/* * ripped off from ../ntpres/ntpres.c by Greg Troxel 4/2/92 * routine callable from ntpd, rather than separate program * also, key info passed in via a global, so no key file needed. */ /* * ntpres - process configuration entries which require use of the resolver * * This is meant to be run by ntpd on the fly. It is not guaranteed * to work properly if run by hand. This is actually a quick hack to * stave off violence from people who hate using numbers in the * configuration file (at least I hope the rest of the daemon is * better than this). Also might provide some ideas about how one * might go about autoconfiguring an NTP distribution network. * */ #ifdef HAVE_CONFIG_H # include #endif #include #include #include #include #include #include #include "ntpd.h" #include "ntp_io.h" #include "ntp_request.h" #include "ntp_stdlib.h" #include "ntp_syslog.h" #define STREQ(a, b) (*(a) == *(b) && strcmp((a), (b)) == 0) /* * Each item we are to resolve and configure gets one of these * structures defined for it. */ struct conf_entry { struct conf_entry *ce_next; char *ce_name; /* name we are trying to resolve */ struct conf_peer ce_config; /* configuration info for peer */ }; #define ce_peeraddr ce_config.peeraddr #define ce_hmode ce_config.hmode #define ce_version ce_config.version #define ce_minpoll ce_config.minpoll #define ce_maxpoll ce_config.maxpoll #define ce_flags ce_config.flags #define ce_ttl ce_config.ttl #define ce_keyid ce_config.keyid /* * confentries is a pointer to the list of configuration entries * we have left to do. */ static struct conf_entry *confentries = NULL; /* * We take an interrupt every thirty seconds, at which time we decrement * config_timer and resolve_timer. The former is set to 2, so we retry * unsucessful reconfigurations every minute. The latter is set to * an exponentially increasing value which starts at 2 and increases to * 32. When this expires we retry failed name resolutions. * * We sleep SLEEPTIME seconds before doing anything, to give the server * time to arrange itself. */ #define MINRESOLVE 2 #define MAXRESOLVE 32 #define CONFIG_TIME 2 #define ALARM_TIME 30 #define SLEEPTIME 2 static volatile int config_timer = 0; static volatile int resolve_timer = 0; static int resolve_value; /* next value of resolve timer */ /* * Big hack attack */ #define LOCALHOST 0x7f000001 /* 127.0.0.1, in hex, of course */ #define SKEWTIME 0x08000000 /* 0.03125 seconds as a l_fp fraction */ /* * Select time out. Set to 2 seconds. The server is on the local machine, * after all. */ #define TIMEOUT_SEC 2 #define TIMEOUT_USEC 0 /* * Input processing. The data on each line in the configuration file * is supposed to consist of entries in the following order */ #define TOK_HOSTNAME 0 #define TOK_HMODE 1 #define TOK_VERSION 2 #define TOK_MINPOLL 3 #define TOK_MAXPOLL 4 #define TOK_FLAGS 5 #define TOK_TTL 6 #define TOK_KEYID 7 #define NUMTOK 8 #define MAXLINESIZE 512 /* * File descriptor for ntp request code. */ static int sockfd = -1; /* stuff to be filled in by caller */ u_long req_keyid; /* request keyid */ char *req_file; /* name of the file with configuration info */ /* end stuff to be filled in */ static RETSIGTYPE bong P((int)); static void checkparent P((void)); static void removeentry P((struct conf_entry *)); static void addentry P((char *, int, int, int, int, int, int, u_long)); static int findhostaddr P((struct conf_entry *)); static void openntp P((void)); static int request P((struct conf_peer *)); static char * nexttoken P((char **)); static void readconf P((FILE *, char *)); static void doconfigure P((int)); /* * assumes: req_key, req_keyid, conffile valid * syslog still open */ void ntp_intres(void) { FILE *in; #ifdef HAVE_SIGSUSPEND sigset_t set; sigemptyset(&set); #endif /* NTP_POSIX_SOURCE */ #ifdef DEBUG if (debug) { msyslog(LOG_INFO, "NTP_INTRES running"); } #endif /* check out auth stuff */ if (sys_authenticate) { if (!authistrusted(req_keyid)) { msyslog(LOG_ERR, "invalid request keyid %lu", req_keyid ); exit(1); } } /* * Read the configuration info * {this is bogus, since we are forked, but it is easier * to keep this code - gdt} */ if ((in = fopen(req_file, "r")) == NULL) { msyslog(LOG_ERR, "can't open configuration file %s: %m", req_file); exit(1); } readconf(in, req_file); (void) fclose(in); if (!debug ) (void) unlink(req_file); /* * Sleep a little to make sure the server is completely up */ sleep(SLEEPTIME); /* * Make a first cut at resolving the bunch */ doconfigure(1); if (confentries == NULL) #if defined SYS_WINNT ExitThread(0); /* Don't want to kill whole NT process */ #else exit(0); /* done that quick */ #endif /* * Here we've got some problem children. Set up the timer * and wait for it. */ resolve_value = resolve_timer = MINRESOLVE; config_timer = CONFIG_TIME; #ifndef SYS_WINNT (void) signal_no_reset(SIGALRM, bong); alarm(ALARM_TIME); #endif /* SYS_WINNT */ for (;;) { if (confentries == NULL) exit(0); checkparent(); if (resolve_timer == 0) { if (resolve_value < MAXRESOLVE) resolve_value <<= 1; resolve_timer = resolve_value; #ifdef DEBUG msyslog(LOG_INFO, "resolve_timer: 0->%d", resolve_timer); #endif config_timer = CONFIG_TIME; doconfigure(1); continue; } else if (config_timer == 0) { config_timer = CONFIG_TIME; #ifdef DEBUG msyslog(LOG_INFO, "config_timer: 0->%d", config_timer); #endif doconfigure(0); continue; } #ifndef SYS_WINNT /* * There is a race in here. Is okay, though, since * all it does is delay things by 30 seconds. */ #ifdef HAVE_SIGSUSPEND sigsuspend(&set); #else sigpause(0); #endif /* HAVE_SIGSUSPEND */ #else if (config_timer > 0) config_timer--; if (resolve_timer > 0) resolve_timer--; sleep(ALARM_TIME); #endif /* SYS_WINNT */ } } #ifndef SYS_WINNT /* * bong - service and reschedule an alarm() interrupt */ static RETSIGTYPE bong( int sig ) { if (config_timer > 0) config_timer--; if (resolve_timer > 0) resolve_timer--; alarm(ALARM_TIME); } #endif /* SYS_WINNT */ /* * checkparent - see if our parent process is still running * * No need to worry in the Windows NT environment whether the * main thread is still running, because if it goes * down it takes the whole process down with it (in * which case we won't be running this thread either) * Turn function into NOP; */ static void checkparent(void) { #if !defined (SYS_WINNT) && !defined (SYS_VXWORKS) /* * If our parent (the server) has died we will have been * inherited by init. If so, exit. */ if (getppid() == 1) { msyslog(LOG_INFO, "parent died before we finished, exiting"); exit(0); } #endif /* SYS_WINNT && SYS_VXWORKS*/ } /* * removeentry - we are done with an entry, remove it from the list */ static void removeentry( struct conf_entry *entry ) { register struct conf_entry *ce; ce = confentries; if (ce == entry) { confentries = ce->ce_next; return; } while (ce != NULL) { if (ce->ce_next == entry) { ce->ce_next = entry->ce_next; return; } ce = ce->ce_next; } } /* * addentry - add an entry to the configuration list */ static void addentry( char *name, int mode, int version, int minpoll, int maxpoll, int flags, int ttl, u_long keyid ) { register char *cp; register struct conf_entry *ce; unsigned int len; len = strlen(name) + 1; cp = (char*)emalloc(len); memmove(cp, name, len); ce = (struct conf_entry *)emalloc(sizeof(struct conf_entry)); ce->ce_name = cp; ce->ce_peeraddr = 0; ce->ce_hmode = (u_char)mode; ce->ce_version = (u_char)version; ce->ce_minpoll = (u_char)minpoll; ce->ce_maxpoll = (u_char)maxpoll; ce->ce_flags = (u_char)flags; ce->ce_ttl = (u_char)ttl; ce->ce_keyid = keyid; ce->ce_next = NULL; if (confentries == NULL) { confentries = ce; } else { register struct conf_entry *cep; for (cep = confentries; cep->ce_next != NULL; cep = cep->ce_next) /* nothing */; cep->ce_next = ce; } } /* * findhostaddr - resolve a host name into an address * * The routine sticks the address into the entry's ce_peeraddr if it * gets one. It returns 1 for "success" and 0 for an uncorrectable * failure. Note that "success" includes try again errors. You can * tell that you got a try again since ce_peeraddr will still be zero. */ static int findhostaddr( struct conf_entry *entry ) { struct hostent *hp; checkparent(); /* make sure our guy is still running */ hp = gethostbyname(entry->ce_name); if (hp == NULL) { #ifndef NODNS /* * If the resolver is in use, see if the failure is * temporary. If so, return success. */ if (h_errno == TRY_AGAIN) return (1); #endif return (0); } /* * Use the first address. We don't have any way to * tell preferences and older gethostbyname() implementations * only return one. */ memmove((char *)&(entry->ce_peeraddr), (char *)hp->h_addr, sizeof(struct in_addr)); return (1); } /* * openntp - open a socket to the ntp server */ static void openntp(void) { struct sockaddr_in saddr; if (sockfd >= 0) return; sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (sockfd == -1) { msyslog(LOG_ERR, "socket() failed: %m"); exit(1); } memset((char *)&saddr, 0, sizeof(saddr)); saddr.sin_family = AF_INET; saddr.sin_port = htons(NTP_PORT); /* trash */ saddr.sin_addr.s_addr = htonl(LOCALHOST); /* garbage */ /* * Make the socket non-blocking. We'll wait with select() */ #ifndef SYS_WINNT #if defined(O_NONBLOCK) if (fcntl(sockfd, F_SETFL, O_NONBLOCK) == -1) { msyslog(LOG_ERR, "fcntl(O_NONBLOCK) failed: %m"); exit(1); } #else #if defined(FNDELAY) if (fcntl(sockfd, F_SETFL, FNDELAY) == -1) { msyslog(LOG_ERR, "fcntl(FNDELAY) failed: %m"); exit(1); } #else # include "Bletch: NEED NON BLOCKING IO" #endif /* FNDDELAY */ #endif /* O_NONBLOCK */ #else /* SYS_WINNT */ { int on=1; if (ioctlsocket(sockfd,FIONBIO,(u_long *) &on) == SOCKET_ERROR) { msyslog(LOG_ERR, "ioctlsocket(FIONBIO) fails: %m"); exit(1); /* Windows NT - set socket in non-blocking mode */ } } #endif /* SYS_WINNT */ if (connect(sockfd, (struct sockaddr *)&saddr, sizeof(saddr)) == -1) { msyslog(LOG_ERR, "connect() failed: %m"); exit(1); } } /* * request - send a configuration request to the server, wait for a response */ static int request( struct conf_peer *conf ) { fd_set fdset; struct timeval tvout; struct req_pkt reqpkt; l_fp ts; int n; #ifdef SYS_WINNT HANDLE hReadWriteEvent = NULL; BOOL ret; DWORD NumberOfBytesWritten, NumberOfBytesRead, dwWait; OVERLAPPED overlap; #endif /* SYS_WINNT */ checkparent(); /* make sure our guy is still running */ if (sockfd < 0) openntp(); #ifdef SYS_WINNT hReadWriteEvent = CreateEvent(NULL, FALSE, FALSE, NULL); #endif /* SYS_WINNT */ /* * Try to clear out any previously received traffic so it * doesn't fool us. Note the socket is nonblocking. */ tvout.tv_sec = 0; tvout.tv_usec = 0; FD_ZERO(&fdset); FD_SET(sockfd, &fdset); while (select(sockfd + 1, &fdset, (fd_set *)0, (fd_set *)0, &tvout) > 0) { recv(sockfd, (char *)&reqpkt, REQ_LEN_MAC, 0); FD_ZERO(&fdset); FD_SET(sockfd, &fdset); } /* * Make up a request packet with the configuration info */ memset((char *)&reqpkt, 0, sizeof(reqpkt)); reqpkt.rm_vn_mode = RM_VN_MODE(0, 0, 0); reqpkt.auth_seq = AUTH_SEQ(1, 0); /* authenticated, no seq */ reqpkt.implementation = IMPL_XNTPD; /* local implementation */ reqpkt.request = REQ_CONFIG; /* configure a new peer */ reqpkt.err_nitems = ERR_NITEMS(0, 1); /* one item */ reqpkt.mbz_itemsize = MBZ_ITEMSIZE(sizeof(struct conf_peer)); memmove(reqpkt.data, (char *)conf, sizeof(struct conf_peer)); reqpkt.keyid = htonl(req_keyid); get_systime(&ts); L_ADDUF(&ts, SKEWTIME); HTONL_FP(&ts, &reqpkt.tstamp); n = 0; if (sys_authenticate) n = authencrypt(req_keyid, (u_int32 *)&reqpkt, REQ_LEN_NOMAC); /* * Done. Send it. */ #ifndef SYS_WINNT n = send(sockfd, (char *)&reqpkt, (unsigned)(REQ_LEN_NOMAC + n), 0); if (n < 0) { msyslog(LOG_ERR, "send to NTP server failed: %m"); return 0; /* maybe should exit */ } #else /* In the NT world, documentation seems to indicate that there * exist _write and _read routines that can be used to so blocking * I/O on sockets. Problem is these routines require a socket * handle obtained through the _open_osf_handle C run-time API * of which there is no explanation in the documentation. We need * nonblocking write's and read's anyway for our purpose here. * We're therefore forced to deviate a little bit from the Unix * model here and use the ReadFile and WriteFile Win32 I/O API's * on the socket */ overlap.Offset = overlap.OffsetHigh = (DWORD)0; overlap.hEvent = hReadWriteEvent; ret = WriteFile((HANDLE)sockfd, (char *)&reqpkt, REQ_LEN_NOMAC + n, (LPDWORD)&NumberOfBytesWritten, (LPOVERLAPPED)&overlap); if ((ret == FALSE) && (GetLastError() != ERROR_IO_PENDING)) { msyslog(LOG_ERR, "send to NTP server failed: %m"); return 0; } dwWait = WaitForSingleObject(hReadWriteEvent, (DWORD) TIMEOUT_SEC * 1000); if ((dwWait == WAIT_FAILED) || (dwWait == WAIT_TIMEOUT)) { if (dwWait == WAIT_FAILED) msyslog(LOG_ERR, "WaitForSingleObject failed: %m"); return 0; } #endif /* SYS_WINNT */ /* * Wait for a response. A weakness of the mode 7 protocol used * is that there is no way to associate a response with a * particular request, i.e. the response to this configuration * request is indistinguishable from that to any other. I should * fix this some day. In any event, the time out is fairly * pessimistic to make sure that if an answer is coming back * at all, we get it. */ for (;;) { FD_ZERO(&fdset); FD_SET(sockfd, &fdset); tvout.tv_sec = TIMEOUT_SEC; tvout.tv_usec = TIMEOUT_USEC; n = select(sockfd + 1, &fdset, (fd_set *)0, (fd_set *)0, &tvout); if (n < 0) { msyslog(LOG_ERR, "select() fails: %m"); return 0; } else if (n == 0) { if(debug) msyslog(LOG_DEBUG, "select() returned 0."); return 0; } #ifndef SYS_WINNT n = recv(sockfd, (char *)&reqpkt, REQ_LEN_MAC, 0); if (n <= 0) { if (n < 0) { msyslog(LOG_ERR, "recv() fails: %m"); return 0; } continue; } #else /* Overlapped I/O used on non-blocking sockets on Windows NT */ ret = ReadFile((HANDLE)sockfd, (char *)&reqpkt, (DWORD)REQ_LEN_MAC, (LPDWORD)&NumberOfBytesRead, (LPOVERLAPPED)&overlap); if ((ret == FALSE) && (GetLastError() != ERROR_IO_PENDING)) { msyslog(LOG_ERR, "ReadFile() fails: %m"); return 0; } dwWait = WaitForSingleObject(hReadWriteEvent, (DWORD) TIMEOUT_SEC * 1000); if ((dwWait == WAIT_FAILED) || (dwWait == WAIT_TIMEOUT)) { if (dwWait == WAIT_FAILED) { msyslog(LOG_ERR, "WaitForSingleObject fails: %m"); return 0; } continue; } n = NumberOfBytesRead; #endif /* SYS_WINNT */ /* * Got one. Check through to make sure it is what * we expect. */ if (n < RESP_HEADER_SIZE) { msyslog(LOG_ERR, "received runt response (%d octets)", n); continue; } if (!ISRESPONSE(reqpkt.rm_vn_mode)) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "received non-response packet"); #endif continue; } if (ISMORE(reqpkt.rm_vn_mode)) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "received fragmented packet"); #endif continue; } if ( ( (INFO_VERSION(reqpkt.rm_vn_mode) < 2) || (INFO_VERSION(reqpkt.rm_vn_mode) > NTP_VERSION)) || INFO_MODE(reqpkt.rm_vn_mode) != MODE_PRIVATE) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "version (%d/%d) or mode (%d/%d) incorrect", INFO_VERSION(reqpkt.rm_vn_mode), NTP_VERSION, INFO_MODE(reqpkt.rm_vn_mode), MODE_PRIVATE); #endif continue; } if (INFO_SEQ(reqpkt.auth_seq) != 0) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "nonzero sequence number (%d)", INFO_SEQ(reqpkt.auth_seq)); #endif continue; } if (reqpkt.implementation != IMPL_XNTPD || reqpkt.request != REQ_CONFIG) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "implementation (%d) or request (%d) incorrect", reqpkt.implementation, reqpkt.request); #endif continue; } if (INFO_NITEMS(reqpkt.err_nitems) != 0 || INFO_MBZ(reqpkt.mbz_itemsize) != 0 || INFO_ITEMSIZE(reqpkt.mbz_itemsize) != 0) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "nitems (%d) mbz (%d) or itemsize (%d) nonzero", INFO_NITEMS(reqpkt.err_nitems), INFO_MBZ(reqpkt.mbz_itemsize), INFO_ITEMSIZE(reqpkt.mbz_itemsize)); #endif continue; } n = INFO_ERR(reqpkt.err_nitems); switch (n) { case INFO_OKAY: /* success */ return 1; case INFO_ERR_IMPL: msyslog(LOG_ERR, "server reports implementation mismatch!!"); return 0; case INFO_ERR_REQ: msyslog(LOG_ERR, "server claims configuration request is unknown"); return 0; case INFO_ERR_FMT: msyslog(LOG_ERR, "server indicates a format error occurred(!!)"); return 0; case INFO_ERR_NODATA: msyslog(LOG_ERR, "server indicates no data available (shouldn't happen)"); return 0; case INFO_ERR_AUTH: msyslog(LOG_ERR, "server returns a permission denied error"); return 0; default: msyslog(LOG_ERR, "server returns unknown error code %d", n); return 0; } } } /* * nexttoken - return the next token from a line */ static char * nexttoken( char **lptr ) { register char *cp; register char *tstart; cp = *lptr; /* * Skip leading white space */ while (*cp == ' ' || *cp == '\t') cp++; /* * If this is the end of the line, return nothing. */ if (*cp == '\n' || *cp == '\0') { *lptr = cp; return NULL; } /* * Must be the start of a token. Record the pointer and look * for the end. */ tstart = cp++; while (*cp != ' ' && *cp != '\t' && *cp != '\n' && *cp != '\0') cp++; /* * Terminate the token with a \0. If this isn't the end of the * line, space to the next character. */ if (*cp == '\n' || *cp == '\0') *cp = '\0'; else *cp++ = '\0'; *lptr = cp; return tstart; } /* * readconf - read the configuration information out of the file we * were passed. Note that since the file is supposed to be * machine generated, we bail out at the first sign of trouble. */ static void readconf( FILE *fp, char *name ) { register int i; char *token[NUMTOK]; u_long intval[NUMTOK]; int flags; char buf[MAXLINESIZE]; char *bp; while (fgets(buf, MAXLINESIZE, fp) != NULL) { bp = buf; for (i = 0; i < NUMTOK; i++) { if ((token[i] = nexttoken(&bp)) == NULL) { msyslog(LOG_ERR, "tokenizing error in file `%s', quitting", name); exit(1); } } for (i = 1; i < NUMTOK; i++) { if (!atouint(token[i], &intval[i])) { msyslog(LOG_ERR, "format error for integer token `%s', file `%s', quitting", token[i], name); exit(1); } } if (intval[TOK_HMODE] != MODE_ACTIVE && intval[TOK_HMODE] != MODE_CLIENT && intval[TOK_HMODE] != MODE_BROADCAST) { msyslog(LOG_ERR, "invalid mode (%ld) in file %s", intval[TOK_HMODE], name); exit(1); } if (intval[TOK_VERSION] > NTP_VERSION || intval[TOK_VERSION] < NTP_OLDVERSION) { msyslog(LOG_ERR, "invalid version (%ld) in file %s", intval[TOK_VERSION], name); exit(1); } if (intval[TOK_MINPOLL] < NTP_MINPOLL || intval[TOK_MINPOLL] > NTP_MAXPOLL) { msyslog(LOG_ERR, "invalid MINPOLL value (%ld) in file %s", intval[TOK_MINPOLL], name); exit(1); } if (intval[TOK_MAXPOLL] < NTP_MINPOLL || intval[TOK_MAXPOLL] > NTP_MAXPOLL) { msyslog(LOG_ERR, "invalid MAXPOLL value (%ld) in file %s", intval[TOK_MAXPOLL], name); exit(1); } if ((intval[TOK_FLAGS] & ~(FLAG_AUTHENABLE | FLAG_PREFER | FLAG_NOSELECT | FLAG_BURST | FLAG_SKEY)) != 0) { msyslog(LOG_ERR, "invalid flags (%ld) in file %s", intval[TOK_FLAGS], name); exit(1); } flags = 0; if (intval[TOK_FLAGS] & FLAG_AUTHENABLE) flags |= CONF_FLAG_AUTHENABLE; if (intval[TOK_FLAGS] & FLAG_PREFER) flags |= CONF_FLAG_PREFER; if (intval[TOK_FLAGS] & FLAG_NOSELECT) flags |= CONF_FLAG_NOSELECT; if (intval[TOK_FLAGS] & FLAG_BURST) flags |= CONF_FLAG_BURST; if (intval[TOK_FLAGS] & FLAG_SKEY) flags |= CONF_FLAG_SKEY; /* * This is as good as we can check it. Add it in. */ addentry(token[TOK_HOSTNAME], (int)intval[TOK_HMODE], (int)intval[TOK_VERSION], (int)intval[TOK_MINPOLL], (int)intval[TOK_MAXPOLL], flags, (int)intval[TOK_TTL], intval[TOK_KEYID]); } } /* * doconfigure - attempt to resolve names and configure the server */ static void doconfigure( int dores ) { register struct conf_entry *ce; register struct conf_entry *ceremove; #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "doconfigure(%d)", dores); #endif ce = confentries; while (ce != NULL) { #ifdef DEBUG if (debug > 1) msyslog(LOG_INFO, "doconfigure: <%s> has peeraddr %#x", ce->ce_name, ce->ce_peeraddr); #endif if (dores && ce->ce_peeraddr == 0) { if (!findhostaddr(ce)) { msyslog(LOG_ERR, "couldn't resolve `%s', giving up on it", ce->ce_name); ceremove = ce; ce = ceremove->ce_next; removeentry(ceremove); continue; } #ifdef DEBUG if (debug > 1) { msyslog(LOG_INFO, "doconfigure:findhostaddr() worked"); } #endif } if (ce->ce_peeraddr != 0) { #ifdef DEBUG if (debug > 1) { msyslog(LOG_INFO, "doconfigure: calling request()"); } #endif if (request(&ce->ce_config)) { #ifdef DEBUG if (debug > 1) { msyslog(LOG_INFO, "doconfigure: request() OK, removing this entry"); } #endif ceremove = ce; ce = ceremove->ce_next; removeentry(ceremove); continue; } #ifdef DEBUG if (debug > 1) { msyslog(LOG_INFO, "doconfigure: request() FAILED, maybe next time."); } #endif } ce = ce->ce_next; } }