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) 34 static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; 35 #endif 36 #include <sys/cdefs.h> 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 */ 53 struct netpath_chain { 54 struct netconfig *ncp; /* an nconf entry */ 55 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 56 }; 57 58 59 struct 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 70 char *_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 84 void * 85 setnetpath(void) 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 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 101 goto failed; 102 } 103 np_sessionp->valid = NP_VALID; 104 np_sessionp->ncp_list = NULL; 105 if ((npp = getenv(NETPATH)) == NULL) { 106 np_sessionp->netpath = NULL; 107 } else { 108 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 109 np_sessionp->nc_handlep = NULL; 110 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) 111 goto failed; 112 else { 113 (void) strcpy(np_sessionp->netpath, npp); 114 } 115 } 116 np_sessionp->netpath_start = np_sessionp->netpath; 117 return ((void *)np_sessionp); 118 119 failed: 120 free(np_sessionp); 121 return (NULL); 122 } 123 124 /* 125 * When first called, getnetpath() returns a pointer to the netconfig 126 * database entry corresponding to the first valid NETPATH component. The 127 * netconfig entry is formatted as a struct netconfig. 128 * On each subsequent call, getnetpath returns a pointer to the netconfig 129 * entry that corresponds to the next valid NETPATH component. getnetpath 130 * can thus be used to search the netconfig database for all networks 131 * included in the NETPATH variable. 132 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns 133 * NULL and sets errno in case of an error (e.g., setnetpath was not called 134 * previously). 135 * getnetpath() silently ignores invalid NETPATH components. A NETPATH 136 * component is invalid if there is no corresponding entry in the netconfig 137 * database. 138 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH 139 * were set to the sequence of default or visible networks in the netconfig 140 * database, in the order in which they are listed. 141 */ 142 143 struct netconfig * 144 getnetpath(void *handlep) 145 { 146 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 147 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */ 148 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */ 149 char *npp; /* holds current NETPATH */ 150 151 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 152 errno = EINVAL; 153 return (NULL); 154 } 155 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */ 156 do { /* select next visible network */ 157 if (np_sessionp->nc_handlep == NULL) { 158 np_sessionp->nc_handlep = setnetconfig(); 159 if (np_sessionp->nc_handlep == NULL) 160 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 161 } 162 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) { 163 return(NULL); 164 } 165 } while ((ncp->nc_flag & NC_VISIBLE) == 0); 166 return (ncp); 167 } 168 /* 169 * Find first valid network ID in netpath. 170 */ 171 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) { 172 np_sessionp->netpath = _get_next_token(npp, ':'); 173 /* 174 * npp is a network identifier. 175 */ 176 if ((ncp = getnetconfigent(npp)) != NULL) { 177 chainp = (struct netpath_chain *) /* cobble alloc chain entry */ 178 malloc(sizeof (struct netpath_chain)); 179 chainp->ncp = ncp; 180 chainp->nchain_next = NULL; 181 if (np_sessionp->ncp_list == NULL) { 182 np_sessionp->ncp_list = chainp; 183 } else { 184 np_sessionp->ncp_list->nchain_next = chainp; 185 } 186 return (ncp); 187 } 188 /* couldn't find this token in the database; go to next one. */ 189 } 190 return (NULL); 191 } 192 193 /* 194 * endnetpath() may be called to unbind NETPATH when processing is complete, 195 * releasing resources for reuse. It returns 0 on success and -1 on failure 196 * (e.g. if setnetpath() was not called previously. 197 */ 198 int 199 endnetpath(void *handlep) 200 { 201 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 202 struct netpath_chain *chainp, *lastp; 203 204 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 205 errno = EINVAL; 206 return (-1); 207 } 208 if (np_sessionp->nc_handlep != NULL) 209 endnetconfig(np_sessionp->nc_handlep); 210 if (np_sessionp->netpath_start != NULL) 211 free(np_sessionp->netpath_start); 212 for (chainp = np_sessionp->ncp_list; chainp != NULL; 213 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 214 freenetconfigent(chainp->ncp); 215 } 216 free(np_sessionp); 217 #ifdef MEM_CHK 218 if (malloc_verify() == 0) { 219 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 220 exit(1); 221 } 222 #endif 223 return (0); 224 } 225 226 227 228 /* 229 * Returns pointer to the rest-of-the-string after the current token. 230 * The token itself starts at arg, and we null terminate it. We return NULL 231 * if either the arg is empty, or if this is the last token. 232 * 233 * npp - string 234 * token - char to parse string for 235 */ 236 char * 237 _get_next_token(char *npp, int token) 238 { 239 char *cp; /* char pointer */ 240 char *np; /* netpath pointer */ 241 char *ep; /* escape pointer */ 242 243 if ((cp = strchr(npp, token)) == NULL) { 244 return (NULL); 245 } 246 /* 247 * did find a token, but it might be escaped. 248 */ 249 if ((cp > npp) && (cp[-1] == '\\')) { 250 /* if slash was also escaped, carry on, otherwise find next token */ 251 if ((cp > npp + 1) && (cp[-2] != '\\')) { 252 /* shift r-o-s onto the escaped token */ 253 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 254 /* 255 * Do a recursive call. 256 * We don't know how many escaped tokens there might be. 257 */ 258 return (_get_next_token(cp, token)); 259 } 260 } 261 262 *cp++ = '\0'; /* null-terminate token */ 263 /* get rid of any backslash escapes */ 264 ep = npp; 265 while ((np = strchr(ep, '\\')) != NULL) { 266 if (np[1] == '\\') 267 np++; 268 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 269 } 270 return (cp); /* return ptr to r-o-s */ 271 } 272