xref: /freebsd/contrib/tcp_wrappers/tcpd.h (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1  /*
2   * @(#) tcpd.h 1.5 96/03/19 16:22:24
3   *
4   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
5   *
6   * $FreeBSD$
7   */
8 
9 #ifdef INET6
10 #define	TCPD_SOCKADDR struct sockaddr
11 #else
12 #define	TCPD_SOCKADDR struct sockaddr_in
13 #endif
14 
15 #ifndef _STDFILE_DECLARED
16 #define _STDFILE_DECLARED
17 typedef struct __sFILE FILE;
18 #endif
19 
20 /* Structure to describe one communications endpoint. */
21 
22 #define	STRING_LENGTH	128		/* hosts, users, processes */
23 
24 struct host_info {
25     char    name[STRING_LENGTH];	/* access via eval_hostname(host) */
26     char    addr[STRING_LENGTH];	/* access via eval_hostaddr(host) */
27     TCPD_SOCKADDR *sin;			/* socket address or 0 */
28     struct t_unitdata *unit;		/* TLI transport address or 0 */
29     struct request_info *request;	/* for shared information */
30 };
31 
32 /* Structure to describe what we know about a service request. */
33 
34 struct request_info {
35     int     fd;				/* socket handle */
36     char    user[STRING_LENGTH];	/* access via eval_user(request) */
37     char    daemon[STRING_LENGTH];	/* access via eval_daemon(request) */
38     char    pid[10];			/* access via eval_pid(request) */
39     struct host_info client[1];		/* client endpoint info */
40     struct host_info server[1];		/* server endpoint info */
41     void  (*sink) (int);		/* datagram sink function or 0 */
42     void  (*hostname) (struct host_info *); /* address to printable hostname */
43     void  (*hostaddr) (struct host_info *); /* address to printable address */
44     void  (*cleanup) (struct request_info *); /* cleanup function or 0 */
45     struct netconfig *config;		/* netdir handle */
46 };
47 
48 /* Common string operations. Less clutter should be more readable. */
49 
50 #define	STRN_CPY(d,s,l)	{ strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
51 
52 #define	STRN_EQ(x,y,l)	(strncasecmp((x),(y),(l)) == 0)
53 #define	STRN_NE(x,y,l)	(strncasecmp((x),(y),(l)) != 0)
54 #define	STR_EQ(x,y)	(strcasecmp((x),(y)) == 0)
55 #define	STR_NE(x,y)	(strcasecmp((x),(y)) != 0)
56 
57  /*
58   * Initially, all above strings have the empty value. Information that
59   * cannot be determined at runtime is set to "unknown", so that we can
60   * distinguish between `unavailable' and `not yet looked up'. A hostname
61   * that we do not believe in is set to "paranoid".
62   */
63 
64 #define	STRING_UNKNOWN	"unknown"	/* lookup failed */
65 #define	STRING_PARANOID	"paranoid"	/* hostname conflict */
66 
67 extern char unknown[];
68 extern char paranoid[];
69 
70 #define	HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
71 
72 #define	NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
73 
74 /* Global functions. */
75 
76 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
77 void fromhost(struct request_info *);	/* get/validate client host info */
78 #else
79 #define	fromhost sock_host		/* no TLI support needed */
80 #endif
81 
82 int hosts_access(struct request_info *);			/* access control */
83 int hosts_ctl(char *, char *, char *, char *);			/* wrapper around request_init() */
84 void shell_cmd(char *);						/* execute shell command */
85 char *percent_x(char *, int, char *, struct request_info *);	/* do %<char> expansion */
86 void rfc931(TCPD_SOCKADDR *, TCPD_SOCKADDR *, char *);		/* client name from RFC 931 daemon */
87 void clean_exit(struct request_info *);				/* clean up and exit */
88 void refuse(struct request_info *);				/* clean up and exit */
89 char *xgets(char *, int, FILE *);				/* fgets() on steroids */
90 
91 char *split_at(char *, int);					/* strchr() and split */
92 unsigned long dot_quad_addr(char *);				/* restricted inet_addr() */
93 
94 /* Global variables. */
95 
96 extern int allow_severity;		/* for connection logging */
97 extern int deny_severity;		/* for connection logging */
98 extern char *hosts_allow_table;		/* for verification mode redirection */
99 extern char *hosts_deny_table;		/* for verification mode redirection */
100 extern int hosts_access_verbose;	/* for verbose matching mode */
101 extern int rfc931_timeout;		/* user lookup timeout */
102 extern int resident;			/* > 0 if resident process */
103 
104  /*
105   * Routines for controlled initialization and update of request structure
106   * attributes. Each attribute has its own key.
107   */
108 
109 struct request_info *request_init(struct request_info *,...);	/* initialize request */
110 struct request_info *request_set(struct request_info *,...);	/* update request structure */
111 
112 #define	RQ_FILE		1		/* file descriptor */
113 #define	RQ_DAEMON	2		/* server process (argv[0]) */
114 #define	RQ_USER		3		/* client user name */
115 #define	RQ_CLIENT_NAME	4		/* client host name */
116 #define	RQ_CLIENT_ADDR	5		/* client host address */
117 #define	RQ_CLIENT_SIN	6		/* client endpoint (internal) */
118 #define	RQ_SERVER_NAME	7		/* server host name */
119 #define	RQ_SERVER_ADDR	8		/* server host address */
120 #define	RQ_SERVER_SIN	9		/* server endpoint (internal) */
121 
122  /*
123   * Routines for delayed evaluation of request attributes. Each attribute
124   * type has its own access method. The trivial ones are implemented by
125   * macros. The other ones are wrappers around the transport-specific host
126   * name, address, and client user lookup methods. The request_info and
127   * host_info structures serve as caches for the lookup results.
128   */
129 
130 char *eval_user(struct request_info *);		/* client user */
131 char *eval_hostname(struct host_info *);	/* printable hostname */
132 char *eval_hostaddr(struct host_info *);	/* printable host address */
133 char *eval_hostinfo(struct host_info *);	/* host name or address */
134 char *eval_client(struct request_info *);	/* whatever is available */
135 char *eval_server(struct request_info *);	/* whatever is available */
136 #define	eval_daemon(r)	((r)->daemon)	/* daemon process name */
137 #define	eval_pid(r)	((r)->pid)	/* process id */
138 
139 /* Socket-specific methods, including DNS hostname lookups. */
140 
141 void sock_host(struct request_info *);		/* look up endpoint addresses */
142 void sock_hostname(struct host_info *);		/* translate address to hostname */
143 void sock_hostaddr(struct host_info *);		/* address to printable address */
144 #define	sock_methods(r) \
145 	{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
146 
147 /* The System V Transport-Level Interface (TLI) interface. */
148 
149 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
150 void tli_host(struct request_info *);		/* look up endpoint addresses etc. */
151 #endif
152 
153  /*
154   * Problem reporting interface. Additional file/line context is reported
155   * when available. The jump buffer (tcpd_buf) is not declared here, or
156   * everyone would have to include <setjmp.h>.
157   */
158 
159 void tcpd_warn(char *, ...);		/* report problem and proceed */
160 void tcpd_jump(char *, ...);		/* report problem and jump */
161 
162 struct tcpd_context {
163     char   *file;			/* current file */
164     int     line;			/* current line */
165 };
166 extern struct tcpd_context tcpd_context;
167 
168  /*
169   * While processing access control rules, error conditions are handled by
170   * jumping back into the hosts_access() routine. This is cleaner than
171   * checking the return value of each and every silly little function. The
172   * (-1) returns are here because zero is already taken by longjmp().
173   */
174 
175 #define	AC_PERMIT	1		/* permit access */
176 #define	AC_DENY		(-1)		/* deny_access */
177 #define	AC_ERROR	AC_DENY		/* XXX */
178 
179  /*
180   * In verification mode an option function should just say what it would do,
181   * instead of really doing it. An option function that would not return
182   * should clear the dry_run flag to inform the caller of this unusual
183   * behavior.
184   */
185 
186 void process_options(char *, struct request_info *);	/* execute options */
187 extern int dry_run;					/* verification flag */
188 
189 /* Bug workarounds. */
190 
191 #ifdef INET_ADDR_BUG			/* inet_addr() returns struct */
192 #define	inet_addr fix_inet_addr
193 long fix_inet_addr(char *);
194 #endif
195 
196 #ifdef BROKEN_FGETS			/* partial reads from sockets */
197 #define	fgets fix_fgets
198 char *fix_fgets(char *, int, FILE *);
199 #endif
200 
201 #ifdef RECVFROM_BUG			/* no address family info */
202 #define	recvfrom fix_recvfrom
203 int fix_recvfrom(int, char *, int, int, struct sockaddr *, int *);
204 #endif
205 
206 #ifdef GETPEERNAME_BUG			/* claims success with UDP */
207 #define	getpeername fix_getpeername
208 int fix_getpeername(int, struct sockaddr *, int *);
209 #endif
210 
211 #ifdef SOLARIS_24_GETHOSTBYNAME_BUG	/* lists addresses as aliases */
212 #define	gethostbyname fix_gethostbyname
213 struct hostent *fix_gethostbyname(char *);
214 #endif
215 
216 #ifdef USE_STRSEP			/* libc calls strtok() */
217 #define	strtok	fix_strtok
218 char *fix_strtok(char *, char *);
219 #endif
220 
221 #ifdef LIBC_CALLS_STRTOK		/* libc calls strtok() */
222 #define	strtok	my_strtok
223 char *my_strtok(char *, char *);
224 #endif
225