* [Buildroot] [PATCH 2/3] packages: add ability for packages to create users
2012-12-30 23:26 [Buildroot] [pull request] Pull request for branch yem-package-create-user Yann E. MORIN
2012-12-30 23:26 ` [Buildroot] [PATCH 1/3] system/skeleton: add the shadow-group file Yann E. MORIN
@ 2012-12-30 23:26 ` Yann E. MORIN
2012-12-30 23:26 ` [Buildroot] [PATCH 3/3] package/tvheadend: use a non-root user to run the daemon Yann E. MORIN
2 siblings, 0 replies; 9+ messages in thread
From: Yann E. MORIN @ 2012-12-30 23:26 UTC (permalink / raw)
To: buildroot
Packages that install daemons may need those daemons to run as a non-root,
or an otherwise non-system (eg. 'daemon'), user.
Add infrastructure for packages to create users, by declaring the
FOO_USERS variable that conatin a makedev-syntax-like description
of the user(s) to add.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
docs/manual/adding-packages-generic.txt | 16 ++-
docs/manual/makedev-syntax.txt | 65 ++++++
fs/common.mk | 5 +-
package/pkg-generic.mk | 1 +
support/scripts/mkusers | 341 +++++++++++++++++++++++++++++++
5 files changed, 425 insertions(+), 3 deletions(-)
create mode 100755 support/scripts/mkusers
diff --git a/docs/manual/adding-packages-generic.txt b/docs/manual/adding-packages-generic.txt
index 0759d4f..1adf424 100644
--- a/docs/manual/adding-packages-generic.txt
+++ b/docs/manual/adding-packages-generic.txt
@@ -50,7 +50,11 @@ system is based on hand-written Makefiles or shell scripts.
34: /bin/foo f 4755 0 0 - - - - -
35: endef
36:
-37: $(eval $(generic-package))
+37: define LIBFOO_USERS
+38: foo -1 libfoo -1 * - - - LibFoo daemon
+39: endef
+40
+41: $(eval $(generic-package))
--------------------------------
The Makefile begins on line 6 to 10 with metadata information: the
@@ -95,7 +99,10 @@ On line 29..31, we define a device-node file used by this package
On line 33..35, we define the permissions to set to specific files
installed by this package (+LIBFOO_PERMISSIONS+).
-Finally, on line 37, we call the +generic-package+ function, which
+On lines 37..39, we define a user that is used by this package (eg.
+to run a daemon as non-root).
+
+Finally, on line 41, we call the +generic-package+ function, which
generates, according to the variables defined previously, all the
Makefile code necessary to make your package working.
@@ -252,6 +259,11 @@ information is (assuming the package name is +libfoo+) :
You can find some documentation for this syntax in the xref:makedev-syntax[].
This variable is optional.
+* +LIBFOO_USERS+ lists the users to create for this package, if it installs
+ a daemon you want to run with a specific user. The syntax is similar in
+ spirit to the makedevs one, and is described in the xref:makeuser-syntax[].
+ This variable is optional.
+
* +LIBFOO_LICENSE+ defines the license (or licenses) under which the package
is released.
This name will appear in the manifest file produced by +make legal-info+.
diff --git a/docs/manual/makedev-syntax.txt b/docs/manual/makedev-syntax.txt
index 27517b3..fffdac9 100644
--- a/docs/manual/makedev-syntax.txt
+++ b/docs/manual/makedev-syntax.txt
@@ -54,3 +54,68 @@ and then for device files corresponding to the partitions of
/dev/hda b 640 0 0 3 1 1 1 15
-------------------------------------------------------------------
+
+[[makeuser-syntax]]
+Makeuser syntax documentation
+-----------------------------
+
+The syntax to create users is inspired by the makedev syntax, above, but
+is psecific to buildroot.
+
+The syntax for adding a user is a space-separated list of fields, one
+user per-line; the fields are:
+
+|=================================================================
+|username |uid |group |gid |password |home |shell |groups |comment
+|=================================================================
+
+Where:
+
+- +username+ is the desired user name (aka login name) for the user.
+ It must be unique.
+- +uid+ is the desired UID for the user. It must be unique, and not
+ +0+. If set to +-1+, then a unique UID will be computed by buildroot.
+- +group+ is the desired name for the user's main group.
+- +gid+ is the desired GID for the user's main group. It must be unique,
+ and not +0+. If set to +-1+, then a unique GID will be computed by
+ buildroot.
+- +password+ is the crypt(3)-encrypted password. If prefixed with +=+,
+ then it is interpreted as clear-text, and will be cypt-encoded. If
+ prefixed with +!+, then login is disabled. If set to +*+, then login
+ is not allowed.
+- +home+ is the desired home directory for the user. If set to '-', no
+ home directory will be created, and the user's home will be +/+.
+ Explicitly setting +home+ to +/+ is not allowed.
+- +shell+ is the desired shell for the user. If set to +-+, then
+ +/bin/false+ is set as the user's shell.
+- +groups+ is the comma-separated list of additional groups the user
+ should be part of. If set to +-+, then the user will be a member of
+ no additional group.
+- +comment+ is an almost-free-form text.
+
+There are a few restrictions on the content of each field:
+
+* except for +comment+, all fields are mandatory.
+* except for +comment+, fields may not contain spaces.
+* no field may contain a column (+:+).
+
+If +home+ is not +-+, then the home directory, and all files below,
+will belong to the user and its main group.
+
+Example:
+
+----
+foo -1 bar -1 !=blabla /home/foo /bin/sh alpha,bravo Foo user
+----
+
+This will create this user:
+
+- +username+ (aka login name) is: +foo+
+- +uid+ is computed by buildroot
+- main +group+ is: +bar+
+- main group +gid+ is computed by buildroot
+- clear-text +password+ is: +blabla+, will be crypt(3)-encrypted, but login is disabled.
+- +home+ is: +/home/foo+
+- +shell+ is: +/bin/sh+
+- +foo+ is also a member of +groups+: +alpha+ and +bravo+
+- +comment+ is: +Foo user+
diff --git a/fs/common.mk b/fs/common.mk
index b1512dd..b5a7950 100644
--- a/fs/common.mk
+++ b/fs/common.mk
@@ -35,6 +35,7 @@ FAKEROOT_SCRIPT = $(BUILD_DIR)/_fakeroot.fs
FULL_DEVICE_TABLE = $(BUILD_DIR)/_device_table.txt
ROOTFS_DEVICE_TABLES = $(call qstrip,$(BR2_ROOTFS_DEVICE_TABLE)) \
$(call qstrip,$(BR2_ROOTFS_STATIC_DEVICE_TABLE))
+USERS_TABLE = $(BUILD_DIR)/_users_table.txt
define ROOTFS_TARGET_INTERNAL
@@ -55,11 +56,13 @@ endif
printf '$(subst $(sep),\n,$(PACKAGES_PERMISSIONS_TABLE))' >> $(FULL_DEVICE_TABLE)
echo "$(HOST_DIR)/usr/bin/makedevs -d $(FULL_DEVICE_TABLE) $(TARGET_DIR)" >> $(FAKEROOT_SCRIPT)
endif
+ printf '$(subst $(sep),\n,$(PACKAGES_USERS))' > $(USERS_TABLE)
+ $(TOPDIR)/support/scripts/mkusers $(USERS_TABLE) $(TARGET_DIR) >> $(FAKEROOT_SCRIPT)
echo "$(ROOTFS_$(2)_CMD)" >> $(FAKEROOT_SCRIPT)
chmod a+x $(FAKEROOT_SCRIPT)
$(HOST_DIR)/usr/bin/fakeroot -- $(FAKEROOT_SCRIPT)
cp support/misc/target-dir-warning.txt $(TARGET_DIR_WARNING_FILE)
- - at rm -f $(FAKEROOT_SCRIPT) $(FULL_DEVICE_TABLE)
+ - at rm -f $(FAKEROOT_SCRIPT) $(FULL_DEVICE_TABLE) $(USERS_TABLE)
$(foreach hook,$(ROOTFS_$(2)_POST_GEN_HOOKS),$(call $(hook))$(sep))
ifeq ($$(BR2_TARGET_ROOTFS_$(2)_GZIP),y)
gzip -9 -c $$@ > $$@.gz
diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
index a570ad7..871544c 100644
--- a/package/pkg-generic.mk
+++ b/package/pkg-generic.mk
@@ -510,6 +510,7 @@ ifeq ($$($$($(2)_KCONFIG_VAR)),y)
TARGETS += $(1)
PACKAGES_PERMISSIONS_TABLE += $$($(2)_PERMISSIONS)$$(sep)
PACKAGES_DEVICES_TABLE += $$($(2)_DEVICES)$$(sep)
+PACKAGES_USERS += $$($(2)_USERS)$$(sep)
ifeq ($$($(2)_SITE_METHOD),svn)
DL_TOOLS_DEPENDENCIES += svn
diff --git a/support/scripts/mkusers b/support/scripts/mkusers
new file mode 100755
index 0000000..ee922cd
--- /dev/null
+++ b/support/scripts/mkusers
@@ -0,0 +1,341 @@
+#!/bin/bash
+set -e
+myname="${0##*/}"
+
+#----------------------------------------------------------------------------
+# Configurable items
+MIN_UID=1000
+MAX_UID=1999
+MIN_GID=1000
+MAX_GID=1999
+# No more is configurable below this point
+#----------------------------------------------------------------------------
+
+#----------------------------------------------------------------------------
+USERS_TABLE="${1}"
+TARGET_DIR="${2}"
+shift 2
+PASSWD="${TARGET_DIR}/etc/passwd"
+SHADOW="${TARGET_DIR}/etc/shadow"
+GROUP="${TARGET_DIR}/etc/group"
+GSHADOW="${TARGET_DIR}/etc/gshadow"
+
+#----------------------------------------------------------------------------
+error() {
+ local fmt="${1}"
+ shift
+
+ printf "%s: " "${myname}" >&2
+ printf "${fmt}" "${@}" >&2
+}
+fail() {
+ error "$@"
+ exit 1
+}
+
+#----------------------------------------------------------------------------
+get_uid() {
+ local username="${1}"
+
+ grep -r -E "${username}:" "${PASSWD}" |cut -d: -f3
+}
+
+#----------------------------------------------------------------------------
+get_ugid() {
+ local username="${1}"
+
+ grep -r -E "${username}:" "${PASSWD}" |cut -d: -f4
+}
+
+#----------------------------------------------------------------------------
+get_gid() {
+ local group="${1}"
+
+ grep -r -E "${group}:" "${GROUP}" |cut -d: -f3
+}
+
+#----------------------------------------------------------------------------
+get_username() {
+ local uid="${1}"
+
+ sed -r -e '/^([^:]+):[^:]+:'"${uid}"':.*/!d; s//\1/;' "${PASSWD}"
+}
+
+#----------------------------------------------------------------------------
+get_group() {
+ local gid="${1}"
+
+ sed -r -e '/^([^:]+):[^:]+:'"${gid}"':/!d; s//\1/;' "${GROUP}"
+}
+
+#----------------------------------------------------------------------------
+get_ugroup() {
+ local username="${1}"
+ local ugid
+
+ ugid="$( get_ugid "${username}" )"
+ if [ -n "${ugid}" ]; then
+ get_group "${ugid}"
+ fi
+}
+
+#----------------------------------------------------------------------------
+# Sanity-check the new user/group:
+# - check the gid is not already used for another group
+# - check the group does not already exist with another gid
+# - check the user does not already exist with another gid
+# - check the uid is not already used for another user
+# - check the user does not already exist with another uid
+# - check the user does not already exist in another group
+check_user_validity() {
+ local username="${1}"
+ local uid="${2}"
+ local group="${3}"
+ local gid="${4}"
+ local _uid _ugid _gid _username _group _ugroup
+
+ _group="$( get_group "${gid}" )"
+ _gid="$( get_gid "${group}" )"
+ _ugid="$( get_ugid "${username}" )"
+ _username="$( get_username "${uid}" )"
+ _uid="$( get_uid "${username}" )"
+ _ugroup="$( get_ugroup "${username}" )"
+
+ if [ ${gid} -ge 0 ]; then
+ # check the gid is not already used for another group
+ if [ -n "${_group}" -a "${_group}" != "${group}" ]; then
+ fail "gid is already used by group '${_group}'\n"
+ fi
+
+ # check the group does not already exists with another gid
+ if [ -n "${_gid}" -a ${_gid} -ne ${gid} ]; then
+ fail "group already exists with gid '${_gid}'\n"
+ fi
+
+ # check the user does not already exists with another gid
+ if [ -n "${_ugid}" -a ${_ugid} -ne ${gid} ]; then
+ fail "user already exists with gid '${_ugid}'\n"
+ fi
+ fi
+
+ if [ ${uid} -ge 0 ]; then
+ # check the uid is not already used for another user
+ if [ -n "${_username}" -a "${_username}" != "${username}" ]; then
+ fail "uid is already used by user '${_username}'\n"
+ fi
+
+ # check the user does not already exists with another uid
+ if [ -n "${_uid}" -a ${_uid} -ne ${uid} ]; then
+ fail "user already exists with uid '${_uid}'\n"
+ fi
+ fi
+
+ # check the user does not already exist in another group
+ if [ -n "${_ugroup}" -a "${_ugroup}" != "${group}" ]; then
+ fail "user already exists with group '${_ugroup}'\n"
+ fi
+
+ return 0
+}
+
+#----------------------------------------------------------------------------
+# Generate a unique GID for given group. If the group already exists,
+# then simply report its current GID. Otherwise, generate the lowest GID
+# that is:
+# - not 0
+# - comprised in [MIN_GID..MAX_GID]
+# - not already used by a group
+generate_gid() {
+ local group="${1}"
+ local gid
+
+ gid="$( get_gid "${group}" )"
+ if [ -z "${gid}" ]; then
+ for(( gid=MIN_GID; gid<=MAX_GID; gid++ )); do
+ if [ -z "$( get_group "${gid}" )" ]; then
+ break
+ fi
+ done
+ if [ ${gid} -gt ${MAX_GID} ]; then
+ fail "can not allocate a GID for group '%s'\n" "${group}"
+ fi
+ fi
+ printf "%d\n" "${gid}"
+}
+
+#----------------------------------------------------------------------------
+# Add a group; if it does already exist, remove it first
+add_one_group() {
+ local group="${1}"
+ local gid="${2}"
+ local _f
+
+ # Generate a new GID if needed
+ if [ ${gid} -eq -1 ]; then
+ gid="$( generate_gid "${group}" )"
+ fi
+
+ # Remove any previous instance of this group
+ for _f in "${GROUP}" "${GSHADOW}"; do
+ sed -r -i -e '/^'"${group}"':.*/d;' "${_f}"
+ done
+
+ printf "%s:x:%d:\n" "${group}" "${gid}" >>"${GROUP}"
+ printf "%s:*::\n" "${group}" >>"${GSHADOW}"
+}
+
+#----------------------------------------------------------------------------
+# Generate a unique UID for given username. If the username already exists,
+# then simply report its current UID. Otherwise, generate the lowest UID
+# that is:
+# - not 0
+# - comprised in [MIN_UID..MAX_UID]
+# - not already used by a user
+generate_uid() {
+ local username="${1}"
+ local uid
+
+ uid="$( get_uid "${username}" )"
+ if [ -z "${uid}" ]; then
+ for(( uid=MIN_UID; uid<=MAX_UID; uid++ )); do
+ if [ -z "$( get_username "${uid}" )" ]; then
+ break
+ fi
+ done
+ if [ ${uid} -gt ${MAX_UID} ]; then
+ fail "can not allocate a UID for user '%s'\n" "${username}"
+ fi
+ fi
+ printf "%d\n" "${uid}"
+}
+
+#----------------------------------------------------------------------------
+# Add given user to given group, if not already the case
+add_user_to_group() {
+ local username="${1}"
+ local group="${2}"
+ local _f
+
+ for _f in "${GROUP}" "${GSHADOW}"; do
+ sed -r -i -e 's/^('"${group}"':.*:)(([^:]+,)?)'"${username}"'(,[^:]+*)?$/\1\2\4/;' \
+ -e 's/^('"${group}"':.*)$/\1,'"${username}"'/;' \
+ -e 's/,+/,/' \
+ -e 's/:,/:/' \
+ "${_f}"
+ done
+}
+
+#----------------------------------------------------------------------------
+# Add a user; if it does already exist, remove it first
+add_one_user() {
+ local username="${1}"
+ local uid="${2}"
+ local group="${3}"
+ local gid="${4}"
+ local passwd="${5}"
+ local home="${6}"
+ local shell="${7}"
+ local groups="${8}"
+ local comment="${9}"
+ local nb_days="$((($(date +%s)+(24*60*60-1))/(24*60*60)))"
+ local _f _group _home _shell _gid _passwd
+
+ # First, sanity-check the user
+ check_user_validity "${username}" "${uid}" "${group}" "${gid}"
+
+ # Generate a new UID if needed
+ if [ ${uid} -eq -1 ]; then
+ uid="$( generate_uid "${username}" )"
+ fi
+
+ # Remove any previous instance of this user
+ for _f in "${PASSWD}" "${SHADOW}"; do
+ sed -r -i -e '/^'"${username}"':.*/d;' "${_f}"
+ done
+
+ _gid="$( get_gid "${group}" )"
+ _shell="${shell}"
+ if [ "${shell}" = "-" ]; then
+ _shell="/bin/false"
+ fi
+ case "${home}" in
+ -) _home="/";;
+ /) fail "home can not be explicitly '/'\n";;
+ /*) _home="${home}";;
+ *) fail "home must be an absolute path";;
+ esac
+ case "${passwd}" in
+ =!*|!=*)
+ _passwd='!'"$( mkpasswd -m md5 "${passwd#??}" )"
+ ;;
+ =*)
+ _passwd="$( mkpasswd -m md5 "${passwd#?}" )"
+ ;;
+ *)
+ _passwd="${passwd}"
+ ;;
+ esac
+
+ printf "%s:x:%d:%d:%s:%s:%s\n" \
+ "${username}" "${uid}" "${_gid}" \
+ "${comment}" "${_home}" "${_shell}" \
+ >>"${PASSWD}"
+ printf "%s:%s:%d:0:99999:7:::\n" \
+ "${username}" "${_passwd}" "${nb_days}" \
+ >>"${SHADOW}"
+
+ # Add the user to its additional groups
+ if [ "${groups}" != "-" ]; then
+ for _group in ${groups//,/ }; do
+ add_user_to_group "${username}" "${_group}"
+ done
+ fi
+
+ # If the user has a home, chown it
+ # (Note: stdout goes to the fakeroot-script)
+ if [ "${home}" != "-" ]; then
+ mkdir -p "${TARGET_DIR}/${home}"
+ printf "chown -R %d:%d '%s'\n" "${uid}" "${_gid}" "${TARGET_DIR}/${home}"
+ fi
+}
+
+#----------------------------------------------------------------------------
+main() {
+ local username uid group gid passwd home shell groups comment
+
+ # Some sanity checks
+ if [ ${MIN_UID} -le 0 ]; then
+ fail "MIN_UID must be >0 (currently %d)\n" ${MIN_UID}
+ fi
+ if [ ${MIN_GID} -le 0 ]; then
+ fail "MIN_GID must be >0 (currently %d)\n" ${MIN_GID}
+ fi
+
+ # First, create all the main groups
+ while read username uid group gid passwd home shell groups comment; do
+ [ -n "${username}" ] || continue # Package with no user
+ add_one_group "${group}" "${gid}"
+ done <"${USERS_TABLE}"
+
+ # Then, create all the additional groups
+ # If any additional group is already a main group, we should use
+ # the gid of that main group; otherwise, we can use any gid
+ while read username uid group gid passwd home shell groups comment; do
+ [ -n "${username}" ] || continue # Package with no user
+ if [ "${groups}" != "-" ]; then
+ for g in ${groups//,/ }; do
+ add_one_group "${g}" -1
+ done
+ fi
+ done <"${USERS_TABLE}"
+
+ # Finally, add users
+ while read username uid group gid passwd home shell groups comment; do
+ [ -n "${username}" ] || continue # Package with no user
+ add_one_user "${username}" "${uid}" "${group}" "${gid}" "${passwd}" \
+ "${home}" "${shell}" "${groups}" "${comment}"
+ done <"${USERS_TABLE}"
+}
+
+#----------------------------------------------------------------------------
+main "${@}"
--
1.7.2.5
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