1 /* $NetBSD: getnetpath.c,v 1.3 2000/07/06 03:10:34 christos 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 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 /* 41 * Copyright (c) 1989 by Sun Microsystems, Inc. 42 */ 43 44 #include "namespace.h" 45 #include <sys/cdefs.h> 46 #include <stdio.h> 47 #include <errno.h> 48 #include <netconfig.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <syslog.h> 52 #include "un-namespace.h" 53 54 /* 55 * internal structure to keep track of a netpath "session" 56 */ 57 struct netpath_chain { 58 struct netconfig *ncp; /* an nconf entry */ 59 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 60 }; 61 62 63 struct netpath_vars { 64 int valid; /* token that indicates a valid netpath_vars */ 65 void *nc_handlep; /* handle for current netconfig "session" */ 66 char *netpath; /* pointer to current view-point in NETPATH */ 67 char *netpath_start; /* pointer to start of our copy of NETPATH */ 68 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 69 }; 70 71 #define NP_VALID 0xf00d 72 #define NP_INVALID 0 73 74 char *_get_next_token(char *, int); 75 76 77 /* 78 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 79 * must be called before the first call to getnetpath(). A "handle" is 80 * returned to distinguish the session; this handle should be passed 81 * subsequently to getnetpath(). (Handles are used to allow for nested calls 82 * to setnetpath()). 83 * If setnetpath() is unable to establish a session (due to lack of memory 84 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 85 * returned. 86 */ 87 88 void * 89 setnetpath() 90 { 91 92 struct netpath_vars *np_sessionp; /* this session's variables */ 93 char *npp; /* NETPATH env variable */ 94 95 #ifdef MEM_CHK 96 malloc_debug(1); 97 #endif 98 99 if ((np_sessionp = 100 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 101 return (NULL); 102 } 103 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 104 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 105 return (NULL); 106 } 107 np_sessionp->valid = NP_VALID; 108 np_sessionp->ncp_list = NULL; 109 if ((npp = getenv(NETPATH)) == 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 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 */ 200 int 201 endnetpath(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 */ 236 237 char * 238 _get_next_token(npp, token) 239 char *npp; /* string */ 240 int 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[-1] == '\\') { 253 /* if slash was also escaped, carry on, otherwise find next token */ 254 if (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