lib/libwrap/tcpd.h

   1 /*      $NetBSD: tcpd.h,v 1.11 2001/03/27 22:46:55 kleink 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)                       /* datagram sink function or 0 */
  33                 __P((int));
  34     void  (*hostname)                   /* address to printable hostname */
  35                 __P((struct host_info *));
  36     void  (*hostaddr)                   /* address to printable address */
  37                 __P((struct host_info *));
  38     void  (*cleanup)                    /* cleanup function or 0 */
  39                 __P((void));
  40     struct netconfig *config;           /* netdir handle */
  41 };
  42
  43 /* Common string operations. Less clutter should be more readable. */
  44
  45 #define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
  46
  47 #define STRN_EQ(x,y,l)  (strncasecmp((x),(y),(l)) == 0)
  48 #define STRN_NE(x,y,l)  (strncasecmp((x),(y),(l)) != 0)
  49 #define STR_EQ(x,y)     (strcasecmp((x),(y)) == 0)
  50 #define STR_NE(x,y)     (strcasecmp((x),(y)) != 0)
  51
  52  /*
  53   * Initially, all above strings have the empty value. Information that
  54   * cannot be determined at runtime is set to "unknown", so that we can
  55   * distinguish between `unavailable' and `not yet looked up'. A hostname
  56   * that we do not believe in is set to "paranoid".
  57   */
  58
  59 #define STRING_UNKNOWN  "unknown"       /* lookup failed */
  60 #define STRING_PARANOID "paranoid"      /* hostname conflict */
  61
  62 __BEGIN_DECLS
  63 extern char unknown[];
  64 extern char paranoid[];
  65 __END_DECLS
  66
  67 #define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
  68
  69 #define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
  70
  71 /* Global functions. */
  72
  73 __BEGIN_DECLS
  74 #define fromhost sock_host              /* no TLI support needed */
  75
  76 extern int hosts_access                 /* access control */
  77                 __P((struct request_info *));
  78 extern int hosts_ctl                    /* limited interface to hosts_access */
  79                 __P((char *, char *, char *, char *));
  80 extern void shell_cmd                   /* execute shell command */
  81                 __P((char *));
  82 extern char *percent_x                  /* do %<char> expansion */
  83                 __P((char *, int, char *, struct request_info *));
  84 extern void rfc931                      /* client name from RFC 931 daemon */
  85                 __P((struct sockaddr *, struct sockaddr *, char *));
  86 extern void clean_exit                  /* clean up and exit */
  87                 __P((struct request_info *));
  88 extern void refuse                      /* clean up and exit */
  89                 __P((struct request_info *));
  90 extern char *xgets                      /* fgets() on steroids */
  91                 __P((char *, int, FILE *));
  92 extern char *split_at                   /* strchr() and split */
  93                 __P((char *, int));
  94 extern int dot_quad_addr        /* restricted inet_aton() */
  95                 __P((char *, unsigned long *));
  96
  97 /* Global variables. */
  98
  99 extern int allow_severity;              /* for connection logging */
 100 extern int deny_severity;               /* for connection logging */
 101 extern char *hosts_allow_table;         /* for verification mode redirection */
 102 extern char *hosts_deny_table;          /* for verification mode redirection */
 103 extern int hosts_access_verbose;        /* for verbose matching mode */
 104 extern int rfc931_timeout;              /* user lookup timeout */
 105 extern int resident;                    /* > 0 if resident process */
 106
 107  /*
 108   * Routines for controlled initialization and update of request structure
 109   * attributes. Each attribute has its own key.
 110   */
 111
 112 extern struct request_info *request_init        /* initialize request */
 113                 __P((struct request_info *,...));
 114 extern struct request_info *request_set         /* update request structure */
 115                 __P((struct request_info *,...));
 116
 117 #define RQ_FILE         1               /* file descriptor */
 118 #define RQ_DAEMON       2               /* server process (argv[0]) */
 119 #define RQ_USER         3               /* client user name */
 120 #define RQ_CLIENT_NAME  4               /* client host name */
 121 #define RQ_CLIENT_ADDR  5               /* client host address */
 122 #define RQ_CLIENT_SIN   6               /* client endpoint (internal) */
 123 #define RQ_SERVER_NAME  7               /* server host name */
 124 #define RQ_SERVER_ADDR  8               /* server host address */
 125 #define RQ_SERVER_SIN   9               /* server endpoint (internal) */
 126
 127  /*
 128   * Routines for delayed evaluation of request attributes. Each attribute
 129   * type has its own access method. The trivial ones are implemented by
 130   * macros. The other ones are wrappers around the transport-specific host
 131   * name, address, and client user lookup methods. The request_info and
 132   * host_info structures serve as caches for the lookup results.
 133   */
 134
 135 extern char *eval_user                  /* client user */
 136                 __P((struct request_info *));
 137 extern char *eval_hostname              /* printable hostname */
 138                 __P((struct host_info *));
 139 extern char *eval_hostaddr              /* printable host address */
 140                 __P((struct host_info *));
 141 extern char *eval_hostinfo              /* host name or address */
 142                 __P((struct host_info *));
 143 extern char *eval_client                /* whatever is available */
 144                 __P((struct request_info *));
 145 extern char *eval_server                /* whatever is available */
 146                 __P((struct request_info *));
 147 #define eval_daemon(r)  ((r)->daemon)   /* daemon process name */
 148 #define eval_pid(r)     ((r)->pid)      /* process id */
 149
 150 /* Socket-specific methods, including DNS hostname lookups. */
 151
 152 extern void sock_host                   /* look up endpoint addresses */
 153                 __P((struct request_info *));
 154 extern void sock_hostname               /* translate address to hostname */
 155                 __P((struct host_info *));
 156 extern void sock_hostaddr               /* address to printable address */
 157                 __P((struct host_info *));
 158 #define sock_methods(r) \
 159         { (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
 160
 161 /* The System V Transport-Level Interface (TLI) interface. */
 162
 163 #if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
 164 extern void tli_host                    /* look up endpoint addresses etc. */
 165                 __P((struct request_info *));
 166 #endif
 167
 168  /*
 169   * Problem reporting interface. Additional file/line context is reported
 170   * when available. The jump buffer (tcpd_buf) is not declared here, or
 171   * everyone would have to include <setjmp.h>.
 172   */
 173
 174 extern void tcpd_warn                   /* report problem and proceed */
 175                 __P((char *, ...))
 176         __attribute__((__format__(__printf__, 1, 2)));
 177 extern void tcpd_jump                   /* report problem and jump */
 178                 __P((char *, ...))
 179         __attribute__((__format__(__printf__, 1, 2)));
 180 __END_DECLS
 181
 182 struct tcpd_context {
 183     char   *file;                       /* current file */
 184     int     line;                       /* current line */
 185 };
 186 __BEGIN_DECLS
 187 extern struct tcpd_context tcpd_context;
 188 __END_DECLS
 189
 190  /*
 191   * While processing access control rules, error conditions are handled by
 192   * jumping back into the hosts_access() routine. This is cleaner than
 193   * checking the return value of each and every silly little function. The
 194   * (-1) returns are here because zero is already taken by longjmp().
 195   */
 196
 197 #define AC_PERMIT       1               /* permit access */
 198 #define AC_DENY         (-1)            /* deny_access */
 199 #define AC_ERROR        AC_DENY         /* XXX */
 200
 201  /*
 202   * In verification mode an option function should just say what it would do,
 203   * instead of really doing it. An option function that would not return
 204   * should clear the dry_run flag to inform the caller of this unusual
 205   * behavior.
 206   */
 207
 208 __BEGIN_DECLS
 209 extern void process_options             /* execute options */
 210                 __P((char *, struct request_info *));
 211 extern int dry_run;                     /* verification flag */
 212 extern void fix_options                 /* get rid of IP-level socket options */
 213                 __P((struct request_info *));
 214 __END_DECLS