contrib/tcp_wrappers/tcpd.h

   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: src/contrib/tcp_wrappers/tcpd.h,v 1.2 2000/02/03 10:26:59 shin Exp $
   7   */
   8
   9 #ifndef _LIBWRAP_TCPD_H
  10 #define _LIBWRAP_TCPD_H
  11
  12 #include <sys/cdefs.h>
  13 #include <sys/socket.h>
  14 #include <stdio.h>
  15
  16 /* Structure to describe one communications endpoint. */
  17
  18 #define STRING_LENGTH   128             /* hosts, users, processes */
  19
  20 struct host_info {
  21     char    name[STRING_LENGTH];        /* access via eval_hostname(host) */
  22     char    addr[STRING_LENGTH];        /* access via eval_hostaddr(host) */
  23 #ifdef INET6
  24     struct sockaddr *sin;               /* socket address or 0 */
  25 #else
  26     struct sockaddr_in *sin;            /* socket address or 0 */
  27 #endif
  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)                   /* address to printable hostname */
  43           (struct host_info *);
  44     void  (*hostaddr)                   /* address to printable address */
  45           (struct host_info *);
  46     void  (*cleanup) (void);            /* cleanup function or 0 */
  47     struct netconfig *config;           /* netdir handle */
  48 };
  49
  50 /* Common string operations. Less clutter should be more readable. */
  51
  52 #define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
  53
  54 #define STRN_EQ(x,y,l)  (strncasecmp((x),(y),(l)) == 0)
  55 #define STRN_NE(x,y,l)  (strncasecmp((x),(y),(l)) != 0)
  56 #define STR_EQ(x,y)     (strcasecmp((x),(y)) == 0)
  57 #define STR_NE(x,y)     (strcasecmp((x),(y)) != 0)
  58
  59  /*
  60   * Initially, all above strings have the empty value. Information that
  61   * cannot be determined at runtime is set to "unknown", so that we can
  62   * distinguish between `unavailable' and `not yet looked up'. A hostname
  63   * that we do not believe in is set to "paranoid".
  64   */
  65
  66 #define STRING_UNKNOWN  "unknown"       /* lookup failed */
  67 #define STRING_PARANOID "paranoid"      /* hostname conflict */
  68
  69 __BEGIN_DECLS
  70 extern char unknown[];
  71 extern char paranoid[];
  72 __END_DECLS
  73
  74 #define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
  75
  76 #define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
  77
  78 /* Global functions. */
  79
  80 __BEGIN_DECLS
  81 #define fromhost sock_host
  82
  83 int             hosts_access(struct request_info *);/* access control */
  84 int             hosts_ctl(char *, char *, char *, char *);/* limited interface to the hosts_access() routine */
  85 void            shell_cmd(char *);              /* execute shell command */
  86 char            *percent_x(char *, int, char *, struct request_info *);/* do %<char> expansion */
  87 void            rfc931(struct sockaddr *, struct sockaddr *, char *);/* client name from RFC 931 daemon */
  88 void            clean_exit(struct request_info *);/* clean up and exit */
  89 void            refuse(struct request_info *);  /* clean up and exit */
  90 char            *xgets(char *, int, FILE *);    /* fgets() on steroids */
  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  /*
 148   * Problem reporting interface. Additional file/line context is reported
 149   * when available. The jump buffer (tcpd_buf) is not declared here, or
 150   * everyone would have to include <setjmp.h>.
 151   */
 152
 153 void    tcpd_warn(const char *, ...) __printflike(1, 2);/* report problem and proceed */
 154 void    tcpd_jump(const char *, ...) __printflike(1, 2) __dead2;/* report problem and jump */
 155 __END_DECLS
 156
 157 struct tcpd_context {
 158     char   *file;                       /* current file */
 159     int     line;                       /* current line */
 160 };
 161 __BEGIN_DECLS
 162 extern struct tcpd_context tcpd_context;
 163 __END_DECLS
 164
 165  /*
 166   * While processing access control rules, error conditions are handled by
 167   * jumping back into the hosts_access() routine. This is cleaner than
 168   * checking the return value of each and every silly little function. The
 169   * (-1) returns are here because zero is already taken by longjmp().
 170   */
 171
 172 #define AC_PERMIT       1               /* permit access */
 173 #define AC_DENY         (-1)            /* deny_access */
 174 #define AC_ERROR        AC_DENY         /* XXX */
 175
 176 __BEGIN_DECLS
 177  /*
 178   * In verification mode an option function should just say what it would do,
 179   * instead of really doing it. An option function that would not return
 180   * should clear the dry_run flag to inform the caller of this unusual
 181   * behavior.
 182   */
 183
 184 void    process_options(char *, struct request_info *); /* execute options */
 185 void    fix_options(struct request_info *);             /* get rid of IP-level socket options */
 186
 187 extern int dry_run;                     /* verification flag */
 188 __END_DECLS
 189
 190 #endif  /* !_LIBWRAP_TCPD_H */