freebsd-dev/lib/libc/yp/yplib.c

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/*
* 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.
*/
#ifndef LINT
static char *rcsid = "$Id: yplib.c,v 1.22 1996/06/04 17:35:15 jraynard Exp $";
#endif
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpcsvc/yp.h>
/*
* We have to define these here due to clashes between yp_prot.h and
* yp.h.
*/
struct dom_binding {
struct dom_binding *dom_pnext;
char dom_domain[YPMAXDOMAIN + 1];
struct sockaddr_in dom_server_addr;
u_short dom_server_port;
int dom_socket;
CLIENT *dom_client;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
u_short dom_local_port; /* now I finally know what this is for. */
long dom_vers;
};
#include <rpcsvc/ypclnt.h>
#ifndef BINDINGDIR
#define BINDINGDIR "/var/yp/binding"
#endif
#define YPMATCHCACHE
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
#define MAX_RETRIES 20
extern bool_t xdr_domainname(), xdr_ypbind_resp();
extern bool_t xdr_ypreq_key(), xdr_ypresp_val();
extern bool_t xdr_ypreq_nokey(), xdr_ypresp_key_val();
extern bool_t xdr_ypresp_all(), xdr_ypresp_all_seq();
extern bool_t xdr_ypresp_master();
int (*ypresp_allfn)();
void *ypresp_data;
struct dom_binding *_ypbindlist;
static char _yp_domain[MAXHOSTNAMELEN];
int _yplib_timeout = 10;
#ifdef YPMATCHCACHE
int _yplib_cache = 5;
static struct ypmatch_ent {
struct ypmatch_ent *next;
char *map, *key, *val;
int keylen, vallen;
time_t expire_t;
} *ypmc;
static void
ypmatch_add(map, key, keylen, val, vallen)
char *map;
char *key;
int keylen;
char *val;
int vallen;
{
struct ypmatch_ent *ep;
time_t t;
time(&t);
for(ep=ypmc; ep; ep=ep->next)
if(ep->expire_t < t)
break;
if(ep==NULL) {
ep = (struct ypmatch_ent *)malloc(sizeof *ep);
bzero((char *)ep, sizeof *ep);
if(ypmc)
ep->next = ypmc;
ypmc = ep;
}
if(ep->key)
free(ep->key);
if(ep->val)
free(ep->val);
ep->key = NULL;
ep->val = NULL;
ep->key = (char *)malloc(keylen);
if(ep->key==NULL)
return;
ep->val = (char *)malloc(vallen);
if(ep->key==NULL) {
free(ep->key);
ep->key = NULL;
return;
}
ep->keylen = keylen;
ep->vallen = vallen;
bcopy(key, ep->key, ep->keylen);
bcopy(val, ep->val, ep->vallen);
if(ep->map) {
if( strcmp(ep->map, map) ) {
free(ep->map);
ep->map = strdup(map);
}
} else {
ep->map = strdup(map);
}
ep->expire_t = t + _yplib_cache;
}
static bool_t
ypmatch_find(map, key, keylen, val, vallen)
char *map;
char *key;
int keylen;
char **val;
int *vallen;
{
struct ypmatch_ent *ep;
time_t t;
if(ypmc==NULL)
return 0;
time(&t);
for(ep=ypmc; ep; ep=ep->next) {
if(ep->keylen != keylen)
continue;
if(strcmp(ep->map, map))
continue;
if(bcmp(ep->key, key, keylen))
continue;
if(t > ep->expire_t)
continue;
*val = ep->val;
*vallen = ep->vallen;
return 1;
}
return 0;
}
#endif
char *
ypbinderr_string(incode)
int incode;
{
static char err[80];
switch(incode) {
case 0:
return "Success";
case YPBIND_ERR_ERR:
return "Internal ypbind error";
case YPBIND_ERR_NOSERV:
return "Domain not bound";
case YPBIND_ERR_RESC:
return "System resource allocation failure";
}
sprintf(err, "Unknown ypbind error: #%d\n", incode);
return err;
}
int
_yp_dobind(dom, ypdb)
char *dom;
struct dom_binding **ypdb;
{
static pid_t pid = -1;
char path[MAXPATHLEN];
struct dom_binding *ysd, *ysd2;
struct ypbind_resp ypbr;
struct timeval tv;
struct sockaddr_in clnt_sin;
int clnt_sock, fd;
pid_t gpid;
CLIENT *client;
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
int new = 0, r;
int retries = 0;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
struct sockaddr_in check;
int checklen = sizeof(struct sockaddr_in);
gpid = getpid();
if( !(pid==-1 || pid==gpid) ) {
ysd = _ypbindlist;
while(ysd) {
if(ysd->dom_client)
clnt_destroy(ysd->dom_client);
ysd2 = ysd->dom_pnext;
free(ysd);
ysd = ysd2;
}
_ypbindlist = NULL;
}
pid = gpid;
if(ypdb!=NULL)
*ypdb = NULL;
if(dom==NULL || strlen(dom)==0)
return YPERR_BADARGS;
for(ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext)
if( strcmp(dom, ysd->dom_domain) == 0)
break;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
if(ysd==NULL) {
ysd = (struct dom_binding *)malloc(sizeof *ysd);
bzero((char *)ysd, sizeof *ysd);
ysd->dom_socket = -1;
ysd->dom_vers = 0;
new = 1;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
} else {
/* Check the socket -- may have been hosed by the caller. */
if (getsockname(ysd->dom_socket, (struct sockaddr *)&check,
&checklen) == -1 || check.sin_family != AF_INET ||
check.sin_port != ysd->dom_local_port) {
/* Socket became bogus somehow... need to rebind. */
int save, sock;
sock = ysd->dom_socket;
save = dup(ysd->dom_socket);
clnt_destroy(ysd->dom_client);
ysd->dom_vers = 0;
ysd->dom_client = NULL;
sock = dup2(save, sock);
close(save);
}
}
- Make _do_ypbind() check for /var/run/ypbind.lock and attempt to flock() it before before trying to establish a binding. If /var/run/ypbind.lock doesn't exist, or if it exists and isn't locked, then ypbind isn't running, which means NIS is either turned off or hosed. - Have _yp_check() call yp_unbind() after it sucessfully calls yp_bind() to make sure it frees resources correctly. (I don't think there's really a memory leak here, but it seems somehow wrong to call yp_bind() without making a corresponding call to yp_unbind() afterwards.) This makes the NIS code behave a little better in cases where libc makes calls to NIS, but it isn't running correctly (i.e. there's no ypbind). This cleans up some strange libc behavior that manifests itself if you have the system domain name set, but aren't actually running NIS. In this event, the getrpcent(3) code could try to call into NIS and cause several inexplicable "clnttcp_create error: RPC program not registered" messages to appear. This happens because _yp_check() checks if the system domain name is set and, if it is, proceeds to call yp_bind() to attempt to establish a binding. Since there is no binding file (remember: ypbind isn't running, so /var/yp/binding will be empty), _yp_dobind() will attempt to contact ypbind to prod it into binding the domain. And because ypbind isn't running, the code generates the 'clnttcp_create' error. Ultimately the _yp_check() fails and the getrpcent(3) code rolls over to the /etc/rpc file, but the error messages are annoying, and the code should be smart enough to forgo the binding attempt when NIS is turned off.
1995-11-05 05:39:04 +00:00
again:
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
retries++;
if (retries > MAX_RETRIES) {
if (new)
free(ysd);
return(YPERR_YPBIND);
}
#ifdef BINDINGDIR
if(ysd->dom_vers==0) {
/*
* We're trying to make a new binding: zorch the
* existing handle now (if any).
*/
if(ysd->dom_client) {
clnt_destroy(ysd->dom_client);
ysd->dom_client = NULL;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
ysd->dom_socket = -1;
}
sprintf(path, "%s/%s.%d", BINDINGDIR, dom, 2);
if( (fd=open(path, O_RDONLY)) == -1) {
/* no binding file, YP is dead. */
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
/* Try to bring it back to life. */
close(fd);
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
goto skipit;
}
if( flock(fd, LOCK_EX|LOCK_NB) == -1 && errno==EWOULDBLOCK) {
struct iovec iov[2];
struct ypbind_resp ybr;
u_short ypb_port;
iov[0].iov_base = (caddr_t)&ypb_port;
iov[0].iov_len = sizeof ypb_port;
iov[1].iov_base = (caddr_t)&ybr;
iov[1].iov_len = sizeof ybr;
r = readv(fd, iov, 2);
if(r != iov[0].iov_len + iov[1].iov_len) {
close(fd);
ysd->dom_vers = -1;
goto again;
}
bzero(&ysd->dom_server_addr, sizeof ysd->dom_server_addr);
ysd->dom_server_addr.sin_family = AF_INET;
ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in);
ysd->dom_server_addr.sin_addr.s_addr =
*(u_long *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr;
ysd->dom_server_addr.sin_port =
*(u_short *)&ybr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port;
ysd->dom_server_port = ysd->dom_server_addr.sin_port;
close(fd);
goto gotit;
} else {
/* no lock on binding file, YP is dead. */
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
/* Try to bring it back to life. */
close(fd);
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
goto skipit;
}
}
skipit:
#endif
if(ysd->dom_vers==-1 || ysd->dom_vers==0) {
/*
* We're trying to make a new binding: zorch the
* existing handle now (if any).
*/
if(ysd->dom_client) {
clnt_destroy(ysd->dom_client);
ysd->dom_client = NULL;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
ysd->dom_socket = -1;
}
bzero((char *)&clnt_sin, sizeof clnt_sin);
clnt_sin.sin_family = AF_INET;
clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
1995-05-30 05:51:47 +00:00
clnt_sock = RPC_ANYSOCK;
client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS, &clnt_sock,
0, 0);
if(client==NULL) {
/*
* These conditions indicate ypbind just isn't
* alive -- we probably don't want to shoot our
* mouth off in this case; instead generate error
* messages only for really exotic problems.
*/
if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED &&
(rpc_createerr.cf_stat != RPC_SYSTEMERROR &&
rpc_createerr.cf_error.re_errno == ECONNREFUSED))
clnt_pcreateerror("clnttcp_create");
if(new)
free(ysd);
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
return (YPERR_YPBIND);
}
/*
* Check the port number -- should be < IPPORT_RESERVED.
* If not, it's possible someone has registered a bogus
* ypbind with the portmapper and is trying to trick us.
*/
if (ntohs(clnt_sin.sin_port) >= IPPORT_RESERVED) {
clnt_destroy(client);
if (new)
free(ysd);
return(YPERR_YPBIND);
}
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
tv.tv_sec = _yplib_timeout/2;
tv.tv_usec = 0;
r = clnt_call(client, YPBINDPROC_DOMAIN,
xdr_domainname, (char *)&dom, xdr_ypbind_resp, &ypbr, tv);
if(r != RPC_SUCCESS) {
clnt_destroy(client);
ysd->dom_vers = -1;
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
if (r == RPC_PROGUNAVAIL || r == RPC_PROCUNAVAIL) {
if (new)
free(ysd);
return(YPERR_YPBIND);
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
}
fprintf(stderr,
"YP: server for domain %s not responding, retrying\n", dom);
goto again;
} else {
if (ypbr.ypbind_status != YPBIND_SUCC_VAL) {
ypbind.c: Major overhaul. - Moved to a more client-driven model. We aggressively attempt to keep the default domain bound (as before) but we give up on non-default domains if we lose contact with a server and fail to get a response after one round of broadcasting. This helps drastically reduce the amount of network bandwitdh that ypbind consumes: if a client references the secondary domain at some later point, this will prod ypbind into establishing a new binding anyway, so continuously broadcasting without need is pointless. Note that we still actively seek out a binding for our default domain even if no client program has queried us yet. I'm not exactly sure if this matches SunOS's behavior or not, but I decided to do it this way since we can get into all sorts of trouble if our default domain comes unbound. Even so, we're still much quieter than we used to be. - Removed a bunch of no-longer pertinent comments and a couple of chunks of #ifdef 0'ed code that no longer fit in to the new layout. - Theo deRaadt must have become frustrated with the callback mechanism in clnt_broadcast(), because he shamelessly stole the clnt_broadcast() code right out of the RPC library and hacked it up to suit his needs. (Comments and all! :) I can understand why: clnt_broadcast() blocks while awaiting replies. Changing this behavior requires surgery. However, you can work around this: fork the broadcast into a child process and relay the results back to the parent via a pipe. (Careful obervation has shown that the SunOS ypbind forks children for broadcasting too, though I can only guess what sort of interprocess communication it uses. pipe() seems to do the job well enough.) This may seem like the long way around, but it's not really that hard to implement, and I'd prefer to use documented RPC library functions wherever possible. We're careful to limit the number of simultaneous broadcasters to avoid swamping the system (the current limit is 5). Each clnt_broadcast() call only sends out a small number of packets at increasing intervals. We're also careful not to spawn more than one bradcaster for a given domain. - Used clntudp_bufcreate() and clnt_call() to implement a ping() function for directly querying a particular server so that we can check if it's still alive. This lets me completely remove the old bradcasting code and use actual RPC library calls instead, at the cost of more than a few handfulls of torn-out hair. (Make no mistake folks: I *HATE* RPC.) Currently, the ping interval is one minute. - Fixed another potential 'nfds too big for select()' bug: use _rpc_dtablesize() instead of getdtablesize(). - Quieted gcc -Wall a bit. - Probably a bunch of other stuff that I've forgotten. ypbind.8: - Updated man page to reflect modifications. ypwhich.c: - Small mind-o fix from last time: decode error results from ypbind correctly (*groan*) yplib.c: - same as above - Change behavior of _yp_dobind() a little: if we get back a 'Domain not bound' error for a given domain, retry a few times before giving up and passing the error back to the caller. We have to sleep for a few seconds between tries since the 'Domain not bound' error comes back immediately (by repeatedly looping, we end up pounding on ypbind). We retry at most 20 times at 5 second intervals. This gives us a full minute to get a response. This seems to deviate a bit from SunOS behavior -- it appears to wait forever -- but I don't like the idea of perpetually hanging inside a library call. Note that this should fix the problems some people have with bindings not being established fast enough at boot time; sometimes amd is started in /etc/rc after ypbind has run but before it gets a binding set up. The automounter gets annoyed at this and tends to exit. By pausing ther YP calls until a binding is ready, we avoid this situation. - Another _yp_dobind() change: if we determine that our binding files are unlocked or nonexistent, jump directly to code that pokes ypbind into restablishing the binding. Again, if it fails, we'll time out eventually and return.
1995-04-26 19:03:16 +00:00
clnt_destroy(client);
ysd->dom_vers = -1;
sleep(_yplib_timeout/2);
goto again;
}
}
clnt_destroy(client);
bzero((char *)&ysd->dom_server_addr, sizeof ysd->dom_server_addr);
ysd->dom_server_addr.sin_family = AF_INET;
ysd->dom_server_addr.sin_port =
*(u_short *)&ypbr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port;
ysd->dom_server_addr.sin_addr.s_addr =
*(u_long *)&ypbr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_addr;
/*
* We could do a reserved port check here too, but this
* could pose compatibility problems. The local ypbind is
* supposed to decide whether or not to trust yp servers
* on insecure ports. For now, we trust its judgement.
*/
ysd->dom_server_port =
*(u_short *)&ypbr.ypbind_resp_u.ypbind_bindinfo.ypbind_binding_port;
gotit:
ysd->dom_vers = YPVERS;
strcpy(ysd->dom_domain, dom);
}
/* Don't rebuild the connection to the server unless we have to. */
if (ysd->dom_client == NULL) {
tv.tv_sec = _yplib_timeout/2;
tv.tv_usec = 0;
ysd->dom_socket = RPC_ANYSOCK;
ysd->dom_client = clntudp_create(&ysd->dom_server_addr,
YPPROG, YPVERS, tv, &ysd->dom_socket);
if(ysd->dom_client==NULL) {
clnt_pcreateerror("clntudp_create");
ysd->dom_vers = -1;
goto again;
}
if( fcntl(ysd->dom_socket, F_SETFD, 1) == -1)
perror("fcntl: F_SETFD");
Make _yp_dobind() a litle smarter: Now that we preserve RPC handles instead of rebuilding them each time a ypcln function is called, we have to be careful about keeping our sockets in a sane state. It's possible that the caller may call a ypclnt function, and then decide to close all its file descriptors. This would also close the socket descriptor held by the yplib code. Worse, it could re-open the same descriptor number for its own use. If it then calls another ypclnt function, the subsequent RPC will fail because the socket will either be gone or replaced with Something Completely Different. The yplib code will recover by rebinding, but it doing so it may wreck the descriptor which now belongs to the caller. To fix this, _yp_dobind() needs to label the descriptor somehow so that it can test it later to make sure it hasn't been altered between ypclnt calls. It does this by binding the socket, thus associating a port number with it. It then saves this port number in the dom_local_port member of the dom_binding structure for the given domain. When _yp_dobind() is called again (which it is at the start of each ypclnt function), it checks to see if the domain is already bound, and if it is, it does a getsockname() on the socket and compares the port number to the one it saved. If the getsockname() fails, or the port number doesn't match, it abandons the socket and sets up a new client handle. This still incurs some syscall overhead, which is what I was trying to avoid, but it's still not as bad as before.
1996-06-01 05:08:31 +00:00
/*
* We want a port number associated with this socket
* so that we can check its authenticity later.
*/
checklen = sizeof(struct sockaddr_in);
bzero((char *)&check, checklen);
bind(ysd->dom_socket, (struct sockaddr *)&check, checklen);
check.sin_family = AF_INET;
if (!getsockname(ysd->dom_socket,
(struct sockaddr *)&check, &checklen)) {
ysd->dom_local_port = check.sin_port;
} else {
clnt_destroy(ysd->dom_client);
if (new)
free(ysd);
return(YPERR_YPBIND);
}
}
if(new) {
ysd->dom_pnext = _ypbindlist;
_ypbindlist = ysd;
}
if(ypdb!=NULL)
*ypdb = ysd;
return 0;
}
static void
_yp_unbind(ypb)
struct dom_binding *ypb;
{
if (ypb->dom_client)
clnt_destroy(ypb->dom_client);
ypb->dom_client = NULL;
ypb->dom_socket = -1;
ypb->dom_vers = -1;
}
int
yp_bind(dom)
char *dom;
{
return _yp_dobind(dom, NULL);
}
void
yp_unbind(dom)
char *dom;
{
struct dom_binding *ypb, *ypbp;
ypbp = NULL;
for(ypb=_ypbindlist; ypb; ypb=ypb->dom_pnext) {
if( strcmp(dom, ypb->dom_domain) == 0) {
_yp_unbind(ypb);
if(ypbp)
ypbp->dom_pnext = ypb->dom_pnext;
else
_ypbindlist = ypb->dom_pnext;
free(ypb);
return;
}
ypbp = ypb;
}
return;
}
int
yp_match(indomain, inmap, inkey, inkeylen, outval, outvallen)
char *indomain;
char *inmap;
const char *inkey;
int inkeylen;
char **outval;
int *outvallen;
{
struct dom_binding *ysd;
struct ypresp_val yprv;
struct timeval tv;
struct ypreq_key yprk;
int r;
*outval = NULL;
*outvallen = 0;
/* Sanity check */
if (inkey == NULL || !strlen(inkey) || inkeylen <= 0 ||
inmap == NULL || !strlen(inmap) ||
indomain == NULL || !strlen(indomain))
return YPERR_BADARGS;
#ifdef YPMATCHCACHE
if( !strcmp(_yp_domain, indomain) && ypmatch_find(inmap, inkey,
inkeylen, &yprv.val.valdat_val, &yprv.val.valdat_len)) {
*outvallen = yprv.val.valdat_len;
*outval = (char *)malloc(*outvallen+1);
bcopy(yprv.val.valdat_val, *outval, *outvallen);
(*outval)[*outvallen] = '\0';
return 0;
}
#endif
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
yprk.domain = indomain;
yprk.map = inmap;
yprk.key.keydat_val = (char *)inkey;
yprk.key.keydat_len = inkeylen;
bzero((char *)&yprv, sizeof yprv);
r = clnt_call(ysd->dom_client, YPPROC_MATCH,
xdr_ypreq_key, &yprk, xdr_ypresp_val, &yprv, tv);
if(r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_match: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(yprv.stat)) ) {
*outvallen = yprv.val.valdat_len;
*outval = (char *)malloc(*outvallen+1);
bcopy(yprv.val.valdat_val, *outval, *outvallen);
(*outval)[*outvallen] = '\0';
#ifdef YPMATCHCACHE
if( strcmp(_yp_domain, indomain)==0 )
ypmatch_add(inmap, inkey, inkeylen, *outval, *outvallen);
#endif
}
xdr_free(xdr_ypresp_val, (char *)&yprv);
return r;
}
int
yp_get_default_domain(domp)
char **domp;
{
*domp = NULL;
if(_yp_domain[0] == '\0')
if( getdomainname(_yp_domain, sizeof _yp_domain))
return YPERR_NODOM;
*domp = _yp_domain;
return 0;
}
int
yp_first(indomain, inmap, outkey, outkeylen, outval, outvallen)
char *indomain;
char *inmap;
char **outkey;
int *outkeylen;
char **outval;
int *outvallen;
{
struct ypresp_key_val yprkv;
struct ypreq_nokey yprnk;
struct dom_binding *ysd;
struct timeval tv;
int r;
/* Sanity check */
if (indomain == NULL || !strlen(indomain) ||
inmap == NULL || !strlen(inmap))
return YPERR_BADARGS;
*outkey = *outval = NULL;
*outkeylen = *outvallen = 0;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
yprnk.domain = indomain;
yprnk.map = inmap;
bzero((char *)&yprkv, sizeof yprkv);
r = clnt_call(ysd->dom_client, YPPROC_FIRST,
xdr_ypreq_nokey, &yprnk, xdr_ypresp_key_val, &yprkv, tv);
if(r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_first: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(yprkv.stat)) ) {
*outkeylen = yprkv.key.keydat_len;
*outkey = (char *)malloc(*outkeylen+1);
bcopy(yprkv.key.keydat_val, *outkey, *outkeylen);
(*outkey)[*outkeylen] = '\0';
*outvallen = yprkv.val.valdat_len;
*outval = (char *)malloc(*outvallen+1);
bcopy(yprkv.val.valdat_val, *outval, *outvallen);
(*outval)[*outvallen] = '\0';
}
xdr_free(xdr_ypresp_key_val, (char *)&yprkv);
return r;
}
int
yp_next(indomain, inmap, inkey, inkeylen, outkey, outkeylen, outval, outvallen)
char *indomain;
char *inmap;
char *inkey;
int inkeylen;
char **outkey;
int *outkeylen;
char **outval;
int *outvallen;
{
struct ypresp_key_val yprkv;
struct ypreq_key yprk;
struct dom_binding *ysd;
struct timeval tv;
int r;
/* Sanity check */
if (inkey == NULL || !strlen(inkey) || inkeylen <= 0 ||
inmap == NULL || !strlen(inmap) ||
indomain == NULL || !strlen(indomain))
return YPERR_BADARGS;
*outkey = *outval = NULL;
*outkeylen = *outvallen = 0;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
yprk.domain = indomain;
yprk.map = inmap;
yprk.key.keydat_val = inkey;
yprk.key.keydat_len = inkeylen;
bzero((char *)&yprkv, sizeof yprkv);
r = clnt_call(ysd->dom_client, YPPROC_NEXT,
xdr_ypreq_key, &yprk, xdr_ypresp_key_val, &yprkv, tv);
if(r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_next: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(yprkv.stat)) ) {
*outkeylen = yprkv.key.keydat_len;
*outkey = (char *)malloc(*outkeylen+1);
bcopy(yprkv.key.keydat_val, *outkey, *outkeylen);
(*outkey)[*outkeylen] = '\0';
*outvallen = yprkv.val.valdat_len;
*outval = (char *)malloc(*outvallen+1);
bcopy(yprkv.val.valdat_val, *outval, *outvallen);
(*outval)[*outvallen] = '\0';
}
xdr_free(xdr_ypresp_key_val, (char *)&yprkv);
return r;
}
int
yp_all(indomain, inmap, incallback)
char *indomain;
char *inmap;
struct ypall_callback *incallback;
{
struct ypreq_nokey yprnk;
struct dom_binding *ysd;
struct timeval tv;
struct sockaddr_in clnt_sin;
CLIENT *clnt;
u_long status, savstat;
int clnt_sock;
/* Sanity check */
if (indomain == NULL || !strlen(indomain) ||
inmap == NULL || !strlen(inmap))
return YPERR_BADARGS;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
/* YPPROC_ALL manufactures its own channel to ypserv using TCP */
clnt_sock = RPC_ANYSOCK;
clnt_sin = ysd->dom_server_addr;
clnt_sin.sin_port = 0;
clnt = clnttcp_create(&clnt_sin, YPPROG, YPVERS, &clnt_sock, 0, 0);
if(clnt==NULL) {
printf("clnttcp_create failed\n");
return YPERR_PMAP;
}
yprnk.domain = indomain;
yprnk.map = inmap;
ypresp_allfn = incallback->foreach;
ypresp_data = (void *)incallback->data;
if (clnt_call(clnt, YPPROC_ALL,
xdr_ypreq_nokey, &yprnk,
xdr_ypresp_all_seq, &status, tv) != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_next: clnt_call");
clnt_destroy(clnt);
_yp_unbind(ysd);
goto again;
}
clnt_destroy(clnt);
savstat = status;
xdr_free(xdr_ypresp_all_seq, (char *)&status); /* not really needed... */
if(savstat != YP_NOMORE)
return ypprot_err(savstat);
return 0;
}
int
yp_order(indomain, inmap, outorder)
char *indomain;
char *inmap;
int *outorder;
{
struct dom_binding *ysd;
struct ypresp_order ypro;
struct ypreq_nokey yprnk;
struct timeval tv;
int r;
/* Sanity check */
if (indomain == NULL || !strlen(indomain) ||
inmap == NULL || !strlen(inmap))
return YPERR_BADARGS;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
yprnk.domain = indomain;
yprnk.map = inmap;
bzero((char *)(char *)&ypro, sizeof ypro);
r = clnt_call(ysd->dom_client, YPPROC_ORDER,
xdr_ypreq_nokey, &yprnk, xdr_ypresp_order, &ypro, tv);
if(r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_order: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(ypro.stat)) ) {
*outorder = ypro.ordernum;
}
xdr_free(xdr_ypresp_order, (char *)&ypro);
return (r);
}
int
yp_master(indomain, inmap, outname)
char *indomain;
char *inmap;
char **outname;
{
struct dom_binding *ysd;
struct ypresp_master yprm;
struct ypreq_nokey yprnk;
struct timeval tv;
int r;
/* Sanity check */
if (indomain == NULL || !strlen(indomain) ||
inmap == NULL || !strlen(inmap))
return YPERR_BADARGS;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
yprnk.domain = indomain;
yprnk.map = inmap;
bzero((char *)&yprm, sizeof yprm);
r = clnt_call(ysd->dom_client, YPPROC_MASTER,
xdr_ypreq_nokey, &yprnk, xdr_ypresp_master, &yprm, tv);
if(r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_master: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(yprm.stat)) ) {
*outname = (char *)strdup(yprm.peer);
}
xdr_free(xdr_ypresp_master, (char *)&yprm);
return (r);
}
int
yp_maplist(indomain, outmaplist)
char *indomain;
struct ypmaplist **outmaplist;
{
struct dom_binding *ysd;
struct ypresp_maplist ypml;
struct timeval tv;
int r;
/* Sanity check */
if (indomain == NULL || !strlen(indomain))
return YPERR_BADARGS;
again:
if( _yp_dobind(indomain, &ysd) != 0)
return YPERR_DOMAIN;
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
bzero((char *)&ypml, sizeof ypml);
r = clnt_call(ysd->dom_client, YPPROC_MAPLIST,
xdr_domainname,(char *)&indomain,xdr_ypresp_maplist,&ypml,tv);
if (r != RPC_SUCCESS) {
clnt_perror(ysd->dom_client, "yp_maplist: clnt_call");
_yp_unbind(ysd);
goto again;
}
if( !(r=ypprot_err(ypml.stat)) ) {
*outmaplist = ypml.maps;
}
/* NO: xdr_free(xdr_ypresp_maplist, &ypml);*/
return (r);
}
char *
yperr_string(incode)
int incode;
{
static char err[80];
switch(incode) {
case 0:
return "Success";
case YPERR_BADARGS:
return "Request arguments bad";
case YPERR_RPC:
return "RPC failure";
case YPERR_DOMAIN:
return "Can't bind to server which serves this domain";
case YPERR_MAP:
return "No such map in server's domain";
case YPERR_KEY:
return "No such key in map";
case YPERR_YPERR:
return "YP server error";
case YPERR_RESRC:
return "Local resource allocation failure";
case YPERR_NOMORE:
return "No more records in map database";
case YPERR_PMAP:
return "Can't communicate with portmapper";
case YPERR_YPBIND:
return "Can't communicate with ypbind";
case YPERR_YPSERV:
return "Can't communicate with ypserv";
case YPERR_NODOM:
return "Local domain name not set";
case YPERR_BADDB:
return "Server data base is bad";
case YPERR_VERS:
return "YP server version mismatch - server can't supply service.";
case YPERR_ACCESS:
return "Access violation";
case YPERR_BUSY:
return "Database is busy";
}
sprintf(err, "YP unknown error %d\n", incode);
return err;
}
int
ypprot_err(incode)
unsigned int incode;
{
switch(incode) {
case YP_TRUE:
return 0;
case YP_FALSE:
return YPERR_YPBIND;
case YP_NOMORE:
return YPERR_NOMORE;
case YP_NOMAP:
return YPERR_MAP;
case YP_NODOM:
return YPERR_DOMAIN;
case YP_NOKEY:
return YPERR_KEY;
case YP_BADOP:
return YPERR_YPERR;
case YP_BADDB:
return YPERR_BADDB;
case YP_YPERR:
return YPERR_YPERR;
case YP_BADARGS:
return YPERR_BADARGS;
case YP_VERS:
return YPERR_VERS;
}
return YPERR_YPERR;
}
int
_yp_check(dom)
char **dom;
{
char *unused;
if( _yp_domain[0]=='\0' )
if( yp_get_default_domain(&unused) )
return 0;
if(dom)
*dom = _yp_domain;
- Make _do_ypbind() check for /var/run/ypbind.lock and attempt to flock() it before before trying to establish a binding. If /var/run/ypbind.lock doesn't exist, or if it exists and isn't locked, then ypbind isn't running, which means NIS is either turned off or hosed. - Have _yp_check() call yp_unbind() after it sucessfully calls yp_bind() to make sure it frees resources correctly. (I don't think there's really a memory leak here, but it seems somehow wrong to call yp_bind() without making a corresponding call to yp_unbind() afterwards.) This makes the NIS code behave a little better in cases where libc makes calls to NIS, but it isn't running correctly (i.e. there's no ypbind). This cleans up some strange libc behavior that manifests itself if you have the system domain name set, but aren't actually running NIS. In this event, the getrpcent(3) code could try to call into NIS and cause several inexplicable "clnttcp_create error: RPC program not registered" messages to appear. This happens because _yp_check() checks if the system domain name is set and, if it is, proceeds to call yp_bind() to attempt to establish a binding. Since there is no binding file (remember: ypbind isn't running, so /var/yp/binding will be empty), _yp_dobind() will attempt to contact ypbind to prod it into binding the domain. And because ypbind isn't running, the code generates the 'clnttcp_create' error. Ultimately the _yp_check() fails and the getrpcent(3) code rolls over to the /etc/rpc file, but the error messages are annoying, and the code should be smart enough to forgo the binding attempt when NIS is turned off.
1995-11-05 05:39:04 +00:00
if( yp_bind(_yp_domain)==0 ) {
yp_unbind(_yp_domain);
return 1;
- Make _do_ypbind() check for /var/run/ypbind.lock and attempt to flock() it before before trying to establish a binding. If /var/run/ypbind.lock doesn't exist, or if it exists and isn't locked, then ypbind isn't running, which means NIS is either turned off or hosed. - Have _yp_check() call yp_unbind() after it sucessfully calls yp_bind() to make sure it frees resources correctly. (I don't think there's really a memory leak here, but it seems somehow wrong to call yp_bind() without making a corresponding call to yp_unbind() afterwards.) This makes the NIS code behave a little better in cases where libc makes calls to NIS, but it isn't running correctly (i.e. there's no ypbind). This cleans up some strange libc behavior that manifests itself if you have the system domain name set, but aren't actually running NIS. In this event, the getrpcent(3) code could try to call into NIS and cause several inexplicable "clnttcp_create error: RPC program not registered" messages to appear. This happens because _yp_check() checks if the system domain name is set and, if it is, proceeds to call yp_bind() to attempt to establish a binding. Since there is no binding file (remember: ypbind isn't running, so /var/yp/binding will be empty), _yp_dobind() will attempt to contact ypbind to prod it into binding the domain. And because ypbind isn't running, the code generates the 'clnttcp_create' error. Ultimately the _yp_check() fails and the getrpcent(3) code rolls over to the /etc/rpc file, but the error messages are annoying, and the code should be smart enough to forgo the binding attempt when NIS is turned off.
1995-11-05 05:39:04 +00:00
}
return 0;
}