man pages section 3: Extended Library Functions

match_execattr(3SECDB)

Name

getexecattr, free_execattr, setexecattr, endexecattr, getexecuser, getexecprof, match_execattr– get execution profile entry

Synopsis

cc [ flag... ] file... –lsecdb  –lsocket  –lnsl  [ library... ]
#include <exec_attr.h>
#include <secdb.h>

execattr_t *getexecattr(void);

void free_execattr(execattr_t *ep);

void setexecattr(void);

void endexecattr(void);

execattr_t *getexecuser(const char *username, const char *type,
     const char *id, int search_flag);

execattr_t *getexecprof(const char *profname, const char *type,
     const char *id, int search_flag);

execattr_t *match_execattr(execattr_t *ep, char *profname,
     char *type, char *id);

Description

The getexecattr() function returns a single exec_attr(4) entry. Entries can come from any of the sources specified in the nsswitch.conf(4) file.

Successive calls to getexecattr() return either successive exec_attr entries or NULL. Because getexecattr() always returns a single entry, the next pointer in the execattr_t data structure points to NULL.

The internal representation of an exec_attr entry is an execattr_t structure defined in <exec_attr.h> with the following members:

char              *name;   /* name of the profile */
char              *type;   /* type of profile */
char              *policy; /* policy under which the attributes are */
                           /* relevant*/
char              *res1;   /* reserved for future use */
char              *res2;   /* reserved for future use */
char              *id;     /* unique identifier */
kva_t             *attr;   /* attributes */
struct execattr_s *next;   /* optional pointer to next profile */

The free_execattr() function releases memory. It follows the next pointers in the execattr_t structure so that the entire linked list is released.

The setexecattr() function “rewinds” to the beginning of the enumeration of exec_attr entries. Calls to getexecuser() can leave the enumeration in an indeterminate state. Therefore, setexecattr() should be called before the first call to getexecattr().

The endexecattr() function can be called to indicate that exec_attr processing is complete; the library can then close any open exec_attr file, deallocate any internal storage, and so forth.

The getexecuser() function returns a linked list of entries that match the type and id arguments and have a profile that has been assigned to the user specified by username, as described in passwd(4). Profiles for the user are obtained from the list of default profiles in /etc/security/policy.conf (see policy.conf(4)) and the user_attr(4) database. Only entries in the name service scope for which the corresponding profile entry is found in the prof_attr(4) database are returned.

The getexecprof() function returns a linked list of entries that match the type and id arguments and have the profile specified by the profname argument. Only entries in the name service scope for which the corresponding profile entry is found in the prof_attr database are returned.

Using getexecuser() and getexecprof(), programmers can search for any type argument, such as the manifest constant KV_COMMAND. The arguments are logically AND-ed together so that only entries exactly matching all of the arguments are returned. Wildcard matching applies if there is no exact match for an ID. Any argument can be assigned the NULL value to indicate that it is not used as part of the matching criteria. The search_flag controls whether the function returns the first match (GET_ONE), setting the next pointer to NULL or all matching entries (GET_ALL), using the next pointer to create a linked list of all entries that meet the search criteria. See EXAMPLES.

Once a list of entries is returned by getexecuser() or getexecprof(), the convenience function match_execattr() can be used to identify an individual entry. It returns a pointer to the individual element with the same profile name ( profname), type name ( type), and id. Function parameters set to NULL are not used as part of the matching criteria. In the event that multiple entries meet the matching criteria, only a pointer to the first entry is returned. The kva_match(3SECDB) function can be used to look up a key in a key-value array.

Return Values

Those functions returning data only return data related to the active policy. The getexecattr() function returns a pointer to a execattr_t if it successfully enumerates an entry; otherwise it returns NULL, indicating the end of the enumeration.

Usage

The getexecattr(), getexecuser(), and getexecprof() functions all allocate memory for the pointers they return. This memory should be deallocated with the free_execattr() call. The match_execattr()( function does not allocate any memory. Therefore, pointers returned by this function should not be deallocated.

Individual attributes may be referenced in the attr structure by calling the kva_match(3SECDB) function.

Examples

Example 1 Find all profiles that have the `ping` command.

if ((execprof=getexecprof(NULL, KV_COMMAND, "/usr/sbin/ping", 
    GET_ONE)) == NULL) { 
        /* do error */
}

Example 2 Find the entry for the `ping` command in the Network Administration Profile.

if ((execprof=getexecprof("Network Administration", KV_COMMAND, 
    "/usr/sbin/ping", GET_ALL))==NULL) {
        /* do error */
}

Example 3 Tell everything that can be done in the Filesystem Security profile.

if ((execprof=getexecprof("Filesystem Security", KV_NULL, NULL, 
    GET_ALL))==NULL)) { 
        /* do error */
}

Example 4 Tell if the `tar` utility is in a profile assigned to user wetmore. If there is no exact profile entry, the wildcard (*), if defined, is returned.

The following tells if the tar utility is in a profile assigned to user wetmore. If there is no exact profile entry, the wildcard (*), if defined, is returned.

if ((execprof=getexecuser("wetmore", KV_COMMAND, "/usr/bin/tar", 
    GET_ONE))==NULL) {
        /* do error */
}

Files

/etc/nsswitch.conf: configuration file lookup information for the name server switch
/etc/user_attr: extended user attributes
/etc/security/exec_attr: execution profiles
/etc/security/policy.conf: policy definitions

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
MT-Level	MT-Safe