This re-works the persist timer to have the following behavior:
1) Only start persist timer when a buffered segment doesn't fit within
the current window and there is no in-fligh data. Previously, the
persist timer was always started when the window went to zero even
if there was no buffered data (since timer was managed in receive
pathway rather than transmit pathway)
2) Upon first fire of persist timer, fill the remaining window if
non-zero by splitting the unsent segment. If split segment is sent,
persist timer is stopped, RTO timer is now ensuring reliable window
updates
3) If window is already zero when persist timer fires, send 1 byte probe
4) Persist timer and zero window probe should only be active when the
following are true:
* no in-flight data (pcb->unacked == NULL)
* when there is buffered data (pcb->unsent != NULL)
* when pcb->unsent->len > pcb->snd_wnd
lwip_itoa would output the number 0 as \0. This fixes the issue by
adding a special check before the normal conversion loop
This was found via shell cmd idxtoname and win32 port. "lo0" should
be returned for index 1
These are now defined to return != SYS_ARCH_TIMEOUT on success rather than the time
waiting. The returned times were unused by lwip and this simplifies at
least some implementations.
Signed-off-by: goldsimon <goldsimon@gmx.de>
This switches netconn_gethostbyname to use tcpip_send_msg_wait_sem to
take advantage of core locking support when enabled.
tcpip_send_msg_wait_sem handles blocking for the non-core locking case,
so we can remove the manual blocking in netconn_gethostbyname. For the
core locking case, we need to block if waiting on DNS callback. To
achieve this, we unlock the core and wait in lwip_netconn_do_gethostbyname.
This is the similar approach that netconn_write takes when it needs to
block to continue the write (see lwip_netconn_do_write)
This improves performance in the core locking case and is no change
for the non-core locking case
This commit adds a timeout to the zero-window probing (persist timer)
mechanism. LwIP has not historically had a timeout for the persist
timer, leading to unbounded blocking if connection drops during the
zero-window condition
This commit also adds two units test, one to check the RTO timeout
and a second to check the zero-window probe timeout
While TCP_OVERSIZE works only when tcp_write() is used with
TCP_WRITE_FLAG_COPY, this new code achieves
similar benefits for the use case that the caller manages their own
send buffers and passes successive chunks of those to tcp_write()
without TCP_WRITE_FLAG_COPY.
In particular, if a buffer is passed to
tcp_write() that is adjacent in memory to the previously passed
buffer, it will be combined into the previous ROM pbuf reference
whenever possible, thus extending that ROM pbuf rather than allocating
a new ROM pbuf.
For the aforementioned use case, the advantages of this code are
twofold:
1) fewer ROM pbufs need to be allocated to send the same data, and,
2) the MAC layer gets outgoing TCP packets with shorter pbuf chains.
Original patch by Ambroz Bizjak <ambrop7@gmail.com>
Edited by David van Moolenbroek <david@minix3.org>
Signed-off-by: goldsimon <goldsimon@gmx.de>
