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         *freebsd*)
 204                 sysname=freebsd;;
 205         *linux*)
 206                 sysname=linux;;
 207 esac
 208
 209 chrootsetup="$curdir/chrootsetup_$sysname.sh"
 210 if ! [ -r "$chrootsetup" -a -s "$chrootsetup" ]; then
 211         echo "*** Error: $chrootsetup not found" >&2
 212         echo "*** Error: creating a chroot for a `uname -s` system is not supported" >&2
 213         exit 1
 214 fi
 215
 216 # validate reporoot, chroot and jailreporoot before doing anything more
 217
 218 # validates the passed in dir if a second argument is not empty dir must NOT
 219 # start with / otherwise it must.  A trailing '/' is removed and any duplicated
 220 # // are removed and a sole / or empty is disallowed.
 221 make_valid_dir() {
 222         _check="$(echo "$1" | tr -s /)"
 223         _check="${_check%/}"
 224         [ -z "$_check" -o "$_check" = "/" ] && return 1
 225         if [ -z "$2" ]; then
 226                 # must start with '/'
 227                 case "$_check" in /*) :;; *) return 1; esac
 228         else
 229                 # must NOT start with '/'
 230                 case "$_check" in /*) return 1; esac
 231         fi
 232         echo "$_check"
 233 }
 234
 235 if ! reporoot="$(make_valid_dir "$cfg_reporoot")"; then
 236         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 237         echo "*** Error: MUST start with '/' and MUST NOT be '/'" >&2
 238         exit 1
 239 fi
 240 if ! chroot="$(make_valid_dir "$cfg_chroot")"; then
 241         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 242         echo "*** Error: MUST start with '/' and MUST NOT be '/'" >&2
 243         exit 1
 244 fi
 245 if ! jailreporoot="$(make_valid_dir "$cfg_jailreporoot" 1)"; then
 246         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 247         echo "*** Error: MUST NOT start with '/' and MUST NOT be ''" >&2
 248         exit 1
 249 fi
 250
 251 # chroot MUST NOT be reporoot
 252 if [ "$chroot" = "$reporoot" ]; then
 253         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 254         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 255         echo "*** Error: reporoot and chroot MUST NOT be the same" >&2
 256         exit 1
 257 fi
 258
 259 # chroot MUST NOT be a subdirectory of reporoot
 260 case "$chroot" in "$reporoot"/*)
 261         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 262         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 263         echo "*** Error: chroot MUST NOT be a subdirectory of reporoot" >&2
 264         exit 1
 265 esac
 266
 267 # chroot/jailreporoot MUST NOT be a subdirectory of reporoot
 268 case "$chroot/$jailreporoot" in "$reporoot"/*)
 269         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 270         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 271         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 272         echo "*** Error: chroot/jailreporoot MUST NOT be a subdirectory of reporoot" >&2
 273         exit 1
 274 esac
 275
 276 # reporoot MUST NOT be a subdirectory of chroot/jailreporoot
 277 case "$reporoot" in "$chroot/$jailreporoot"/*)
 278         echo "*** Error: invalid Config::reporoot: $cfg_reporoot" >&2
 279         echo "*** Error: invalid Config::chroot: $cfg_chroot" >&2
 280         echo "*** Error: invalid Config::jailreporoot: $cfg_jailreporoot" >&2
 281         echo "*** Error: reporoot MUST NOT be a subdirectory of chroot/jailreporoot" >&2
 282         exit 1
 283 esac
 284
 285 # Set the user and group on the top of the chroot before creating anything else
 286 chown 0:0 "$chroot"
 287
 288 # When we create a fork, the alternates always have an absolute path.
 289 # If reporoot is not --bind mounted at the same location in chroot we must
 290 # create a suitable symlink so the absolute path alternates continue to work
 291 # in the ssh chroot or else forks will be broken in there.
 292 if [ "$reporoot" != "/$jailreporoot" ]; then
 293         mkdirp="$(dirname "${reporoot#/}")"
 294         [ "$mkdirp" = "." ] && mkdirp=
 295         lnback=
 296         [ -z "$mkdirp" ] || lnback="$(echo "$mkdirp/" | sed -e 's,[^/]*/,../,g')"
 297         [ -z "$mkdirp" ] || mkdir -p "$chroot/$mkdirp"
 298         (umask 0; ln -s -f -n "$lnback$jailreporoot" "$chroot$reporoot")
 299         [ $? -eq 0 ] || exit 1
 300 fi
 301
 302 # First, setup basic platform-independent directory structure
 303 mkdir -p bin dev etc lib sbin var/empty var/run "$jailreporoot"
 304 chmod 0555 var/empty
 305 rm -rf usr local
 306 ln -s . usr
 307 ln -s . local
 308
 309 # Now source the platform-specific script that is responsible for dev device
 310 # setup, proc setup (if needed), lib64 setup (if needed) and basic library
 311 # installation to make a chroot operational.  Additionally it will define a
 312 # pull_in_bin function that can be used to add executables and their library
 313 # dependencies to the chroot and finally will install a suitable nc.openbsd
 314 # compatible version of netcat that supports connections to unix sockets.
 315 . "$chrootsetup"
 316
 317 # Now, bring in sshd, sh etc.
 318 # The $chrootsetup script should have already provided a suitable nc.openbsd
 319 install -p "$cfg_basedir/bin/git-shell-verify" bin/git-shell-verify.new
 320 install -p "$cfg_basedir/bin/git-askpass-password" bin/git-askpass-password.new
 321 perl -i -p \
 322         -e 's|^#!.*|#!/bin/sh| if $. == 1;' \
 323         -e 'close ARGV if eof;' \
 324         bin/git-shell-verify.new bin/git-askpass-password.new
 325 mv -f bin/git-askpass-password.new bin/git-askpass-password
 326 mv -f bin/git-shell-verify.new bin/git-shell-verify
 327 pull_in_bin "$cfg_basedir/bin/can_user_push" bin
 328 pull_in_bin "$cfg_basedir/bin/list_packs" bin
 329 pull_in_bin "${cfg_posix_sh_bin:-/bin/sh}" bin/sh
 330 pull_in_bin /bin/chmod bin
 331 pull_in_bin /bin/date bin
 332 pull_in_bin /bin/mv bin
 333 pull_in_bin /bin/rm bin
 334 pull_in_bin /usr/bin/find bin
 335 pull_in_bin /usr/bin/touch bin
 336 pull_in_bin /usr/bin/xargs bin
 337 pull_in_bin /usr/sbin/sshd sbin
 338
 339 # ...and the bits of git we need,
 340 # being sure to use the configured git and its --exec-path to find the pieces
 341 for i in git git-index-pack git-receive-pack git-shell git-update-server-info git-upload-archive \
 342         git-upload-pack git-unpack-objects git-config git-for-each-ref git-rev-list; do
 343         pull_in_bin "$var_git_exec_path/$i" bin git
 344 done
 345
 346 # Note time of last jailsetup
 347 > etc/sshactive/_jailsetup
 348
 349 # Update permissions on the database files
 350 chown $cfg_cgi_user:$cfg_owning_group etc/passwd etc/group
 351 chown -R $cfg_cgi_user:$cfg_owning_group etc/sshkeys etc/sshcerts etc/sshactive
 352 chown $cfg_mirror_user:$cfg_owning_group etc etc/girocco etc/girocco/.gitconfig
 353
 354 # Set up basic sshd configuration:
 355 if [ -n "$nosshdir" ]; then
 356         rm -rf etc/ssh
 357         ln -s . etc/ssh
 358         [ ! -f /etc/moduli ] || { cp -p /etc/moduli etc/; chown 0:0 etc/moduli; }
 359 else
 360         [ ! -e etc/ssh -o -d etc/ssh ] || rm -rf etc/ssh
 361         mkdir -p etc/ssh
 362         [ ! -f /etc/ssh/moduli ] || { cp -p /etc/ssh/moduli etc/ssh/; chown 0:0 etc/ssh/moduli; }
 363 fi
 364 mkdir -p var/run/sshd
 365 if [ ! -s etc/ssh/sshd_config ]; then
 366         cat >etc/ssh/sshd_config <<EOT
 367 Protocol                2
 368 Port                    $cfg_sshd_jail_port
 369 UsePAM                  no
 370 X11Forwarding           no
 371 AllowAgentForwarding    no
 372 AllowTcpForwarding      no
 373 PermitTunnel            no
 374 IgnoreUserKnownHosts    yes
 375 PrintLastLog            no
 376 PrintMotd               no
 377 UseDNS                  no
 378 PermitRootLogin         no
 379 UsePrivilegeSeparation  yes
 380
 381 HostKey                 /etc/ssh/ssh_host_rsa_key
 382 EOT
 383 if [ -z "$cfg_disable_dsa" ]; then
 384         cat >>etc/ssh/sshd_config <<EOT
 385 HostKey                 /etc/ssh/ssh_host_dsa_key
 386 EOT
 387 fi
 388         cat >>etc/ssh/sshd_config <<EOT
 389 AuthorizedKeysFile      /etc/sshkeys/%u
 390 StrictModes             no
 391
 392 # mob user:
 393 PermitEmptyPasswords    yes
 394 ChallengeResponseAuthentication no
 395 PasswordAuthentication  yes
 396 EOT
 397 fi
 398 if [ ! -s etc/ssh/ssh_host_rsa_key ]; then
 399         bits=2048
 400         if [ "$cfg_rsakeylength" -gt "$bits" ] 2>/dev/null; then
 401                 bits="$cfg_rsakeylength"
 402         fi
 403         yes | ssh-keygen -b "$bits" -t rsa -N "" -C Girocco -f etc/ssh/ssh_host_rsa_key
 404 fi
 405 if [ -z "$cfg_disable_dsa" -a ! -s etc/ssh/ssh_host_dsa_key ]; then
 406         # ssh-keygen can only create 1024 bit DSA keys
 407         yes | ssh-keygen -b 1024 -t dsa -N "" -C Girocco -f etc/ssh/ssh_host_dsa_key
 408 fi
 409
 410 # Set the final permissions on the binaries and perform any final twiddling
 411 chroot_update_permissions
 412
 413 # Change the owner of the sshd-related files
 414 chown 0:0 etc/ssh/ssh_* etc/ssh/sshd_*
 415
 416 echo "--- Add to your boot scripts: mount --bind $reporoot $chroot/$jailreporoot"
 417 echo "--- Add to your boot scripts: mount --bind /proc $chroot/proc"
 418 echo "--- Add to your syslog configuration: listening on socket $chroot/dev/log"
 419 echo "--- To restart a running jail's sshd: sudo kill -HUP \`cat $chroot/var/run/sshd.pid\`"