The reset is necessary at the beginning of the function, because of
the errno logic in the error path (set errno to EINVAL if not set).
If errno is already set when calling the function, and the function
fails, the previous errno value will be inherited.
The companion libnetmap changes for the "offsets" kernel support added
in a6d768d845. This includes code to parse the "@offset=NNN"
option that can be appended to the port name by any nmport_* application.
Example:
# pkt-gen -i 'netmap:em0@offset=16'
Use uintptr_t to cast a uint64_t to a pointer type.
Yeah, it isn't technically correct for platforms with pointers
> 64 bits, but it's fine here.
This fixes 32 bit compat library builds on amd64 and also
mips32 builds.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D26790
This changeset introduces the new libnetmap library for writing
netmap applications.
Before libnetmap, applications could either use the kernel API
directly (e.g. NIOCREGIF/NIOCCTRL) or the simple header-only-library
netmap_user.h (e.g. nm_open(), nm_close(), nm_mmap() etc.)
The new library offers more functionalities than netmap_user.h:
- Support for complex netmap options, such as external memory
allocators or per-buffer offsets. This opens the way to future
extensions.
- More flexibility in the netmap port bind options, such as
non-numeric names for pipes, or the ability to specify the netmap
allocator that must be used for a given port.
- Automatic tracking of the netmap memory regions in use across the
open ports.
At the moment there is no man page, but the libnetmap.h header file
has in-depth documentation.
Reviewed by: hrs
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26171
