Because socket objects have a finaliser they must be created carefully, in
case an exception is raised during the population of their members, eg
invalid input argument or out-of-memory when allocating additional arrays.
Prior to the fix in this commit, the finaliser would crash due to
`incoming.udp_raw.array` being an invalid pointer in the following cases:
- if a SOCK_RAW was created with a proto argument that was not an integer
- if a SOCK_DGRAM or SOCK_RAW was created where the allocation of
`lwip_incoming_packet_t` failed
- if an integer was passed in for the socket type but it was not one of
SOCK_STREAM, SOCK_DGRAM or SOCK_RAW
Furthermore, if the allocation of `lwip_incoming_packet_t` failed then it
may have led to corruption within lwIP when freeing `socket->pcb.raw`
because that PCB was not fully set up with its callbacks.
This commit fixes all of these issues by ensuring:
- `pcb.tcp` and `incoming.udp_raw.array` are initialised to NULL early on
- the proto argument is parsed before allocating the PCB
- the allocation of `lwip_incoming_packet_t` occurs befor allocating the
PCB
- `incoming.udp_raw.array` is checked for NULL in the finaliser code
The corresponding test (which already checked most of these causes of
failure) has been updated to include a previously-uncovered scenario.
Signed-off-by: Damien George <damien@micropython.org>
MP_OBJ_SMALL_INT_VALUE would give erroneous results, such as assertion
failures in the coverage build and other oddities like:
>>> s = socket.socket()
>>> s.recv(3.14)
MemoryError: memory allocation failed, allocating 4235896656 bytes
Signed-off-by: Jeff Epler <jepler@gmail.com>
