3 * $Id: sw_rsh.c,v 1.1 1999/06/02 16:53:34 mdw Exp $
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of sw-tools.
14 * sw-tools is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * sw-tools is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with sw-tools; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.1 1999/06/02 16:53:34 mdw
37 /*----- Header files ------------------------------------------------------*/
49 #include <sys/types.h>
54 #include <sys/socket.h>
58 extern char **environ
;
61 #include <mLib/alloc.h>
62 #include <mLib/dstr.h>
64 #include <mLib/mdwopt.h>
65 #include <mLib/quis.h>
66 #include <mLib/report.h>
75 /*----- Data structures ---------------------------------------------------*/
77 typedef unsigned char octet
;
81 typedef struct pkhead
{
86 /*----- Static variables --------------------------------------------------*/
88 static int handler
= 0;
89 static rcmd
*rcmds
= RCMD_LINK
;
91 /*----- Packet interface --------------------------------------------------*/
95 * Arguments: @sw_remote@ = pointer to the remote block
96 * @int type@ = packet type to send
97 * @const void *p@ = pointer to packet data
98 * @size_t sz@ = size of data to send
100 * Returns: Zero if it worked, nonzero otherwise.
102 * Use: Sends a data packet. If the type is `data', then `sz' may be
103 * arbitrarily large and is divided into small eenough chunks.
104 * Otherwise it's an error to send a packet that's too big.
107 int pksend(sw_remote
*r
, int type
, const void *p
, size_t sz
)
113 /* --- Sort out error conditions --- */
115 if (sz
> PKMAX
&& type
!= PKTYPE_DATA
) {
120 /* --- Main output loop --- */
125 /* --- Set up the packet header --- */
127 chunk
= (sz
> PKMAX ? PKMAX
: sz
);
128 h
.len
[0] = chunk
& 0xff;
129 h
.len
[1] = (chunk
>> 8) & 0xff;
131 /* --- Write the packet header --- */
134 if (write(r
->fdout
, &h
, PKHEADSZ
) < PKHEADSZ
) {
140 /* --- Write the payload, if there is one --- *
142 * Maybe the OS won't want to bite it all off in one go.
146 ssize_t n
= write(r
->fdout
, q
, chunk
);
147 if (n
< 0 && errno
!= EINTR
)
162 /* --- @pkrecv@ --- *
164 * Arguments: @sw_remote *r@ = remote block
166 * Returns: Packet type received, or @-1@ for an error.
168 * Use: Receives a packet from the remote host. The packet data is
169 * placed in the block's buffer, the block's packet length is
170 * diddled appropriately.
173 int pkrecv(sw_remote
*r
)
180 /* --- Read the packet header --- */
185 n
= read(r
->fdin
, p
, sz
);
186 if (n
< 0 && errno
!= EINTR
)
196 /* --- Hack for error messages --- *
198 * If it doesn't look like a valid packet, read a `chunk' and pretend it's
199 * data. This isn't too bad, because all the packet types are control
200 * codes, and are unlikely to be in a textual message.
202 * Normally what happens here is that something sitting before the `sw'
203 * program fails, reports a plain textual error, and exits. Grabbing the
204 * `last gasp' like this, then, traps that error message and allows
205 * something to report it. The rest ought to be completely silent, so I
206 * get an `unexpected eof' and then drop everything.
208 * This is certainly better than the behaviour otherwise, which is an
209 * @E2BIG@ message reported when the packet size is really ASCII
213 if (h
.type
>= PKTYPE_BOGUS
) {
214 memcpy(r
->buf
, &h
, PKHEADSZ
);
215 n
= read(r
->fdin
, r
->buf
+ PKHEADSZ
, sizeof(r
->buf
) - PKHEADSZ
);
218 r
->sz
= n
+ PKHEADSZ
;
219 return (PKTYPE_DATA
);
222 /* --- Sort out what's going on --- */
224 sz
= h
.len
[0] | (h
.len
[1] << 8);
233 /* --- Read the packet payload --- */
237 n
= read(r
->fdin
, p
, sz
);
238 if (n
< 0 && errno
!= EINTR
)
251 /*----- Error reporting and exit statuses --------------------------------*/
253 /* --- @swexit@ --- *
255 * Arguments: @sw_remote *r@ = remote context
256 * @int status@ = exit status to return
260 * Use: Reports the exit status via packet protocol and quits.
263 void swexit(sw_remote
*r
, int status
)
265 unsigned char s
= status
;
266 pksend(r
, PKTYPE_STATUS
, &s
, 1);
270 /* --- @swsignal@ --- *
272 * Arguments: @sw_remote *r@ = remote context
273 * @int sig@ = signal ocurrence to return
277 * Use: Reports a signalled-to-death status via packet protocol and
281 void swsignal(sw_remote
*r
, int sig
)
283 #if defined(HAVE_STRSIGNAL)
284 char *s
= strsignal(sig
);
285 #elif defined(HAVE__SYS_SIGLIST)
286 char *s
= _sys_siglist
[sig
];
289 sprintf(s
, "signal %i", sig
);
292 pksend(r
, PKTYPE_STATUS
, s
, strlen(s
) + 1);
296 /* --- @swwait@ --- *
298 * Arguments: @sw_remote *r@ = remote context
299 * @int status@ = status answer from @wait@(2)
303 * Use: Reports a child's demise appropriately, and quits.
306 void swwait(sw_remote
*r
, int status
)
308 if (WIFEXITED(status
))
309 swexit(r
, WEXITSTATUS(status
));
310 else if (WIFSIGNALED(status
))
311 swsignal(r
, WTERMSIG(status
));
316 /* --- @swvprintf@ --- *
318 * Arguments: @sw_remote *r@ = remote context
319 * @const char *format@ = format string
320 * @va_list ap@ = things to format
324 * Use: Writes a string to the remote end. This is the low-level bit
328 void swvprintf(sw_remote
*r
, const char *format
, va_list ap
)
331 dstr_vputf(&d
, format
, ap
);
332 pksend(r
, PKTYPE_DATA
, d
.buf
, d
.len
);
336 /* --- @swprintf@ --- *
338 * Arguments: @sw_remote *r@ = remote context
339 * @const char *format@ = format string
340 * @...@ = other arguments
344 * Use: Writes a string to the remote end.
347 void swprintf(sw_remote
*r
, const char *format
, ...)
350 va_start(ap
, format
);
351 swvprintf(r
, format
, ap
);
357 * Arguments: @sw_remote *r@ = remote context
358 * @int status@ = exit status to report
359 * @const char *format@ = format string to fill in
360 * @...@ = other arguments
364 * Use: Reports a message and quits.
367 void swdie(sw_remote
*r
, int status
, const char *format
, ...)
372 va_start(ap
, format
);
373 dstr_putf(&d
, "%s [remote]: ", QUIS
);
374 dstr_vputf(&d
, format
, ap
);
378 pksend(r
, PKTYPE_DATA
, d
.buf
, d
.len
);
383 /*----- Command handling and dispatch -------------------------------------*/
385 /* --- @remote@ --- *
387 * Arguments: @sw_remote *r@ = pointer to remote block
388 * @const char *cmd@ = command to run
389 * @char *argv[]@ = argument array
390 * @char *env[]@ = environment variables
392 * Returns: Doesn't. Reports an exit status through packet protocol and
395 * Use: Dispatches a remote command. At this point, the two code
396 * paths for local and remote invokation have joined again.
399 static void remote(sw_remote
*r
, const char *cmd
, char *argv
[], char *env
[])
401 struct rcmd
*p
, *chosen
= 0;
402 size_t sz
= strlen(cmd
);
404 /* --- Make sure that I can get the exit status of children --- */
406 signal(SIGCHLD
, SIG_DFL
);
408 /* --- Fix up the environment --- */
414 if (env
!= environ
) {
416 env_import(&t
, environ
);
418 env_put(&t
, "SW_ARCH", ARCH
);
419 env_file(&t
, DATADIR
"/sw-env");
420 env
= env_export(&t
);
423 /* --- Dispatch to the command handler --- */
425 for (p
= rcmds
; p
; p
= p
->next
) {
426 if (strncmp(cmd
, p
->name
, sz
) == 0) {
427 if (p
->name
[sz
] == 0) {
431 swdie(r
, 1, "ambiguous remote command name `%s'", cmd
);
437 swdie(r
, 1, "unknown remote command name `%s'", cmd
);
438 chosen
->rcmd(r
, argv
, env
);
441 /*----- Remote invocation -------------------------------------------------*/
443 /* --- @sendargv@ --- *
445 * Arguments: @sw_remote *r@ = pointer to the remote context
446 * @int type@ = packet type to send with
447 * @char *v[]@ = pointer to the array to send
449 * Returns: Zero if OK, nonzero if it failed.
451 * Use: Sends something @argv@-shaped; i.e., an array of strings
452 * terminated by a null pointer.
455 static int sendargv(sw_remote
*r
, int type
, char *v
[])
462 d
.len
++; /* Make the null `real' */
465 e
= pksend(r
, type
, d
.buf
, d
.len
);
470 /* --- @snarfargv@ --- *
472 * Arguments: @const char *buf@ = pointer to buffer
473 * @size_t sz@ = size of buffer
475 * Returns: Pointer to argument array (allocated with @malloc@).
477 * Use: Snarfs the null-terminated strings in the buffer and returns
478 * an array of them. The whole lot, strings and array, is
479 * returned in one big chunk allocated from the heap. Note that
480 * this means it's OK to throw the initial buffer away.
483 static char **snarfargv(const char *buf
, size_t sz
)
485 /* --- Initial setup --- */
492 /* --- Pass one: count the number of arguments --- */
508 /* --- Allocate memory for everything --- */
510 v
= xmalloc((c
+ 1) * sizeof(char *) + sz
+ 1);
511 q
= (char *)(v
+ c
+ 1);
514 /* --- Pass two: set up the arrays --- */
536 /* --- @swrsh_remote@ --- *
538 * Arguments: @const char *cmd@ = the command to perform
540 * Returns: Doesn't. Reports an exit status through packet protocol and
543 * Use: Handles the remote end of a remote job invokation.
546 void swrsh_remote(const char *cmd
)
549 static char *dummy
= 0;
556 /* --- Read packets from the remote host --- */
562 swdie(&r
, 1, "error reading packet: %s", strerror(errno
));
569 argv
= snarfargv(r
.buf
, r
.sz
);
574 env
= snarfargv(r
.buf
, r
.sz
);
580 dir
= xstrdup(r
.buf
);
586 swdie(&r
, 1, "internal error: unexpected packet");
591 /* --- Sort out any missing arguments --- */
601 /* --- Run the command --- */
604 remote(&r
, cmd
, argv
, env
);
605 CATCH
switch (exc_type
) {
607 static char msg
[] = "\nsw [remote]: not enough memory\n";
608 pksend(&r
, PKTYPE_DATA
, msg
, sizeof(msg
) - 1);
612 swdie(&r
, 1, "uncaught exception, type = %lx", exc_type
);
616 /*----- Starting remote jobs ----------------------------------------------*/
618 /* --- @sigchld@ --- *
620 * Arguments: @int sig@ = the signal number
624 * Use: Catches @SIGCHLD@ and reaps any children that have lost.
627 static void sigchld(int sig
)
631 while (waitpid(-1, &status
, WNOHANG
) > 0) {
632 if (WIFEXITED(status
)) {
633 fprintf(stderr
, "reap child with exit status %i\n",
634 WEXITSTATUS(status
));
635 } else if (WIFSIGNALED(status
)) {
636 fprintf(stderr
, "reap child killed by signal %s\n",
637 strsignal(WTERMSIG(status
)));
639 fprintf(stderr
, "reaped bizarre child which is still alive\n");
642 while (waitpid(-1, 0, WNOHANG
) > 0)
649 * Arguments: @sw_remote *r@ = remote process block to look after
650 * @const char *host@ = host to run on (0 for this one)
651 * @const char *cmd@ = remote command to run
652 * @char *argv[]@ = arguments to pass on
654 * Returns: Zero if it worked, nonzero if not.
656 * Use: Runs a command on a remote host. The argument array is
657 * mangled to come out OK at the far end. The environment and
658 * current directory are also passed along, and pop out the
659 * other end unmolested.
662 int swrsh(sw_remote
*r
, const char *host
, const char *cmd
, char *argv
[])
667 /* --- Get a socket pair for communicating with the other end --- */
669 if (socketpair(PF_UNIX
, SOCK_STREAM
, 0, sk
))
672 /* --- Set up a signal handler --- */
676 sa
.sa_handler
= sigchld
;
678 sigemptyset(&sa
.sa_mask
);
679 sigaction(SIGCHLD
, &sa
, 0);
683 /* --- Fork off a child to cope with stuff --- */
689 /* --- Handle the child process --- *
691 * If this is a local job, then just loop around inside to handle the
692 * `remote' command. Otherwise crank up `rsh' and pass the command over to
693 * a remote copy of myself.
695 * (Why do I need a separate process for local jobs? I don't really, but
696 * it makes everything much simpler when running multiple jobs at the same
703 /* --- Child end of a local job --- */
706 r
->fdin
= r
->fdout
= sk
[1];
707 remote(r
, cmd
, argv
, environ
);
710 /* --- Local child end of a remote job --- */
719 rsh
= getenv("SW_RSH");
722 execlp(rsh
, rsh
, host
, PATH_SW
, "--remote", cmd
, (char *)0);
725 /* --- I don't expect either to come back --- */
730 /* --- Local sort out of what to do --- *
732 * Either way, I've now got a socket tied to something which speaks my
733 * communication protocol. However, if this is a local job, then I can get
734 * going right away; otherwise, I've got to transmit various bits of
735 * information over the protocol.
738 r
->fdin
= r
->fdout
= sk
[0];
743 if (!getcwd(buf
, sizeof(buf
)))
745 sendargv(r
, PKTYPE_ARGS
, argv
);
746 sendargv(r
, PKTYPE_ENV
, environ
);
747 pksend(r
, PKTYPE_DIR
, buf
, strlen(buf
) + 1);
748 pksend(r
, PKTYPE_GO
, 0, 0);
751 /* --- Ready to rock'n'roll --- */
756 /* --- Tidy up if it failed --- */
765 /*----- Subcommands -------------------------------------------------------*/
767 /* --- @swrsh_rsh@ --- */
769 void rsw_rsh(sw_remote
*r
, char *argv
[], char *env
[])
775 /* --- Create a pipe --- */
778 swdie(r
, 1, "couldn't create pipe: %s", strerror(errno
));
780 /* --- Start the child process up --- */
784 swdie(r
, 1, "fork failed: %s", strerror(errno
));
788 /* --- Use my new environment --- */
790 environ
= env
; /* Yuk. */
792 /* --- Fiddle with pipe file descriptors --- */
800 /* --- Make sure it doesn't get any input --- */
803 fd
= open("/dev/null", O_RDONLY
);
809 /* --- Run the program --- */
811 execvp(argv
[0], argv
);
812 die(1, "couldn't exec `%s': %s", argv
[0], strerror(errno
));
815 /* --- Read the data from the pipe until it closes --- */
819 ssize_t n
= read(pfd
[0], r
->buf
, sizeof(r
->buf
));
821 swdie(r
, 1, "read error: %s", strerror(errno
));
825 pksend(r
, PKTYPE_DATA
, r
->buf
, n
);
829 /* --- Finally, reap the exit status and pass it on --- */
836 swdie(r
, 1, "error reaping child: %s", strerror(errno
));
841 /* --- @sw_rsh@ --- */
843 int sw_rsh(int argc
, char *argv
[])
849 /* --- Check the arguments --- */
852 die(1, "Usage: rsh HOST|ARCH COMMAND [ARGS...]");
854 /* --- Translate architecture names into hostnames --- */
856 if (strcmp(argv
[1], "-") == 0)
859 archent
*a
= arch_lookup(argv
[1], 0);
862 else if (a
->flags
& archFlag_home
)
868 /* --- Start the remote process --- */
870 if (swrsh(&r
, h
, "rsh", argv
+ 2))
871 die(1, "remote shell failed: %s", strerror(errno
));
873 /* --- Cope with packets from the remote process --- */
880 die(1, "error reading packet: %s", strerror(errno
));
882 write(STDOUT_FILENO
, r
.buf
, r
.sz
);
888 moan("command exited due to signal: %s", r
.buf
);
891 moan("command exited with status %i", r
.buf
[0]);
895 moan("command exited unexpectedly");
898 die(1, "unexpected packet type");
902 /* --- Finished --- */
909 /*----- That's all, folks -------------------------------------------------*/