/* $NetBSD: getnetpath.c,v 1.18 2022/01/04 22:10:08 andvar Exp $ */ /* * Copyright (c) 2010, Oracle America, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 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. * * Neither the name of the "Oracle America, Inc." nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "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 * COPYRIGHT HOLDER OR CONTRIBUTORS 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> #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; #else __RCSID("$NetBSD: getnetpath.c,v 1.18 2022/01/04 22:10:08 andvar Exp $"); #endif #endif /* * Copyright (c) 1989 by Sun Microsystems, Inc. */ #include "namespace.h" #include <stdio.h> #include <assert.h> #include <errno.h> #include <netconfig.h> #include <stdlib.h> #include <string.h> #include <syslog.h> #ifdef __weak_alias __weak_alias(getnetpath,_getnetpath) __weak_alias(setnetpath,_setnetpath) __weak_alias(endnetpath,_endnetpath) #endif /* * 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(void) { struct netpath_vars *np_sessionp; /* this session's variables */ char *npp; /* NETPATH env variable */ #ifdef MEM_CHK malloc_debug(1); #endif if ((np_sessionp = malloc(sizeof(*np_sessionp))) == NULL) return (NULL); if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { free(np_sessionp); 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 * component 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(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) { /* cobble alloc chain entry */ chainp = malloc(sizeof (struct netpath_chain)); if (chainp == NULL) { freenetconfigent(ncp); return NULL; } 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(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( char *npp, /* string */ int token /* char to parse string for */ ) { char *cp; /* char pointer */ char *np; /* netpath pointer */ char *ep; /* escape pointer */ _DIAGASSERT(npp != NULL); 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 */ }
