summaryrefslogtreecommitdiffstats
path: root/libraries/liblutil/getpeereid.c
blob: 423fc7e78be221aa2bd962297055aa4ee9516901 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/* getpeereid.c */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 2000-2022 The OpenLDAP Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1			/* Needed for glibc struct ucred */
#endif

#include "portable.h"

#ifndef HAVE_GETPEEREID

#include <sys/types.h>
#include <ac/unistd.h>

#include <ac/socket.h>
#include <ac/errno.h>

#ifdef HAVE_GETPEERUCRED
#include <ucred.h>
#endif

#ifdef LDAP_PF_LOCAL_SENDMSG
#include <lber.h>
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#include <sys/stat.h>
#endif

#ifdef HAVE_SYS_UCRED_H
#ifdef HAVE_GRP_H
#include <grp.h>	/* for NGROUPS on Tru64 5.1 */
#endif
#include <sys/ucred.h>
#endif

#include <stdlib.h>

int lutil_getpeereid( int s, uid_t *euid, gid_t *egid
#ifdef LDAP_PF_LOCAL_SENDMSG
	, struct berval *peerbv
#endif
	)
{
#ifdef LDAP_PF_LOCAL
#if defined( HAVE_GETPEERUCRED )
	ucred_t *uc = NULL;
	if( getpeerucred( s, &uc ) == 0 )  {
		*euid = ucred_geteuid( uc );
		*egid = ucred_getegid( uc );
		ucred_free( uc );
		return 0;
	}

#elif defined( SO_PEERCRED )
	struct ucred peercred;
	ber_socklen_t peercredlen = sizeof peercred;

	if(( getsockopt( s, SOL_SOCKET, SO_PEERCRED,
		(void *)&peercred, &peercredlen ) == 0 )
		&& ( peercredlen == sizeof peercred ))
	{
		*euid = peercred.uid;
		*egid = peercred.gid;
		return 0;
	}

#elif defined( LOCAL_PEERCRED )
	struct xucred peercred;
	ber_socklen_t peercredlen = sizeof peercred;

	if(( getsockopt( s, LOCAL_PEERCRED, 1,
		(void *)&peercred, &peercredlen ) == 0 )
		&& ( peercred.cr_version == XUCRED_VERSION ))
	{
		*euid = peercred.cr_uid;
		*egid = peercred.cr_gid;
		return 0;
	}
#elif defined( LDAP_PF_LOCAL_SENDMSG ) && defined( MSG_WAITALL )
	int err, fd;
	struct iovec iov;
	struct msghdr msg = {0};
# ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
# ifndef CMSG_SPACE
# define CMSG_SPACE(len)	(_CMSG_ALIGN(sizeof(struct cmsghdr)) + _CMSG_ALIGN(len))
# endif
# ifndef CMSG_LEN
# define CMSG_LEN(len)		(_CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
# endif
	struct {
		struct cmsghdr cm;
		int fd;
	} control_st;
	struct cmsghdr *cmsg;
# endif /* HAVE_STRUCT_MSGHDR_MSG_CONTROL */
	struct stat st;
	struct sockaddr_un lname, rname;
	ber_socklen_t llen, rlen;

	rlen = sizeof(rname);
	llen = sizeof(lname);
	memset( &lname, 0, sizeof( lname ));
	getsockname(s, (struct sockaddr *)&lname, &llen);

	iov.iov_base = peerbv->bv_val;
	iov.iov_len = peerbv->bv_len;
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	peerbv->bv_len = 0;

# ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
	msg.msg_control = &control_st;
	msg.msg_controllen = sizeof( struct cmsghdr ) + sizeof( int );	/* no padding! */

	cmsg = CMSG_FIRSTHDR( &msg );
# else
	msg.msg_accrights = (char *)&fd;
	msg.msg_accrightslen = sizeof(fd);
# endif

	/*
	 * AIX returns a bogus file descriptor if recvmsg() is
	 * called with MSG_PEEK (is this a bug?). Hence we need
	 * to receive the Abandon PDU.
	 */
	err = recvmsg( s, &msg, MSG_WAITALL );
	if( err >= 0 &&
# ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
	    cmsg->cmsg_len == CMSG_LEN( sizeof(int) ) &&
	    cmsg->cmsg_level == SOL_SOCKET &&
	    cmsg->cmsg_type == SCM_RIGHTS
# else
		msg.msg_accrightslen == sizeof(int)
# endif /* HAVE_STRUCT_MSGHDR_MSG_CONTROL*/
	) {
		int mode = S_IFIFO|S_ISUID|S_IRWXU;

		/* We must receive a valid descriptor, it must be a pipe,
		 * it must only be accessible by its owner, and it must
		 * have the name of our socket written on it.
		 */
		peerbv->bv_len = err;
# ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
		fd = (*(int *)CMSG_DATA( cmsg ));
# endif
		err = fstat( fd, &st );
		if ( err == 0 )
			rlen = read(fd, &rname, rlen);
		close(fd);
		if( err == 0 && st.st_mode == mode &&
			llen == rlen && !memcmp(&lname, &rname, llen))
		{
			*euid = st.st_uid;
			*egid = st.st_gid;
			return 0;
		}
	}
#elif defined(SOCKCREDSIZE)
	struct msghdr msg;
	ber_socklen_t crmsgsize;
	void *crmsg;
	struct cmsghdr *cmp;
	struct sockcred *sc;

	memset(&msg, 0, sizeof msg);
	crmsgsize = CMSG_SPACE(SOCKCREDSIZE(NGROUPS));
	if (crmsgsize == 0) goto sc_err;
	crmsg = malloc(crmsgsize);
	if (crmsg == NULL) goto sc_err;
	memset(crmsg, 0, crmsgsize);
	
	msg.msg_control = crmsg;
	msg.msg_controllen = crmsgsize;
	
	if (recvmsg(s, &msg, 0) < 0) {
		free(crmsg);
		goto sc_err;
	}	

	if (msg.msg_controllen == 0 || (msg.msg_flags & MSG_CTRUNC) != 0) {
		free(crmsg);
		goto sc_err;
	}	
	
	cmp = CMSG_FIRSTHDR(&msg);
	if (cmp->cmsg_level != SOL_SOCKET || cmp->cmsg_type != SCM_CREDS) {
		printf("nocreds\n");
		goto sc_err;
	}	
	
	sc = (struct sockcred *)(void *)CMSG_DATA(cmp);
	
	*euid = sc->sc_euid;
	*egid = sc->sc_egid;

	free(crmsg);
	return 0;

sc_err:	
#endif
#endif /* LDAP_PF_LOCAL */

	return -1;
}

#endif /* HAVE_GETPEEREID */