#! /bin/sh -e

# Configure IP address
IP=$(cat ip.txt)
ip addr add $IP label eth0:pwnables dev eth0

# Set up chroot environment
# We never umount any of this since it's all just in RAM
mkdir -p /mnt/pwnables-root
grep -q pwnables-root /proc/mounts || mount -o bind / /mnt/pwnables-root
grep -q pwnables-var /proc/mounts  || mount -t tmpfs -o size=5m,mode=0755 pwnables-var /mnt/pwnables-root/var
grep -q pwnables-tmp /proc/mounts  || mount -t tmpfs -o size=15k pwnables-tmp /mnt/pwnables-root/tmp
grep -q pwnables-home /proc/mounts || mount -t tmpfs -o size=5m pwnables-home /mnt/pwnables-root/home

# Make some skeleton junk
install -o root -m 0755 -d /mnt/pwnables-root/var/lib
install -o root -m 0755 -d /mnt/pwnables-root/var/lib/ctf
install -o root -m 0755 -d /mnt/pwnables-root/var/lib/ctf/tokens
install -o root -m 0755 -d /mnt/pwnables-root/var/log
install -o root -m 0755 -d /mnt/pwnables-root/var/spool
install -o root -m 0755 -d /mnt/pwnables-root/var/cache
install -o root -m 0777 -d /mnt/pwnables-root/var/run
install -o root -m 0777 -d /mnt/pwnables-root/var/cache

# Install the pwnables
install -o root -d /mnt/pwnables-root/home/alice/
install -o bob -m 0111 /opt/pwnables/bin/gimmie /mnt/pwnables-root/home/alice/

# ltrace needs to read the binary
install -o bob -m 0555 /opt/pwnables/bin/ltraceme /mnt/pwnables-root/home/alice/

# straceme and killme need to be suid, to prevent LD_PRELOAD
install -o bob -m 04111 /opt/pwnables/bin/straceme /mnt/pwnables-root/home/alice/
install -o bob -m 04111 /opt/pwnables/bin/killme /mnt/pwnables-root/home/alice/
    
# Set up links for tokens
mkdir -p /var/lib/ctf/tokens
for puzzle in gimmie ltraceme straceme killme; do
    ln -sf /mnt/pwnables-root/var/lib/ctf/tokens/$puzzle /var/lib/ctf/tokens/$puzzle
done

exec tcpsvd -C 5:"Let's not be greedy" ${IP%/*} 23 /sbin/telnetd -l ./pwnie