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Code Issues Releases Wiki Activity

Add bounds checks to functions taking in entity/blocks/linecross indices

Browse source 
The main ones to beware of here are entityclass::updateentities(),
entityclass::updateentitylogic(), and entityclass::entitymapcollision().
They would index out-of-bounds and thus commit Undefined Behavior if the
entity was removed in entityclass::updateentities(). And it would've
been fine enough if I only added bounds checks to those functions.

However, I decided to be a bit more defensive and play it safe, and
added bounds checks to ALL functions taking in not only an entity
indice, but also blocks and linecrosskludge indices.
This commit is contained in:
Misa 2020-05-04 16:41:30 -07:00 committed by Ethan Lee
parent c8d50d3067
commit 8a78318990
1 changed files with 131 additions and 0 deletions
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131
desktop_version/src/Entity.cpp
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@ -5,6 +5,11 @@
bool entityclass::checktowerspikes(int t)
{
if (t < 0 || t >= (int) entities.size())
{
return false;
}
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy;
tempw = entities[t].w;
@ -1033,6 +1038,10 @@ void entityclass::createblock( int t, int xp, int yp, int w, int h, int trig /*=
void entityclass::removeentity(int t)
{
if (t < 0 || t > (int) entities.size())
{
return;
}
entities.erase(entities.begin() + t);
}
@ -1043,6 +1052,10 @@ void entityclass::removeallblocks()
void entityclass::removeblock( int t )
{
if (t < 0 || t > (int) blocks.size())
{
return;
}
blocks.erase(blocks.begin() + t);
}
@ -1067,12 +1080,20 @@ void entityclass::removetrigger( int t )
void entityclass::copylinecross( int t )
{
if (t < 0 || t > (int) entities.size())
{
return;
}
//Copy entity t into the first free linecrosskludge entity
linecrosskludge.push_back(entities[t]);
}
void entityclass::revertlinecross( int t, int s )
{
if (t < 0 || t > (int) entities.size() || s < 0 || s > (int) linecrosskludge.size())
{
return;
}
//Restore entity t info from linecrossing s
entities[t].onentity = linecrosskludge[s].onentity;
entities[t].state = linecrosskludge[s].state;
@ -2042,6 +2063,11 @@ void entityclass::createentity( float xp, float yp, int t, float vx /*= 0*/, flo
void entityclass::updateentities( int i )
{
if (i < 0 || i >= (int) entities.size())
{
return;
}
if(entities[i].statedelay<=0)
{
switch(entities[i].type)
@ -3189,6 +3215,11 @@ void entityclass::updateentities( int i )
void entityclass::animateentities( int _i )
{
if (_i < 0 || _i >= (int) entities.size())
{
return;
}
if(entities[_i].statedelay < 1)
{
switch(entities[_i].type)
@ -3687,6 +3718,11 @@ void entityclass::rect2set( int xi, int yi, int wi, int hi )
bool entityclass::entitycollide( int a, int b )
{
if (a < 0 || a > (int) entities.size() || b < 0 || b > (int) entities.size())
{
return false;
}
//Do entities a and b collide?
tempx = entities[a].xp + entities[a].cx;
tempy = entities[a].yp + entities[a].cy;
@ -3756,6 +3792,11 @@ bool entityclass::scmcheckdamage()
void entityclass::settemprect( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
//setup entity t in temprect
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy;
@ -3939,6 +3980,11 @@ int entityclass::yline( int a, int b )
bool entityclass::entityhlinecollide( int t, int l )
{
if (t < 0 || t >= (int) entities.size() || l < 0 || l >= (int) entities.size())
{
return false;
}
//Returns true is entity t collided with the horizontal line l.
if(entities[t].xp + entities[t].cx+entities[t].w>=entities[l].xp)
{
@ -3960,6 +4006,11 @@ bool entityclass::entityhlinecollide( int t, int l )
bool entityclass::entityvlinecollide( int t, int l )
{
if (t < 0 || t >= (int) entities.size() || l < 0 || l >= (int) entities.size())
{
return false;
}
//Returns true is entity t collided with the vertical line l.
if(entities[t].yp + entities[t].cy+entities[t].h>=entities[l].yp
&& entities[t].yp + entities[t].cy<=entities[l].yp+entities[l].h)
@ -3978,6 +4029,11 @@ bool entityclass::entityvlinecollide( int t, int l )
}
bool entityclass::entitywarphlinecollide(int t, int l) {
if (t < 0 || t >= (int) entities.size() || l < 0 || l >= (int) entities.size())
{
return false;
}
//Returns true is entity t collided with the horizontal line l.
if(entities[t].xp + entities[t].cx+entities[t].w>=entities[l].xp
&&entities[t].xp + entities[t].cx<=entities[l].xp+entities[l].w){
@ -4010,6 +4066,11 @@ bool entityclass::entitywarphlinecollide(int t, int l) {
}
bool entityclass::entitywarpvlinecollide(int t, int l) {
if (t < 0 || t >= (int) entities.size() || l < 0 || l >= (int) entities.size())
{
return false;
}
//Returns true is entity t collided with the vertical warp line l.
if(entities[t].yp + entities[t].cy+entities[t].h>=entities[l].yp
&& entities[t].yp + entities[t].cy <= entities[l].yp + entities[l].h) {
@ -4039,6 +4100,11 @@ bool entityclass::entitywarpvlinecollide(int t, int l) {
float entityclass::entitycollideplatformroof( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return -1000;
}
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy -1;
tempw = entities[t].w;
@ -4055,6 +4121,11 @@ float entityclass::entitycollideplatformroof( int t )
float entityclass::entitycollideplatformfloor( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return -1000;
}
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy + 1;
tempw = entities[t].w;
@ -4071,6 +4142,11 @@ float entityclass::entitycollideplatformfloor( int t )
bool entityclass::entitycollidefloor( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return false;
}
//see? like here, for example!
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy + 1;
@ -4084,6 +4160,11 @@ bool entityclass::entitycollidefloor( int t )
bool entityclass::entitycollideroof( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return false;
}
//and here!
tempx = entities[t].xp + entities[t].cx;
tempy = entities[t].yp + entities[t].cy - 1;
@ -4097,6 +4178,11 @@ bool entityclass::entitycollideroof( int t )
bool entityclass::testwallsx( int t, int tx, int ty )
{
if (t < 0 || t >= (int) entities.size())
{
return false;
}
tempx = tx + entities[t].cx;
tempy = ty + entities[t].cy;
tempw = entities[t].w;
@ -4143,6 +4229,11 @@ bool entityclass::testwallsx( int t, int tx, int ty )
bool entityclass::testwallsy( int t, float tx, float ty )
{
if (t < 0 || t >= (int) entities.size())
{
return false;
}
tempx = static_cast<int>(tx) + entities[t].cx;
tempy = static_cast<int>(ty) + entities[t].cy;
tempw = entities[t].w;
@ -4190,6 +4281,11 @@ bool entityclass::testwallsy( int t, float tx, float ty )
void entityclass::fixfriction( int t, float xfix, float xrate, float yrate )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
if (entities[t].vx > xfix) entities[t].vx -= xrate;
if (entities[t].vx < xfix) entities[t].vx += xrate;
if (entities[t].vy > 0) entities[t].vy -= yrate;
@ -4205,6 +4301,11 @@ void entityclass::fixfriction( int t, float xfix, float xrate, float yrate )
void entityclass::applyfriction( int t, float xrate, float yrate )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
if (entities[t].vx > 0.00f) entities[t].vx -= xrate;
if (entities[t].vx < 0.00f) entities[t].vx += xrate;
if (entities[t].vy > 0.00f) entities[t].vy -= yrate;
@ -4220,6 +4321,11 @@ void entityclass::applyfriction( int t, float xrate, float yrate )
void entityclass::updateentitylogic( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
entities[t].oldxp = entities[t].xp;
entities[t].oldyp = entities[t].yp;
@ -4257,6 +4363,11 @@ void entityclass::updateentitylogic( int t )
void entityclass::entitymapcollision( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
if (testwallsx(t, entities[t].newxp, entities[t].yp))
{
entities[t].xp = entities[t].newxp;
@ -4280,6 +4391,11 @@ void entityclass::entitymapcollision( int t )
void entityclass::movingplatformfix( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
//If this intersects the player, then we move the player along it
int j = getplayer();
if (entitycollide(t, j))
@ -4316,6 +4432,11 @@ void entityclass::movingplatformfix( int t )
void entityclass::scmmovingplatformfix( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
//If this intersects the SuperCrewMate, then we move them along it
int j = getscm();
if (entitycollide(t, j))
@ -4350,12 +4471,22 @@ void entityclass::scmmovingplatformfix( int t )
void entityclass::hormovingplatformfix( int t )
{
if (t < 0 || t >= (int) entities.size())
{
return;
}
//If this intersects the player, then we move the player along it
//for horizontal platforms, this is simplier
createblock(0, entities[t].xp, entities[t].yp, entities[t].w, entities[t].h);
}
void entityclass::customwarplinecheck(int i) {
if (i < 0 || i >= (int) entities.size())
{
return;
}
//Turns on obj.customwarpmodevon and obj.customwarpmodehon if player collides
//with warp lines