If LWIP_CALLBACK_API is not defined, but TCP_LISTEN_BACKLOG is, then
the LWIP_EVENT_ACCEPT TCP event may be triggered for closed listening
sockets. This case is just as disastrous for the event API as it is
for the callback API, as there is no way for the event hook to tell
whether the listening PCB is still around. Add the same protection
against this case for TCP_LISTEN_BACKLOG as was already in place for
LWIP_CALLBACK_API.
Also remove one NULL check for LWIP_CALLBACK_API that had already
become redundant for all callers, making the TCP_EVENT_ACCEPT code
for that callback wrapper more in line with the rest of the wrappers.
This commit introduces a sockets_priv.h header for socket API internal
implementations intended to be used by sockets API C files, but not
applications
This commit moves struct lwip_setgetsockopt_data to the private header
because this is not part of the public sockets API, but needs to be
shared between sockets.c and memp.c
This header lays ground work for sharing other internal sockets types
/macros between API files (sockets.c and if_api.c)
Previously, on netifs with unrestricted MTUs (typically loopback
interfaces), it was possible to give a packet to the UDP/RAW API
calls that is so large that when prepending headers, the pbuf's
tot_len field would overflow. This could easily result in
undesirable behavior at lower layers, e.g. a crash when copying
the packet for later delivery.
This patch models such overflows as memory allocation errors, thus
resulting in clean failures. Checks have to be added in multiple
places to cover (hopefully) all cases.
Having the variable namining ret for a pointer makes the code looks odd,
ret looks like a value variable. Rename ret to pcb.
Also simplify the code in the do {} while() loop.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Couple of more cleanups for task #14314 involving includes:
1) if.h name should match if_api.c due to LwIP convention and history.
Standard if.h include can be used with compatibility header in
posix/net/if.h
2) API header (if.h) should not be included in core code. This include
has been eliminated by moving the definition of IF_NAMESIZE to
netif.h as NETIF_NAMESIZE. This is now the canonical definition
and IF_NAMESIZE just maps to it to provide the standard type
Now that tcp_connect() always determines the outgoing netif with a
route lookup, we can compute the effective MSS without doing the same
route lookup again. The outgoing netif is already known from one
other location that computes the MSS, so we can eliminate a redundant
route lookup there too. Reduce some macro clutter as a side effect.
This patch adds full support for IPv6 address scopes, thereby aiming
to be compliant with IPv6 standards in general and RFC 4007 in
particular. The high-level summary is that link-local addresses are
now meaningful only in the context of their own link, guaranteeing
full isolation between links (and their addresses) in this respect.
This isolation even allows multiple interfaces to have the same
link-local addresses locally assigned.
The implementation achieves this by extending the lwIP IPv6 address
structure with a zone field that, for addresses that have a scope,
carries the scope's zone in which that address has meaning. The zone
maps to one or more interfaces. By default, lwIP uses a policy that
provides a 1:1 mapping between links and interfaces, and considers
all other addresses unscoped, corresponding to the default policy
sketched in RFC 4007 Sec. 6. The implementation allows for replacing
the default policy with a custom policy if desired, though.
The lwIP core implementation has been changed to provide somewhat of
a balance between correctness and efficiency on on side, and backward
compatibility on the other. In particular, while the application would
ideally always provide a zone for a scoped address, putting this in as
a requirement would likely break many applications. Instead, the API
accepts both "properly zoned" IPv6 addresses and addresses that, while
scoped, "lack" a zone. lwIP will try to add a zone as soon as possible
for efficiency reasons, in particular from TCP/UDP/RAW PCB bind and
connect calls, but this may fail, and sendto calls may bypass that
anyway. Ultimately, a zone is always added when an IP packet is sent
when needed, because the link-layer lwIP code (and ND6 in particualar)
requires that all addresses be properly zoned for correctness: for
example, to provide isolation between links in the ND6 destination
cache. All this applies to packet output only, because on packet
input, all scoped addresses will be given a zone automatically.
It is also worth remarking that on output, no attempt is made to stop
outgoing packets with addresses for a zone not matching the outgoing
interface. However, unless the application explicitly provides
addresses that will result in such zone violations, the core API
implementation (and the IPv6 routing algorithm in particular) itself
will never take decisions that result in zone violations itself.
This patch adds a new header file, ip6_zone.h, which contains comments
that explain several implementation aspects in a bit more detail.
For now, it is possible to disable scope support by changing the new
LWIP_IPV6_SCOPES configuration option. For users of the core API, it
is important to note that scoped addresses that are locally assigned
to a netif must always have a zone set; the standard netif address
assignment functions always do this on behalf of the caller, though.
Also, core API users will want to enable LWIP_IPV6_SCOPES_DEBUG at
least initially when upgrading, to ensure that all addresses are
properly initialized.
The tests were in to catch user errors, but they seem to get in the way of application programming :-)
The checks in *_send() remain active to catch when PCB source and destination address types do not match
This commit cleans up the remaining instance of global variable
"index" shadowing caused by using local variables and function
parameters named "index"
These were introduced in the recent interface index API commits
Adjusts assert logic from 9c80a66253
to allow for a netif driver's init callback to manually override
the number. When the init function is taking care of the unique
assignment, the assert simply checks that a valid number was provided
This commit adds an LWIP_ASSERT to detect when netif_num overflows and
we no longer have unique numbers per netif. Unique netif numbers are
needed to support interface indexes (task #14314)
The only cases where this could occur are with a deployment that attempts
to use the maximum 256 netifs at the same time or where netifs are being
constantly adding and removed. Neither of these use cases fit the
lightweight goals of LwIP
See discussion in task #14314 for more details
- Code duplication with etharp_raw()
- No great effect on perfomance
- May make reworking PBUF handling code more complicated (see bug #49914)
- The check for p->type == PBUF_REF is a strange special case, too
- Simon also voted to remove it
../../../../lwip/src/core/ipv6/ip6_frag.c: In function ‘ip6_reass’:
../../../../lwip/src/core/ipv6/ip6_frag.c:567:7: error: ISO C90 forbids mixed declarations and code [-Werror=pedantic]
Eliminate ETHADDR32_COPY macro - it cannot be used in ETH_PAD_SIZE case. I could have kept it by defining it to ETHADDR16_COPY in case of ETH_PAD_SIZE, but I did not consider it worth another #ifdef mess.
Fix below compile error:
../../../../lwip/src/core/ipv6/ip6_frag.c: In function ‘ip6_reass’:
../../../../lwip/src/core/ipv6/ip6_frag.c:533:20: error: declaration of ‘next_pbuf’ shadows a previous local [-Werror=shadow]
struct pbuf* next_pbuf = iprh->next_pbuf;
^~~~~~~~~
../../../../lwip/src/core/ipv6/ip6_frag.c:272:20: note: shadowed declaration is here
struct pbuf *q, *next_pbuf;
^~~~~~~~~
cc1: all warnings being treated as errors
../Common.mk:93: recipe for target 'ip6_frag.o' failed
make: *** [ip6_frag.o] Error 1
Fixes: 7cedf7ae71 ("IPv6: fragment reassembly fixes")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
This patch aims to fix three closely related issues.
o The implementation of IPV6_FRAG_COPYHEADER was fundamentally
incompatible with the presence of extension headers between the
IPv6 header and the Fragment Header. This patch changes the
implementation to support such extension headers as well, with
pretty much the same memory requirements. As a result, we can
remove the check that prevented such packets from being reassembled
in all cases, even with IPV6_FRAG_COPYHEADER off.
o Given that temporary data is stored in the Fragment Header of
packets saved for the purpose of reassembly, but ICMPv6 "Fragment
Reassembly Time Exceeded" packets contain part of the original
packet, such ICMPv6 packets could actually end up containing part
of the temporary data, which may even include a pointer value. The
ICMPv6 packet should contain the original, unchanged packet, so
save the original header data before overwriting it even if
IPV6_FRAG_COPYHEADER is disabled. This does add some extra memory
consumption.
o Previously, the reassembly would leave the fragment header in the
reassembled packet, which is not permitted by RFC 2460 and prevents
reassembly of particularly large packets (close to 65535 bytes
after reassembly). This patch gets rid of the fragment header. It
does require an implementation of memmove() for that purpose.
Note that this patch aims to improve correctness. Future changes
might restore some of the previous functionality in order to regain
optimal performance for certain cases (at the cost of more code).
As per RFC requirements, upon removing a router from the default
router list, remove any entries pointing to it from the destination
cache. While here, synchronize timing out entries in the default
router list with the rest of the timer code.
When removing a netif, clear the destination cache altogether
in order to prevent more general inconsistency. When this happens,
the entries for other netifs will have to be rebuilt, but removing
netifs should be sufficiently rare that this is not worth optimizing.
The current ND implementation does not yet implement the most basic
required ('MUST') checks for message validation and generation.
- implement some of the required checks for message validation;
- document the remaining missing message validation checks;
- hardcode the hop limit of Neighbor Discovery messages rather than
having it depend on lwIP configuration which, if changed, would
cause all of ND to cease working.
The introduction of address lifetimes also means that lwIP correctly
supports transitions between PREFERRED and DEPRECATED address states,
and that means that the source address selection must be changed to
take this into account. Adding this feature to the previous algorithm
would have resulted in a mess, so this patch rewrites the algorithm to
stay close to the rules described in RFC 6724 (formerly 3484) Sec. 5.
This yields the following changes:
- Rule 2 ("prefer appropriate scope") is now fully implemented, most
importantly allowing larger-scope addresses to be picked if no
smaller-scope addresses are available (e.g., a global address may
now be used to connect to a unique-local address);
- Rule 3 ("avoid deprecated addresses") is now also fully implemented;
- unknown-scope addresses are also supported, with lowest priority;
- the link between the prescribed rules and the actual algorithm is
made much more explicit, hopefully allowing future improvements to
be made more easily.
For reasons explained in comments, one previous deviation from the RFC
on Rule 2 is retained for now.
As laid out in RFC 5942, the assumption that a dynamically assigned
(SLAAC/DHCPv6) address implies an on-link subnet, is wrong. lwIP does
currently make that assumption, routing packets according to local
address subnets rather than the on-link prefix list. The result is
that packets may not make it to their destination due to incorrect
routing decisions.
This patch changes the routing algorithms to be (more) compliant with
RFC 5942, by implementing the following new routing policies:
- all routing decisions check the on-link prefix list first, and
select a default router for off-link routing only if there is no
matching entry in the on-link prefix list;
- dynamically assigned addresses (from address autoconfiguration) are
considered /128 assignments, and thus, no routing decisions are taken
based on matches against their (/64) subnet anymore;
- more generally, all addresses that have a lifetime are considered
dynamically assigned and thus of size /128, which is the required
behavior for externally implemented SLAAC clients and DHCPv6;
- statically assigned (i.e., manually configured) addresses are still
considered /64 assignments, and thus, their associated subnet is
considered for routing decisions, in order to behave as generally
expected by end users and to retain backward compatibility;
- the link-local address in IPv6 address slot #0 is considered static
and thus has no lifetime and an implied /64 subnet, although link-
local routing is currently always handled separately anyway.
IPv6 source address selection is kept as is, as the subnet tests in
the algorithm serve as poor man's longest-common-prefix equivalent
there (RFC 6724 Sec. 5, Rule 8).
