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      1 /*	$NetBSD: tcpd.h,v 1.15 2015/10/14 15:54:21 christos Exp $	*/
      2  /*
      3   * @(#) tcpd.h 1.5 96/03/19 16:22:24
      4   *
      5   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
      6   */
      7 
      8 #include <sys/cdefs.h>
      9 #include <stdio.h>
     10 
     11 /* Structure to describe one communications endpoint. */
     12 
     13 #define STRING_LENGTH	128		/* hosts, users, processes */
     14 
     15 struct host_info {
     16     char    name[STRING_LENGTH];	/* access via eval_hostname(host) */
     17     char    addr[STRING_LENGTH];	/* access via eval_hostaddr(host) */
     18     struct sockaddr *sin;		/* socket address or 0 */
     19     struct t_unitdata *unit;		/* TLI transport address or 0 */
     20     struct request_info *request;	/* for shared information */
     21 };
     22 
     23 /* Structure to describe what we know about a service request. */
     24 
     25 struct request_info {
     26     int     fd;				/* socket handle */
     27     char    user[STRING_LENGTH];	/* access via eval_user(request) */
     28     char    daemon[STRING_LENGTH];	/* access via eval_daemon(request) */
     29     char    pid[10];			/* access via eval_pid(request) */
     30     struct host_info client[1];		/* client endpoint info */
     31     struct host_info server[1];		/* server endpoint info */
     32     void (*sink)(int);			/* datagram sink function or 0 */
     33     void (*hostname)(struct host_info *); /* address to printable hostname */
     34     void (*hostaddr)(struct host_info *); /* address to printable address */
     35     void (*cleanup)(void);		/* cleanup function or 0 */
     36     struct netconfig *config;		/* netdir handle */
     37 };
     38 
     39 /* Common string operations. Less clutter should be more readable. */
     40 
     41 #define STRN_CPY(d,s,l)	{ strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
     42 
     43 #define STRN_EQ(x,y,l)	(strncasecmp((x),(y),(l)) == 0)
     44 #define STRN_NE(x,y,l)	(strncasecmp((x),(y),(l)) != 0)
     45 #define STR_EQ(x,y)	(strcasecmp((x),(y)) == 0)
     46 #define STR_NE(x,y)	(strcasecmp((x),(y)) != 0)
     47 
     48  /*
     49   * Initially, all above strings have the empty value. Information that
     50   * cannot be determined at runtime is set to "unknown", so that we can
     51   * distinguish between `unavailable' and `not yet looked up'. A hostname
     52   * that we do not believe in is set to "paranoid".
     53   */
     54 
     55 #define STRING_UNKNOWN	"unknown"	/* lookup failed */
     56 #define STRING_PARANOID	"paranoid"	/* hostname conflict */
     57 
     58 __BEGIN_DECLS
     59 extern char unknown[];
     60 extern char paranoid[];
     61 __END_DECLS
     62 
     63 #define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
     64 
     65 #define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
     66 
     67 /* Global functions. */
     68 
     69 __BEGIN_DECLS
     70 #define fromhost sock_host		/* no TLI support needed */
     71 
     72 extern int hosts_access			/* access control */
     73 		(struct request_info *);
     74 extern int hosts_ctl			/* limited interface to hosts_access */
     75 		(char *, char *, char *, char *);
     76 extern void shell_cmd			/* execute shell command */
     77 		(char *);
     78 extern char *percent_x			/* do %<char> expansion */
     79 		(char *, int, char *, struct request_info *);
     80 extern void rfc931			/* client name from RFC 931 daemon */
     81 		(struct sockaddr *, struct sockaddr *, char *);
     82 __dead extern void clean_exit		/* clean up and exit */
     83 		(struct request_info *);
     84 __dead extern void refuse		/* clean up and exit */
     85 		(struct request_info *);
     86 extern char *xgets			/* fgets() on steroids */
     87 		(char *, int, FILE *);
     88 extern char *split_at			/* strchr() and split */
     89 		(char *, int);
     90 extern int dot_quad_addr	/* restricted inet_aton() */
     91 		(char *, unsigned long *);
     92 
     93 /* Global variables. */
     94 
     95 extern int allow_severity;		/* for connection logging */
     96 extern int deny_severity;		/* for connection logging */
     97 extern const char *hosts_allow_table;	/* for verification mode redirection */
     98 extern const char *hosts_deny_table;	/* for verification mode redirection */
     99 extern int hosts_access_verbose;	/* for verbose matching mode */
    100 extern int rfc931_timeout;		/* user lookup timeout */
    101 extern int resident;			/* > 0 if resident process */
    102 
    103  /*
    104   * Routines for controlled initialization and update of request structure
    105   * attributes. Each attribute has its own key.
    106   */
    107 
    108 extern struct request_info *request_init	/* initialize request */
    109 		(struct request_info *,...);
    110 extern struct request_info *request_set		/* update request structure */
    111 		(struct request_info *,...);
    112 
    113 #define RQ_FILE		1		/* file descriptor */
    114 #define RQ_DAEMON	2		/* server process (argv[0]) */
    115 #define RQ_USER		3		/* client user name */
    116 #define RQ_CLIENT_NAME	4		/* client host name */
    117 #define RQ_CLIENT_ADDR	5		/* client host address */
    118 #define RQ_CLIENT_SIN	6		/* client endpoint (internal) */
    119 #define RQ_SERVER_NAME	7		/* server host name */
    120 #define RQ_SERVER_ADDR	8		/* server host address */
    121 #define RQ_SERVER_SIN	9		/* server endpoint (internal) */
    122 
    123  /*
    124   * Routines for delayed evaluation of request attributes. Each attribute
    125   * type has its own access method. The trivial ones are implemented by
    126   * macros. The other ones are wrappers around the transport-specific host
    127   * name, address, and client user lookup methods. The request_info and
    128   * host_info structures serve as caches for the lookup results.
    129   */
    130 
    131 extern char *eval_user			/* client user */
    132 		(struct request_info *);
    133 extern char *eval_hostname		/* printable hostname */
    134 		(struct host_info *);
    135 extern char *eval_hostaddr		/* printable host address */
    136 		(struct host_info *);
    137 extern char *eval_hostinfo		/* host name or address */
    138 		(struct host_info *);
    139 extern char *eval_client		/* whatever is available */
    140 		(struct request_info *);
    141 extern char *eval_server		/* whatever is available */
    142 		(struct request_info *);
    143 #define eval_daemon(r)	((r)->daemon)	/* daemon process name */
    144 #define eval_pid(r)	((r)->pid)	/* process id */
    145 
    146 /* Socket-specific methods, including DNS hostname lookups. */
    147 
    148 extern void sock_host			/* look up endpoint addresses */
    149 		(struct request_info *);
    150 extern void sock_hostname		/* translate address to hostname */
    151 		(struct host_info *);
    152 extern void sock_hostaddr		/* address to printable address */
    153 		(struct host_info *);
    154 #define sock_methods(r) \
    155 	{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
    156 
    157 /* The System V Transport-Level Interface (TLI) interface. */
    158 
    159 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
    160 extern void tli_host			/* look up endpoint addresses etc. */
    161 		(struct request_info *);
    162 #endif
    163 
    164  /*
    165   * Problem reporting interface. Additional file/line context is reported
    166   * when available. The jump buffer (tcpd_buf) is not declared here, or
    167   * everyone would have to include <setjmp.h>.
    168   */
    169 
    170 /* Report problem and proceed */
    171 void tcpd_warn(const char *, ...) __sysloglike(1, 2);
    172 
    173 /* Report problem and jump */
    174 void tcpd_jump(const char *, ...) __dead __sysloglike(1, 2);
    175 __END_DECLS
    176 
    177 struct tcpd_context {
    178     const char *file;			/* current file */
    179     int     line;			/* current line */
    180 };
    181 __BEGIN_DECLS
    182 extern struct tcpd_context tcpd_context;
    183 __END_DECLS
    184 
    185  /*
    186   * While processing access control rules, error conditions are handled by
    187   * jumping back into the hosts_access() routine. This is cleaner than
    188   * checking the return value of each and every silly little function. The
    189   * (-1) returns are here because zero is already taken by longjmp().
    190   */
    191 
    192 #define AC_PERMIT	1		/* permit access */
    193 #define AC_DENY		(-1)		/* deny_access */
    194 #define AC_ERROR	AC_DENY		/* XXX */
    195 
    196  /*
    197   * In verification mode an option function should just say what it would do,
    198   * instead of really doing it. An option function that would not return
    199   * should clear the dry_run flag to inform the caller of this unusual
    200   * behavior.
    201   */
    202 
    203 __BEGIN_DECLS
    204 extern void process_options		/* execute options */
    205 		(char *, struct request_info *);
    206 extern int dry_run;			/* verification flag */
    207 extern void fix_options			/* get rid of IP-level socket options */
    208 		(struct request_info *);
    209 __END_DECLS
    210