1 /* $NetBSD: getnetpath.c,v 1.9 2005/02/09 21:35:47 kleink Exp $ */ 2 3 /* 4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 5 * unrestricted use provided that this legend is included on all tape 6 * media and as a part of the software program in whole or part. Users 7 * may copy or modify Sun RPC without charge, but are not authorized 8 * to license or distribute it to anyone else except as part of a product or 9 * program developed by the user or with the express written consent of 10 * Sun Microsystems, Inc. 11 * 12 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 13 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 14 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 15 * 16 * Sun RPC is provided with no support and without any obligation on the 17 * part of Sun Microsystems, Inc. to assist in its use, correction, 18 * modification or enhancement. 19 * 20 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 21 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 22 * OR ANY PART THEREOF. 23 * 24 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 25 * or profits or other special, indirect and consequential damages, even if 26 * Sun has been advised of the possibility of such damages. 27 * 28 * Sun Microsystems, Inc. 29 * 2550 Garcia Avenue 30 * Mountain View, California 94043 31 */ 32 33 #include <sys/cdefs.h> 34 #if defined(LIBC_SCCS) && !defined(lint) 35 #if 0 36 static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; 37 #else 38 __RCSID("$NetBSD: getnetpath.c,v 1.9 2005/02/09 21:35:47 kleink Exp $"); 39 #endif 40 #endif 41 42 /* 43 * Copyright (c) 1989 by Sun Microsystems, Inc. 44 */ 45 46 #include "namespace.h" 47 #include <sys/cdefs.h> 48 #include <stdio.h> 49 #include <assert.h> 50 #include <errno.h> 51 #include <netconfig.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 56 #ifdef __weak_alias 57 __weak_alias(getnetpath,_getnetpath) 58 __weak_alias(setnetpath,_setnetpath) 59 __weak_alias(endnetpath,_endnetpath) 60 #endif 61 62 /* 63 * internal structure to keep track of a netpath "session" 64 */ 65 struct netpath_chain { 66 struct netconfig *ncp; /* an nconf entry */ 67 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 68 }; 69 70 71 struct netpath_vars { 72 int valid; /* token that indicates a valid netpath_vars */ 73 void *nc_handlep; /* handle for current netconfig "session" */ 74 char *netpath; /* pointer to current view-point in NETPATH */ 75 char *netpath_start; /* pointer to start of our copy of NETPATH */ 76 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 77 }; 78 79 #define NP_VALID 0xf00d 80 #define NP_INVALID 0 81 82 char *_get_next_token __P((char *, int)); 83 84 85 /* 86 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 87 * must be called before the first call to getnetpath(). A "handle" is 88 * returned to distinguish the session; this handle should be passed 89 * subsequently to getnetpath(). (Handles are used to allow for nested calls 90 * to setnetpath()). 91 * If setnetpath() is unable to establish a session (due to lack of memory 92 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 93 * returned. 94 */ 95 96 void * 97 setnetpath() 98 { 99 struct netpath_vars *np_sessionp; /* this session's variables */ 100 char *npp; /* NETPATH env variable */ 101 102 #ifdef MEM_CHK 103 malloc_debug(1); 104 #endif 105 106 if ((np_sessionp = (struct netpath_vars *) 107 malloc(sizeof (struct netpath_vars))) == NULL) 108 return (NULL); 109 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 110 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 111 return (NULL); 112 } 113 np_sessionp->valid = NP_VALID; 114 np_sessionp->ncp_list = NULL; 115 if ((npp = getenv(NETPATH)) == NULL) 116 np_sessionp->netpath = NULL; 117 else { 118 (void) endnetconfig(np_sessionp->nc_handlep); 119 /* won't need nc session*/ 120 np_sessionp->nc_handlep = NULL; 121 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) { 122 free(np_sessionp); 123 return (NULL); 124 } else 125 (void) strcpy(np_sessionp->netpath, npp); 126 } 127 np_sessionp->netpath_start = np_sessionp->netpath; 128 return ((void *)np_sessionp); 129 } 130 131 /* 132 * When first called, getnetpath() returns a pointer to the netconfig 133 * database entry corresponding to the first valid NETPATH component. The 134 * netconfig entry is formatted as a struct netconfig. 135 * On each subsequent call, getnetpath returns a pointer to the netconfig 136 * entry that corresponds to the next valid NETPATH component. getnetpath 137 * can thus be used to search the netconfig database for all networks 138 * included in the NETPATH variable. 139 * When NETPATH has been exhausted, getnetpath() returns NULL. It returns 140 * NULL and sets errno in case of an error (e.g., setnetpath was not called 141 * previously). 142 * getnetpath() silently ignores invalid NETPATH components. A NETPATH 143 * compnent is invalid if there is no corresponding entry in the netconfig 144 * database. 145 * If the NETPATH variable is unset, getnetpath() behaves as if NETPATH 146 * were set to the sequence of default or visible networks in the netconfig 147 * database, in the order in which they are listed. 148 */ 149 150 struct netconfig * 151 getnetpath(handlep) 152 void *handlep; 153 { 154 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 155 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */ 156 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */ 157 char *npp; /* holds current NETPATH */ 158 159 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 160 errno = EINVAL; 161 return (NULL); 162 } 163 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */ 164 do { /* select next visible network */ 165 if (np_sessionp->nc_handlep == NULL) { 166 np_sessionp->nc_handlep = setnetconfig(); 167 if (np_sessionp->nc_handlep == NULL) 168 syslog (LOG_ERR, 169 "rpc: failed to open " NETCONFIG); 170 } 171 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) 172 == NULL) 173 return(NULL); 174 } while ((ncp->nc_flag & NC_VISIBLE) == 0); 175 return (ncp); 176 } 177 /* 178 * Find first valid network ID in netpath. 179 */ 180 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) { 181 np_sessionp->netpath = _get_next_token(npp, ':'); 182 /* 183 * npp is a network identifier. 184 */ 185 if ((ncp = getnetconfigent(npp)) != NULL) { 186 /* cobble alloc chain entry */ 187 chainp = (struct netpath_chain *) 188 malloc(sizeof (struct netpath_chain)); 189 chainp->ncp = ncp; 190 chainp->nchain_next = NULL; 191 if (np_sessionp->ncp_list == NULL) 192 np_sessionp->ncp_list = chainp; 193 else 194 np_sessionp->ncp_list->nchain_next = chainp; 195 return (ncp); 196 } 197 /* couldn't find this token in the database; go to next one. */ 198 } 199 return (NULL); 200 } 201 202 /* 203 * endnetpath() may be called to unbind NETPATH when processing is complete, 204 * releasing resources for reuse. It returns 0 on success and -1 on failure 205 * (e.g. if setnetpath() was not called previously. 206 */ 207 int 208 endnetpath(handlep) 209 void *handlep; 210 { 211 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 212 struct netpath_chain *chainp, *lastp; 213 214 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 215 errno = EINVAL; 216 return (-1); 217 } 218 if (np_sessionp->nc_handlep != NULL) 219 endnetconfig(np_sessionp->nc_handlep); 220 if (np_sessionp->netpath_start != NULL) 221 free(np_sessionp->netpath_start); 222 for (chainp = np_sessionp->ncp_list; chainp != NULL; 223 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 224 freenetconfigent(chainp->ncp); 225 } 226 free(np_sessionp); 227 #ifdef MEM_CHK 228 if (malloc_verify() == 0) { 229 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 230 exit(1); 231 } 232 #endif 233 return (0); 234 } 235 236 237 /* 238 * Returns pointer to the rest-of-the-string after the current token. 239 * The token itself starts at arg, and we null terminate it. We return NULL 240 * if either the arg is empty, or if this is the last token. 241 */ 242 243 char * 244 _get_next_token(npp, token) 245 char *npp; /* string */ 246 int token; /* char to parse string for */ 247 { 248 char *cp; /* char pointer */ 249 char *np; /* netpath pointer */ 250 char *ep; /* escape pointer */ 251 252 _DIAGASSERT(npp != NULL); 253 _DIAGASSERT(token != NULL); 254 255 if ((cp = strchr(npp, token)) == NULL) 256 return (NULL); 257 /* 258 * did find a token, but it might be escaped. 259 */ 260 if ((cp > npp) && (cp[-1] == '\\')) { 261 /* 262 * if slash was also escaped, carry on, otherwise find 263 * next token 264 */ 265 if ((cp > npp + 1) && (cp[-2] != '\\')) { 266 /* shift r-o-s onto the escaped token */ 267 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 268 /* 269 * Do a recursive call. 270 * We don't know how many escaped tokens there might be. 271 */ 272 return (_get_next_token(cp, token)); 273 } 274 } 275 276 *cp++ = '\0'; /* null-terminate token */ 277 /* get rid of any backslash escapes */ 278 ep = npp; 279 while ((np = strchr(ep, '\\')) != 0) { 280 if (np[1] == '\\') 281 np++; 282 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 283 } 284 return (cp); /* return ptr to r-o-s */ 285 } 286