diff options
| -rw-r--r-- | docs/manual/adding-packages-generic.txt | 16 | ||||
| -rw-r--r-- | docs/manual/appendix.txt | 1 | ||||
| -rw-r--r-- | docs/manual/makeusers-syntax.txt | 87 | ||||
| -rw-r--r-- | fs/common.mk | 3 | ||||
| -rw-r--r-- | package/pkg-generic.mk | 1 | ||||
| -rwxr-xr-x | support/scripts/mkusers | 409 |
6 files changed, 515 insertions, 2 deletions
diff --git a/docs/manual/adding-packages-generic.txt b/docs/manual/adding-packages-generic.txt index a615ae2c9..aa94b8869 100644 --- a/docs/manual/adding-packages-generic.txt +++ b/docs/manual/adding-packages-generic.txt @@ -53,7 +53,11 @@ system is based on hand-written Makefiles or shell scripts. 36: /bin/foo f 4755 0 0 - - - - - 37: endef 38: -39: $(eval $(generic-package)) +39: define LIBFOO_USERS +40: foo -1 libfoo -1 * - - - LibFoo daemon +41: endef +42: +43: $(eval $(generic-package)) -------------------------------- The Makefile begins on line 7 to 11 with metadata information: the @@ -140,7 +144,10 @@ On line 31..33, we define a device-node file used by this package On line 35..37, we define the permissions to set to specific files installed by this package (+LIBFOO_PERMISSIONS+). -Finally, on line 39, we call the +generic-package+ function, which +On lines 39..41, we define a user that is used by this package (eg. +to run a daemon as non-root) (+LIBFOO_USERS+). + +Finally, on line 43, we call the +generic-package+ function, which generates, according to the variables defined previously, all the Makefile code necessary to make your package working. @@ -307,6 +314,11 @@ 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 program you want to run as a specific user (eg. as a daemon, or as a + cron-job). 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/appendix.txt b/docs/manual/appendix.txt index ef34169f8..c48c3b169 100644 --- a/docs/manual/appendix.txt +++ b/docs/manual/appendix.txt @@ -5,6 +5,7 @@ Appendix ======== include::makedev-syntax.txt[] +include::makeusers-syntax.txt[] [[package-list]] Available packages diff --git a/docs/manual/makeusers-syntax.txt b/docs/manual/makeusers-syntax.txt new file mode 100644 index 000000000..21996546c --- /dev/null +++ b/docs/manual/makeusers-syntax.txt @@ -0,0 +1,87 @@ +// -*- mode:doc -*- ; + +[[makeuser-syntax]] +Makeuser syntax documentation +----------------------------- + +The syntax to create users is inspired by the makedev syntax, above, but +is specific 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 can not be +root+, and 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 + in the range [1000...1999] +- +group+ is the desired name for the user's main group. It can not + be +root+. If the group does not exist, it will be created. +- +gid+ is the desired GID for the user's main group. It must be unique, + and not +0+. If set to +-1+, and the group does not already exist, then + a unique GID will be computed by Buildroot in the range [1000..1999] +- +password+ is the crypt(3)-encoded password. If prefixed with +!+, + then login is disabled. If prefixed with +=+, then it is interpreted + as clear-text, and will be crypt-encoded (using MD5). If prefixed with + +!=+, then the password will be crypt-encoded (using MD5) and login + will be 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. Missing groups will be created with an arbitrary + +gid+. +- +comment+ (aka https://en.wikipedia.org/wiki/Gecos_field[GECOS] + field) 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 colon (+:+). + +If +home+ is not +-+, then the home directory, and all files below, +will belong to the user and its main group. + +Examples: + +---- +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)-encoded, and 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+ + +---- +test 8000 wheel -1 = - /bin/sh - Test user +---- + +This will create this user: + +- +username+ (aka login name) is: +test+ +- +uid+ is : +8000+ +- main +group+ is: +wheel+ +- main group +gid+ is computed by Buildroot, and will use the value defined in the rootfs skeleton +- +password+ is empty (aka no password). +- +home+ is +/+ but will not belong to +test+ +- +shell+ is: +/bin/sh+ +- +test+ is not a member of any additional +groups+ +- +comment+ is: +Test user+ diff --git a/fs/common.mk b/fs/common.mk index c6f67d831..36da2dd64 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) \ $(BR2_ROOTFS_STATIC_DEVICE_TABLE)) +USERS_TABLE = $(BUILD_DIR)/_users_table.txt define ROOTFS_TARGET_INTERNAL @@ -55,6 +56,8 @@ 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 -- $$(FAKEROOT_SCRIPT) diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk index e6bc95599..b55b5f0b4 100644 --- a/package/pkg-generic.mk +++ b/package/pkg-generic.mk @@ -529,6 +529,7 @@ ifeq ($$($$($(2)_KCONFIG_VAR)),y) TARGETS += $(1) PACKAGES_PERMISSIONS_TABLE += $$($(2)_PERMISSIONS)$$(sep) PACKAGES_DEVICES_TABLE += $$($(2)_DEVICES)$$(sep) +PACKAGES_USERS += $$($(2)_USERS)$$(sep) ifeq ($$($(2)_SITE_METHOD),svn) DL_TOOLS_DEPENDENCIES += svn diff --git a/support/scripts/mkusers b/support/scripts/mkusers new file mode 100755 index 000000000..19aa085e1 --- /dev/null +++ b/support/scripts/mkusers @@ -0,0 +1,409 @@ +#!/bin/bash +set -e +myname="${0##*/}" + +#---------------------------------------------------------------------------- +# Configurable items +MIN_UID=1000 +MAX_UID=1999 +MIN_GID=1000 +MAX_GID=1999 +# No more is configurable below this point +#---------------------------------------------------------------------------- + +#---------------------------------------------------------------------------- +error() { + local fmt="${1}" + shift + + printf "%s: " "${myname}" >&2 + printf "${fmt}" "${@}" >&2 +} +fail() { + error "$@" + exit 1 +} + +#---------------------------------------------------------------------------- +if [ ${#} -ne 2 ]; then + fail "usage: %s USERS_TABLE TARGET_DIR\n" +fi +USERS_TABLE="${1}" +TARGET_DIR="${2}" +shift 2 +PASSWD="${TARGET_DIR}/etc/passwd" +SHADOW="${TARGET_DIR}/etc/shadow" +GROUP="${TARGET_DIR}/etc/group" +# /etc/gshadow is not part of the standard skeleton, so not everybody +# will have it, but some may hav it, and its content must be in sync +# with /etc/group, so any use of gshadow must be conditional. +GSHADOW="${TARGET_DIR}/etc/gshadow" + +# We can't simply source ${BUILDROOT_CONFIG} as it may contains constructs +# such as: +# BR2_DEFCONFIG="$(CONFIG_DIR)/defconfig" +# which when sourced from a shell script will eventually try to execute +# a command name 'CONFIG_DIR', which is plain wrong for virtually every +# systems out there. +# So, we have to scan that file instead. Sigh... :-( +PASSWD_METHOD="$( sed -r -e '/^BR2_TARGET_GENERIC_PASSWD_METHOD="(.*)"$/!d;' \ + -e 's//\1/;' \ + "${BUILDROOT_CONFIG}" \ + )" + +#---------------------------------------------------------------------------- +get_uid() { + local username="${1}" + + awk -F: -v username="${username}" \ + '$1 == username { printf( "%d\n", $3 ); }' "${PASSWD}" +} + +#---------------------------------------------------------------------------- +get_ugid() { + local username="${1}" + + awk -F:i -v username="${username}" \ + '$1 == username { printf( "%d\n", $4 ); }' "${PASSWD}" +} + +#---------------------------------------------------------------------------- +get_gid() { + local group="${1}" + + awk -F: -v group="${group}" \ + '$1 == group { printf( "%d\n", $3 ); }' "${GROUP}" +} + +#---------------------------------------------------------------------------- +get_username() { + local uid="${1}" + + awk -F: -v uid="${uid}" \ + '$3 == uid { printf( "%s\n", $1 ); }' "${PASSWD}" +} + +#---------------------------------------------------------------------------- +get_group() { + local gid="${1}" + + awk -F: -v gid="${gid}" \ + '$3 == gid { printf( "%s\n", $1 ); }' "${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 "${username}" )" + + if [ "${username}" = "root" ]; then + fail "invalid username '%s\n'" "${username}" + fi + + if [ ${gid} -lt -1 -o ${gid} -eq 0 ]; then + fail "invalid gid '%d'\n" ${gid} + elif [ ${gid} -ne -1 ]; then + # check the gid is not already used for another group + if [ -n "${_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} -lt -1 -o ${uid} -eq 0 ]; then + fail "invalid uid '%d'\n" ${uid} + elif [ ${uid} -ne -1 ]; then + # check the uid is not already used for another user + if [ -n "${_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 "${group}" )" + fi + + # Remove any previous instance of this group, and re-add the new one + sed -i -e '/^'"${group}"':.*/d;' "${GROUP}" + printf "%s:x:%d:\n" "${group}" "${gid}" >>"${GROUP}" + + # Ditto for /etc/gshadow if it exists + if [ -f "${GSHADOW}" ]; then + sed -i -e '/^'"${group}"':.*/d;' "${GSHADOW}" + printf "%s:*::\n" "${group}" >>"${GSHADOW}" + fi +} + +#---------------------------------------------------------------------------- +# Generate a unique UID for given username. If the username already exists, +# then simply report its current UID. Otherwise, generate the lowest UID +# that is: +# - not 0 +# - comprised in [MIN_UID..MAX_UID] +# - not already used by a user +generate_uid() { + local username="${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}" "${GSHADOW}"; do + [ -f "${_f}" ] || continue + sed -r -i -e 's/^('"${group}"':.*:)(([^:]+,)?)'"${username}"'(,[^:]+*)?$/\1\2\4/;' \ + -e 's/^('"${group}"':.*)$/\1,'"${username}"'/;' \ + -e 's/,+/,/' \ + -e 's/:,/:/' \ + "${_f}" + done +} + +#---------------------------------------------------------------------------- +# Encode a password +encode_password() { + local passwd="${1}" + + mkpasswd -m "${PASSWD_METHOD}" "${passwd}" +} + +#---------------------------------------------------------------------------- +# 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="${9}" + local _f _group _home _shell _gid _passwd + + # First, sanity-check the user + check_user_validity "${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 explicitly be '/'\n";; + /*) _home="${home}";; + *) fail "home must be an absolute path\n";; + esac + case "${passwd}" in + !=*) + _passwd='!'"$( encode_passwd "${passwd#!=}" )" + ;; + =*) + _passwd="$( encode_passwd "${passwd#=}" )" + ;; + *) + _passwd="${passwd}" + ;; + esac + + printf "%s:x:%d:%d:%s:%s:%s\n" \ + "${username}" "${uid}" "${_gid}" \ + "${comment}" "${_home}" "${_shell}" \ + >>"${PASSWD}" + printf "%s:%s:::::::\n" \ + "${username}" "${_passwd}" \ + >>"${SHADOW}" + + # Add the user to its additional groups + if [ "${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" ${MIN_GID} + fi + + # We first create groups whose gid is not -1, and then we create groups + # whose gid is -1 (automatic), so that, if a group is defined both with + # a specified gid and an automatic gid, we ensure the specified gid is + # used, rather than a different automatic gid is computed. + + # First, create all the main groups which gid is *not* automatic + while read username uid group gid passwd home shell groups comment; do + [ -n "${username}" ] || continue # Package with no user + [ ${gid} -ge 0 ] || continue # Automatic gid + add_one_group "${group}" "${gid}" + done <"${USERS_TABLE}" + + # Then, create all the main groups which gid *is* automatic + while read username uid group gid passwd home shell groups comment; do + [ -n "${username}" ] || continue # Package with no user + [ ${gid} -eq -1 ] || continue # Non-automatic gid + add_one_group "${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 <"${USERS_TABLE}" + + # When adding users, we do as for groups, in case two packages create + # the same user, one with an automatic uid, the other with a specified + # uid, to ensure the specified uid is used, rather than an incompatible + # uid be generated. + + # Now, add users whose uid is *not* automatic + while read username uid group gid passwd home shell groups comment; do + [ -n "${username}" ] || continue # Package with no user + [ ${uid} -ge 0 ] || continue # Automatic uid + add_one_user "${username}" "${uid}" "${group}" "${gid}" "${passwd}" \ + "${home}" "${shell}" "${groups}" "${comment}" + done <"${USERS_TABLE}" + + # Finally, add users whose uid *is* automatic + while read username uid group gid passwd home shell groups comment; do + [ -n "${username}" ] || continue # Package with no user + [ ${uid} -eq -1 ] || continue # Non-automatic uid + add_one_user "${username}" "${uid}" "${group}" "${gid}" "${passwd}" \ + "${home}" "${shell}" "${groups}" "${comment}" + done <"${USERS_TABLE}" +} + +#---------------------------------------------------------------------------- +main "${@}" |