Проект OpenNet: MAN ppriv (1) Команды и прикладные программы пользовательского уровня (FreeBSD и Linux)

Интерактивная система просмотра системных руководств (man-ов)

ppriv (1)

>> ppriv (1) ( Solaris man: Команды и прикладные программы пользовательского уровня )

NAME

ppriv - inspect or modify process privilege sets and attributes

SYNOPSIS

/usr/bin/ppriv -e [-D | -N] [-M] [-s spec] command [arg]...

/usr/bin/ppriv [-v] [-S] [-D | -N] [-s spec] 
    [pid | core]...

/usr/bin/ppriv -l [-v] [privilege-specification]...

DESCRIPTION

The first invocation of the ppriv command runs the command specified with the privilege sets and flags modified according to the arguments on the command line.

The second invocation examines or changes the privilege state of running process and core files.

The third invocation lists the privileges defined and information about specified privileges or privileges set specifications.

OPTIONS

The following options are supported:

-D

: Turns on privilege debugging for the processes or command supplied.

-e

: Interprets the remainder of the arguments as a command line and runs the command line with specified privilege attributes and sets.

-l

: Lists all currently defined privileges on stdout.

-M

: When a system is configured with Trusted Extensions, this option turns on the NET_MAC_AWARE and NET_MAC_AWARE_INHERIT process attributes.
A process with these attributes and the net_mac_aware privilege can communicate with lower-level remote peers.

-N

: Turns off privilege debugging for the processes or command supplied.

-s spec

Modifies a process's privilege sets according to spec, a specification with the format [AEILP][+-=]privsetspec, containing no spaces, where:

AEILP

: Indicates one or more letters indicating which privilege sets to change. These are case insensitive, for example, either a or A indicates all privilege sets.

+-=

: Indicates a modifier to respectively add (+), remove (-), or assign (=) the listed privileges to the specified set(s) in privsetspec.

privsetspec

: Indicates a comma-separated privilege set specification (priv1,priv2, and so on), as described in priv_str_to_set(3C).

Modifying the same set with multiple -s options is possible as long as there is either precisely one assignment to an individual set or any number of additions and removals. That is, assignment and addition or removal for one set are mutually exclusive.

-S

: Short. Reports the shortest possible output strings for sets. The default is portable output. See priv_str_to_set(3C).

-v

: Verbose. Reports privilege sets using privilege names.

USAGE

The ppriv utility examines processes and core files and prints or changes their privilege sets.

ppriv can run commands with privilege debugging on or off or with fewer privileges than the invoking process.

When executing a sub process, the only sets that can be modified are L and I. Privileges can only be removed from L and I as ppriv starts with P=E=I.

ppriv can also be used to remove privileges from processes or to convey privileges to other processes. In order to control a process, the effective set of the ppriv utility must be a super set of the controlled process's E, I, and P. The utility's limit set must be a super set of the target's limit set. If the target's process uids do not match, the {PRIV_PROC_OWNER} privilege must be asserted in the utility's effective set. If the controlled processes have any uid with the value 0, more restrictions might exist. See privileges(5).

EXAMPLES

Example 1 Obtaining the Process Privileges of the Current Shell

The following example obtains the process privileges of the current shell:

example$ ppriv $$
387:   -sh
flags = <none>
        E: basic
        I: basic
        P: basic
        L: all

Example 2 Removing a Privilege From Your Shell's Inheritable and Effective Set

The following example removes a privilege from your shell's inheritable and effective set.

example$ ppriv -s EI-proc_session $$

The subprocess can still inspect the parent shell but it can no longer influence the parent because the parent has more privileges in its Permitted set than the ppriv child process:

example$ truss -p $$
truss: permission denied: 387

example$ ppriv $$
387:   -sh
flags = <none>
        E: basic,!proc_session
        I: basic,!proc_session
        P: basic
        L: all

Example 3 Running a Process with Privilege Debugging

The following example runs a process with privilege debugging:

example$ ppriv -e -D cat /etc/shadow
cat[418]: missing privilege "file_dac_read" (euid = 21782),
                   needed at ufs_access+0x3c
cat: cannot open /etc/shadow

The privilege debugging error messages are sent to the controlling terminal of the current process. The needed at address specification is an artifact of the kernel implementation and it can be changed at any time after a software update.

The system call number can be mapped to a system call using /etc/name_to_sysnum.

Example 4 Listing the Privileges Available in the Current Zone

The following example lists the privileges available in the current zone (see zones(5)). When run in the global zone, all defined privileges are listed.

example$ ppriv -l zone

Example 5 Examining a Privilege Aware Process

The following example examines a privilege aware process:

example$ ppriv -S `pgrep rpcbind`


928:    /usr/sbin/rpcbind
flags = PRIV_AWARE
       E: net_privaddr,proc_fork,sys_nfs
       I: none
       P: net_privaddr,proc_fork,sys_nfs
       L: none

See setpflags(2) for explanations of the flags.