freebsd-dev/contrib/tcp_wrappers/tcpd.h
Yoshinobu Inoue 8053080cbc Missing tcp_wrapper IPv6 support seemed to be a bug, so commit it.
Now when tcp_wrapper is enabled by inetd -wW,
  several accesses which should be permitted are refused only for IPv6,
  if hostname is used to decide the host to be allowed.
  IPv6 users will be just upset.

  About security related concern.
    -All extensions are wrapped by #ifdef INET6, so people can completely
     disable the extension by recompile libwrap without INET6 option.
    -Access via IPv6 is not enabled by default.
     People need to enable IPv6 access by changing /etc/inetd.conf at first,
     by adding tcp6 and/or tcp46 entries.
    -The base of patches are from KAME package and are actually daily used
     for more than a year in several Japanese IPv6 environments.
    -Patches are reviewed by markm.

Approved by: jkh

Submitted by: Hajimu UMEMOTO <ume@mahoroba.org>
Reviewed by: markm
Obtained from: KAME project
2000-02-03 10:27:03 +00:00

226 lines
7.8 KiB
C

/*
* @(#) tcpd.h 1.5 96/03/19 16:22:24
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*
* $FreeBSD$
*/
/* Structure to describe one communications endpoint. */
#define STRING_LENGTH 128 /* hosts, users, processes */
struct host_info {
char name[STRING_LENGTH]; /* access via eval_hostname(host) */
char addr[STRING_LENGTH]; /* access via eval_hostaddr(host) */
#ifdef INET6
struct sockaddr *sin; /* socket address or 0 */
#else
struct sockaddr_in *sin; /* socket address or 0 */
#endif
struct t_unitdata *unit; /* TLI transport address or 0 */
struct request_info *request; /* for shared information */
};
/* Structure to describe what we know about a service request. */
struct request_info {
int fd; /* socket handle */
char user[STRING_LENGTH]; /* access via eval_user(request) */
char daemon[STRING_LENGTH]; /* access via eval_daemon(request) */
char pid[10]; /* access via eval_pid(request) */
struct host_info client[1]; /* client endpoint info */
struct host_info server[1]; /* server endpoint info */
void (*sink) (); /* datagram sink function or 0 */
void (*hostname) (); /* address to printable hostname */
void (*hostaddr) (); /* address to printable address */
void (*cleanup) (); /* cleanup function or 0 */
struct netconfig *config; /* netdir handle */
};
/* Common string operations. Less clutter should be more readable. */
#define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
#define STRN_EQ(x,y,l) (strncasecmp((x),(y),(l)) == 0)
#define STRN_NE(x,y,l) (strncasecmp((x),(y),(l)) != 0)
#define STR_EQ(x,y) (strcasecmp((x),(y)) == 0)
#define STR_NE(x,y) (strcasecmp((x),(y)) != 0)
/*
* Initially, all above strings have the empty value. Information that
* cannot be determined at runtime is set to "unknown", so that we can
* distinguish between `unavailable' and `not yet looked up'. A hostname
* that we do not believe in is set to "paranoid".
*/
#define STRING_UNKNOWN "unknown" /* lookup failed */
#define STRING_PARANOID "paranoid" /* hostname conflict */
extern char unknown[];
extern char paranoid[];
#define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
#define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
/* Global functions. */
#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void fromhost(); /* get/validate client host info */
#else
#define fromhost sock_host /* no TLI support needed */
#endif
extern int hosts_access(); /* access control */
extern void shell_cmd(); /* execute shell command */
extern char *percent_x(); /* do %<char> expansion */
extern void rfc931(); /* client name from RFC 931 daemon */
extern void clean_exit(); /* clean up and exit */
extern void refuse(); /* clean up and exit */
extern char *xgets(); /* fgets() on steroids */
extern char *split_at(); /* strchr() and split */
extern unsigned long dot_quad_addr(); /* restricted inet_addr() */
/* Global variables. */
extern int allow_severity; /* for connection logging */
extern int deny_severity; /* for connection logging */
extern char *hosts_allow_table; /* for verification mode redirection */
extern char *hosts_deny_table; /* for verification mode redirection */
extern int hosts_access_verbose; /* for verbose matching mode */
extern int rfc931_timeout; /* user lookup timeout */
extern int resident; /* > 0 if resident process */
/*
* Routines for controlled initialization and update of request structure
* attributes. Each attribute has its own key.
*/
#ifdef __STDC__
extern struct request_info *request_init(struct request_info *,...);
extern struct request_info *request_set(struct request_info *,...);
#else
extern struct request_info *request_init(); /* initialize request */
extern struct request_info *request_set(); /* update request structure */
#endif
#define RQ_FILE 1 /* file descriptor */
#define RQ_DAEMON 2 /* server process (argv[0]) */
#define RQ_USER 3 /* client user name */
#define RQ_CLIENT_NAME 4 /* client host name */
#define RQ_CLIENT_ADDR 5 /* client host address */
#define RQ_CLIENT_SIN 6 /* client endpoint (internal) */
#define RQ_SERVER_NAME 7 /* server host name */
#define RQ_SERVER_ADDR 8 /* server host address */
#define RQ_SERVER_SIN 9 /* server endpoint (internal) */
/*
* Routines for delayed evaluation of request attributes. Each attribute
* type has its own access method. The trivial ones are implemented by
* macros. The other ones are wrappers around the transport-specific host
* name, address, and client user lookup methods. The request_info and
* host_info structures serve as caches for the lookup results.
*/
extern char *eval_user(); /* client user */
extern char *eval_hostname(); /* printable hostname */
extern char *eval_hostaddr(); /* printable host address */
extern char *eval_hostinfo(); /* host name or address */
extern char *eval_client(); /* whatever is available */
extern char *eval_server(); /* whatever is available */
#define eval_daemon(r) ((r)->daemon) /* daemon process name */
#define eval_pid(r) ((r)->pid) /* process id */
/* Socket-specific methods, including DNS hostname lookups. */
extern void sock_host(); /* look up endpoint addresses */
extern void sock_hostname(); /* translate address to hostname */
extern void sock_hostaddr(); /* address to printable address */
#define sock_methods(r) \
{ (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
/* The System V Transport-Level Interface (TLI) interface. */
#if defined(TLI) || defined(PTX) || defined(TLI_SEQUENT)
extern void tli_host(); /* look up endpoint addresses etc. */
#endif
/*
* Problem reporting interface. Additional file/line context is reported
* when available. The jump buffer (tcpd_buf) is not declared here, or
* everyone would have to include <setjmp.h>.
*/
#ifdef __STDC__
extern void tcpd_warn(char *, ...); /* report problem and proceed */
extern void tcpd_jump(char *, ...); /* report problem and jump */
#else
extern void tcpd_warn();
extern void tcpd_jump();
#endif
struct tcpd_context {
char *file; /* current file */
int line; /* current line */
};
extern struct tcpd_context tcpd_context;
/*
* While processing access control rules, error conditions are handled by
* jumping back into the hosts_access() routine. This is cleaner than
* checking the return value of each and every silly little function. The
* (-1) returns are here because zero is already taken by longjmp().
*/
#define AC_PERMIT 1 /* permit access */
#define AC_DENY (-1) /* deny_access */
#define AC_ERROR AC_DENY /* XXX */
/*
* In verification mode an option function should just say what it would do,
* instead of really doing it. An option function that would not return
* should clear the dry_run flag to inform the caller of this unusual
* behavior.
*/
extern void process_options(); /* execute options */
extern int dry_run; /* verification flag */
/* Bug workarounds. */
#ifdef INET_ADDR_BUG /* inet_addr() returns struct */
#define inet_addr fix_inet_addr
extern long fix_inet_addr();
#endif
#ifdef BROKEN_FGETS /* partial reads from sockets */
#define fgets fix_fgets
extern char *fix_fgets();
#endif
#ifdef RECVFROM_BUG /* no address family info */
#define recvfrom fix_recvfrom
extern int fix_recvfrom();
#endif
#ifdef GETPEERNAME_BUG /* claims success with UDP */
#define getpeername fix_getpeername
extern int fix_getpeername();
#endif
#ifdef SOLARIS_24_GETHOSTBYNAME_BUG /* lists addresses as aliases */
#define gethostbyname fix_gethostbyname
extern struct hostent *fix_gethostbyname();
#endif
#ifdef USE_STRSEP /* libc calls strtok() */
#define strtok fix_strtok
extern char *fix_strtok();
#endif
#ifdef LIBC_CALLS_STRTOK /* libc calls strtok() */
#define strtok my_strtok
extern char *my_strtok();
#endif