1/* $NetBSD: getnetpath.c,v 1.3 2000/07/06 03:10:34 christos Exp $ */ 2 3/*- 4 * SPDX-License-Identifier: BSD-3-Clause 5 * 6 * Copyright (c) 2009, Sun Microsystems, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions are met: 11 * - Redistributions of source code must retain the above copyright notice, 12 * this list of conditions and the following disclaimer. 13 * - Redistributions in binary form must reproduce the above copyright notice, 14 * this list of conditions and the following disclaimer in the documentation 15 * and/or other materials provided with the distribution. 16 * - Neither the name of Sun Microsystems, Inc. nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; 35#endif 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD$"); 38 39/* 40 * Copyright (c) 1989 by Sun Microsystems, Inc. 41 */ 42 43#include "namespace.h" 44#include <stdio.h> 45#include <errno.h> 46#include <netconfig.h> 47#include <stdlib.h> 48#include <string.h> 49#include <syslog.h> 50#include "un-namespace.h" 51 52/* 53 * internal structure to keep track of a netpath "session" 54 */ 55struct netpath_chain { 56 struct netconfig *ncp; /* an nconf entry */ 57 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 58}; 59 60 61struct netpath_vars { 62 int valid; /* token that indicates a valid netpath_vars */ 63 void *nc_handlep; /* handle for current netconfig "session" */ 64 char *netpath; /* pointer to current view-point in NETPATH */ 65 char *netpath_start; /* pointer to start of our copy of NETPATH */ 66 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 67}; 68 69#define NP_VALID 0xf00d 70#define NP_INVALID 0 71 72char *_get_next_token(char *, int); 73 74 75/* 76 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 77 * must be called before the first call to getnetpath(). A "handle" is 78 * returned to distinguish the session; this handle should be passed 79 * subsequently to getnetpath(). (Handles are used to allow for nested calls 80 * to setnetpath()). 81 * If setnetpath() is unable to establish a session (due to lack of memory 82 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 83 * returned. 84 */ 85 86void * 87setnetpath(void) 88{ 89 90 struct netpath_vars *np_sessionp; /* this session's variables */ 91 char *npp; /* NETPATH env variable */ 92 93#ifdef MEM_CHK 94 malloc_debug(1); 95#endif 96 97 if ((np_sessionp = 98 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 99 return (NULL); 100 } 101 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 102 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 103 goto failed; 104 } 105 np_sessionp->valid = NP_VALID; 106 np_sessionp->ncp_list = NULL; 107 if ((npp = getenv(NETPATH)) == NULL) { 108 np_sessionp->netpath = NULL; 109 } else { 110 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 111 np_sessionp->nc_handlep = NULL; 112 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) 113 goto failed; 114 else { 115 (void) strcpy(np_sessionp->netpath, npp); 116 } 117 } 118 np_sessionp->netpath_start = np_sessionp->netpath; 119 return ((void *)np_sessionp); 120 121failed: 122 free(np_sessionp); 123 return (NULL); 124} 125 126/* 127 * When first called, getnetpath() returns a pointer to the netconfig 128 * database entry corresponding to the first valid NETPATH component. The 129 * netconfig entry is formatted as a struct netconfig. 130 * On each subsequent call, getnetpath returns a pointer to the netconfig 131 * entry that corresponds to the next valid NETPATH component. getnetpath 132 * can thus be used to search the netconfig database for all networks 133 * included in the NETPATH variable. 134 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns 135 * NULL and sets errno in case of an error (e.g., setnetpath was not called 136 * previously). 137 * getnetpath() silently ignores invalid NETPATH components. A NETPATH 138 * compnent is invalid if there is no corresponding entry in the netconfig 139 * database. 140 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH 141 * were set to the sequence of default or visible networks in the netconfig 142 * database, in the order in which they are listed. 143 */ 144 145struct netconfig * 146getnetpath(void *handlep) 147{ 148 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 149 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */ 150 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */ 151 char *npp; /* holds current NETPATH */ 152 153 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 154 errno = EINVAL; 155 return (NULL); 156 } 157 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */ 158 do { /* select next visible network */ 159 if (np_sessionp->nc_handlep == NULL) { 160 np_sessionp->nc_handlep = setnetconfig(); 161 if (np_sessionp->nc_handlep == NULL) 162 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 163 } 164 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) { 165 return(NULL); 166 } 167 } while ((ncp->nc_flag & NC_VISIBLE) == 0); 168 return (ncp); 169 } 170 /* 171 * Find first valid network ID in netpath. 172 */ 173 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) { 174 np_sessionp->netpath = _get_next_token(npp, ':'); 175 /* 176 * npp is a network identifier. 177 */ 178 if ((ncp = getnetconfigent(npp)) != NULL) { 179 chainp = (struct netpath_chain *) /* cobble alloc chain entry */ 180 malloc(sizeof (struct netpath_chain)); 181 chainp->ncp = ncp; 182 chainp->nchain_next = NULL; 183 if (np_sessionp->ncp_list == NULL) { 184 np_sessionp->ncp_list = chainp; 185 } else { 186 np_sessionp->ncp_list->nchain_next = chainp; 187 } 188 return (ncp); 189 } 190 /* couldn't find this token in the database; go to next one. */ 191 } 192 return (NULL); 193} 194 195/* 196 * endnetpath() may be called to unbind NETPATH when processing is complete, 197 * releasing resources for reuse. It returns 0 on success and -1 on failure 198 * (e.g. if setnetpath() was not called previously. 199 */ 200int 201endnetpath(void *handlep) 202{ 203 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 204 struct netpath_chain *chainp, *lastp; 205 206 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 207 errno = EINVAL; 208 return (-1); 209 } 210 if (np_sessionp->nc_handlep != NULL) 211 endnetconfig(np_sessionp->nc_handlep); 212 if (np_sessionp->netpath_start != NULL) 213 free(np_sessionp->netpath_start); 214 for (chainp = np_sessionp->ncp_list; chainp != NULL; 215 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 216 freenetconfigent(chainp->ncp); 217 } 218 free(np_sessionp); 219#ifdef MEM_CHK 220 if (malloc_verify() == 0) { 221 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 222 exit(1); 223 } 224#endif 225 return (0); 226} 227 228 229 230/* 231 * Returns pointer to the rest-of-the-string after the current token. 232 * The token itself starts at arg, and we null terminate it. We return NULL 233 * if either the arg is empty, or if this is the last token. 234 * 235 * npp - string 236 * token - char to parse string for 237 */ 238char * 239_get_next_token(char *npp, int token) 240{ 241 char *cp; /* char pointer */ 242 char *np; /* netpath pointer */ 243 char *ep; /* escape pointer */ 244 245 if ((cp = strchr(npp, token)) == NULL) { 246 return (NULL); 247 } 248 /* 249 * did find a token, but it might be escaped. 250 */ 251 if ((cp > npp) && (cp[-1] == '\\')) { 252 /* if slash was also escaped, carry on, otherwise find next token */ 253 if ((cp > npp + 1) && (cp[-2] != '\\')) { 254 /* shift r-o-s onto the escaped token */ 255 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 256 /* 257 * Do a recursive call. 258 * We don't know how many escaped tokens there might be. 259 */ 260 return (_get_next_token(cp, token)); 261 } 262 } 263 264 *cp++ = '\0'; /* null-terminate token */ 265 /* get rid of any backslash escapes */ 266 ep = npp; 267 while ((np = strchr(ep, '\\')) != NULL) { 268 if (np[1] == '\\') 269 np++; 270 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 271 } 272 return (cp); /* return ptr to r-o-s */ 273} 274