files.c writes initial contents to game state files with fixed size.
Necessary for setting up invariants, such as struct sctstr members
sct_x, sct_y matching sct_uid.
Do that from the oninit() callback, so ef_blank() sets up invariants
correctly. Since ef_blank() isn't used for these files right now,
this isn't a bug fix, just cleanup.
New struct empfile member nent replaces ef_open() parameter nelt.
Cleaner, because the expected size is a property of the file, not of
how it's used. Also fixes empdump to check file sizes.
Complication: with EFF_CREATE, ef_open() creates an empty file, to be
extended to the correct size. Callers passed nelt argument -1 along
with EFF_CREATE, to make ef_open() accept the empty file. Can't do
the same for empfile member nent. Instead, make ef_open() not check
the (zero) size then.
Replaces commit 5750107b, v4.3.15.
Why upgrade? I'm not a lawyer, but here's my take on the differences
to version 2:
* Software patents: better protection against abuse of patents to
prevent users from exercising the rights under the GPL. I doubt
we'll get hit with a patent suit, but it's a good move just on
general principles.
* License compatibility: compatible with more free licenses, i.e. can
"steal" more free software for use in Empire. I don't expect to steal
much, but it's nice to have the option.
* Definition of "source code": modernization of some details for today's
networked world, to make it easier to distribute the software. Not
really relevant to us now, as we normally distribute full source code.
* Tivoization: this is about putting GPL-licensed software in hardware,
then make the hardware refuse to run modified software. "Neat" trick
to effectively deny its users their rights under the GPL. Abuse was
"pioneered" by TiVo (popular digital video recorders). GPLv3 forbids
it. Unlikely to become a problem for us.
* Internationalization: more careful wording, to harden the license
outside the US. The lawyers tell us it better be done that way.
* License violations: friendlier way to deal with license violations.
This has come out of past experience enforcing the GPL.
* Additional permissions: Probably not relevant to us.
Also include myself in the list of principal authors.
fgets() fails on read error or EOF. When it fails, it doesn't touch
the buffer. Since files didn't check its return value, it read an
uninitialized character from the buffer. If that happened to be 'y'
or 'Y', it happily clobbered the game.
This oopses on output dependency violations, e.g. two threads doing a
read-modify-write without synchronization, or the one thread nesting
several read-modify-writes. Such bugs are difficult to spot, and tend
to be abusable. I figure we have quite a few of them.
New struct emptypedstr member seqno. Make sure all members of unit
empobj_storage share it. Initialize it in files: main() and
file_sct_init(). Set it in ef_blank() and new ef_set_uid() by calling
new get_seqno(). Use ef_set_uid() when copying objects: swaps(),
doland(), doship(), doplane(), dounit(), delete_old_news(). Step it
in ef_write() by calling new new_seqno().
Factor do_read() out of fillcache() to make it available for
get_seqno().
Commit f33b96b1 (v4.3.12) made files again set timestamps. That was
intentionally suppressed in commit 990eb46b (v4.3.10), because it
facilitates attacks against the PRNG. Commit 8f98e53a (v4.3.0) had
added it as a feature.
Fix by making files's main() pass new flag EFF_NOTIME to ef_open().
Implement the flag in do_write().
Certain tables have a fixed size depending on configuration: EF_SECTOR
has WORLD_SZ() elements, EF_NATION, EF_MAP and EF_BMAP have MAXNOC
elements, and EF_REALM has MAXNOC * MAXNOR elements. Bad things
happen if the files backing them are shorter.
Pass expected size to ef_open(), and make it fail when the actual size
differs.
Make sure all members of unit empobj_storage share uid in addition to
ef_type.
Add matching uid member to struct gamestr, struct natstr and struct
sctstr, and set them.
Swap struct empobj members uid and own to make that easier, and update
struct comstr, struct lndstr, struct lonstr, struct loststr, struct
nwsstr, struct nukstr, struct plnstr, struct realmstr, struct shpstr,
struct trdstr, struct trtstr accordingly.
Note that the uid isn't properly set for struct nwsstr, struct lonstr,
struct trdstr, struct comstr and struct loststr. To be fixed.
Split ef_init() into two functions: empfile_init() for initialization,
and empfile_fixup() to fix it up for configuration. Put them next to
empfile[]. Move the call to empfile_init() from behind emp_config()
to before it.
sector and realm timestamps to current time. It's not useful, and it
facilitates attacks against the PRNG. This backs out fairland.c
rev. 1.27 and files.c rev. 1.31 and partly backs out files.c
rev. 1.38.
(isok, ef_init, bmaps_intersect, bp_init, player_accept)
(finish_sects, main): Use it.
(bp_neighbors, bp_lbcost, pathcost): Use XYOFFSET(). No
functional change.
(lndstr, plnstr, sctstr, shpstr): Change timestamp members lnd_access,
pln_access, sct_access, shp_access from real time (time_t) to ETUs
within a turn (short).
(land_ca, plane_ca, sect_ca, ship_ca): Update accordingly.
(build_ship, build_land, build_bridge, build_plane, build_tower)
(explore, check_trade, bsanct, takeover, takeover_ship)
(takeover_land): Use game_tick_to_now() instead of time() to update
the timestamp. Change check_trade(), takeover_ship(), takeover_land()
to do that only when MOB_ACCESS is enabled, for consistency.
(lupgr, supgr, pupgr, takeover_ship): Don't touch the timestamp where
mobility isn't touched either.
(sct_do_upd_mob, shp_do_upd_mob, lnd_do_upd_mob, pln_do_upd_mob): Use
game_tick_to_now() instead of increase_mob() to compute ETUs since
the timestamp and update the timestamp. Closes#1012699.
(increase_mob): Remove.
(mob_sect, mob_ship, mob_land, mob_plane): sct_do_upd_mob() & friends
no longer do the right thing at the update. Use game_reset_tick() and
pass its result directly to do_mob_sect() & friends. This is only
correct when argument is etu_per_update, which it always is. Remove
parameter. Callers changed.
(do_mob_sect, do_mob_ship, do_mob_land, do_mob_plane): Oops on
negative argument.
(mob_acc_globals, timestampfil, mobupdate, updating_mob)
(update_all_mob, timestamp_fixing, update_timestamps, mobility_check):
The mobupdate command was important to let deities manually
synchronize mobility updating with updates. That's no longer needed.
The code behind it is somewhat hairy and ugly, and updating it to work
with the Empire clock is just not worth it. Remove. Users changed.
(player_coms): Update accordingly.
(upda): Remove display of mobility updating state.
(mobility_init): No need to fix up mobility on startup, as the Empire
clock runs normally even when the server is down. Remove. Caller
changed.
(gamestr, EF_GAME, game_ca): New.
(empfile): Declare the table.
(ef_open_srv, ef_close_srv): Open and close it.
(main): Create it.
(empobj_storage): New member game.
(EF_DYNMAX): New.
(EF_IS_GAME_STATE): Use it.
other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
