Allocate the device buffer only if the protocol really need to send data.
not all protocols require the driver to prepare additional iob before
sending, especially UDP, each iob reserves l2/l3 header in advance
after prepare write buffer, net device could reuse this entry to send directly
Signed-off-by: chao an <anchao@xiaomi.com>
The MLD implementation did not follow the RFC correctly when it is the Querier. The Querier should use a general query and get query messages from all members of all groups. This would be driven by a single timer per sub-nset since all groups are queried at once. Instead, the design used a Multicast Address Specific Query with one timer per group and ignores groups that we are not members of.
Similary, the MLDv1 compatibility timer should be a single, separate timer, not a per-group timer.
net/mld: Group may be NULL when sending a general query
net/mld: More updates from comparison with roughly leveraged code and the MDL RFCs 2710 and 3810.
net/mld: More updated from comparison with roughly leveraged code and the MDL RFCs 2710 and 3810.
net/mld: Beginning comparison with roughly leveraged code and the MDL RFCs 2710 and 3810.
net/mld: The MLD logic now compiles and is much less toxic. It still is not a proper MLD implementation: (1) It is basically a port of IGMP, tweaked to work with IPv6 and ICMPv6 MLD messages, (2) it needs a proper analysis and comparison with RFC 3810, and (3) it is completely untested. For this reason, it will remain EXPERIMENTAL for some time.
net/mld: Add some missing macros, more fixes related to IPv6 vs IPv4 types,
net/mld: More compilation cleaning. Most fixups for IPv6 vs IPv4 types.
net/mld: Hook crudely converted .c files into build system and resolve a few of the many, many compilation/design problems.
net/mld: Add support for MLD statistics.
net/mld: Hook in MLD poll and packet transmission logic.
net/mld: Change references to IPv4 definitions to IPv6 definitions; Remove mld_input() since MLD piggybacks on ICMPv6 input. Add functions to catch MLD messages dispatched by ICMPv6 input logic.
net/mld: As a starting point, copy all net/igmp/*.c files to net/mld/. and change all occurrences of igmp (or IGMP) to mld (or MLD).
net/mld: More compilation cleaning. Most fixups for IPv6 vs IPv4 types.
net/mld: Hook crudely converted .c files into build system and resolve a few of the many, many compilation/design problems.
net/mld: Add support for MLD statistics.
net/mld: Hook in MLD poll and packet transmission logic.
net/mld: Change references to IPv4 definitions to IPv6 definitions; Remove mld_input() since MLD piggybacks on ICMPv6 input. Add functions to catch MLD messages dispatched by ICMPv6 input logic.
net/mld: As a starting point, copy all net/igmp/*.c files to net/mld/. and change all occurrences of igmp (or IGMP) to mld (or MLD).
