xio.h

   1 /* source: xio.h */
   2 /* Copyright Gerhard Rieger and contributors (see file CHANGES) */
   3 /* Published under the GNU General Public License V.2, see file COPYING */
   4
   5 #ifndef __xio_h_included
   6 #define __xio_h_included 1
   7
   8 #if 1 /*!*/
   9 #include "mytypes.h"
  10 #include "sysutils.h"
  11 #endif
  12
  13 #define XIO_MAXSOCK 2
  14
  15 /* Linux 2.2.10 */
  16 #define HAVE_STRUCT_LINGER 1
  17
  18 #define LINETERM_RAW 0
  19 #define LINETERM_CR 1
  20 #define LINETERM_CRNL 2
  21
  22 struct addrdesc;
  23 struct opt;
  24
  25 /* the flags argument of xioopen */
  26 #define XIO_RDONLY  O_RDONLY /* asserted to be 0 */
  27 #define XIO_WRONLY  O_WRONLY /* asserted to be 1 */
  28 #define XIO_RDWR    O_RDWR   /* asserted to be 2 */
  29 #define XIO_ACCMODE (XIO_RDONLY|XIO_WRONLY|XIO_RDWR)    /* must be 3 */
  30 #define XIO_MAYFORK     4 /* address is allowed to fork the program (fork) */
  31 #define XIO_MAYCHILD    8 /* address is allowed to fork off a child (exec)*/
  32 #define XIO_MAYEXEC    16 /* address is allowed to exec a prog (exec+nofork) */
  33 #define XIO_MAYCONVERT 32 /* address is allowed to perform modifications on the
  34                              stream data, e.g. SSL, REALDINE; CRLF */
  35
  36 /* the status flags of xiofile_t */
  37 #define XIO_DOESFORK    XIO_MAYFORK
  38 #define XIO_DOESCHILD   XIO_MAYCHILD
  39 #define XIO_DOESEXEC    XIO_MAYEXEC
  40 #define XIO_DOESCONVERT XIO_MAYCONVERT
  41
  42
  43 /* methods for reading and writing, and for related checks */
  44 #define XIODATA_READMASK        0xf000  /* mask for basic r/w method */
  45 #define XIOREAD_STREAM          0x1000  /* read() (default) */
  46 #define XIOREAD_RECV            0x2000  /* recvfrom() */
  47 #define XIOREAD_PTY             0x4000  /* handle EIO */
  48 #define XIOREAD_POSIXMQ         0x5000  /* POSIX MQ */
  49 #define XIOREAD_READLINE        0x6000  /* ... */
  50 #define XIOREAD_OPENSSL         0x7000  /* SSL_read() */
  51 #define XIODATA_WRITEMASK       0x0f00  /* mask for basic r/w method */
  52 #define XIOWRITE_STREAM         0x0100  /* write() (default) */
  53 #define XIOWRITE_SENDTO         0x0200  /* sendto() */
  54 #define XIOWRITE_PIPE           0x0300  /* write() to alternate (pipe) Fd */
  55 #define XIOWRITE_2PIPE          0x0400  /* write() to alternate (2pipe) Fd */
  56 #define XIOWRITE_POSIXMQ        0x0500  /* POSIX MQ */
  57 #define XIOWRITE_READLINE       0x0600  /* check for prompt */
  58 #define XIOWRITE_OPENSSL        0x0700  /* SSL_write() */
  59 /* modifiers to XIODATA_READ_RECV */
  60 #define XIOREAD_RECV_CHECKPORT  0x0001  /* recv, check peer port */
  61 #define XIOREAD_RECV_CHECKADDR  0x0002  /* recv, check peer address */
  62 #define XIOREAD_RECV_CHECKRANGE 0x0004  /* recv, check if peer addr in range */
  63 #define XIOREAD_RECV_ONESHOT    0x0008  /* give EOF after first packet */
  64 #define XIOREAD_RECV_SKIPIP     0x0010  /* recv, skip IPv4 header */
  65 #define XIOREAD_RECV_FROM       0x0020  /* remember peer for replying */
  66 #define XIOREAD_RECV_NOCHECK    0x0040  /* do not check peer */
  67
  68 /* combinations */
  69 #define XIODATA_MASK            (XIODATA_READMASK|XIODATA_WRITEMASK)
  70 #define XIODATA_STREAM          (XIOREAD_STREAM|XIOWRITE_STREAM)
  71 #define XIODATA_RECVFROM        (XIOREAD_RECV|XIOWRITE_SENDTO|XIOREAD_RECV_CHECKPORT|XIOREAD_RECV_CHECKADDR|XIOREAD_RECV_FROM)
  72 #define XIODATA_RECVFROM_SKIPIP (XIODATA_RECVFROM|XIOREAD_RECV_SKIPIP)
  73 #define XIODATA_RECVFROM_ONE    (XIODATA_RECVFROM|XIOREAD_RECV_ONESHOT)
  74 #define XIODATA_RECVFROM_SKIPIP_ONE     (XIODATA_RECVFROM_SKIPIP|XIOREAD_RECV_ONESHOT)
  75 #define XIODATA_RECV            (XIOREAD_RECV|XIOWRITE_SENDTO|XIOREAD_RECV_CHECKRANGE)
  76 #define XIODATA_RECV_SKIPIP     (XIODATA_RECV|XIOREAD_RECV_SKIPIP)
  77 #define XIODATA_PIPE            (XIOREAD_STREAM|XIOWRITE_PIPE)
  78 #define XIODATA_2PIPE           (XIOREAD_STREAM|XIOWRITE_2PIPE)
  79 #define XIODATA_POSIXMQ         (XIOREAD_POSIXMQ|XIOWRITE_POSIXMQ)
  80 #define XIODATA_PTY             (XIOREAD_PTY|XIOWRITE_STREAM)
  81 #define XIODATA_READLINE        (XIOREAD_READLINE|XIOWRITE_STREAM)
  82 #define XIODATA_OPENSSL         (XIOREAD_OPENSSL|XIOWRITE_OPENSSL)
  83
  84
  85 /* these are the values allowed for the "enum xiotag  tag" flag of the "struct
  86    single" and "union bipipe" (xiofile_t) structures. */
  87 enum xiotag {
  88    XIO_TAG_INVALID,     /* the record is not in use */
  89    XIO_TAG_RDONLY,      /* this is a single read-only stream */
  90    XIO_TAG_WRONLY,      /* this is a single write-only stream */
  91    XIO_TAG_RDWR,        /* this is a single read-write stream */
  92    XIO_TAG_DUAL,        /* this is a dual stream, consisting of two single
  93                            streams */
  94    XIO_TAG_CLOSED=8,    /* close, additional bit */
  95 } ;
  96
  97 /* Keep condition consistent with xioopts.h:GROUP_*! */
  98 #if WITH_POSIXMQ || WITH_SCTP || WITH_DCCP || WITH_UDPLITE
  99 typedef uint64_t groups_t;
 100 #define F_groups_t F_uint64_x
 101 #else
 102 typedef uint32_t groups_t;
 103 #define F_groups_t F_uint32_x
 104 #endif
 105
 106 /* global XIO options/parameters */
 107 typedef struct xioparms {
 108    bool strictopts;
 109    const char *pipesep;
 110    const char *paramsep;
 111    const char *optionsep;
 112    char ip4portsep;
 113    char ip6portsep;     /* do not change, might be hardcoded somewhere! */
 114    char logopt; /* 'm' means "switch to syslog when entering daemon mode" */
 115    const char *syslogfac;       /* syslog facility (only with mixed mode) */
 116    char default_ip;     /* default prot.fam for IP based listen ('4' '6' or '\0') */
 117    char preferred_ip;   /* preferred prot.fam. for name resolution ('0' for
 118                            unspecified, '4', or '6') */
 119    bool experimental;   /* enable some features */
 120    const char *sniffleft_name;          /* file name with -r */
 121    const char *sniffright_name;         /* file name with -R */
 122    size_t bufsiz;
 123 } xioparms_t;
 124
 125 /* pack the description of a lock file */
 126 typedef struct {
 127    const char     *lockfile;    /* name of lockfile; NULL if no locking */
 128    bool            waitlock;    /* dont't exit when already locked */
 129    struct timespec intervall;   /* polling intervall */
 130 } xiolock_t;
 131
 132 extern xioparms_t xioparms;
 133
 134 #define MAXARGV 8
 135
 136 #if _WITH_IP4 || _WITH_IP6
 137 #if WITH_RESOLVE && HAVE_RESOLV_H
 138 struct para_ip_res {
 139         unsigned int opts[2];   /* bits to be set in _res.options are in [0],
 140                                    bits to be cleared are in [1] */
 141 #if HAVE_RES_RETRANS
 142         int      retrans;
 143 #endif
 144 #if HAVE_RES_RETRY
 145         int      retry;
 146 #endif
 147 #if HAVE_RES_NSADDR_LIST
 148 #       undef nsaddr    /* resolv.h might define this, breaks debugger */
 149         struct sockaddr_in nsaddr;
 150 #endif
 151 } ;
 152 #endif /* WITH_RESOLVE && HAVE_RESOLV_H */
 153
 154 struct para_ip {
 155         int          ai_flags[2];       /* flags for getaddrinfo() ai_flags (set/unset) */
 156 #if WITH_RESOLVE && HAVE_RESOLV_H
 157         struct para_ip_res res;
 158 #endif
 159         bool     dosourceport;  /* check the source port of incoming connection or packets */
 160         uint16_t sourceport;            /* host byte order */
 161         bool     lowport;
 162 #if (WITH_TCP || WITH_UDP) && WITH_LIBWRAP
 163         bool   dolibwrap;
 164         char    *libwrapname;
 165         char    *tcpwrap_etc;
 166         char    *hosts_allow_table;
 167         char    *hosts_deny_table;
 168 #endif
 169 } ;
 170 #endif /* _WITH_IP4 || _WITH_IP6 */
 171
 172 /* a non-dual file descriptor */
 173 typedef struct single {
 174    enum xiotag tag;     /* see  enum xiotag  */
 175    const struct addrdesc *addr;
 176    int    flags;
 177    /* until here, keep consistent with bipipe.common !!! */
 178 #if WITH_RETRY
 179    unsigned int retry;  /* retry opening this many times */
 180    bool forever;        /* retry opening forever */
 181    struct timespec intervall;   /* wait so long between retries */
 182 #endif /* WITH_RETRY */
 183    bool   ignoreeof;    /* option ignoreeof; do not pass eof condition to app*/
 184    int    eof;          /* 1..exec'd child has died, but no explicit eof
 185                            occurred
 186                            2..fd0 has reached EOF, but check for ignoreeof
 187                            3..fd0 has reached EOF (definitely; never with
 188                            ignoreeof! */
 189    size_t wsize;        /* write always this size; 0..all available */
 190    size_t readbytes;    /* read only so many bytes; 0...unlimited */
 191    size_t actbytes;     /* so many bytes still to be read (when readbytes!=0)*/
 192    xiolock_t lock;      /* parameters of lockfile */
 193    bool      havelock;  /* we are happy owner of the above lock */
 194    int       triggerfd;         /* in child process close this FD to notify parent */
 195    bool      cool_write;        /* downlevel EPIPE, ECONNRESET to notice */
 196    /* until here, keep consistent with bipipe.dual ! */
 197    int argc;            /* number of fields in argv */
 198    const char *argv[MAXARGV];   /* address keyword, required args */
 199    struct opt *opts;    /* the options of this address */
 200    int    lineterm;     /* 0..dont touch; 1..CR; 2..CRNL on extern data */
 201    int    fd;
 202    bool   opt_unlink_close;     /* option unlink_close */
 203    char  *unlink_close; /* name of a symlink or unix socket to be removed */
 204    int dtype;
 205    enum {
 206       XIOSHUT_UNSPEC,   /* standard (address dependent) behaviour */
 207       XIOSHUT_NONE,     /* do nothing on shutdown */
 208       XIOSHUT_CLOSE,    /* close the FD */
 209       XIOSHUT_DOWN,     /* shutdown() */
 210       XIOSHUT_NULL      /* send an empty packet (dgram socket) */
 211    } howtoshut;
 212    enum {
 213       END_UNSPEC,       /* after init, when no end-close... option */
 214       END_NONE,         /* no action */
 215       END_CLOSE,        /* close() */
 216       END_SHUTDOWN,     /* shutdown() */
 217       END_KILL,         /* has subprocess */
 218       END_CLOSE_KILL,   /* first close fd, then kill subprocess */
 219       END_SHUTDOWN_KILL,/* first shutdown fd, then kill subprocess */
 220       END_INTERFACE     /* restore interface flags, then close fd */
 221    } howtoend;
 222 #if _WITH_SOCKET
 223    union sockaddr_union peersa;
 224    socklen_t salen;
 225 #endif /* _WITH_SOCKET */
 226 #if WITH_TERMIOS
 227    bool ttyvalid;               /* the following struct is valid */
 228    struct termios savetty;      /* save orig tty settings for later restore */
 229 #endif /* WITH_TERMIOS */
 230    int (*sigchild)(struct single *);    /* callback after sigchild */
 231    int escape;                  /* escape character; -1 for no escape */
 232    bool actescape;              /* escape character found in input data */
 233    int  shutup;                 /* children-shutup option */
 234    union {
 235       struct {
 236          int fdout;             /* use fd for output */
 237          int socktype;
 238       } bipipe;
 239 #if _WITH_SOCKET
 240       struct {
 241          /* keep a consistent copy in openssl part !!! */
 242          struct timeval connect_timeout; /* how long to hang in connect() */
 243 #if WITH_LISTEN
 244          struct timeval accept_timeout;  /* how long to wait for incoming connection */
 245 #endif
 246          union sockaddr_union la;       /* local socket address */
 247          bool null_eof;         /* with dgram: empty packet means EOF */
 248          bool dorange;
 249          struct xiorange range; /* restrictions for peer address */
 250 #if _WITH_IP4 || _WITH_IP6
 251          struct para_ip ip;
 252 #endif /* _WITH_IP4 || _WITH_IP6 */
 253          /* Copy in openssl part up to here ! */
 254 #if HAVE_STRUCT_TPACKET_AUXDATA
 255          struct {
 256             int     packet_auxdata;
 257          } ancill_flag;
 258 #endif
 259 #if HAVE_STRUCT_TPACKET_AUXDATA
 260          struct tpacket_auxdata ancill_data_packet_auxdata;
 261          bool retrieve_vlan;
 262 #endif
 263 #if WITH_UNIX
 264          struct {
 265             bool     tight;
 266          } un;
 267 #endif /* WITH_UNIX */
 268       } socket;
 269 #endif /* _WITH_SOCKET */
 270 #if WITH_POSIXMQ
 271       struct {
 272          const char *name;
 273          unsigned int prio;             /* POSIX message queue */
 274       } posixmq;
 275 #endif /* WITH_POSIXMQ */
 276       struct {
 277          int fdout;             /* use fd for output if two pipes */
 278          pid_t pid;             /* child PID, with EXEC: */
 279          struct timeval sitout_eio;
 280       } exec;
 281 #if WITH_READLINE
 282       struct {
 283          char *history_file;
 284          char *prompt;          /* static prompt, passed to readline() */
 285          size_t dynbytes;       /* length of buffer for dynamic prompt */
 286          char *dynprompt;       /* the dynamic prompt */
 287          char *dynend;          /* current end of dynamic prompt */
 288 #if HAVE_REGEX_H
 289          bool    hasnoecho;     /* following regex is set */
 290          regex_t noecho;        /* if it matches the prompt, input is silent */
 291 #endif
 292       } readline;
 293 #endif /* WITH_READLINE */
 294 #if WITH_OPENSSL
 295       struct {
 296          /* copy of the para.socket structure without un !!! */
 297          struct timeval connect_timeout; /* how long to hang in connect() */
 298 #if WITH_LISTEN
 299          struct timeval accept_timeout;  /* how long to wait for incoming connection */
 300 #endif
 301          union sockaddr_union la;       /* local socket address */
 302          bool null_eof;         /* with dgram: empty packet means EOF */
 303          bool dorange;
 304          struct xiorange range; /* restrictions for peer address */
 305 #if _WITH_IP4 || _WITH_IP6
 306          struct para_ip ip;
 307 #endif /* _WITH_IP4 || _WITH_IP6 */
 308          /* end of the para.socket structure copy */
 309          SSL_CTX* ctx;  /* for freeing on close */
 310          SSL *ssl;
 311 #if HAVE_SSL_CTX_set_min_proto_version || defined(SSL_CTX_set_min_proto_version)
 312          char *min_proto_version;
 313 #endif
 314 #if HAVE_SSL_CTX_set_max_proto_version || defined(SSL_CTX_set_max_proto_version)
 315          char *max_proto_version;
 316 #endif
 317       } openssl;
 318 #endif /* WITH_OPENSSL */
 319 #if _WITH_INTERFACE
 320       struct {
 321          char name[IFNAMSIZ];   /* name of interface */
 322          short save_iff;        /* for restoring old settings on exit */
 323          short iff_opts[2];     /* ifr flags, using OFUNC_OFFSET_MASKS */
 324       } interface;
 325 #endif /* _WITH_INTERFACE */
 326    } para;
 327 #if WITH_STATS
 328    unsigned long long blocks_read;
 329    unsigned long long bytes_read;
 330    unsigned long long blocks_written;
 331    unsigned long long bytes_written;
 332 #endif /* WITH_STATS */
 333 } xiosingle_t;
 334
 335 /* rw: 0..read, 1..write, 2..r/w */
 336 /* when implementing a new address type take care of following topics:
 337    . be aware that xioopen_single is used for O_RDONLY, O_WRONLY, and O_RDWR data
 338    . which options are allowed (option groups)
 339    . implement application of all these options
 340    . set FD_CLOEXEC on new file descriptors BEFORE the cloexec option might be
 341      applied
 342    .
 343 */
 344
 345 typedef union bipipe {
 346    enum xiotag    tag;
 347    struct {
 348       enum xiotag tag;
 349       const struct addrdesc *addr;
 350       int         flags;
 351       /* until here, keep consistent with struct single, and with .dual */
 352    } common;    /* "bipipe.common" */
 353    struct single  stream;
 354    struct {
 355       enum xiotag tag;
 356       const struct addrdesc *addr;
 357       int         flags;        /* compatible to fcntl(.., F_GETFL, ..) */
 358 #if WITH_RETRY
 359       unsigned retry;   /* retry opening this many times */
 360       bool forever;     /* retry opening forever */
 361       struct timespec intervall;        /* wait so long between retries */
 362 #endif /* WITH_RETRY */
 363       bool        ignoreeof;
 364       int         eof;          /* fd0 has reached EOF */
 365       size_t      wsize;        /* write always this size; 0..all available */
 366       size_t readbytes; /* read only so many bytes; 0...unlimited */
 367       size_t actbytes;  /* so many bytes still to be read */
 368       xiolock_t lock;   /* parameters of lockfile */
 369       bool      havelock;       /* we are happy owner of the above lock */
 370       int       triggerfd;      /* close this FD in child process to notify parent */
 371       bool      cool_write;     /* downlevel EPIPE, ECONNRESET to notice */
 372       /* until here, keep consistent with struct single ! */
 373       struct single *stream[2]; /* input stream, output stream */
 374    } dual;
 375 } xiofile_t;
 376
 377
 378 struct addrdesc {
 379    const char *defname; /* main (canonical) name of address */
 380    int directions;      /* 1..read, 2..write, 3..both */
 381    int (*func)(int argc, const char *argv[], struct opt *opts, int rw, xiofile_t *fd, const struct addrdesc *addrdesc);
 382    groups_t groups;
 383    int arg1;
 384    int arg2;
 385    int arg3;
 386 #if WITH_HELP
 387    const char *syntax;
 388 #endif
 389 } ;
 390
 391 #define XIO_WRITABLE(s) (((s)->common.flags+1)&2)
 392 #define XIO_READABLE(s) (((s)->common.flags+1)&1)
 393 #define XIO_RDSTREAM(s) (((s)->tag==XIO_TAG_DUAL)?(s)->dual.stream[0]:&(s)->stream)
 394 #define XIO_WRSTREAM(s) (((s)->tag==XIO_TAG_DUAL)?(s)->dual.stream[1]:&(s)->stream)
 395 #define XIO_GETRDFD(s) (((s)->tag==XIO_TAG_DUAL)?(s)->dual.stream[0]->fd:(s)->stream.fd)
 396 #define XIO_GETWRFD(s) (((s)->tag==XIO_TAG_DUAL)?(s)->dual.stream[1]->fd:(((s)->stream.dtype&XIODATA_WRITEMASK)==XIOWRITE_2PIPE)?(s)->stream.para.exec.fdout:(((s)->stream.dtype&XIODATA_WRITEMASK)==XIOWRITE_PIPE)?(s)->stream.para.bipipe.fdout:(s)->stream.fd)
 397 #define XIO_EOF(s) (XIO_RDSTREAM(s)->eof && !XIO_RDSTREAM(s)->ignoreeof)
 398
 399 typedef unsigned long flags_t;
 400
 401 union integral {
 402    bool           u_bool;
 403    uint8_t        u_byte;
 404    gid_t          u_gidt;
 405    int            u_int;
 406    long           u_long;
 407 #if HAVE_TYPE_LONGLONG
 408    long long      u_longlong;
 409 #endif
 410    double         u_double;
 411    mode_t         u_modet;
 412    short          u_short;
 413    size_t         u_sizet;
 414    char          *u_string;
 415    uid_t          u_uidt;
 416    unsigned int   u_uint;
 417    unsigned long  u_ulong;
 418    unsigned short u_ushort;
 419    uint16_t       u_2bytes;
 420    void          *u_ptr;
 421    flags_t        u_flag;
 422    struct {
 423       uint8_t    *b_data;
 424       size_t      b_len;
 425    }              u_bin;
 426    struct timeval u_timeval;
 427 #if HAVE_STRUCT_LINGER
 428    struct linger  u_linger;
 429 #endif /* HAVE_STRUCT_LINGER */
 430 #if HAVE_STRUCT_TIMESPEC
 431    struct timespec u_timespec;
 432 #endif /* HAVE_STRUCT_TIMESPEC */
 433 #if WITH_IP4
 434    struct in_addr  u_ip4addr;
 435    struct sockaddr_in  u_ip4sock;
 436 #endif
 437 } ;
 438
 439 /* some aliases */
 440
 441 #if HAVE_BASIC_OFF_T==3
 442 #  define u_off u_int
 443 #elif HAVE_BASIC_OFF_T==5
 444 #  define u_off u_long
 445 #elif HAVE_BASIC_OFF_T==7
 446 #  define u_off u_longlong
 447 #else
 448 #  error "unexpected size of off_t, please report this as bug"
 449 #endif
 450
 451 #if defined(HAVE_BASIC_OFF64_T) && HAVE_BASIC_OFF64_T
 452 #  if HAVE_BASIC_OFF64_T==5
 453 #     define u_off64 u_long
 454 #  elif HAVE_BASIC_OFF64_T==7
 455 #     define u_off64 u_longlong
 456 #  else
 457 #     error "unexpected size of off64_t, please report this as bug"
 458 #  endif
 459 #endif /* defined(HAVE_BASIC_OFF64_T) && HAVE_BASIC_OFF64_T */
 460
 461
 462 /* this handles option instances, for communication between subroutines */
 463 struct opt {
 464    const struct optdesc *desc;
 465    union integral value;
 466    union integral value2;
 467    union integral value3;
 468 } ;
 469
 470 extern const char *PIPESEP;
 471 extern xiofile_t *sock[XIO_MAXSOCK];
 472
 473 extern int num_child;
 474 extern bool first_child;
 475
 476 /* return values of xioopensingle */
 477 #define STAT_OK         0
 478 #define STAT_WARNING    1
 479 #define STAT_EXIT       2
 480 #define STAT_NOACTION   3       /* by retropt_* when option not applied */
 481 #define STAT_RETRYNOW   -1      /* only after timeouts useful ? */
 482 #define STAT_RETRYLATER -2      /* address cannot be opened, but user might
 483                                    change something in the filesystem etc. to
 484                                    make this process succeed later. */
 485 #define STAT_NORETRY    -3      /* address syntax error, not implemented etc;
 486                                    not even by external changes correctable */
 487
 488 extern int xioinitialize(void);
 489 extern int xioinitialize2(void);
 490 extern pid_t xio_fork(bool subchild, int level, int shutup);
 491 extern int xio_forked_inchild(void);
 492 extern int xiosetopt(char what, const char *arg);
 493 extern int xioinqopt(char what, char *arg, size_t n);
 494 extern xiofile_t *xioopen(const char *args, int flags);
 495 extern int xioopensingle(char *addr, struct single *xfd, int xioflags);
 496 extern int xioopenhelp(FILE *of, int level);
 497
 498 /* must be outside function for use by childdied handler */
 499 extern xiofile_t *sock1, *sock2;
 500 extern int sniffleft, sniffright;
 501
 502 #define NUMUNKNOWN 4
 503 extern pid_t diedunknown[NUMUNKNOWN];   /* child died before it is registered */
 504 #define diedunknown1 (diedunknown[0])
 505 #define diedunknown2 (diedunknown[1])
 506 #define diedunknown3 (diedunknown[2])
 507 #define diedunknown4 (diedunknown[3])
 508 extern int   statunknown[NUMUNKNOWN];   /* exit state of unknown dead child */
 509 extern int engine_result;               /* here signal handler overrides OK */
 510
 511 extern int xiosetsigchild(xiofile_t *xfd, int (*callback)(struct single *));
 512 extern int xiosetchilddied(void);
 513 extern int xio_opt_signal(pid_t pid, int signum);
 514 extern void childdied(int signum);
 515
 516 extern ssize_t xioread(xiofile_t *sock1, void *buff, size_t bufsiz);
 517 extern ssize_t xiopending(xiofile_t *sock1);
 518 extern ssize_t xiowrite(xiofile_t *sock1, const void *buff, size_t bufsiz);
 519 extern int xioshutdown(xiofile_t *sock, int how);
 520
 521 extern int xioclose(xiofile_t *sock);
 522 extern void xioexit(void);
 523
 524 extern int (*xiohook_newchild)(void);   /* xio calls this function from a new child process */
 525
 526 #endif /* !defined(__xio_h_included) */