1 /* $NetBSD: getnetpath.c,v 1.1 2000/06/02 23:11:11 fvdl 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 #ifndef lint 34 static char sccsid[] = "@(#)getnetpath.c 1.11 91/12/19 SMI"; 35 #endif 36 */ 37 38 /* 39 * Copyright (c) 1989 by Sun Microsystems, Inc. 40 */ 41 42 #include "namespace.h" 43 #include <sys/cdefs.h> 44 #include <stdio.h> 45 #include <errno.h> 46 #include <netconfig.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 #ifdef __weak_alias 51 __weak_alias(getnetpath,_getnetpath) 52 __weak_alias(setnetpath,_setnetpath) 53 #endif 54 55 /* 56 * internal structure to keep track of a netpath "session" 57 */ 58 struct netpath_chain { 59 struct netconfig *ncp; /* an nconf entry */ 60 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 61 }; 62 63 64 struct netpath_vars { 65 int valid; /* token that indicates a valid netpath_vars */ 66 void *nc_handlep; /* handle for current netconfig "session" */ 67 char *netpath; /* pointer to current view-point in NETPATH */ 68 char *netpath_start; /* pointer to start of our copy of NETPATH */ 69 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 70 }; 71 72 #define NP_VALID 0xf00d 73 #define NP_INVALID 0 74 75 char *_get_next_token __P((char *, char)); 76 77 78 /* 79 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 80 * must be called before the first call to getnetpath(). A "handle" is 81 * returned to distinguish the session; this handle should be passed 82 * subsequently to getnetpath(). (Handles are used to allow for nested calls 83 * to setnetpath()). 84 * If setnetpath() is unable to establish a session (due to lack of memory 85 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 86 * returned. 87 */ 88 89 void * 90 setnetpath() 91 { 92 93 struct netpath_vars *np_sessionp; /* this session's variables */ 94 char *npp; /* NETPATH env variable */ 95 96 #ifdef MEM_CHK 97 malloc_debug(1); 98 #endif 99 100 if ((np_sessionp = 101 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 102 return (NULL); 103 } 104 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 105 return (NULL); 106 } 107 np_sessionp->valid = NP_VALID; 108 np_sessionp->ncp_list = NULL; 109 if ((npp = getenv(NETPATH)) == (char *)NULL) { 110 np_sessionp->netpath = NULL; 111 } else { 112 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 113 np_sessionp->nc_handlep = NULL; 114 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) { 115 free(np_sessionp); 116 return (NULL); 117 } else { 118 (void) strcpy(np_sessionp->netpath, npp); 119 } 120 } 121 np_sessionp->netpath_start = np_sessionp->netpath; 122 return ((void *)np_sessionp); 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 */ 143 144 struct netconfig * 145 getnetpath(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 } 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(handlep) 200 void *handlep; 201 { 202 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 203 struct netpath_chain *chainp, *lastp; 204 205 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 206 errno = EINVAL; 207 return (-1); 208 } 209 if (np_sessionp->nc_handlep != NULL) 210 endnetconfig(np_sessionp->nc_handlep); 211 if (np_sessionp->netpath_start != NULL) 212 free(np_sessionp->netpath_start); 213 for (chainp = np_sessionp->ncp_list; chainp != NULL; 214 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 215 freenetconfigent(chainp->ncp); 216 } 217 free(np_sessionp); 218 #ifdef MEM_CHK 219 if (malloc_verify() == 0) { 220 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 221 exit(1); 222 } 223 #endif 224 return (0); 225 } 226 227 228 229 /* 230 * Returns pointer to the rest-of-the-string after the current token. 231 * The token itself starts at arg, and we null terminate it. We return NULL 232 * if either the arg is empty, or if this is the last token. 233 */ 234 235 char * 236 _get_next_token(npp, token) 237 char *npp; /* string */ 238 char token; /* char to parse string for */ 239 { 240 char *cp; /* char pointer */ 241 char *np; /* netpath pointer */ 242 char *ep; /* escape pointer */ 243 244 if ((cp = strchr(npp, token)) == NULL) { 245 return (NULL); 246 } 247 /* 248 * did find a token, but it might be escaped. 249 */ 250 if (cp[-1] == '\\') { 251 /* if slash was also escaped, carry on, otherwise find next token */ 252 if (cp[-2] != '\\') { 253 /* shift r-o-s onto the escaped token */ 254 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 255 /* 256 * Do a recursive call. 257 * We don't know how many escaped tokens there might be. 258 */ 259 return (_get_next_token(cp, token)); 260 } 261 } 262 263 *cp++ = '\0'; /* null-terminate token */ 264 /* get rid of any backslash escapes */ 265 ep = npp; 266 while ((np = strchr(ep, '\\')) != 0) { 267 if (np[1] == '\\') 268 np++; 269 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 270 } 271 return (cp); /* return ptr to r-o-s */ 272 } 273