FreeBSD-5.3/lib/libc/rpc/getnetpath.c
/* $NetBSD: getnetpath.c,v 1.3 2000/07/06 03:10:34 christos Exp $ */
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user or with the express written consent of
* Sun Microsystems, Inc.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
/*
#ifndef lint
static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI";
#endif
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/rpc/getnetpath.c,v 1.4 2003/01/27 22:36:53 mbr Exp $");
/*
* Copyright (c) 1989 by Sun Microsystems, Inc.
*/
#include "namespace.h"
#include <sys/cdefs.h>
#include <stdio.h>
#include <errno.h>
#include <netconfig.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include "un-namespace.h"
/*
* internal structure to keep track of a netpath "session"
*/
struct netpath_chain {
struct netconfig *ncp; /* an nconf entry */
struct netpath_chain *nchain_next; /* next nconf entry allocated */
};
struct netpath_vars {
int valid; /* token that indicates a valid netpath_vars */
void *nc_handlep; /* handle for current netconfig "session" */
char *netpath; /* pointer to current view-point in NETPATH */
char *netpath_start; /* pointer to start of our copy of NETPATH */
struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/
};
#define NP_VALID 0xf00d
#define NP_INVALID 0
char *_get_next_token(char *, int);
/*
* A call to setnetpath() establishes a NETPATH "session". setnetpath()
* must be called before the first call to getnetpath(). A "handle" is
* returned to distinguish the session; this handle should be passed
* subsequently to getnetpath(). (Handles are used to allow for nested calls
* to setnetpath()).
* If setnetpath() is unable to establish a session (due to lack of memory
* resources, or the absence of the /etc/netconfig file), a NULL pointer is
* returned.
*/
void *
setnetpath()
{
struct netpath_vars *np_sessionp; /* this session's variables */
char *npp; /* NETPATH env variable */
#ifdef MEM_CHK
malloc_debug(1);
#endif
if ((np_sessionp =
(struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) {
return (NULL);
}
if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) {
syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
return (NULL);
}
np_sessionp->valid = NP_VALID;
np_sessionp->ncp_list = NULL;
if ((npp = getenv(NETPATH)) == NULL) {
np_sessionp->netpath = NULL;
} else {
(void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/
np_sessionp->nc_handlep = NULL;
if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) {
free(np_sessionp);
return (NULL);
} else {
(void) strcpy(np_sessionp->netpath, npp);
}
}
np_sessionp->netpath_start = np_sessionp->netpath;
return ((void *)np_sessionp);
}
/*
* When first called, getnetpath() returns a pointer to the netconfig
* database entry corresponding to the first valid NETPATH component. The
* netconfig entry is formatted as a struct netconfig.
* On each subsequent call, getnetpath returns a pointer to the netconfig
* entry that corresponds to the next valid NETPATH component. getnetpath
* can thus be used to search the netconfig database for all networks
* included in the NETPATH variable.
* When NETPATH has been exhausted, getnetpath() returns NULL. It returns
* NULL and sets errno in case of an error (e.g., setnetpath was not called
* previously).
* getnetpath() silently ignores invalid NETPATH components. A NETPATH
* compnent is invalid if there is no corresponding entry in the netconfig
* database.
* If the NETPATH variable is unset, getnetpath() behaves as if NETPATH
* were set to the sequence of default or visible networks in the netconfig
* database, in the order in which they are listed.
*/
struct netconfig *
getnetpath(handlep)
void *handlep;
{
struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
struct netconfig *ncp = NULL; /* temp. holds a netconfig session */
struct netpath_chain *chainp; /* holds chain of ncp's we alloc */
char *npp; /* holds current NETPATH */
if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
errno = EINVAL;
return (NULL);
}
if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */
do { /* select next visible network */
if (np_sessionp->nc_handlep == NULL) {
np_sessionp->nc_handlep = setnetconfig();
if (np_sessionp->nc_handlep == NULL)
syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
}
if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) {
return(NULL);
}
} while ((ncp->nc_flag & NC_VISIBLE) == 0);
return (ncp);
}
/*
* Find first valid network ID in netpath.
*/
while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) {
np_sessionp->netpath = _get_next_token(npp, ':');
/*
* npp is a network identifier.
*/
if ((ncp = getnetconfigent(npp)) != NULL) {
chainp = (struct netpath_chain *) /* cobble alloc chain entry */
malloc(sizeof (struct netpath_chain));
chainp->ncp = ncp;
chainp->nchain_next = NULL;
if (np_sessionp->ncp_list == NULL) {
np_sessionp->ncp_list = chainp;
} else {
np_sessionp->ncp_list->nchain_next = chainp;
}
return (ncp);
}
/* couldn't find this token in the database; go to next one. */
}
return (NULL);
}
/*
* endnetpath() may be called to unbind NETPATH when processing is complete,
* releasing resources for reuse. It returns 0 on success and -1 on failure
* (e.g. if setnetpath() was not called previously.
*/
int
endnetpath(handlep)
void *handlep;
{
struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep;
struct netpath_chain *chainp, *lastp;
if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) {
errno = EINVAL;
return (-1);
}
if (np_sessionp->nc_handlep != NULL)
endnetconfig(np_sessionp->nc_handlep);
if (np_sessionp->netpath_start != NULL)
free(np_sessionp->netpath_start);
for (chainp = np_sessionp->ncp_list; chainp != NULL;
lastp=chainp, chainp=chainp->nchain_next, free(lastp)) {
freenetconfigent(chainp->ncp);
}
free(np_sessionp);
#ifdef MEM_CHK
if (malloc_verify() == 0) {
fprintf(stderr, "memory heap corrupted in endnetpath\n");
exit(1);
}
#endif
return (0);
}
/*
* Returns pointer to the rest-of-the-string after the current token.
* The token itself starts at arg, and we null terminate it. We return NULL
* if either the arg is empty, or if this is the last token.
*/
char *
_get_next_token(npp, token)
char *npp; /* string */
int token; /* char to parse string for */
{
char *cp; /* char pointer */
char *np; /* netpath pointer */
char *ep; /* escape pointer */
if ((cp = strchr(npp, token)) == NULL) {
return (NULL);
}
/*
* did find a token, but it might be escaped.
*/
if ((cp > npp) && (cp[-1] == '\\')) {
/* if slash was also escaped, carry on, otherwise find next token */
if ((cp > npp + 1) && (cp[-2] != '\\')) {
/* shift r-o-s onto the escaped token */
strcpy(&cp[-1], cp); /* XXX: overlapping string copy */
/*
* Do a recursive call.
* We don't know how many escaped tokens there might be.
*/
return (_get_next_token(cp, token));
}
}
*cp++ = '\0'; /* null-terminate token */
/* get rid of any backslash escapes */
ep = npp;
while ((np = strchr(ep, '\\')) != 0) {
if (np[1] == '\\')
np++;
strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */
}
return (cp); /* return ptr to r-o-s */
}