freedombone-utils-firewall 16KB

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  1. #!/bin/bash
  2. #
  3. # .---. . .
  4. # | | |
  5. # |--- .--. .-. .-. .-.| .-. .--.--. |.-. .-. .--. .-.
  6. # | | (.-' (.-' ( | ( )| | | | )( )| | (.-'
  7. # ' ' --' --' -' - -' ' ' -' -' -' ' - --'
  8. #
  9. # Freedom in the Cloud
  10. #
  11. # Firewall functions
  12. #
  13. # TODO: in future investigate using nftables
  14. #
  15. # License
  16. # =======
  17. #
  18. # Copyright (C) 2014-2016 Bob Mottram <bob@freedombone.net>
  19. #
  20. # This program is free software: you can redistribute it and/or modify
  21. # it under the terms of the GNU Affero General Public License as published by
  22. # the Free Software Foundation, either version 3 of the License, or
  23. # (at your option) any later version.
  24. #
  25. # This program is distributed in the hope that it will be useful,
  26. # but WITHOUT ANY WARRANTY; without even the implied warranty of
  27. # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  28. # GNU Affero General Public License for more details.
  29. #
  30. # You should have received a copy of the GNU Affero General Public License
  31. # along with this program. If not, see <http://www.gnu.org/licenses/>.
  32. FIREWALL_CONFIG=$HOME/${PROJECT_NAME}-firewall.cfg
  33. function save_firewall_settings {
  34. iptables-save > /etc/firewall.conf
  35. ip6tables-save > /etc/firewall6.conf
  36. printf '#!/bin/sh\n' > /etc/network/if-up.d/iptables
  37. printf 'iptables-restore < /etc/firewall.conf\n' >> /etc/network/if-up.d/iptables
  38. printf 'ip6tables-restore < /etc/firewall6.conf\n' >> /etc/network/if-up.d/iptables
  39. if [ -f /etc/network/if-up.d/iptables ]; then
  40. chmod +x /etc/network/if-up.d/iptables
  41. fi
  42. }
  43. function global_rate_limit {
  44. if ! grep -q "tcp_challenge_ack_limit" /etc/sysctl.conf; then
  45. echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' >> /etc/sysctl.conf
  46. else
  47. sed -i 's|net.ipv4.tcp_challenge_ack_limit.*|net.ipv4.tcp_challenge_ack_limit = 999999999|g' /etc/sysctl.conf
  48. fi
  49. sysctl -p -q
  50. }
  51. function enable_ipv6 {
  52. # endure that ipv6 is enabled and can route
  53. sed -i 's/net.ipv6.conf.all.disable_ipv6.*/net.ipv6.conf.all.disable_ipv6 = 0/g' /etc/sysctl.conf
  54. #sed -i "s/net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 1/g" /etc/sysctl.conf
  55. #sed -i "s/net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 1/g" /etc/sysctl.conf
  56. sed -i "s/net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=1/g" /etc/sysctl.conf
  57. echo 1 > /proc/sys/net/ipv6/conf/all/forwarding
  58. }
  59. function configure_firewall {
  60. if [ $INSTALLING_MESH ]; then
  61. mesh_firewall
  62. return
  63. fi
  64. if grep -q "RELATED" /etc/firewall.conf; then
  65. # recreate the firewall to remove RELATED
  66. sed -i "/firewall/d" $COMPLETION_FILE
  67. fi
  68. if [[ $(is_completed $FUNCNAME) == "1" ]]; then
  69. return
  70. fi
  71. if [[ $INSTALLED_WITHIN_DOCKER == "yes" ]]; then
  72. # docker does its own firewalling
  73. return
  74. fi
  75. iptables -P INPUT ACCEPT
  76. ip6tables -P INPUT ACCEPT
  77. iptables -F
  78. ip6tables -F
  79. iptables -t nat -F
  80. ip6tables -t nat -F
  81. iptables -X
  82. ip6tables -X
  83. iptables -P INPUT DROP
  84. ip6tables -P INPUT DROP
  85. iptables -P FORWARD DROP
  86. ip6tables -P FORWARD DROP
  87. iptables -A INPUT -i lo -j ACCEPT
  88. iptables -A INPUT -m conntrack --ctstate ESTABLISHED -j ACCEPT
  89. # Make sure incoming tcp connections are SYN packets
  90. iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP
  91. # Drop packets with incoming fragments
  92. iptables -A INPUT -f -j DROP
  93. # Drop bogons
  94. iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP
  95. iptables -A INPUT -p tcp --tcp-flags ALL FIN,PSH,URG -j DROP
  96. iptables -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
  97. # Incoming malformed NULL packets:
  98. iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP
  99. mark_completed $FUNCNAME
  100. }
  101. function configure_firewall_ping {
  102. if [[ $(is_completed $FUNCNAME) == "1" ]]; then
  103. return
  104. fi
  105. # Only allow ping for mesh installs
  106. if [[ $SYSTEM_TYPE != "mesh"* ]]; then
  107. return
  108. fi
  109. iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
  110. iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT
  111. function_check save_firewall_settings
  112. save_firewall_settings
  113. mark_completed $FUNCNAME
  114. }
  115. function configure_internet_protocol {
  116. if [[ $(is_completed $FUNCNAME) == "1" ]]; then
  117. return
  118. fi
  119. if [[ $SYSTEM_TYPE == "mesh"* ]]; then
  120. return
  121. fi
  122. sed -i "s/#net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies=1/g" /etc/sysctl.conf
  123. sed -i "s/#net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
  124. sed -i "s/#net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
  125. sed -i "s/#net.ipv4.conf.all.send_redirects.*/net.ipv4.conf.all.send_redirects = 0/g" /etc/sysctl.conf
  126. sed -i "s/#net.ipv4.conf.all.accept_source_route.*/net.ipv4.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
  127. sed -i "s/#net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
  128. sed -i "s/#net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter=1/g" /etc/sysctl.conf
  129. sed -i "s/#net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter=1/g" /etc/sysctl.conf
  130. sed -i "s/#net.ipv4.ip_forward.*/net.ipv4.ip_forward=0/g" /etc/sysctl.conf
  131. sed -i "s/#net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=0/g" /etc/sysctl.conf
  132. sed -i "s/# net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies=1/g" /etc/sysctl.conf
  133. sed -i "s/# net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
  134. sed -i "s/# net.ipv6.conf.all.accept_redirects.*/net.ipv6.conf.all.accept_redirects = 0/g" /etc/sysctl.conf
  135. sed -i "s/# net.ipv4.conf.all.send_redirects.*/net.ipv4.conf.all.send_redirects = 0/g" /etc/sysctl.conf
  136. sed -i "s/# net.ipv4.conf.all.accept_source_route.*/net.ipv4.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
  137. sed -i "s/# net.ipv6.conf.all.accept_source_route.*/net.ipv6.conf.all.accept_source_route = 0/g" /etc/sysctl.conf
  138. sed -i "s/# net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter=1/g" /etc/sysctl.conf
  139. sed -i "s/# net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter=1/g" /etc/sysctl.conf
  140. sed -i "s/# net.ipv4.ip_forward.*/net.ipv4.ip_forward=0/g" /etc/sysctl.conf
  141. sed -i "s/# net.ipv6.conf.all.forwarding.*/net.ipv6.conf.all.forwarding=0/g" /etc/sysctl.conf
  142. if ! grep -q "ignore pings" /etc/sysctl.conf; then
  143. echo '# ignore pings' >> /etc/sysctl.conf
  144. echo 'net.ipv4.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
  145. echo 'net.ipv6.icmp_echo_ignore_all = 1' >> /etc/sysctl.conf
  146. fi
  147. if ! grep -q "disable ipv6" /etc/sysctl.conf; then
  148. echo '# disable ipv6' >> /etc/sysctl.conf
  149. echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf
  150. fi
  151. if ! grep -q "net.ipv4.tcp_synack_retries" /etc/sysctl.conf; then
  152. echo 'net.ipv4.tcp_synack_retries = 2' >> /etc/sysctl.conf
  153. echo 'net.ipv4.tcp_syn_retries = 1' >> /etc/sysctl.conf
  154. fi
  155. if ! grep -q "keepalive" /etc/sysctl.conf; then
  156. echo '# keepalive' >> /etc/sysctl.conf
  157. echo 'net.ipv4.tcp_keepalive_probes = 9' >> /etc/sysctl.conf
  158. echo 'net.ipv4.tcp_keepalive_intvl = 75' >> /etc/sysctl.conf
  159. echo 'net.ipv4.tcp_keepalive_time = 7200' >> /etc/sysctl.conf
  160. fi
  161. if ! grep -q "net.ipv4.conf.default.send_redirects" /etc/sysctl.conf; then
  162. echo "net.ipv4.conf.default.send_redirects = 0" >> /etc/sysctl.conf
  163. else
  164. sed -i "s|# net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
  165. sed -i "s|#net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
  166. sed -i "s|net.ipv4.conf.default.send_redirects.*|net.ipv4.conf.default.send_redirects = 0|g" /etc/sysctl.conf
  167. fi
  168. if ! grep -q "net.ipv4.conf.all.secure_redirects" /etc/sysctl.conf; then
  169. echo "net.ipv4.conf.all.secure_redirects = 0" >> /etc/sysctl.conf
  170. else
  171. sed -i "s|# net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
  172. sed -i "s|#net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
  173. sed -i "s|net.ipv4.conf.all.secure_redirects.*|net.ipv4.conf.all.secure_redirects = 0|g" /etc/sysctl.conf
  174. fi
  175. if ! grep -q "net.ipv4.conf.default.accept_source_route" /etc/sysctl.conf; then
  176. echo "net.ipv4.conf.default.accept_source_route = 0" >> /etc/sysctl.conf
  177. else
  178. sed -i "s|# net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
  179. sed -i "s|#net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
  180. sed -i "s|net.ipv4.conf.default.accept_source_route.*|net.ipv4.conf.default.accept_source_route = 0|g" /etc/sysctl.conf
  181. fi
  182. if ! grep -q "net.ipv4.conf.default.secure_redirects" /etc/sysctl.conf; then
  183. echo "net.ipv4.conf.default.secure_redirects = 0" >> /etc/sysctl.conf
  184. else
  185. sed -i "s|# net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
  186. sed -i "s|#net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
  187. sed -i "s|net.ipv4.conf.default.secure_redirects.*|net.ipv4.conf.default.secure_redirects = 0|g" /etc/sysctl.conf
  188. fi
  189. if ! grep -q "net.ipv4.conf.default.accept_redirects" /etc/sysctl.conf; then
  190. echo "net.ipv4.conf.default.accept_redirects = 0" >> /etc/sysctl.conf
  191. else
  192. sed -i "s|# net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
  193. sed -i "s|#net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
  194. sed -i "s|net.ipv4.conf.default.accept_redirects.*|net.ipv4.conf.default.accept_redirects = 0|g" /etc/sysctl.conf
  195. fi
  196. mark_completed $FUNCNAME
  197. }
  198. function mesh_firewall {
  199. FIREWALL_FILENAME=${rootdir}/etc/systemd/system/meshfirewall.service
  200. MESH_FIREWALL_SCRIPT=${rootdir}/usr/bin/mesh-firewall
  201. echo '#!/bin/bash' > $MESH_FIREWALL_SCRIPT
  202. echo 'iptables -P INPUT ACCEPT' >> $MESH_FIREWALL_SCRIPT
  203. echo 'ip6tables -P INPUT ACCEPT' >> $MESH_FIREWALL_SCRIPT
  204. echo 'iptables -F' >> $MESH_FIREWALL_SCRIPT
  205. echo 'ip6tables -F' >> $MESH_FIREWALL_SCRIPT
  206. echo 'iptables -t nat -F' >> $MESH_FIREWALL_SCRIPT
  207. echo 'ip6tables -t nat -F' >> $MESH_FIREWALL_SCRIPT
  208. echo 'iptables -X' >> $MESH_FIREWALL_SCRIPT
  209. echo 'ip6tables -X' >> $MESH_FIREWALL_SCRIPT
  210. echo 'iptables -P INPUT DROP' >> $MESH_FIREWALL_SCRIPT
  211. echo 'ip6tables -P INPUT DROP' >> $MESH_FIREWALL_SCRIPT
  212. echo 'iptables -A INPUT -i lo -j ACCEPT' >> $MESH_FIREWALL_SCRIPT
  213. echo 'iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT' >> $MESH_FIREWALL_SCRIPT
  214. echo '' >> $MESH_FIREWALL_SCRIPT
  215. echo '# Make sure incoming tcp connections are SYN packets' >> $MESH_FIREWALL_SCRIPT
  216. echo 'iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP' >> $MESH_FIREWALL_SCRIPT
  217. echo '' >> $MESH_FIREWALL_SCRIPT
  218. echo '# Drop packets with incoming fragments' >> $MESH_FIREWALL_SCRIPT
  219. echo 'iptables -A INPUT -f -j DROP' >> $MESH_FIREWALL_SCRIPT
  220. echo '' >> $MESH_FIREWALL_SCRIPT
  221. echo '# Drop bogons' >> $MESH_FIREWALL_SCRIPT
  222. echo 'iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP' >> $MESH_FIREWALL_SCRIPT
  223. echo 'iptables -A INPUT -p tcp --tcp-flags ALL FIN,PSH,URG -j DROP' >> $MESH_FIREWALL_SCRIPT
  224. echo 'iptables -A INPUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP' >> $MESH_FIREWALL_SCRIPT
  225. echo '' >> $MESH_FIREWALL_SCRIPT
  226. echo '# Incoming malformed NULL packets:' >> $MESH_FIREWALL_SCRIPT
  227. echo 'iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP' >> $MESH_FIREWALL_SCRIPT
  228. echo '' >> $MESH_FIREWALL_SCRIPT
  229. echo "iptables -A INPUT -p tcp --dport $TOX_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  230. echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport $ZERONET_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  231. echo "iptables -A INPUT -i $WIFI_INTERFACE -p tcp --dport $ZERONET_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  232. echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport $TRACKER_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  233. echo "iptables -A INPUT -i $WIFI_INTERFACE -p tcp --dport $TRACKER_PORT -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  234. echo "iptables -A INPUT -i $WIFI_INTERFACE -p udp --dport 1900 -j ACCEPT" >> $MESH_FIREWALL_SCRIPT
  235. chmod +x $MESH_FIREWALL_SCRIPT
  236. echo '[Unit]' > $FIREWALL_FILENAME
  237. echo 'Description=Mesh Firewall' >> $FIREWALL_FILENAME
  238. echo '' >> $FIREWALL_FILENAME
  239. echo '[Service]' >> $FIREWALL_FILENAME
  240. echo 'Type=oneshot' >> $FIREWALL_FILENAME
  241. echo 'ExecStart=/usr/bin/mesh-firewall' >> $FIREWALL_FILENAME
  242. echo 'RemainAfterExit=no' >> $FIREWALL_FILENAME
  243. echo '' >> $FIREWALL_FILENAME
  244. echo 'TimeoutSec=30' >> $FIREWALL_FILENAME
  245. echo '' >> $FIREWALL_FILENAME
  246. echo '[Install]' >> $FIREWALL_FILENAME
  247. echo 'WantedBy=multi-user.target' >> $FIREWALL_FILENAME
  248. chmod +x $FIREWALL_FILENAME
  249. chroot "$rootdir" systemctl enable meshfirewall
  250. }
  251. function firewall_add {
  252. firewall_name=$(echo "$1" | sed "s| |-|g")
  253. firewall_port=$2
  254. firewall_protocol="$3"
  255. if ! grep -q "${firewall_name}=${firewall_port}" $FIREWALL_CONFIG; then
  256. echo "${firewall_name}=${firewall_port}" >> $FIREWALL_CONFIG
  257. if [ ! ${firewall_protocol} ]; then
  258. iptables -A INPUT -p udp --dport ${firewall_port} -j ACCEPT
  259. iptables -A INPUT -p tcp --dport ${firewall_port} -j ACCEPT
  260. else
  261. if [[ "${firewall_protocol}" == *"udp"* ]]; then
  262. iptables -A INPUT -p udp --dport ${firewall_port} -j ACCEPT
  263. fi
  264. if [[ "${firewall_protocol}" == *"tcp"* ]]; then
  265. iptables -A INPUT -p tcp --dport ${firewall_port} -j ACCEPT
  266. fi
  267. fi
  268. save_firewall_settings
  269. fi
  270. }
  271. function firewall_add_range {
  272. firewall_name=$(echo "$1" | sed "s| |-|g")
  273. firewall_port_start=$2
  274. firewall_port_end=$3
  275. firewall_protocol="$4"
  276. if ! grep -q "${firewall_name}=${firewall_port_start}:${firewall_port_end}" $FIREWALL_CONFIG; then
  277. echo "${firewall_name}=${firewall_port_start}:${firewall_port_end}" >> $FIREWALL_CONFIG
  278. if [ ! ${firewall_protocol} ]; then
  279. iptables -A INPUT -p udp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
  280. iptables -A INPUT -p tcp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
  281. else
  282. if [[ "${firewall_protocol}" == *"udp"* ]]; then
  283. iptables -A INPUT -p udp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
  284. fi
  285. if [[ "${firewall_protocol}" == *"tcp"* ]]; then
  286. iptables -A INPUT -p tcp --dport ${firewall_port_start}:${firewall_port_end} -j ACCEPT
  287. fi
  288. fi
  289. save_firewall_settings
  290. fi
  291. }
  292. function firewall_remove {
  293. firewall_port=$1
  294. firewall_protocol="$2"
  295. if [ ! -f $FIREWALL_CONFIG ]; then
  296. return
  297. fi
  298. if grep -q "=${firewall_port}" $FIREWALL_CONFIG; then
  299. if [ ! ${firewall_protocol} ]; then
  300. iptables -D INPUT -p udp --dport ${firewall_port} -j ACCEPT
  301. iptables -D INPUT -p tcp --dport ${firewall_port} -j ACCEPT
  302. else
  303. if [[ "${firewall_protocol}" == *"udp"* ]]; then
  304. iptables -D INPUT -p udp --dport ${firewall_port} -j ACCEPT
  305. fi
  306. if [[ "${firewall_protocol}" == *"tcp"* ]]; then
  307. iptables -D INPUT -p tcp --dport ${firewall_port} -j ACCEPT
  308. fi
  309. fi
  310. sed -i "/=${firewall_port}/d" $FIREWALL_CONFIG
  311. save_firewall_settings
  312. fi
  313. }
  314. # NOTE: deliberately no exit 0