getdvagent(3)

NAME

getdvagent(), getdvagnam(), setdvagent(), enddvagent(), putdvagnam(), copydvagent() — manipulate device assignment database entry for a trusted system

SYNOPSIS

#include <sys/types.h>
#include <hpsecurity.h>
#include <prot.h>

struct dev_asg *getdvagent();

struct dev_asg *getdvagnam(const char *name);

void setdvagent();

void enddvagent();

int putdvagnam(const char *name, struct dev_asg *dv);

struct dev_asg *copydvagent(struct dev_asg *dv);

DESCRIPTION

getdvagent, getdvagnam, and copydvagent each return a pointer to an object with the following structure containing the broken-out fields of an entry in the Device Assignment database. Each database entry is returned as a dev_asg structure, declared in the <prot.h> header file:

struct dev_field {
     char      *fd_name;        /* external name */
     char      **fd_devs;       /* device list */
     mask_t    fd_type[1];      /* tape, printer, terminal */
     char      **fd_users;      /* authorized user list */
};

/* Device Assignment Database entry */

#define AUTH_DEV_TYPE           "device type"
#define AUTH_DEV_PRINTER        0
#define AUTH_DEV_TERMINAL       1
#define AUTH_DEV_TAPE           2
#define AUTH_DEV_REMOTE         3
#define AUTH_MAX_DEV_TYPE       3
#define AUTH_DEV_TYPE_SIZE      (WORD_OF_BIT (AUTH_MAX_DEV_TYPE) + 1)

/* this structure tells which of the corresponding fields
 * in dev_field are valid (filled).
 */
struct dev_flag {
     unsigned short
          fg_name  : 1,
          fg_devs  : 1,
          fg_type  : 1,
          fg_users : 1,
     ;
};

struct dev_asg {
     struct dev_field ufld;
     struct dev_flag  uflg;
     struct dev_field sfld;
     struct dev_flag  sflg;
};

The Device Assignment database stores device characteristics that are related to user authorizations and synonyms. On systems supporting network connections, the Device Assignment database stores information about hosts initiating connections.

Each entry contains a name, which is a cross reference to the terminal control database, and a list of devices, each of which is a pathname corresponding to that device. This list allows the device assignment software of the trusted system to invalidate all references to a device when re-assigning it. The list is a table of character string pointers, whose last entry is a NULL pointer.

fd_users is a pointer to a null-terminated table of character string pointers referring to user allowed access.

For trusted system versions supporting network connections, the device name can be a 12 character host name, where the first 8 characters are the ASCII hex address of the device, and the last 4 characters are ASCII zeroes. For example, a host with Internet address 129.75.0.3 has device name 814b00030000. The trailing four zeroes are for compatibility with ports on terminal concentrators. The SAM API's supports conversion of host name to device name. Thus, sensitivity level ranges and user authorization lists can be enforced on hosts as well as on directly connected terminals.

When getdvagent is first called, it returns a pointer to the first device assignment entry. Thereafter, it returns a pointer to the next entry, so successive calls can be used to search the database. getdvagnam searches from the beginning of the database until an entry with a device name matching name is found, and returns a pointer to that entry. If an end of file or an error is encountered on reading, these functions return a NULL pointer. copydvagent copies a device assignment structure and the fields to which it refers to a newly-allocated data area. Since getdvagent, getdvagnam, and putdvagent re-use a static structure when accessing the database, the values of any entry must be saved if these routines are used again. The dev_asg structure returned by copydvagent can be freed using free (see malloc(3C)).

A call to setdvagent has the effect of setting the device assignment database back to the first entry to allow repeated searches of the database. enddvagent frees all memory and closes all files used to support these routines.

putdvagnam rewrites or adds an entry to the database. If there is an entry whose fd_name field matches the name argument, that entry is replaced with the contents of the dv structure. Otherwise, that entry is added to the database.

Notes

Programs using this routine must be compiled with -lsec.

APPLICATION USAGE

In a multithreaded application, these routines are safe to be called only from one dedicated thread. These routines are not POSIX.1c async-cancel safe nor async-signal safe.

RETURN VALUE

getdvagent and getdvagnam return a pointer to a static structure on success, or a NULL pointer on failure. This static structure is overwritten by getdvagent, getdvagnam, and putdvagnam.

putdvagnam returns 1 on success, or 0 on failure.

copydvagent returns a pointer to the newly-allocated structure on success, or a NULL pointer if there was a memory allocation error.

WARNINGS

The structure returned by this routine contains pointers to character strings and lists rather than being self-contained. copydvagent must be used instead of structure assignments to save a returned structure.

The value returned by getdvagent and getdvagnam refers to a structure that is overwritten by calls to these routines. To retrieve an entry, modify it, and replace it in the database, copy the entry using copydvagent and supply the modified buffer to putdvagent.

HP-UX 11i Version 3 is the last release to support trusted systems functionality.

FILES

/tcb/files/devassign: Device assignment database

getdvagent(3)

Technical documentation

» Table of Contents

» Index