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.

dhcp: make DHCP_OPTION_* enum public libsystemd-network provides the public function sd_dhcp_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 dhcp-protocol.h. Move the enum definition to the public header sd-dhcp-client.h and properly namespace values.

tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy GLIB has recently started to officially support the gcc cleanup attribute in its public API, hence let's do the same for our APIs. With this patch we'll define an xyz_unrefp() call for each public xyz_unref() call, to make it easy to use inside a __attribute__((cleanup())) expression. Then, all code is ported over to make use of this. The new calls are also documented in the man pages, with examples how to use them (well, I only added docs where the _unref() call itself already had docs, and the examples, only cover sd_bus_unrefp() and sd_event_unrefp()). This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we tend to call our destructors these days. Note that this defines no public macro that wraps gcc's attribute and makes it easier to use. While I think it's our duty in the library to make our stuff easy to use, I figure it's not our duty to make gcc's own features easy to use on its own. Most likely, client code which wants to make use of this should define its own: #define _cleanup_(function) __attribute__((cleanup(function))) Or similar, to make the gcc feature easier to use. Making this logic public has the benefit that we can remove three header files whose only purpose was to define these functions internally. See #2008.

sd-dhcp: parse error message in DECLINE or NAK If a client sends a DECLINE or a server sends a NAK, they can include a string with a message to explain the error. Parse this and print it at debug level.

libsystemd-network: clean up recv functions

siphash24: let siphash24_finalize() and siphash24() return the result directly Rather than passing a pointer to return the result, return it directly from the function calls. Also, return the result in native endianess, and let the callers care about the conversion. For hash tables and bloom filters, we don't care, but in order to keep MAC addresses and DHCP client IDs stable, we explicitly convert to LE.

siphash24: change result argument to uint64_t Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which enforce pointer alignment this fixes crashes when we previously cast an unaligned array to uint64_t*, and on others this should at least improve performance as the compiler now aligns these properly. This also simplifies the code in most cases by getting rid of typecasts. The only place which we can't change is struct duid's en.id, as that is _packed_ and public API, so we can't enforce alignment of the "id" field and have to use memcpy instead.

util-lib: split out allocation calls into alloc-util.[ch]

util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.

sd-*.h: clean up exported (or to-be-exported) header files Exported header files should not include internal headers. Fix that. Exported header files should not use the bool type. So far we opted to stick to C89 for exported headers, and hence use "int" for bools in them. Continue to do so. Exported header files should have #include lines for everything they use including inttypes.h and sys/types.h, so that they may be included in any order. Exported header files should have C++ guards, hence add them. Exported header files should not use gcc extensions like #pragma once, get rid of it.

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.

siphash24: unify API Make the API of the new helpers more similar to the old wrapper. In particular we now return the hash as a byte string to avoid any endianness problems.

hashmap: hash_funcs - make inputs unambiguous Make sure all variable-length inputs are properly terminated or that their length is encoded in some way. This avoids ambiguity of adjacent inputs. E.g., in case of a hash function taking two strings, compressing "ab" followed by "c" is now distinct from "a" followed by "bc".

hashmap: refactor hash_func All our hash functions are based on siphash24(), factor out siphash_init() and siphash24_finalize() and pass the siphash state to the hash functions rather than the hash key. This simplifies the hash functions, and in particular makes composition simpler as calling siphash24_compress() repeatedly on separate chunks of input has the same effect as first concatenating the input and then calling siphash23_compress() on the result.

tree-wide: do not shadow the global var timezone

sd-dhcp-server: simplify pool creation Merge sd_dhcp_server_set_address() and sd_dhcp_server_set_lease_pool() into sd_dhcp_server_configure_pool() as the behavior of the two former depends on the order they are called in. The flexibility is not needed, so let's just do this in one call.

sd-dhcp-server: improve predictability of leases Rather than having all clients attempt to get the same leases (starting at the beginning of the pool), make each client star at a random offset into the pool determined by their client id. This greatly increases the chances of a given client receiving the same IP address even though both the client and server have lost any lease information (and distinct server instances handing out the same leases).

dhcp,network: support emitting DNS/NTP server information from DHCP server For now, this is very simple and IP addresses have to be configured manually.

networkd: make DHCP lease timeouts configurable

dhcp: rename index to ifindex This avoids confusion what this is, in particular as libc knows an index() function.

dhcp: store client id as void*, since we dont know what it is

dhcp: properly handle error from ioctl()

dhcp: generic data should be void*, not uint8_t* If we handly arbitrary data we should use "void*" pointers, not "uint8_t*", how go intended C to be used.

network: s/user_data/userdata/ Everywhere else we call the generic user data pointer just "userdata", rather than "user_data". Let's do this here, too.

dhcp: stop using refcnt.h No need to invole atomic ops in single-threaded APIs, let's simplify this.

dhcp,network: implement RFC 4833 (DHCP Timezone option) This one is simply to add: encode the tzdata timezone in the DHCP options and optionally make use of it.

tree-wide: do not return error codes as bool

networkd: DHCP fix CID 1315105 CID 1315105: Resource leaks (RESOURCE_LEAK) /src/libsystemd-network/sd-dhcp-server.c: 800 in dhcp_server_handle_message() *** CID 1315105: Resource leaks (RESOURCE_LEAK) /src/libsystemd-network/sd-dhcp-server.c: 800 in

sd-event: make sure sd_event_now() cannot fail Previously, if the event loop never ran before sd_event_now() would fail. With this change it will instead fall back to invoking now(). This way, the function cannot fail anymore, except for programming error when invoking it with wrong parameters. This takes into account the fact that many callers did not handle the error condition correctly, and if the callers did, then they kept simply invoking now() as fall back on their own. Hence let's shorten the code using this call, and make things more robust, and let's just fall back to now() internally. Whether now() is used or the cache timestamp may still be detected via the return value of sd_event_now(). If > 0 is returned, then the fall back to now() was used, if == 0 is returned, then the cached value was returned. This patch also simplifies many of the invocations of sd_event_now(): the manual fall back to now() can be removed. Also, in cases where the call is invoked withing void functions we can now protect the invocation via assert_se(), acknowledging the fact that the call cannot fail anymore except for programming errors with the parameters. This change is inspired by #841.

util: introduce CMSG_FOREACH() macro and make use of it everywhere It's only marginally shorter then the usual for() loop, but certainly more readable.

fix gcc warnings about uninitialized variables like: src/shared/install.c: In function ‘unit_file_lookup_state’: src/shared/install.c:1861:16: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] return r < 0 ? r : state; ^ src/shared/install.c:1796:13: note: ‘r’ was declared here int r; ^

remove unused includes This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.

Revert "tree-wide: Always use recvmsg with MSG_CMSG_CLOEXEC" This reverts commit d6d810fbf8071f8510450dbacd1d083f37603656. It's apparently not OK to pass MSG_CMSG_CLOEXEC to recvmsg() of raw sockets.

tree-wide: Always use recvmsg with MSG_CMSG_CLOEXEC

treewide: correct typos and use consistent "MAC" spelling

sd-dhcp-client: support non-Ethernet hardware addresses Like Infiniband. See RFC 4390 section 2.1 for details on DHCP and Infiniband; chaddr is zeroed, hlen is set to 0, and htype is set to ARPHRD_INFINIBAND because IB hardware addresses are 20 bytes in length.

hashmap: introduce hash_ops to make struct Hashmap smaller It is redundant to store 'hash' and 'compare' function pointers in struct Hashmap separately. The functions always comprise a pair. Store a single pointer to struct hash_ops instead. systemd keeps hundreds of hashmaps, so this saves a little bit of memory.

sd-dhcp-server: linebreaks Don't overflow unnecessarily.

sd-dhcp-server: always send out ROUTER and SUBNET_MASK For now we simply take these values from the server's address.

sd-dhcp-server: avoid returning garbage value Force renewing with a pool size of 0 would return the uninitialized r.

sd-dhcp-server: check if r < 0

sd-dhcp-server: add forcerenew support

libsystemd-network: use CLOCK_BOOTTIME instead of CLOCK_MONOTONIC where possible The timeouts in the networking library (DHCP lease timeouts and similar) should not be affected by suspend. In the cases where CLOCK_BOOTTIME is not implemented, it is still safe to fallback to CLOCK_MONOTONIC, as the consumers of the library (i.e., networkd) _should_ renew the leases when coming out of suspend.

sd-dhcp-server: make gcc happy It complains about optoffset possibly being uninitialized. It is wrong, but let's just initialize it.

networkd/sd-dhcp-server: only start dhcp server when necessary

sd-dhcp-server: change default lease time form 1m to 1h The short lease was useful for testing, but in real-world usage it is pointless to keep leases this short. That said, the cost of lease renewal is really low, so we keep the lease still relatively short at one hour to not get into hard-to-hit problems with lease exhaustion etc.

sd-dhcp-server: fix broadcast of DHCP packets The destination IP address should be INADDR_BROADCAST, but was accidentally left as INADDR_ANY.

sd-dhcp-server: remove unused cleanup function Removes _cleanup_dhcp_lease_free_. While the automatic cleanup functions are great to have this one is never used and causes a warning in clang.

dhcp-server: simplify dhcp server unref call No need to use HASHMAP_ITERATE when we destruct all entries anyway.

sd-dhcp-server: fix a leak We must use free instead of dhcp_lease_free here to avoid freeing client_id.data.

sd-dhcp-server: add RELEASE support

sd-dhcp-server: add dummy DECLINE support

sd-dhcp-server: track bound leases Make sure we don't hand out the same IP twice. We still don't handle lease expiry.

sd-dhcp-server: add support for clients requesting lease lifetime

sd-dhcp-server: add basic NAK support

sd-dhcp-server: add basic REQUEST/ACK support

sd-dhcp-server: add basic DISCOVER/OFFER support

sd-dhcp-server: add support for sending messages

sd-dhcp-server: add support for setting the server address

sd-dhcp-server: bind to raw socket for sending We would like to use the UDP socket, but we cannot as we need to specify the MAC address manually.

sd-dhcp-server: add basic message parsing Parse the maximum message size the client can accept and the client id, falling back to sane defaults if they are not set.

sd-dhcp-server: add basic message handling and verification

sd-dhcp-server: bind to a given interface We will (at least at first), restrict our focus to running the server on at most one interface.

sd-dhcp-server: add basic functionality for starting/stopping server Bind to UDP socket and listen for messages, discarding anything we receive.

sd-dhcp-server: add basic functionality for creating/destroying server instance