproj@gmail.com>
Reviewed-by: Sergei Antonov <saproj@gmail.com>

net: don't memcpy to NULL

In ndisc_receive() 7 bytes are copied from a buffer of size 6 to NULL.

net_nd_packet_mac is a pointer. If it is NULL, we should set it to the
address of the buffer with the MAC address.

Addresses-Coverity-ID: 430974 ("Out-of-bounds access")
Fixes: c6610e1d90ea ("net: ipv6: Add Neighbor Discovery Protocol (NDP)")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>

net: ipv6: Add Neighbor Discovery Protocol (NDP)

Implement basic of NDP. It doesn't include such things as Router
Solicitation, Router Advertisement and Redirect. It just has Neighbor
Solicitation and Neighbor Advertisement. Only these two features are used
in u-boot IPv6. Implementation of some NDP functions uses API that was
exposed in "net: ipv6: Add IPv6 basic primitives".

Also this patch inlcudes update in Makefile to build NDP.

Series-changes: 3
- Added structures and functions descriptions
- Fixed style problems

Series-changes: 4
- Fixed structures and functions description style

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

net: ipv6: Add support for default gateway discovery.

In IPv6, the default gateway and prefix length are determined by receiving
a router advertisement as defined in -
https://www.rfc-editor.org/rfc/rfc4861.

Add support for sending router solicitation (RS) and processing router
advertisements (RA).

If the RA has prefix info option and following conditions are met, then
gatewayip6 and net_prefix_length of ip6addr env variables are initialized.
These are later consumed by IPv6 code for non-local destination IP.

- "Router Lifetime" != 0
- Prefix is NOT link-local prefix (0xfe80::/10)
- L flag is 1
- "Valid Lifetime" != 0

Timing Parameters:
- MAX_RTR_SOLICITATION_DELAY (0-1s)
- RTR_SOLICITATION_INTERVAL (4s) (min retransmit delay)
- MAX_RTR_SOLICITATIONS (3 RS transmissions)

The functionality is enabled by CONFIG_IPV6_ROUTER_DISCOVERY and invoked
automatically from net_init_loop().

Signed-off-by: Ehsan Mohandesi <emohandesi@linux.microsoft.com>
Tested-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>Reviewed-by:
Tested-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Tested-by: Sergei Antonov <saproj@gmail.com>
Reviewed-by: Sergei Antonov <saproj@gmail.com>

net: don't memcpy to NULL

In ndisc_receive() 7 bytes are copied from a buffer of size 6 to NULL.

net_nd_packet_mac is a pointer. If it is NULL, we should set it to the
address of the buffer with the MAC address.

Addresses-Coverity-ID: 430974 ("Out-of-bounds access")
Fixes: c6610e1d90ea ("net: ipv6: Add Neighbor Discovery Protocol (NDP)")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>

net: ipv6: Add Neighbor Discovery Protocol (NDP)

Implement basic of NDP. It doesn't include such things as Router
Solicitation, Router Advertisement and Redirect. It just has Neighbor
Solicitation and Neighbor Advertisement. Only these two features are used
in u-boot IPv6. Implementation of some NDP functions uses API that was
exposed in "net: ipv6: Add IPv6 basic primitives".

Also this patch inlcudes update in Makefile to build NDP.

Series-changes: 3
- Added structures and functions descriptions
- Fixed style problems

Series-changes: 4
- Fixed structures and functions description style

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

net: don't memcpy to NULL

In ndisc_receive() 7 bytes are copied from a buffer of size 6 to NULL.

net_nd_packet_mac is a pointer. If it is NULL, we should set it to the
address of the buffer with the MAC address.

Addresses-Coverity-ID: 430974 ("Out-of-bounds access")
Fixes: c6610e1d90ea ("net: ipv6: Add Neighbor Discovery Protocol (NDP)")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>

net: ipv6: Add Neighbor Discovery Protocol (NDP)

Implement basic of NDP. It doesn't include such things as Router
Solicitation, Router Advertisement and Redirect. It just has Neighbor
Solicitation and Neighbor Advertisement. Only these two features are used
in u-boot IPv6. Implementation of some NDP functions uses API that was
exposed in "net: ipv6: Add IPv6 basic primitives".

Also this patch inlcudes update in Makefile to build NDP.

Series-changes: 3
- Added structures and functions descriptions
- Fixed style problems

Series-changes: 4
- Fixed structures and functions description style

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

net: ipv6: Add Neighbor Discovery Protocol (NDP)

Implement basic of NDP. It doesn't include such things as Router
Solicitation, Router Advertisement and Redirect. It just has Neighbor
Solicitation and Neighbor Advertisement. Only these two features are used
in u-boot IPv6. Implementation of some NDP functions uses API that was
exposed in "net: ipv6: Add IPv6 basic primitives".

Also this patch inlcudes update in Makefile to build NDP.

Series-changes: 3
- Added structures and functions descriptions
- Fixed style problems

Series-changes: 4
- Fixed structures and functions description style

Signed-off-by: Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>