1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2023 Gleb Smirnoff <glebius@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/param.h> 29 #include <sys/ioctl.h> 30 #include <sys/time.h> 31 #include <sys/socket.h> 32 #include <sys/module.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <signal.h> 36 #include <stdlib.h> 37 #include <unistd.h> 38 39 #include <netlink/netlink.h> 40 #include <netlink/netlink_route.h> 41 42 #include <netinet/in.h> 43 #include <arpa/inet.h> 44 45 #include <atf-c.h> 46 47 static struct itimerval itv = { 48 .it_interval = { 0, 0 }, 49 .it_value = { 1, 0 }, /* one second */ 50 }; 51 static sig_atomic_t timer_done = 0; 52 static void 53 sigalarm(int sig __unused) 54 { 55 56 timer_done = 1; 57 } 58 59 static struct sigaction sigact = { 60 .sa_handler = sigalarm, 61 }; 62 63 static struct nlmsghdr hdr = (struct nlmsghdr) { 64 .nlmsg_type = RTM_GETLINK, 65 .nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK, 66 .nlmsg_len = sizeof(struct nlmsghdr), 67 }; 68 69 #define BUFLEN 1000 70 71 static int 72 fullsocket(void) 73 { 74 char buf[BUFLEN]; 75 socklen_t slen = sizeof(int); 76 int fd, sendspace, recvspace, sendavail, recvavail, rsize; 77 u_int cnt = 0; 78 79 ATF_REQUIRE((fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1); 80 ATF_REQUIRE(getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sendspace, 81 &slen) == 0); 82 ATF_REQUIRE(getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &recvspace, 83 &slen) == 0); 84 85 /* Check the expected size of reply on a single RTM_GETLINK. */ 86 ATF_REQUIRE(send(fd, &hdr, sizeof(hdr), 0) == sizeof(hdr)); 87 ATF_REQUIRE(recv(fd, buf, sizeof(hdr), MSG_WAITALL | MSG_PEEK) == 88 sizeof(hdr)); 89 ATF_REQUIRE(ioctl(fd, FIONREAD, &rsize) != -1); 90 91 92 /* 93 * Flood the socket with requests, without reading out the replies. 94 * While we are flooding, the kernel tries to process the requests. 95 * Kernel takes off requests from the send buffer and puts replies 96 * on receive buffer. Once the receive buffer is full it stops working 97 * on queue in the send buffer. At this point we must get a solid 98 * failure. However, if we flood faster than kernel taskqueue runs, 99 * we may get intermittent failures. 100 */ 101 do { 102 ssize_t rv; 103 104 rv = send(fd, &hdr, sizeof(hdr), MSG_DONTWAIT); 105 if (__predict_true(rv == sizeof(hdr))) 106 cnt++; 107 else { 108 ATF_REQUIRE(errno == EAGAIN); 109 ATF_REQUIRE(sizeof(hdr) * cnt > sendspace); 110 } 111 ATF_REQUIRE(ioctl(fd, FIONREAD, &recvavail) != -1); 112 ATF_REQUIRE(ioctl(fd, FIONWRITE, &sendavail) != -1); 113 } while (recvavail <= recvspace - rsize || 114 sendavail <= sendspace - sizeof(hdr)); 115 116 return (fd); 117 } 118 119 ATF_TC_WITHOUT_HEAD(overflow); 120 ATF_TC_BODY(overflow, tc) 121 { 122 char buf[BUFLEN]; 123 int fd; 124 125 fd = fullsocket(); 126 127 /* Both buffers full: block. */ 128 timer_done = 0; 129 ATF_REQUIRE(sigaction(SIGALRM, &sigact, NULL) == 0); 130 ATF_REQUIRE(setitimer(ITIMER_REAL, &itv, NULL) == 0); 131 ATF_REQUIRE(send(fd, &hdr, sizeof(hdr), 0) == -1); 132 ATF_REQUIRE(errno == EINTR); 133 ATF_REQUIRE(timer_done == 1); 134 135 /* 136 * Now, reading something from the receive buffer should wake up the 137 * taskqueue and send buffer should start getting drained. 138 */ 139 ATF_REQUIRE(recv(fd, buf, BUFLEN, 0) > sizeof(hdr)); 140 timer_done = 0; 141 ATF_REQUIRE(setitimer(ITIMER_REAL, &itv, NULL) == 0); 142 ATF_REQUIRE(send(fd, &hdr, sizeof(hdr), 0) == sizeof(hdr)); 143 ATF_REQUIRE(timer_done == 0); 144 } 145 146 ATF_TC_WITHOUT_HEAD(peek); 147 ATF_TC_BODY(peek, tc) 148 { 149 char *buf; 150 ssize_t ss, ss1; 151 int fd; 152 153 ATF_REQUIRE((fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1); 154 155 ATF_REQUIRE(send(fd, &hdr, sizeof(hdr), 0) == sizeof(hdr)); 156 ss = recv(fd, buf, 0, MSG_WAITALL | MSG_PEEK | MSG_TRUNC); 157 ATF_REQUIRE((buf = malloc(ss)) != NULL); 158 ATF_REQUIRE(recv(fd, buf, ss, MSG_WAITALL) == ss); 159 } 160 161 struct nl_control { 162 struct nlattr nla; 163 uint32_t val; 164 }; 165 166 static void 167 cmsg_check(struct msghdr *msg) 168 { 169 static pid_t pid = 0; 170 struct cmsghdr *cmsg; 171 struct nl_control *nlc; 172 173 ATF_REQUIRE((cmsg = CMSG_FIRSTHDR(msg)) != NULL); 174 ATF_REQUIRE(cmsg->cmsg_level == SOL_NETLINK); 175 ATF_REQUIRE(cmsg->cmsg_type == NETLINK_MSG_INFO); 176 nlc = (struct nl_control *)CMSG_DATA(cmsg); 177 ATF_REQUIRE(nlc[0].nla.nla_type == NLMSGINFO_ATTR_PROCESS_ID); 178 if (pid == 0) 179 pid = getpid(); 180 ATF_REQUIRE(nlc[0].val == pid); 181 ATF_REQUIRE(nlc[1].nla.nla_type == NLMSGINFO_ATTR_PORT_ID); 182 /* XXX need another test to test port id */ 183 ATF_REQUIRE(nlc[1].val == 0); 184 ATF_REQUIRE(CMSG_NXTHDR(msg, cmsg) == NULL); 185 ATF_REQUIRE((msg->msg_flags & MSG_CTRUNC) == 0); 186 } 187 188 ATF_TC_WITHOUT_HEAD(sizes); 189 ATF_TC_BODY(sizes, tc) 190 { 191 #define NLMSG_LARGE 2048 /* XXX: match kernel nl_buf */ 192 char buf[NLMSG_LARGE * 10]; 193 char cbuf[CMSG_SPACE(sizeof(struct nl_control) * 2)]; 194 struct iovec iov; 195 struct msghdr msg = { 196 .msg_iov = &iov, 197 .msg_iovlen = 1, 198 .msg_control = cbuf, 199 .msg_controllen = sizeof(cbuf), 200 }; 201 ssize_t ss; 202 int fd, size, rsize; 203 204 fd = fullsocket(); 205 206 /* 207 * Set NETLINK_MSG_INFO, so that later cmsg_check will check that any 208 * read is accompanied with control data. 209 */ 210 ATF_REQUIRE(setsockopt(fd, SOL_NETLINK, NETLINK_MSG_INFO, 211 &(int){1}, sizeof(int)) == 0); 212 213 iov = (struct iovec ){ 214 .iov_base = &hdr, 215 .iov_len = sizeof(hdr), 216 }; 217 /* Obtain size of the first message in the socket. */ 218 ss = recvmsg(fd, &msg, MSG_WAITALL | MSG_PEEK | MSG_TRUNC); 219 ATF_REQUIRE(ss == hdr.nlmsg_len); 220 /* And overall amount of data in the socket. */ 221 ATF_REQUIRE(ioctl(fd, FIONREAD, &rsize) != -1); 222 cmsg_check(&msg); 223 224 /* Zero-sized read should not affect state of the socket buffer. */ 225 ATF_REQUIRE(recv(fd, buf, 0, 0) == 0); 226 ATF_REQUIRE(ioctl(fd, FIONREAD, &size) != -1); 227 ATF_REQUIRE(size == rsize); 228 229 /* 230 * Undersized read should lose a message. This isn't exactly 231 * pronounced in the Netlink RFC, but it always says that Netlink 232 * socket is an analog of the BSD routing socket, and this is how 233 * a route(4) socket deals with undersized read. 234 */ 235 iov = (struct iovec ){ 236 .iov_base = buf, 237 .iov_len = sizeof(hdr), 238 }; 239 ATF_REQUIRE(recvmsg(fd, &msg, 0) == sizeof(hdr)); 240 ATF_REQUIRE(msg.msg_flags & MSG_TRUNC); 241 ATF_REQUIRE(hdr.nlmsg_len > sizeof(hdr)); 242 size = rsize - hdr.nlmsg_len; 243 ATF_REQUIRE(ioctl(fd, FIONREAD, &rsize) != -1); 244 ATF_REQUIRE(size == rsize); 245 cmsg_check(&msg); 246 247 /* 248 * Large read should span several nl_bufs, seeing no boundaries. 249 */ 250 iov = (struct iovec ){ 251 .iov_base = buf, 252 .iov_len = sizeof(buf) < rsize ? sizeof(buf) : rsize, 253 }; 254 ss = recvmsg(fd, &msg, 0); 255 ATF_REQUIRE(ss > NLMSG_LARGE * 9 || ss == rsize); 256 cmsg_check(&msg); 257 } 258 259 static struct nlattr * 260 nla_RTA_DST(struct nlattr *start, ssize_t len) 261 { 262 struct nlattr *nla; 263 264 for (nla = start; (char *)nla < (char *)start + len; 265 nla = (struct nlattr *)((char *)nla + NLA_ALIGN(nla->nla_len))) { 266 if (nla->nla_type == RTA_DST) 267 return (nla); 268 } 269 270 return (NULL); 271 } 272 /* 273 * Check that NETLINK_ADD_MEMBERSHIP subscribes us. Add & delete a temporary 274 * route and check if announcements came in. 275 */ 276 ATF_TC_WITHOUT_HEAD(membership); 277 ATF_TC_BODY(membership, tc) 278 { 279 struct { 280 struct nlmsghdr hdr; 281 struct rtmsg rtm; 282 struct nlattr rta_dst; 283 struct in_addr dst; 284 struct nlattr rta_oif; 285 uint32_t oif; 286 } reply, msg = { 287 .hdr.nlmsg_type = RTM_NEWROUTE, 288 .hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL, 289 .hdr.nlmsg_len = sizeof(msg), 290 .rtm.rtm_family = AF_INET, 291 .rtm.rtm_protocol = RTPROT_STATIC, 292 .rtm.rtm_type = RTN_UNICAST, 293 .rtm.rtm_dst_len = 32, 294 .rta_dst.nla_type = RTA_DST, 295 .rta_dst.nla_len = sizeof(struct in_addr) + 296 sizeof(struct nlattr), 297 .dst.s_addr = inet_addr("127.0.0.127"), 298 .rta_oif.nla_type = RTA_OIF, 299 .rta_oif.nla_len = sizeof(uint32_t) + sizeof(struct nlattr), 300 .oif = 1, 301 }; 302 struct nlattr *nla; 303 int fd; 304 305 ATF_REQUIRE((fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1); 306 ATF_REQUIRE(setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, 307 &(int){RTNLGRP_IPV4_ROUTE}, sizeof(int)) == 0); 308 309 ATF_REQUIRE(send(fd, &msg, sizeof(msg), 0) == sizeof(msg)); 310 ATF_REQUIRE(recv(fd, &reply, sizeof(reply), 0) == sizeof(reply)); 311 ATF_REQUIRE(reply.hdr.nlmsg_type == msg.hdr.nlmsg_type); 312 ATF_REQUIRE(reply.rtm.rtm_type == msg.rtm.rtm_type); 313 ATF_REQUIRE(reply.rtm.rtm_dst_len == msg.rtm.rtm_dst_len); 314 ATF_REQUIRE(nla = nla_RTA_DST(&reply.rta_dst, sizeof(reply))); 315 ATF_REQUIRE(memcmp(&msg.dst, (char *)nla + sizeof(struct nlattr), 316 sizeof(struct in_addr)) == 0); 317 318 msg.hdr.nlmsg_type = RTM_DELROUTE; 319 msg.hdr.nlmsg_len -= sizeof(struct nlattr) + sizeof(uint32_t); 320 ATF_REQUIRE(send(fd, &msg, msg.hdr.nlmsg_len, 0) == msg.hdr.nlmsg_len); 321 ATF_REQUIRE(recv(fd, &reply, sizeof(reply), 0) == sizeof(reply)); 322 ATF_REQUIRE(reply.hdr.nlmsg_type == msg.hdr.nlmsg_type); 323 ATF_REQUIRE(reply.rtm.rtm_type == msg.rtm.rtm_type); 324 ATF_REQUIRE(reply.rtm.rtm_dst_len == msg.rtm.rtm_dst_len); 325 ATF_REQUIRE(nla = nla_RTA_DST(&reply.rta_dst, sizeof(reply))); 326 ATF_REQUIRE(memcmp(&msg.dst, (char *)nla + sizeof(struct nlattr), 327 sizeof(struct in_addr)) == 0); 328 } 329 330 ATF_TP_ADD_TCS(tp) 331 { 332 if (modfind("netlink") == -1) 333 atf_tc_skip("netlink module not loaded"); 334 335 ATF_TP_ADD_TC(tp, overflow); 336 ATF_TP_ADD_TC(tp, peek); 337 ATF_TP_ADD_TC(tp, sizes); 338 ATF_TP_ADD_TC(tp, membership); 339 340 return (atf_no_error()); 341 } 342