tools/testing/selftests/net/af_unix/diag_uid.c

   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 unix_diag_req *udr;
 152         struct nlmsghdr *nlh;
 153         int ret;
 154
 155         ret = recvmsg(self->netlink_fd, &msg, 0);
 156         ASSERT_GT(ret, 0);
 157
 158         nlh = (struct nlmsghdr *)buf;
 159         ASSERT_NE(NLMSG_OK(nlh, ret), 0);
 160         ASSERT_EQ(nlh->nlmsg_type, SOCK_DIAG_BY_FAMILY);
 161
 162         render_response(_metadata, NLMSG_DATA(nlh), nlh->nlmsg_len);
 163
 164         nlh = NLMSG_NEXT(nlh, ret);
 165         ASSERT_EQ(NLMSG_OK(nlh, ret), 0);
 166 }
 167
 168 TEST_F(diag_uid, 1)
 169 {
 170         int ret;
 171
 172         ret = send_request(_metadata, self, variant);
 173         ASSERT_GT(ret, 0);
 174
 175         receive_response(_metadata, self);
 176 }
 177
 178 TEST_HARNESS_MAIN