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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 05:45:02 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 05:45:02 +0000 |
commit | 68a560641f7a38c184fd3346dd8008b86e12d77a (patch) | |
tree | d927b2a890d51e5d9e037c03042fb6fabd689cc0 /src/auth_time.c | |
parent | Initial commit. (diff) | |
download | libtirpc-cee9a4dfe20cd898463d1bead96aa1f5dcde6ef5.tar.xz libtirpc-cee9a4dfe20cd898463d1bead96aa1f5dcde6ef5.zip |
Adding upstream version 1.3.4+ds.upstream/1.3.4+dsupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/auth_time.c')
-rw-r--r-- | src/auth_time.c | 495 |
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); +} |