tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.

libsystemd-network: split icm6-util.[ch] out of dhcp6 code

dhcp6-option: Add helper function for uncompressed domain names 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.

dhcp6-option: Add helper function for fetching IPv6 addresses Add a helper function that extracts a block of IPv6 addresses from the provided option data.

log: rearrange log function naming - Rename log_meta() → log_internal(), to follow naming scheme of most other log functions that are usually invoked through macros, but never directly. - Rename log_info_object() to log_object_info(), simply because the object should be before any other parameters, to follow OO-style programming style.

log: add an "error" parameter to all low-level logging calls and intrdouce log_error_errno() as log calls that take error numbers This change has two benefits: - The format string %m will now resolve to the specified error (or to errno if the specified error is 0. This allows getting rid of a ton of strerror() invocations, a function that is not thread-safe. - The specified error can be passed to the journal in the ERRNO= field. Now of course, we just need somebody to convert all cases of this: log_error("Something happened: %s", strerror(-r)); into thus: log_error_errno(-r, "Something happened: %m");

sd-dhcp6-lease: Name the structure containing IAADDR data 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.

sd-dhcp6-client: Receive and parse Advertise messages When receiving DHCPv6 messages, discard the ones that are not meant for DHCPv6 clients and verify the transaction id. Once that is done, process the Advertise message and select the Advertise with the highest preference. Create a separate function for lease information parsing so that it can be reused in other parts of the protocol. Verify both DUID and IAID in the received message and store other necessary information with the lease structure.

sd-dhcp6-client: Add IA Address option parsing 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.

sd-dhcp6-client: Add DHCPv6 Solicit message creation and sending Implement the initial functionality used for creating a DHCPv6 Solicit message containing the needed options and send it to the DHCPv6 broadcast address. Increase the sent message count and ensure that the Solicit Initial Retransmission Time is strictly greater than the Solicitation IRT as described in RFC 3315, section 17.1.2.

sd-dhcp6-client: Add functions to bind to DHCPv6 UDP socket Add a function that creates a UDP socket bound to the given interface and optionally to an IPv6 address. Add another function that will send the DHCPv6 UDP packet to its destination. Using IPV6_PKTINFO in setsockopt to bind the IPv6 socket to an interface is documented in section 4. of RFC 3542, "Advanced Sockets Application Program Interface (API) for IPv6" Add a define for DHCPv6 Relay Agents and Servers multicast address as its not available elsewhere.

sd-dhcp6-client: Add basic DHCPv6 option handling 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.

sd-dhcp6-client: Add DHCPv6 IAID functionality Create structures describing Identity Association IDentifiers and IPv6 lease addresses. [tomegun: initialize the IAID when client is started. Base this off of the predictable udev names, if available, as these satisfy the requirement of the IAID, and base it off the mac addres otherwise, as that is the best we have.]

sd-icmp6-nd: Add Router Solicitation and Advertisement support Provide functions to bind the ICMPv6 socket to the approriate interface and set multicast sending and receiving according to RFC 3493, section 5.2. and RFC 3542, sections 3. and 3.3. Filter out all ICMPv6 messages except Router Advertisements for the socket in question according to RFC 3542, section 3.2. Send Router Solicitations to the all routers multicast group as described in RFC 4861, section 6. and act on the received Router Advertisments according to section 6.3.7. Implement a similar API for ICMPv6 handling as is done for DHCPv4 and DHCPv6.