1 /* $OpenBSD: history.c,v 1.41 2015/09/01 13:12:31 tedu Exp $ */
2 /* $OpenBSD: trap.c,v 1.23 2010/05/19 17:36:08 jasper Exp $ */
3
4 /*-
5 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
6 * 2011, 2012, 2014, 2015, 2016, 2017, 2018, 2019
7 * mirabilos <m@mirbsd.org>
8 *
9 * Provided that these terms and disclaimer and all copyright notices
10 * are retained or reproduced in an accompanying document, permission
11 * is granted to deal in this work without restriction, including un-
12 * limited rights to use, publicly perform, distribute, sell, modify,
13 * merge, give away, or sublicence.
14 *
15 * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
16 * the utmost extent permitted by applicable law, neither express nor
17 * implied; without malicious intent or gross negligence. In no event
18 * may a licensor, author or contributor be held liable for indirect,
19 * direct, other damage, loss, or other issues arising in any way out
20 * of dealing in the work, even if advised of the possibility of such
21 * damage or existence of a defect, except proven that it results out
22 * of said person's immediate fault when using the work as intended.
23 */
24
25 #include "sh.h"
26 #if HAVE_SYS_FILE_H
27 #include <sys/file.h>
28 #endif
29
30 __RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.169 2019/09/16 21:10:33 tg Exp $");
31
32 Trap sigtraps[ksh_NSIG + 1];
33 static struct sigaction Sigact_ign;
34
35 #if HAVE_PERSISTENT_HISTORY
36 static int histload(Source *, unsigned char *, size_t);
37 static int writehistline(int, int, const char *);
38 static void writehistfile(int, const char *);
39 #endif
40
41 static int hist_execute(char *, Area *);
42 static char **hist_get(const char *, bool, bool);
43 static char **hist_get_oldest(void);
44
45 static bool hstarted; /* set after hist_init() called */
46 static Source *hist_source;
47
48 #if HAVE_PERSISTENT_HISTORY
49 /*XXX imake style */
50 #if defined(__linux)
51 #define caddr_cast(x) ((void *)(x))
52 #else
53 #define caddr_cast(x) ((caddr_t)(x))
54 #endif
55
56 /* several OEs do not have these constants */
57 #ifndef MAP_FAILED
58 #define MAP_FAILED caddr_cast(-1)
59 #endif
60
61 /* some OEs need the default mapping type specified */
62 #ifndef MAP_FILE
63 #define MAP_FILE 0
64 #endif
65
66 /* current history file: name, fd, size */
67 static char *hname;
68 static int histfd = -1;
69 static off_t histfsize;
70 #endif
71
72 /* HISTSIZE default: size of saved history, persistent or standard */
73 #ifdef MKSH_SMALL
74 #define MKSH_DEFHISTSIZE 255
75 #else
76 #define MKSH_DEFHISTSIZE 2047
77 #endif
78 /* maximum considered size of persistent history file */
79 #define MKSH_MAXHISTFSIZE ((off_t)1048576 * 96)
80
81 /* hidden option */
82 #define HIST_DISCARD 5
83
84 int
c_fc(const char ** wp)85 c_fc(const char **wp)
86 {
87 struct shf *shf;
88 struct temp *tf;
89 bool gflag = false, lflag = false, nflag = false, rflag = false,
90 sflag = false;
91 int optc;
92 const char *p, *first = NULL, *last = NULL;
93 char **hfirst, **hlast, **hp, *editor = NULL;
94
95 if (!Flag(FTALKING_I)) {
96 bi_errorf("history %ss not available", Tfunction);
97 return (1);
98 }
99
100 while ((optc = ksh_getopt(wp, &builtin_opt,
101 "e:glnrs0,1,2,3,4,5,6,7,8,9,")) != -1)
102 switch (optc) {
103
104 case 'e':
105 p = builtin_opt.optarg;
106 if (ksh_isdash(p))
107 sflag = true;
108 else {
109 size_t len = strlen(p);
110
111 /* almost certainly not overflowing */
112 editor = alloc(len + 4, ATEMP);
113 memcpy(editor, p, len);
114 memcpy(editor + len, Tspdollaru, 4);
115 }
116 break;
117
118 /* non-AT&T ksh */
119 case 'g':
120 gflag = true;
121 break;
122
123 case 'l':
124 lflag = true;
125 break;
126
127 case 'n':
128 nflag = true;
129 break;
130
131 case 'r':
132 rflag = true;
133 break;
134
135 /* POSIX version of -e - */
136 case 's':
137 sflag = true;
138 break;
139
140 /* kludge city - accept -num as -- -num (kind of) */
141 case '0': case '1': case '2': case '3': case '4':
142 case '5': case '6': case '7': case '8': case '9':
143 p = shf_smprintf("-%c%s",
144 optc, builtin_opt.optarg);
145 if (!first)
146 first = p;
147 else if (!last)
148 last = p;
149 else {
150 bi_errorf(Ttoo_many_args);
151 return (1);
152 }
153 break;
154
155 case '?':
156 return (1);
157 }
158 wp += builtin_opt.optind;
159
160 /* Substitute and execute command */
161 if (sflag) {
162 char *pat = NULL, *rep = NULL, *line;
163
164 if (editor || lflag || nflag || rflag) {
165 bi_errorf("can't use -e, -l, -n, -r with -s (-e -)");
166 return (1);
167 }
168
169 /* Check for pattern replacement argument */
170 if (*wp && **wp && (p = cstrchr(*wp + 1, '='))) {
171 strdupx(pat, *wp, ATEMP);
172 rep = pat + (p - *wp);
173 *rep++ = '\0';
174 wp++;
175 }
176 /* Check for search prefix */
177 if (!first && (first = *wp))
178 wp++;
179 if (last || *wp) {
180 bi_errorf(Ttoo_many_args);
181 return (1);
182 }
183
184 hp = first ? hist_get(first, false, false) :
185 hist_get_newest(false);
186 if (!hp)
187 return (1);
188 /* hist_replace */
189 if (!pat)
190 strdupx(line, *hp, ATEMP);
191 else {
192 char *s, *s1;
193 size_t len, pat_len, rep_len;
194 XString xs;
195 char *xp;
196 bool any_subst = false;
197
198 pat_len = strlen(pat);
199 rep_len = strlen(rep);
200 Xinit(xs, xp, 128, ATEMP);
201 for (s = *hp; (s1 = strstr(s, pat)) &&
202 (!any_subst || gflag); s = s1 + pat_len) {
203 any_subst = true;
204 len = s1 - s;
205 XcheckN(xs, xp, len + rep_len);
206 /*; first part */
207 memcpy(xp, s, len);
208 xp += len;
209 /* replacement */
210 memcpy(xp, rep, rep_len);
211 xp += rep_len;
212 }
213 if (!any_subst) {
214 bi_errorf(Tbadsubst);
215 return (1);
216 }
217 len = strlen(s) + 1;
218 XcheckN(xs, xp, len);
219 memcpy(xp, s, len);
220 xp += len;
221 line = Xclose(xs, xp);
222 }
223 return (hist_execute(line, ATEMP));
224 }
225
226 if (editor && (lflag || nflag)) {
227 bi_errorf("can't use -l, -n with -e");
228 return (1);
229 }
230
231 if (!first && (first = *wp))
232 wp++;
233 if (!last && (last = *wp))
234 wp++;
235 if (*wp) {
236 bi_errorf(Ttoo_many_args);
237 return (1);
238 }
239 if (!first) {
240 hfirst = lflag ? hist_get("-16", true, true) :
241 hist_get_newest(false);
242 if (!hfirst)
243 return (1);
244 /* can't fail if hfirst didn't fail */
245 hlast = hist_get_newest(false);
246 } else {
247 /*
248 * POSIX says not an error if first/last out of bounds
249 * when range is specified; AT&T ksh and pdksh allow out
250 * of bounds for -l as well.
251 */
252 hfirst = hist_get(first, tobool(lflag || last), lflag);
253 if (!hfirst)
254 return (1);
255 hlast = last ? hist_get(last, true, lflag) :
256 (lflag ? hist_get_newest(false) : hfirst);
257 if (!hlast)
258 return (1);
259 }
260 if (hfirst > hlast) {
261 char **temp;
262
263 temp = hfirst; hfirst = hlast; hlast = temp;
264 /* POSIX */
265 rflag = !rflag;
266 }
267
268 /* List history */
269 if (lflag) {
270 char *s, *t;
271
272 for (hp = rflag ? hlast : hfirst;
273 hp >= hfirst && hp <= hlast; hp += rflag ? -1 : 1) {
274 if (!nflag)
275 shf_fprintf(shl_stdout, Tf_lu,
276 (unsigned long)hist_source->line -
277 (unsigned long)(histptr - hp));
278 shf_putc('\t', shl_stdout);
279 /* print multi-line commands correctly */
280 s = *hp;
281 while ((t = strchr(s, '\n'))) {
282 *t = '\0';
283 shf_fprintf(shl_stdout, "%s\n\t", s);
284 *t++ = '\n';
285 s = t;
286 }
287 shf_fprintf(shl_stdout, Tf_sN, s);
288 }
289 shf_flush(shl_stdout);
290 return (0);
291 }
292
293 /* Run editor on selected lines, then run resulting commands */
294
295 tf = maketemp(ATEMP, TT_HIST_EDIT, &e->temps);
296 if (!(shf = tf->shf)) {
297 bi_errorf(Tf_temp, Tcreate, tf->tffn, cstrerror(errno));
298 return (1);
299 }
300 for (hp = rflag ? hlast : hfirst;
301 hp >= hfirst && hp <= hlast; hp += rflag ? -1 : 1)
302 shf_fprintf(shf, Tf_sN, *hp);
303 if (shf_close(shf) == -1) {
304 bi_errorf(Tf_temp, Twrite, tf->tffn, cstrerror(errno));
305 return (1);
306 }
307
308 /* Ignore setstr errors here (arbitrary) */
309 setstr(local("_", false), tf->tffn, KSH_RETURN_ERROR);
310
311 if ((optc = command(editor ? editor : TFCEDIT_dollaru, 0)))
312 return (optc);
313
314 {
315 struct stat statb;
316 XString xs;
317 char *xp;
318 ssize_t n;
319
320 if (!(shf = shf_open(tf->tffn, O_RDONLY, 0, 0))) {
321 bi_errorf(Tf_temp, Topen, tf->tffn, cstrerror(errno));
322 return (1);
323 }
324
325 if (stat(tf->tffn, &statb) < 0)
326 n = 128;
327 else if ((off_t)statb.st_size > MKSH_MAXHISTFSIZE) {
328 bi_errorf(Tf_toolarge, Thistory,
329 Tfile, (unsigned long)statb.st_size);
330 goto errout;
331 } else
332 n = (size_t)statb.st_size + 1;
333 Xinit(xs, xp, n, hist_source->areap);
334 while ((n = shf_read(xp, Xnleft(xs, xp), shf)) > 0) {
335 xp += n;
336 if (Xnleft(xs, xp) <= 0)
337 XcheckN(xs, xp, Xlength(xs, xp));
338 }
339 if (n < 0) {
340 bi_errorf(Tf_temp, Tread, tf->tffn,
341 cstrerror(shf_errno(shf)));
342 errout:
343 shf_close(shf);
344 return (1);
345 }
346 shf_close(shf);
347 *xp = '\0';
348 strip_nuls(Xstring(xs, xp), Xlength(xs, xp));
349 return (hist_execute(Xstring(xs, xp), hist_source->areap));
350 }
351 }
352
353 /* save cmd in history, execute cmd (cmd gets afree’d) */
354 static int
hist_execute(char * cmd,Area * areap)355 hist_execute(char *cmd, Area *areap)
356 {
357 static int last_line = -1;
358
359 /* Back up over last histsave */
360 if (histptr >= history && last_line != hist_source->line) {
361 hist_source->line--;
362 afree(*histptr, APERM);
363 histptr--;
364 last_line = hist_source->line;
365 }
366
367 histsave(&hist_source->line, cmd, HIST_STORE, true);
368 /* now *histptr == cmd without all trailing newlines */
369 afree(cmd, areap);
370 cmd = *histptr;
371 /* pdksh says POSIX doesn’t say this is done, testsuite needs it */
372 shellf(Tf_sN, cmd);
373
374 /*-
375 * Commands are executed here instead of pushing them onto the
376 * input 'cause POSIX says the redirection and variable assignments
377 * in
378 * X=y fc -e - 42 2> /dev/null
379 * are to effect the repeated commands environment.
380 */
381 return (command(cmd, 0));
382 }
383
384 /*
385 * get pointer to history given pattern
386 * pattern is a number or string
387 */
388 static char **
hist_get(const char * str,bool approx,bool allow_cur)389 hist_get(const char *str, bool approx, bool allow_cur)
390 {
391 char **hp = NULL;
392 int n;
393
394 if (getn(str, &n)) {
395 hp = histptr + (n < 0 ? n : (n - hist_source->line));
396 if ((size_t)hp < (size_t)history) {
397 if (approx)
398 hp = hist_get_oldest();
399 else {
400 bi_errorf(Tf_sD_s, str, Tnot_in_history);
401 hp = NULL;
402 }
403 } else if ((size_t)hp > (size_t)histptr) {
404 if (approx)
405 hp = hist_get_newest(allow_cur);
406 else {
407 bi_errorf(Tf_sD_s, str, Tnot_in_history);
408 hp = NULL;
409 }
410 } else if (!allow_cur && hp == histptr) {
411 bi_errorf(Tf_sD_s, str, "invalid range");
412 hp = NULL;
413 }
414 } else {
415 bool anchored = *str == '?' ? (++str, false) : true;
416
417 /* the -1 is to avoid the current fc command */
418 if ((n = findhist(histptr - history - 1, 0, str, anchored)) < 0)
419 bi_errorf(Tf_sD_s, str, Tnot_in_history);
420 else
421 hp = &history[n];
422 }
423 return (hp);
424 }
425
426 /* Return a pointer to the newest command in the history */
427 char **
hist_get_newest(bool allow_cur)428 hist_get_newest(bool allow_cur)
429 {
430 if (histptr < history || (!allow_cur && histptr == history)) {
431 bi_errorf("no history (yet)");
432 return (NULL);
433 }
434 return (allow_cur ? histptr : histptr - 1);
435 }
436
437 /* Return a pointer to the oldest command in the history */
438 static char **
hist_get_oldest(void)439 hist_get_oldest(void)
440 {
441 if (histptr <= history) {
442 bi_errorf("no history (yet)");
443 return (NULL);
444 }
445 return (history);
446 }
447
448 #if !defined(MKSH_NO_CMDLINE_EDITING) && !MKSH_S_NOVI
449 /* current position in history[] */
450 static char **current;
451
452 /*
453 * Return the current position.
454 */
455 char **
histpos(void)456 histpos(void)
457 {
458 return (current);
459 }
460
461 int
histnum(int n)462 histnum(int n)
463 {
464 int last = histptr - history;
465
466 if (n < 0 || n >= last) {
467 current = histptr;
468 return (last);
469 } else {
470 current = &history[n];
471 return (n);
472 }
473 }
474 #endif
475
476 /*
477 * This will become unnecessary if hist_get is modified to allow
478 * searching from positions other than the end, and in either
479 * direction.
480 */
481 int
findhist(int start,int fwd,const char * str,bool anchored)482 findhist(int start, int fwd, const char *str, bool anchored)
483 {
484 char **hp;
485 int maxhist = histptr - history;
486 int incr = fwd ? 1 : -1;
487 size_t len = strlen(str);
488
489 if (start < 0 || start >= maxhist)
490 start = maxhist;
491
492 hp = &history[start];
493 for (; hp >= history && hp <= histptr; hp += incr)
494 if ((anchored && strncmp(*hp, str, len) == 0) ||
495 (!anchored && strstr(*hp, str)))
496 return (hp - history);
497
498 return (-1);
499 }
500
501 /*
502 * set history; this means reallocating the dataspace
503 */
504 void
sethistsize(mksh_ari_t n)505 sethistsize(mksh_ari_t n)
506 {
507 if (n > 65535)
508 n = 65535;
509 if (n > 0 && n != histsize) {
510 int cursize = histptr - history;
511
512 /* save most recent history */
513 if (n < cursize) {
514 memmove(history, histptr - n + 1, n * sizeof(char *));
515 cursize = n - 1;
516 }
517
518 history = aresize2(history, n, sizeof(char *), APERM);
519
520 histsize = n;
521 histptr = history + cursize;
522 }
523 }
524
525 #if HAVE_PERSISTENT_HISTORY
526 /*
527 * set history file; this can mean reloading/resetting/starting
528 * history file maintenance
529 */
530 void
sethistfile(const char * name)531 sethistfile(const char *name)
532 {
533 /* if not started then nothing to do */
534 if (hstarted == false)
535 return;
536
537 /* if the name is the same as the name we have */
538 if (hname && name && !strcmp(hname, name))
539 return;
540
541 /*
542 * it's a new name - possibly
543 */
544 if (histfd != -1) {
545 /* yes the file is open */
546 (void)close(histfd);
547 histfd = -1;
548 histfsize = 0;
549 afree(hname, APERM);
550 hname = NULL;
551 /* let's reset the history */
552 histsave(NULL, NULL, HIST_DISCARD, true);
553 histptr = history - 1;
554 hist_source->line = 0;
555 }
556
557 if (name)
558 hist_init(hist_source);
559 }
560 #endif
561
562 /*
563 * initialise the history vector
564 */
565 void
init_histvec(void)566 init_histvec(void)
567 {
568 if (history == (char **)NULL) {
569 histsize = MKSH_DEFHISTSIZE;
570 history = alloc2(histsize, sizeof(char *), APERM);
571 histptr = history - 1;
572 }
573 }
574
575
576 /*
577 * It turns out that there is a lot of ghastly hackery here
578 */
579
580 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
581 /* do not save command in history but possibly sync */
582 bool
histsync(void)583 histsync(void)
584 {
585 bool changed = false;
586
587 /* called by histsave(), may not HIST_DISCARD, caller should flush */
588
589 if (histfd != -1) {
590 int lno = hist_source->line;
591
592 hist_source->line++;
593 writehistfile(0, NULL);
594 hist_source->line--;
595
596 if (lno != hist_source->line)
597 changed = true;
598 }
599
600 return (changed);
601 }
602 #endif
603
604 /*
605 * save command in history
606 */
607 void
histsave(int * lnp,const char * cmd,int svmode,bool ignoredups)608 histsave(int *lnp, const char *cmd, int svmode, bool ignoredups)
609 {
610 static char *enqueued = NULL;
611 char **hp, *c;
612 const char *ccp;
613
614 if (svmode == HIST_DISCARD) {
615 afree(enqueued, APERM);
616 enqueued = NULL;
617 return;
618 }
619
620 if (svmode == HIST_APPEND) {
621 if (!enqueued)
622 svmode = HIST_STORE;
623 } else if (enqueued) {
624 c = enqueued;
625 enqueued = NULL;
626 --*lnp;
627 histsave(lnp, c, HIST_STORE, true);
628 afree(c, APERM);
629 }
630
631 if (svmode == HIST_FLUSH)
632 return;
633
634 ccp = strnul(cmd);
635 while (ccp > cmd && ccp[-1] == '\n')
636 --ccp;
637 strndupx(c, cmd, ccp - cmd, APERM);
638
639 if (svmode != HIST_APPEND) {
640 if (ignoredups &&
641 histptr >= history &&
642 !strcmp(c, *histptr)
643 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
644 && !histsync()
645 #endif
646 ) {
647 afree(c, APERM);
648 return;
649 }
650 ++*lnp;
651 }
652
653 #if HAVE_PERSISTENT_HISTORY
654 if (svmode == HIST_STORE && histfd != -1)
655 writehistfile(*lnp, c);
656 #endif
657
658 if (svmode == HIST_QUEUE || svmode == HIST_APPEND) {
659 size_t nenq, ncmd;
660
661 if (!enqueued) {
662 if (*c)
663 enqueued = c;
664 else
665 afree(c, APERM);
666 return;
667 }
668
669 nenq = strlen(enqueued);
670 ncmd = strlen(c);
671 enqueued = aresize(enqueued, nenq + 1 + ncmd + 1, APERM);
672 enqueued[nenq] = '\n';
673 memcpy(enqueued + nenq + 1, c, ncmd + 1);
674 afree(c, APERM);
675 return;
676 }
677
678 hp = histptr;
679
680 if (++hp >= history + histsize) {
681 /* remove oldest command */
682 afree(*history, APERM);
683 for (hp = history; hp < history + histsize - 1; hp++)
684 hp[0] = hp[1];
685 }
686 *hp = c;
687 histptr = hp;
688 }
689
690 /*
691 * Write history data to a file nominated by HISTFILE;
692 * if HISTFILE is unset then history still happens, but
693 * the data is not written to a file. All copies of ksh
694 * looking at the file will maintain the same history.
695 * This is ksh behaviour.
696 *
697 * This stuff uses mmap()
698 *
699 * This stuff is so totally broken it must eventually be
700 * redesigned, without mmap, better checks, support for
701 * larger files, etc. and handle partially corrupted files
702 */
703
704 /*-
705 * Open a history file
706 * Format is:
707 * Bytes 1, 2:
708 * HMAGIC - just to check that we are dealing with the correct object
709 * Then follows a number of stored commands
710 * Each command is
711 * <command byte><command number(4 octets, big endian)><bytes><NUL>
712 */
713 #define HMAGIC1 0xAB
714 #define HMAGIC2 0xCD
715 #define COMMAND 0xFF
716
717 #if HAVE_PERSISTENT_HISTORY
718 static const unsigned char sprinkle[2] = { HMAGIC1, HMAGIC2 };
719
720 static int
hist_persist_back(int srcfd)721 hist_persist_back(int srcfd)
722 {
723 off_t tot, mis;
724 ssize_t n, w;
725 char *buf, *cp;
726 int rv = 0;
727 #define MKSH_HS_BUFSIZ 4096
728
729 if ((tot = lseek(srcfd, (off_t)0, SEEK_END)) < 0 ||
730 lseek(srcfd, (off_t)0, SEEK_SET) < 0 ||
731 lseek(histfd, (off_t)0, SEEK_SET) < 0)
732 return (1);
733
734 if ((buf = malloc_osfunc(MKSH_HS_BUFSIZ)) == NULL)
735 return (1);
736
737 mis = tot;
738 while (mis > 0) {
739 if ((n = blocking_read(srcfd, (cp = buf),
740 MKSH_HS_BUFSIZ)) == -1) {
741 if (errno == EINTR) {
742 intrcheck();
743 continue;
744 }
745 goto copy_error;
746 }
747 mis -= n;
748 while (n) {
749 if (intrsig)
750 goto has_intrsig;
751 if ((w = write(histfd, cp, n)) != -1) {
752 n -= w;
753 cp += w;
754 continue;
755 }
756 if (errno == EINTR) {
757 has_intrsig:
758 intrcheck();
759 continue;
760 }
761 goto copy_error;
762 }
763 }
764 if (ftruncate(histfd, tot)) {
765 copy_error:
766 rv = 1;
767 }
768 free_osfunc(buf);
769 return (rv);
770 }
771
772 static void
hist_persist_init(void)773 hist_persist_init(void)
774 {
775 unsigned char *base;
776 int lines, fd;
777 enum { hist_init_first, hist_init_retry, hist_use_it } hs;
778
779 if (((hname = str_val(global("HISTFILE"))) == NULL) || !*hname) {
780 hname = NULL;
781 return;
782 }
783 strdupx(hname, hname, APERM);
784 hs = hist_init_first;
785
786 retry:
787 /* we have a file and are interactive */
788 if ((fd = binopen3(hname, O_RDWR | O_CREAT | O_APPEND, 0600)) < 0)
789 return;
790 if ((histfd = savefd(fd)) < 0)
791 return;
792 if (histfd != fd)
793 close(fd);
794
795 mksh_lockfd(histfd);
796
797 histfsize = lseek(histfd, (off_t)0, SEEK_END);
798 if (histfsize > MKSH_MAXHISTFSIZE) {
799 /* we ignore too large files but still append to them */
800 goto hist_init_tail;
801 } else if (histfsize > 2) {
802 /* we have some data, check its validity */
803 base = (void *)mmap(NULL, (size_t)histfsize, PROT_READ,
804 MAP_FILE | MAP_PRIVATE, histfd, (off_t)0);
805 if (base == (unsigned char *)MAP_FAILED)
806 goto hist_init_fail;
807 if (base[0] != HMAGIC1 || base[1] != HMAGIC2) {
808 munmap(caddr_cast(base), (size_t)histfsize);
809 goto hist_init_fail;
810 }
811 /* load _all_ data */
812 lines = histload(hist_source, base + 2, (size_t)histfsize - 2);
813 munmap(caddr_cast(base), (size_t)histfsize);
814 /* check if the file needs to be truncated */
815 if (lines > histsize && histptr >= history) {
816 /* you're fucked up with the current code, trust me */
817 char *nhname, **hp;
818 struct stat sb;
819
820 /* create temporary file */
821 nhname = shf_smprintf("%s.%d", hname, (int)procpid);
822 if ((fd = binopen3(nhname, O_RDWR | O_CREAT | O_TRUNC |
823 O_EXCL, 0600)) < 0) {
824 /* just don't truncate then, meh. */
825 hs = hist_use_it;
826 goto hist_trunc_dont;
827 }
828 if (fstat(histfd, &sb) >= 0 &&
829 chown(nhname, sb.st_uid, sb.st_gid)) {
830 /* abort the truncation then, meh. */
831 goto hist_trunc_abort;
832 }
833 /* we definitively want some magic in that file */
834 if (write(fd, sprinkle, 2) != 2)
835 goto hist_trunc_abort;
836 /* and of course the entries */
837 hp = history;
838 while (hp < histptr) {
839 if (!writehistline(fd,
840 hist_source->line - (histptr - hp), *hp))
841 goto hist_trunc_abort;
842 ++hp;
843 }
844 /* now transfer back */
845 if (!hist_persist_back(fd)) {
846 /* success! */
847 hs = hist_use_it;
848 }
849 hist_trunc_abort:
850 /* remove temporary file */
851 close(fd);
852 fd = -1;
853 unlink(nhname);
854 /* use whatever is in the file now */
855 hist_trunc_dont:
856 afree(nhname, ATEMP);
857 if (hs == hist_use_it)
858 goto hist_trunc_done;
859 goto hist_init_fail;
860 }
861 } else if (histfsize != 0) {
862 /* negative or too small... */
863 hist_init_fail:
864 /* ... or mmap failed or illegal */
865 hist_finish();
866 /* nuke the bogus file then retry, at most once */
867 if (!unlink(hname) && hs != hist_init_retry) {
868 hs = hist_init_retry;
869 goto retry;
870 }
871 if (hs != hist_init_retry)
872 bi_errorf(Tf_cant_ss_s,
873 "unlink HISTFILE", hname, cstrerror(errno));
874 histfsize = 0;
875 return;
876 } else {
877 /* size 0, add magic to the history file */
878 if (write(histfd, sprinkle, 2) != 2) {
879 hist_finish();
880 return;
881 }
882 }
883 hist_trunc_done:
884 if ((histfsize = lseek(histfd, (off_t)0, SEEK_END)) < 0)
885 goto hist_init_fail;
886 hist_init_tail:
887 mksh_unlkfd(histfd);
888 }
889 #endif
890
891 void
hist_init(Source * s)892 hist_init(Source *s)
893 {
894 histsave(NULL, NULL, HIST_DISCARD, true);
895
896 if (Flag(FTALKING) == 0)
897 return;
898
899 hstarted = true;
900 hist_source = s;
901
902 #if HAVE_PERSISTENT_HISTORY
903 hist_persist_init();
904 #endif
905 }
906
907 #if HAVE_PERSISTENT_HISTORY
908 /*
909 * load the history structure from the stored data
910 */
911 static int
histload(Source * s,unsigned char * base,size_t bytes)912 histload(Source *s, unsigned char *base, size_t bytes)
913 {
914 int lno = 0, lines = 0;
915 unsigned char *cp;
916
917 histload_loop:
918 /* !bytes check as some systems (older FreeBSDs) have buggy memchr */
919 if (!bytes || (cp = memchr(base, COMMAND, bytes)) == NULL)
920 return (lines);
921 /* advance base pointer past COMMAND byte */
922 bytes -= ++cp - base;
923 base = cp;
924 /* if there is no full string left, don't bother with the rest */
925 if (bytes < 5 || (cp = memchr(base + 4, '\0', bytes - 4)) == NULL)
926 return (lines);
927 /* load the stored line number */
928 lno = ((base[0] & 0xFF) << 24) | ((base[1] & 0xFF) << 16) |
929 ((base[2] & 0xFF) << 8) | (base[3] & 0xFF);
930 /* store away the found line (@base[4]) */
931 ++lines;
932 if (histptr >= history && lno - 1 != s->line) {
933 /* a replacement? */
934 char **hp;
935
936 if (lno >= s->line - (histptr - history) && lno <= s->line) {
937 hp = &histptr[lno - s->line];
938 afree(*hp, APERM);
939 strdupx(*hp, (char *)(base + 4), APERM);
940 }
941 } else {
942 s->line = lno--;
943 histsave(&lno, (char *)(base + 4), HIST_NOTE, false);
944 }
945 /* advance base pointer past NUL */
946 bytes -= ++cp - base;
947 base = cp;
948 /* repeat until no more */
949 goto histload_loop;
950 }
951
952 /*
953 * write a command to the end of the history file
954 *
955 * This *MAY* seem easy but it's also necessary to check
956 * that the history file has not changed in size.
957 * If it has - then some other shell has written to it and
958 * we should (re)read those commands to update our history
959 */
960 static void
writehistfile(int lno,const char * cmd)961 writehistfile(int lno, const char *cmd)
962 {
963 off_t sizenow;
964 size_t bytes;
965 unsigned char *base, *news;
966
967 mksh_lockfd(histfd);
968 if ((sizenow = lseek(histfd, (off_t)0, SEEK_END)) < 0)
969 goto bad;
970 else if (sizenow < histfsize) {
971 /* the file has shrunk; trust it just appending the new data */
972 /* well, for now, anyway… since mksh strdups all into memory */
973 /* we can use a nicer approach some time later… */
974 ;
975 } else if (
976 /* ignore changes when the file is too large */
977 sizenow <= MKSH_MAXHISTFSIZE
978 &&
979 /* the size has changed, we need to do read updates */
980 sizenow > histfsize
981 ) {
982 /* both sizenow and histfsize are <= MKSH_MAXHISTFSIZE */
983 bytes = (size_t)(sizenow - histfsize);
984 base = (void *)mmap(NULL, (size_t)sizenow, PROT_READ,
985 MAP_FILE | MAP_PRIVATE, histfd, (off_t)0);
986 if (base == (unsigned char *)MAP_FAILED)
987 goto bad;
988 news = base + (size_t)histfsize;
989 if (*news == COMMAND) {
990 hist_source->line--;
991 histload(hist_source, news, bytes);
992 hist_source->line++;
993 lno = hist_source->line;
994 } else
995 bytes = 0;
996 munmap(caddr_cast(base), (size_t)sizenow);
997 if (!bytes)
998 goto bad;
999 }
1000 if (cmd && !writehistline(histfd, lno, cmd)) {
1001 bad:
1002 hist_finish();
1003 return;
1004 }
1005 if ((histfsize = lseek(histfd, (off_t)0, SEEK_END)) < 0)
1006 goto bad;
1007 mksh_unlkfd(histfd);
1008 }
1009
1010 static int
writehistline(int fd,int lno,const char * cmd)1011 writehistline(int fd, int lno, const char *cmd)
1012 {
1013 ssize_t n;
1014 unsigned char hdr[5];
1015
1016 hdr[0] = COMMAND;
1017 hdr[1] = (lno >> 24) & 0xFF;
1018 hdr[2] = (lno >> 16) & 0xFF;
1019 hdr[3] = (lno >> 8) & 0xFF;
1020 hdr[4] = lno & 0xFF;
1021 n = strlen(cmd) + 1;
1022 return (write(fd, hdr, 5) == 5 && write(fd, cmd, n) == n);
1023 }
1024
1025 void
hist_finish(void)1026 hist_finish(void)
1027 {
1028 if (histfd >= 0) {
1029 mksh_unlkfd(histfd);
1030 (void)close(histfd);
1031 }
1032 histfd = -1;
1033 }
1034 #endif
1035
1036
1037 #if !HAVE_SYS_SIGNAME
1038 static const struct mksh_sigpair {
1039 const char * const name;
1040 int nr;
1041 } mksh_sigpairs[] = {
1042 #include "signames.inc"
1043 { NULL, 0 }
1044 };
1045 #endif
1046
1047 #if HAVE_SYS_SIGLIST
1048 #if !HAVE_SYS_SIGLIST_DECL
1049 extern const char * const sys_siglist[];
1050 #endif
1051 #endif
1052
1053 void
inittraps(void)1054 inittraps(void)
1055 {
1056 int i;
1057 const char *cs;
1058 #if !HAVE_SYS_SIGNAME
1059 const struct mksh_sigpair *pair;
1060 #endif
1061
1062 trap_exstat = -1;
1063
1064 /* populate sigtraps based on sys_signame and sys_siglist */
1065 for (i = 1; i < ksh_NSIG; i++) {
1066 sigtraps[i].signal = i;
1067 #if HAVE_SYS_SIGNAME
1068 cs = sys_signame[i];
1069 #else
1070 pair = mksh_sigpairs;
1071 while ((pair->nr != i) && (pair->name != NULL))
1072 ++pair;
1073 cs = pair->name;
1074 #endif
1075 if ((cs == NULL) ||
1076 (cs[0] == '\0'))
1077 sigtraps[i].name = null;
1078 else {
1079 char *s;
1080
1081 /* this is not optimal, what about SIGSIG1? */
1082 if (ksh_eq(cs[0], 'S', 's') &&
1083 ksh_eq(cs[1], 'I', 'i') &&
1084 ksh_eq(cs[2], 'G', 'g') &&
1085 cs[3] != '\0') {
1086 /* skip leading "SIG" */
1087 cs += 3;
1088 }
1089 strdupx(s, cs, APERM);
1090 sigtraps[i].name = s;
1091 while ((*s = ksh_toupper(*s)))
1092 ++s;
1093 /* check for reserved names */
1094 if (!strcmp(sigtraps[i].name, "EXIT") ||
1095 !strcmp(sigtraps[i].name, "ERR")) {
1096 #ifndef MKSH_SMALL
1097 internal_warningf(Tinvname, sigtraps[i].name,
1098 "signal");
1099 #endif
1100 sigtraps[i].name = null;
1101 }
1102 }
1103 if (sigtraps[i].name == null)
1104 sigtraps[i].name = shf_smprintf(Tf_d, i);
1105 #if HAVE_SYS_SIGLIST
1106 sigtraps[i].mess = sys_siglist[i];
1107 #elif HAVE_STRSIGNAL
1108 sigtraps[i].mess = strsignal(i);
1109 #else
1110 sigtraps[i].mess = NULL;
1111 #endif
1112 if ((sigtraps[i].mess == NULL) ||
1113 (sigtraps[i].mess[0] == '\0'))
1114 sigtraps[i].mess = shf_smprintf(Tf_sd,
1115 "Signal", i);
1116 }
1117 sigtraps[ksh_SIGEXIT].signal = ksh_SIGEXIT;
1118 sigtraps[ksh_SIGEXIT].name = "EXIT";
1119 sigtraps[ksh_SIGEXIT].mess = "Exit trap";
1120 sigtraps[ksh_SIGERR].signal = ksh_SIGERR;
1121 sigtraps[ksh_SIGERR].name = "ERR";
1122 sigtraps[ksh_SIGERR].mess = "Error handler";
1123
1124 (void)sigemptyset(&Sigact_ign.sa_mask);
1125 Sigact_ign.sa_flags = 0; /* interruptible */
1126 Sigact_ign.sa_handler = SIG_IGN;
1127
1128 sigtraps[SIGINT].flags |= TF_DFL_INTR | TF_TTY_INTR;
1129 sigtraps[SIGQUIT].flags |= TF_DFL_INTR | TF_TTY_INTR;
1130 /* SIGTERM is not fatal for interactive */
1131 sigtraps[SIGTERM].flags |= TF_DFL_INTR;
1132 sigtraps[SIGHUP].flags |= TF_FATAL;
1133 sigtraps[SIGCHLD].flags |= TF_SHELL_USES;
1134
1135 /* these are always caught so we can clean up any temporary files. */
1136 setsig(&sigtraps[SIGINT], trapsig, SS_RESTORE_ORIG);
1137 setsig(&sigtraps[SIGQUIT], trapsig, SS_RESTORE_ORIG);
1138 setsig(&sigtraps[SIGTERM], trapsig, SS_RESTORE_ORIG);
1139 setsig(&sigtraps[SIGHUP], trapsig, SS_RESTORE_ORIG);
1140 }
1141
1142 static void alarm_catcher(int sig);
1143
1144 void
alarm_init(void)1145 alarm_init(void)
1146 {
1147 sigtraps[SIGALRM].flags |= TF_SHELL_USES;
1148 setsig(&sigtraps[SIGALRM], alarm_catcher,
1149 SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
1150 }
1151
1152 /* ARGSUSED */
1153 static void
alarm_catcher(int sig MKSH_A_UNUSED)1154 alarm_catcher(int sig MKSH_A_UNUSED)
1155 {
1156 /* this runs inside interrupt context, with errno saved */
1157
1158 if (ksh_tmout_state == TMOUT_READING) {
1159 int left = alarm(0);
1160
1161 if (left == 0) {
1162 ksh_tmout_state = TMOUT_LEAVING;
1163 intrsig = 1;
1164 } else
1165 alarm(left);
1166 }
1167 }
1168
1169 Trap *
gettrap(const char * cs,bool igncase,bool allsigs)1170 gettrap(const char *cs, bool igncase, bool allsigs)
1171 {
1172 int i;
1173 Trap *p;
1174 char *as;
1175
1176 /* signal number (1..ksh_NSIG) or 0? */
1177
1178 if (ctype(*cs, C_DIGIT))
1179 return ((getn(cs, &i) && 0 <= i && i < ksh_NSIG) ?
1180 (&sigtraps[i]) : NULL);
1181
1182 /* do a lookup by name then */
1183
1184 /* this breaks SIGSIG1, but we do that above anyway */
1185 if (ksh_eq(cs[0], 'S', 's') &&
1186 ksh_eq(cs[1], 'I', 'i') &&
1187 ksh_eq(cs[2], 'G', 'g') &&
1188 cs[3] != '\0') {
1189 /* skip leading "SIG" */
1190 cs += 3;
1191 }
1192 if (igncase) {
1193 char *s;
1194
1195 strdupx(as, cs, ATEMP);
1196 cs = s = as;
1197 while ((*s = ksh_toupper(*s)))
1198 ++s;
1199 } else
1200 as = NULL;
1201
1202 /* this is idiotic, we really want a hashtable here */
1203
1204 p = sigtraps;
1205 i = ksh_NSIG + 1;
1206 do {
1207 if (!strcmp(p->name, cs))
1208 goto found;
1209 ++p;
1210 } while (--i);
1211 goto notfound;
1212
1213 found:
1214 if (!allsigs) {
1215 if (p->signal == ksh_SIGEXIT || p->signal == ksh_SIGERR) {
1216 notfound:
1217 p = NULL;
1218 }
1219 }
1220 afree(as, ATEMP);
1221 return (p);
1222 }
1223
1224 /*
1225 * trap signal handler
1226 */
1227 void
trapsig(int i)1228 trapsig(int i)
1229 {
1230 Trap *p = &sigtraps[i];
1231 int eno = errno;
1232
1233 trap = p->set = 1;
1234 if (p->flags & TF_DFL_INTR)
1235 intrsig = 1;
1236 if ((p->flags & TF_FATAL) && !p->trap) {
1237 fatal_trap = 1;
1238 intrsig = 1;
1239 }
1240 if (p->shtrap)
1241 (*p->shtrap)(i);
1242 errno = eno;
1243 }
1244
1245 /*
1246 * called when we want to allow the user to ^C out of something - won't
1247 * work if user has trapped SIGINT.
1248 */
1249 void
intrcheck(void)1250 intrcheck(void)
1251 {
1252 if (intrsig)
1253 runtraps(TF_DFL_INTR|TF_FATAL);
1254 }
1255
1256 /*
1257 * called after EINTR to check if a signal with normally causes process
1258 * termination has been received.
1259 */
1260 int
fatal_trap_check(void)1261 fatal_trap_check(void)
1262 {
1263 Trap *p = sigtraps;
1264 int i = ksh_NSIG + 1;
1265
1266 /* todo: should check if signal is fatal, not the TF_DFL_INTR flag */
1267 do {
1268 if (p->set && (p->flags & (TF_DFL_INTR|TF_FATAL)))
1269 /* return value is used as an exit code */
1270 return (ksh_sigmask(p->signal));
1271 ++p;
1272 } while (--i);
1273 return (0);
1274 }
1275
1276 /*
1277 * Returns the signal number of any pending traps: ie, a signal which has
1278 * occurred for which a trap has been set or for which the TF_DFL_INTR flag
1279 * is set.
1280 */
1281 int
trap_pending(void)1282 trap_pending(void)
1283 {
1284 Trap *p = sigtraps;
1285 int i = ksh_NSIG + 1;
1286
1287 do {
1288 if (p->set && ((p->trap && p->trap[0]) ||
1289 ((p->flags & (TF_DFL_INTR|TF_FATAL)) && !p->trap)))
1290 return (p->signal);
1291 ++p;
1292 } while (--i);
1293 return (0);
1294 }
1295
1296 /*
1297 * run any pending traps. If intr is set, only run traps that
1298 * can interrupt commands.
1299 */
1300 void
runtraps(int flag)1301 runtraps(int flag)
1302 {
1303 Trap *p = sigtraps;
1304 int i = ksh_NSIG + 1;
1305
1306 if (ksh_tmout_state == TMOUT_LEAVING) {
1307 ksh_tmout_state = TMOUT_EXECUTING;
1308 warningf(false, "timed out waiting for input");
1309 unwind(LEXIT);
1310 } else
1311 /*
1312 * XXX: this means the alarm will have no effect if a trap
1313 * is caught after the alarm() was started...not good.
1314 */
1315 ksh_tmout_state = TMOUT_EXECUTING;
1316 if (!flag)
1317 trap = 0;
1318 if (flag & TF_DFL_INTR)
1319 intrsig = 0;
1320 if (flag & TF_FATAL)
1321 fatal_trap = 0;
1322 ++trap_nested;
1323 do {
1324 if (p->set && (!flag ||
1325 ((p->flags & flag) && p->trap == NULL)))
1326 runtrap(p, false);
1327 ++p;
1328 } while (--i);
1329 if (!--trap_nested)
1330 runtrap(NULL, true);
1331 }
1332
1333 void
runtrap(Trap * p,bool is_last)1334 runtrap(Trap *p, bool is_last)
1335 {
1336 int old_changed = 0, i;
1337 char *trapstr;
1338
1339 if (p == NULL)
1340 /* just clean up, see runtraps() above */
1341 goto donetrap;
1342 i = p->signal;
1343 trapstr = p->trap;
1344 p->set = 0;
1345 if (trapstr == NULL) {
1346 /* SIG_DFL */
1347 if (p->flags & (TF_FATAL | TF_DFL_INTR)) {
1348 exstat = (int)(128U + (unsigned)i);
1349 if ((unsigned)exstat > 255U)
1350 exstat = 255;
1351 }
1352 /* e.g. SIGHUP */
1353 if (p->flags & TF_FATAL)
1354 unwind(LLEAVE);
1355 /* e.g. SIGINT, SIGQUIT, SIGTERM, etc. */
1356 if (p->flags & TF_DFL_INTR)
1357 unwind(LINTR);
1358 goto donetrap;
1359 }
1360 if (trapstr[0] == '\0')
1361 /* SIG_IGN */
1362 goto donetrap;
1363 if (i == ksh_SIGEXIT || i == ksh_SIGERR) {
1364 /* avoid recursion on these */
1365 old_changed = p->flags & TF_CHANGED;
1366 p->flags &= ~TF_CHANGED;
1367 p->trap = NULL;
1368 }
1369 if (trap_exstat == -1)
1370 trap_exstat = exstat & 0xFF;
1371 /*
1372 * Note: trapstr is fully parsed before anything is executed, thus
1373 * no problem with afree(p->trap) in settrap() while still in use.
1374 */
1375 command(trapstr, current_lineno);
1376 if (i == ksh_SIGEXIT || i == ksh_SIGERR) {
1377 if (p->flags & TF_CHANGED)
1378 /* don't clear TF_CHANGED */
1379 afree(trapstr, APERM);
1380 else
1381 p->trap = trapstr;
1382 p->flags |= old_changed;
1383 }
1384
1385 donetrap:
1386 /* we're the last trap of a sequence executed */
1387 if (is_last && trap_exstat != -1) {
1388 exstat = trap_exstat;
1389 trap_exstat = -1;
1390 }
1391 }
1392
1393 /* clear pending traps and reset user's trap handlers; used after fork(2) */
1394 void
cleartraps(void)1395 cleartraps(void)
1396 {
1397 Trap *p = sigtraps;
1398 int i = ksh_NSIG + 1;
1399
1400 trap = 0;
1401 intrsig = 0;
1402 fatal_trap = 0;
1403
1404 do {
1405 p->set = 0;
1406 if ((p->flags & TF_USER_SET) && (p->trap && p->trap[0]))
1407 settrap(p, NULL);
1408 ++p;
1409 } while (--i);
1410 }
1411
1412 /* restore signals just before an exec(2) */
1413 void
restoresigs(void)1414 restoresigs(void)
1415 {
1416 Trap *p = sigtraps;
1417 int i = ksh_NSIG + 1;
1418
1419 do {
1420 if (p->flags & (TF_EXEC_IGN|TF_EXEC_DFL))
1421 setsig(p, (p->flags & TF_EXEC_IGN) ? SIG_IGN : SIG_DFL,
1422 SS_RESTORE_CURR|SS_FORCE);
1423 ++p;
1424 } while (--i);
1425 }
1426
1427 void
settrap(Trap * p,const char * s)1428 settrap(Trap *p, const char *s)
1429 {
1430 sig_t f;
1431
1432 afree(p->trap, APERM);
1433 /* handles s == NULL */
1434 strdupx(p->trap, s, APERM);
1435 p->flags |= TF_CHANGED;
1436 f = !s ? SIG_DFL : s[0] ? trapsig : SIG_IGN;
1437
1438 p->flags |= TF_USER_SET;
1439 if ((p->flags & (TF_DFL_INTR|TF_FATAL)) && f == SIG_DFL)
1440 f = trapsig;
1441 else if (p->flags & TF_SHELL_USES) {
1442 if (!(p->flags & TF_ORIG_IGN) || Flag(FTALKING)) {
1443 /* do what user wants at exec time */
1444 p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
1445 if (f == SIG_IGN)
1446 p->flags |= TF_EXEC_IGN;
1447 else
1448 p->flags |= TF_EXEC_DFL;
1449 }
1450
1451 /*
1452 * assumes handler already set to what shell wants it
1453 * (normally trapsig, but could be j_sigchld() or SIG_IGN)
1454 */
1455 return;
1456 }
1457
1458 /* todo: should we let user know signal is ignored? how? */
1459 setsig(p, f, SS_RESTORE_CURR|SS_USER);
1460 }
1461
1462 /*
1463 * called by c_print() when writing to a co-process to ensure
1464 * SIGPIPE won't kill shell (unless user catches it and exits)
1465 */
1466 bool
block_pipe(void)1467 block_pipe(void)
1468 {
1469 bool restore_dfl = false;
1470 Trap *p = &sigtraps[SIGPIPE];
1471
1472 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
1473 setsig(p, SIG_IGN, SS_RESTORE_CURR);
1474 if (p->flags & TF_ORIG_DFL)
1475 restore_dfl = true;
1476 } else if (p->cursig == SIG_DFL) {
1477 setsig(p, SIG_IGN, SS_RESTORE_CURR);
1478 /* restore to SIG_DFL */
1479 restore_dfl = true;
1480 }
1481 return (restore_dfl);
1482 }
1483
1484 /* called by c_print() to undo whatever block_pipe() did */
1485 void
restore_pipe(void)1486 restore_pipe(void)
1487 {
1488 setsig(&sigtraps[SIGPIPE], SIG_DFL, SS_RESTORE_CURR);
1489 }
1490
1491 /*
1492 * Set action for a signal. Action may not be set if original
1493 * action was SIG_IGN, depending on the value of flags and FTALKING.
1494 */
1495 int
setsig(Trap * p,sig_t f,int flags)1496 setsig(Trap *p, sig_t f, int flags)
1497 {
1498 struct sigaction sigact;
1499
1500 if (p->signal == ksh_SIGEXIT || p->signal == ksh_SIGERR)
1501 return (1);
1502
1503 memset(&sigact, 0, sizeof(sigact));
1504
1505 /*
1506 * First time setting this signal? If so, get and note the current
1507 * setting.
1508 */
1509 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
1510 sigaction(p->signal, &Sigact_ign, &sigact);
1511 p->flags |= sigact.sa_handler == SIG_IGN ?
1512 TF_ORIG_IGN : TF_ORIG_DFL;
1513 p->cursig = SIG_IGN;
1514 }
1515
1516 /*-
1517 * Generally, an ignored signal stays ignored, except if
1518 * - the user of an interactive shell wants to change it
1519 * - the shell wants for force a change
1520 */
1521 if ((p->flags & TF_ORIG_IGN) && !(flags & SS_FORCE) &&
1522 (!(flags & SS_USER) || !Flag(FTALKING)))
1523 return (0);
1524
1525 setexecsig(p, flags & SS_RESTORE_MASK);
1526
1527 /*
1528 * This is here 'cause there should be a way of clearing
1529 * shtraps, but don't know if this is a sane way of doing
1530 * it. At the moment, all users of shtrap are lifetime
1531 * users (SIGALRM, SIGCHLD, SIGWINCH).
1532 */
1533 if (!(flags & SS_USER))
1534 p->shtrap = (sig_t)NULL;
1535 if (flags & SS_SHTRAP) {
1536 p->shtrap = f;
1537 f = trapsig;
1538 }
1539
1540 if (p->cursig != f) {
1541 p->cursig = f;
1542 (void)sigemptyset(&sigact.sa_mask);
1543 /* interruptible */
1544 sigact.sa_flags = 0;
1545 sigact.sa_handler = f;
1546 sigaction(p->signal, &sigact, NULL);
1547 }
1548
1549 return (1);
1550 }
1551
1552 /* control what signal is set to before an exec() */
1553 void
setexecsig(Trap * p,int restore)1554 setexecsig(Trap *p, int restore)
1555 {
1556 /* XXX debugging */
1557 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL)))
1558 internal_errorf("setexecsig: unset signal %d(%s)",
1559 p->signal, p->name);
1560
1561 /* restore original value for exec'd kids */
1562 p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
1563 switch (restore & SS_RESTORE_MASK) {
1564 case SS_RESTORE_CURR:
1565 /* leave things as they currently are */
1566 break;
1567 case SS_RESTORE_ORIG:
1568 p->flags |= p->flags & TF_ORIG_IGN ? TF_EXEC_IGN : TF_EXEC_DFL;
1569 break;
1570 case SS_RESTORE_DFL:
1571 p->flags |= TF_EXEC_DFL;
1572 break;
1573 case SS_RESTORE_IGN:
1574 p->flags |= TF_EXEC_IGN;
1575 break;
1576 }
1577 }
1578
1579 #if HAVE_PERSISTENT_HISTORY || defined(DF)
1580 /*
1581 * File descriptor locking and unlocking functions.
1582 * Could use some error handling, but hey, this is only
1583 * advisory locking anyway, will often not work over NFS,
1584 * and you are SOL if this fails...
1585 */
1586
1587 void
mksh_lockfd(int fd)1588 mksh_lockfd(int fd)
1589 {
1590 #if defined(__OpenBSD__)
1591 /* flock is not interrupted by signals */
1592 (void)flock(fd, LOCK_EX);
1593 #elif HAVE_FLOCK
1594 int rv;
1595
1596 /* e.g. on Linux */
1597 do {
1598 rv = flock(fd, LOCK_EX);
1599 } while (rv == 1 && errno == EINTR);
1600 #elif HAVE_LOCK_FCNTL
1601 int rv;
1602 struct flock lks;
1603
1604 memset(&lks, 0, sizeof(lks));
1605 lks.l_type = F_WRLCK;
1606 do {
1607 rv = fcntl(fd, F_SETLKW, &lks);
1608 } while (rv == 1 && errno == EINTR);
1609 #endif
1610 }
1611
1612 /* designed to not define mksh_unlkfd if none triggered */
1613 #if HAVE_FLOCK
1614 void
mksh_unlkfd(int fd)1615 mksh_unlkfd(int fd)
1616 {
1617 (void)flock(fd, LOCK_UN);
1618 }
1619 #elif HAVE_LOCK_FCNTL
1620 void
mksh_unlkfd(int fd)1621 mksh_unlkfd(int fd)
1622 {
1623 struct flock lks;
1624
1625 memset(&lks, 0, sizeof(lks));
1626 lks.l_type = F_UNLCK;
1627 (void)fcntl(fd, F_SETLKW, &lks);
1628 }
1629 #endif
1630 #endif
1631