man pages section 3: Basic Library Functions

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Updated: July 2014
 
 

ucred_get(3C)

Name

ucred_get, ucred_free, ucred_geteuid, ucred_getruid, ucred_getsuid, ucred_getegid, ucred_getrgid, ucred_getsgid, ucred_getgroups, ucred_getprivset, ucred_getpid, ucred_getprojid, ucred_getzoneid, ucred_getpflags, ucred_getlabel, ucred_size - user credential functions

Synopsis

#include <ucred.h>

ucred_t *ucred_get(pid_t pid);
void ucred_free(ucred_t *uc);
uid_t ucred_geteuid(const ucred_t *uc);
uid_t ucred_getruid(const ucred_t *uc);
uid_t ucred_getsuid(const ucred_t *uc);
gid_t ucred_getegid(const ucred_t *uc);
gid_t ucred_getrgid(const ucred_t *uc);
gid_t ucred_getsgid(const ucred_t *uc);
int ucred_getgroups(const ucred_t *uc, const gid_t **groups);
const priv_set_t *ucred_getprivset(const ucred_t *uc,
     priv_ptype_t set);
pid_t ucred_getpid(const ucred_t *uc);
projid_t ucred_getprojid(const ucred_t *uc);
zoneid_t ucred_getzoneid(const ucred_t *uc);
uint_t ucred_getpflags(const ucred_t *uc, uint_t flags);
m_label_t *ucred_getlabel(const ucred_t *uc);
size_t ucred_size(void);

Description

These functions return or act on a user credential, ucred_t. User credentials are returned by various functions and describe the credentials of a process. Information about the process can then be obtained by calling the access functions. Access functions can fail if the underlying mechanism did not return sufficient information.

The ucred_get() function returns the user credential of the specified pid or NULL if none can be obtained. A pid value of P_MYID returns information about the calling process. The return value is dynamically allocated and must be freed using ucred_free().

The ucred_geteuid(), ucred_getruid(), ucred_getsuid(), ucred_getegid(), ucred_getrgid(), and ucred_getsgid() functions return the effective UID, real UID, saved UID, effective GID, real GID, saved GID, respectively, or -1 if the user credential does not contain sufficient information.

The ucred_getgroups() function stores a pointer to the group list in the gid_t * pointed to by the second argument and returns the number of groups in the list. It returns -1 if the information is not available. The returned group list is valid until ucred_free() is called on the user credential given as argument.

The ucred_getpid() function returns the process ID of the process or -1 if the process ID is not available. The process ID returned in a user credential is only guaranteed to be correct in a very limited number of cases when returned by door_ucred(3C) and ucred_get(). In all other cases, the process in question might have handed of the file descriptor, the process might have exited or executed another program, or the process ID might have been reused by a completely unrelated process after the original program exited.

The ucred_getprojid() function returns the project ID of the process or -1 if the project ID is not available.

The ucred_getzoneid() function returns the zone ID of the process or −1 if the zone ID is not available.

The ucred_getprivset() function returns the specified privilege set specified as second argument, or NULL if either the requested information is not available or the privilege set name is invalid. The returned privilege set is valid until ucred_free() is called on the specified user credential.

The ucred_getpflags() function returns the value of the specified privilege flags from the ucred structure, or (uint_t)-1 if none was present.

The ucred_getlabel() function returns the value of the label, or NULL if the label is not available. The returned label is valid until ucred_free() is called on the specified user credential. This function is available only if the system is configured with Trusted Extensions.

The ucred_free() function frees the memory allocated for the specified user credential.

The ucred_size() function returns sizeof(ucred_t). This value is constant only until the next boot, at which time it could change. The ucred_size() function can be used to determine the size of the buffer needed to receive a credential option with SO_RECVUCRED. See socket.h(3HEAD).

Return Values

See DESCRIPTION.

Errors

The ucred_get() function will fail if:

EAGAIN

There is not enough memory available to allocate sufficient memory to hold a user credential. The application can try again later.

EACCES

The caller does not have sufficient privileges to examine the target process.

EMFILE
ENFILE

The calling process cannot open any more files.

ENOMEM

The physical limits of the system are exceeded by the memory allocation needed to hold a user credential.

ESRCH

The target process does not exist.

The ucred_getprivset() function will fail if:

EINVAL

The privilege set argument is invalid.

The ucred_getlabel() function will fail if:

EINVAL

The label is not present.

The ucred_geteuid(), ucred_getruid(), ucred_getsuid(), ucred_getegid(), ucred_getrgid(), ucred_getsgid(), ucred_getgroups(), ucred_getpflags(), ucred_getprivset(), ucred_getprojid(), ucred_getpid(), and ucred_getlabel() functions will fail if:

EINVAL

The requested user credential attribute is not available in the specified user credential.

Attributes

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

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
MT-Level
MT-Safe

See Also

getpflags(2), getppriv(2), door_ucred(3C), getpeerucred(3C), priv_set(3C), socket.h(3HEAD) , attributes(5), labels(5), privileges(5)