1 /*-------------------------------------------------------------------------
2  *
3  * getpeereid.c
4  *		get peer userid for UNIX-domain socket connection
5  *
6  * Portions Copyright (c) 1996-2018, 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  */
34 int
getpeereid(int sock,uid_t * uid,gid_t * gid)35 getpeereid(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