xref: /illumos-gate/usr/src/lib/libwrap/tcpd.h (revision a7cee4e9766ebda975dd156d1f10a70f51c242f0)
1 /*
2  * Copyright 2014 Sachidananda Urs <sacchi@gmail.com>
3  * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
4  * Use is subject to license terms.
5  */
6 
7 /*
8  * @(#) tcpd.h 1.5 96/03/19 16:22:24
9  *
10  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
11  */
12 
13 #ifndef	_TCPD_H
14 #define	_TCPD_H
15 
16 /*
17  * HAVE_IPV6 is traditionally configured at tcp_wrappers build time but for
18  * Solaris it must always be defined to keep the library interface binary
19  * compatible.
20  */
21 #define	HAVE_IPV6
22 
23 /* Structure to describe one communications endpoint. */
24 
25 #define	STRING_LENGTH	128		/* hosts, users, processes */
26 
27 #include <stdio_tag.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30 
31 typedef struct sockaddr_gen {
32     union {
33 	struct sockaddr	_sg_sa;
34 	struct sockaddr_in	_sg_sin;
35 #ifdef HAVE_IPV6
36 	struct sockaddr_in6	_sg_sin6;
37 #endif
38 	} sg_addr;
39 } sockaddr_gen;
40 
41 typedef union gen_addr {
42     struct in_addr	ga_in;
43 #ifdef HAVE_IPV6
44     struct in6_addr	ga_in6;
45 #endif
46 } gen_addr;
47 
48 extern void sockgen_simplify();
49 
50 #define	sg_sa		sg_addr._sg_sa
51 #define	sg_sin		sg_addr._sg_sin
52 #define	sg_sin6		sg_addr._sg_sin6
53 #define	sg_family	sg_sa.sa_family
54 #ifdef HAVE_IPV6
55 #define	SGADDRSZ(sag)		((sag)->sg_family == AF_INET6 ? \
56 				    sizeof (struct in6_addr) : \
57 				    sizeof (struct in_addr))
58 #define	SGSOCKADDRSZ(sag)	((sag)->sg_family == AF_INET6 ? \
59 				    sizeof (struct sockaddr_in6) : \
60 				    sizeof (struct sockaddr_in))
61 #define	SGPORT(sag)		(*((sag)->sg_family == AF_INET6 ? \
62 				    &(sag)->sg_sin6.sin6_port : \
63 				    &(sag)->sg_sin.sin_port))
64 #define	SGADDRP(sag)		(((sag)->sg_family == AF_INET6 ? \
65 				    (char *)&(sag)->sg_sin6.sin6_addr : \
66 				    (char *)&(sag)->sg_sin.sin_addr))
67 #define	SGFAM(sag)		((sag)->sg_family == AF_INET6 ? \
68 				    AF_INET6 : AF_INET)
69 
70 #define	SG_IS_UNSPECIFIED(sag) \
71 		((sag)->sg_family == AF_INET6 ? \
72 			IN6_IS_ADDR_UNSPECIFIED(&(sag)->sg_sin6.sin6_addr) : \
73 			(sag)->sg_sin.sin_addr.s_addr == 0)
74 
75 #define	VALID_ADDRTYPE(t)	((t) == AF_INET || (t) == AF_INET6)
76 
77 #ifndef IPV6_ABITS
78 #define	IPV6_ABITS 128			/* Size of IPV6 address in bits */
79 #endif
80 
81 #else /* HAVE_IPV6 */
82 
83 #define	SGADDRSZ(sag)		sizeof (struct in_addr)
84 #define	SGSOCKADDRSZ(sag)	sizeof (struct sockaddr_in)
85 #define	SGPORT(sag)		((sag)->sg_sin.sin_port)
86 #define	SGADDRP(sag)		((char *)&(sag)->sg_sin.sin_addr)
87 #define	SGFAM(sag)		AF_INET
88 #define	SG_IS_UNSPECIFIED(sag)  ((sag)->sg_sin.sin_addr.s_addr == 0)
89 
90 #define	VALID_ADDRTYPE(t)	((t) == AF_INET)
91 
92 #endif /* HAVE_IPV6 */
93 
94 struct host_info {
95     char    name[STRING_LENGTH];	/* access via eval_hostname(host) */
96     char    addr[STRING_LENGTH];	/* access via eval_hostaddr(host) */
97     struct sockaddr_gen *sin;		/* socket address or 0 */
98     struct t_unitdata *unit;		/* TLI transport address or 0 */
99     struct request_info *request;	/* for shared information */
100 };
101 
102 /* Structure to describe what we know about a service request. */
103 
104 struct request_info {
105     int	    fd;				/* socket handle */
106     char    user[STRING_LENGTH];	/* access via eval_user(request) */
107     char    daemon[STRING_LENGTH];	/* access via eval_daemon(request) */
108     char    pid[10];			/* access via eval_pid(request) */
109     struct host_info client[1];		/* client endpoint info */
110     struct host_info server[1];		/* server endpoint info */
111     void  (*sink) ();			/* datagram sink function or 0 */
112     void  (*hostname) ();		/* address to printable hostname */
113     void  (*hostaddr) ();		/* address to printable address */
114     void  (*cleanup) ();		/* cleanup function or 0 */
115     struct netconfig *config;		/* netdir handle */
116 };
117 
118 /* Common string operations. Less clutter should be more readable. */
119 
120 #define	STRN_CPY(d, s, l)	{ strncpy((d), (s), (l)); (d)[(l)-1] = 0; }
121 
122 #define	STRN_EQ(x, y, l)	(strncasecmp((x), (y), (l)) == 0)
123 #define	STRN_NE(x, y, l)	(strncasecmp((x), (y), (l)) != 0)
124 #define	STR_EQ(x, y)		(strcasecmp((x), (y)) == 0)
125 #define	STR_NE(x, y)		(strcasecmp((x), (y)) != 0)
126 
127 /*
128  * Initially, all above strings have the empty value. Information that
129  * cannot be determined at runtime is set to "unknown", so that we can
130  * distinguish between `unavailable' and `not yet looked up'. A hostname
131  * that we do not believe in is set to "paranoid".
132  */
133 
134 #define	STRING_UNKNOWN	"unknown"	/* lookup failed */
135 #define	STRING_PARANOID	"paranoid"	/* hostname conflict */
136 
137 extern char unknown[];
138 extern char paranoid[];
139 
140 #define	HOSTNAME_KNOWN(s) (STR_NE((s), unknown) && STR_NE((s), paranoid))
141 
142 #ifdef HAVE_IPV6
143 #define	NOT_INADDR(s) (strchr(s, ':') == 0 && s[strspn(s, "0123456789./")] != 0)
144 #else
145 #define	NOT_INADDR(s) (s[strspn(s, "0123456789./")] != 0)
146 #endif
147 
148 /* Global functions. */
149 
150 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
151 extern void fromhost();			/* get/validate client host info */
152 #else
153 #define	fromhost sock_host		/* no TLI support needed */
154 #endif
155 
156 /* wrapper around request_init() */
157 extern int hosts_ctl(const char *, const char *, const char *, const char *);
158 
159 /* access control */
160 extern int hosts_access(struct request_info *);
161 
162 /* execute shell command */
163 extern void shell_cmd(char *);
164 
165 /* do %<char> expansion */
166 extern char *percent_x(char *, int, char *, struct request_info *);
167 
168 /* client name from RFC 931 daemon */
169 extern void rfc931(struct sockaddr_gen *, struct sockaddr_gen *, char *);
170 
171 /* clean up and exit */
172 extern void clean_exit(struct request_info *);
173 
174 /* clean up and exit */
175 extern void refuse(struct request_info *);
176 
177 /* fgets() on steroids */
178 extern char *xgets(char *, int, __FILE *);
179 
180 /* strchr() and split */
181 extern char *split_at(char *, int);
182 
183 /* restricted inet_addr() */
184 extern unsigned long dot_quad_addr(char *);
185 
186 /* IP4/IP6 inet_addr (restricted) */
187 extern int numeric_addr(char *, union gen_addr *, int *, int *);
188 
189 /* IP4/IP6 gethostbyname */
190 extern struct hostent *tcpd_gethostbyname(char *, int);
191 
192 /* skip over colons in IPv6 addrs */
193 #ifdef HAVE_IPV6
194 extern char *skip_ipv6_addrs(char *);
195 #else
196 #define	skip_ipv6_addrs(x)	x
197 #endif
198 
199 /* Global variables. */
200 
201 extern int allow_severity;		/* for connection logging */
202 extern int deny_severity;		/* for connection logging */
203 extern char *hosts_allow_table;		/* for verification mode redirection */
204 extern char *hosts_deny_table;		/* for verification mode redirection */
205 extern int hosts_access_verbose;	/* for verbose matching mode */
206 extern int rfc931_timeout;		/* user lookup timeout */
207 extern int resident;			/* > 0 if resident process */
208 
209 /*
210  * Routines for controlled initialization and update of request structure
211  * attributes. Each attribute has its own key.
212  */
213 
214 extern struct request_info *request_init(struct request_info *, ...);
215 extern struct request_info *request_set(struct request_info *, ...);
216 
217 #define	RQ_FILE		1		/* file descriptor */
218 #define	RQ_DAEMON	2		/* server process (argv[0]) */
219 #define	RQ_USER		3		/* client user name */
220 #define	RQ_CLIENT_NAME	4		/* client host name */
221 #define	RQ_CLIENT_ADDR	5		/* client host address */
222 #define	RQ_CLIENT_SIN	6		/* client endpoint (internal) */
223 #define	RQ_SERVER_NAME	7		/* server host name */
224 #define	RQ_SERVER_ADDR	8		/* server host address */
225 #define	RQ_SERVER_SIN	9		/* server endpoint (internal) */
226 
227 /*
228  * Routines for delayed evaluation of request attributes. Each attribute
229  * type has its own access method. The trivial ones are implemented by
230  * macros. The other ones are wrappers around the transport-specific host
231  * name, address, and client user lookup methods. The request_info and
232  * host_info structures serve as caches for the lookup results.
233  */
234 
235 extern char *eval_user();		/* client user */
236 extern char *eval_hostname();		/* printable hostname */
237 extern char *eval_hostaddr();		/* printable host address */
238 extern char *eval_hostinfo();		/* host name or address */
239 extern char *eval_client();		/* whatever is available */
240 extern char *eval_server();		/* whatever is available */
241 #define	eval_daemon(r)	((r)->daemon)	/* daemon process name */
242 #define	eval_pid(r)	((r)->pid)	/* process id */
243 
244 /* Socket-specific methods, including DNS hostname lookups. */
245 
246 extern void sock_host();		/* look up endpoint addresses */
247 extern void sock_hostname();		/* translate address to hostname */
248 extern void sock_hostaddr();		/* address to printable address */
249 #define	sock_methods(r) \
250 	{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
251 
252 /* The System V Transport-Level Interface (TLI) interface. */
253 
254 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
255 extern void tli_host();			/* look up endpoint addresses etc. */
256 #endif
257 
258 /*
259  * Problem reporting interface. Additional file/line context is reported
260  * when available. The jump buffer (tcpd_buf) is not declared here, or
261  * everyone would have to include <setjmp.h>.
262  */
263 
264 #ifdef __STDC__
265 extern void tcpd_warn(char *, ...);	/* report problem and proceed */
266 extern void tcpd_jump(char *, ...);	/* report problem and jump */
267 #else
268 extern void tcpd_warn();
269 extern void tcpd_jump();
270 #endif
271 
272 struct tcpd_context {
273     char   *file;			/* current file */
274     int	    line;			/* current line */
275 };
276 extern struct tcpd_context tcpd_context;
277 
278 /*
279  * While processing access control rules, error conditions are handled by
280  * jumping back into the hosts_access() routine. This is cleaner than
281  * checking the return value of each and every silly little function. The
282  * (-1) returns are here because zero is already taken by longjmp().
283  */
284 
285 #define	AC_PERMIT	1		/* permit access */
286 #define	AC_DENY		(-1)		/* deny_access */
287 #define	AC_ERROR	AC_DENY		/* XXX */
288 
289 /*
290  * In verification mode an option function should just say what it would do,
291  * instead of really doing it. An option function that would not return
292  * should clear the dry_run flag to inform the caller of this unusual
293  * behavior.
294  */
295 
296 extern void process_options();		/* execute options */
297 extern int dry_run;			/* verification flag */
298 
299 /* Bug workarounds. */
300 
301 #ifdef INET_ADDR_BUG			/* inet_addr() returns struct */
302 #define	inet_addr fix_inet_addr
303 extern long fix_inet_addr();
304 #endif
305 
306 #ifdef BROKEN_FGETS			/* partial reads from sockets */
307 #define	fgets fix_fgets
308 extern char *fix_fgets();
309 #endif
310 
311 #ifdef RECVFROM_BUG			/* no address family info */
312 #define	recvfrom fix_recvfrom
313 extern int fix_recvfrom();
314 #endif
315 
316 #ifdef GETPEERNAME_BUG			/* claims success with UDP */
317 #define	getpeername fix_getpeername
318 extern int fix_getpeername();
319 #endif
320 
321 #ifdef SOLARIS_24_GETHOSTBYNAME_BUG	/* lists addresses as aliases */
322 #define	gethostbyname fix_gethostbyname
323 extern struct hostent *fix_gethostbyname();
324 #endif
325 
326 #ifdef USE_STRSEP			/* libc calls strtok() */
327 #define	strtok	fix_strtok
328 extern char *fix_strtok();
329 #endif
330 
331 #ifdef LIBC_CALLS_STRTOK		/* libc calls strtok() */
332 #define	strtok	my_strtok
333 extern char *my_strtok();
334 #endif
335 
336 #endif /* _TCPD_H */
337