1/* $NetBSD: getnetpath.c,v 1.3 2000/07/06 03:10:34 christos Exp $ */ 2 3/*- 4 * Copyright (c) 2009, Sun Microsystems, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are met: 9 * - Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * - Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * - Neither the name of Sun Microsystems, Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived 16 * from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#if defined(LIBC_SCCS) && !defined(lint) 32static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; 33#endif 34#include <sys/cdefs.h> 35__FBSDID("$FreeBSD$"); 36 37/* 38 * Copyright (c) 1989 by Sun Microsystems, Inc. 39 */ 40 41#include "namespace.h" 42#include <stdio.h> 43#include <errno.h> 44#include <netconfig.h> 45#include <stdlib.h> 46#include <string.h> 47#include <syslog.h> 48#include "un-namespace.h" 49 50/* 51 * internal structure to keep track of a netpath "session" 52 */ 53struct netpath_chain { 54 struct netconfig *ncp; /* an nconf entry */ 55 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 56}; 57 58 59struct netpath_vars { 60 int valid; /* token that indicates a valid netpath_vars */ 61 void *nc_handlep; /* handle for current netconfig "session" */ 62 char *netpath; /* pointer to current view-point in NETPATH */ 63 char *netpath_start; /* pointer to start of our copy of NETPATH */ 64 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 65}; 66 67#define NP_VALID 0xf00d 68#define NP_INVALID 0 69 70char *_get_next_token(char *, int); 71 72 73/* 74 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 75 * must be called before the first call to getnetpath(). A "handle" is 76 * returned to distinguish the session; this handle should be passed 77 * subsequently to getnetpath(). (Handles are used to allow for nested calls 78 * to setnetpath()). 79 * If setnetpath() is unable to establish a session (due to lack of memory 80 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 81 * returned. 82 */ 83 84void * 85setnetpath() 86{ 87 88 struct netpath_vars *np_sessionp; /* this session's variables */ 89 char *npp; /* NETPATH env variable */ 90 91#ifdef MEM_CHK 92 malloc_debug(1); 93#endif 94 95 if ((np_sessionp = 96 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 97 return (NULL); 98 } 99 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 100 free(np_sessionp); 101 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 102 return (NULL); 103 } 104 np_sessionp->valid = NP_VALID; 105 np_sessionp->ncp_list = NULL; 106 if ((npp = getenv(NETPATH)) == NULL) { 107 np_sessionp->netpath = NULL; 108 } else { 109 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 110 np_sessionp->nc_handlep = NULL; 111 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) 112 goto failed; 113 else { 114 (void) strcpy(np_sessionp->netpath, npp); 115 } 116 } 117 np_sessionp->netpath_start = np_sessionp->netpath; 118 return ((void *)np_sessionp); 119 120failed: 121 free(np_sessionp); 122 return (NULL); 123} 124 125/* 126 * When first called, getnetpath() returns a pointer to the netconfig 127 * database entry corresponding to the first valid NETPATH component. The 128 * netconfig entry is formatted as a struct netconfig. 129 * On each subsequent call, getnetpath returns a pointer to the netconfig 130 * entry that corresponds to the next valid NETPATH component. getnetpath 131 * can thus be used to search the netconfig database for all networks 132 * included in the NETPATH variable. 133 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns 134 * NULL and sets errno in case of an error (e.g., setnetpath was not called 135 * previously). 136 * getnetpath() silently ignores invalid NETPATH components. A NETPATH 137 * compnent is invalid if there is no corresponding entry in the netconfig 138 * database. 139 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH 140 * were set to the sequence of default or visible networks in the netconfig 141 * database, in the order in which they are listed. 142 */ 143 144struct netconfig * 145getnetpath(handlep) 146 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(handlep) 202 void *handlep; 203{ 204 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 205 struct netpath_chain *chainp, *lastp; 206 207 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 208 errno = EINVAL; 209 return (-1); 210 } 211 if (np_sessionp->nc_handlep != NULL) 212 endnetconfig(np_sessionp->nc_handlep); 213 if (np_sessionp->netpath_start != NULL) 214 free(np_sessionp->netpath_start); 215 for (chainp = np_sessionp->ncp_list; chainp != NULL; 216 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 217 freenetconfigent(chainp->ncp); 218 } 219 free(np_sessionp); 220#ifdef MEM_CHK 221 if (malloc_verify() == 0) { 222 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 223 exit(1); 224 } 225#endif 226 return (0); 227} 228 229 230 231/* 232 * Returns pointer to the rest-of-the-string after the current token. 233 * The token itself starts at arg, and we null terminate it. We return NULL 234 * if either the arg is empty, or if this is the last token. 235 */ 236 237char * 238_get_next_token(npp, token) 239char *npp; /* string */ 240int token; /* char to parse string for */ 241{ 242 char *cp; /* char pointer */ 243 char *np; /* netpath pointer */ 244 char *ep; /* escape pointer */ 245 246 if ((cp = strchr(npp, token)) == NULL) { 247 return (NULL); 248 } 249 /* 250 * did find a token, but it might be escaped. 251 */ 252 if ((cp > npp) && (cp[-1] == '\\')) { 253 /* if slash was also escaped, carry on, otherwise find next token */ 254 if ((cp > npp + 1) && (cp[-2] != '\\')) { 255 /* shift r-o-s onto the escaped token */ 256 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 257 /* 258 * Do a recursive call. 259 * We don't know how many escaped tokens there might be. 260 */ 261 return (_get_next_token(cp, token)); 262 } 263 } 264 265 *cp++ = '\0'; /* null-terminate token */ 266 /* get rid of any backslash escapes */ 267 ep = npp; 268 while ((np = strchr(ep, '\\')) != 0) { 269 if (np[1] == '\\') 270 np++; 271 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 272 } 273 return (cp); /* return ptr to r-o-s */ 274} 275