Generally speaking, packets with a loopback destination address -
127.0.0.1 for IPv4 and ::1 for IPv6 - should not be accepted on
non-loopback interfaces. For IPv4, this is implied by RFC 1122
Sec. 3.2.1.3. For IPv6, it is mandated by RFC 4291 Sec. 2.5.3.
Failure to perform this filtering may have security implications, as
applications that bind sockets to loopback addresses may not expect
that nodes on the local external network be able to produce traffic
that will arrive at such sockets.
With this patch, lwIP drops packets that are sent to a loopback
address but do not originate from the interface that has the loopback
address assigned to it. This approach works regardless of whether it
is lwIP or the system using it that implements a loopback netif. The
only exception that must be made is for configurations that enable
netif packet loopback but disable the lwIP loopback netif: in that
case, loopback packets are routed across non-loopback netifs and would
thus be lost by the new filter as well.
For IPv6, loopback-destined packets are also no longer forwarded; the
IPv4 forwarding code already had a check for that.
As a small performance improvement, the IPv6 link-local/loopback
address check is now performed only once per packet rather than
repeatedly for every candidate netif.
In general, netif_default may be NULL, and various places in the code
already check for this case before attempting to dereference the
netif_default pointer. Some places do not perform this check though,
and may cause null pointer dereferences if netif_default is not set.
This patch adds NULL checks to those places as well.
bind() may change IP type when previous type is IPADDR_TYPE_ANY
connect() IP type must exactly match bind IP type
Use correct IPADDRx_ANY type when calling ip_route()
This commit returns LwIP to previous behavior where if the next unsent
segment can't be sent due to the current send window, we start the
persist timer. This is done to engage window probing in the case that
the subsequent window update from the receiver is dropped, thus
preventing connection deadlock
This commit refines the previous logic to only target the following case:
1) Next unsent segment doesn't fit within the send window (not
congestion) and there is some room in the window
2) Unacked queue is empty (otherwise data is inflight and the RTO timer
will take care of any dropped window updates)
See commit d8f090a759 (which removed this
behavior) to reference the old logic. The old logic falsely started the
persit timer when the RTO timer was already running.
This commit cleans up a duplicate #if check for LWIP_WND_SCALE in init.c
which was already under #if LWIP_WND_SCALE
This commit also improves documentation for TCP_WND in the window scaling
case to communicate TCP_WND is always the calculated (scaled) window value,
not the value reported in the TCP header
Our developers were confused by having to set both the window and scaling
factor and only after studying the usage of TCP_WND throughout the code, was
it determined to be the calculated (scaled) window
p needs to point to LWIP_MEM_ALIGN(memp_pools[i]->base) otherwise it will cause
assertion in overflow checking.
Fixes: c838e1ed5b ("Implement possibility to declare private memory pools")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
When memp_free_pool was split out from memp_free (c838e1ed5b),
the check for freeing the null pointer was lost.
This resulted in the null value being put back in the list of free
objects, causing all subsequent allocations of that type to fail.
The mld_group structure no longer has a 'netif' field, as such
structures are now linked from the corresponding netif structure.
For conditional checksumming, use the calling function's netif
reference instead.
This comment is incorrect since commit 7d0dab9d7d
"partly fixed bug #25882: TCP hangs on MSS > pcb->snd_wnd
(by not creating segments bigger than half the window)".
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Let lwip use functions/macros prefixed by lwip_ internally to avoid naming clashes with external #includes.
Remove over-complicated #define handling in def.h
Make functions easier to override in cc.h. The following is sufficient now (no more LWIP_PLATFORM_BYTESWAP):
#define lwip_htons(x) <your_htons>
#define lwip_htonl(x) <your_htonl>
TCP's snd_nxt represents the next sequence number after sent data, and
as such does not cover any unsent data queued on the connection. The
current implementation does not take the latter point into account
when processing FIN acknowledgments, mistakenly assuming that an
outgoing FIN is ACK'ed when the acknowledgment covers up to snd_nxt
while there is still unsent data. This patch adds a check for unsent
data to correct this, effectively preventing that TCP connections are
closed prematurely.
It is possible that the byte sent as a zero window probe is accepted
and acknowledged by the receiver side without the window being opened.
In that case, the stream has effectively advanced by one byte, and
since lwIP did not take this into account on the sender side, the
result was a desynchronization between the sender and the receiver.
That situation could occur even on a lwIP loopback device, after
filling up the receiver side's receive buffer, and resulted in an ACK
storm. This patch corrects the problem by advancing the sender's next
sequence number by one as needed when sending a zero window probe.
delay_time and stale_time are ticks now.
reachable_time and invalidation_timer are untouched since they may originate from telegram values -> not converting them to ticks avoids an integer division
commit 8c52afb6ca ("igmp: Optimize code by always skipping the first entry in the linked groups list - it is always the "allsystems" entry")
accidently changes the code logic. it should check groupref rather than group.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reasoning:
- Makes code in single-netif case perform better and smaller
- IGMP / MLD6 code is a little bit easier to read and understand
- Easier to get multicast groups per netif when implementing drivers
Downside: In multi-netif mode, there are two more pointers on each netif, even if IGMP/MLD6 is not used on it. But these systems should not be so memory-constrained that this will matter.
When leaving a multicast group, remove the group from the list
before invoking the MAC filter callback. This avoids the need
for the callee to skip over the group that is about to be deleted.
This commit adds support to the sanity checks in init.c to ensure that
PBUF_POOL is in use
In ports with drivers/netifs that use PBUF_REF for the RX pathway, there
is no need for the PBUF_POOL memory pool. This allows the port to define
PBUF_POOL_SIZE to 0
commit 44e1a2d8e2 accidently includes below changes in tcp_listen_with_backlog
- tcp_backlog_set(lpcb, backlog);
+ lpcb->backlog = backlog;
Thus pass 0 to the backlog parameter of netconn_listen_with_backlog() fails.
Fixes: 44e1a2d8e2 ("define tcp_backlog_set() as dummy-define when backlog feature is disable")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>
MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
lwipopts.h, if one of it is set to 0 we got build error due to unused variable.
Fix unused variable build error when MEMP_OVERFLOW_CHECK >= 1 &&
(MEMP_SANITY_REGION_BEFORE == 0 || MEMP_SANITY_REGION_AFTER == 0).
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>
There is only one caller using memp_overflow_init(), and at that context
calling memp_overflow_init_element() actually simplifes the code.
Thus remove memp_overflow_init() function.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>
Use LWIP_MEM_ALIGN() in memp_overflow_init() to get alignment address for memp.
This fixes assertion in memp_overflow_check_element_overflow when
MEMP_OVERFLOW_CHECK is set.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Fix below build error.
../../../../../lwip/src/core/memp.c: In function ‘memp_free’:
../../../../../lwip/src/core/memp.c:490:31: error: request for member ‘tab’ in something not a structure or union
old_first = memp_pools[type].tab;
^
../../Common.mk:94: recipe for target 'memp.o' failed
make: *** [memp.o] Error 1
Fixes: de9054cb7a ("memp: cleaned up MEMP_MEM_MALLOC")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
