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ifenslave.c 18 KB

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  1. /* Mode: C;
  2. *
  3. * Mini ifenslave implementation for busybox
  4. * Copyright (C) 2005 by Marc Leeman <marc.leeman@barco.com>
  5. *
  6. * ifenslave.c: Configure network interfaces for parallel routing.
  7. *
  8. * This program controls the Linux implementation of running multiple
  9. * network interfaces in parallel.
  10. *
  11. * Author: Donald Becker <becker@cesdis.gsfc.nasa.gov>
  12. * Copyright 1994-1996 Donald Becker
  13. *
  14. * This program is free software; you can redistribute it
  15. * and/or modify it under the terms of the GNU General Public
  16. * License as published by the Free Software Foundation.
  17. *
  18. * The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
  19. * Center of Excellence in Space Data and Information Sciences
  20. * Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
  21. *
  22. * Changes :
  23. * - 2000/10/02 Willy Tarreau <willy at meta-x.org> :
  24. * - few fixes. Master's MAC address is now correctly taken from
  25. * the first device when not previously set ;
  26. * - detach support : call BOND_RELEASE to detach an enslaved interface.
  27. * - give a mini-howto from command-line help : # ifenslave -h
  28. *
  29. * - 2001/02/16 Chad N. Tindel <ctindel at ieee dot org> :
  30. * - Master is now brought down before setting the MAC address. In
  31. * the 2.4 kernel you can't change the MAC address while the device is
  32. * up because you get EBUSY.
  33. *
  34. * - 2001/09/13 Takao Indoh <indou dot takao at jp dot fujitsu dot com>
  35. * - Added the ability to change the active interface on a mode 1 bond
  36. * at runtime.
  37. *
  38. * - 2001/10/23 Chad N. Tindel <ctindel at ieee dot org> :
  39. * - No longer set the MAC address of the master. The bond device will
  40. * take care of this itself
  41. * - Try the SIOC*** versions of the bonding ioctls before using the
  42. * old versions
  43. * - 2002/02/18 Erik Habbinga <erik_habbinga @ hp dot com> :
  44. * - ifr2.ifr_flags was not initialized in the hwaddr_notset case,
  45. * SIOCGIFFLAGS now called before hwaddr_notset test
  46. *
  47. * - 2002/10/31 Tony Cureington <tony.cureington * hp_com> :
  48. * - If the master does not have a hardware address when the first slave
  49. * is enslaved, the master is assigned the hardware address of that
  50. * slave - there is a comment in bonding.c stating "ifenslave takes
  51. * care of this now." This corrects the problem of slaves having
  52. * different hardware addresses in active-backup mode when
  53. * multiple interfaces are specified on a single ifenslave command
  54. * (ifenslave bond0 eth0 eth1).
  55. *
  56. * - 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
  57. * Shmulik Hen <shmulik.hen at intel dot com>
  58. * - Moved setting the slave's mac address and opening it, from
  59. * the application to the driver. This enables support of modes
  60. * that need to use the unique mac address of each slave.
  61. * The driver also takes care of closing the slave and restoring its
  62. * original mac address upon release.
  63. * In addition, block possibility of enslaving before the master is up.
  64. * This prevents putting the system in an undefined state.
  65. *
  66. * - 2003/05/01 - Amir Noam <amir.noam at intel dot com>
  67. * - Added ABI version control to restore compatibility between
  68. * new/old ifenslave and new/old bonding.
  69. * - Prevent adding an adapter that is already a slave.
  70. * Fixes the problem of stalling the transmission and leaving
  71. * the slave in a down state.
  72. *
  73. * - 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
  74. * - Prevent enslaving if the bond device is down.
  75. * Fixes the problem of leaving the system in unstable state and
  76. * halting when trying to remove the module.
  77. * - Close socket on all abnormal exists.
  78. * - Add versioning scheme that follows that of the bonding driver.
  79. * current version is 1.0.0 as a base line.
  80. *
  81. * - 2003/05/22 - Jay Vosburgh <fubar at us dot ibm dot com>
  82. * - ifenslave -c was broken; it's now fixed
  83. * - Fixed problem with routes vanishing from master during enslave
  84. * processing.
  85. *
  86. * - 2003/05/27 - Amir Noam <amir.noam at intel dot com>
  87. * - Fix backward compatibility issues:
  88. * For drivers not using ABI versions, slave was set down while
  89. * it should be left up before enslaving.
  90. * Also, master was not set down and the default set_mac_address()
  91. * would fail and generate an error message in the system log.
  92. * - For opt_c: slave should not be set to the master's setting
  93. * while it is running. It was already set during enslave. To
  94. * simplify things, it is now handeled separately.
  95. *
  96. * - 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
  97. * - Code cleanup and style changes
  98. * set version to 1.1.0
  99. */
  100. //config:config IFENSLAVE
  101. //config: bool "ifenslave (13 kb)"
  102. //config: default y
  103. //config: select PLATFORM_LINUX
  104. //config: help
  105. //config: Userspace application to bind several interfaces
  106. //config: to a logical interface (use with kernel bonding driver).
  107. //applet:IF_IFENSLAVE(APPLET_NOEXEC(ifenslave, ifenslave, BB_DIR_SBIN, BB_SUID_DROP, ifenslave))
  108. //kbuild:lib-$(CONFIG_IFENSLAVE) += ifenslave.o interface.o
  109. //usage:#define ifenslave_trivial_usage
  110. //usage: "[-cdf] MASTER_IFACE SLAVE_IFACE..."
  111. //usage:#define ifenslave_full_usage "\n\n"
  112. //usage: "Configure network interfaces for parallel routing\n"
  113. //usage: "\n -c Change active slave"
  114. //usage: "\n -d Remove slave interface from bonding device"
  115. //usage: "\n -f Force, even if interface is not Ethernet"
  116. /* //usage: "\n -r Create a receive-only slave" */
  117. //usage:
  118. //usage:#define ifenslave_example_usage
  119. //usage: "To create a bond device, simply follow these three steps:\n"
  120. //usage: "- ensure that the required drivers are properly loaded:\n"
  121. //usage: " # modprobe bonding ; modprobe <3c59x|eepro100|pcnet32|tulip|...>\n"
  122. //usage: "- assign an IP address to the bond device:\n"
  123. //usage: " # ifconfig bond0 <addr> netmask <mask> broadcast <bcast>\n"
  124. //usage: "- attach all the interfaces you need to the bond device:\n"
  125. //usage: " # ifenslave bond0 eth0 eth1 eth2\n"
  126. //usage: " If bond0 didn't have a MAC address, it will take eth0's. Then, all\n"
  127. //usage: " interfaces attached AFTER this assignment will get the same MAC addr.\n\n"
  128. //usage: " To detach a dead interface without setting the bond device down:\n"
  129. //usage: " # ifenslave -d bond0 eth1\n\n"
  130. //usage: " To set the bond device down and automatically release all the slaves:\n"
  131. //usage: " # ifconfig bond0 down\n\n"
  132. //usage: " To change active slave:\n"
  133. //usage: " # ifenslave -c bond0 eth0\n"
  134. #include "libbb.h"
  135. /* #include <net/if.h> - no. linux/if_bonding.h pulls in linux/if.h */
  136. #include <linux/if.h>
  137. //#include <net/if_arp.h> - not needed?
  138. #include <linux/if_bonding.h>
  139. #include <linux/sockios.h>
  140. #include "fix_u32.h" /* hack, so we may include kernel's ethtool.h */
  141. #include <linux/ethtool.h>
  142. #ifndef BOND_ABI_VERSION
  143. # define BOND_ABI_VERSION 2
  144. #endif
  145. #ifndef IFNAMSIZ
  146. # define IFNAMSIZ 16
  147. #endif
  148. struct dev_data {
  149. struct ifreq mtu, flags, hwaddr;
  150. };
  151. enum { skfd = 3 }; /* AF_INET socket for ioctl() calls. */
  152. struct globals {
  153. unsigned abi_ver; /* userland - kernel ABI version */
  154. smallint hwaddr_set; /* Master's hwaddr is set */
  155. struct dev_data master;
  156. struct dev_data slave;
  157. };
  158. #define G (*ptr_to_globals)
  159. #define abi_ver (G.abi_ver )
  160. #define hwaddr_set (G.hwaddr_set)
  161. #define master (G.master )
  162. #define slave (G.slave )
  163. #define INIT_G() do { \
  164. SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
  165. } while (0)
  166. /* NOINLINEs are placed where it results in smaller code (gcc 4.3.1) */
  167. static int ioctl_on_skfd(unsigned request, struct ifreq *ifr)
  168. {
  169. return ioctl(skfd, request, ifr);
  170. }
  171. static int set_ifrname_and_do_ioctl(unsigned request, struct ifreq *ifr, const char *ifname)
  172. {
  173. strncpy_IFNAMSIZ(ifr->ifr_name, ifname);
  174. return ioctl_on_skfd(request, ifr);
  175. }
  176. static int get_if_settings(char *ifname, struct dev_data *dd)
  177. {
  178. int res;
  179. res = set_ifrname_and_do_ioctl(SIOCGIFMTU, &dd->mtu, ifname);
  180. res |= set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &dd->flags, ifname);
  181. res |= set_ifrname_and_do_ioctl(SIOCGIFHWADDR, &dd->hwaddr, ifname);
  182. return res;
  183. }
  184. static int get_slave_flags(char *slave_ifname)
  185. {
  186. return set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &slave.flags, slave_ifname);
  187. }
  188. static int set_hwaddr(char *ifname, struct sockaddr *hwaddr)
  189. {
  190. struct ifreq ifr;
  191. memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(*hwaddr));
  192. return set_ifrname_and_do_ioctl(SIOCSIFHWADDR, &ifr, ifname);
  193. }
  194. static int set_mtu(char *ifname, int mtu)
  195. {
  196. struct ifreq ifr;
  197. ifr.ifr_mtu = mtu;
  198. return set_ifrname_and_do_ioctl(SIOCSIFMTU, &ifr, ifname);
  199. }
  200. static int set_if_flags(char *ifname, int flags)
  201. {
  202. struct ifreq ifr;
  203. ifr.ifr_flags = flags;
  204. return set_ifrname_and_do_ioctl(SIOCSIFFLAGS, &ifr, ifname);
  205. }
  206. static int set_if_up(char *ifname, int flags)
  207. {
  208. int res = set_if_flags(ifname, flags | IFF_UP);
  209. if (res)
  210. bb_perror_msg("%s: can't up", ifname);
  211. return res;
  212. }
  213. static int set_if_down(char *ifname, int flags)
  214. {
  215. int res = set_if_flags(ifname, flags & ~IFF_UP);
  216. if (res)
  217. bb_perror_msg("%s: can't down", ifname);
  218. return res;
  219. }
  220. static int clear_if_addr(char *ifname)
  221. {
  222. struct ifreq ifr;
  223. ifr.ifr_addr.sa_family = AF_INET;
  224. memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
  225. return set_ifrname_and_do_ioctl(SIOCSIFADDR, &ifr, ifname);
  226. }
  227. static int set_if_addr(char *master_ifname, char *slave_ifname)
  228. {
  229. #if (SIOCGIFADDR | SIOCSIFADDR \
  230. | SIOCGIFDSTADDR | SIOCSIFDSTADDR \
  231. | SIOCGIFBRDADDR | SIOCSIFBRDADDR \
  232. | SIOCGIFNETMASK | SIOCSIFNETMASK) <= 0xffff
  233. #define INT uint16_t
  234. #else
  235. #define INT int
  236. #endif
  237. static const struct {
  238. INT g_ioctl;
  239. INT s_ioctl;
  240. } ifra[] = {
  241. { SIOCGIFADDR, SIOCSIFADDR },
  242. { SIOCGIFDSTADDR, SIOCSIFDSTADDR },
  243. { SIOCGIFBRDADDR, SIOCSIFBRDADDR },
  244. { SIOCGIFNETMASK, SIOCSIFNETMASK },
  245. };
  246. struct ifreq ifr;
  247. int res;
  248. unsigned i;
  249. for (i = 0; i < ARRAY_SIZE(ifra); i++) {
  250. res = set_ifrname_and_do_ioctl(ifra[i].g_ioctl, &ifr, master_ifname);
  251. if (res < 0) {
  252. ifr.ifr_addr.sa_family = AF_INET;
  253. memset(ifr.ifr_addr.sa_data, 0,
  254. sizeof(ifr.ifr_addr.sa_data));
  255. }
  256. res = set_ifrname_and_do_ioctl(ifra[i].s_ioctl, &ifr, slave_ifname);
  257. if (res < 0)
  258. return res;
  259. }
  260. return 0;
  261. }
  262. static void change_active(char *master_ifname, char *slave_ifname)
  263. {
  264. struct ifreq ifr;
  265. if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
  266. bb_error_msg_and_die("%s is not a slave", slave_ifname);
  267. }
  268. strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
  269. if (set_ifrname_and_do_ioctl(SIOCBONDCHANGEACTIVE, &ifr, master_ifname)
  270. && ioctl_on_skfd(BOND_CHANGE_ACTIVE_OLD, &ifr)
  271. ) {
  272. bb_perror_msg_and_die(
  273. "master %s, slave %s: can't "
  274. "change active",
  275. master_ifname, slave_ifname);
  276. }
  277. }
  278. static NOINLINE int enslave(char *master_ifname, char *slave_ifname)
  279. {
  280. struct ifreq ifr;
  281. int res;
  282. if (slave.flags.ifr_flags & IFF_SLAVE) {
  283. bb_error_msg(
  284. "%s is already a slave",
  285. slave_ifname);
  286. return 1;
  287. }
  288. res = set_if_down(slave_ifname, slave.flags.ifr_flags);
  289. if (res)
  290. return res;
  291. if (abi_ver < 2) {
  292. /* Older bonding versions would panic if the slave has no IP
  293. * address, so get the IP setting from the master.
  294. */
  295. res = set_if_addr(master_ifname, slave_ifname);
  296. if (res) {
  297. bb_perror_msg("%s: can't set address", slave_ifname);
  298. return res;
  299. }
  300. } else {
  301. res = clear_if_addr(slave_ifname);
  302. if (res) {
  303. bb_perror_msg("%s: can't clear address", slave_ifname);
  304. return res;
  305. }
  306. }
  307. if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
  308. res = set_mtu(slave_ifname, master.mtu.ifr_mtu);
  309. if (res) {
  310. bb_perror_msg("%s: can't set MTU", slave_ifname);
  311. return res;
  312. }
  313. }
  314. if (hwaddr_set) {
  315. /* Master already has an hwaddr
  316. * so set it's hwaddr to the slave
  317. */
  318. if (abi_ver < 1) {
  319. /* The driver is using an old ABI, so
  320. * the application sets the slave's
  321. * hwaddr
  322. */
  323. if (set_hwaddr(slave_ifname, &(master.hwaddr.ifr_hwaddr))) {
  324. bb_perror_msg("%s: can't set hw address",
  325. slave_ifname);
  326. goto undo_mtu;
  327. }
  328. /* For old ABI the application needs to bring the
  329. * slave back up
  330. */
  331. if (set_if_up(slave_ifname, slave.flags.ifr_flags))
  332. goto undo_slave_mac;
  333. }
  334. /* The driver is using a new ABI,
  335. * so the driver takes care of setting
  336. * the slave's hwaddr and bringing
  337. * it up again
  338. */
  339. } else {
  340. /* No hwaddr for master yet, so
  341. * set the slave's hwaddr to it
  342. */
  343. if (abi_ver < 1) {
  344. /* For old ABI, the master needs to be
  345. * down before setting it's hwaddr
  346. */
  347. if (set_if_down(master_ifname, master.flags.ifr_flags))
  348. goto undo_mtu;
  349. }
  350. if (set_hwaddr(master_ifname, &(slave.hwaddr.ifr_hwaddr))) {
  351. bb_error_msg("%s: can't set hw address",
  352. master_ifname);
  353. goto undo_mtu;
  354. }
  355. if (abi_ver < 1) {
  356. /* For old ABI, bring the master
  357. * back up
  358. */
  359. if (set_if_up(master_ifname, master.flags.ifr_flags))
  360. goto undo_master_mac;
  361. }
  362. hwaddr_set = 1;
  363. }
  364. /* Do the real thing */
  365. strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
  366. if (set_ifrname_and_do_ioctl(SIOCBONDENSLAVE, &ifr, master_ifname)
  367. && ioctl_on_skfd(BOND_ENSLAVE_OLD, &ifr)
  368. ) {
  369. goto undo_master_mac;
  370. }
  371. return 0;
  372. /* rollback (best effort) */
  373. undo_master_mac:
  374. set_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
  375. hwaddr_set = 0;
  376. goto undo_mtu;
  377. undo_slave_mac:
  378. set_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
  379. undo_mtu:
  380. set_mtu(slave_ifname, slave.mtu.ifr_mtu);
  381. return 1;
  382. }
  383. static int release(char *master_ifname, char *slave_ifname)
  384. {
  385. struct ifreq ifr;
  386. int res = 0;
  387. if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
  388. bb_error_msg("%s is not a slave", slave_ifname);
  389. return 1;
  390. }
  391. strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
  392. if (set_ifrname_and_do_ioctl(SIOCBONDRELEASE, &ifr, master_ifname) < 0
  393. && ioctl_on_skfd(BOND_RELEASE_OLD, &ifr) < 0
  394. ) {
  395. return 1;
  396. }
  397. if (abi_ver < 1) {
  398. /* The driver is using an old ABI, so we'll set the interface
  399. * down to avoid any conflicts due to same MAC/IP
  400. */
  401. res = set_if_down(slave_ifname, slave.flags.ifr_flags);
  402. }
  403. /* set to default mtu */
  404. set_mtu(slave_ifname, 1500);
  405. return res;
  406. }
  407. static NOINLINE void get_drv_info(char *master_ifname)
  408. {
  409. struct ifreq ifr;
  410. struct ethtool_drvinfo info;
  411. memset(&ifr, 0, sizeof(ifr));
  412. ifr.ifr_data = (caddr_t)&info;
  413. info.cmd = ETHTOOL_GDRVINFO;
  414. /* both fields are 32 bytes long (long enough) */
  415. strcpy(info.driver, "ifenslave");
  416. strcpy(info.fw_version, utoa(BOND_ABI_VERSION));
  417. if (set_ifrname_and_do_ioctl(SIOCETHTOOL, &ifr, master_ifname) < 0) {
  418. if (errno == EOPNOTSUPP)
  419. return;
  420. bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
  421. }
  422. abi_ver = bb_strtou(info.fw_version, NULL, 0);
  423. if (errno)
  424. bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
  425. }
  426. int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  427. int ifenslave_main(int argc UNUSED_PARAM, char **argv)
  428. {
  429. char *master_ifname, *slave_ifname;
  430. int rv;
  431. int res;
  432. unsigned opt;
  433. enum {
  434. OPT_c = (1 << 0),
  435. OPT_d = (1 << 1),
  436. OPT_f = (1 << 2),
  437. };
  438. INIT_G();
  439. opt = getopt32long(argv, "cdfa",
  440. "change-active\0" No_argument "c"
  441. "detach\0" No_argument "d"
  442. "force\0" No_argument "f"
  443. /* "all-interfaces\0" No_argument "a" */
  444. );
  445. argv += optind;
  446. if (opt & (opt-1)) /* Only one option can be given */
  447. bb_show_usage();
  448. master_ifname = *argv++;
  449. /* No interface names - show all interfaces. */
  450. if (!master_ifname) {
  451. display_interfaces(NULL);
  452. return EXIT_SUCCESS;
  453. }
  454. /* Open a basic socket */
  455. xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);
  456. /* Exchange abi version with bonding module */
  457. get_drv_info(master_ifname);
  458. slave_ifname = *argv++;
  459. if (!slave_ifname) {
  460. if (opt & (OPT_d|OPT_c)) {
  461. /* --change or --detach, and no slaves given -
  462. * show all interfaces. */
  463. display_interfaces(slave_ifname /* == NULL */);
  464. return 2; /* why 2? */
  465. }
  466. /* A single arg means show the
  467. * configuration for this interface
  468. */
  469. display_interfaces(master_ifname);
  470. return EXIT_SUCCESS;
  471. }
  472. if (get_if_settings(master_ifname, &master)) {
  473. /* Probably a good reason not to go on */
  474. bb_perror_msg_and_die("%s: can't get settings", master_ifname);
  475. }
  476. /* Check if master is indeed a master;
  477. * if not then fail any operation
  478. */
  479. if (!(master.flags.ifr_flags & IFF_MASTER))
  480. bb_error_msg_and_die("%s is not a master", master_ifname);
  481. /* Check if master is up; if not then fail any operation */
  482. if (!(master.flags.ifr_flags & IFF_UP))
  483. bb_error_msg_and_die("%s is not up", master_ifname);
  484. #ifdef WHY_BOTHER
  485. /* Neither -c[hange] nor -d[etach] -> it's "enslave" then;
  486. * and -f[orce] is not there too. Check that it's ethernet. */
  487. if (!(opt & (OPT_d|OPT_c|OPT_f))) {
  488. /* The family '1' is ARPHRD_ETHER for ethernet. */
  489. if (master.hwaddr.ifr_hwaddr.sa_family != 1) {
  490. bb_error_msg_and_die(
  491. "%s is not ethernet-like (-f overrides)",
  492. master_ifname);
  493. }
  494. }
  495. #endif
  496. /* Accepts only one slave */
  497. if (opt & OPT_c) {
  498. /* Change active slave */
  499. if (get_slave_flags(slave_ifname)) {
  500. bb_perror_msg_and_die(
  501. "%s: can't get flags", slave_ifname);
  502. }
  503. change_active(master_ifname, slave_ifname);
  504. return EXIT_SUCCESS;
  505. }
  506. /* Accepts multiple slaves */
  507. res = 0;
  508. do {
  509. if (opt & OPT_d) {
  510. /* Detach a slave interface from the master */
  511. rv = get_slave_flags(slave_ifname);
  512. if (rv) {
  513. /* Can't work with this slave, */
  514. /* remember the error and skip it */
  515. bb_perror_msg(
  516. "skipping %s: can't get %s",
  517. slave_ifname, "flags");
  518. res = rv;
  519. continue;
  520. }
  521. rv = release(master_ifname, slave_ifname);
  522. if (rv) {
  523. bb_perror_msg("can't release %s from %s",
  524. slave_ifname, master_ifname);
  525. res = rv;
  526. }
  527. } else {
  528. /* Attach a slave interface to the master */
  529. rv = get_if_settings(slave_ifname, &slave);
  530. if (rv) {
  531. /* Can't work with this slave, */
  532. /* remember the error and skip it */
  533. bb_perror_msg(
  534. "skipping %s: can't get %s",
  535. slave_ifname, "settings");
  536. res = rv;
  537. continue;
  538. }
  539. rv = enslave(master_ifname, slave_ifname);
  540. if (rv) {
  541. bb_perror_msg("can't enslave %s to %s",
  542. slave_ifname, master_ifname);
  543. res = rv;
  544. }
  545. }
  546. } while ((slave_ifname = *argv++) != NULL);
  547. if (ENABLE_FEATURE_CLEAN_UP) {
  548. close(skfd);
  549. }
  550. return res;
  551. }