Query: getpeereid
OS: mojave
Section: 3
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
GETPEEREID(3) BSD Library Functions Manual GETPEEREID(3)NAMEgetpeereid -- get the effective credentials of a UNIX-domain peerLIBRARYStandard C Library (libc, -lc)SYNOPSIS#include <sys/types.h> #include <unistd.h> int getpeereid(int s, uid_t *euid, gid_t *egid);DESCRIPTIONThe getpeereid() function returns the effective user and group IDs of the peer connected to a UNIX-domain socket. The argument s must be a UNIX-domain socket (unix(4)) of type SOCK_STREAM on which either connect(2) or listen(2) have been called. The effective used ID is placed in euid, and the effective group ID in egid. The credentials returned to the listen(2) caller are those of its peer at the time it called connect(2); the credentials returned to the connect(2) caller are those of its peer at the time it called listen(2). This mechanism is reliable; there is no way for either side to influence the credentials returned to its peer except by calling the appropriate system call (i.e., either connect(2) or listen(2)) under different effective credentials. One common use of this routine is for a UNIX-domain server to verify the credentials of its client. Likewise, the client can verify the cre- dentials of the server.IMPLEMENTATION NOTESOn FreeBSD, getpeereid() is implemented in terms of the LOCAL_PEERCRED unix(4) socket option.RETURN VALUESThe getpeereid() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi- cate the error.ERRORSThe getpeereid() function fails if: [EBADF] The argument s is not a valid descriptor. [ENOTSOCK] The argument s is a file, not a socket. [ENOTCONN] The argument s does not refer to a socket on which connect(2) or listen(2) have been called. [EINVAL] The argument s does not refer to a socket of type SOCK_STREAM, or the kernel returned invalid data.SEE ALSOconnect(2), getpeername(2), getsockname(2), getsockopt(2), listen(2), unix(4)HISTORYThe getpeereid() function appeared in FreeBSD 4.6.BSDJuly 15, 2001 BSD