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 /* 37 * Copyright (c) 1989 by Sun Microsystems, Inc. 38 */ 39 40 #include "namespace.h" 41 #include <stdio.h> 42 #include <errno.h> 43 #include <netconfig.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <syslog.h> 47 #include "un-namespace.h" 48 49 /* 50 * internal structure to keep track of a netpath "session" 51 */ 52 struct netpath_chain { 53 struct netconfig *ncp; /* an nconf entry */ 54 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 55 }; 56 57 58 struct netpath_vars { 59 int valid; /* token that indicates a valid netpath_vars */ 60 void *nc_handlep; /* handle for current netconfig "session" */ 61 char *netpath; /* pointer to current view-point in NETPATH */ 62 char *netpath_start; /* pointer to start of our copy of NETPATH */ 63 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 64 }; 65 66 #define NP_VALID 0xf00d 67 #define NP_INVALID 0 68 69 char *_get_next_token(char *, int); 70 71 72 /* 73 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 74 * must be called before the first call to getnetpath(). A "handle" is 75 * returned to distinguish the session; this handle should be passed 76 * subsequently to getnetpath(). (Handles are used to allow for nested calls 77 * to setnetpath()). 78 * If setnetpath() is unable to establish a session (due to lack of memory 79 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 80 * returned. 81 */ 82 83 void * 84 setnetpath(void) 85 { 86 87 struct netpath_vars *np_sessionp; /* this session's variables */ 88 char *npp; /* NETPATH env variable */ 89 90 #ifdef MEM_CHK 91 malloc_debug(1); 92 #endif 93 94 if ((np_sessionp = 95 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 96 return (NULL); 97 } 98 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 99 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 100 goto failed; 101 } 102 np_sessionp->valid = NP_VALID; 103 np_sessionp->ncp_list = NULL; 104 if ((npp = getenv(NETPATH)) == NULL) { 105 np_sessionp->netpath = NULL; 106 } else { 107 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 108 np_sessionp->nc_handlep = NULL; 109 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) 110 goto failed; 111 else { 112 (void) strcpy(np_sessionp->netpath, npp); 113 } 114 } 115 np_sessionp->netpath_start = np_sessionp->netpath; 116 return ((void *)np_sessionp); 117 118 failed: 119 free(np_sessionp); 120 return (NULL); 121 } 122 123 /* 124 * When first called, getnetpath() returns a pointer to the netconfig 125 * database entry corresponding to the first valid NETPATH component. The 126 * netconfig entry is formatted as a struct netconfig. 127 * On each subsequent call, getnetpath returns a pointer to the netconfig 128 * entry that corresponds to the next valid NETPATH component. getnetpath 129 * can thus be used to search the netconfig database for all networks 130 * included in the NETPATH variable. 131 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns 132 * NULL and sets errno in case of an error (e.g., setnetpath was not called 133 * previously). 134 * getnetpath() silently ignores invalid NETPATH components. A NETPATH 135 * component is invalid if there is no corresponding entry in the netconfig 136 * database. 137 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH 138 * were set to the sequence of default or visible networks in the netconfig 139 * database, in the order in which they are listed. 140 */ 141 142 struct netconfig * 143 getnetpath(void *handlep) 144 { 145 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 146 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */ 147 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */ 148 char *npp; /* holds current NETPATH */ 149 150 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 151 errno = EINVAL; 152 return (NULL); 153 } 154 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */ 155 do { /* select next visible network */ 156 if (np_sessionp->nc_handlep == NULL) { 157 np_sessionp->nc_handlep = setnetconfig(); 158 if (np_sessionp->nc_handlep == NULL) 159 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 160 } 161 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) { 162 return(NULL); 163 } 164 } while ((ncp->nc_flag & NC_VISIBLE) == 0); 165 return (ncp); 166 } 167 /* 168 * Find first valid network ID in netpath. 169 */ 170 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) { 171 np_sessionp->netpath = _get_next_token(npp, ':'); 172 /* 173 * npp is a network identifier. 174 */ 175 if ((ncp = getnetconfigent(npp)) != NULL) { 176 chainp = (struct netpath_chain *) /* cobble alloc chain entry */ 177 malloc(sizeof (struct netpath_chain)); 178 chainp->ncp = ncp; 179 chainp->nchain_next = NULL; 180 if (np_sessionp->ncp_list == NULL) { 181 np_sessionp->ncp_list = chainp; 182 } else { 183 np_sessionp->ncp_list->nchain_next = chainp; 184 } 185 return (ncp); 186 } 187 /* couldn't find this token in the database; go to next one. */ 188 } 189 return (NULL); 190 } 191 192 /* 193 * endnetpath() may be called to unbind NETPATH when processing is complete, 194 * releasing resources for reuse. It returns 0 on success and -1 on failure 195 * (e.g. if setnetpath() was not called previously. 196 */ 197 int 198 endnetpath(void *handlep) 199 { 200 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 201 struct netpath_chain *chainp, *lastp; 202 203 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 204 errno = EINVAL; 205 return (-1); 206 } 207 if (np_sessionp->nc_handlep != NULL) 208 endnetconfig(np_sessionp->nc_handlep); 209 if (np_sessionp->netpath_start != NULL) 210 free(np_sessionp->netpath_start); 211 for (chainp = np_sessionp->ncp_list; chainp != NULL; 212 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 213 freenetconfigent(chainp->ncp); 214 } 215 free(np_sessionp); 216 #ifdef MEM_CHK 217 if (malloc_verify() == 0) { 218 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 219 exit(1); 220 } 221 #endif 222 return (0); 223 } 224 225 226 227 /* 228 * Returns pointer to the rest-of-the-string after the current token. 229 * The token itself starts at arg, and we null terminate it. We return NULL 230 * if either the arg is empty, or if this is the last token. 231 * 232 * npp - string 233 * token - char to parse string for 234 */ 235 char * 236 _get_next_token(char *npp, int token) 237 { 238 char *cp; /* char pointer */ 239 char *np; /* netpath pointer */ 240 char *ep; /* escape pointer */ 241 242 if ((cp = strchr(npp, token)) == NULL) { 243 return (NULL); 244 } 245 /* 246 * did find a token, but it might be escaped. 247 */ 248 if ((cp > npp) && (cp[-1] == '\\')) { 249 /* if slash was also escaped, carry on, otherwise find next token */ 250 if ((cp > npp + 1) && (cp[-2] != '\\')) { 251 /* shift r-o-s onto the escaped token */ 252 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 253 /* 254 * Do a recursive call. 255 * We don't know how many escaped tokens there might be. 256 */ 257 return (_get_next_token(cp, token)); 258 } 259 } 260 261 *cp++ = '\0'; /* null-terminate token */ 262 /* get rid of any backslash escapes */ 263 ep = npp; 264 while ((np = strchr(ep, '\\')) != NULL) { 265 if (np[1] == '\\') 266 np++; 267 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 268 } 269 return (cp); /* return ptr to r-o-s */ 270 } 271