jailsetup.sh

   1 #!/bin/sh
   2 # The Girocco jail setup script
   3 #
   4 # If the first parameter is "dbonly", setup the database only
   5 #
   6 # We are designed to set up the chroot based on the output of
   7 # `uname -s` by sourcing a suitable system-specific script.
   8 # Unrecognized systems will generate an error.  When using
   9 # "dbonly" the setup of the chroot binaries is skipped so the
  10 # output of `uname -s` does not matter in that case.
  11
  12 set -e
  13
  14 curdir="`pwd`"
  15 srcdir="$curdir/src"
  16 getent="$srcdir/getent"
  17 . ./shlib.sh
  18
  19 dbonly=''
  20 [ "$1" != "dbonly" ] || dbonly=1
  21
  22 reserved_users="root sshd _sshd mob git lock bundle nobody everyone $cfg_cgi_user $cfg_mirror_user"
  23
  24 # Require either sshd or _sshd user unless "dbonly"
  25 sshd_user=sshd
  26 if ! "$getent" passwd sshd >/dev/null && ! "$getent" passwd _sshd >/dev/null; then
  27         if [ -n "$dbonly" ]; then
  28                 if [ ! -s etc/passwd ]; then
  29                         # Only complain on initial etc/passwd creation
  30                         echo "WARNING: no sshd or _sshd user, omitting entries from chroot etc/passwd"
  31                 fi
  32                 sshd_user=
  33         else
  34                 echo "*** Error: You do not have required sshd or _sshd user in system." >&2
  35                 exit 1
  36         fi
  37 else
  38         "$getent" passwd sshd >/dev/null || sshd_user=_sshd
  39 fi
  40
  41 # Verify we have all we need
  42 if ! "$getent" passwd "$cfg_mirror_user" >/dev/null; then
  43         echo "*** Error: You do not have \"$cfg_mirror_user\" user in system yet." >&2
  44         exit 1
  45 fi
  46 if ! "$getent" passwd "$cfg_cgi_user" >/dev/null; then
  47         echo "*** Error: You do not have \"$cfg_cgi_user\" user in system yet." >&2
  48         exit 1
  49 fi
  50 if [ -n "$dbonly" -a -z "$cfg_owning_group" ]; then
  51         cfg_owning_group="$("$getent" passwd "$cfg_mirror_user" | cut -d : -f 4)"
  52 elif ! "$getent" group "$cfg_owning_group" >/dev/null; then
  53         echo "*** Error: You do not have \"$cfg_owning_group\" group in system yet." >&2
  54         exit 1
  55 fi
  56
  57 # One last paranoid check before we go writing all over everything
  58 if [ -z "$cfg_chroot" -o "$cfg_chroot" = "/" ]; then
  59         echo "*** Error: chroot location is not set or is invalid." >&2
  60         echo "*** Error: perhaps you have an incorrect Config.pm?" >&2
  61         exit 1
  62 fi
  63
  64 umask 022
  65 mkdir -p "$cfg_chroot"
  66 cd "$cfg_chroot"
  67 chmod 755 "$cfg_chroot" ||
  68         echo "WARNING: Cannot chmod $cfg_chroot"
  69
  70 mkdir -p var/empty
  71 chmod 0555 var/empty ||
  72         echo "WARNING: Cannot chmod a=rx $cfg_chroot/var/empty"
  73
  74 # Set up basic user/group configuration; if there isn't any already
  75 mobpass=''
  76 [ -n "$cfg_mob" ] || mobpass='x'
  77 mkdir -p etc
  78 if [ ! -s etc/passwd ]; then
  79         cat >etc/passwd <<EOT
  80 root:x:0:0:system administrator:/var/empty:/bin/false
  81 nobody:x:$("$getent" passwd nobody | cut -d : -f 3-4):unprivileged user:/var/empty:/bin/false
  82 EOT
  83         [ -z "$sshd_user" ] || cat >>etc/passwd <<EOT
  84 sshd:x:$("$getent" passwd $sshd_user | cut -d : -f 3-4):privilege separation:/var/empty:/bin/false
  85 _sshd:x:$("$getent" passwd $sshd_user | cut -d : -f 3-4):privilege separation:/var/empty:/bin/false
  86 EOT
  87         [ "$cfg_cgi_user" = "$cfg_mirror_user" ] || cat >>etc/passwd <<EOT
  88 $cfg_cgi_user:x:$("$getent" passwd "$cfg_cgi_user" | cut -d : -f 3-5):/:/bin/true
  89 EOT
  90         cat >>etc/passwd <<EOT
  91 $cfg_mirror_user:x:$("$getent" passwd "$cfg_mirror_user" | cut -d : -f 3-5):/:/bin/true
  92 everyone:x:65537:$("$getent" group "$cfg_owning_group" | cut -d : -f 3):every user:/:/bin/false
  93 mob:$mobpass:65538:$("$getent" group "$cfg_owning_group" | cut -d : -f 3):the mob:/:/bin/git-shell-verify
  94 git::65539:$("$getent" passwd nobody | cut -d : -f 4):read-only access:/:/bin/git-shell-verify
  95 EOT
  96 elif [ -z "$dbonly" ]; then
  97         # Make sure an sshd entry is present
  98         if ! grep -q '^sshd:' etc/passwd; then
  99                 echo "*** Error: chroot etc/passwd exists but lacks sshd entry." >&2
 100                 exit 1
 101         fi
 102 fi
 103
 104 if [ ! -s etc/group ]; then
 105         cat >etc/group <<EOT
 106 _repo:x:$("$getent" group "$cfg_owning_group" | cut -d : -f 3):$cfg_mirror_user
 107 EOT
 108 fi
 109
 110 # Set up basic default Git configuration
 111 # Initialize one if none exists or update critical variables for an existing one
 112 mkdir -p etc/girocco
 113 didchmod=
 114 if [ -e etc/girocco/.gitconfig ] && ! [ -f etc/girocco/.gitconfig ]; then
 115         echo "*** Error: chroot etc/girocco/.gitconfig exists but is not a file." >&2
 116         exit 1
 117 fi
 118 if [ -f etc/girocco/.gitconfig ]; then
 119         gcerr=0
 120         x="$(git config --file etc/girocco/.gitconfig --get "no--such--section.no  such  subsection.no--such--key")" || gcerr=$?
 121         if [ $gcerr -gt 1 ]; then
 122                 echo "*** Error: chroot etc/girocco/.gitconfig exists but is corrupt." >&2
 123                 echo "*** Error: either remove it or edit it to correct the problem." >&2
 124                 exit 1
 125         fi
 126 fi
 127 if [ ! -s etc/girocco/.gitconfig ]; then
 128         chmod u+w etc/girocco
 129         didchmod=1
 130         cat >etc/girocco/.gitconfig <<EOT
 131 # Any values set here will take effect whenever Girocco runs a git command
 132
 133 EOT
 134 fi
 135 # $1 => name, $2 => value, $3 => overwrite_flag
 136 update_config_item() {
 137         _existsnot=
 138         _oldval=
 139         _oldval="$(git config --file etc/girocco/.gitconfig --get "$1")" || _existsnot=1
 140         if [ -z "$_existsnot" ]; then
 141                 [ -n "$3" ] || return 0
 142                 [ "$_oldval" != "$2" ] || return 0
 143         fi
 144         [ -n "$didchmod" ] || { chmod u+w etc/girocco; didchmod=1; }
 145         git config --file etc/girocco/.gitconfig "$1" "$2"
 146         if [ -n "$_existsnot" ]; then
 147                 echo "chroot: etc/girocco/.gitconfig: config $1: (created) \"$2\""
 148         else
 149                 echo "chroot: etc/girocco/.gitconfig: config $1: \"$_oldval\" -> \"$2\""
 150         fi
 151 }
 152 if [ -n "$cfg_git_no_mmap" ]; then
 153         update_config_item core.packedGitWindowSize 1m 1
 154 else
 155         update_config_item core.packedGitWindowSize 32m 1
 156 fi
 157 if [ -n "$var_window_memory" ]; then
 158         update_config_item pack.windowMemory "$var_window_memory" 1
 159 fi
 160 if [ -n "$cfg_jgit_compatible_bitmaps" ]; then
 161         update_config_item pack.writeBitmapHashCache false 1
 162 else
 163         update_config_item pack.writeBitmapHashCache true 1
 164 fi
 165 update_config_item http.lowSpeedLimit 1
 166 update_config_item http.lowSpeedTime 600
 167 [ -z "$didchmod" ] || chmod a-w etc/girocco
 168
 169 mkdir -p etc/sshkeys etc/sshcerts etc/sshactive
 170 for ruser in $reserved_users; do
 171         touch etc/sshkeys/$ruser
 172 done
 173 chgrp $cfg_owning_group etc etc/sshkeys etc/sshcerts etc/sshactive ||
 174         echo "WARNING: Cannot chgrp $cfg_owning_group the etc directories"
 175 chgrp $cfg_owning_group etc/passwd ||
 176         echo "WARNING: Cannot chgrp $cfg_owning_group $cfg_chroot/etc/passwd"
 177 chgrp $cfg_owning_group etc/group ||
 178         echo "WARNING: Cannot chgrp $cfg_owning_group $cfg_chroot/etc/group"
 179 chgrp $cfg_owning_group etc/girocco etc/girocco/.gitconfig ||
 180         echo "WARNING: Cannot chgrp $cfg_owning_group $cfg_chroot/etc/girocco"
 181 chmod g+s etc etc/sshkeys etc/sshcerts etc/sshactive ||
 182         echo "WARNING: Cannot chmod g+s the etc directories"
 183 chmod g+w etc etc/sshkeys etc/sshcerts etc/sshactive ||
 184         echo "WARNING: Cannot chmod g+w the etc directories"
 185 chmod g+w etc/passwd etc/group ||
 186         echo "WARNING: Cannot chmod g+w the etc/passwd and/or etc/group files"
 187 chmod go-w etc/passwd etc/girocco etc/girocco/.gitconfig ||
 188         echo "WARNING: Cannot chmod go-w etc/girocco and/or etc/girocco/.gitconfig"
 189 chmod a-w etc/girocco ||
 190         echo "WARNING: Cannot chmod a-w etc/girocco"
 191 chmod -R g+w etc/sshkeys etc/sshcerts etc/sshactive 2>/dev/null ||
 192         echo "WARNING: Cannot chmod g+w the sshkeys, sshcerts and/or sshactive files"
 193
 194 # Note time of last install
 195 > etc/sshactive/_install
 196
 197 [ -z "$dbonly" ] || exit 0
 198
 199 # Make sure the system type is supported for chroot
 200 sysname="$(uname -s | tr A-Z a-z || :)"
 201 : ${sysname:=linux}
 202 nosshdir=
 203 # These equivalents may need to be expanded at some point
 204 case "$sysname" in
 205         *kfreebsd*)
 206                 sysname=linux;;
 207         *darwin*)
 208                 sysname=darwin;;
 209         *dragonfly*)
 210                 sysname=dragonfly;;
 211         *freebsd*)
 212                 sysname=freebsd;;
 213         *linux*)
 214                 sysname=linux;;
 215 esac
 216
 217 chrootsetup="$curdir/chrootsetup_$sysname.sh"
 218 if ! [ -r "$chrootsetup" -a -s "$chrootsetup" ]; then
 219         echo "*** Error: $chrootsetup not found" >&2
 220         echo "*** Error: creating a chroot for a `uname -s` system is not supported" >&2
 221         exit 1
 222 fi
 223
 224 # validate reporoot, chroot and jailreporoot before doing anything more
 225
 226 # validates the passed in dir if a second argument is not empty dir must NOT
 227 # start with / otherwise it must.  A trailing '/' is removed and any duplicated
 228 # // are removed and a sole / or empty is disallowed.
 229 make_valid_dir() {
 230         _check="$(echo "$1" | tr -s /)"
 231         _check="${_check%/}"
 232         [ -z "$_check" -o "$_check" = "/" ] && return 1
 233         if [ -z "$2" ]; then
 234                 # must start with '/'
 235                 case "$_check" in /*) :;; *) return 1; esac
 236         else
 237                 # must NOT start with '/'
 238                 case "$_check" in /*) return 1; esac
 239         fi
 240         echo "$_check"
 241 }
 242
 243 if ! reporoot="$(make_valid_dir "$cfg_reporoot")"; then
 244         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 245         echo "*** Error: MUST start with '/' and MUST NOT be '/'" >&2
 246         exit 1
 247 fi
 248 if ! chroot="$(make_valid_dir "$cfg_chroot")"; then
 249         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 250         echo "*** Error: MUST start with '/' and MUST NOT be '/'" >&2
 251         exit 1
 252 fi
 253 if ! jailreporoot="$(make_valid_dir "$cfg_jailreporoot" 1)"; then
 254         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 255         echo "*** Error: MUST NOT start with '/' and MUST NOT be ''" >&2
 256         exit 1
 257 fi
 258
 259 # chroot MUST NOT be reporoot
 260 if [ "$chroot" = "$reporoot" ]; then
 261         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 262         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 263         echo "*** Error: reporoot and chroot MUST NOT be the same" >&2
 264         exit 1
 265 fi
 266
 267 # chroot MUST NOT be a subdirectory of reporoot
 268 case "$chroot" in "$reporoot"/*)
 269         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 270         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 271         echo "*** Error: chroot MUST NOT be a subdirectory of reporoot" >&2
 272         exit 1
 273 esac
 274
 275 # chroot/jailreporoot MUST NOT be a subdirectory of reporoot
 276 case "$chroot/$jailreporoot" in "$reporoot"/*)
 277         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 278         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 279         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 280         echo "*** Error: chroot/jailreporoot MUST NOT be a subdirectory of reporoot" >&2
 281         exit 1
 282 esac
 283
 284 # reporoot MUST NOT be a subdirectory of chroot/jailreporoot
 285 case "$reporoot" in "$chroot/$jailreporoot"/*)
 286         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 287         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 288         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 289         echo "*** Error: reporoot MUST NOT be a subdirectory of chroot/jailreporoot" >&2
 290         exit 1
 291 esac
 292
 293 # Set the user and group on the top of the chroot before creating anything else
 294 chown 0:0 "$chroot"
 295
 296 # When we create a fork, the alternates always have an absolute path.
 297 # If reporoot is not --bind mounted at the same location in chroot we must
 298 # create a suitable symlink so the absolute path alternates continue to work
 299 # in the ssh chroot or else forks will be broken in there.
 300 if [ "$reporoot" != "/$jailreporoot" ]; then
 301         mkdirp="$(dirname "${reporoot#/}")"
 302         [ "$mkdirp" = "." ] && mkdirp=
 303         lnback=
 304         [ -z "$mkdirp" ] || lnback="$(echo "$mkdirp/" | sed -e 's,[^/]*/,../,g')"
 305         [ -z "$mkdirp" ] || mkdir -p "$chroot/$mkdirp"
 306         (umask 0; ln -s -f -n "$lnback$jailreporoot" "$chroot$reporoot")
 307         [ $? -eq 0 ] || exit 1
 308 fi
 309
 310 # First, setup basic platform-independent directory structure
 311 mkdir -p bin dev etc lib sbin var/empty var/run "$jailreporoot"
 312 chmod 0555 var/empty
 313 rm -rf usr local
 314 ln -s . usr
 315 ln -s . local
 316
 317 # Now source the platform-specific script that is responsible for dev device
 318 # setup, proc setup (if needed), lib64 setup (if needed) and basic library
 319 # installation to make a chroot operational.  Additionally it will define a
 320 # pull_in_bin function that can be used to add executables and their library
 321 # dependencies to the chroot and finally will install a suitable nc.openbsd
 322 # compatible version of netcat that supports connections to unix sockets.
 323 . "$chrootsetup"
 324
 325 # Now, bring in sshd, sh etc.
 326 # The $chrootsetup script should have already provided a suitable nc.openbsd
 327 install -p "$cfg_basedir/bin/git-shell-verify" bin/git-shell-verify.new
 328 install -p "$cfg_basedir/bin/git-askpass-password" bin/git-askpass-password.new
 329 perl -i -p \
 330         -e 's|^#!.*|#!/bin/sh| if $. == 1;' \
 331         -e 'close ARGV if eof;' \
 332         bin/git-shell-verify.new bin/git-askpass-password.new
 333 mv -f bin/git-askpass-password.new bin/git-askpass-password
 334 mv -f bin/git-shell-verify.new bin/git-shell-verify
 335 pull_in_bin "$cfg_basedir/bin/can_user_push" bin
 336 pull_in_bin "$cfg_basedir/bin/list_packs" bin
 337 pull_in_bin "$var_sh_bin" bin/sh
 338 pull_in_bin /bin/chmod bin
 339 pull_in_bin /bin/date bin
 340 pull_in_bin /bin/mkdir bin
 341 pull_in_bin /bin/mv bin
 342 pull_in_bin /bin/rm bin
 343 pull_in_bin /bin/sleep bin
 344 pull_in_bin /usr/bin/find bin
 345 pull_in_bin /usr/bin/touch bin
 346 pull_in_bin /usr/bin/wc bin
 347 pull_in_bin /usr/bin/xargs bin
 348 pull_in_bin /usr/sbin/sshd sbin
 349
 350 # ...and the bits of git we need,
 351 # being sure to use the configured git and its --exec-path to find the pieces
 352 for i in git git-index-pack git-receive-pack git-shell git-update-server-info git-upload-archive \
 353         git-upload-pack git-unpack-objects git-config git-for-each-ref git-rev-list; do
 354         pull_in_bin "$var_git_exec_path/$i" bin git
 355 done
 356
 357 # Note time of last jailsetup
 358 > etc/sshactive/_jailsetup
 359
 360 # Update permissions on the database files
 361 chown $cfg_cgi_user:$cfg_owning_group etc/passwd etc/group
 362 chown -R $cfg_cgi_user:$cfg_owning_group etc/sshkeys etc/sshcerts etc/sshactive
 363 chown $cfg_mirror_user:$cfg_owning_group etc etc/girocco etc/girocco/.gitconfig
 364
 365 # Set up basic sshd configuration:
 366 if [ -n "$nosshdir" ]; then
 367         rm -rf etc/ssh
 368         ln -s . etc/ssh
 369         [ ! -f /etc/moduli ] || { cp -p /etc/moduli etc/; chown 0:0 etc/moduli; }
 370 else
 371         [ ! -e etc/ssh -o -d etc/ssh ] || rm -rf etc/ssh
 372         mkdir -p etc/ssh
 373         [ ! -f /etc/ssh/moduli ] || { cp -p /etc/ssh/moduli etc/ssh/; chown 0:0 etc/ssh/moduli; }
 374 fi
 375 mkdir -p var/run/sshd
 376 if [ ! -s etc/ssh/sshd_config ]; then
 377         cat >etc/ssh/sshd_config <<EOT
 378 Protocol                2
 379 Port                    $cfg_sshd_jail_port
 380 UsePAM                  no
 381 X11Forwarding           no
 382 AllowAgentForwarding    no
 383 AllowTcpForwarding      no
 384 PermitTunnel            no
 385 IgnoreUserKnownHosts    yes
 386 PrintLastLog            no
 387 PrintMotd               no
 388 UseDNS                  no
 389 PermitRootLogin         no
 390 UsePrivilegeSeparation  yes
 391
 392 HostKey                 /etc/ssh/ssh_host_rsa_key
 393 EOT
 394 if [ -z "$cfg_disable_dsa" ]; then
 395         cat >>etc/ssh/sshd_config <<EOT
 396 HostKey                 /etc/ssh/ssh_host_dsa_key
 397 EOT
 398 fi
 399         cat >>etc/ssh/sshd_config <<EOT
 400 AuthorizedKeysFile      /etc/sshkeys/%u
 401 StrictModes             no
 402
 403 # mob and git users:
 404 PermitEmptyPasswords    yes
 405 ChallengeResponseAuthentication no
 406 PasswordAuthentication  yes
 407 EOT
 408 fi
 409 if [ ! -s etc/ssh/ssh_host_rsa_key ]; then
 410         bits=2048
 411         if [ "$cfg_rsakeylength" -gt "$bits" ] 2>/dev/null; then
 412                 bits="$cfg_rsakeylength"
 413         fi
 414         yes | ssh-keygen -b "$bits" -t rsa -N "" -C Girocco -f etc/ssh/ssh_host_rsa_key
 415 fi
 416 if [ -z "$cfg_disable_dsa" -a ! -s etc/ssh/ssh_host_dsa_key ]; then
 417         # ssh-keygen can only create 1024 bit DSA keys
 418         yes | ssh-keygen -b 1024 -t dsa -N "" -C Girocco -f etc/ssh/ssh_host_dsa_key
 419 fi
 420
 421 # Set the final permissions on the binaries and perform any final twiddling
 422 chroot_update_permissions
 423
 424 # Change the owner of the sshd-related files
 425 chown 0:0 etc/ssh/ssh_* etc/ssh/sshd_*
 426
 427 echo "--- Add to your boot scripts: mount --bind $reporoot $chroot/$jailreporoot"
 428 echo "--- Add to your boot scripts: mount --bind /proc $chroot/proc"
 429 echo "--- Add to your syslog configuration: listening on socket $chroot/dev/log"
 430 echo "--- To restart a running jail's sshd: sudo kill -HUP \`cat $chroot/var/run/sshd.pid\`"