diff options
Diffstat (limited to 'src/l4dreset.c')
| -rw-r--r-- | src/l4dreset.c | 39 |
1 files changed, 15 insertions, 24 deletions
diff --git a/src/l4dreset.c b/src/l4dreset.c index 4bffa3c..2245a16 100644 --- a/src/l4dreset.c +++ b/src/l4dreset.c @@ -44,7 +44,7 @@ static int off_callerrecords = -1; static int off_voteissues; // Note: the vote callers vector contains these as elements. We don't currently -// do anything with the structure, but keeping it here for reference. +// do anything with the structure, but we're keeping it here for reference. /*struct CallerRecord { u32 steamid_trunc; float last_time; @@ -78,8 +78,8 @@ static void reset(void) { // reset the vote cooldowns if possible (will skip L4D1). only necessary on // versions >2045 and on map 1, but it's easiest to do unconditionally if (off_callerrecords != -1) { - // Basically equivalent to CUtlVector::RemoveAll. The elements have no - // destructors to call. The resulting state is as if nobody has voted. + // This is equivalent to CUtlVector::RemoveAll() as there's no + // destructors to call. The result as is if nobody had ever voted. struct CUtlVector *recordvector = mem_offset(*votecontroller, off_callerrecords); recordvector->sz = 0; @@ -116,8 +116,7 @@ DEF_CCMD_HERE_UNREG(sst_l4d_quickreset, PREINIT { return GAMETYPE_MATCHES(L4D); } -// This finds the g_voteController variable using the listissues callback, and -// returns a pointer to the rest of the bytes for find_voteissues() below +// Note: this returns a pointer to subsequent bytes for find_voteissues() below static inline const uchar *find_votecontroller(con_cmdcbv1 listissues_cb) { const uchar *insns = (const uchar *)listissues_cb; #ifdef _WIN32 @@ -136,8 +135,6 @@ static inline const uchar *find_votecontroller(con_cmdcbv1 listissues_cb) { return 0; } -// This finds ListIssues() using the instruction pointer returned by -// find_votecontroller() above, and then uses that to find the vote issue list. static inline bool find_voteissues(const uchar *insns) { #ifdef _WIN32 for (const uchar *p = insns; p - insns < 16;) { @@ -150,10 +147,9 @@ static inline bool find_voteissues(const uchar *insns) { } return false; ok: for (const uchar *p = insns; p - insns < 96;) { - // There's a virtual call on each actual CVoteIssue in the loop over the - // list. That entails putting the issue pointer in ECX, which involves - // loading that pointer from the vector, which exists at an offset from - // `this`, meaning we can find the offset from the mov into ECX. + // The loop in ListIssues() calls a member function on each CVoteIssue. + // Each pointer is loaded from a CUtlVector at an offset from `this`, so + // we can find that offset from the mov into ECX. if (p[0] == X86_MOVRMW && (p[1] & 0xF8) == 0x88) { int off = mem_loadoffset(p + 2); if (off > 800) { // sanity check: offset is always fairly high @@ -161,9 +157,8 @@ ok: for (const uchar *p = insns; p - insns < 96;) { return true; } } - // Further complication: at least in 2045 there's a short jmp over some - // invalid instruction bytes. I guess there's no reason to ever expect - // something interesting after an unconditional jmp, so just follow it. + // Complication: at least 2045 has a short jmp over some garbage bytes. + // Follow that jmp since there's nothing interesting before the target. if (p[0] == X86_JMPI8) { p += 2 + ((s8 *)p)[1]; continue; @@ -176,15 +171,12 @@ ok: for (const uchar *p = insns; p - insns < 96;) { return false; } -// This finds the caller record vector using a pointer to the -// CVoteController::Spawn function static inline bool find_votecallers(void *votectrlspawn) { #ifdef _WIN32 const uchar *insns = (const uchar *)votectrlspawn; for (const uchar *p = insns; p - insns < 64;) { - // Unsure what the member on this offset actually is (the game seems to - // want it to be set to 0 to allow votes to happen), but the vector we - // want seems to consistently be 8 bytes after whatever this is + // Unsure what this offset points at (it seems to have to be 0 for votes + // to happen), but the vector of interest always comes 8 bytes later. // "mov dword ptr [<reg> + off], 0", mod == 0b11 if (p[0] == X86_MOVMIW && (p[1] & 0xC0) == 0x80 && mem_load32(p + 6) == 0) { @@ -215,12 +207,11 @@ INIT { errmsg_errorx("couldn't find vote issues list offset\n"); return false; } - // only bother with vote cooldown stuff for L4D2, since all versions of L4D1 - // have unlimited votes anyway. NOTE: assuming L4D2 always has Spawn in - // gamedata (which has no reason to stop being true...) + // Only try cooldown stuff for L4D2, since L4D1 always had unlimited votes. + // NOTE: assuming L4D2 always has Spawn in gamedata (why wouldn't it?) if (GAMETYPE_MATCHES(L4D2)) { - // g_voteController may have not been initialized yet so we get the - // vtable from the ent factory + // g_voteController is invalid if not running a server so get the + // vtable by inspecting the ent factory code instead const struct CEntityFactory *factory = ent_getfactory("vote_controller"); if (!factory) { errmsg_errorx("couldn't find vote controller entity factory"); |