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 #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 __FBSDID("$FreeBSD$"); 38 39 /* 40 * Copyright (c) 1989 by Sun Microsystems, Inc. 41 */ 42 43 #include "namespace.h" 44 #include <sys/cdefs.h> 45 #include <stdio.h> 46 #include <errno.h> 47 #include <netconfig.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <syslog.h> 51 #include "un-namespace.h" 52 53 /* 54 * internal structure to keep track of a netpath "session" 55 */ 56 struct netpath_chain { 57 struct netconfig *ncp; /* an nconf entry */ 58 struct netpath_chain *nchain_next; /* next nconf entry allocated */ 59 }; 60 61 62 struct netpath_vars { 63 int valid; /* token that indicates a valid netpath_vars */ 64 void *nc_handlep; /* handle for current netconfig "session" */ 65 char *netpath; /* pointer to current view-point in NETPATH */ 66 char *netpath_start; /* pointer to start of our copy of NETPATH */ 67 struct netpath_chain *ncp_list; /* list of nconfs allocated this session*/ 68 }; 69 70 #define NP_VALID 0xf00d 71 #define NP_INVALID 0 72 73 char *_get_next_token(char *, int); 74 75 76 /* 77 * A call to setnetpath() establishes a NETPATH "session". setnetpath() 78 * must be called before the first call to getnetpath(). A "handle" is 79 * returned to distinguish the session; this handle should be passed 80 * subsequently to getnetpath(). (Handles are used to allow for nested calls 81 * to setnetpath()). 82 * If setnetpath() is unable to establish a session (due to lack of memory 83 * resources, or the absence of the /etc/netconfig file), a NULL pointer is 84 * returned. 85 */ 86 87 void * 88 setnetpath() 89 { 90 91 struct netpath_vars *np_sessionp; /* this session's variables */ 92 char *npp; /* NETPATH env variable */ 93 94 #ifdef MEM_CHK 95 malloc_debug(1); 96 #endif 97 98 if ((np_sessionp = 99 (struct netpath_vars *)malloc(sizeof (struct netpath_vars))) == NULL) { 100 return (NULL); 101 } 102 if ((np_sessionp->nc_handlep = setnetconfig()) == NULL) { 103 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 104 return (NULL); 105 } 106 np_sessionp->valid = NP_VALID; 107 np_sessionp->ncp_list = NULL; 108 if ((npp = getenv(NETPATH)) == NULL) { 109 np_sessionp->netpath = NULL; 110 } else { 111 (void) endnetconfig(np_sessionp->nc_handlep);/* won't need nc session*/ 112 np_sessionp->nc_handlep = NULL; 113 if ((np_sessionp->netpath = malloc(strlen(npp)+1)) == NULL) { 114 free(np_sessionp); 115 return (NULL); 116 } else { 117 (void) strcpy(np_sessionp->netpath, npp); 118 } 119 } 120 np_sessionp->netpath_start = np_sessionp->netpath; 121 return ((void *)np_sessionp); 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 * compnent 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(handlep) 145 void *handlep; 146 { 147 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 148 struct netconfig *ncp = NULL; /* temp. holds a netconfig session */ 149 struct netpath_chain *chainp; /* holds chain of ncp's we alloc */ 150 char *npp; /* holds current NETPATH */ 151 152 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 153 errno = EINVAL; 154 return (NULL); 155 } 156 if (np_sessionp->netpath_start == NULL) { /* NETPATH was not set */ 157 do { /* select next visible network */ 158 if (np_sessionp->nc_handlep == NULL) { 159 np_sessionp->nc_handlep = setnetconfig(); 160 if (np_sessionp->nc_handlep == NULL) 161 syslog (LOG_ERR, "rpc: failed to open " NETCONFIG); 162 } 163 if ((ncp = getnetconfig(np_sessionp->nc_handlep)) == NULL) { 164 return(NULL); 165 } 166 } while ((ncp->nc_flag & NC_VISIBLE) == 0); 167 return (ncp); 168 } 169 /* 170 * Find first valid network ID in netpath. 171 */ 172 while ((npp = np_sessionp->netpath) != NULL && strlen(npp) != 0) { 173 np_sessionp->netpath = _get_next_token(npp, ':'); 174 /* 175 * npp is a network identifier. 176 */ 177 if ((ncp = getnetconfigent(npp)) != NULL) { 178 chainp = (struct netpath_chain *) /* cobble alloc chain entry */ 179 malloc(sizeof (struct netpath_chain)); 180 chainp->ncp = ncp; 181 chainp->nchain_next = NULL; 182 if (np_sessionp->ncp_list == NULL) { 183 np_sessionp->ncp_list = chainp; 184 } else { 185 np_sessionp->ncp_list->nchain_next = chainp; 186 } 187 return (ncp); 188 } 189 /* couldn't find this token in the database; go to next one. */ 190 } 191 return (NULL); 192 } 193 194 /* 195 * endnetpath() may be called to unbind NETPATH when processing is complete, 196 * releasing resources for reuse. It returns 0 on success and -1 on failure 197 * (e.g. if setnetpath() was not called previously. 198 */ 199 int 200 endnetpath(handlep) 201 void *handlep; 202 { 203 struct netpath_vars *np_sessionp = (struct netpath_vars *)handlep; 204 struct netpath_chain *chainp, *lastp; 205 206 if (np_sessionp == NULL || np_sessionp->valid != NP_VALID) { 207 errno = EINVAL; 208 return (-1); 209 } 210 if (np_sessionp->nc_handlep != NULL) 211 endnetconfig(np_sessionp->nc_handlep); 212 if (np_sessionp->netpath_start != NULL) 213 free(np_sessionp->netpath_start); 214 for (chainp = np_sessionp->ncp_list; chainp != NULL; 215 lastp=chainp, chainp=chainp->nchain_next, free(lastp)) { 216 freenetconfigent(chainp->ncp); 217 } 218 free(np_sessionp); 219 #ifdef MEM_CHK 220 if (malloc_verify() == 0) { 221 fprintf(stderr, "memory heap corrupted in endnetpath\n"); 222 exit(1); 223 } 224 #endif 225 return (0); 226 } 227 228 229 230 /* 231 * Returns pointer to the rest-of-the-string after the current token. 232 * The token itself starts at arg, and we null terminate it. We return NULL 233 * if either the arg is empty, or if this is the last token. 234 */ 235 236 char * 237 _get_next_token(npp, token) 238 char *npp; /* string */ 239 int token; /* char to parse string for */ 240 { 241 char *cp; /* char pointer */ 242 char *np; /* netpath pointer */ 243 char *ep; /* escape pointer */ 244 245 if ((cp = strchr(npp, token)) == NULL) { 246 return (NULL); 247 } 248 /* 249 * did find a token, but it might be escaped. 250 */ 251 if ((cp > npp) && (cp[-1] == '\\')) { 252 /* if slash was also escaped, carry on, otherwise find next token */ 253 if ((cp > npp + 1) && (cp[-2] != '\\')) { 254 /* shift r-o-s onto the escaped token */ 255 strcpy(&cp[-1], cp); /* XXX: overlapping string copy */ 256 /* 257 * Do a recursive call. 258 * We don't know how many escaped tokens there might be. 259 */ 260 return (_get_next_token(cp, token)); 261 } 262 } 263 264 *cp++ = '\0'; /* null-terminate token */ 265 /* get rid of any backslash escapes */ 266 ep = npp; 267 while ((np = strchr(ep, '\\')) != 0) { 268 if (np[1] == '\\') 269 np++; 270 strcpy(np, (ep = &np[1])); /* XXX: overlapping string copy */ 271 } 272 return (cp); /* return ptr to r-o-s */ 273 } 274