3 * $Id: sw_rsh.c,v 1.2 1999/06/02 17:03:29 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 1.2 1999/06/02 17:03:29 mdw
33 * Fix use of `octet' now that mLib includes `bits.h' (as of version 1.3.5
34 * release). Also use the mLib load and store macros rather than doing it
37 * Revision 1.1.1.1 1999/06/02 16:53:34 mdw
42 /*----- Header files ------------------------------------------------------*/
54 #include <sys/types.h>
59 #include <sys/socket.h>
63 extern char **environ;
66 #include <mLib/alloc.h>
67 #include <mLib/bits.h>
68 #include <mLib/dstr.h>
70 #include <mLib/mdwopt.h>
71 #include <mLib/quis.h>
72 #include <mLib/report.h>
81 /*----- Data structures ---------------------------------------------------*/
85 typedef struct pkhead {
90 /*----- Static variables --------------------------------------------------*/
92 static int handler = 0;
93 static rcmd *rcmds = RCMD_LINK;
95 /*----- Packet interface --------------------------------------------------*/
99 * Arguments: @sw_remote@ = pointer to the remote block
100 * @int type@ = packet type to send
101 * @const void *p@ = pointer to packet data
102 * @size_t sz@ = size of data to send
104 * Returns: Zero if it worked, nonzero otherwise.
106 * Use: Sends a data packet. If the type is `data', then `sz' may be
107 * arbitrarily large and is divided into small eenough chunks.
108 * Otherwise it's an error to send a packet that's too big.
111 int pksend(sw_remote *r, int type, const void *p, size_t sz)
117 /* --- Sort out error conditions --- */
119 if (sz > PKMAX && type != PKTYPE_DATA) {
124 /* --- Main output loop --- */
129 /* --- Set up the packet header --- */
131 chunk = (sz > PKMAX ? PKMAX : sz);
132 STORE16(h.len, chunk);
134 /* --- Write the packet header --- */
137 if (write(r->fdout, &h, PKHEADSZ) < PKHEADSZ) {
143 /* --- Write the payload, if there is one --- *
145 * Maybe the OS won't want to bite it all off in one go.
149 ssize_t n = write(r->fdout, q, chunk);
150 if (n < 0 && errno != EINTR)
165 /* --- @pkrecv@ --- *
167 * Arguments: @sw_remote *r@ = remote block
169 * Returns: Packet type received, or @-1@ for an error.
171 * Use: Receives a packet from the remote host. The packet data is
172 * placed in the block's buffer, the block's packet length is
173 * diddled appropriately.
176 int pkrecv(sw_remote *r)
183 /* --- Read the packet header --- */
188 n = read(r->fdin, p, sz);
189 if (n < 0 && errno != EINTR)
199 /* --- Hack for error messages --- *
201 * If it doesn't look like a valid packet, read a `chunk' and pretend it's
202 * data. This isn't too bad, because all the packet types are control
203 * codes, and are unlikely to be in a textual message.
205 * Normally what happens here is that something sitting before the `sw'
206 * program fails, reports a plain textual error, and exits. Grabbing the
207 * `last gasp' like this, then, traps that error message and allows
208 * something to report it. The rest ought to be completely silent, so I
209 * get an `unexpected eof' and then drop everything.
211 * This is certainly better than the behaviour otherwise, which is an
212 * @E2BIG@ message reported when the packet size is really ASCII
216 if (h.type >= PKTYPE_BOGUS) {
217 memcpy(r->buf, &h, PKHEADSZ);
218 n = read(r->fdin, r->buf + PKHEADSZ, sizeof(r->buf) - PKHEADSZ);
221 r->sz = n + PKHEADSZ;
222 return (PKTYPE_DATA);
225 /* --- Sort out what's going on --- */
236 /* --- Read the packet payload --- */
240 n = read(r->fdin, p, sz);
241 if (n < 0 && errno != EINTR)
254 /*----- Error reporting and exit statuses --------------------------------*/
256 /* --- @swexit@ --- *
258 * Arguments: @sw_remote *r@ = remote context
259 * @int status@ = exit status to return
263 * Use: Reports the exit status via packet protocol and quits.
266 void swexit(sw_remote *r, int status)
268 unsigned char s = status;
269 pksend(r, PKTYPE_STATUS, &s, 1);
273 /* --- @swsignal@ --- *
275 * Arguments: @sw_remote *r@ = remote context
276 * @int sig@ = signal ocurrence to return
280 * Use: Reports a signalled-to-death status via packet protocol and
284 void swsignal(sw_remote *r, int sig)
286 #if defined(HAVE_STRSIGNAL)
287 char *s = strsignal(sig);
288 #elif defined(HAVE__SYS_SIGLIST)
289 char *s = _sys_siglist[sig];
292 sprintf(s, "signal %i", sig);
295 pksend(r, PKTYPE_STATUS, s, strlen(s) + 1);
299 /* --- @swwait@ --- *
301 * Arguments: @sw_remote *r@ = remote context
302 * @int status@ = status answer from @wait@(2)
306 * Use: Reports a child's demise appropriately, and quits.
309 void swwait(sw_remote *r, int status)
311 if (WIFEXITED(status))
312 swexit(r, WEXITSTATUS(status));
313 else if (WIFSIGNALED(status))
314 swsignal(r, WTERMSIG(status));
319 /* --- @swvprintf@ --- *
321 * Arguments: @sw_remote *r@ = remote context
322 * @const char *format@ = format string
323 * @va_list ap@ = things to format
327 * Use: Writes a string to the remote end. This is the low-level bit
331 void swvprintf(sw_remote *r, const char *format, va_list ap)
334 dstr_vputf(&d, format, ap);
335 pksend(r, PKTYPE_DATA, d.buf, d.len);
339 /* --- @swprintf@ --- *
341 * Arguments: @sw_remote *r@ = remote context
342 * @const char *format@ = format string
343 * @...@ = other arguments
347 * Use: Writes a string to the remote end.
350 void swprintf(sw_remote *r, const char *format, ...)
353 va_start(ap, format);
354 swvprintf(r, format, ap);
360 * Arguments: @sw_remote *r@ = remote context
361 * @int status@ = exit status to report
362 * @const char *format@ = format string to fill in
363 * @...@ = other arguments
367 * Use: Reports a message and quits.
370 void swdie(sw_remote *r, int status, const char *format, ...)
375 va_start(ap, format);
376 dstr_putf(&d, "%s [remote]: ", QUIS);
377 dstr_vputf(&d, format, ap);
381 pksend(r, PKTYPE_DATA, d.buf, d.len);
386 /*----- Command handling and dispatch -------------------------------------*/
388 /* --- @remote@ --- *
390 * Arguments: @sw_remote *r@ = pointer to remote block
391 * @const char *cmd@ = command to run
392 * @char *argv[]@ = argument array
393 * @char *env[]@ = environment variables
395 * Returns: Doesn't. Reports an exit status through packet protocol and
398 * Use: Dispatches a remote command. At this point, the two code
399 * paths for local and remote invokation have joined again.
402 static void remote(sw_remote *r, const char *cmd, char *argv[], char *env[])
404 struct rcmd *p, *chosen = 0;
405 size_t sz = strlen(cmd);
407 /* --- Make sure that I can get the exit status of children --- */
409 signal(SIGCHLD, SIG_DFL);
411 /* --- Fix up the environment --- */
417 if (env != environ) {
419 env_import(&t, environ);
421 env_put(&t, "SW_ARCH", ARCH);
422 env_file(&t, DATADIR "/sw-env");
423 env = env_export(&t);
426 /* --- Dispatch to the command handler --- */
428 for (p = rcmds; p; p = p->next) {
429 if (strncmp(cmd, p->name, sz) == 0) {
430 if (p->name[sz] == 0) {
434 swdie(r, 1, "ambiguous remote command name `%s'", cmd);
440 swdie(r, 1, "unknown remote command name `%s'", cmd);
441 chosen->rcmd(r, argv, env);
444 /*----- Remote invocation -------------------------------------------------*/
446 /* --- @sendargv@ --- *
448 * Arguments: @sw_remote *r@ = pointer to the remote context
449 * @int type@ = packet type to send with
450 * @char *v[]@ = pointer to the array to send
452 * Returns: Zero if OK, nonzero if it failed.
454 * Use: Sends something @argv@-shaped; i.e., an array of strings
455 * terminated by a null pointer.
458 static int sendargv(sw_remote *r, int type, char *v[])
465 d.len++; /* Make the null `real' */
468 e = pksend(r, type, d.buf, d.len);
473 /* --- @snarfargv@ --- *
475 * Arguments: @const char *buf@ = pointer to buffer
476 * @size_t sz@ = size of buffer
478 * Returns: Pointer to argument array (allocated with @malloc@).
480 * Use: Snarfs the null-terminated strings in the buffer and returns
481 * an array of them. The whole lot, strings and array, is
482 * returned in one big chunk allocated from the heap. Note that
483 * this means it's OK to throw the initial buffer away.
486 static char **snarfargv(const char *buf, size_t sz)
488 /* --- Initial setup --- */
495 /* --- Pass one: count the number of arguments --- */
511 /* --- Allocate memory for everything --- */
513 v = xmalloc((c + 1) * sizeof(char *) + sz + 1);
514 q = (char *)(v + c + 1);
517 /* --- Pass two: set up the arrays --- */
539 /* --- @swrsh_remote@ --- *
541 * Arguments: @const char *cmd@ = the command to perform
543 * Returns: Doesn't. Reports an exit status through packet protocol and
546 * Use: Handles the remote end of a remote job invokation.
549 void swrsh_remote(const char *cmd)
552 static char *dummy = 0;
559 /* --- Read packets from the remote host --- */
565 swdie(&r, 1, "error reading packet: %s", strerror(errno));
572 argv = snarfargv(r.buf, r.sz);
577 env = snarfargv(r.buf, r.sz);
583 dir = xstrdup(r.buf);
589 swdie(&r, 1, "internal error: unexpected packet");
594 /* --- Sort out any missing arguments --- */
604 /* --- Run the command --- */
607 remote(&r, cmd, argv, env);
608 CATCH switch (exc_type) {
610 static char msg[] = "\nsw [remote]: not enough memory\n";
611 pksend(&r, PKTYPE_DATA, msg, sizeof(msg) - 1);
615 swdie(&r, 1, "uncaught exception, type = %lx", exc_type);
619 /*----- Starting remote jobs ----------------------------------------------*/
621 /* --- @sigchld@ --- *
623 * Arguments: @int sig@ = the signal number
627 * Use: Catches @SIGCHLD@ and reaps any children that have lost.
630 static void sigchld(int sig)
634 while (waitpid(-1, &status, WNOHANG) > 0) {
635 if (WIFEXITED(status)) {
636 fprintf(stderr, "reap child with exit status %i\n",
637 WEXITSTATUS(status));
638 } else if (WIFSIGNALED(status)) {
639 fprintf(stderr, "reap child killed by signal %s\n",
640 strsignal(WTERMSIG(status)));
642 fprintf(stderr, "reaped bizarre child which is still alive\n");
645 while (waitpid(-1, 0, WNOHANG) > 0)
652 * Arguments: @sw_remote *r@ = remote process block to look after
653 * @const char *host@ = host to run on (0 for this one)
654 * @const char *cmd@ = remote command to run
655 * @char *argv[]@ = arguments to pass on
657 * Returns: Zero if it worked, nonzero if not.
659 * Use: Runs a command on a remote host. The argument array is
660 * mangled to come out OK at the far end. The environment and
661 * current directory are also passed along, and pop out the
662 * other end unmolested.
665 int swrsh(sw_remote *r, const char *host, const char *cmd, char *argv[])
670 /* --- Get a socket pair for communicating with the other end --- */
672 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sk))
675 /* --- Set up a signal handler --- */
679 sa.sa_handler = sigchld;
681 sigemptyset(&sa.sa_mask);
682 sigaction(SIGCHLD, &sa, 0);
686 /* --- Fork off a child to cope with stuff --- */
692 /* --- Handle the child process --- *
694 * If this is a local job, then just loop around inside to handle the
695 * `remote' command. Otherwise crank up `rsh' and pass the command over to
696 * a remote copy of myself.
698 * (Why do I need a separate process for local jobs? I don't really, but
699 * it makes everything much simpler when running multiple jobs at the same
706 /* --- Child end of a local job --- */
709 r->fdin = r->fdout = sk[1];
710 remote(r, cmd, argv, environ);
713 /* --- Local child end of a remote job --- */
722 rsh = getenv("SW_RSH");
725 execlp(rsh, rsh, host, PATH_SW, "--remote", cmd, (char *)0);
728 /* --- I don't expect either to come back --- */
733 /* --- Local sort out of what to do --- *
735 * Either way, I've now got a socket tied to something which speaks my
736 * communication protocol. However, if this is a local job, then I can get
737 * going right away; otherwise, I've got to transmit various bits of
738 * information over the protocol.
741 r->fdin = r->fdout = sk[0];
746 if (!getcwd(buf, sizeof(buf)))
748 sendargv(r, PKTYPE_ARGS, argv);
749 sendargv(r, PKTYPE_ENV, environ);
750 pksend(r, PKTYPE_DIR, buf, strlen(buf) + 1);
751 pksend(r, PKTYPE_GO, 0, 0);
754 /* --- Ready to rock'n'roll --- */
759 /* --- Tidy up if it failed --- */
768 /*----- Subcommands -------------------------------------------------------*/
770 /* --- @swrsh_rsh@ --- */
772 void rsw_rsh(sw_remote *r, char *argv[], char *env[])
778 /* --- Create a pipe --- */
781 swdie(r, 1, "couldn't create pipe: %s", strerror(errno));
783 /* --- Start the child process up --- */
787 swdie(r, 1, "fork failed: %s", strerror(errno));
791 /* --- Use my new environment --- */
793 environ = env; /* Yuk. */
795 /* --- Fiddle with pipe file descriptors --- */
803 /* --- Make sure it doesn't get any input --- */
806 fd = open("/dev/null", O_RDONLY);
812 /* --- Run the program --- */
814 execvp(argv[0], argv);
815 die(1, "couldn't exec `%s': %s", argv[0], strerror(errno));
818 /* --- Read the data from the pipe until it closes --- */
822 ssize_t n = read(pfd[0], r->buf, sizeof(r->buf));
824 swdie(r, 1, "read error: %s", strerror(errno));
828 pksend(r, PKTYPE_DATA, r->buf, n);
832 /* --- Finally, reap the exit status and pass it on --- */
839 swdie(r, 1, "error reaping child: %s", strerror(errno));
844 /* --- @sw_rsh@ --- */
846 int sw_rsh(int argc, char *argv[])
852 /* --- Check the arguments --- */
855 die(1, "Usage: rsh HOST|ARCH COMMAND [ARGS...]");
857 /* --- Translate architecture names into hostnames --- */
859 if (strcmp(argv[1], "-") == 0)
862 archent *a = arch_lookup(argv[1], 0);
865 else if (a->flags & archFlag_home)
871 /* --- Start the remote process --- */
873 if (swrsh(&r, h, "rsh", argv + 2))
874 die(1, "remote shell failed: %s", strerror(errno));
876 /* --- Cope with packets from the remote process --- */
883 die(1, "error reading packet: %s", strerror(errno));
885 write(STDOUT_FILENO, r.buf, r.sz);
891 moan("command exited due to signal: %s", r.buf);
894 moan("command exited with status %i", r.buf[0]);
898 moan("command exited unexpectedly");
901 die(1, "unexpected packet type");
905 /* --- Finished --- */
912 /*----- That's all, folks -------------------------------------------------*/