1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright Amazon.com Inc. or its affiliates. */
3
4 #define _GNU_SOURCE
5 #include <sched.h>
6
7 #include <unistd.h>
8 #include <linux/netlink.h>
9 #include <linux/rtnetlink.h>
10 #include <linux/sock_diag.h>
11 #include <linux/unix_diag.h>
12 #include <sys/socket.h>
13 #include <sys/stat.h>
14 #include <sys/types.h>
15 #include <sys/un.h>
16
17 #include "../../kselftest_harness.h"
18
19 FIXTURE(diag_uid)
20 {
21 int netlink_fd;
22 int unix_fd;
23 __u32 inode;
24 __u64 cookie;
25 };
26
27 FIXTURE_VARIANT(diag_uid)
28 {
29 int unshare;
30 int udiag_show;
31 };
32
33 FIXTURE_VARIANT_ADD(diag_uid, uid)
34 {
35 .unshare = 0,
36 .udiag_show = UDIAG_SHOW_UID
37 };
38
39 FIXTURE_VARIANT_ADD(diag_uid, uid_unshare)
40 {
41 .unshare = CLONE_NEWUSER,
42 .udiag_show = UDIAG_SHOW_UID
43 };
44
45 FIXTURE_SETUP(diag_uid)
46 {
47 struct stat file_stat;
48 socklen_t optlen;
49 int ret;
50
51 if (variant->unshare)
52 ASSERT_EQ(unshare(variant->unshare), 0);
53
54 self->netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG);
55 ASSERT_NE(self->netlink_fd, -1);
56
57 self->unix_fd = socket(AF_UNIX, SOCK_STREAM, 0);
58 ASSERT_NE(self->unix_fd, -1);
59
60 ret = fstat(self->unix_fd, &file_stat);
61 ASSERT_EQ(ret, 0);
62
63 self->inode = file_stat.st_ino;
64
65 optlen = sizeof(self->cookie);
66 ret = getsockopt(self->unix_fd, SOL_SOCKET, SO_COOKIE, &self->cookie, &optlen);
67 ASSERT_EQ(ret, 0);
68 }
69
70 FIXTURE_TEARDOWN(diag_uid)
71 {
72 close(self->netlink_fd);
73 close(self->unix_fd);
74 }
75
76 int send_request(struct __test_metadata *_metadata,
77 FIXTURE_DATA(diag_uid) *self,
78 const FIXTURE_VARIANT(diag_uid) *variant)
79 {
80 struct {
81 struct nlmsghdr nlh;
82 struct unix_diag_req udr;
83 } req = {
84 .nlh = {
85 .nlmsg_len = sizeof(req),
86 .nlmsg_type = SOCK_DIAG_BY_FAMILY,
87 .nlmsg_flags = NLM_F_REQUEST
88 },
89 .udr = {
90 .sdiag_family = AF_UNIX,
91 .udiag_ino = self->inode,
92 .udiag_cookie = {
93 (__u32)self->cookie,
94 (__u32)(self->cookie >> 32)
95 },
96 .udiag_show = variant->udiag_show
97 }
98 };
99 struct sockaddr_nl nladdr = {
100 .nl_family = AF_NETLINK
101 };
102 struct iovec iov = {
103 .iov_base = &req,
104 .iov_len = sizeof(req)
105 };
106 struct msghdr msg = {
107 .msg_name = &nladdr,
108 .msg_namelen = sizeof(nladdr),
109 .msg_iov = &iov,
110 .msg_iovlen = 1
111 };
112
113 return sendmsg(self->netlink_fd, &msg, 0);
114 }
115
116 void render_response(struct __test_metadata *_metadata,
117 struct unix_diag_req *udr, __u32 len)
118 {
119 unsigned int rta_len = len - NLMSG_LENGTH(sizeof(*udr));
120 struct rtattr *attr;
121 uid_t uid;
122
123 ASSERT_GT(len, sizeof(*udr));
124 ASSERT_EQ(udr->sdiag_family, AF_UNIX);
125
126 attr = (struct rtattr *)(udr + 1);
127 ASSERT_NE(RTA_OK(attr, rta_len), 0);
128 ASSERT_EQ(attr->rta_type, UNIX_DIAG_UID);
129
130 uid = *(uid_t *)RTA_DATA(attr);
131 ASSERT_EQ(uid, getuid());
132 }
133
134 void receive_response(struct __test_metadata *_metadata,
135 FIXTURE_DATA(diag_uid) *self)
136 {
137 long buf[8192 / sizeof(long)];
138 struct sockaddr_nl nladdr = {
139 .nl_family = AF_NETLINK
140 };
141 struct iovec iov = {
142 .iov_base = buf,
143 .iov_len = sizeof(buf)
144 };
145 struct msghdr msg = {
146 .msg_name = &nladdr,
147 .msg_namelen = sizeof(nladdr),
148 .msg_iov = &iov,
149 .msg_iovlen = 1
150 };
151 struct nlmsghdr *nlh;
152 int ret;
153
154 ret = recvmsg(self->netlink_fd, &msg, 0);
155 ASSERT_GT(ret, 0);
156
157 nlh = (struct nlmsghdr *)buf;
158 ASSERT_NE(NLMSG_OK(nlh, ret), 0);
159 ASSERT_EQ(nlh->nlmsg_type, SOCK_DIAG_BY_FAMILY);
160
161 render_response(_metadata, NLMSG_DATA(nlh), nlh->nlmsg_len);
162
163 nlh = NLMSG_NEXT(nlh, ret);
164 ASSERT_EQ(NLMSG_OK(nlh, ret), 0);
165 }
166
167 TEST_F(diag_uid, 1)
168 {
169 int ret;
170
171 ret = send_request(_metadata, self, variant);
172 ASSERT_GT(ret, 0);
173
174 receive_response(_metadata, self);
175 }
176
177 TEST_HARNESS_MAIN
178
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