lib/libwrap/tcpd.h

   1 /*      $NetBSD: tcpd.h,v 1.14 2012/03/22 22:59:43 joerg 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 *, ...) __printflike(1, 2);
 172
 173 /* Report problem and jump */
 174 void tcpd_jump(const char *, ...) __dead __printflike(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