initialization functions

1 files changed, 116 insertions, 0 deletions

diff --git a/src/init.go b/src/init.go
new file mode 100644
index 0000000..679e01b
--- /dev/null
+++ b/src/init.go
@@ -0,0 +1,116 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"math/rand"
+	"time"
+
+	r2pipe "github.com/radare/r2pipe-go"
+)
+
+// buildBot builds the bot located at the given path.
+func buildBot(config Config, path string) Bot {
+	log.Println("[+] Building the bot")
+
+	// open radare without input for building the bot
+	r2p1, err := r2pipe.NewPipe("--")
+	if err != nil {
+		panic(err)
+	}
+	defer r2p1.Close()
+
+	// Compile a warrior using rasm2
+	//
+	// This uses the given architecture, the given bitness and the given path in
+	// rasm2 to compile the bot
+	radareCommand := fmt.Sprintf("rasm2 -a %s -b %d -f %s", config.Arch, config.Bits, path)
+	botSource := r2cmd(r2p1, radareCommand)
+
+	bot := Bot{
+		Path:   path,
+		Source: botSource,
+	}
+
+	// return the bot
+	return bot
+}
+
+// init initializes the arena
+func initArena(config Config) *r2pipe.Pipe {
+	log.Println("[+] Initializing the arena")
+	log.Printf("[ ] Allocating %d bytes of memory...", config.Memsize)
+
+	// alocate memory
+	r2p, err := r2pipe.NewPipe(fmt.Sprintf("malloc://%d", config.Memsize))
+	if err != nil {
+		panic(err)
+	}
+	log.Println("[+] Memoy successfully allocated \\o/")
+
+	// define the architecture and the bitness
+	_ = r2cmd(r2p, fmt.Sprintf("e asm.arch = %s", config.Arch))
+	_ = r2cmd(r2p, fmt.Sprintf("e asm.bits = %d", config.Bits))
+
+	// enable colors
+	_ = r2cmd(r2p, "e scr.color = true")
+
+	log.Println("[+] Initializing the ESIL VM")
+	// initialize ESIL VM state
+	_ = r2cmd(r2p, "aei")
+
+	// initialize ESIL VM stack
+	_ = r2cmd(r2p, "aeim")
+
+	// return the pipe
+	return r2p
+
+}
+
+// getRandomOffsets returns random offsets for all bots
+// This is used to get the offset the bots are initially placed in
+func getRandomOffsets(config Config) []int {
+
+	var amountOfBots int = len(config.Bots)
+	var offsets []int
+	var roundCounter int = 0
+
+	// seed the random number generator
+	rand.Seed(time.Now().UTC().UnixNano())
+
+	for {
+		// define an integer array to store the random offsets in
+		//var offsets []int = []int{}
+
+		// define a random address
+		address := rand.Intn(config.Memsize - config.MaxProgSize)
+
+		// for all bots, try to generate another random address after the intially
+		// generated address and test if it fits in memory
+		for i := 0; i < amountOfBots; i++ {
+			offsets = append(offsets, address)
+
+			// generate a random value in range [maxProgSize, maxProgSize + 300)
+			address += rand.Intn(config.MaxProgSize+300) + config.MaxProgSize
+
+			// if there is not enough memory remaining after the last generated
+			// address, start from be beginning
+			if address+config.MaxProgSize > config.Memsize {
+				roundCounter++
+				continue
+			}
+		}
+
+		// if enough addresses have been generated, break out of the for loop
+		break
+	}
+
+	log.Printf("[+] Initial bot positions found after %d trues", roundCounter)
+
+	return offsets
+}
+
+// place the bot in the arena at the given address
+func placeBot(r2p *r2pipe.Pipe, bot Bot, address int) {
+	_ = r2cmd(r2p, fmt.Sprintf("wx %s @ %d", bot, address))
+}