3 files changed, 111 insertions, 0 deletions
diff --git a/roles/base/defaults/main.yaml b/roles/base/defaults/main.yaml
new file mode 100644
index 00000000..282c4fd7
--- /dev/null
+++ b/roles/base/defaults/main.yaml
@@ -0,0 +1,7 @@
+---
+sysctl_config_user: {}
+
+modules_blacklist:
+  net: [dccp, sctp, rds, tipc]
+  fs: [cramfs, freevxfs, hfs, hfsplus, jffs2]
+  misc: [bluetooth, firewire-core, n_hdlc, net-pf-31, soundcore, thunderbolt, usb-midi]
diff --git a/roles/base/tasks/main.yaml b/roles/base/tasks/main.yaml
new file mode 100644
index 00000000..91349e50
--- /dev/null
+++ b/roles/base/tasks/main.yaml
@@ -0,0 +1,59 @@
+---
+- name: apt - Install base system tools
+  apt: name={{ item }} state=present
+  with_items:
+    - htop
+    - dstat
+    - lsof
+    - gawk
+    - psmisc
+    - less
+    - debian-goodies
+    - screen
+    - mtr-tiny
+    - tcpdump
+    - unp
+    - sudo
+    - haveged
+    - dbus
+    - libpam-systemd
+    - aptitude
+    - ca-certificates
+    - file
+
+- name: Remove startup message from screen
+  lineinfile:
+    regexp: "^startup_message"
+    line: "startup_message off"
+    dest: /etc/screenrc
+    mode: 0644
+  tags:
+    - screen
+
+- name: Ensure /root is not world accessible
+  file:
+    path: /root
+    mode: 0700
+    owner: root
+    group: root
+    state: directory
+
+- name: disable net/fs/misc kernel modules
+  lineinfile:
+    dest: /etc/modprobe.d/disablemod.conf
+    line: "install {{ item }} /bin/true"
+    create: yes
+    owner: root
+    group: root
+    mode: 0644
+  with_items: "{{ modules_blacklist.net | union(modules_blacklist.fs) | union(modules_blacklist.misc) }}"
+
+- name: Change various sysctl-settings, look at the sysctl-vars file for documentation
+  sysctl:
+    name: '{{ item.key }}'
+    value: '{{ item.value }}'
+    sysctl_set: yes
+    state: present
+    reload: yes
+    ignoreerrors: yes
+  with_dict: '{{ sysctl_config | combine(sysctl_config_user) }}'
diff --git a/roles/base/vars/main.yaml b/roles/base/vars/main.yaml
new file mode 100644
index 00000000..557a4a7c
--- /dev/null
+++ b/roles/base/vars/main.yaml
@@ -0,0 +1,45 @@
+# SYSTEM CONFIGURATION
+# ====================
+# These are not meant to be modified by the user
+
+#
+# To adjust these settings use sysctl_config_user dict
+#
+sysctl_config:
+
+  # Enable RFC-recommended source validation feature.
+  net.ipv4.conf.all.rp_filter: 1
+  net.ipv4.conf.default.rp_filter: 1
+
+  # Log packets with impossible addresses to kernel log? yes
+  net.ipv4.conf.all.log_martians: 1
+  net.ipv4.conf.default.log_martians: 1
+
+  # Reduce the surface on SMURF attacks.
+  # Make sure to ignore ECHO broadcasts, which are only required in broad network analysis.
+  net.ipv4.icmp_echo_ignore_broadcasts: 1
+
+  # There is no reason to accept bogus error responses from ICMP, so ignore them instead.
+  net.ipv4.icmp_ignore_bogus_error_responses: 1
+
+  # Limit the amount of traffic the system uses for ICMP.
+  net.ipv4.icmp_ratelimit: 1000
+
+  # Send redirects, if router, but this is just server
+  net.ipv4.conf.all.send_redirects: 0
+  net.ipv4.conf.default.send_redirects: 0
+  net.ipv4.conf.all.accept_redirects: 0
+  net.ipv4.conf.default.accept_redirects: 0
+  net.ipv6.conf.all.accept_redirects: 0
+  net.ipv6.conf.default.accept_redirects: 0
+  net.ipv4.conf.all.secure_redirects: 0
+  net.ipv4.conf.default.secure_redirects: 0
+
+  net.ipv4.conf.all.accept_source_route: 0
+  net.ipv4.conf.default.accept_source_route: 0
+
+  # Protect against wrapping sequence numbers at gigabit speeds
+  net.ipv4.tcp_timestamps: 0
+
+  # Prevent against the common 'syn flood attack'
+  net.ipv4.tcp_syncookies: 1