djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

extmod/modlwip: Register TCP close-timeout callback before closing PCB.

Browse Source 
In d5f0c87bb9 this call to tcp_poll() was
added to put a timeout on closing TCP sockets.  But after calling
tcp_close() the PCB may be freed and therefore invalid, so tcp_poll() can
not be used at that point.  As a fix this commit calls tcp_poll() before
closing the TCP PCB.  If the PCB is subsequently closed and freed by
tcp_close() or tcp_abort() then the PCB will not be on any active list and
the callback will not be executed, which is the desired behaviour (the
_lwip_tcp_close_poll() callback only needs to be called if the PCB remains
active for longer than the timeout).
This commit is contained in:
Damien George 2019-05-29 01:29:48 +10:00
parent 734ada3e29
commit 019dd84af1
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
extmod/modlwip.c
View File

@ -1421,12 +1421,15 @@ STATIC mp_uint_t lwip_socket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_
switch (socket->type) {
case MOD_NETWORK_SOCK_STREAM: {
if (socket->pcb.tcp->state != LISTEN) {
// Schedule a callback to abort the connection if it's not cleanly closed after
// the given timeout. The callback must be set before calling tcp_close since
// the latter may free the pcb; if it doesn't then the callback will be active.
tcp_poll(socket->pcb.tcp, _lwip_tcp_close_poll, MICROPY_PY_LWIP_TCP_CLOSE_TIMEOUT_MS / 500);
}
if (tcp_close(socket->pcb.tcp) != ERR_OK) {
DEBUG_printf("lwip_close: had to call tcp_abort()\n");
tcp_abort(socket->pcb.tcp);
} else {
// If connection not cleanly closed after timeout then abort the connection
tcp_poll(socket->pcb.tcp, _lwip_tcp_close_poll, MICROPY_PY_LWIP_TCP_CLOSE_TIMEOUT_MS / 500);
}
break;
}