This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
If we can't send a message this is no reason to completely abort the
event handler.
Issue identified by Nandor Han <nandor.han@ge.com>, Sebastian Reichel
<sebastian.reichel@collabora.co.uk>.
Replaces: #8525
The type is "ssize_t", not "int", let's be accurate about that, as these
types are different on some archs.
Given that we don't actually care about the return value reall, drop
the whole assignment, just check if negative.
This makes users can configure DHCPv4 client with ClientIdentifier=duid-only.
If set so, then DHCP client sends only DUID as the client identifier.
This may not be RFC compliant, but some setups require this.
Closes#7828.
Commit f11cba7479 ("libsystemd-network: fix unaligned loads (issue #7654)")
changed the way in which the MAC address is read to use native endiannes:
htobe32(*((uint32_t *)x) -> unaligned_read_ne32(x)
This is wrong because loads done with BPF_LD + BPF_ABS are big-endian, as it
can be seen for the ethertype and arp-operation loads above in the
filter. Also, the same commit changed:
htobe32(*((unsigned int *)x) -> unaligned_read_be32(x)
in _bind_raw_socket(), which is the correct form.
The commit broke IPv4LL in presence of loops, as the sender now considers its
own packets as conflicting.
Fixes: f11cba7479
Ever since the initial implementation in 631bbe7129,
client_parse_message() was supposed to check that the message contains exactly
one serverid. The check that no more than one is given was implemented
correctly, but the check that at least one is given was not. Simplify the whole
thing by making dhcp6_lease_get_serverid() return an error if the id is not
set, and do not require the arguments to be present if the contents of the id
are not needed.
Technically, `data` is a sequence of bytes without a trailing zero,
so the use of `memcmp` seems to be logical here. Besides, this helps get
around a bug that makes `asan` report the false positive mentioned in
#8052.
Closes#8052.
The DHCPv6 client will set its state to DHCP6_STATE_STOPPED if
an error occurs or when receiving an Information Reply DHCPv6
message. Once in DHCP6_STATE_STOPPED, the DHCPv6 client needs
to be restarted by calling sd_dhcp6_client_start().
As of pull request #7796 client_reset() no longer closes the
network socket, thus a call to sd_dhcp6_client_start() needs to
check whether the file descriptor already exists in order not to
create a new one. Likewise, a call to sd_dhcp6_client_unref()
must now close the network socket as client_reset() is not
closing it.
Reported by asavah and Yu Watanabe.
The DHCPv6 client can obtain configuration parameters from a
DHCPv6 server through a rapid two-message exchange solicit and reply).
When the rapid commit option is enabled by both the DHCPv6 client and
the DHCPv6 server, the two-message exchange is used, rather than the default
four-method exchange (solicit, advertise, request, and reply). The two-message
exchange provides faster client configuration and is beneficial in environments
in which networks are under a heavy load.
Closes#5845
When the DHCP server returns both a Classless Static Routes
option and a Static Routes option, the DHCP client MUST ignore the
Static Routes option.
Closes#7792
This fixes the following warnings:
```
[194/1521] Compiling C object 'src/libsystemd-network/systemd-network@sta/dhcp6-option.c.o'.
../../git/systemd/src/libsystemd-network/dhcp6-option.c:110:25: warning: taking address of packed member 'id' of class or structure 'ia_na' may result in an unaligned pointer value [-Waddress-of-packed-member]
iaid = &ia->ia_na.id;
^~~~~~~~~~~~
../../git/systemd/src/libsystemd-network/dhcp6-option.c:115:25: warning: taking address of packed member 'id' of class or structure 'ia_ta' may result in an unaligned pointer value [-Waddress-of-packed-member]
iaid = &ia->ia_ta.id;
^~~~~~~~~~~~
2 warnings generated.
```
The slightly modified review comments say that "...in theory
offsetof(DHCP6Option, data) is nicer than sizeof(DHCP6Option)
because the former removes alignment artifacts. In this
specific case there are no alignment whitespaces hence it's
fine, but out of a matter of principle offsetof() is preferred
over sizeof() in cases like this..."
Calling dhcp6_option_parse_address() will always return a value
< 0 on error even though lt_valid remains unset. This is more
than valgrind can safely detect, but let's fix the valgrind
nitpick anyway.
While fixing, use UINT32_MAX instead of ~0 on the same line.
log.h really should only include the bare minimum of other headers, as
it is really pulled into pretty much everything else and already in
itself one of the most basic pieces of code we have.
Let's hence drop inclusion of:
1. sd-id128.h because it's entirely unneeded in current log.h
2. errno.h, dito.
3. sys/signalfd.h which we can replace by a simple struct forward
declaration
4. process-util.h which was needed for getpid_cached() which we now hide
in a funciton log_emergency_level() instead, which nicely abstracts
the details away.
5. sys/socket.h which was needed for struct iovec, but a simple struct
forward declaration suffices for that too.
Ultimately this actually makes our source tree larger (since users of
the functionality above must now include it themselves, log.h won't do
that for them), but I think it helps to untangle our web of includes a
tiny bit.
(Background: I'd like to isolate the generic bits of src/basic/ enough
so that we can do a git submodule import into casync for it)
Both netinet/icmp6.h and linux/in6.h will define struct in6_addr, and in
user space we want to use the netinet/icmp6.h variant.
Fixes build problem:
In file included from src/libsystemd-network/sd-radv.c:23:0:
/home/hegtvedt/work/os/product/sunrise/root/_build/v2/include/linux/in6.h:30:8:
error: redefinition of 'struct in6_addr'
As DHCPv6 leases may expire at some point, the delegated prefixes
have to be removed. Add a prefix removal function to the Router
Advertisement handling code.
Add a boolean that indicates whether the prefixes will always exist
or if they will time out after the assigned valid lifetime. In the
latter case calculate the expiry times for both preferred and valid
lifetimes for the prefixes, and decrease the remaining lifetimes
each time when a Router Advertisement is sent.
Should the prefix be updated, re-calculate the prefix lifetime. When
updating, update the existing entry, if any, with the lifetimes of
the added entry as the existing entry has its lifetimes set
according to its previously calculated expiry times.
Compute one set of minimum lifetimes for T1 and T2, i.e. the smaller
ones assigned to IA NA and IA PD. The lifetimes should be the same,
see RFC 7550 for details.
Parse IA PD options and the prefixes in one or more PD Prefix
options. As the PD option contains identical data as the IA NA
option, re-use the same general data structures and sub-option
parsing logic. Similar to IA NA addresses, PD and associated
prefixes are stored in the address list of the IA PD lease.
An IA sub-option Status code will affect the IA NA and IA PD
option in question and cause those options to be ignored. A
Status code option in an IA Address or IA PD Prefix option
affects only that IA Address or Prefix.
Factor out IA Address option parsing and fix it so that all conditions
are checked before a new address is allocated and added to the address
list. Note also that the IA Address option can contain a nested Status
option. If the status in anything else than zero, the DHCPv6 server is
communicating an error condition and the address cannot be used.
Status option nesting is clarified in RFC 7550, Section 4.1.
The IA Address option is included as a typedef so that the lifetimes
can be inspected before allocating a new address and the option length
needed is easily available.
Sanitize code for parsing DHCPv6 IA NA and TA options and their
nested Status options so that the options can be fully and
properly ignored should they not be conformant to the specification.
Do this by defining a proper DHCP6Option structure and sending that
structure to the parsing function. The parsing function will then
not manipulate either any option data pointers or their lengths in
order to iterate over the current option. Needless to say, this
affects a few files including the test program.
Close DHCPv6 client socket file descriptor when
sd_dhcp6_client_stop() is called and not when client_reset() is
called. If left in client_reset(), any internal temporary stopping
of the DHCPv6 client with client_stop() will call client_reset()
after which the DHCPv6 client will not be able to receive any further
DHCPv6 messages.
Similarly, client_start() needs to enable events for the DHCPv6
socket file descriptor since a call to client_stop() will call
client_reset() which will remove it from the main loop. Events should
be turned off when no DHCPv6 messages are expected.
This adds a simple condition/assert/match to the service manager, to
udev's .link handling and to networkd, for matching the kernel version
string.
In this version we only do fnmatch() based globbing, but we might want
to extend that to version comparisons later on, if we like, by slightly
extending the syntax with ">=", "<=", ">", "<" and "==" expressions.
Let's replace usage of fputc_unlocked() and friends by __fsetlocking(f,
FSETLOCKING_BYCALLER). This turns off locking for the entire FILE*,
instead of doing individual per-call decision whether to use normal
calls or _unlocked() calls.
This has various benefits:
1. It's easier to read and easier not to forget
2. It's more comprehensive, as fprintf() and friends are covered too
(as these functions have no _unlocked() counterpart)
3. Philosophically, it's a bit more correct, because it's more a
property of the file handle really whether we ever pass it on to another
thread, not of the operations we then apply to it.
This patch reworks all pieces of codes that so far used fxyz_unlocked()
calls to use __fsetlocking() instead. It also reworks all places that
use open_memstream(), i.e. use stdio FILE* for string manipulations.
Note that this in some way a revert of 4b61c87511.
Using strlen() to declare a buffer results in a variable-length array,
even if the compiler likely optimizes it to be a compile time constant.
When building with -Wvla, certain versions of gcc complain about such
buffers. Compiling with -Wvla has the advantage of preventing variably
length array, which defeat static asserts that are implemented by
declaring an array of negative length.
