If we're making backups with --inplace, use the backup file as the
[rsync.git] / main.c
1 /* -*- c-file-style: "linux" -*-
2
3    Copyright (C) 1996-2001 by Andrew Tridgell <tridge@samba.org>
4    Copyright (C) Paul Mackerras 1996
5    Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
6
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software
19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22 #include "rsync.h"
23
24 time_t starttime = 0;
25
26 extern struct stats stats;
27 extern int am_root;
28 extern int am_server;
29 extern int am_sender;
30 extern int am_generator;
31 extern int am_daemon;
32 extern int verbose;
33 extern int blocking_io;
34 extern int cvs_exclude;
35 extern int delete_mode;
36 extern int delete_excluded;
37 extern int delete_after;
38 extern int daemon_over_rsh;
39 extern int do_stats;
40 extern int dry_run;
41 extern int list_only;
42 extern int local_server;
43 extern int log_got_error;
44 extern int module_id;
45 extern int orig_umask;
46 extern int copy_links;
47 extern int keep_dirlinks;
48 extern int preserve_hard_links;
49 extern int protocol_version;
50 extern int recurse;
51 extern int relative_paths;
52 extern int rsync_port;
53 extern int whole_file;
54 extern int read_batch;
55 extern int write_batch;
56 extern int batch_fd;
57 extern int batch_gen_fd;
58 extern int filesfrom_fd;
59 extern pid_t cleanup_child_pid;
60 extern char *files_from;
61 extern char *remote_filesfrom_file;
62 extern char *rsync_path;
63 extern char *shell_cmd;
64 extern char *batch_name;
65
66
67 /* there's probably never more than at most 2 outstanding child processes,
68  * but set it higher just in case.
69  */
70 #define MAXCHILDPROCS 5
71
72 struct pid_status {
73         pid_t pid;
74         int   status;
75 } pid_stat_table[MAXCHILDPROCS];
76
77 static void show_malloc_stats(void);
78
79 /****************************************************************************
80 wait for a process to exit, calling io_flush while waiting
81 ****************************************************************************/
82 void wait_process(pid_t pid, int *status)
83 {
84         pid_t waited_pid;
85         int cnt;
86
87         while ((waited_pid = waitpid(pid, status, WNOHANG)) == 0) {
88                 msleep(20);
89                 io_flush(FULL_FLUSH);
90         }
91
92         if (waited_pid == -1 && errno == ECHILD) {
93                 /* status of requested child no longer available.
94                  * check to see if it was processed by the sigchld_handler.
95                  */
96                 for (cnt = 0;  cnt < MAXCHILDPROCS; cnt++) {
97                         if (pid == pid_stat_table[cnt].pid) {
98                                 *status = pid_stat_table[cnt].status;
99                                 pid_stat_table[cnt].pid = 0;
100                                 break;
101                         }
102                 }
103         }
104
105         /* TODO: If the child exited on a signal, then log an
106          * appropriate error message.  Perhaps we should also accept a
107          * message describing the purpose of the child.  Also indicate
108          * this to the caller so that thhey know something went
109          * wrong.  */
110         *status = WEXITSTATUS(*status);
111 }
112
113 /* This function gets called from all 3 processes.  We want the client side
114  * to actually output the text, but the sender is the only process that has
115  * all the stats we need.  So, if we're a client sender, we do the report.
116  * If we're a server sender, we write the stats on the supplied fd.  If
117  * we're the client receiver we read the stats from the supplied fd and do
118  * the report.  All processes might also generate a set of debug stats, if
119  * the verbose level is high enough (this is the only thing that the
120  * generator process and the server receiver ever do here). */
121 static void report(int f)
122 {
123         /* Cache two stats because the read/write code can change it. */
124         int64 total_read = stats.total_read;
125         int64 total_written = stats.total_written;
126         time_t t = time(NULL);
127
128         if (do_stats && verbose > 1) {
129                 /* These come out from every process */
130                 show_malloc_stats();
131                 show_flist_stats();
132         }
133
134         if (am_generator)
135                 return;
136
137         if (am_daemon) {
138                 log_exit(0, __FILE__, __LINE__);
139                 if (f == -1 || !am_sender)
140                         return;
141         }
142
143         if (am_server) {
144                 if (am_sender) {
145                         write_longint(f, total_read);
146                         write_longint(f, total_written);
147                         write_longint(f, stats.total_size);
148                 }
149                 return;
150         }
151
152         /* this is the client */
153
154         if (!am_sender) {
155                 /* Read the first two in opposite order because the meaning of
156                  * read/write swaps when switching from sender to receiver. */
157                 total_written = read_longint(f);
158                 total_read = read_longint(f);
159                 stats.total_size = read_longint(f);
160         } else if (write_batch) {
161                 /* The --read-batch process is going to be a client
162                  * receiver, so we need to give it the stats. */
163                 write_longint(batch_fd, total_read);
164                 write_longint(batch_fd, total_written);
165                 write_longint(batch_fd, stats.total_size);
166         }
167
168         if (do_stats) {
169                 rprintf(FINFO,"\nNumber of files: %d\n", stats.num_files);
170                 rprintf(FINFO,"Number of files transferred: %d\n",
171                         stats.num_transferred_files);
172                 rprintf(FINFO,"Total file size: %.0f bytes\n",
173                         (double)stats.total_size);
174                 rprintf(FINFO,"Total transferred file size: %.0f bytes\n",
175                         (double)stats.total_transferred_size);
176                 rprintf(FINFO,"Literal data: %.0f bytes\n",
177                         (double)stats.literal_data);
178                 rprintf(FINFO,"Matched data: %.0f bytes\n",
179                         (double)stats.matched_data);
180                 rprintf(FINFO,"File list size: %d\n", stats.flist_size);
181                 rprintf(FINFO,"Total bytes sent: %.0f\n",
182                         (double)total_written);
183                 rprintf(FINFO,"Total bytes received: %.0f\n",
184                         (double)total_read);
185         }
186
187         if (verbose || do_stats) {
188                 rprintf(FINFO,
189                         "\nsent %.0f bytes  received %.0f bytes  %.2f bytes/sec\n",
190                         (double)total_written, (double)total_read,
191                         (total_written + total_read)/(0.5 + (t - starttime)));
192                 rprintf(FINFO, "total size is %.0f  speedup is %.2f\n",
193                         (double)stats.total_size,
194                         (double)stats.total_size / (total_written+total_read));
195         }
196
197         fflush(stdout);
198         fflush(stderr);
199 }
200
201
202 /**
203  * If our C library can get malloc statistics, then show them to FINFO
204  **/
205 static void show_malloc_stats(void)
206 {
207 #ifdef HAVE_MALLINFO
208         struct mallinfo mi;
209
210         mi = mallinfo();
211
212         rprintf(FINFO, "\n" RSYNC_NAME "[%d] (%s%s%s) heap statistics:\n",
213                 getpid(),
214                 am_server ? "server " : "",
215                 am_daemon ? "daemon " : "",
216                 who_am_i());
217         rprintf(FINFO, "  arena:     %10d   (bytes from sbrk)\n", mi.arena);
218         rprintf(FINFO, "  ordblks:   %10d   (chunks not in use)\n", mi.ordblks);
219         rprintf(FINFO, "  smblks:    %10d\n", mi.smblks);
220         rprintf(FINFO, "  hblks:     %10d   (chunks from mmap)\n", mi.hblks);
221         rprintf(FINFO, "  hblkhd:    %10d   (bytes from mmap)\n", mi.hblkhd);
222         rprintf(FINFO, "  allmem:    %10d   (bytes from sbrk + mmap)\n",
223             mi.arena + mi.hblkhd);
224         rprintf(FINFO, "  usmblks:   %10d\n", mi.usmblks);
225         rprintf(FINFO, "  fsmblks:   %10d\n", mi.fsmblks);
226         rprintf(FINFO, "  uordblks:  %10d   (bytes used)\n", mi.uordblks);
227         rprintf(FINFO, "  fordblks:  %10d   (bytes free)\n", mi.fordblks);
228         rprintf(FINFO, "  keepcost:  %10d   (bytes in releasable chunk)\n", mi.keepcost);
229 #endif /* HAVE_MALLINFO */
230 }
231
232
233 /* Start the remote shell.   cmd may be NULL to use the default. */
234 static pid_t do_cmd(char *cmd, char *machine, char *user, char *path,
235                     int *f_in, int *f_out)
236 {
237         int i, argc = 0;
238         char *args[MAX_ARGS];
239         pid_t ret;
240         char *tok, *dir = NULL;
241         int dash_l_set = 0;
242
243         if (!read_batch && !local_server) {
244                 char *rsh_env = getenv(RSYNC_RSH_ENV);
245                 if (!cmd)
246                         cmd = rsh_env;
247                 if (!cmd)
248                         cmd = RSYNC_RSH;
249                 cmd = strdup(cmd);
250                 if (!cmd)
251                         goto oom;
252
253                 for (tok = strtok(cmd, " "); tok; tok = strtok(NULL, " ")) {
254                         /* Comparison leaves rooms for server_options(). */
255                         if (argc >= MAX_ARGS - 100) {
256                                 rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
257                                 exit_cleanup(RERR_SYNTAX);
258                         }
259                         args[argc++] = tok;
260                 }
261
262                 /* check to see if we've already been given '-l user' in
263                  * the remote-shell command */
264                 for (i = 0; i < argc-1; i++) {
265                         if (!strcmp(args[i], "-l") && args[i+1][0] != '-')
266                                 dash_l_set = 1;
267                 }
268
269 #if HAVE_REMSH
270                 /* remsh (on HPUX) takes the arguments the other way around */
271                 args[argc++] = machine;
272                 if (user && !(daemon_over_rsh && dash_l_set)) {
273                         args[argc++] = "-l";
274                         args[argc++] = user;
275                 }
276 #else
277                 if (user && !(daemon_over_rsh && dash_l_set)) {
278                         args[argc++] = "-l";
279                         args[argc++] = user;
280                 }
281                 args[argc++] = machine;
282 #endif
283
284                 args[argc++] = rsync_path;
285
286                 if (blocking_io < 0) {
287                         char *cp;
288                         if ((cp = strrchr(cmd, '/')) != NULL)
289                                 cp++;
290                         else
291                                 cp = cmd;
292                         if (strcmp(cp, "rsh") == 0 || strcmp(cp, "remsh") == 0)
293                                 blocking_io = 1;
294                 }
295
296                 server_options(args,&argc);
297
298                 if (argc >= MAX_ARGS - 2) {
299                         rprintf(FERROR, "internal: args[] overflowed in do_cmd()\n");
300                         exit_cleanup(RERR_SYNTAX);
301                 }
302         }
303
304         args[argc++] = ".";
305
306         if (!daemon_over_rsh && path && *path)
307                 args[argc++] = path;
308
309         args[argc] = NULL;
310
311         if (verbose > 3) {
312                 rprintf(FINFO,"cmd=");
313                 for (i = 0; i < argc; i++)
314                         rprintf(FINFO,"%s ",args[i]);
315                 rprintf(FINFO,"\n");
316         }
317
318         if (read_batch) {
319                 int from_gen_pipe[2];
320                 if (fd_pair(from_gen_pipe) < 0) {
321                         rsyserr(FERROR, errno, "pipe");
322                         exit_cleanup(RERR_IPC);
323                 }
324                 batch_gen_fd = from_gen_pipe[0];
325                 *f_out = from_gen_pipe[1];
326                 *f_in = batch_fd;
327                 ret = -1; /* no child pid */
328         } else if (local_server) {
329                 /* If the user didn't request --[no-]whole-file, force
330                  * it on, but only if we're not batch processing. */
331                 if (whole_file < 0 && !write_batch)
332                         whole_file = 1;
333                 ret = local_child(argc, args, f_in, f_out, child_main);
334         } else
335                 ret = piped_child(args,f_in,f_out);
336
337         if (dir)
338                 free(dir);
339
340         return ret;
341
342 oom:
343         out_of_memory("do_cmd");
344         return 0; /* not reached */
345 }
346
347
348 static char *get_local_name(struct file_list *flist,char *name)
349 {
350         STRUCT_STAT st;
351         int e;
352
353         if (verbose > 2)
354                 rprintf(FINFO,"get_local_name count=%d %s\n",
355                         flist->count, NS(name));
356
357         if (!name)
358                 return NULL;
359
360         if (do_stat(name,&st) == 0) {
361                 if (S_ISDIR(st.st_mode)) {
362                         if (!push_dir(name)) {
363                                 rsyserr(FERROR, errno, "push_dir#1 %s failed",
364                                         full_fname(name));
365                                 exit_cleanup(RERR_FILESELECT);
366                         }
367                         return NULL;
368                 }
369                 if (flist->count > 1) {
370                         rprintf(FERROR,"ERROR: destination must be a directory when copying more than 1 file\n");
371                         exit_cleanup(RERR_FILESELECT);
372                 }
373                 return name;
374         }
375
376         if (flist->count <= 1 && ((e = strlen(name)) <= 1 || name[e-1] != '/'))
377                 return name;
378
379         if (do_mkdir(name,0777 & ~orig_umask) != 0) {
380                 rsyserr(FERROR, errno, "mkdir %s failed", full_fname(name));
381                 exit_cleanup(RERR_FILEIO);
382         }
383         if (verbose > 0)
384                 rprintf(FINFO, "created directory %s\n", name);
385
386         if (dry_run) {
387                 dry_run++;
388                 return NULL;
389         }
390
391         if (!push_dir(name)) {
392                 rsyserr(FERROR, errno, "push_dir#2 %s failed",
393                         full_fname(name));
394                 exit_cleanup(RERR_FILESELECT);
395         }
396
397         return NULL;
398 }
399
400
401 static void do_server_sender(int f_in, int f_out, int argc,char *argv[])
402 {
403         int i;
404         struct file_list *flist;
405         char *dir = argv[0];
406
407         if (verbose > 2) {
408                 rprintf(FINFO, "server_sender starting pid=%ld\n",
409                         (long)getpid());
410         }
411
412         if (am_daemon && lp_write_only(module_id)) {
413                 rprintf(FERROR, "ERROR: module is write only\n");
414                 exit_cleanup(RERR_SYNTAX);
415                 return;
416         }
417
418         if (!relative_paths && !push_dir(dir)) {
419                 rsyserr(FERROR, errno, "push_dir#3 %s failed",
420                         full_fname(dir));
421                 exit_cleanup(RERR_FILESELECT);
422         }
423         argc--;
424         argv++;
425
426         if (strcmp(dir,".")) {
427                 int l = strlen(dir);
428                 if (strcmp(dir,"/") == 0)
429                         l = 0;
430                 for (i = 0; i < argc; i++)
431                         argv[i] += l+1;
432         }
433
434         if (argc == 0 && recurse) {
435                 argc = 1;
436                 argv--;
437                 argv[0] = ".";
438         }
439
440         flist = send_file_list(f_out,argc,argv);
441         if (!flist || flist->count == 0) {
442                 exit_cleanup(0);
443         }
444
445         io_start_buffering_in();
446         io_start_buffering_out();
447
448         send_files(flist,f_out,f_in);
449         io_flush(FULL_FLUSH);
450         report(f_out);
451         if (protocol_version >= 24) {
452                 /* final goodbye message */
453                 read_int(f_in);
454         }
455         io_flush(FULL_FLUSH);
456         exit_cleanup(0);
457 }
458
459
460 static int do_recv(int f_in,int f_out,struct file_list *flist,char *local_name)
461 {
462         int pid;
463         int status = 0;
464         int error_pipe[2];
465
466         /* The receiving side mustn't obey this, or an existing symlink that
467          * points to an identical file won't be replaced by the referent. */
468         copy_links = 0;
469
470         if (preserve_hard_links)
471                 init_hard_links(flist);
472
473         if (!delete_after) {
474                 /* I moved this here from recv_files() to prevent a race condition */
475                 if (recurse && delete_mode && !local_name && flist->count > 0)
476                         delete_files(flist);
477         }
478
479         if (fd_pair(error_pipe) < 0) {
480                 rprintf(FERROR,"error pipe failed in do_recv\n");
481                 exit_cleanup(RERR_SOCKETIO);
482         }
483
484         io_flush(NORMAL_FLUSH);
485
486         if ((pid = do_fork()) == 0) {
487                 close(error_pipe[0]);
488                 if (f_in != f_out)
489                         close(f_out);
490
491                 /* we can't let two processes write to the socket at one time */
492                 close_multiplexing_out();
493
494                 /* set place to send errors */
495                 set_msg_fd_out(error_pipe[1]);
496
497                 recv_files(f_in,flist,local_name);
498                 io_flush(FULL_FLUSH);
499                 report(f_in);
500
501                 send_msg(MSG_DONE, "", 0);
502                 io_flush(FULL_FLUSH);
503                 /* finally we go to sleep until our parent kills us
504                  * with a USR2 signal. We sleep for a short time as on
505                  * some OSes a signal won't interrupt a sleep! */
506                 while (1)
507                         msleep(20);
508         }
509
510         am_generator = 1;
511         close_multiplexing_in();
512         if (write_batch)
513                 stop_write_batch();
514
515         close(error_pipe[1]);
516         if (f_in != f_out)
517                 close(f_in);
518
519         io_start_buffering_out();
520
521         set_msg_fd_in(error_pipe[0]);
522
523         generate_files(f_out, flist, local_name);
524
525         get_redo_num(); /* Read final MSG_DONE and any prior messages. */
526         report(-1);
527         io_flush(FULL_FLUSH);
528         if (protocol_version >= 24) {
529                 /* send a final goodbye message */
530                 write_int(f_out, -1);
531         }
532         io_flush(FULL_FLUSH);
533
534         set_msg_fd_in(-1);
535         kill(pid, SIGUSR2);
536         wait_process(pid, &status);
537         return status;
538 }
539
540
541 static void do_server_recv(int f_in, int f_out, int argc,char *argv[])
542 {
543         int status;
544         struct file_list *flist;
545         char *local_name = NULL;
546         char *dir = NULL;
547
548         if (verbose > 2) {
549                 rprintf(FINFO, "server_recv(%d) starting pid=%ld\n",
550                         argc, (long)getpid());
551         }
552
553         if (am_daemon && lp_read_only(module_id)) {
554                 rprintf(FERROR,"ERROR: module is read only\n");
555                 exit_cleanup(RERR_SYNTAX);
556                 return;
557         }
558
559
560         if (argc > 0) {
561                 dir = argv[0];
562                 argc--;
563                 argv++;
564                 if (!am_daemon && !push_dir(dir)) {
565                         rsyserr(FERROR, errno, "push_dir#4 %s failed",
566                                 full_fname(dir));
567                         exit_cleanup(RERR_FILESELECT);
568                 }
569         }
570
571         io_start_buffering_in();
572         if (delete_mode && !delete_excluded)
573                 recv_exclude_list(f_in);
574
575         if (filesfrom_fd >= 0) {
576                 /* We're receiving the file info from the sender, so we need
577                  * the IO routines to automatically write out the names onto
578                  * our f_out socket as we read the list info from the sender.
579                  * This avoids both deadlock and extra delays/buffers. */
580                 io_set_filesfrom_fds(filesfrom_fd, f_out);
581                 filesfrom_fd = -1;
582         }
583
584         flist = recv_file_list(f_in);
585         if (!flist) {
586                 rprintf(FERROR,"server_recv: recv_file_list error\n");
587                 exit_cleanup(RERR_FILESELECT);
588         }
589
590         if (argc > 0) {
591                 if (strcmp(dir,".")) {
592                         argv[0] += strlen(dir);
593                         if (argv[0][0] == '/')
594                                 argv[0]++;
595                 }
596                 local_name = get_local_name(flist,argv[0]);
597         }
598
599         status = do_recv(f_in,f_out,flist,local_name);
600         exit_cleanup(status);
601 }
602
603
604 int child_main(int argc, char *argv[])
605 {
606         start_server(STDIN_FILENO, STDOUT_FILENO, argc, argv);
607         return 0;
608 }
609
610
611 void start_server(int f_in, int f_out, int argc, char *argv[])
612 {
613         set_nonblocking(f_in);
614         set_nonblocking(f_out);
615
616         io_set_sock_fds(f_in, f_out);
617         setup_protocol(f_out, f_in);
618
619         if (protocol_version >= 23)
620                 io_start_multiplex_out();
621
622         if (am_sender) {
623                 keep_dirlinks = 0; /* Must be disabled on the sender. */
624
625                 recv_exclude_list(f_in);
626                 if (cvs_exclude)
627                         add_cvs_excludes();
628                 do_server_sender(f_in, f_out, argc, argv);
629         } else {
630                 do_server_recv(f_in, f_out, argc, argv);
631         }
632         exit_cleanup(0);
633 }
634
635
636 /*
637  * This is called once the connection has been negotiated.  It is used
638  * for rsyncd, remote-shell, and local connections.
639  */
640 int client_run(int f_in, int f_out, pid_t pid, int argc, char *argv[])
641 {
642         struct file_list *flist = NULL;
643         int status = 0, status2 = 0;
644         char *local_name = NULL;
645
646         cleanup_child_pid = pid;
647         if (read_batch) {
648                 assert(am_sender == 0);
649         } else {
650                 set_nonblocking(f_in);
651                 set_nonblocking(f_out);
652         }
653
654         io_set_sock_fds(f_in, f_out);
655         setup_protocol(f_out,f_in);
656
657         if (protocol_version >= 23 && !read_batch)
658                 io_start_multiplex_in();
659
660         if (am_sender) {
661                 keep_dirlinks = 0; /* Must be disabled on the sender. */
662                 io_start_buffering_out();
663                 if (cvs_exclude)
664                         add_cvs_excludes();
665                 if (delete_mode && !delete_excluded)
666                         send_exclude_list(f_out);
667                 if (remote_filesfrom_file)
668                         filesfrom_fd = f_in;
669
670                 if (write_batch)
671                         start_write_batch(f_out);
672                 if (!read_batch) /* don't write to pipe */
673                         flist = send_file_list(f_out,argc,argv);
674                 if (verbose > 3)
675                         rprintf(FINFO,"file list sent\n");
676
677                 io_flush(NORMAL_FLUSH);
678                 send_files(flist,f_out,f_in);
679                 io_flush(FULL_FLUSH);
680                 if (protocol_version >= 24) {
681                         /* final goodbye message */
682                         read_int(f_in);
683                 }
684                 if (pid != -1) {
685                         if (verbose > 3)
686                                 rprintf(FINFO,"client_run waiting on %d\n", (int) pid);
687                         io_flush(FULL_FLUSH);
688                         wait_process(pid, &status);
689                 }
690                 report(-1);
691                 io_flush(FULL_FLUSH);
692                 exit_cleanup(status);
693         }
694
695         if (argc == 0)
696                 list_only = 1;
697
698         if (!read_batch)
699                 send_exclude_list(f_out);
700
701         if (filesfrom_fd >= 0) {
702                 io_set_filesfrom_fds(filesfrom_fd, f_out);
703                 filesfrom_fd = -1;
704         }
705
706         if (write_batch)
707                 start_write_batch(f_in);
708         flist = recv_file_list(f_in);
709         if (!flist || flist->count == 0) {
710                 rprintf(FINFO, "client: nothing to do: "
711                         "perhaps you need to specify some filenames or "
712                         "the --recursive option?\n");
713                 exit_cleanup(0);
714         }
715
716         local_name = get_local_name(flist,argv[0]);
717
718         status2 = do_recv(f_in,f_out,flist,local_name);
719
720         if (pid != -1) {
721                 if (verbose > 3)
722                         rprintf(FINFO,"client_run2 waiting on %d\n", (int) pid);
723                 io_flush(FULL_FLUSH);
724                 wait_process(pid, &status);
725         }
726
727         return MAX(status, status2);
728 }
729
730 static int copy_argv (char *argv[])
731 {
732         int i;
733
734         for (i = 0; argv[i]; i++) {
735                 if (!(argv[i] = strdup(argv[i]))) {
736                         rprintf (FERROR, "out of memory at %s(%d)\n",
737                                  __FILE__, __LINE__);
738                         return RERR_MALLOC;
739                 }
740         }
741
742         return 0;
743 }
744
745
746 /**
747  * Start a client for either type of remote connection.  Work out
748  * whether the arguments request a remote shell or rsyncd connection,
749  * and call the appropriate connection function, then run_client.
750  *
751  * Calls either start_socket_client (for sockets) or do_cmd and
752  * client_run (for ssh).
753  **/
754 static int start_client(int argc, char *argv[])
755 {
756         char *p;
757         char *shell_machine = NULL;
758         char *shell_path = NULL;
759         char *shell_user = NULL;
760         int ret;
761         pid_t pid;
762         int f_in,f_out;
763         int rc;
764
765         /* Don't clobber argv[] so that ps(1) can still show the right
766          * command line. */
767         if ((rc = copy_argv(argv)))
768                 return rc;
769
770         /* rsync:// always uses rsync server over direct socket connection */
771         if (strncasecmp(URL_PREFIX, argv[0], strlen(URL_PREFIX)) == 0
772             && !read_batch) {
773                 char *host, *path;
774
775                 host = argv[0] + strlen(URL_PREFIX);
776                 p = strchr(host,'/');
777                 if (p) {
778                         *p = 0;
779                         path = p+1;
780                 } else {
781                         path = "";
782                 }
783                 p = strchr(host,':');
784                 if (p) {
785                         rsync_port = atoi(p+1);
786                         *p = 0;
787                 }
788                 return start_socket_client(host, path, argc-1, argv+1);
789         }
790
791         if (!read_batch) { /* for read_batch, NO source is specified */
792                 p = find_colon(argv[0]);
793                 if (p) { /* source is remote */
794                         if (remote_filesfrom_file
795                          && remote_filesfrom_file != files_from + 1
796                          && strncmp(files_from, argv[0], p-argv[0]+1) != 0) {
797                                 rprintf(FERROR,
798                                         "--files-from hostname is not transfer hostname\n");
799                                 exit_cleanup(RERR_SYNTAX);
800                         }
801                         if (p[1] == ':') { /* double colon */
802                                 *p = 0;
803                                 if (!shell_cmd) {
804                                         return start_socket_client(argv[0], p+2,
805                                                                    argc-1, argv+1);
806                                 }
807                                 p++;
808                                 daemon_over_rsh = 1;
809                         }
810
811                         if (argc < 1) { /* destination required */
812                                 usage(FERROR);
813                                 exit_cleanup(RERR_SYNTAX);
814                         }
815
816                         am_sender = 0;
817                         *p = 0;
818                         shell_machine = argv[0];
819                         shell_path = p+1;
820                         argv++;
821                 } else { /* source is local */
822                         am_sender = 1;
823
824                         /* rsync:// destination uses rsync server over direct socket */
825                         if (strncasecmp(URL_PREFIX, argv[argc-1], strlen(URL_PREFIX)) == 0) {
826                                 char *host, *path;
827
828                                 host = argv[argc-1] + strlen(URL_PREFIX);
829                                 p = strchr(host,'/');
830                                 if (p) {
831                                         *p = 0;
832                                         path = p+1;
833                                 } else {
834                                         path = "";
835                                 }
836                                 p = strchr(host,':');
837                                 if (p) {
838                                         rsync_port = atoi(p+1);
839                                         *p = 0;
840                                 }
841                                 return start_socket_client(host, path, argc-1, argv);
842                         }
843
844                         p = find_colon(argv[argc-1]); /* look in dest arg */
845                         if (p && remote_filesfrom_file
846                          && remote_filesfrom_file != files_from + 1
847                          && strncmp(files_from, argv[argc-1], p-argv[argc-1]+1) != 0) {
848                                 rprintf(FERROR,
849                                         "--files-from hostname is not transfer hostname\n");
850                                 exit_cleanup(RERR_SYNTAX);
851                         }
852                         if (!p) { /* no colon found, so src & dest are local */
853                                 local_server = 1;
854                                 if (remote_filesfrom_file) {
855                                         rprintf(FERROR,
856                                                 "--files-from is remote but transfer is local\n");
857                                         exit_cleanup(RERR_SYNTAX);
858                                 }
859                         } else if (p[1] == ':') { /* double colon */
860                                 *p = 0;
861                                 if (!shell_cmd) {
862                                         return start_socket_client(argv[argc-1], p+2,
863                                                                    argc-1, argv);
864                                 }
865                                 p++;
866                                 daemon_over_rsh = 1;
867                         }
868
869                         if (argc < 2) {
870                                 usage(FERROR);
871                                 exit_cleanup(RERR_SYNTAX);
872                         }
873
874                         if (local_server) {
875                                 shell_machine = NULL;
876                                 shell_path = argv[argc-1];
877                         } else {
878                                 *p = 0;
879                                 shell_machine = argv[argc-1];
880                                 shell_path = p+1;
881                         }
882                 }
883                 argc--;
884         } else {  /* read_batch */
885                 local_server = 1;
886                 shell_path = argv[argc-1];
887                 if (find_colon(shell_path)) {
888                         rprintf(FERROR, "remote destination is not allowed with --read-batch\n");
889                         exit_cleanup(RERR_SYNTAX);
890                 }
891         }
892
893         if (shell_machine) {
894                 p = strrchr(shell_machine,'@');
895                 if (p) {
896                         *p = 0;
897                         shell_user = shell_machine;
898                         shell_machine = p+1;
899                 }
900         }
901
902         if (verbose > 3) {
903                 rprintf(FINFO,"cmd=%s machine=%s user=%s path=%s\n",
904                         shell_cmd?shell_cmd:"",
905                         shell_machine?shell_machine:"",
906                         shell_user?shell_user:"",
907                         shell_path?shell_path:"");
908         }
909
910         /* for remote source, only single dest arg can remain ... */
911         if (!am_sender && argc > 1) {
912                 usage(FERROR);
913                 exit_cleanup(RERR_SYNTAX);
914         }
915
916         /* ... or no dest at all */
917         if (!am_sender && argc == 0) {
918                 list_only = 1;
919         }
920
921         pid = do_cmd(shell_cmd,shell_machine,shell_user,shell_path,
922                      &f_in,&f_out);
923
924         /* if we're running an rsync server on the remote host over a
925          * remote shell command, we need to do the RSYNCD protocol first */
926         if (daemon_over_rsh) {
927                 int tmpret;
928                 tmpret = start_inband_exchange(shell_user, shell_path,
929                                                f_in, f_out, argc);
930                 if (tmpret < 0)
931                         return tmpret;
932         }
933
934         ret = client_run(f_in, f_out, pid, argc, argv);
935
936         fflush(stdout);
937         fflush(stderr);
938
939         return ret;
940 }
941
942
943 static RETSIGTYPE sigusr1_handler(UNUSED(int val))
944 {
945         exit_cleanup(RERR_SIGNAL);
946 }
947
948 static RETSIGTYPE sigusr2_handler(UNUSED(int val))
949 {
950         if (log_got_error) _exit(RERR_PARTIAL);
951         _exit(0);
952 }
953
954 static RETSIGTYPE sigchld_handler(UNUSED(int val))
955 {
956 #ifdef WNOHANG
957         int cnt, status;
958         pid_t pid;
959         /* An empty waitpid() loop was put here by Tridge and we could never
960          * get him to explain why he put it in, so rather than taking it
961          * out we're instead saving the child exit statuses for later use.
962          * The waitpid() loop presumably eliminates all possibility of leaving
963          * zombie children, maybe that's why he did it.
964          */
965         while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
966                 /* save the child's exit status */
967                 for (cnt = 0; cnt < MAXCHILDPROCS; cnt++) {
968                         if (pid_stat_table[cnt].pid == 0) {
969                                 pid_stat_table[cnt].pid = pid;
970                                 pid_stat_table[cnt].status = status;
971                                 break;
972                         }
973                 }
974         }
975 #endif
976 }
977
978
979 /**
980  * This routine catches signals and tries to send them to gdb.
981  *
982  * Because it's called from inside a signal handler it ought not to
983  * use too many library routines.
984  *
985  * @todo Perhaps use "screen -X" instead/as well, to help people
986  * debugging without easy access to X.  Perhaps use an environment
987  * variable, or just call a script?
988  *
989  * @todo The /proc/ magic probably only works on Linux (and
990  * Solaris?)  Can we be more portable?
991  **/
992 #ifdef MAINTAINER_MODE
993 const char *get_panic_action(void)
994 {
995         const char *cmd_fmt = getenv("RSYNC_PANIC_ACTION");
996
997         if (cmd_fmt)
998                 return cmd_fmt;
999         else
1000                 return "xterm -display :0 -T Panic -n Panic "
1001                         "-e gdb /proc/%d/exe %d";
1002 }
1003
1004
1005 /**
1006  * Handle a fatal signal by launching a debugger, controlled by $RSYNC_PANIC_ACTION.
1007  *
1008  * This signal handler is only installed if we were configured with
1009  * --enable-maintainer-mode.  Perhaps it should always be on and we
1010  * should just look at the environment variable, but I'm a bit leery
1011  * of a signal sending us into a busy loop.
1012  **/
1013 static RETSIGTYPE rsync_panic_handler(UNUSED(int whatsig))
1014 {
1015         char cmd_buf[300];
1016         int ret;
1017
1018         sprintf(cmd_buf, get_panic_action(),
1019                 getpid(), getpid());
1020
1021         /* Unless we failed to execute gdb, we allow the process to
1022          * continue.  I'm not sure if that's right. */
1023         ret = system(cmd_buf);
1024         if (ret)
1025                 _exit(ret);
1026 }
1027 #endif
1028
1029
1030 int main(int argc,char *argv[])
1031 {
1032         int ret;
1033         int orig_argc = argc;
1034         char **orig_argv = argv;
1035
1036         signal(SIGUSR1, sigusr1_handler);
1037         signal(SIGUSR2, sigusr2_handler);
1038         signal(SIGCHLD, sigchld_handler);
1039 #ifdef MAINTAINER_MODE
1040         signal(SIGSEGV, rsync_panic_handler);
1041         signal(SIGFPE, rsync_panic_handler);
1042         signal(SIGABRT, rsync_panic_handler);
1043         signal(SIGBUS, rsync_panic_handler);
1044 #endif /* def MAINTAINER_MODE */
1045
1046         starttime = time(NULL);
1047         am_root = (MY_UID() == 0);
1048
1049         memset(&stats, 0, sizeof(stats));
1050
1051         if (argc < 2) {
1052                 usage(FERROR);
1053                 exit_cleanup(RERR_SYNTAX);
1054         }
1055
1056         /* we set a 0 umask so that correct file permissions can be
1057          * carried across */
1058         orig_umask = (int)umask(0);
1059
1060         if (!parse_arguments(&argc, (const char ***) &argv, 1)) {
1061                 /* FIXME: We ought to call the same error-handling
1062                  * code here, rather than relying on getopt. */
1063                 option_error();
1064                 exit_cleanup(RERR_SYNTAX);
1065         }
1066
1067         signal(SIGINT,SIGNAL_CAST sig_int);
1068         signal(SIGHUP,SIGNAL_CAST sig_int);
1069         signal(SIGTERM,SIGNAL_CAST sig_int);
1070
1071         /* Ignore SIGPIPE; we consistently check error codes and will
1072          * see the EPIPE. */
1073         signal(SIGPIPE, SIG_IGN);
1074
1075         /* Initialize push_dir here because on some old systems getcwd
1076          * (implemented by forking "pwd" and reading its output) doesn't
1077          * work when there are other child processes.  Also, on all systems
1078          * that implement getcwd that way "pwd" can't be found after chroot. */
1079         push_dir(NULL);
1080
1081         init_flist();
1082
1083         if (write_batch || read_batch) {
1084                 if (write_batch)
1085                         write_batch_shell_file(orig_argc, orig_argv, argc);
1086
1087                 if (read_batch && strcmp(batch_name, "-") == 0)
1088                         batch_fd = STDIN_FILENO;
1089                 else {
1090                         batch_fd = do_open(batch_name,
1091                                    write_batch ? O_WRONLY | O_CREAT | O_TRUNC
1092                                    : O_RDONLY, S_IRUSR | S_IWUSR);
1093                 }
1094                 if (batch_fd < 0) {
1095                         rsyserr(FERROR, errno, "Batch file %s open error",
1096                                 batch_name);
1097                         exit_cleanup(RERR_FILEIO);
1098                 }
1099                 if (read_batch)
1100                         read_stream_flags(batch_fd);
1101         }
1102
1103         if (am_daemon && !am_server)
1104                 return daemon_main();
1105
1106         if (argc < 1) {
1107                 usage(FERROR);
1108                 exit_cleanup(RERR_SYNTAX);
1109         }
1110
1111         if (dry_run)
1112                 verbose = MAX(verbose,1);
1113
1114         if (am_server) {
1115                 set_nonblocking(STDIN_FILENO);
1116                 set_nonblocking(STDOUT_FILENO);
1117                 if (am_daemon)
1118                         return start_daemon(STDIN_FILENO, STDOUT_FILENO);
1119                 start_server(STDIN_FILENO, STDOUT_FILENO, argc, argv);
1120         }
1121
1122         ret = start_client(argc, argv);
1123         if (ret == -1)
1124                 exit_cleanup(RERR_STARTCLIENT);
1125         else
1126                 exit_cleanup(ret);
1127
1128         return ret;
1129 }