1 /*
2 * Check decoding of SO_PEERCRED socket option.
3 *
4 * Copyright (c) 2017 Dmitry V. Levin <ldv@altlinux.org>
5 * Copyright (c) 2017-2018 The strace developers.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "tests.h"
32
33 #include <stddef.h>
34 #include <stdio.h>
35 #include <string.h>
36 #include <sys/socket.h>
37 #include <unistd.h>
38
39 #include "print_fields.h"
40
41 static const char *errstr;
42
43 static int
get_peercred(int fd,void * val,socklen_t * len)44 get_peercred(int fd, void *val, socklen_t *len)
45 {
46 int rc = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, val, len);
47 errstr = sprintrc(rc);
48 return rc;
49 }
50
51 static const char *
so_str(void)52 so_str(void)
53 {
54 static char buf[256];
55
56 if (!buf[0]) {
57 #if XLAT_RAW
58 snprintf(buf, sizeof(buf),
59 "%#x, %#x", SOL_SOCKET, SO_PEERCRED);
60 #elif XLAT_VERBOSE
61 snprintf(buf, sizeof(buf),
62 "%#x /* SOL_SOCKET */, %#x /* SO_PEERCRED */",
63 SOL_SOCKET, SO_PEERCRED);
64 #else
65 snprintf(buf, sizeof(buf),
66 "SOL_SOCKET, SO_PEERCRED");
67 #endif
68 }
69
70 return buf;
71 }
72
73 int
main(void)74 main(void)
75 {
76 TAIL_ALLOC_OBJECT_CONST_PTR(struct ucred, peercred);
77 TAIL_ALLOC_OBJECT_CONST_PTR(socklen_t, len);
78
79 const unsigned int sizeof_pid = sizeof(peercred->pid);
80 struct ucred *const pid = tail_alloc(sizeof_pid);
81
82 const unsigned int sizeof_pid_truncated = sizeof_pid - 1;
83 struct ucred *const pid_truncated =
84 tail_alloc(sizeof_pid_truncated);
85
86 const unsigned int sizeof_uid = offsetofend(struct ucred, uid);
87 struct ucred *const uid = tail_alloc(sizeof_uid);
88
89 const unsigned int sizeof_uid_truncated = sizeof_uid - 1;
90 struct ucred *const uid_truncated =
91 tail_alloc(sizeof_uid_truncated);
92
93 const unsigned int sizeof_gid_truncated =
94 offsetofend(struct ucred, gid) - 1;
95 struct ucred *const gid_truncated =
96 tail_alloc(sizeof_gid_truncated);
97
98 int sv[2];
99 if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv))
100 perror_msg_and_skip("socketpair AF_UNIX SOCK_STREAM");
101
102 /* classic getsockopt */
103 *len = sizeof(*peercred);
104 get_peercred(sv[0], peercred, len);
105 printf("getsockopt(%d, %s", sv[0], so_str());
106 PRINT_FIELD_D(", {", *peercred, pid);
107 PRINT_FIELD_UID(", ", *peercred, uid);
108 PRINT_FIELD_UID(", ", *peercred, gid);
109 printf("}, [%d]) = %s\n", *len, errstr);
110
111 /* getsockopt with zero optlen */
112 *len = 0;
113 get_peercred(sv[0], peercred, len);
114 printf("getsockopt(%d, %s, %p, [0]) = %s\n",
115 sv[0], so_str(), peercred, errstr);
116
117 /* getsockopt with optlen larger than necessary - shortened */
118 *len = sizeof(*peercred) + 1;
119 get_peercred(sv[0], peercred, len);
120 printf("getsockopt(%d, %s", sv[0], so_str());
121 PRINT_FIELD_D(", {", *peercred, pid);
122 PRINT_FIELD_UID(", ", *peercred, uid);
123 PRINT_FIELD_UID(", ", *peercred, gid);
124 printf("}, [%u->%d]) = %s\n",
125 (unsigned int) sizeof(*peercred) + 1, *len, errstr);
126
127 /*
128 * getsockopt with optlen less than offsetofend(struct ucred, pid):
129 * the part of struct ucred.pid is printed in hex.
130 */
131 *len = sizeof_pid_truncated;
132 get_peercred(sv[0], pid_truncated, len);
133 printf("getsockopt(%d, %s, {pid=", sv[0], so_str());
134 print_quoted_hex(pid_truncated, *len);
135 printf("}, [%d]) = %s\n", *len, errstr);
136
137 /*
138 * getsockopt with optlen equals to sizeof(struct ucred.pid):
139 * struct ucred.uid and struct ucred.gid are not printed.
140 */
141 *len = sizeof_pid;
142 get_peercred(sv[0], pid, len);
143 printf("getsockopt(%d, %s", sv[0], so_str());
144 PRINT_FIELD_D(", {", *pid, pid);
145 printf("}, [%d]) = %s\n", *len, errstr);
146
147 /*
148 * getsockopt with optlen greater than sizeof(struct ucred.pid)
149 * but smaller than offsetofend(struct ucred, uid):
150 * the part of struct ucred.uid is printed in hex.
151 */
152 *len = sizeof_uid_truncated;
153 get_peercred(sv[0], uid_truncated, len);
154 /*
155 * Copy to a properly aligned structure to avoid unaligned access
156 * to struct ucred.pid field.
157 */
158 memcpy(uid, uid_truncated, sizeof_uid_truncated);
159 printf("getsockopt(%d, %s", sv[0], so_str());
160 PRINT_FIELD_D(", {", *uid, pid);
161 printf(", uid=");
162 print_quoted_hex(&uid->uid, sizeof_uid_truncated -
163 offsetof(struct ucred, uid));
164 printf("}, [%d]) = %s\n", *len, errstr);
165
166 /*
167 * getsockopt with optlen equals to offsetofend(struct ucred, uid):
168 * struct ucred.gid is not printed.
169 */
170 *len = sizeof_uid;
171 get_peercred(sv[0], uid, len);
172 printf("getsockopt(%d, %s", sv[0], so_str());
173 PRINT_FIELD_D(", {", *uid, pid);
174 PRINT_FIELD_UID(", ", *uid, uid);
175 printf("}, [%d]) = %s\n", *len, errstr);
176
177 /*
178 * getsockopt with optlen greater than sizeof(struct ucred.uid)
179 * but smaller than offsetofend(struct ucred, gid):
180 * the part of struct ucred.gid is printed in hex.
181 */
182 *len = sizeof_gid_truncated;
183 get_peercred(sv[0], gid_truncated, len);
184 /*
185 * Copy to a properly aligned structure to avoid unaligned access
186 * to struct ucred.pid and struct ucred.uid fields.
187 */
188 memcpy(peercred, gid_truncated, sizeof_gid_truncated);
189 printf("getsockopt(%d, %s", sv[0], so_str());
190 PRINT_FIELD_D(", {", *peercred, pid);
191 PRINT_FIELD_UID(", ", *peercred, uid);
192 printf(", gid=");
193 print_quoted_hex(&peercred->gid, sizeof_gid_truncated -
194 offsetof(struct ucred, gid));
195 printf("}, [%d]) = %s\n", *len, errstr);
196
197 /* getsockopt optval EFAULT */
198 *len = sizeof(*peercred);
199 get_peercred(sv[0], &peercred->uid, len);
200 printf("getsockopt(%d, %s, %p, [%d]) = %s\n",
201 sv[0], so_str(), &peercred->uid, *len, errstr);
202
203 /* getsockopt optlen EFAULT */
204 get_peercred(sv[0], peercred, len + 1);
205 printf("getsockopt(%d, %s, %p, %p) = %s\n",
206 sv[0], so_str(), peercred, len + 1, errstr);
207
208 puts("+++ exited with 0 +++");
209 return 0;
210 }
211