qcsrc/server/anticheat.qc

   1 .float anticheat_jointime;
   2
   3 void mean_accumulate(entity e, .float a, .float c, float mean, float value, float weight)
   4 {
   5         if(weight == 0)
   6                 return;
   7         if(mean == 0)
   8                 e.a *= pow(value, weight);
   9         else
  10                 e.a += pow(value, mean) * weight;
  11         e.c += weight;
  12 }
  13
  14 float mean_evaluate(entity e, .float a, .float c, float mean)
  15 {
  16         if(e.c == 0)
  17                 return 0;
  18         if(mean == 0)
  19                 return pow(e.a, 1.0 / e.c);
  20         else
  21                 return pow(e.a / e.c, 1.0 / mean);
  22 }
  23
  24 #define MEAN_ACCUMULATE(prefix,v,w) mean_accumulate(self,prefix##_accumulator,prefix##_count,prefix##_mean,v,w)
  25 #define MEAN_EVALUATE(prefix) mean_evaluate(self,prefix##_accumulator,prefix##_count,prefix##_mean)
  26 #define MEAN_DECLARE(prefix,m) float prefix##_mean = m; .float prefix##_count, prefix##_accumulator
  27
  28 .float anticheat_fixangle_endtime;
  29
  30 float anticheat_div0_evade_evasion_delta;
  31 .float anticheat_div0_evade_offset;
  32 .vector anticheat_div0_evade_v_angle;
  33 .vector anticheat_div0_evade_forward_initial;
  34 MEAN_DECLARE(anticheat_div0_evade, 5);
  35
  36 .vector anticheat_div0_strafebot_movement_prev;
  37 MEAN_DECLARE(anticheat_div0_strafebot_old, 5);
  38
  39 .vector anticheat_div0_strafebot_forward_prev;
  40 MEAN_DECLARE(anticheat_div0_strafebot_new, 5);
  41
  42 // Snap-aim detection: we track the average angular speed of aiming over time, in "radians per second".
  43 // Signal: a high-power mean. Cheaters will have high "signal" here.
  44 // Noise: a low-power mean. Active/shivery players will have high "noise" here.
  45 // Note one can always artificially add noise - so very high values of both signal and noise need to be checked too.
  46 MEAN_DECLARE(anticheat_idle_snapaim_signal, 5);
  47 MEAN_DECLARE(anticheat_idle_snapaim_noise, 1);
  48
  49 // TEMP DEBUG STUFF.
  50 MEAN_DECLARE(anticheat_idle_snapaim_m2, 2);
  51 MEAN_DECLARE(anticheat_idle_snapaim_m3, 3);
  52 MEAN_DECLARE(anticheat_idle_snapaim_m4, 4);
  53 MEAN_DECLARE(anticheat_idle_snapaim_m7, 7);
  54 MEAN_DECLARE(anticheat_idle_snapaim_m10, 10);
  55
  56 .float anticheat_speedhack_offset;
  57 .float anticheat_speedhack_movetime, anticheat_speedhack_movetime_count, anticheat_speedhack_movetime_frac;
  58 MEAN_DECLARE(anticheat_speedhack, 5);
  59
  60 .float anticheat_speedhack_accu;
  61 .float anticheat_speedhack_lasttime;
  62 MEAN_DECLARE(anticheat_speedhack_m1, 1);
  63 MEAN_DECLARE(anticheat_speedhack_m2, 2);
  64 MEAN_DECLARE(anticheat_speedhack_m3, 3);
  65 MEAN_DECLARE(anticheat_speedhack_m4, 4);
  66 MEAN_DECLARE(anticheat_speedhack_m5, 5);
  67
  68 float movement_oddity(vector m0, vector m1)
  69 {
  70         float cosangle = normalize(m0) * normalize(m1);
  71         if(cosangle >= 0)
  72                 return 0;
  73         return 0.5 - 0.5 * cos(cosangle * cosangle * 4 * M_PI);
  74                 // returns 0 for: -1, -sqrt(0.5), 0 (angles that commonly happen with kbd)
  75 }
  76
  77 void anticheat_physics()
  78 {
  79         float f, wishspeed;
  80         vector wishvel;
  81
  82         // div0_evade -> SPECTATORS
  83         makevectors(self.v_angle);
  84         if(self.anticheat_div0_evade_offset == 0)
  85         {
  86                 f = fabs(anticheat_div0_evade_evasion_delta - floor(anticheat_div0_evade_evasion_delta) - 0.5) * 2; // triangle function
  87                 self.anticheat_div0_evade_offset = servertime + sys_frametime * (3 * f - 1);
  88                 self.anticheat_div0_evade_v_angle = self.v_angle;
  89                 self.anticheat_div0_evade_forward_initial = v_forward;
  90                 MEAN_ACCUMULATE(anticheat_div0_evade, 0, 1);
  91         }
  92         else
  93         {
  94                 if(time < self.anticheat_div0_evade_offset)
  95                         self.anticheat_div0_evade_v_angle = self.v_angle;
  96                 MEAN_ACCUMULATE(anticheat_div0_evade, 0.5 - 0.5 * (self.anticheat_div0_evade_forward_initial * v_forward), 1);
  97         }
  98
  99         MEAN_ACCUMULATE(anticheat_div0_strafebot_old, movement_oddity(self.movement, self.anticheat_div0_strafebot_movement_prev), 1);
 100         self.anticheat_div0_strafebot_movement_prev = self.movement;
 101
 102         // Note: this actually tries to detect snap-aim.
 103         if(vlen(self.anticheat_div0_strafebot_forward_prev) && time > self.anticheat_fixangle_endtime) {
 104                 float cosangle = self.anticheat_div0_strafebot_forward_prev * v_forward;
 105                 float angle = cosangle < -1 ? M_PI : cosangle > 1 ? 0 : acos(cosangle);
 106                 /*
 107                 if (angle >= 10 * M_PI / 180)
 108                         printf("SNAP %s: %f for %f, %f since fixangle\n", self.netname, angle * 180 / M_PI, cosangle, time - self.anticheat_fixangle_endtime);
 109                 */
 110                 MEAN_ACCUMULATE(anticheat_div0_strafebot_new, angle / M_PI, 1);
 111
 112                 if (autocvar_slowmo > 0) {
 113                         // Technically this is a NOP, as the engine should be ensuring
 114                         // this in the first place. Let's guard against dividing by
 115                         // zero anyway.
 116                         float dt = max(0.001, frametime) / autocvar_slowmo;
 117
 118                         float anglespeed = angle / dt;
 119                         MEAN_ACCUMULATE(anticheat_idle_snapaim_signal, anglespeed, dt);
 120                         MEAN_ACCUMULATE(anticheat_idle_snapaim_noise, anglespeed, dt);
 121                         MEAN_ACCUMULATE(anticheat_idle_snapaim_m2, anglespeed, dt);
 122                         MEAN_ACCUMULATE(anticheat_idle_snapaim_m3, anglespeed, dt);
 123                         MEAN_ACCUMULATE(anticheat_idle_snapaim_m4, anglespeed, dt);
 124                         MEAN_ACCUMULATE(anticheat_idle_snapaim_m7, anglespeed, dt);
 125                         MEAN_ACCUMULATE(anticheat_idle_snapaim_m10, anglespeed, dt);
 126                 }
 127         }
 128         self.anticheat_div0_strafebot_forward_prev = v_forward;
 129
 130         // generic speedhack detection: correlate anticheat_speedhack_movetime (UPDATED BEFORE THIS) and server time
 131         self.anticheat_speedhack_movetime_frac += frametime;
 132         f = floor(self.anticheat_speedhack_movetime_frac);
 133         self.anticheat_speedhack_movetime_frac -= f;
 134         self.anticheat_speedhack_movetime_count += f;
 135         self.anticheat_speedhack_movetime = self.anticheat_speedhack_movetime_frac + self.anticheat_speedhack_movetime_count;
 136         f = self.anticheat_speedhack_movetime - servertime;
 137         if(self.anticheat_speedhack_offset == 0)
 138                 self.anticheat_speedhack_offset = f;
 139         else
 140         {
 141                 MEAN_ACCUMULATE(anticheat_speedhack, max(0, f - self.anticheat_speedhack_offset), 1);
 142                 self.anticheat_speedhack_offset += (f - self.anticheat_speedhack_offset) * frametime * 0.1;
 143         }
 144
 145         // new generic speedhack detection
 146         if (self.anticheat_speedhack_lasttime > 0) {
 147                 float dt = servertime - self.anticheat_speedhack_lasttime;
 148                 const float falloff = 0.2;
 149                 self.anticheat_speedhack_accu *= exp(-dt * falloff);
 150                 self.anticheat_speedhack_accu += frametime * falloff;
 151                 // NOTE: at cl_netfps x, this actually averages not to 1, but to 1/x * falloff / (1 - exp(-1/x * falloff))
 152                 // For 15 netfps (absolute minimum bearable), and 0.2 falloff, this is: 1.0067
 153                 self.anticheat_speedhack_lasttime = servertime;
 154                 MEAN_ACCUMULATE(anticheat_speedhack_m1, self.anticheat_speedhack_accu, frametime);
 155                 MEAN_ACCUMULATE(anticheat_speedhack_m2, self.anticheat_speedhack_accu, frametime);
 156                 MEAN_ACCUMULATE(anticheat_speedhack_m3, self.anticheat_speedhack_accu, frametime);
 157                 MEAN_ACCUMULATE(anticheat_speedhack_m4, self.anticheat_speedhack_accu, frametime);
 158                 MEAN_ACCUMULATE(anticheat_speedhack_m5, self.anticheat_speedhack_accu, frametime);
 159         } else {
 160                 self.anticheat_speedhack_accu = 1;
 161                 self.anticheat_speedhack_lasttime = servertime;
 162         }
 163
 164         // race/CTS: force kbd movement for fairness
 165         if(g_race || g_cts)
 166         {
 167                 // if record times matter
 168                 // ensure nothing EVIL is being done (i.e. div0_evade)
 169                 // this hinders joystick users though
 170                 // but it still gives SOME analog control
 171                 wishvel_x = fabs(self.movement_x);
 172                 wishvel_y = fabs(self.movement_y);
 173                 if(wishvel_x != 0 && wishvel_y != 0 && wishvel_x != wishvel_y)
 174                 {
 175                         wishvel_z = 0;
 176                         wishspeed = vlen(wishvel);
 177                         if(wishvel_x >= 2 * wishvel_y)
 178                         {
 179                                 // pure X motion
 180                                 if(self.movement_x > 0)
 181                                         self.movement_x = wishspeed;
 182                                 else
 183                                         self.movement_x = -wishspeed;
 184                                 self.movement_y = 0;
 185                         }
 186                         else if(wishvel_y >= 2 * wishvel_x)
 187                         {
 188                                 // pure Y motion
 189                                 self.movement_x = 0;
 190                                 if(self.movement_y > 0)
 191                                         self.movement_y = wishspeed;
 192                                 else
 193                                         self.movement_y = -wishspeed;
 194                         }
 195                         else
 196                         {
 197                                 // diagonal
 198                                 if(self.movement_x > 0)
 199                                         self.movement_x = M_SQRT1_2 * wishspeed;
 200                                 else
 201                                         self.movement_x = -M_SQRT1_2 * wishspeed;
 202                                 if(self.movement_y > 0)
 203                                         self.movement_y = M_SQRT1_2 * wishspeed;
 204                                 else
 205                                         self.movement_y = -M_SQRT1_2 * wishspeed;
 206                         }
 207                 }
 208         }
 209 }
 210
 211 void anticheat_spectatecopy(entity spectatee)
 212 {
 213         // div0_evade -> SPECTATORS
 214         self.angles = spectatee.anticheat_div0_evade_v_angle;
 215 }
 216
 217 void anticheat_prethink()
 218 {
 219         // div0_evade -> SPECTATORS
 220         self.anticheat_div0_evade_offset = 0;
 221 }
 222
 223 string anticheat_display(float f, float tmin, float mi, float ma)
 224 {
 225         string s;
 226         s = ftos(f);
 227         if(f <= mi)
 228                 return strcat(s, ":N");
 229         if(f >= ma)
 230                 return strcat(s, ":Y");
 231         return strcat(s, ":-");
 232 }
 233
 234 void anticheat_report()
 235 {
 236         if(!autocvar_sv_eventlog)
 237                 return;
 238         // TODO(divVerent): Use xonstat to acquire good thresholds.
 239         GameLogEcho(strcat(":anticheat:_time:", ftos(self.playerid), ":", ftos(servertime - self.anticheat_jointime)));
 240         GameLogEcho(strcat(":anticheat:speedhack:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack), 240, 0.1, 0.15)));
 241         GameLogEcho(strcat(":anticheat:speedhack_m1:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack_m1), 240, 0.1, 0.15)));
 242         GameLogEcho(strcat(":anticheat:speedhack_m2:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack_m2), 240, 0.1, 0.15)));
 243         GameLogEcho(strcat(":anticheat:speedhack_m3:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack_m3), 240, 0.1, 0.15)));
 244         GameLogEcho(strcat(":anticheat:speedhack_m4:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack_m4), 240, 0.1, 0.15)));
 245         GameLogEcho(strcat(":anticheat:speedhack_m5:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_speedhack_m5), 240, 0.1, 0.15)));
 246         GameLogEcho(strcat(":anticheat:div0_strafebot_old:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_div0_strafebot_old), 120, 0.3, 0.4)));
 247         GameLogEcho(strcat(":anticheat:div0_strafebot_new:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_div0_strafebot_new), 120, 0.3, 0.4)));
 248         GameLogEcho(strcat(":anticheat:div0_evade:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_div0_evade), 120, 0.1, 0.2)));
 249         GameLogEcho(strcat(":anticheat:idle_snapaim:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_signal) - MEAN_EVALUATE(anticheat_idle_snapaim_noise), 120, 0.1, 0.2)));
 250         GameLogEcho(strcat(":anticheat:idle_snapaim_signal:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_signal), 120, 0.1, 0.2)));
 251         GameLogEcho(strcat(":anticheat:idle_snapaim_noise:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_noise), 120, 0.1, 0.2)));
 252         GameLogEcho(strcat(":anticheat:idle_snapaim_m2:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_m2), 120, 0.1, 0.2)));
 253         GameLogEcho(strcat(":anticheat:idle_snapaim_m3:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_m3), 120, 0.1, 0.2)));
 254         GameLogEcho(strcat(":anticheat:idle_snapaim_m4:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_m4), 120, 0.1, 0.2)));
 255         GameLogEcho(strcat(":anticheat:idle_snapaim_m7:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_m7), 120, 0.1, 0.2)));
 256         GameLogEcho(strcat(":anticheat:idle_snapaim_m10:", ftos(self.playerid), ":", anticheat_display(MEAN_EVALUATE(anticheat_idle_snapaim_m10), 120, 0.1, 0.2)));
 257 }
 258
 259 float anticheat_getvalue(string id)
 260 {
 261         switch(id) {
 262                 case "_time": return servertime - self.anticheat_jointime;
 263                 case "speedhack": return MEAN_EVALUATE(anticheat_speedhack);
 264                 case "speedhack_m1": return MEAN_EVALUATE(anticheat_speedhack_m1);
 265                 case "speedhack_m2": return MEAN_EVALUATE(anticheat_speedhack_m2);
 266                 case "speedhack_m3": return MEAN_EVALUATE(anticheat_speedhack_m3);
 267                 case "speedhack_m4": return MEAN_EVALUATE(anticheat_speedhack_m4);
 268                 case "speedhack_m5": return MEAN_EVALUATE(anticheat_speedhack_m5);
 269                 case "div0_strafebot_old": return MEAN_EVALUATE(anticheat_div0_strafebot_old);
 270                 case "div0_strafebot_new": return MEAN_EVALUATE(anticheat_div0_strafebot_new);
 271                 case "div0_evade": return MEAN_EVALUATE(anticheat_div0_evade);
 272                 case "idle_snapaim": return MEAN_EVALUATE(anticheat_idle_snapaim_signal) - MEAN_EVALUATE(anticheat_idle_snapaim_noise);
 273                 case "idle_snapaim_signal": return MEAN_EVALUATE(anticheat_idle_snapaim_signal);
 274                 case "idle_snapaim_noise": return MEAN_EVALUATE(anticheat_idle_snapaim_noise);
 275                 case "idle_snapaim_m2": return MEAN_EVALUATE(anticheat_idle_snapaim_m2);
 276                 case "idle_snapaim_m3": return MEAN_EVALUATE(anticheat_idle_snapaim_m3);
 277                 case "idle_snapaim_m4": return MEAN_EVALUATE(anticheat_idle_snapaim_m4);
 278                 case "idle_snapaim_m7": return MEAN_EVALUATE(anticheat_idle_snapaim_m7);
 279                 case "idle_snapaim_m10": return MEAN_EVALUATE(anticheat_idle_snapaim_m10);
 280         }
 281         return -1;
 282 }
 283
 284 void anticheat_startframe()
 285 {
 286         anticheat_div0_evade_evasion_delta += frametime * (0.5 + random());
 287 }
 288
 289 void anticheat_fixangle()
 290 {
 291         self.anticheat_fixangle_endtime = servertime + ANTILAG_LATENCY(self) + 0.2;
 292 }
 293
 294 void anticheat_endframe()
 295 {
 296         entity oldself = self;
 297         FOR_EACH_CLIENT(self)
 298                 if (self.fixangle)
 299                         anticheat_fixangle();
 300         self = oldself;
 301         anticheat_div0_evade_evasion_delta += frametime * (0.5 + random());
 302 }
 303
 304 void anticheat_init()
 305 {
 306         self.anticheat_speedhack_offset = 0;
 307         self.anticheat_jointime = servertime;
 308 }
 309
 310 void anticheat_shutdown()
 311 {
 312 }