freebsd-dev/usr.sbin/ypbind/ypbind.c
Gleb Smirnoff 5838507bd7 Protect NIS client with madvise(2) since this daemon is required
for succesful authentication of users.
2011-10-24 14:35:31 +00:00

1006 lines
25 KiB
C

/*
* Copyright (c) 1992/3 Theo de Raadt <deraadt@fsa.ca>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#include <rpc/pmap_rmt.h>
#include <rpc/rpc_com.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "yp_ping.h"
#ifndef BINDINGDIR
#define BINDINGDIR "/var/yp/binding"
#endif
#ifndef YPBINDLOCK
#define YPBINDLOCK "/var/run/ypbind.lock"
#endif
struct _dom_binding {
struct _dom_binding *dom_pnext;
char dom_domain[YPMAXDOMAIN + 1];
struct sockaddr_in dom_server_addr;
long int dom_vers;
int dom_lockfd;
int dom_alive;
int dom_broadcast_pid;
int dom_pipe_fds[2];
int dom_default;
};
#define READFD ypdb->dom_pipe_fds[0]
#define WRITEFD ypdb->dom_pipe_fds[1]
#define BROADFD broad_domain->dom_pipe_fds[1]
extern bool_t xdr_domainname(), xdr_ypbind_resp();
extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
extern bool_t xdr_ypbind_setdom();
void checkwork(void);
void *ypbindproc_null_2_yp(SVCXPRT *, void *, CLIENT *);
void *ypbindproc_setdom_2_yp(SVCXPRT *, struct ypbind_setdom *, CLIENT *);
void rpc_received(char *, struct sockaddr_in *, int);
void broadcast(struct _dom_binding *);
int ping(struct _dom_binding *);
int tell_parent(char *, struct sockaddr_in *);
void handle_children(struct _dom_binding *);
void reaper(int);
void terminate(int);
void yp_restricted_mode(char *);
int verify(struct in_addr);
char *domain_name;
struct _dom_binding *ypbindlist;
static struct _dom_binding *broad_domain;
#define YPSET_NO 0
#define YPSET_LOCAL 1
#define YPSET_ALL 2
int ypsetmode = YPSET_NO;
int ypsecuremode = 0;
int ppid;
#define NOT_RESPONDING_HYSTERESIS 10
static int not_responding_count = 0;
/*
* Special restricted mode variables: when in restricted mode, only the
* specified restricted_domain will be bound, and only the servers listed
* in restricted_addrs will be used for binding.
*/
#define RESTRICTED_SERVERS 10
int yp_restricted = 0;
int yp_manycast = 0;
struct in_addr restricted_addrs[RESTRICTED_SERVERS];
/* No more than MAX_CHILDREN child broadcasters at a time. */
#ifndef MAX_CHILDREN
#define MAX_CHILDREN 5
#endif
/* No more than MAX_DOMAINS simultaneous domains */
#ifndef MAX_DOMAINS
#define MAX_DOMAINS 200
#endif
/* RPC timeout value */
#ifndef FAIL_THRESHOLD
#define FAIL_THRESHOLD 20
#endif
/* Number of times to fish for a response froma particular set of hosts */
#ifndef MAX_RETRIES
#define MAX_RETRIES 30
#endif
int retries = 0;
int children = 0;
int domains = 0;
int yplockfd;
fd_set fdsr;
SVCXPRT *udptransp, *tcptransp;
void *
ypbindproc_null_2_yp(SVCXPRT *transp, void *argp, CLIENT *clnt)
{
static char res;
bzero(&res, sizeof(res));
return &res;
}
struct ypbind_resp *
ypbindproc_domain_2_yp(SVCXPRT *transp, domainname *argp, CLIENT *clnt)
{
static struct ypbind_resp res;
struct _dom_binding *ypdb;
char path[MAXPATHLEN];
bzero(&res, sizeof res);
res.ypbind_status = YPBIND_FAIL_VAL;
res.ypbind_resp_u.ypbind_error = YPBIND_ERR_NOSERV;
if (strchr(*argp, '/')) {
syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
rejecting.", *argp);
return(&res);
}
for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
if (strcmp(ypdb->dom_domain, *argp) == 0)
break;
}
if (ypdb == NULL) {
if (yp_restricted) {
syslog(LOG_NOTICE, "Running in restricted mode -- request to bind domain \"%s\" rejected.\n", *argp);
return (&res);
}
if (domains >= MAX_DOMAINS) {
syslog(LOG_WARNING, "domain limit (%d) exceeded",
MAX_DOMAINS);
res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
return (&res);
}
ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
if (ypdb == NULL) {
syslog(LOG_WARNING, "malloc: %m");
res.ypbind_resp_u.ypbind_error = YPBIND_ERR_RESC;
return (&res);
}
bzero(ypdb, sizeof *ypdb);
strncpy(ypdb->dom_domain, *argp, sizeof ypdb->dom_domain);
ypdb->dom_vers = YPVERS;
ypdb->dom_alive = 0;
ypdb->dom_default = 0;
ypdb->dom_lockfd = -1;
sprintf(path, "%s/%s.%ld", BINDINGDIR,
ypdb->dom_domain, ypdb->dom_vers);
unlink(path);
ypdb->dom_pnext = ypbindlist;
ypbindlist = ypdb;
domains++;
}
if (ping(ypdb)) {
return (&res);
}
res.ypbind_status = YPBIND_SUCC_VAL;
res.ypbind_resp_u.ypbind_error = 0; /* Success */
*(u_int32_t *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr =
ypdb->dom_server_addr.sin_addr.s_addr;
*(u_short *)&res.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port =
ypdb->dom_server_addr.sin_port;
/*printf("domain %s at %s/%d\n", ypdb->dom_domain,
inet_ntoa(ypdb->dom_server_addr.sin_addr),
ntohs(ypdb->dom_server_addr.sin_port));*/
return (&res);
}
void *
ypbindproc_setdom_2_yp(SVCXPRT *transp, ypbind_setdom *argp, CLIENT *clnt)
{
struct sockaddr_in *fromsin, bindsin;
static char *result = NULL;
if (strchr(argp->ypsetdom_domain, '/')) {
syslog(LOG_WARNING, "Domain name '%s' has embedded slash -- \
rejecting.", argp->ypsetdom_domain);
return(NULL);
}
fromsin = svc_getcaller(transp);
switch (ypsetmode) {
case YPSET_LOCAL:
if (fromsin->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) {
svcerr_noprog(transp);
return(NULL);
}
break;
case YPSET_ALL:
break;
case YPSET_NO:
default:
svcerr_noprog(transp);
return(NULL);
}
if (ntohs(fromsin->sin_port) >= IPPORT_RESERVED) {
svcerr_noprog(transp);
return(NULL);
}
if (argp->ypsetdom_vers != YPVERS) {
svcerr_noprog(transp);
return(NULL);
}
bzero(&bindsin, sizeof bindsin);
bindsin.sin_family = AF_INET;
bindsin.sin_addr.s_addr = *(u_int32_t *)argp->ypsetdom_binding.ypbind_binding_addr;
bindsin.sin_port = *(u_short *)argp->ypsetdom_binding.ypbind_binding_port;
rpc_received(argp->ypsetdom_domain, &bindsin, 1);
return((void *) &result);
}
void
ypbindprog_2(struct svc_req *rqstp, register SVCXPRT *transp)
{
union {
domainname ypbindproc_domain_2_arg;
struct ypbind_setdom ypbindproc_setdom_2_arg;
} argument;
struct authunix_parms *creds;
char *result;
bool_t (*xdr_argument)(), (*xdr_result)();
char *(*local)();
switch (rqstp->rq_proc) {
case YPBINDPROC_NULL:
xdr_argument = xdr_void;
xdr_result = xdr_void;
local = (char *(*)()) ypbindproc_null_2_yp;
break;
case YPBINDPROC_DOMAIN:
xdr_argument = xdr_domainname;
xdr_result = xdr_ypbind_resp;
local = (char *(*)()) ypbindproc_domain_2_yp;
break;
case YPBINDPROC_SETDOM:
switch (rqstp->rq_cred.oa_flavor) {
case AUTH_UNIX:
creds = (struct authunix_parms *)rqstp->rq_clntcred;
if (creds->aup_uid != 0) {
svcerr_auth(transp, AUTH_BADCRED);
return;
}
break;
default:
svcerr_auth(transp, AUTH_TOOWEAK);
return;
}
xdr_argument = xdr_ypbind_setdom;
xdr_result = xdr_void;
local = (char *(*)()) ypbindproc_setdom_2_yp;
break;
default:
svcerr_noproc(transp);
return;
}
bzero(&argument, sizeof(argument));
if (!svc_getargs(transp, (xdrproc_t)xdr_argument, &argument)) {
svcerr_decode(transp);
return;
}
result = (*local)(transp, &argument, rqstp);
if (result != NULL &&
!svc_sendreply(transp, (xdrproc_t)xdr_result, result)) {
svcerr_systemerr(transp);
}
return;
}
/* Jack the reaper */
void
reaper(int sig)
{
int st;
while (wait3(&st, WNOHANG, NULL) > 0)
children--;
}
void
terminate(int sig)
{
struct _dom_binding *ypdb;
char path[MAXPATHLEN];
if (ppid != getpid())
exit(0);
for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
close(ypdb->dom_lockfd);
if (ypdb->dom_broadcast_pid)
kill(ypdb->dom_broadcast_pid, SIGINT);
sprintf(path, "%s/%s.%ld", BINDINGDIR,
ypdb->dom_domain, ypdb->dom_vers);
unlink(path);
}
close(yplockfd);
unlink(YPBINDLOCK);
pmap_unset(YPBINDPROG, YPBINDVERS);
exit(0);
}
int
main(int argc, char *argv[])
{
struct timeval tv;
int i;
DIR *dird;
struct dirent *dirp;
struct _dom_binding *ypdb, *next;
/* Check that another ypbind isn't already running. */
if ((yplockfd = (open(YPBINDLOCK, O_RDONLY|O_CREAT, 0444))) == -1)
err(1, "%s", YPBINDLOCK);
if (flock(yplockfd, LOCK_EX|LOCK_NB) == -1 && errno == EWOULDBLOCK)
errx(1, "another ypbind is already running. Aborting");
/* XXX domainname will be overriden if we use restricted mode */
yp_get_default_domain(&domain_name);
if (domain_name[0] == '\0')
errx(1, "domainname not set. Aborting");
for (i = 1; i<argc; i++) {
if (strcmp("-ypset", argv[i]) == 0)
ypsetmode = YPSET_ALL;
else if (strcmp("-ypsetme", argv[i]) == 0)
ypsetmode = YPSET_LOCAL;
else if (strcmp("-s", argv[i]) == 0)
ypsecuremode++;
else if (strcmp("-S", argv[i]) == 0 && argc > i)
yp_restricted_mode(argv[++i]);
else if (strcmp("-m", argv[i]) == 0)
yp_manycast++;
else
errx(1, "unknown option: %s", argv[i]);
}
/* blow away everything in BINDINGDIR (if it exists) */
if ((dird = opendir(BINDINGDIR)) != NULL) {
char path[MAXPATHLEN];
while ((dirp = readdir(dird)) != NULL)
if (strcmp(dirp->d_name, ".") &&
strcmp(dirp->d_name, "..")) {
sprintf(path,"%s/%s",BINDINGDIR,dirp->d_name);
unlink(path);
}
closedir(dird);
}
#ifdef DAEMON
if (daemon(0,0))
err(1, "fork");
#endif
pmap_unset(YPBINDPROG, YPBINDVERS);
udptransp = svcudp_create(RPC_ANYSOCK);
if (udptransp == NULL)
errx(1, "cannot create udp service");
if (!svc_register(udptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
IPPROTO_UDP))
errx(1, "unable to register (YPBINDPROG, YPBINDVERS, udp)");
tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0);
if (tcptransp == NULL)
errx(1, "cannot create tcp service");
if (!svc_register(tcptransp, YPBINDPROG, YPBINDVERS, ypbindprog_2,
IPPROTO_TCP))
errx(1, "unable to register (YPBINDPROG, YPBINDVERS, tcp)");
/* build initial domain binding, make it "unsuccessful" */
ypbindlist = (struct _dom_binding *)malloc(sizeof *ypbindlist);
if (ypbindlist == NULL)
errx(1, "malloc");
bzero(ypbindlist, sizeof *ypbindlist);
strncpy(ypbindlist->dom_domain, domain_name, sizeof ypbindlist->dom_domain);
ypbindlist->dom_vers = YPVERS;
ypbindlist->dom_alive = 0;
ypbindlist->dom_lockfd = -1;
ypbindlist->dom_default = 1;
domains++;
signal(SIGCHLD, reaper);
signal(SIGTERM, terminate);
ppid = getpid(); /* Remember who we are. */
openlog(argv[0], LOG_PID, LOG_DAEMON);
if (madvise(NULL, 0, MADV_PROTECT) != 0)
syslog(LOG_WARNING, "madvise(): %m");
/* Kick off the default domain */
broadcast(ypbindlist);
while (1) {
fdsr = svc_fdset;
tv.tv_sec = 60;
tv.tv_usec = 0;
switch (select(_rpc_dtablesize(), &fdsr, NULL, NULL, &tv)) {
case 0:
checkwork();
break;
case -1:
if (errno != EINTR)
syslog(LOG_WARNING, "select: %m");
break;
default:
for (ypdb = ypbindlist; ypdb; ypdb = next) {
next = ypdb->dom_pnext;
if (READFD > 0 && FD_ISSET(READFD, &fdsr)) {
handle_children(ypdb);
if (children == (MAX_CHILDREN - 1))
checkwork();
}
}
svc_getreqset(&fdsr);
break;
}
}
/* NOTREACHED */
exit(1);
}
void
checkwork(void)
{
struct _dom_binding *ypdb;
for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext)
ping(ypdb);
}
/* The clnt_broadcast() callback mechanism sucks. */
/*
* Receive results from broadcaster. Don't worry about passing
* bogus info to rpc_received() -- it can handle it. Note that we
* must be sure to invalidate the dom_pipe_fds descriptors here:
* since descriptors can be re-used, we have to make sure we
* don't mistake one of the RPC descriptors for one of the pipes.
* What's weird is that forgetting to invalidate the pipe descriptors
* doesn't always result in an error (otherwise I would have caught
* the mistake much sooner), even though logically it should.
*/
void
handle_children(struct _dom_binding *ypdb)
{
char buf[YPMAXDOMAIN + 1];
struct sockaddr_in addr;
int d = 0, a = 0;
struct _dom_binding *y, *prev = NULL;
char path[MAXPATHLEN];
if ((d = read(READFD, &buf, sizeof(buf))) <= 0)
syslog(LOG_WARNING, "could not read from child: %m");
if ((a = read(READFD, &addr, sizeof(struct sockaddr_in))) < 0)
syslog(LOG_WARNING, "could not read from child: %m");
close(READFD);
FD_CLR(READFD, &fdsr);
FD_CLR(READFD, &svc_fdset);
READFD = WRITEFD = -1;
if (d > 0 && a > 0)
rpc_received(buf, &addr, 0);
else {
for (y = ypbindlist; y; y = y->dom_pnext) {
if (y == ypdb)
break;
prev = y;
}
switch (ypdb->dom_default) {
case 0:
if (prev == NULL)
ypbindlist = y->dom_pnext;
else
prev->dom_pnext = y->dom_pnext;
sprintf(path, "%s/%s.%ld", BINDINGDIR,
ypdb->dom_domain, YPVERS);
close(ypdb->dom_lockfd);
unlink(path);
free(ypdb);
domains--;
return;
case 1:
ypdb->dom_broadcast_pid = 0;
ypdb->dom_alive = 0;
broadcast(ypdb);
return;
default:
break;
}
}
return;
}
/*
* Send our dying words back to our parent before we perish.
*/
int
tell_parent(char *dom, struct sockaddr_in *addr)
{
char buf[YPMAXDOMAIN + 1];
struct timeval timeout;
fd_set fds;
timeout.tv_sec = 5;
timeout.tv_usec = 0;
sprintf(buf, "%s", broad_domain->dom_domain);
if (write(BROADFD, &buf, sizeof(buf)) < 0)
return(1);
/*
* Stay in sync with parent: wait for it to read our first
* message before sending the second.
*/
FD_ZERO(&fds);
FD_SET(BROADFD, &fds);
if (select(FD_SETSIZE, NULL, &fds, NULL, &timeout) == -1)
return(1);
if (FD_ISSET(BROADFD, &fds)) {
if (write(BROADFD, addr, sizeof(struct sockaddr_in)) < 0)
return(1);
} else {
return(1);
}
close(BROADFD);
return (0);
}
bool_t broadcast_result(out, addr)
bool_t *out;
struct sockaddr_in *addr;
{
if (retries >= MAX_RETRIES) {
bzero(addr, sizeof(struct sockaddr_in));
if (tell_parent(broad_domain->dom_domain, addr))
syslog(LOG_WARNING, "lost connection to parent");
return (TRUE);
}
if (yp_restricted && verify(addr->sin_addr)) {
retries++;
syslog(LOG_NOTICE, "NIS server at %s not in restricted mode access list -- rejecting.\n",inet_ntoa(addr->sin_addr));
return (FALSE);
} else {
if (tell_parent(broad_domain->dom_domain, addr))
syslog(LOG_WARNING, "lost connection to parent");
return (TRUE);
}
}
/*
* The right way to send RPC broadcasts.
* Use the clnt_broadcast() RPC service. Unfortunately, clnt_broadcast()
* blocks while waiting for replies, so we have to fork off separate
* broadcaster processes that do the waiting and then transmit their
* results back to the parent for processing. We also have to remember
* to save the name of the domain we're trying to bind in a global
* variable since clnt_broadcast() provides no way to pass things to
* the 'eachresult' callback function.
*/
void
broadcast(struct _dom_binding *ypdb)
{
bool_t out = FALSE;
enum clnt_stat stat;
if (children >= MAX_CHILDREN || ypdb->dom_broadcast_pid)
return;
if (pipe(ypdb->dom_pipe_fds) < 0) {
syslog(LOG_WARNING, "pipe: %m");
return;
}
if (ypdb->dom_vers == -1 && (long)ypdb->dom_server_addr.sin_addr.s_addr) {
if (not_responding_count++ >= NOT_RESPONDING_HYSTERESIS) {
not_responding_count = NOT_RESPONDING_HYSTERESIS;
syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" not responding",
inet_ntoa(ypdb->dom_server_addr.sin_addr), ypdb->dom_domain);
}
}
broad_domain = ypdb;
flock(ypdb->dom_lockfd, LOCK_UN);
switch ((ypdb->dom_broadcast_pid = fork())) {
case 0:
close(READFD);
signal(SIGCHLD, SIG_DFL);
signal(SIGTERM, SIG_DFL);
break;
case -1:
syslog(LOG_WARNING, "fork: %m");
close(READFD);
close(WRITEFD);
return;
default:
close(WRITEFD);
FD_SET(READFD, &svc_fdset);
children++;
return;
}
/* Release all locks before doing anything else. */
while (ypbindlist) {
close(ypbindlist->dom_lockfd);
ypbindlist = ypbindlist->dom_pnext;
}
close(yplockfd);
/*
* Special 'many-cast' behavior. If we're in restricted mode,
* we have a list of possible server addresses to try. What
* we can do is transmit to each ypserv's YPPROC_DOMAIN_NONACK
* procedure and time the replies. Whoever replies fastest
* gets to be our server. Note that this is not a broadcast
* operation: we transmit uni-cast datagrams only.
*/
if (yp_restricted && yp_manycast) {
short port;
int i;
struct sockaddr_in sin;
i = __yp_ping(restricted_addrs, yp_restricted,
ypdb->dom_domain, &port);
if (i == -1) {
bzero(&ypdb->dom_server_addr,
sizeof(struct sockaddr_in));
if (tell_parent(ypdb->dom_domain,
&ypdb->dom_server_addr))
syslog(LOG_WARNING, "lost connection to parent");
} else {
bzero(&sin, sizeof(struct sockaddr_in));
bcopy(&restricted_addrs[i],
&sin.sin_addr, sizeof(struct in_addr));
sin.sin_family = AF_INET;
sin.sin_port = port;
if (tell_parent(broad_domain->dom_domain, &sin))
syslog(LOG_WARNING,
"lost connection to parent");
}
_exit(0);
}
retries = 0;
{
char *ptr;
ptr = ypdb->dom_domain;
stat = clnt_broadcast(YPPROG, YPVERS, YPPROC_DOMAIN_NONACK,
(xdrproc_t)xdr_domainname, &ptr,
(xdrproc_t)xdr_bool, &out,
(resultproc_t)broadcast_result);
}
if (stat != RPC_SUCCESS) {
bzero(&ypdb->dom_server_addr,
sizeof(struct sockaddr_in));
if (tell_parent(ypdb->dom_domain, &ypdb->dom_server_addr))
syslog(LOG_WARNING, "lost connection to parent");
}
_exit(0);
}
/*
* The right way to check if a server is alive.
* Attempt to get a client handle pointing to the server and send a
* YPPROC_DOMAIN. If we can't get a handle or we get a reply of FALSE,
* we invalidate this binding entry and send out a broadcast to try to
* establish a new binding. Note that we treat non-default domains
* specially: once bound, we keep tabs on our server, but if it
* goes away and fails to respond after one round of broadcasting, we
* abandon it until a client specifically references it again. We make
* every effort to keep our default domain bound, however, since we
* need it to keep the system on its feet.
*/
int
ping(struct _dom_binding *ypdb)
{
bool_t out;
struct timeval interval, timeout;
enum clnt_stat stat;
int rpcsock = RPC_ANYSOCK;
CLIENT *client_handle;
interval.tv_sec = FAIL_THRESHOLD;
interval.tv_usec = 0;
timeout.tv_sec = FAIL_THRESHOLD;
timeout.tv_usec = 0;
if (ypdb->dom_broadcast_pid)
return(1);
if ((client_handle = clntudp_bufcreate(&ypdb->dom_server_addr,
YPPROG, YPVERS, interval, &rpcsock, RPCSMALLMSGSIZE,
RPCSMALLMSGSIZE)) == (CLIENT *)NULL) {
/* Can't get a handle: we're dead. */
ypdb->dom_alive = 0;
ypdb->dom_vers = -1;
broadcast(ypdb);
return(1);
}
{
char *ptr;
ptr = ypdb->dom_domain;
stat = clnt_call(client_handle, YPPROC_DOMAIN,
(xdrproc_t)xdr_domainname, &ptr,
(xdrproc_t)xdr_bool, &out, timeout);
if (stat != RPC_SUCCESS || out == FALSE) {
ypdb->dom_alive = 0;
ypdb->dom_vers = -1;
clnt_destroy(client_handle);
broadcast(ypdb);
return(1);
}
}
clnt_destroy(client_handle);
return(0);
}
void
rpc_received(char *dom, struct sockaddr_in *raddrp, int force)
{
struct _dom_binding *ypdb, *prev = NULL;
struct iovec iov[2];
struct ypbind_resp ybr;
char path[MAXPATHLEN];
int fd;
/*printf("returned from %s/%d about %s\n", inet_ntoa(raddrp->sin_addr),
ntohs(raddrp->sin_port), dom);*/
if (dom == NULL)
return;
for (ypdb = ypbindlist; ypdb; ypdb = ypdb->dom_pnext) {
if (strcmp(ypdb->dom_domain, dom) == 0)
break;
prev = ypdb;
}
if (ypdb && force) {
if (ypdb->dom_broadcast_pid) {
kill(ypdb->dom_broadcast_pid, SIGINT);
close(READFD);
FD_CLR(READFD, &fdsr);
FD_CLR(READFD, &svc_fdset);
READFD = WRITEFD = -1;
}
}
/* if in secure mode, check originating port number */
if ((ypsecuremode && (ntohs(raddrp->sin_port) >= IPPORT_RESERVED))) {
syslog(LOG_WARNING, "Rejected NIS server on [%s/%d] for domain %s.",
inet_ntoa(raddrp->sin_addr), ntohs(raddrp->sin_port),
dom);
if (ypdb != NULL) {
ypdb->dom_broadcast_pid = 0;
ypdb->dom_alive = 0;
}
return;
}
if (raddrp->sin_addr.s_addr == (long)0) {
switch (ypdb->dom_default) {
case 0:
if (prev == NULL)
ypbindlist = ypdb->dom_pnext;
else
prev->dom_pnext = ypdb->dom_pnext;
sprintf(path, "%s/%s.%ld", BINDINGDIR,
ypdb->dom_domain, YPVERS);
close(ypdb->dom_lockfd);
unlink(path);
free(ypdb);
domains--;
return;
case 1:
ypdb->dom_broadcast_pid = 0;
ypdb->dom_alive = 0;
broadcast(ypdb);
return;
default:
break;
}
}
if (ypdb == NULL) {
if (force == 0)
return;
ypdb = (struct _dom_binding *)malloc(sizeof *ypdb);
if (ypdb == NULL) {
syslog(LOG_WARNING, "malloc: %m");
return;
}
bzero(ypdb, sizeof *ypdb);
strncpy(ypdb->dom_domain, dom, sizeof ypdb->dom_domain);
ypdb->dom_lockfd = -1;
ypdb->dom_default = 0;
ypdb->dom_pnext = ypbindlist;
ypbindlist = ypdb;
}
/* We've recovered from a crash: inform the world. */
if (ypdb->dom_vers == -1 && ypdb->dom_server_addr.sin_addr.s_addr) {
if (not_responding_count >= NOT_RESPONDING_HYSTERESIS) {
not_responding_count = 0;
syslog(LOG_WARNING, "NIS server [%s] for domain \"%s\" OK",
inet_ntoa(raddrp->sin_addr), ypdb->dom_domain);
}
}
bcopy(raddrp, &ypdb->dom_server_addr,
sizeof ypdb->dom_server_addr);
ypdb->dom_vers = YPVERS;
ypdb->dom_alive = 1;
ypdb->dom_broadcast_pid = 0;
if (ypdb->dom_lockfd != -1)
close(ypdb->dom_lockfd);
sprintf(path, "%s/%s.%ld", BINDINGDIR,
ypdb->dom_domain, ypdb->dom_vers);
#ifdef O_SHLOCK
if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1) {
(void)mkdir(BINDINGDIR, 0755);
if ((fd = open(path, O_CREAT|O_SHLOCK|O_RDWR|O_TRUNC, 0644)) == -1)
return;
}
#else
if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1) {
(void)mkdir(BINDINGDIR, 0755);
if ((fd = open(path, O_CREAT|O_RDWR|O_TRUNC, 0644)) == -1)
return;
}
flock(fd, LOCK_SH);
#endif
/*
* ok, if BINDINGDIR exists, and we can create the binding file,
* then write to it..
*/
ypdb->dom_lockfd = fd;
iov[0].iov_base = (char *)&(udptransp->xp_port);
iov[0].iov_len = sizeof udptransp->xp_port;
iov[1].iov_base = (char *)&ybr;
iov[1].iov_len = sizeof ybr;
bzero(&ybr, sizeof ybr);
ybr.ypbind_status = YPBIND_SUCC_VAL;
*(u_int32_t *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr = raddrp->sin_addr.s_addr;
*(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port = raddrp->sin_port;
if (writev(ypdb->dom_lockfd, iov, 2) != iov[0].iov_len + iov[1].iov_len) {
syslog(LOG_WARNING, "write: %m");
close(ypdb->dom_lockfd);
ypdb->dom_lockfd = -1;
return;
}
}
/*
* Check address against list of allowed servers. Return 0 if okay,
* 1 if not matched.
*/
int
verify(struct in_addr addr)
{
int i;
for (i = 0; i < RESTRICTED_SERVERS; i++)
if (!bcmp(&addr, &restricted_addrs[i], sizeof(struct in_addr)))
return(0);
return(1);
}
/*
* Try to set restricted mode. We default to normal mode if we can't
* resolve the specified hostnames.
*/
void
yp_restricted_mode(char *args)
{
struct hostent *h;
int i = 0;
char *s;
/* Find the restricted domain. */
if ((s = strsep(&args, ",")) == NULL)
return;
domain_name = s;
/* Get the addresses of the servers. */
while ((s = strsep(&args, ",")) != NULL && i < RESTRICTED_SERVERS) {
if ((h = gethostbyname(s)) == NULL)
return;
bcopy (h->h_addr_list[0], &restricted_addrs[i],
sizeof(struct in_addr));
i++;
}
/* ypset and ypsetme not allowed with restricted mode */
ypsetmode = YPSET_NO;
yp_restricted = i;
return;
}