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tcpd.h revision 1.9
      1 /*	$NetBSD: tcpd.h,v 1.9 2000/02/05 19:14:57 danw 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 <stdio.h>
      9 
     10 /* Structure to describe one communications endpoint. */
     11 
     12 #define STRING_LENGTH	128		/* hosts, users, processes */
     13 
     14 struct host_info {
     15     char    name[STRING_LENGTH];	/* access via eval_hostname(host) */
     16     char    addr[STRING_LENGTH];	/* access via eval_hostaddr(host) */
     17     struct sockaddr *sin;		/* socket address or 0 */
     18     struct t_unitdata *unit;		/* TLI transport address or 0 */
     19     struct request_info *request;	/* for shared information */
     20 };
     21 
     22 /* Structure to describe what we know about a service request. */
     23 
     24 struct request_info {
     25     int     fd;				/* socket handle */
     26     char    user[STRING_LENGTH];	/* access via eval_user(request) */
     27     char    daemon[STRING_LENGTH];	/* access via eval_daemon(request) */
     28     char    pid[10];			/* access via eval_pid(request) */
     29     struct host_info client[1];		/* client endpoint info */
     30     struct host_info server[1];		/* server endpoint info */
     31     void  (*sink)			/* datagram sink function or 0 */
     32 		__P((int));
     33     void  (*hostname)			/* address to printable hostname */
     34 		__P((struct host_info *));
     35     void  (*hostaddr)			/* address to printable address */
     36 		__P((struct host_info *));
     37     void  (*cleanup)			/* cleanup function or 0 */
     38 		__P((void));
     39     struct netconfig *config;		/* netdir handle */
     40 };
     41 
     42 /* Common string operations. Less clutter should be more readable. */
     43 
     44 #define STRN_CPY(d,s,l)	{ strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
     45 
     46 #define STRN_EQ(x,y,l)	(strncasecmp((x),(y),(l)) == 0)
     47 #define STRN_NE(x,y,l)	(strncasecmp((x),(y),(l)) != 0)
     48 #define STR_EQ(x,y)	(strcasecmp((x),(y)) == 0)
     49 #define STR_NE(x,y)	(strcasecmp((x),(y)) != 0)
     50 
     51  /*
     52   * Initially, all above strings have the empty value. Information that
     53   * cannot be determined at runtime is set to "unknown", so that we can
     54   * distinguish between `unavailable' and `not yet looked up'. A hostname
     55   * that we do not believe in is set to "paranoid".
     56   */
     57 
     58 #define STRING_UNKNOWN	"unknown"	/* lookup failed */
     59 #define STRING_PARANOID	"paranoid"	/* hostname conflict */
     60 
     61 extern char unknown[];
     62 extern char paranoid[];
     63 
     64 #define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
     65 
     66 #define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
     67 
     68 /* Global functions. */
     69 
     70 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
     71 extern void fromhost			/* get/validate client host info */
     72 		__P((struct request_info *));
     73 #else
     74 #define fromhost sock_host		/* no TLI support needed */
     75 #endif
     76 
     77 extern int hosts_access			/* access control */
     78 		__P((struct request_info *));
     79 extern int hosts_ctl			/* limited interface to hosts_access */
     80 		__P((char *, char *, char *, char *));
     81 extern void shell_cmd			/* execute shell command */
     82 		__P((char *));
     83 extern char *percent_x			/* do %<char> expansion */
     84 		__P((char *, int, char *, struct request_info *));
     85 extern void rfc931			/* client name from RFC 931 daemon */
     86 		__P((struct sockaddr *, struct sockaddr *, char *));
     87 extern void clean_exit			/* clean up and exit */
     88 		__P((struct request_info *));
     89 extern void refuse			/* clean up and exit */
     90 		__P((struct request_info *));
     91 extern char *xgets			/* fgets() on steroids */
     92 		__P((char *, int, FILE *));
     93 extern char *split_at			/* strchr() and split */
     94 		__P((char *, int));
     95 extern int dot_quad_addr	/* restricted inet_aton() */
     96 		__P((char *, unsigned long *));
     97 
     98 /* Global variables. */
     99 
    100 extern int allow_severity;		/* for connection logging */
    101 extern int deny_severity;		/* for connection logging */
    102 extern char *hosts_allow_table;		/* for verification mode redirection */
    103 extern char *hosts_deny_table;		/* for verification mode redirection */
    104 extern int hosts_access_verbose;	/* for verbose matching mode */
    105 extern int rfc931_timeout;		/* user lookup timeout */
    106 extern int resident;			/* > 0 if resident process */
    107 
    108  /*
    109   * Routines for controlled initialization and update of request structure
    110   * attributes. Each attribute has its own key.
    111   */
    112 
    113 extern struct request_info *request_init	/* initialize request */
    114 		__P((struct request_info *,...));
    115 extern struct request_info *request_set		/* update request structure */
    116 		__P((struct request_info *,...));
    117 
    118 #define RQ_FILE		1		/* file descriptor */
    119 #define RQ_DAEMON	2		/* server process (argv[0]) */
    120 #define RQ_USER		3		/* client user name */
    121 #define RQ_CLIENT_NAME	4		/* client host name */
    122 #define RQ_CLIENT_ADDR	5		/* client host address */
    123 #define RQ_CLIENT_SIN	6		/* client endpoint (internal) */
    124 #define RQ_SERVER_NAME	7		/* server host name */
    125 #define RQ_SERVER_ADDR	8		/* server host address */
    126 #define RQ_SERVER_SIN	9		/* server endpoint (internal) */
    127 
    128  /*
    129   * Routines for delayed evaluation of request attributes. Each attribute
    130   * type has its own access method. The trivial ones are implemented by
    131   * macros. The other ones are wrappers around the transport-specific host
    132   * name, address, and client user lookup methods. The request_info and
    133   * host_info structures serve as caches for the lookup results.
    134   */
    135 
    136 extern char *eval_user			/* client user */
    137 		__P((struct request_info *));
    138 extern char *eval_hostname		/* printable hostname */
    139 		__P((struct host_info *));
    140 extern char *eval_hostaddr		/* printable host address */
    141 		__P((struct host_info *));
    142 extern char *eval_hostinfo		/* host name or address */
    143 		__P((struct host_info *));
    144 extern char *eval_client		/* whatever is available */
    145 		__P((struct request_info *));
    146 extern char *eval_server		/* whatever is available */
    147 		__P((struct request_info *));
    148 #define eval_daemon(r)	((r)->daemon)	/* daemon process name */
    149 #define eval_pid(r)	((r)->pid)	/* process id */
    150 
    151 /* Socket-specific methods, including DNS hostname lookups. */
    152 
    153 extern void sock_host			/* look up endpoint addresses */
    154 		__P((struct request_info *));
    155 extern void sock_hostname		/* translate address to hostname */
    156 		__P((struct host_info *));
    157 extern void sock_hostaddr		/* address to printable address */
    158 		__P((struct host_info *));
    159 #define sock_methods(r) \
    160 	{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
    161 
    162 /* The System V Transport-Level Interface (TLI) interface. */
    163 
    164 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
    165 extern void tli_host			/* look up endpoint addresses etc. */
    166 		__P((struct request_info *));
    167 #endif
    168 
    169  /*
    170   * Problem reporting interface. Additional file/line context is reported
    171   * when available. The jump buffer (tcpd_buf) is not declared here, or
    172   * everyone would have to include <setjmp.h>.
    173   */
    174 
    175 extern void tcpd_warn			/* report problem and proceed */
    176 		__P((char *, ...));
    177 extern void tcpd_jump			/* report problem and jump */
    178 		__P((char *, ...));
    179 
    180 struct tcpd_context {
    181     char   *file;			/* current file */
    182     int     line;			/* current line */
    183 };
    184 extern struct tcpd_context tcpd_context;
    185 
    186  /*
    187   * While processing access control rules, error conditions are handled by
    188   * jumping back into the hosts_access() routine. This is cleaner than
    189   * checking the return value of each and every silly little function. The
    190   * (-1) returns are here because zero is already taken by longjmp().
    191   */
    192 
    193 #define AC_PERMIT	1		/* permit access */
    194 #define AC_DENY		(-1)		/* deny_access */
    195 #define AC_ERROR	AC_DENY		/* XXX */
    196 
    197  /*
    198   * In verification mode an option function should just say what it would do,
    199   * instead of really doing it. An option function that would not return
    200   * should clear the dry_run flag to inform the caller of this unusual
    201   * behavior.
    202   */
    203 
    204 extern void process_options		/* execute options */
    205 		__P((char *, struct request_info *));
    206 extern int dry_run;			/* verification flag */
    207 extern void fix_options			/* get rid of IP-level socket options */
    208 		__P((struct request_info *));
    209 /* Bug workarounds. */
    210 
    211 #ifdef INET_ADDR_BUG			/* inet_addr() returns struct */
    212 #define inet_addr fix_inet_addr
    213 extern long fix_inet_addr __P((char *));
    214 #endif
    215 
    216 #ifdef BROKEN_FGETS			/* partial reads from sockets */
    217 #define fgets fix_fgets
    218 extern char *fix_fgets __P((char *, int, FILE *));
    219 #endif
    220 
    221 #ifdef RECVFROM_BUG			/* no address family info */
    222 #define recvfrom fix_recvfrom
    223 extern int fix_recvfrom __P((int, char *, int, int, struct sockaddr *, int *));
    224 #endif
    225 
    226 #ifdef GETPEERNAME_BUG			/* claims success with UDP */
    227 #include <sys/socket.h>			/* XXX serious hack! */
    228 #define getpeername fix_getpeername
    229 extern int fix_getpeername __P((int, struct sockaddr *, int *));
    230 #endif
    231 
    232 #ifdef SOLARIS_24_GETHOSTBYNAME_BUG	/* lists addresses as aliases */
    233 #define gethostbyname fix_gethostbyname
    234 extern struct hostent *fix_gethostbyname __P((char *));
    235 #endif
    236 
    237 #ifdef USE_STRSEP			/* libc calls strtok() */
    238 #define strtok	fix_strtok
    239 extern char *fix_strtok __P((char *, char *));
    240 #endif
    241 
    242 #ifdef LIBC_CALLS_STRTOK		/* libc calls strtok() */
    243 #define strtok	my_strtok
    244 extern char *my_strtok __P((char *, char *));
    245 #endif
    246