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)
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.
```
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.
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.
Implement DHCPv6 option to exchange information about the Fully
Qualified Domain Name (FQDN) according to RFC 4704.
The RFC 4704 describes two models of operations in section 3,
currently only the second model is supported (DHCPv6 server
updates both the AAAA and the PTR RRs).
The existing DHCP Section Options SendHostname and Hostname are
sent as FQDN to the server. According to section 4.2 sending
only parts of its FQDN is allowed.
Fixes#4682.
ISO/IEC 9899:1999 §7.21.1/2 says:
Where an argument declared as size_t n specifies the length of the array
for a function, n can have the value zero on a call to that
function. Unless explicitly stated otherwise in the description of a
particular function in this subclause, pointer arguments on such a call
shall still have valid values, as described in 7.1.4.
In base64_append_width memcpy was called as memcpy(x, NULL, 0). GCC 4.9
started making use of this and assumes This worked fine under -O0, but
does something strange under -O3.
This patch fixes a bug in base64_append_width(), fixes a possible bug in
journal_file_append_entry_internal(), and makes use of the new function
to simplify the code in other places.
libsystemd-network provides the public function
sd_dhcp6_client_set_request_option() to enable the request of a given
DHCP option. However the enum defining such options is defined in the
internal header dhcp6-protocol.h. Move the enum definition to the
public header sd-dhcp6-client.h and properly namespace values.
The new dns_label_escape() call now operates on a buffer passed in,
similar to dns_label_unescape(). This should make decoding a bit faster,
and nicer.
strv_extend() does not consume the passed entry, hence, we must properly
free it. Furthermore, we should *not* use strv_consume() as we do greedy
allocations on 'ret'; and greedy-allocations should only be used for short
lived objects or caches.
Fix the domainname parser to properly free temporary storage when done.
Add a helper function containing a modified version of dns_packet_read_name()
that does not use DnsPacket to extract a string array of domain names from
the provided option data. The domain names are stored uncompressed as defined
in Section 8. of RFC 3315.
With this change the DHCP6_OPTION_IAADDR_LEN define can be removed in
favor of using sizeof(). Using the name of the struct and sizeof()
makes it clearer how much and what data is being copied from the
DHCPv6 message.
Add a Rapid Commit option to Solicit messages and expect a Reply to
be received instead of an Advertise. When receiving a DHCPv6 message
from the server in state Solicit, continue testing whether the
message is a Reply. Ease up the message type checking, it's not fatal
if the message is of a wrong type.
Add helper functions to set/get the rapid commit of a lease. See
RFC 3315, sections 17., 17.1.2., 17.1.4. and 18.1.8.
Add functionality to parse DHCPv6 Identity Association for
Non-temporary (IA_NA) and Temporary Addresses (IA_TA) options.
Both of them contain one or more IA Address (IAADDR) options
and optinally a status code option. Only the IA_NA option
contains lease lifetimes. See RFC 3315, sections 22.4., 22.5.,
22.6., 22.13. and appendix B. for details. If the lease
timeouts are not set, use the ones recommended for servers in
section 22.4.
Factor out common code in the form of an option header parsing
helper function.
Add option appending and parsing. DHCPv6 options are not aligned, thus
the option handling code must be able to handle options starting at
any byte boundary.
Add a test case for the basic option handling.
Lennart Poettering