2 * sys-str.c - System-dependent procedures for setting up
3 * PPP interfaces on systems which use the STREAMS ppp interface.
5 * Copyright (c) 1989 Carnegie Mellon University.
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by Carnegie Mellon University. The name of the
14 * University may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 static char rcsid[] = "$Id: sys-str.c,v 1.12 1994/09/16 02:18:01 paulus Exp $";
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/sockio.h>
42 #include <sys/stream.h>
43 #include <sys/stropts.h>
46 #include <net/route.h>
47 #include <net/if_arp.h>
48 #include <netinet/in.h>
52 #include <net/ppp_str.h>
55 #define ifr_mtu ifr_metric
58 #define MAXMODULES 10 /* max number of module names to save */
59 static struct modlist {
60 char modname[FMNAMESZ+1];
61 } str_modules[MAXMODULES];
62 static int str_module_count = 0;
63 static int pushed_ppp;
64 static int closed_stdio;
66 static int restore_term; /* 1 => we've munged the terminal */
67 static struct termios inittermios; /* Initial TTY termios */
70 * sys_init - System-dependent initialization.
75 openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
76 setlogmask(LOG_UPTO(LOG_INFO));
78 setlogmask(LOG_UPTO(LOG_DEBUG));
82 * note_debug_level - note a change in the debug level.
88 syslog(LOG_INFO, "Debug turned ON, Level %d", debug);
89 setlogmask(LOG_UPTO(LOG_DEBUG));
91 setlogmask(LOG_UPTO(LOG_WARNING));
96 * daemon - Detach us from the terminal session.
99 daemon(nochdir, noclose)
100 int nochdir, noclose;
104 if ((pid = fork()) < 0)
107 exit(0); /* parent dies */
112 fclose(stdin); /* don't need stdin, stdout, stderr */
121 * ppp_available - check if this kernel supports PPP.
128 fd = open("/dev/tty", O_RDONLY, 0);
130 return 1; /* can't find out - assume we have ppp */
131 ret = ioctl(fd, I_FIND, "pppasync") >= 0;
138 * establish_ppp - Turn the serial port into a ppp interface.
143 /* go through and save the name of all the modules, then pop em */
145 if (ioctl(fd, I_LOOK, str_modules[str_module_count].modname) < 0 ||
146 ioctl(fd, I_POP, 0) < 0)
148 MAINDEBUG((LOG_DEBUG, "popped stream module : %s",
149 str_modules[str_module_count].modname));
153 /* now push the async/fcs module */
154 if (ioctl(fd, I_PUSH, "pppasync") < 0) {
155 syslog(LOG_ERR, "ioctl(I_PUSH, ppp_async): %m");
158 /* push the compress module */
159 if (ioctl(fd, I_PUSH, "pppcomp") < 0) {
160 syslog(LOG_WARNING, "ioctl(I_PUSH, ppp_comp): %m");
162 /* finally, push the ppp_if module that actually handles the */
163 /* network interface */
164 if (ioctl(fd, I_PUSH, "pppif") < 0) {
165 syslog(LOG_ERR, "ioctl(I_PUSH, ppp_if): %m");
169 /* read mode, message non-discard mode */
170 if (ioctl(fd, I_SRDOPT, RMSGN) < 0) {
171 syslog(LOG_ERR, "ioctl(I_SRDOPT, RMSGN): %m");
175 * Find out which interface we were given.
176 * (ppp_if handles this ioctl)
178 if (ioctl(fd, SIOCGETU, &ifunit) < 0) {
179 syslog(LOG_ERR, "ioctl(SIOCGETU): %m");
183 /* Set debug flags in driver */
184 if (ioctl(fd, SIOCSIFDEBUG, &kdebugflag) < 0) {
185 syslog(LOG_ERR, "ioctl(SIOCSIFDEBUG): %m");
188 /* close stdin, stdout, stderr if they might refer to the device */
189 if (default_device && !closed_stdio) {
192 for (i = 0; i <= 2; ++i)
193 if (i != fd && i != s)
200 * disestablish_ppp - Restore the serial port to normal operation.
201 * It attempts to reconstruct the stream with the previously popped
202 * modules. This shouldn't call die() because it's called from die().
211 /* we can't push or pop modules after the stream has hung up */
212 str_module_count = 0;
213 restore_term = 0; /* nor can we fix up terminal settings */
219 * Check whether the link seems not to be 8-bit clean.
221 if (ioctl(fd, SIOCGIFDEBUG, (caddr_t) &flags) == 0) {
223 switch (~flags & PAI_FLAGS_HIBITS) {
225 s = "bit 7 set to 1";
228 s = "bit 7 set to 0";
230 case PAI_FLAGS_PAR_EVEN:
233 case PAI_FLAGS_PAR_ODD:
238 syslog(LOG_WARNING, "Serial link is not 8-bit clean:");
239 syslog(LOG_WARNING, "All received characters had %s", s);
244 while (ioctl(fd, I_POP, 0) == 0) /* pop any we pushed */
248 for (; str_module_count > 0; str_module_count--) {
249 if (ioctl(fd, I_PUSH, str_modules[str_module_count-1].modname)) {
251 syslog(LOG_WARNING, "str_restore: couldn't push module %s: %m",
252 str_modules[str_module_count-1].modname);
254 MAINDEBUG((LOG_INFO, "str_restore: pushed module %s",
255 str_modules[str_module_count-1].modname));
262 * List of valid speeds.
265 int speed_int, speed_val;
337 * Translate from bits/second to a speed_t.
343 struct speed *speedp;
347 for (speedp = speeds; speedp->speed_int; speedp++)
348 if (bps == speedp->speed_int)
349 return speedp->speed_val;
350 syslog(LOG_WARNING, "speed %d not supported", bps);
355 * Translate from a speed_t to bits/second.
361 struct speed *speedp;
365 for (speedp = speeds; speedp->speed_int; speedp++)
366 if (speed == speedp->speed_val)
367 return speedp->speed_int;
372 * set_up_tty: Set up the serial port on `fd' for 8 bits, no parity,
373 * at the requested speed, etc. If `local' is true, set CLOCAL
374 * regardless of whether the modem option was specified.
376 set_up_tty(fd, local)
382 if (tcgetattr(fd, &tios) < 0) {
383 syslog(LOG_ERR, "tcgetattr: %m");
390 tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL | CRTSCTS);
392 tios.c_cflag |= CRTSCTS;
394 tios.c_cflag |= CS8 | CREAD | HUPCL;
396 tios.c_cflag |= CLOCAL;
397 tios.c_iflag = IGNBRK | IGNPAR;
401 tios.c_cc[VTIME] = 0;
404 tios.c_iflag |= IXOFF;
405 tios.c_cc[VSTOP] = 0x13; /* DC3 = XOFF = ^S */
406 tios.c_cc[VSTART] = 0x11; /* DC1 = XON = ^Q */
409 speed = translate_speed(inspeed);
411 cfsetospeed(&tios, speed);
412 cfsetispeed(&tios, speed);
414 speed = cfgetospeed(&tios);
416 * We can't proceed if the serial port speed is B0,
417 * since that implies that the serial port is disabled.
420 syslog(LOG_ERR, "Baud rate for %s is 0; need explicit baud rate",
426 if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
427 syslog(LOG_ERR, "tcsetattr: %m");
431 baud_rate = inspeed = baud_rate_of(speed);
436 * restore_tty - restore the terminal to the saved settings.
442 if (tcsetattr(fd, TCSAFLUSH, &inittermios) < 0)
444 syslog(LOG_WARNING, "tcsetattr: %m");
450 * setdtr - control the DTR line on the serial port.
451 * This is called from die(), so it shouldn't call die().
456 int modembits = TIOCM_DTR;
458 ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
463 * output - Output PPP packet.
474 MAINDEBUG((LOG_WARNING, "output: unit != 0!"));
476 log_packet(p, len, "sent ");
479 str.buf = (caddr_t) p;
480 if (putmsg(fd, NULL, &str, 0) < 0) {
481 if (errno != ENXIO) {
482 syslog(LOG_ERR, "putmsg: %m");
489 * wait_input - wait for input, for a length of time specified in *timo.
492 struct timeval *timo;
497 t = timo == NULL? -1: timo->tv_sec * 1000 + timo->tv_usec / 1000;
499 pfd.events = POLLIN | POLLPRI | POLLHUP;
500 if (poll(&pfd, 1, t) < 0 && errno != EINTR) {
501 syslog(LOG_ERR, "poll: %m");
507 * read_packet - get a PPP packet from the serial device.
513 struct strbuf str, ctl;
515 unsigned char ctlbuf[16];
517 str.maxlen = MTU+DLLHEADERLEN;
518 str.buf = (caddr_t) buf;
519 ctl.maxlen = sizeof(ctlbuf);
520 ctl.buf = (caddr_t) ctlbuf;
522 len = getmsg(fd, &ctl, &str, &i);
524 if (errno == EAGAIN || errno == EWOULDBLOCK) {
527 syslog(LOG_ERR, "getmsg(fd) %m");
531 MAINDEBUG((LOG_DEBUG, "getmsg returned 0x%x",len));
533 syslog(LOG_NOTICE, "got ctrl msg len %d %x %x\n", ctl.len,
534 ctlbuf[0], ctlbuf[1]);
537 MAINDEBUG((LOG_DEBUG, "getmsg short return length %d", str.len));
546 * ppp_send_config - configure the transmit characteristics of
550 ppp_send_config(unit, mtu, asyncmap, pcomp, accomp)
558 strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
560 if (ioctl(s, SIOCSIFMTU, (caddr_t) &ifr) < 0) {
561 syslog(LOG_ERR, "ioctl(SIOCSIFMTU): %m");
565 if(ioctl(fd, SIOCSIFASYNCMAP, (caddr_t) &asyncmap) < 0) {
566 syslog(LOG_ERR, "ioctl(SIOCSIFASYNCMAP): %m");
571 if(ioctl(fd, SIOCSIFCOMPPROT, &c) < 0) {
572 syslog(LOG_ERR, "ioctl(SIOCSIFCOMPPROT): %m");
577 if(ioctl(fd, SIOCSIFCOMPAC, &c) < 0) {
578 syslog(LOG_ERR, "ioctl(SIOCSIFCOMPAC): %m");
585 * ppp_set_xaccm - set the extended transmit ACCM for the interface.
588 ppp_set_xaccm(unit, accm)
592 if (ioctl(fd, SIOCSIFXASYNCMAP, accm) < 0 && errno != ENOTTY)
593 syslog(LOG_WARNING, "ioctl(set extended ACCM): %m");
598 * ppp_recv_config - configure the receive-side characteristics of
602 ppp_recv_config(unit, mru, asyncmap, pcomp, accomp)
609 if (ioctl(fd, SIOCSIFMRU, &mru) < 0) {
610 syslog(LOG_ERR, "ioctl(SIOCSIFMRU): %m");
613 if (ioctl(fd, SIOCSIFRASYNCMAP, (caddr_t) &asyncmap) < 0) {
614 syslog(LOG_ERR, "ioctl(SIOCSIFRASYNCMAP): %m");
617 c = 2 + (pcomp? 1: 0);
618 if(ioctl(fd, SIOCSIFCOMPPROT, &c) < 0) {
619 syslog(LOG_ERR, "ioctl(SIOCSIFCOMPPROT): %m");
622 c = 2 + (accomp? 1: 0);
623 if (ioctl(fd, SIOCSIFCOMPAC, &c) < 0) {
624 syslog(LOG_ERR, "ioctl(SIOCSIFCOMPAC): %m");
629 * ccp_test - ask kernel whether a given compression method
630 * is acceptable for use.
632 ccp_test(unit, opt_ptr, opt_len, for_transmit)
633 int unit, opt_len, for_transmit;
636 struct ppp_option_data data;
638 if ((unsigned) opt_len > MAX_PPP_OPTION)
639 opt_len = MAX_PPP_OPTION;
640 data.length = opt_len;
641 data.transmit = for_transmit;
642 BCOPY(opt_ptr, data.opt_data, opt_len);
643 return ioctl(fd, SIOCSCOMPRESS, (caddr_t) &data) >= 0;
647 * ccp_flags_set - inform kernel about the current state of CCP.
650 ccp_flags_set(unit, isopen, isup)
651 int unit, isopen, isup;
655 x = (isopen? 1: 0) + (isup? 2: 0);
656 if (ioctl(fd, SIOCSIFCOMP, (caddr_t) &x) < 0 && errno != ENOTTY)
657 syslog(LOG_ERR, "ioctl (SIOCSIFCOMP): %m");
661 * ccp_fatal_error - returns 1 if decompression was disabled as a
662 * result of an error detected after decompression of a packet,
663 * 0 otherwise. This is necessary because of patent nonsense.
666 ccp_fatal_error(unit)
671 if (ioctl(fd, SIOCGIFCOMP, (caddr_t) &x) < 0) {
672 syslog(LOG_ERR, "ioctl(SIOCGIFCOMP): %m");
675 return x & CCP_FATALERROR;
679 * sifvjcomp - config tcp header compression
682 sifvjcomp(u, vjcomp, cidcomp, maxcid)
683 int u, vjcomp, cidcomp, maxcid;
687 x = (vjcomp? 1: 0) + (cidcomp? 0: 2) + (maxcid << 4);
688 if (ioctl(fd, SIOCSIFVJCOMP, (caddr_t) &x) < 0) {
689 syslog(LOG_ERR, "ioctl(SIOCSIFVJCOMP): %m");
696 * sifup - Config the interface up.
704 strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
705 if (ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
706 syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
709 ifr.ifr_flags |= IFF_UP;
710 if (ioctl(s, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
711 syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
718 * sifdown - Config the interface down.
725 strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
726 if (ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
727 syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
730 ifr.ifr_flags &= ~IFF_UP;
731 if (ioctl(s, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
732 syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
739 * SET_SA_FAMILY - initialize a struct sockaddr, setting the sa_family field.
741 #define SET_SA_FAMILY(addr, family) \
742 BZERO((char *) &(addr), sizeof(addr)); \
743 addr.sa_family = (family);
746 * sifaddr - Config the interface IP addresses and netmask.
757 strncpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
758 SET_SA_FAMILY(ifr.ifr_addr, AF_INET);
759 ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = o;
760 if (ioctl(s, SIOCSIFADDR, (caddr_t) &ifr) < 0) {
761 syslog(LOG_ERR, "ioctl(SIOCSIFADDR): %m");
764 ((struct sockaddr_in *) &ifr.ifr_dstaddr)->sin_addr.s_addr = h;
765 if (ioctl(s, SIOCSIFDSTADDR, (caddr_t) &ifr) < 0) {
766 syslog(LOG_ERR, "ioctl(SIOCSIFDSTADDR): %m");
770 ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = m;
771 syslog(LOG_INFO, "Setting interface mask to %s\n", ip_ntoa(m));
772 if (ioctl(s, SIOCSIFNETMASK, (caddr_t) &ifr) < 0) {
773 syslog(LOG_ERR, "ioctl(SIOCSIFNETMASK): %m");
781 * cifaddr - Clear the interface IP addresses, and delete routes
782 * through the interface if possible.
791 SET_SA_FAMILY(rt.rt_dst, AF_INET);
792 ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr = h;
793 SET_SA_FAMILY(rt.rt_gateway, AF_INET);
794 ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = o;
795 rt.rt_flags = RTF_HOST;
796 if (ioctl(s, SIOCDELRT, (caddr_t) &rt) < 0) {
797 syslog(LOG_ERR, "ioctl(SIOCDELRT): %m");
804 * sifdefaultroute - assign a default route through the address given.
807 sifdefaultroute(u, g)
813 SET_SA_FAMILY(rt.rt_dst, AF_INET);
814 SET_SA_FAMILY(rt.rt_gateway, AF_INET);
815 ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = g;
816 rt.rt_flags = RTF_GATEWAY;
817 if (ioctl(s, SIOCADDRT, &rt) < 0) {
818 syslog(LOG_ERR, "default route ioctl(SIOCADDRT): %m");
825 * cifdefaultroute - delete a default route through the address given.
828 cifdefaultroute(u, g)
834 SET_SA_FAMILY(rt.rt_dst, AF_INET);
835 SET_SA_FAMILY(rt.rt_gateway, AF_INET);
836 ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = g;
837 rt.rt_flags = RTF_GATEWAY;
838 if (ioctl(s, SIOCDELRT, &rt) < 0) {
839 syslog(LOG_ERR, "default route ioctl(SIOCDELRT): %m");
846 * sifproxyarp - Make a proxy ARP entry for the peer.
849 sifproxyarp(unit, hisaddr)
853 struct arpreq arpreq;
855 BZERO(&arpreq, sizeof(arpreq));
858 * Get the hardware address of an interface on the same subnet
859 * as our local address.
861 if (!get_ether_addr(hisaddr, &arpreq.arp_ha)) {
862 syslog(LOG_WARNING, "Cannot determine ethernet address for proxy ARP");
866 SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
867 ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
868 arpreq.arp_flags = ATF_PERM | ATF_PUBL;
869 if (ioctl(s, SIOCSARP, (caddr_t)&arpreq) < 0) {
870 syslog(LOG_ERR, "ioctl(SIOCSARP): %m");
878 * cifproxyarp - Delete the proxy ARP entry for the peer.
881 cifproxyarp(unit, hisaddr)
885 struct arpreq arpreq;
887 BZERO(&arpreq, sizeof(arpreq));
888 SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
889 ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
890 if (ioctl(s, SIOCDARP, (caddr_t)&arpreq) < 0) {
891 syslog(LOG_ERR, "ioctl(SIOCDARP): %m");
898 * get_ether_addr - get the hardware address of an interface on the
899 * the same subnet as ipaddr. Code borrowed from myetheraddr.c
900 * in the cslip-2.6 distribution, which is subject to the following
901 * copyright notice (which also applies to logwtmp below):
903 * Copyright (c) 1990, 1992 The Regents of the University of California.
904 * All rights reserved.
906 * Redistribution and use in source and binary forms, with or without
907 * modification, are permitted provided that: (1) source code distributions
908 * retain the above copyright notice and this paragraph in its entirety, (2)
909 * distributions including binary code include the above copyright notice and
910 * this paragraph in its entirety in the documentation or other materials
911 * provided with the distribution, and (3) all advertising materials mentioning
912 * features or use of this software display the following acknowledgement:
913 * ``This product includes software developed by the University of California,
914 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
915 * the University nor the names of its contributors may be used to endorse
916 * or promote products derived from this software without specific prior
917 * written permission.
918 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
919 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
920 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
926 #include <arpa/inet.h>
928 /* XXX SunOS 4.1 defines this and 3.5 doesn't... */
934 #include <netinet/in_var.h>
936 #include <netinet/if_ether.h>
938 /* Cast a struct sockaddr to a structaddr_in */
939 #define SATOSIN(sa) ((struct sockaddr_in *)(sa))
941 /* Determine if "bits" is set in "flag" */
942 #define ALLSET(flag, bits) (((flag) & (bits)) == (bits))
944 static struct nlist nl[] = {
953 get_ether_addr(ipaddr, hwaddr)
955 struct sockaddr *hwaddr;
958 register struct ifnet *ifp;
959 register struct arpcom *ac;
960 struct arpcom arpcom;
963 register struct ifaddr *ifa;
964 register struct in_ifaddr *in;
972 /* Open kernel memory for reading */
973 kd = kvm_open(0, 0, 0, O_RDONLY, NULL);
975 syslog(LOG_ERR, "kvm_open: %m");
980 if (kvm_nlist(kd, nl) != 0) {
981 syslog(LOG_ERR, "kvm_nlist failed");
992 if (kvm_read(kd, nl[N_IFNET].n_value, (char *)&addr, sizeof(addr))
994 syslog(LOG_ERR, "error reading ifnet addr");
997 for ( ; addr; addr = (uint32)ifp->if_next) {
998 if (kvm_read(kd, addr, (char *)ac, sizeof(*ac)) != sizeof(*ac)) {
999 syslog(LOG_ERR, "error reading ifnet");
1003 /* Only look at configured, broadcast interfaces */
1004 if (!ALLSET(ifp->if_flags, IFF_UP | IFF_BROADCAST))
1007 /* This probably can't happen... */
1008 if (ifp->if_addrlist == 0)
1012 /* Get interface ip address */
1014 if (kvm_read(kd, (uint32)ifp->if_addrlist, (char *)&ifaddr,
1015 sizeof(ifaddr)) != sizeof(ifaddr)) {
1016 syslog(LOG_ERR, "error reading ifaddr");
1019 inp = &SATOSIN(&ifa->ifa_addr)->sin_addr;
1021 inp = &SATOSIN(&ifp->if_addr)->sin_addr;
1024 /* Check if this interface on the right subnet */
1026 mask = in->ia_subnetmask;
1028 mask = ifp->if_subnetmask;
1030 if ((ipaddr & mask) != (inp->s_addr & mask))
1033 /* Copy out the local ethernet address */
1034 hwaddr->sa_family = AF_UNSPEC;
1035 BCOPY((caddr_t) &arpcom.ac_enaddr, hwaddr->sa_data,
1036 sizeof(arpcom.ac_enaddr));
1037 return 1; /* success! */
1040 /* couldn't find one */
1044 #define WTMPFILE "/usr/adm/wtmp"
1047 logwtmp(line, name, host)
1048 char *line, *name, *host;
1054 if ((fd = open(WTMPFILE, O_WRONLY|O_APPEND, 0)) < 0)
1056 if (!fstat(fd, &buf)) {
1057 (void)strncpy(ut.ut_line, line, sizeof(ut.ut_line));
1058 (void)strncpy(ut.ut_name, name, sizeof(ut.ut_name));
1059 (void)strncpy(ut.ut_host, host, sizeof(ut.ut_host));
1060 (void)time(&ut.ut_time);
1061 if (write(fd, (char *)&ut, sizeof(struct utmp)) != sizeof(struct utmp))
1062 (void)ftruncate(fd, buf.st_size);