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