1/*-------------------------------------------------------------------------
2 *
3 * getpeereid.c
4 * get peer userid for UNIX-domain socket connection
5 *
6 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7 *
8 *
9 * IDENTIFICATION
10 * src/port/getpeereid.c
11 *
12 *-------------------------------------------------------------------------
13 */
14
15#include "c.h"
16
17#include <sys/param.h>
18#include <sys/socket.h>
19#include <unistd.h>
20#ifdef HAVE_SYS_UN_H
21#include <sys/un.h>
22#endif
23#ifdef HAVE_UCRED_H
24#include <ucred.h>
25#endif
26#ifdef HAVE_SYS_UCRED_H
27#include <sys/ucred.h>
28#endif
29
30
31/*
32 * BSD-style getpeereid() for platforms that lack it.
33 */
34int
35getpeereid(int sock, uid_t *uid, gid_t *gid)
36{
37#if defined(SO_PEERCRED)
38 /* Linux: use getsockopt(SO_PEERCRED) */
39 struct ucred peercred;
40 ACCEPT_TYPE_ARG3 so_len = sizeof(peercred);
41
42 if (getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &peercred, &so_len) != 0 ||
43 so_len != sizeof(peercred))
44 return -1;
45 *uid = peercred.uid;
46 *gid = peercred.gid;
47 return 0;
48#elif defined(LOCAL_PEERCRED)
49 /* Debian with FreeBSD kernel: use getsockopt(LOCAL_PEERCRED) */
50 struct xucred peercred;
51 ACCEPT_TYPE_ARG3 so_len = sizeof(peercred);
52
53 if (getsockopt(sock, 0, LOCAL_PEERCRED, &peercred, &so_len) != 0 ||
54 so_len != sizeof(peercred) ||
55 peercred.cr_version != XUCRED_VERSION)
56 return -1;
57 *uid = peercred.cr_uid;
58 *gid = peercred.cr_gid;
59 return 0;
60#elif defined(HAVE_GETPEERUCRED)
61 /* Solaris: use getpeerucred() */
62 ucred_t *ucred;
63
64 ucred = NULL; /* must be initialized to NULL */
65 if (getpeerucred(sock, &ucred) == -1)
66 return -1;
67
68 *uid = ucred_geteuid(ucred);
69 *gid = ucred_getegid(ucred);
70 ucred_free(ucred);
71
72 if (*uid == (uid_t) (-1) || *gid == (gid_t) (-1))
73 return -1;
74 return 0;
75#else
76 /* No implementation available on this platform */
77 errno = ENOSYS;
78 return -1;
79#endif
80}
81