summaryrefslogtreecommitdiffstats
path: root/src/auth_time.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/auth_time.c495
1 files changed, 495 insertions, 0 deletions
diff --git a/src/auth_time.c b/src/auth_time.c
new file mode 100644
index 0000000..936dd76
--- /dev/null
+++ b/src/auth_time.c
@@ -0,0 +1,495 @@
+/*
+ * auth_time.c
+ *
+ * This module contains the private function __rpc_get_time_offset()
+ * which will return the difference in seconds between the local system's
+ * notion of time and a remote server's notion of time. This must be
+ * possible without calling any functions that may invoke the name
+ * service. (netdir_getbyxxx, getXbyY, etc). The function is used in the
+ * synchronize call of the authdes code to synchronize clocks between
+ * NIS+ clients and their servers.
+ *
+ * Note to minimize the amount of duplicate code, portions of the
+ * synchronize() function were folded into this code, and the synchronize
+ * call becomes simply a wrapper around this function. Further, if this
+ * function is called with a timehost it *DOES* recurse to the name
+ * server so don't use it in that mode if you are doing name service code.
+ *
+ * Copyright (c) 1992 Sun Microsystems Inc.
+ * All rights reserved.
+ *
+ * Side effects :
+ * When called a client handle to a RPCBIND process is created
+ * and destroyed. Two strings "netid" and "uaddr" are malloc'd
+ * and returned. The SIGALRM processing is modified only if
+ * needed to deal with TCP connections.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <rpc/rpc.h>
+#include <rpc/rpc_com.h>
+#include <rpc/rpcb_prot.h>
+//#include <clnt_soc.h>
+#include <sys/select.h>
+
+#include "nis.h"
+
+
+#ifdef TESTING
+#define msg(x) printf("ERROR: %s\n", x)
+/* #define msg(x) syslog(LOG_ERR, "%s", x) */
+#else
+#define msg(x)
+#endif
+
+static int saw_alarm = 0;
+
+static void
+alarm_hndler(s)
+ int s;
+{
+ saw_alarm = 1;
+ return;
+}
+
+/*
+ * The internet time server defines the epoch to be Jan 1, 1900
+ * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
+ * from internet time-service time, into UNIX time we subtract the
+ * following offset :
+ */
+#define NYEARS (1970 - 1900)
+#define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
+
+
+/*
+ * Stolen from rpc.nisd:
+ * Turn a 'universal address' into a struct sockaddr_in.
+ * Bletch.
+ */
+static int uaddr_to_sockaddr(uaddr, sin)
+#ifdef foo
+ endpoint *endpt;
+#endif
+ char *uaddr;
+ struct sockaddr_in *sin;
+{
+ unsigned char p_bytes[2];
+ int i;
+ unsigned long a[6];
+
+ i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
+ &a[3], &a[4], &a[5]);
+
+ if (i < 6)
+ return(1);
+
+ for (i = 0; i < 4; i++)
+ sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
+
+ p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
+ p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
+
+ sin->sin_family = AF_INET; /* always */
+ memcpy((char *)&sin->sin_port, (char *)&p_bytes, 2);
+
+ return (0);
+}
+
+/*
+ * free_eps()
+ *
+ * Free the strings that were strduped into the eps structure.
+ */
+static void
+free_eps(eps, num)
+ endpoint eps[];
+ int num;
+{
+ int i;
+
+ for (i = 0; i < num; i++) {
+ free(eps[i].uaddr);
+ free(eps[i].proto);
+ free(eps[i].family);
+ }
+ return;
+}
+
+/*
+ * get_server()
+ *
+ * This function constructs a nis_server structure description for the
+ * indicated hostname.
+ *
+ * NOTE: There is a chance we may end up recursing here due to the
+ * fact that gethostbyname() could do an NIS search. Ideally, the
+ * NIS+ server will call __rpc_get_time_offset() with the nis_server
+ * structure already populated.
+ */
+static nis_server *
+get_server(sin, host, srv, eps, maxep)
+ struct sockaddr_in *sin;
+ char *host; /* name of the time host */
+ nis_server *srv; /* nis_server struct to use. */
+ endpoint eps[]; /* array of endpoints */
+ int maxep; /* max array size */
+{
+ char hname[256];
+ int num_ep = 0, i;
+ struct hostent *he;
+ struct hostent dummy;
+ char *ptr[2];
+
+ if (host == NULL && sin == NULL)
+ return (NULL);
+
+ if (sin == NULL) {
+ he = gethostbyname(host);
+ if (he == NULL)
+ return(NULL);
+ } else {
+ he = &dummy;
+ ptr[0] = (char *)&sin->sin_addr.s_addr;
+ ptr[1] = NULL;
+ dummy.h_addr_list = ptr;
+ }
+
+ /*
+ * This is lame. We go around once for TCP, then again
+ * for UDP.
+ */
+ for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
+ i++, num_ep++) {
+ struct in_addr *a;
+
+ a = (struct in_addr *)he->h_addr_list[i];
+ snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
+ eps[num_ep].uaddr = strdup(hname);
+ eps[num_ep].family = strdup("inet");
+ eps[num_ep].proto = strdup("tcp");
+ }
+
+ for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
+ i++, num_ep++) {
+ struct in_addr *a;
+
+ a = (struct in_addr *)he->h_addr_list[i];
+ snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
+ eps[num_ep].uaddr = strdup(hname);
+ eps[num_ep].family = strdup("inet");
+ eps[num_ep].proto = strdup("udp");
+ }
+
+ srv->name = (nis_name) host;
+ srv->ep.ep_len = num_ep;
+ srv->ep.ep_val = eps;
+ srv->key_type = NIS_PK_NONE;
+ srv->pkey.n_bytes = NULL;
+ srv->pkey.n_len = 0;
+ return (srv);
+}
+
+/*
+ * __rpc_get_time_offset()
+ *
+ * This function uses a nis_server structure to contact the a remote
+ * machine (as named in that structure) and returns the offset in time
+ * between that machine and this one. This offset is returned in seconds
+ * and may be positive or negative.
+ *
+ * The first time through, a lot of fiddling is done with the netconfig
+ * stuff to find a suitable transport. The function is very aggressive
+ * about choosing UDP or at worst TCP if it can. This is because
+ * those transports support both the RCPBIND call and the internet
+ * time service.
+ *
+ * Once through, *uaddr is set to the universal address of
+ * the machine and *netid is set to the local netid for the transport
+ * that uaddr goes with. On the second call, the netconfig stuff
+ * is skipped and the uaddr/netid pair are used to fetch the netconfig
+ * structure and to then contact the machine for the time.
+ *
+ * td = "server" - "client"
+ */
+int
+__rpc_get_time_offset(td, srv, thost, uaddr, netid)
+ struct timeval *td; /* Time difference */
+ nis_server *srv; /* NIS Server description */
+ char *thost; /* if no server, this is the timehost */
+ char **uaddr; /* known universal address */
+ struct sockaddr_in *netid; /* known network identifier */
+{
+ CLIENT *clnt; /* Client handle */
+ endpoint *ep, /* useful endpoints */
+ *useep = NULL; /* endpoint of xp */
+ char *useua = NULL; /* uaddr of selected xp */
+ int epl, i; /* counters */
+ enum clnt_stat status; /* result of clnt_call */
+ u_long thetime, delta;
+ int needfree = 0;
+ struct timeval tv;
+ int time_valid;
+ int udp_ep = -1, tcp_ep = -1;
+ int a1, a2, a3, a4;
+ char ut[64], ipuaddr[64];
+ endpoint teps[32];
+ nis_server tsrv;
+ void (*oldsig)() = NULL; /* old alarm handler */
+ struct sockaddr_in sin;
+ int s = RPC_ANYSOCK;
+ socklen_t len;
+ int type = 0;
+
+ td->tv_sec = 0;
+ td->tv_usec = 0;
+
+ /*
+ * First check to see if we need to find and address for this
+ * server.
+ */
+ if (*uaddr == NULL) {
+ if ((srv != NULL) && (thost != NULL)) {
+ msg("both timehost and srv pointer used!");
+ return (0);
+ }
+ if (! srv) {
+ srv = get_server(netid, thost, &tsrv, teps, 32);
+ if (srv == NULL) {
+ msg("unable to contruct server data.");
+ return (0);
+ }
+ needfree = 1; /* need to free data in endpoints */
+ }
+
+ ep = srv->ep.ep_val;
+ epl = srv->ep.ep_len;
+
+ /* Identify the TCP and UDP endpoints */
+ for (i = 0;
+ (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
+ if (strcasecmp(ep[i].proto, "udp") == 0)
+ udp_ep = i;
+ if (strcasecmp(ep[i].proto, "tcp") == 0)
+ tcp_ep = i;
+ }
+
+ /* Check to see if it is UDP or TCP */
+ if (tcp_ep > -1) {
+ useep = &ep[tcp_ep];
+ useua = ep[tcp_ep].uaddr;
+ type = SOCK_STREAM;
+ } else if (udp_ep > -1) {
+ useep = &ep[udp_ep];
+ useua = ep[udp_ep].uaddr;
+ type = SOCK_DGRAM;
+ }
+
+ if (useep == NULL) {
+ msg("no acceptable transport endpoints.");
+ if (needfree)
+ free_eps(teps, tsrv.ep.ep_len);
+ return (0);
+ }
+ }
+
+ /*
+ * Create a sockaddr from the uaddr.
+ */
+ if (*uaddr != NULL)
+ useua = *uaddr;
+
+ /* Fixup test for NIS+ */
+ sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
+ sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
+ useua = &ipuaddr[0];
+
+ memset(&sin, 0, sizeof(sin));
+ if (uaddr_to_sockaddr(useua, &sin)) {
+ msg("unable to translate uaddr to sockaddr.");
+ if (needfree)
+ free_eps(teps, tsrv.ep.ep_len);
+ return (0);
+ }
+
+ /*
+ * Create the client handle to rpcbind. Note we always try
+ * version 3 since that is the earliest version that supports
+ * the RPCB_GETTIME call. Also it is the version that comes
+ * standard with SVR4. Since most everyone supports TCP/IP
+ * we could consider trying the rtime call first.
+ */
+ clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
+ if (clnt == NULL) {
+ msg("unable to create client handle to rpcbind.");
+ if (needfree)
+ free_eps(teps, tsrv.ep.ep_len);
+ return (0);
+ }
+
+ tv.tv_sec = 5;
+ tv.tv_usec = 0;
+ time_valid = 0;
+ status = clnt_call(clnt, RPCBPROC_GETTIME, (xdrproc_t)xdr_void, NULL,
+ (xdrproc_t)xdr_u_long, &thetime, tv);
+ /*
+ * The only error we check for is anything but success. In
+ * fact we could have seen PROGMISMATCH if talking to a 4.1
+ * machine (pmap v2) or TIMEDOUT if the net was busy.
+ */
+ if (status == RPC_SUCCESS)
+ time_valid = 1;
+ else {
+ int save;
+
+ /* Blow away possible stale CLNT handle. */
+ if (clnt != NULL) {
+ clnt_destroy(clnt);
+ clnt = NULL;
+ }
+
+ /*
+ * Convert PMAP address into timeservice address
+ * We take advantage of the fact that we "know" what
+ * the universal address looks like for inet transports.
+ *
+ * We also know that the internet timeservice is always
+ * listening on port 37.
+ */
+ sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
+ sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
+
+ if (uaddr_to_sockaddr(ut, &sin)) {
+ msg("cannot convert timeservice uaddr to sockaddr.");
+ goto error;
+ }
+
+ s = socket(AF_INET, type, 0);
+ if (s == -1) {
+ msg("unable to open fd to network.");
+ goto error;
+ }
+
+ /*
+ * Now depending on whether or not we're talking to
+ * UDP we set a timeout or not.
+ */
+ if (type == SOCK_DGRAM) {
+ struct timeval timeout = { 20, 0 };
+ struct sockaddr_in from;
+ fd_set readfds;
+ int res;
+
+ if (sendto(s, &thetime, sizeof(thetime), 0,
+ (struct sockaddr *)&sin, sizeof(sin)) == -1) {
+ msg("udp : sendto failed.");
+ goto error;
+ }
+ do {
+ FD_ZERO(&readfds);
+ FD_SET(s, &readfds);
+ res = select(_rpc_dtablesize(), &readfds,
+ (fd_set *)NULL, (fd_set *)NULL, &timeout);
+ } while (res < 0 && errno == EINTR);
+ if (res <= 0)
+ goto error;
+ len = sizeof(from);
+ res = recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
+ (struct sockaddr *)&from, &len);
+ if (res == -1) {
+ msg("recvfrom failed on udp transport.");
+ goto error;
+ }
+ time_valid = 1;
+ } else {
+ int res;
+
+ oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
+ saw_alarm = 0; /* global tracking the alarm */
+ alarm(20); /* only wait 20 seconds */
+ res = connect(s, (struct sockaddr *)&sin, sizeof(sin));
+ if (res == -1) {
+ msg("failed to connect to tcp endpoint.");
+ goto error;
+ }
+ if (saw_alarm) {
+ msg("alarm caught it, must be unreachable.");
+ goto error;
+ }
+ res = read(s, (char *)&thetime, sizeof(thetime));
+ if (res != sizeof(thetime)) {
+ if (saw_alarm)
+ msg("timed out TCP call.");
+ else
+ msg("wrong size of results returned");
+
+ goto error;
+ }
+ time_valid = 1;
+ }
+ save = errno;
+ (void)close(s);
+ errno = save;
+ s = RPC_ANYSOCK;
+
+ if (time_valid) {
+ thetime = ntohl(thetime);
+ thetime = thetime - TOFFSET; /* adjust to UNIX time */
+ } else
+ thetime = 0;
+ }
+
+ gettimeofday(&tv, 0);
+
+error:
+ /*
+ * clean up our allocated data structures.
+ */
+
+ if (s != RPC_ANYSOCK)
+ (void)close(s);
+
+ if (clnt != NULL)
+ clnt_destroy(clnt);
+
+ alarm(0); /* reset that alarm if its outstanding */
+ if (oldsig) {
+ signal(SIGALRM, oldsig);
+ }
+
+ /*
+ * note, don't free uaddr strings until after we've made a
+ * copy of them.
+ */
+ if (time_valid) {
+ if (*uaddr == NULL)
+ *uaddr = strdup(useua);
+
+ /* Round to the nearest second */
+ tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
+ delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
+ tv.tv_sec - thetime;
+ td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
+ td->tv_usec = 0;
+ } else {
+ msg("unable to get the server's time.");
+ }
+
+ if (needfree)
+ free_eps(teps, tsrv.ep.ep_len);
+
+ return (time_valid);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 23:48:12 +0000