| Message ID | 0b0fa3ae335483e6402e2c15465cacdb2d51b0d7.1357070939.git.yann.morin.1998@free.fr |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi Yann, all, 2013/1/1 Yann E. MORIN <yann.morin.1998@free.fr>: > 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> > --- [snip] > @@ -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 You could add this in a new file... Why should makedev-syntax.txt contain syntax details for makedev and mkusers? > @@ -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. s/psecific/specific/ > + > +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. s/buildroot/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. ditto > +- +password+ is the crypt(3)-encrypted password. If prefixed with +=+, > + then it is interpreted as clear-text, and will be cypt-encoded. If s/cypt-encoded/crypt-encoded/ > + prefixed with +!+, then login is disabled. If set to +*+, then login > + is not allowed. Multiple prefix is allowed/supported; it could be explicitly mentioned. Is the prefix order important? So, the clear-text password itself should not starts with any prefix character? > +- +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 ditto > +- main +group+ is: +bar+ > +- main group +gid+ is computed by buildroot ditto > +- 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+ [snip] > --- /dev/null > +++ b/support/scripts/mkusers > @@ -0,0 +1,348 @@ > +#!/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" > +# /etc/gsahdow 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 s/hav/have/ Regards,
Smartin, All, On Tuesday 01 January 2013 Samuel Martin wrote: > 2013/1/1 Yann E. MORIN <yann.morin.1998@free.fr>: > > 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. [--SNIP--] > > 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 > You could add this in a new file... > Why should makedev-syntax.txt contain syntax details for makedev and mkusers? Right, I'll do. > > +- +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. > Multiple prefix is allowed/supported; it could be explicitly mentioned. > Is the prefix order important? > > So, the clear-text password itself should not starts with any prefix character? Oh! You raise a valid point here. In fact, I coded '=!' as being the same as '!=' , which it clearly is not. So, valid combinations are: * no password, login not allowed XXXX crypt-encoded password !XXXX crypt-encoded password, login disabled =1234 clear-text password !=1234 clear-text password, login disabled Thank you! Regards, Yann E. MORIN.
"Yann E. MORIN" <yann.morin.1998@free.fr> writes: >+* +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 "if it installs a program you want to run as a specific user" that is, s/daemon/program/ and s/with/as/ >+- +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. I think this is saying it creates groups as well as users. If so, the documentation should say so. Also, how do you specifiy that you do not want a group created - such as when you want a new user in an existing system group. I would assume something like foo -1 daemon -1 ... to create user "foo" in the system "daemon" group, but the documentation implies a new GID will be allocated. >+- +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. What is the status of the support of other encryption algorithms? e.g. $6$salt$enc for SHA-512 encrypted passwords? This will depend on settings in BuildRoot itself, but it would be worth making a reference here since it is relevant to a user providing encrypted user passwords. >+set -e .... >+USERS_TABLE="${1}" >+TARGET_DIR="${2}" >+shift 2 This will fail under 'set -e' if there are less than two parameters, but fail without any useful diagnostics. An error/usage message here would be useful. >+#---------------------------------------------------------------------------- >+error() { >+ local fmt="${1}" >+ shift >+ >+ printf "%s: " "${myname}" >&2 >+ printf "${fmt}" "${@}" >&2 I think you should put a \n in the format string here. Every call to this function (via fail) includes a \n, so it seems redundant require each caller to put a \n on the string. In fact, the last call to fail does not have a \n in the string which it should, so this will also fix what would probably become a common error. >+} >+fail() { >+ error "$@" >+ exit 1 >+} >+ >+#---------------------------------------------------------------------------- >+get_uid() { >+ local username="${1}" >+ >+ grep -r -E "${username}:" "${PASSWD}" |cut -d: -f3 Why grep -r? A recursive grep with a filename (non-directory) as an argument does not do anything different without -r. Ditto for get_ugid and get_gid. Why grep -E? You are not using any features of extended regular expressions. An argument could be made that you should be using grep -F. You should also anchor ${username} to the start of the line or you may get false matches: grep "^${username}:" "${PASSWD}" ditto get_ugid and get_gid. >+} >+ >+#---------------------------------------------------------------------------- >+get_ugid() { >+ local username="${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}" Is awk available in the host toolchain? If so, this would be much clearer with awk: awk -F: '$3 == '"${uid}"' { print $1 }' "${PASSWD}" ditto get_group >+} >+ >+#---------------------------------------------------------------------------- >+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 [ ${gid} -ge 0 ]; then Elsewhere in this script you check uid/gid against -1, not >= 0. This should be changed to "${gid} -eq -1" to be consistent with that and the documentation. >+ case "${home}" in >+ -) _home="/";; >+ /) fail "home can not be explicitly '/'\n";; >+ /*) _home="${home}";; >+ *) fail "home must be an absolute path";; This is where you missed the \n in the error message. There is also another spelling mistake somewhere :-) I noticed three when I first skimmed this patch; two have already been pointed out; and I did not see the third when I went through to comment.
"Yann E. MORIN" <yann.morin.1998@free.fr> writes: >+The syntax for adding a user is a space-separated list of fields, one >+user per-line; the fields are: per line - no hyphen here. >+* no field may contain a column (+:+). Found it - this is the third spelling mistake I referred to earlier. s/column/colon/
Cam, All, On Wednesday 02 January 2013 Cam Hutchison wrote: > "Yann E. MORIN" <yann.morin.1998@free.fr> writes: > > >+The syntax for adding a user is a space-separated list of fields, one > >+user per-line; the fields are: > > per line - no hyphen here. > > >+* no field may contain a column (+:+). > > Found it - this is the third spelling mistake I referred to earlier. > s/column/colon/ Thank you! Regards, Yann E. MORIN.
Cam, All, On Wednesday 02 January 2013 Cam Hutchison wrote: > "Yann E. MORIN" <yann.morin.1998@free.fr> writes: > > >+* +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 > > "if it installs a program you want to run as a specific user" > > that is, s/daemon/program/ and s/with/as/ Well, I would like to emphasise that this is primarily for running programs as daemons (ie. started by startup scripts). It does not really make sense to run program as a specific user when logged in, especially for embedded systems, where logging in a seldom done. What about: ... if it installs a daemon program you want to run as ... > >+- +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. > > I think this is saying it creates groups as well as users. If so, the > documentation should say so. OK. > Also, how do you specifiy that you do not want a group created - such > as when you want a new user in an existing system group. I would assume > something like > > foo -1 daemon -1 ... > > to create user "foo" in the system "daemon" group, but the documentation > implies a new GID will be allocated. Ah, yes. If the group already exists (because it is in the skeleton, or because a previous user added it), then the GID for that group is used, no new GID is created, of course. I'll add this to the doc. Good catch! > >+- +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. > > What is the status of the support of other encryption algorithms? e.g. > $6$salt$enc for SHA-512 encrypted passwords? This will depend on settings > in BuildRoot itself, but it would be worth making a reference here > since it is relevant to a user providing encrypted user passwords. First, this is not meant for buildroot users, but for buildroot developpers. This makes a huge difference, but shall be documented nonetheless, of course. If the developper enters an already-encoded des/md5/sha256/sha512 pasword (ie. a password that does not start with '=') then the content is used as-is. The current password encoding is md5 ($1$salt$...). Once my other patch to add selection of an alternative encoding, I'll use that here, too: http://lists.busybox.net/pipermail/buildroot/2012-December/064411.html > >+set -e > .... > >+USERS_TABLE="${1}" > >+TARGET_DIR="${2}" > >+shift 2 > > This will fail under 'set -e' if there are less than two parameters, but fail > without any useful diagnostics. An error/usage message here would be useful. OK. > >+#---------------------------------------------------------------------------- > >+error() { > >+ local fmt="${1}" > >+ shift > >+ > >+ printf "%s: " "${myname}" >&2 > >+ printf "${fmt}" "${@}" >&2 > > I think you should put a \n in the format string here. Every call to this > function (via fail) includes a \n, so it seems redundant require each caller > to put a \n on the string. In fact, the last call to fail does not have > a \n in the string which it should, so this will also fix what would > probably become a common error. I prefer to keep the \n is every calls. The missing one is an bug. > >+} > >+fail() { > >+ error "$@" > >+ exit 1 > >+} > >+ > >+#---------------------------------------------------------------------------- > >+get_uid() { > >+ local username="${1}" > >+ > >+ grep -r -E "${username}:" "${PASSWD}" |cut -d: -f3 > > Why grep -r? Indeed. > Why grep -E? You are not using any features of extended regular expressions. Because I *always* use 'grep -E', and I /forgot/ what is a standard regexp. But I can remove, yes. > An argument could be made that you should be using grep -F. I don't know (ie. I don't usualy use) this switch, so I am not confident in using it here. If plain 'grep' does the job, lets just use that. > You should also anchor ${username} Yes, indeed. > >+get_username() { > >+ local uid="${1}" > >+ > >+ sed -r -e '/^([^:]+):[^:]+:'"${uid}"':.*/!d; s//\1/;' "${PASSWD}" > > Is awk available in the host toolchain? Nopt systematically. There's host-gawk that package can depend on. If we were to use awk instead of sed, then host-gawk would always be built as soon as a rootfs image (fs/tarball/...) is generated. So, I prefer to keep using sed for now, unless Peter agrees we can build always build host-gawk. > >+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 [ ${gid} -ge 0 ]; then > > Elsewhere in this script you check uid/gid against -1, not >= 0. This > should be changed to "${gid} -eq -1" to be consistent with that and the > documentation. OK. Should also check for invalid (ie. -lt -1). > >+ case "${home}" in > >+ -) _home="/";; > >+ /) fail "home can not be explicitly '/'\n";; > >+ /*) _home="${home}";; > >+ *) fail "home must be an absolute path";; > > This is where you missed the \n in the error message. OK. > There is also another spelling mistake somewhere :-) I noticed three when > I first skimmed this patch; two have already been pointed out; and I did > not see the third when I went through to comment. Fixed! ;-) Thank you! Regards, Yann E. MORIN.
"Yann E. MORIN" <yann.morin.1998@free.fr> writes: >Cam, All, >On Wednesday 02 January 2013 Cam Hutchison wrote: >> "Yann E. MORIN" <yann.morin.1998@free.fr> writes: >> >> >+* +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 >> >> "if it installs a program you want to run as a specific user" >> >> that is, s/daemon/program/ and s/with/as/ >Well, I would like to emphasise that this is primarily for running >programs as daemons (ie. started by startup scripts). It does not >really make sense to run program as a specific user when logged in, >especially for embedded systems, where logging in a seldom done. >What about: >.... if it installs a daemon program you want to run as ... I was considering a case of a periodic cron job running as a non-root user - that is not a daemon, and is not related to logged-in users. Since there are no actual constraints that require that the user added be used only by a daemon, I figured the documentation should not introduce that constraint. But documenting intentions is fine and I have no strong feeling either way. >> >+#---------------------------------------------------------------------------- >> >+get_uid() { >> >+ local username="${1}" >> >+ >> >+ grep -r -E "${username}:" "${PASSWD}" |cut -d: -f3 >> >> An argument could be made that you should be using grep -F. >I don't know (ie. I don't usualy use) this switch, so I am not confident in >using it here. If plain 'grep' does the job, lets just use that. The problem with plain grep is that if the username contains a regular expression metachar, then grep will not work as expected in some cases. The most likely one is a period - a username of foo.bar will match an existing user of fooxbar and will not allow the creation of the user foo.bar. More strictly, it is a matter of handling user input correctly. The user was not expecting a username to be a regular expression, so it should not be treated as such ... >> You should also anchor ${username} >Yes, indeed. .... but a start-of-line anchor will not work with grep -F :-( Another +1 for awk here - processing record-oriented files is what awk is good at, but I can understand not wanting to introduce that dependency.
Dear Cam Hutchison, On Thu, 03 Jan 2013 02:35:16 -0000, Cam Hutchison wrote: > Another +1 for awk here - processing record-oriented files is what > awk is good at, but I can understand not wanting to introduce that > dependency. We already depend on awk: http://git.buildroot.net/buildroot/tree/support/dependencies/dependencies.sh#n133 Best regards, Thomas
Thomas, All, On Thursday 03 January 2013 Thomas Petazzoni wrote: > On Thu, 03 Jan 2013 02:35:16 -0000, Cam Hutchison wrote: > > Another +1 for awk here - processing record-oriented files is what > > awk is good at, but I can understand not wanting to introduce that > > dependency. > > We already depend on awk: > http://git.buildroot.net/buildroot/tree/support/dependencies/dependencies.sh#n133 OK, I'll update the script, then. Thanks! Regards, Yann E. MORIN.
Samuel, All, On Tuesday 01 January 2013 Yann E. MORIN wrote: > On Tuesday 01 January 2013 Samuel Martin wrote: > > 2013/1/1 Yann E. MORIN <yann.morin.1998@free.fr>: [--SNIP--] > > > +- +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. > > Multiple prefix is allowed/supported; it could be explicitly mentioned. > > Is the prefix order important? > > > > So, the clear-text password itself should not starts with any prefix character? [--SNIP--] > So, valid combinations are: > * no password, login not allowed > XXXX crypt-encoded password > !XXXX crypt-encoded password, login disabled > =1234 clear-text password > !=1234 clear-text password, login disabled And of course, '!' and '=' are not in the set of characters that crypt can emit for an encoded password, so it is legit to write: = empty password =!foo clear-text password starts with a '!' ==bar clear-text password starts with a '=' != empty password , login is disabled !=!foo clear-text password starts with a '!', login is disabled !==bar clear-text password starts with a '=', login is disabled Regards, Yann E. MORIN.
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) - -@rm -f $(FAKEROOT_SCRIPT) $(FULL_DEVICE_TABLE) + -@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)$$(sep) ifeq ($$($(2)_SITE_METHOD),svn) DL_TOOLS_DEPENDENCIES += svn diff --git a/support/scripts/mkusers b/support/scripts/mkusers new file mode 100755 index 0000000..9d89ff9 --- /dev/null +++ b/support/scripts/mkusers @@ -0,0 +1,348 @@ +#!/bin/bash +set -e +myname="${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="${TARGET_DIR}/etc/group" +# /etc/gsahdow is not part of the standard skeleton, so not everybody +# will have it, but some may hav it, and its content must be in sync +# with /etc/group, so any use of gshadow must be conditional. +GSHADOW="${TARGET_DIR}/etc/gshadow" + +#---------------------------------------------------------------------------- +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}" "${GSHADOW}"; do + [ -f "${_f}" ] || continue + sed -r -i -e '/^'"${group}"':.*/d;' "${_f}" + done + + printf "%s:x:%d:\n" "${group}" "${gid}" >>"${GROUP}" + if [ -f "${GSHADOW}" ]; then + 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/:,/:/' \ + "${_f}" + done +} + +#---------------------------------------------------------------------------- +# Add a user; if it does already exist, remove it first +add_one_user() { + local username="${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 "${@}"
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 | 348 +++++++++++++++++++++++++++++++ 5 files changed, 432 insertions(+), 3 deletions(-) create mode 100755 support/scripts/mkusers