Don't leak stack garbage

character.c

@@ -319,7 +319,7 @@ void genBackground(){
 	}
 }
 
-char * genChar(char* output){
+size_t genChar(char* output, size_t maxlen){
 	profs = 0;
 	languages = 0;
 	for(int i = 0; i <= 100; i++){
@@ -333,113 +333,113 @@ char * genChar(char* output){
 		stats[i] = dieroll(3,6);
 		mods[i] = floor((stats[i]/2)-5);
 	}
-	snprintf(output, 512, "Race = %s\r\nBackground = %s\r\nClass = %s\r\nStr = %d %d\r\nDex = %d %d\r\nCon = %d %d\r\nInt = %d %d\r\nWis = %d %d\r\nCha = %d %d\r\n\r\nHP: %d\r\n", race, background, class, stats[STR], mods[STR], stats[DEX], mods[DEX], stats[CON], mods[CON], stats[INT], mods[INT], stats[WIS], mods[WIS], stats[CHA], mods[CHA], hp);
+	snprintf(output, maxlen, "Race = %s\r\nBackground = %s\r\nClass = %s\r\nStr = %d %d\r\nDex = %d %d\r\nCon = %d %d\r\nInt = %d %d\r\nWis = %d %d\r\nCha = %d %d\r\n\r\nHP: %d\r\n", race, background, class, stats[STR], mods[STR], stats[DEX], mods[DEX], stats[CON], mods[CON], stats[INT], mods[INT], stats[WIS], mods[WIS], stats[CHA], mods[CHA], hp);
 
 
-	strlcat(output,"Proficiences:\r\n",512);
+	strlcat(output,"Proficiences:\r\n",maxlen);
 	if((ATHLETICS & profs) != 0){
-		strlcat(output,"Athletics\r\n",512);
+		strlcat(output,"Athletics\r\n",maxlen);
 	}
 	if((ACROBATICS & profs) != 0){
-		strlcat(output,"Acrobatics\r\n",512);
+		strlcat(output,"Acrobatics\r\n",maxlen);
 	}
 	if((SLEIGHTOFHAND & profs) != 0){
-		strlcat(output,"Sleight of Hand\r\n",512);
+		strlcat(output,"Sleight of Hand\r\n",maxlen);
 	}
 	if((STEALTH & profs) != 0){
-		strlcat(output,"Stealth\r\n",512);
+		strlcat(output,"Stealth\r\n",maxlen);
 	}
 	if((ARCANA & profs) != 0){
-		strlcat(output,"Arcana\r\n",512);
+		strlcat(output,"Arcana\r\n",maxlen);
 	}
 	if((HISTORY & profs) != 0){
-		strlcat(output,"History\r\n",512);
+		strlcat(output,"History\r\n",maxlen);
 	}
 	if((INVESTIGATION & profs) != 0){
-		strlcat(output,"Investigation\r\n",512);
+		strlcat(output,"Investigation\r\n",maxlen);
 	}
 	if((NATURE & profs) != 0){
-		strlcat(output,"Nature\r\n",512);
+		strlcat(output,"Nature\r\n",maxlen);
 	}
 	if((RELIGION & profs) != 0){
-		strlcat(output,"Regligion\r\n",512);
+		strlcat(output,"Regligion\r\n",maxlen);
 	}
 	if((ANIMALHANDLING & profs) != 0){
-		strlcat(output,"Animal Handling\r\n",512);
+		strlcat(output,"Animal Handling\r\n",maxlen);
 	}
 	if((INSIGHT & profs) != 0){
-		strlcat(output,"Insight\r\n",512);
+		strlcat(output,"Insight\r\n",maxlen);
 	}
 	if((MEDICINE & profs) != 0){
-		strlcat(output,"Medicine\r\n",512);
+		strlcat(output,"Medicine\r\n",maxlen);
 	}
 	if((PERCEPTION & profs) != 0){
-		strlcat(output,"Perception\r\n",512);
+		strlcat(output,"Perception\r\n",maxlen);
 	}
 	if((SURVIVAL & profs) != 0){
-		strlcat(output,"Survival\r\n",512);
+		strlcat(output,"Survival\r\n",maxlen);
 	}
 	if((DECEPTION & profs) != 0){
-		strlcat(output,"Deception\r\n",512);
+		strlcat(output,"Deception\r\n",maxlen);
 	}
 	if((INTIMIDATION & profs) != 0){
-		strlcat(output,"Intimidation\r\n",512);
+		strlcat(output,"Intimidation\r\n",maxlen);
 	}
 	if((PERFORMANCE & profs) != 0){
-		strlcat(output,"Performance\r\n",512);
+		strlcat(output,"Performance\r\n",maxlen);
 	}
 	if((PERSUASION & profs) != 0){
-		strlcat(output,"Persuaion\r\n",512);
+		strlcat(output,"Persuaion\r\n",maxlen);
 	}
 
-	strlcat(output,"\r\nLanguages:\r\nCommon\r\n",512);
+	strlcat(output,"\r\nLanguages:\r\nCommon\r\n",maxlen);
 	if((ABYSSAL & languages) != 0){
-		strlcat(output,"Abyssal\r\n",512);
+		strlcat(output,"Abyssal\r\n",maxlen);
 	}
 	if((CELESTIAL & languages) != 0){
-		strlcat(output,"Celestial\r\n",512);
+		strlcat(output,"Celestial\r\n",maxlen);
 	}
 	if((DRACONIC & languages) != 0){
-		strlcat(output,"Draconic\r\n",512);
+		strlcat(output,"Draconic\r\n",maxlen);
 	}
 	if((DEEPSPEECH & languages) != 0){
-		strlcat(output,"Deep Speech\r\n",512);
+		strlcat(output,"Deep Speech\r\n",maxlen);
 	}
 	if((INFERNAL & languages) != 0){
-		strlcat(output,"Infernal\r\n",512);
+		strlcat(output,"Infernal\r\n",maxlen);
 	}
 	if((PRIMORDIAL & languages) != 0){
-		strlcat(output,"Primordial\r\n",512);
+		strlcat(output,"Primordial\r\n",maxlen);
 	}
 	if((SYLVAN & languages) != 0){
-		strlcat(output,"Sylvan\r\n",512);
+		strlcat(output,"Sylvan\r\n",maxlen);
 	}
 	if((UNDERCOMMON & languages) != 0){
-		strlcat(output,"Undercommon\r\n",512);
+		strlcat(output,"Undercommon\r\n",maxlen);
 	}
 	if((DWARVISH & languages) != 0){
-		strlcat(output,"Dwarvish\r\n",512);
+		strlcat(output,"Dwarvish\r\n",maxlen);
 	}
 	if((ELVISH & languages) != 0){
-		strlcat(output,"Elvish\r\n",512);
+		strlcat(output,"Elvish\r\n",maxlen);
 	}
 	if((GIANT & languages) != 0){
-		strlcat(output,"Giant\r\n",512);
+		strlcat(output,"Giant\r\n",maxlen);
 	}
 	if((GNOMISH & languages) != 0){
-		strlcat(output,"Gnome\r\n",512);
+		strlcat(output,"Gnome\r\n",maxlen);
 	}
 	if((GOBLIN & languages) != 0){
-		strlcat(output,"Goblin\r\n",512);
+		strlcat(output,"Goblin\r\n",maxlen);
 	}
 	if((HALFLISH & languages) != 0){
-		strlcat(output,"Halfling\r\n",512);
+		strlcat(output,"Halfling\r\n",maxlen);
 	}
 	if((ORC & languages) != 0){
-		strlcat(output,"Orcish\r\n",512);
+		strlcat(output,"Orcish\r\n",maxlen);
 	}
-	strlcat(output,"\r\nOther Profs: ",512);
+	strlcat(output,"\r\nOther Profs: ",maxlen);
-	strlcat(output,otherprofs,512);
+	strlcat(output,otherprofs,maxlen);
-	strlcat(output,"\r\n",512);
+	strlcat(output,"\r\n",maxlen);
-	return output;
+	return strlen(output);
 }

chargen.c

@@ -13,6 +13,11 @@
 
 #include "chargen.h"
 
+enum {
+	TCP_MAXLEN = 1024,
+	UDP_MAXLEN = 512,
+};
+
 void usage_and_die(const char *myname, const char *fmt, ...)
 {
 	if (fmt)
@@ -246,9 +251,9 @@ int main(int argc, char **argv)
 					printf("Responding to packet from %s:%s...\n", hbuf, sbuf);
 
 				//rval = sendto(s, "chargen data\r\n", 14, 0, sa, len);
-				char character[512];
+				char character[UDP_MAXLEN];
-				genChar(character);
+				size_t datalen = genChar(character, sizeof character);
-				rval = sendto(s, character, 512, 0, sa, len);
+				rval = sendto(s, character, datalen, 0, sa, len);
 				if (rval == -1)
 					warn("sendto");
 			}
@@ -283,9 +288,10 @@ int main(int argc, char **argv)
 					printf("WTF?  i=%u num_stream=%u stream_fds[i]=%d s=%d\n", i, num_stream, stream_fds[i], s);
 					continue;
 				}
-				char character[512];
+				char character[TCP_MAXLEN];
-				genChar(character);
+				size_t datalen = genChar(character, sizeof character);
-				if (write(s, character, 512) == -1)
+				/* TODO: Detect short writes and save the rest of the buffer for later */
+				if (write(s, character, datalen) == -1)
 				{
 					warn("write");
 					printf("Closing stream connection\n");

chargen.h

@@ -1,6 +1,8 @@
 #ifndef H_CHARGEN
 #define H_CHARGEN
 
-char* genChar();
+#include <stddef.h>
+
+size_t genChar(char *, size_t);
 
 #endif