xref: /illumos-gate/usr/src/lib/libnls/common/nlsenv.c (revision 7c478bd9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
23 /*	  All Rights Reserved  	*/
24 
25 
26 /*
27  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 /*
34  * nlsenv.c:
35  *
36  * Utilities for servers to access environment set by listener.
37  *
38  * nlsgetcall:	Returns pointer to t_call structure listener recieved during
39  *		the t_listen.  Gets data from environment and converts
40  *		the data to internal address form.
41  *
42  * nlsprovider:	Returns name of provider from environment.
43  *
44  */
45 
46 #include <ctype.h>
47 #include <strings.h>
48 #include <sys/tiuser.h>
49 #include "listen.h"
50 
51 /*
52  * define DEBUGMODE for diagnostic printf's to stderr
53  */
54 
55 /* #define	DEBUGMODE */
56 
57 #ifdef	DEBUGMODE
58 #include <stdio.h>
59 #endif
60 
61 /*
62  * nlsenv: (static)
63  *
64  * Given an environment variable name, a receiving buffer and the length
65  * of the receiving buffer, getenv gets the environment variable, decodes
66  * it and places the decoded data in addr.  The return value is the length
67  * of "addr" if succesful, or a negative value if unsuccessful.
68  */
69 
70 extern char *getenv();
71 
72 int
nlsenv(struct netbuf * buf,char * envname)73 nlsenv(struct netbuf *buf, char *envname)
74 {
75 	char *charaddr;
76 	extern char *calloc();
77 	extern int nlsc2addr();
78 	int length;
79 
80 	if (!(charaddr = getenv(envname)))
81 		return(-11);
82 
83 #ifdef	DEBUGMODE
84 	fprintf(stderr, "nlsenv: environ %s = %s len = %d\n",
85 		envname, charaddr, strlen(charaddr));
86 #endif
87 
88 	if ((int)strlen(charaddr) & 1)
89 		return(-12);
90 
91 	length = (strlen(charaddr) + 1) / 2;
92 	if (!(buf->buf = calloc(1, length)))
93 		return(-13);
94 	else
95 		buf->maxlen = length;
96 	return(nlsc2addr(buf->buf, buf->maxlen, charaddr));
97 }
98 
99 
100 /*
101  * nlsgetcall:	Get calling data provided by the client via the listener.
102  *
103  *		nlsgetcall allows network server processes started by the
104  *		network listener process to access the callers 't_call'
105  *		structure provided in the client's t_connect primitive.
106  *
107  *		This routine gets this data from the environment
108  *		via putenv(3C), interprets the data and places the data
109  *		in a t_call structure allocated via t_alloc.
110  *
111  *		synopsis:
112  *
113  *		struct t_call *nlsgetcall(fd);
114  *		int fd;		arg now ignored
115  *
116  *
117  *		returns:	Address of an allocated t_call structure
118  *				or
119  *				NULL for failure. (calloc failed)
120  *				If calloc succeeds, non-existant
121  *				env. variables or data is indicated
122  *				by a negative 'len' field in the approp.
123  *				netbuf structure.  A length of zero in the
124  *				netbuf structure is valid.
125  *
126  */
127 
128 struct t_call *
nlsgetcall(int fd)129 nlsgetcall(int fd)
130 {
131 	struct t_call *call;
132 	extern char *calloc();
133 
134 	if (!(call = (struct t_call *) calloc(1, sizeof(struct t_call))))
135 		return((struct t_call *)0);
136 
137 /*
138  * Note: space for buffers gets allocated by nlsenv on the fly
139  */
140 
141 	call->addr.len = nlsenv(&call->addr, NLSADDR);
142 	call->opt.len = nlsenv(&call->opt, NLSOPT);
143 	call->udata.len = nlsenv(&call->udata, NLSUDATA);
144 
145 	return (call);
146 }
147 
148 
149 /*
150  * nlsprovider:	Return the name of the transport provider
151  *		as placed in the environment by the Network listener
152  *		process.  If the variable is not defined in the
153  *		environment, a NULL pointer is returned.
154  *
155  *		If the provider is "/dev/starlan", nlsprovider
156  *		returns a pointer to the null terminated character string:
157  *		"/dev/starlan" if this calling process is a child of the
158  *		network listener process.
159  */
160 
161 char *
nlsprovider()162 nlsprovider()
163 {
164 	return(getenv(NLSPROVIDER));
165 }
166 
167 
168 /*
169  * nlsc2addr:	Convert external address to internal form.
170  *	(from nlsaddr.c)
171  */
172 
173 /*
174  * asctohex(X):  convert char X to integer value
175  *		 assumes isxdigit(X). returns integer value.
176  *		 Note that 'a' > 'A'.  See usage in code below.
177  */
178 
179 #define asctohex(X)	\
180     ((int)(isdigit(X) ? (int)(X-'0') : (X>='a') ? (X-'a')+10 : (X-'A')+10))
181 
182 /*
183  * nlsc2addr:	Given a buffer containing the hex/ascii representation
184  *		of a logical address, the buffer's size and an address
185  *		of a receiving buffer, char2addr converts the logical
186  *		addr to internal format and returns the size of the logical
187  *		address.  A negative value is returned and the receiving
188  *		buffers contents are undefined if:
189  *
190  *		A.  The receiving buffer is not large enough. (rc = -1)
191  *		B.  If 'charaddr' does not contain a series of octets
192  *		    (strlen(charaddr) must be even). (rc = -2)
193  *		C.  Any character in 'charaddr' is not an ASCII hex digit.
194  *		    (rc = -3)
195  *
196  *	NOTE: that even if the internal representation of an address is
197  *	an ASCII string, there is no guarantee that the output will be
198  *	null terminated, thus the returned length must be used when
199  *	accessing the internal address.
200  */
201 
202 
203 int
nlsc2addr(char * addr,int maxlen,char * charaddr)204 nlsc2addr(char *addr, int maxlen, char *charaddr)
205 {
206 	int len;
207 	int i;
208 	char c;
209 	unsigned char val;
210 
211 	if (strlen(charaddr) & 1)
212 		return(-1);
213 
214 	for (len = 0; ((maxlen--) && (*charaddr)); ++len)  {
215 		for (i = 2,  val = 0;  i--;  )  {
216 			c = *charaddr++;
217 			if (!(isxdigit(c)))
218 				return(-3);
219 			val = (val << 4) | (unsigned char)asctohex(c);
220 	    	}
221 
222 		*addr++ = (char)val;
223 	}
224 
225 #ifdef	DEBUGMODE
226 	fprintf(stderr, "nlsc2addr: returned length = %d\n", len);
227 #endif
228 
229 	return(*charaddr ? -2 : len);
230 }
231