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
 19FIXTURE(diag_uid)
 20{
 21	int netlink_fd;
 22	int unix_fd;
 23	__u32 inode;
 24	__u64 cookie;
 25};
 26
 27FIXTURE_VARIANT(diag_uid)
 28{
 29	int unshare;
 30	int udiag_show;
 31};
 32
 33FIXTURE_VARIANT_ADD(diag_uid, uid)
 34{
 35	.unshare = 0,
 36	.udiag_show = UDIAG_SHOW_UID
 37};
 38
 39FIXTURE_VARIANT_ADD(diag_uid, uid_unshare)
 40{
 41	.unshare = CLONE_NEWUSER,
 42	.udiag_show = UDIAG_SHOW_UID
 43};
 44
 45FIXTURE_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
 70FIXTURE_TEARDOWN(diag_uid)
 71{
 72	close(self->netlink_fd);
 73	close(self->unix_fd);
 74}
 75
 76int 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
116void 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
134void 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
167TEST_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
177TEST_HARNESS_MAIN