3 * $Id: sw_rsh.c,v 1.4 1999/06/24 15:51:17 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 1.4 1999/06/24 15:51:17 mdw
33 * Fix signal handlers so they don't corrupt `errno'.
35 * Revision 1.3 1999/06/18 18:58:54 mdw
36 * Signal handling fixes.
38 * Revision 1.2 1999/06/02 17:03:29 mdw
39 * Fix use of `octet' now that mLib includes `bits.h' (as of version 1.3.5
40 * release). Also use the mLib load and store macros rather than doing it
43 * Revision 1.1.1.1 1999/06/02 16:53:34 mdw
48 /*----- Header files ------------------------------------------------------*/
60 #include <sys/types.h>
65 #include <sys/socket.h>
69 extern char **environ;
72 #include <mLib/alloc.h>
73 #include <mLib/bits.h>
74 #include <mLib/dstr.h>
76 #include <mLib/mdwopt.h>
77 #include <mLib/quis.h>
78 #include <mLib/report.h>
87 /*----- Data structures ---------------------------------------------------*/
91 typedef struct pkhead {
96 /*----- Static variables --------------------------------------------------*/
98 static int handler = 0;
99 static rcmd *rcmds = RCMD_LINK;
101 /*----- Packet interface --------------------------------------------------*/
103 /* --- @pksend@ --- *
105 * Arguments: @sw_remote@ = pointer to the remote block
106 * @int type@ = packet type to send
107 * @const void *p@ = pointer to packet data
108 * @size_t sz@ = size of data to send
110 * Returns: Zero if it worked, nonzero otherwise.
112 * Use: Sends a data packet. If the type is `data', then `sz' may be
113 * arbitrarily large and is divided into small eenough chunks.
114 * Otherwise it's an error to send a packet that's too big.
117 int pksend(sw_remote *r, int type, const void *p, size_t sz)
123 /* --- Sort out error conditions --- */
125 if (sz > PKMAX && type != PKTYPE_DATA) {
130 /* --- Main output loop --- */
135 /* --- Set up the packet header --- */
137 chunk = (sz > PKMAX ? PKMAX : sz);
138 STORE16(h.len, chunk);
140 /* --- Write the packet header --- */
143 if (write(r->fdout, &h, PKHEADSZ) < PKHEADSZ) {
149 /* --- Write the payload, if there is one --- *
151 * Maybe the OS won't want to bite it all off in one go.
155 ssize_t n = write(r->fdout, q, chunk);
156 if (n < 0 && errno != EINTR)
171 /* --- @pkrecv@ --- *
173 * Arguments: @sw_remote *r@ = remote block
175 * Returns: Packet type received, or @-1@ for an error.
177 * Use: Receives a packet from the remote host. The packet data is
178 * placed in the block's buffer, the block's packet length is
179 * diddled appropriately.
182 int pkrecv(sw_remote *r)
189 /* --- Read the packet header --- */
194 n = read(r->fdin, p, sz);
195 if (n < 0 && errno != EINTR)
205 /* --- Hack for error messages --- *
207 * If it doesn't look like a valid packet, read a `chunk' and pretend it's
208 * data. This isn't too bad, because all the packet types are control
209 * codes, and are unlikely to be in a textual message.
211 * Normally what happens here is that something sitting before the `sw'
212 * program fails, reports a plain textual error, and exits. Grabbing the
213 * `last gasp' like this, then, traps that error message and allows
214 * something to report it. The rest ought to be completely silent, so I
215 * get an `unexpected eof' and then drop everything.
217 * This is certainly better than the behaviour otherwise, which is an
218 * @E2BIG@ message reported when the packet size is really ASCII
222 if (h.type >= PKTYPE_BOGUS) {
223 memcpy(r->buf, &h, PKHEADSZ);
224 n = read(r->fdin, r->buf + PKHEADSZ, sizeof(r->buf) - PKHEADSZ);
227 r->sz = n + PKHEADSZ;
228 return (PKTYPE_DATA);
231 /* --- Sort out what's going on --- */
242 /* --- Read the packet payload --- */
246 n = read(r->fdin, p, sz);
247 if (n < 0 && errno != EINTR)
260 /*----- Error reporting and exit statuses --------------------------------*/
262 /* --- @swexit@ --- *
264 * Arguments: @sw_remote *r@ = remote context
265 * @int status@ = exit status to return
269 * Use: Reports the exit status via packet protocol and quits.
272 void swexit(sw_remote *r, int status)
274 unsigned char s = status;
275 pksend(r, PKTYPE_STATUS, &s, 1);
279 /* --- @swsignal@ --- *
281 * Arguments: @sw_remote *r@ = remote context
282 * @int sig@ = signal ocurrence to return
286 * Use: Reports a signalled-to-death status via packet protocol and
290 void swsignal(sw_remote *r, int sig)
292 #if defined(HAVE_STRSIGNAL)
293 char *s = strsignal(sig);
294 #elif defined(HAVE__SYS_SIGLIST)
295 char *s = _sys_siglist[sig];
298 sprintf(s, "signal %i", sig);
301 pksend(r, PKTYPE_STATUS, s, strlen(s) + 1);
305 /* --- @swwait@ --- *
307 * Arguments: @sw_remote *r@ = remote context
308 * @int status@ = status answer from @wait@(2)
312 * Use: Reports a child's demise appropriately, and quits.
315 void swwait(sw_remote *r, int status)
317 if (WIFEXITED(status))
318 swexit(r, WEXITSTATUS(status));
319 else if (WIFSIGNALED(status))
320 swsignal(r, WTERMSIG(status));
325 /* --- @swvprintf@ --- *
327 * Arguments: @sw_remote *r@ = remote context
328 * @const char *format@ = format string
329 * @va_list ap@ = things to format
333 * Use: Writes a string to the remote end. This is the low-level bit
337 void swvprintf(sw_remote *r, const char *format, va_list ap)
340 dstr_vputf(&d, format, ap);
341 pksend(r, PKTYPE_DATA, d.buf, d.len);
345 /* --- @swprintf@ --- *
347 * Arguments: @sw_remote *r@ = remote context
348 * @const char *format@ = format string
349 * @...@ = other arguments
353 * Use: Writes a string to the remote end.
356 void swprintf(sw_remote *r, const char *format, ...)
359 va_start(ap, format);
360 swvprintf(r, format, ap);
366 * Arguments: @sw_remote *r@ = remote context
367 * @int status@ = exit status to report
368 * @const char *format@ = format string to fill in
369 * @...@ = other arguments
373 * Use: Reports a message and quits.
376 void swdie(sw_remote *r, int status, const char *format, ...)
381 va_start(ap, format);
382 dstr_putf(&d, "%s [remote]: ", QUIS);
383 dstr_vputf(&d, format, ap);
387 pksend(r, PKTYPE_DATA, d.buf, d.len);
392 /*----- Command handling and dispatch -------------------------------------*/
394 /* --- @remote@ --- *
396 * Arguments: @sw_remote *r@ = pointer to remote block
397 * @const char *cmd@ = command to run
398 * @char *argv[]@ = argument array
399 * @char *env[]@ = environment variables
401 * Returns: Doesn't. Reports an exit status through packet protocol and
404 * Use: Dispatches a remote command. At this point, the two code
405 * paths for local and remote invokation have joined again.
408 static void remote(sw_remote *r, const char *cmd, char *argv[], char *env[])
410 struct rcmd *p, *chosen = 0;
411 size_t sz = strlen(cmd);
413 /* --- Make sure that I can get the exit status of children --- */
415 signal(SIGCHLD, SIG_DFL);
417 /* --- Fix up the environment --- */
423 if (env != environ) {
425 env_import(&t, environ);
427 env_put(&t, "SW_ARCH", ARCH);
428 env_file(&t, DATADIR "/sw-env");
429 env = env_export(&t);
432 /* --- Dispatch to the command handler --- */
434 for (p = rcmds; p; p = p->next) {
435 if (strncmp(cmd, p->name, sz) == 0) {
436 if (p->name[sz] == 0) {
440 swdie(r, 1, "ambiguous remote command name `%s'", cmd);
446 swdie(r, 1, "unknown remote command name `%s'", cmd);
447 chosen->rcmd(r, argv, env);
450 /*----- Remote invocation -------------------------------------------------*/
452 /* --- @sendargv@ --- *
454 * Arguments: @sw_remote *r@ = pointer to the remote context
455 * @int type@ = packet type to send with
456 * @char *v[]@ = pointer to the array to send
458 * Returns: Zero if OK, nonzero if it failed.
460 * Use: Sends something @argv@-shaped; i.e., an array of strings
461 * terminated by a null pointer.
464 static int sendargv(sw_remote *r, int type, char *v[])
471 d.len++; /* Make the null `real' */
474 e = pksend(r, type, d.buf, d.len);
479 /* --- @snarfargv@ --- *
481 * Arguments: @const char *buf@ = pointer to buffer
482 * @size_t sz@ = size of buffer
484 * Returns: Pointer to argument array (allocated with @malloc@).
486 * Use: Snarfs the null-terminated strings in the buffer and returns
487 * an array of them. The whole lot, strings and array, is
488 * returned in one big chunk allocated from the heap. Note that
489 * this means it's OK to throw the initial buffer away.
492 static char **snarfargv(const char *buf, size_t sz)
494 /* --- Initial setup --- */
501 /* --- Pass one: count the number of arguments --- */
517 /* --- Allocate memory for everything --- */
519 v = xmalloc((c + 1) * sizeof(char *) + sz + 1);
520 q = (char *)(v + c + 1);
523 /* --- Pass two: set up the arrays --- */
545 /* --- @swrsh_remote@ --- *
547 * Arguments: @const char *cmd@ = the command to perform
549 * Returns: Doesn't. Reports an exit status through packet protocol and
552 * Use: Handles the remote end of a remote job invokation.
555 void swrsh_remote(const char *cmd)
558 static char *dummy = 0;
565 /* --- Read packets from the remote host --- */
571 swdie(&r, 1, "error reading packet: %s", strerror(errno));
578 argv = snarfargv(r.buf, r.sz);
583 env = snarfargv(r.buf, r.sz);
589 dir = xstrdup(r.buf);
595 swdie(&r, 1, "internal error: unexpected packet");
600 /* --- Sort out any missing arguments --- */
610 /* --- Run the command --- */
613 remote(&r, cmd, argv, env);
614 CATCH switch (exc_type) {
616 static char msg[] = "\nsw [remote]: not enough memory\n";
617 pksend(&r, PKTYPE_DATA, msg, sizeof(msg) - 1);
621 swdie(&r, 1, "uncaught exception, type = %lx", exc_type);
625 /*----- Starting remote jobs ----------------------------------------------*/
627 /* --- @sigchld@ --- *
629 * Arguments: @int sig@ = the signal number
633 * Use: Catches @SIGCHLD@ and reaps any children that have lost.
636 static void sigchld(int sig)
641 while (waitpid(-1, &status, WNOHANG) > 0) {
642 if (WIFEXITED(status)) {
643 fprintf(stderr, "reap child with exit status %i\n",
644 WEXITSTATUS(status));
645 } else if (WIFSIGNALED(status)) {
646 fprintf(stderr, "reap child killed by signal %s\n",
647 strsignal(WTERMSIG(status)));
649 fprintf(stderr, "reaped bizarre child which is still alive\n");
652 while (waitpid(-1, 0, WNOHANG) > 0)
660 * Arguments: @sw_remote *r@ = remote process block to look after
661 * @const char *host@ = host to run on (0 for this one)
662 * @const char *cmd@ = remote command to run
663 * @char *argv[]@ = arguments to pass on
665 * Returns: Zero if it worked, nonzero if not.
667 * Use: Runs a command on a remote host. The argument array is
668 * mangled to come out OK at the far end. The environment and
669 * current directory are also passed along, and pop out the
670 * other end unmolested.
673 int swrsh(sw_remote *r, const char *host, const char *cmd, char *argv[])
678 /* --- Get a socket pair for communicating with the other end --- */
680 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sk))
683 /* --- Set up a signal handler --- */
687 sa.sa_handler = sigchld;
688 sa.sa_flags = SA_NOCLDSTOP;
690 sa.sa_flags |= SA_RESTART;
692 sigemptyset(&sa.sa_mask);
693 sigaction(SIGCHLD, &sa, 0);
697 /* --- Fork off a child to cope with stuff --- */
703 /* --- Handle the child process --- *
705 * If this is a local job, then just loop around inside to handle the
706 * `remote' command. Otherwise crank up `rsh' and pass the command over to
707 * a remote copy of myself.
709 * (Why do I need a separate process for local jobs? I don't really, but
710 * it makes everything much simpler when running multiple jobs at the same
717 /* --- Child end of a local job --- */
720 r->fdin = r->fdout = sk[1];
721 signal(SIGINT, SIG_DFL);
722 signal(SIGQUIT, SIG_DFL);
723 remote(r, cmd, argv, environ);
726 /* --- Local child end of a remote job --- */
735 rsh = getenv("SW_RSH");
738 execlp(rsh, rsh, host, PATH_SW, "--remote", cmd, (char *)0);
741 /* --- I don't expect either to come back --- */
746 /* --- Local sort out of what to do --- *
748 * Either way, I've now got a socket tied to something which speaks my
749 * communication protocol. However, if this is a local job, then I can get
750 * going right away; otherwise, I've got to transmit various bits of
751 * information over the protocol.
754 r->fdin = r->fdout = sk[0];
759 if (!getcwd(buf, sizeof(buf)))
761 sendargv(r, PKTYPE_ARGS, argv);
762 sendargv(r, PKTYPE_ENV, environ);
763 pksend(r, PKTYPE_DIR, buf, strlen(buf) + 1);
764 pksend(r, PKTYPE_GO, 0, 0);
767 /* --- Ready to rock'n'roll --- */
772 /* --- Tidy up if it failed --- */
781 /*----- Subcommands -------------------------------------------------------*/
783 /* --- @swrsh_rsh@ --- */
785 void rsw_rsh(sw_remote *r, char *argv[], char *env[])
791 /* --- Create a pipe --- */
794 swdie(r, 1, "couldn't create pipe: %s", strerror(errno));
796 /* --- Start the child process up --- */
800 swdie(r, 1, "fork failed: %s", strerror(errno));
804 /* --- Use my new environment --- */
806 environ = env; /* Yuk. */
808 /* --- Fiddle with pipe file descriptors --- */
816 /* --- Make sure it doesn't get any input --- */
819 fd = open("/dev/null", O_RDONLY);
825 /* --- Run the program --- */
827 execvp(argv[0], argv);
828 die(1, "couldn't exec `%s': %s", argv[0], strerror(errno));
831 /* --- Read the data from the pipe until it closes --- */
835 ssize_t n = read(pfd[0], r->buf, sizeof(r->buf));
837 swdie(r, 1, "read error: %s", strerror(errno));
841 pksend(r, PKTYPE_DATA, r->buf, n);
845 /* --- Finally, reap the exit status and pass it on --- */
852 swdie(r, 1, "error reaping child: %s", strerror(errno));
857 /* --- @sw_rsh@ --- */
859 int sw_rsh(int argc, char *argv[])
865 /* --- Check the arguments --- */
868 die(1, "Usage: rsh HOST|ARCH COMMAND [ARGS...]");
870 /* --- Translate architecture names into hostnames --- */
872 if (strcmp(argv[1], "-") == 0)
875 archent *a = arch_lookup(argv[1], 0);
878 else if (a->flags & archFlag_home)
884 /* --- Start the remote process --- */
886 if (swrsh(&r, h, "rsh", argv + 2))
887 die(1, "remote shell failed: %s", strerror(errno));
889 /* --- Cope with packets from the remote process --- */
896 die(1, "error reading packet: %s", strerror(errno));
898 write(STDOUT_FILENO, r.buf, r.sz);
904 moan("command exited due to signal: %s", r.buf);
907 moan("command exited with status %i", r.buf[0]);
911 moan("command exited unexpectedly");
914 die(1, "unexpected packet type");
918 /* --- Finished --- */
925 /*----- That's all, folks -------------------------------------------------*/