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