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
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 1.167 2018/04/28 17:16:54 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 > 0 && n != histsize) {
508 int cursize = histptr - history;
509
510 /* save most recent history */
511 if (n < cursize) {
512 memmove(history, histptr - n + 1, n * sizeof(char *));
513 cursize = n - 1;
514 }
515
516 history = aresize2(history, n, sizeof(char *), APERM);
517
518 histsize = n;
519 histptr = history + cursize;
520 }
521 }
522
523 #if HAVE_PERSISTENT_HISTORY
524 /*
525 * set history file; this can mean reloading/resetting/starting
526 * history file maintenance
527 */
528 void
sethistfile(const char * name)529 sethistfile(const char *name)
530 {
531 /* if not started then nothing to do */
532 if (hstarted == false)
533 return;
534
535 /* if the name is the same as the name we have */
536 if (hname && name && !strcmp(hname, name))
537 return;
538
539 /*
540 * it's a new name - possibly
541 */
542 if (histfd != -1) {
543 /* yes the file is open */
544 (void)close(histfd);
545 histfd = -1;
546 histfsize = 0;
547 afree(hname, APERM);
548 hname = NULL;
549 /* let's reset the history */
550 histsave(NULL, NULL, HIST_DISCARD, true);
551 histptr = history - 1;
552 hist_source->line = 0;
553 }
554
555 if (name)
556 hist_init(hist_source);
557 }
558 #endif
559
560 /*
561 * initialise the history vector
562 */
563 void
init_histvec(void)564 init_histvec(void)
565 {
566 if (history == (char **)NULL) {
567 histsize = MKSH_DEFHISTSIZE;
568 history = alloc2(histsize, sizeof(char *), APERM);
569 histptr = history - 1;
570 }
571 }
572
573
574 /*
575 * It turns out that there is a lot of ghastly hackery here
576 */
577
578 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
579 /* do not save command in history but possibly sync */
580 bool
histsync(void)581 histsync(void)
582 {
583 bool changed = false;
584
585 /* called by histsave(), may not HIST_DISCARD, caller should flush */
586
587 if (histfd != -1) {
588 int lno = hist_source->line;
589
590 hist_source->line++;
591 writehistfile(0, NULL);
592 hist_source->line--;
593
594 if (lno != hist_source->line)
595 changed = true;
596 }
597
598 return (changed);
599 }
600 #endif
601
602 /*
603 * save command in history
604 */
605 void
histsave(int * lnp,const char * cmd,int svmode,bool ignoredups)606 histsave(int *lnp, const char *cmd, int svmode, bool ignoredups)
607 {
608 static char *enqueued = NULL;
609 char **hp, *c;
610 const char *ccp;
611
612 if (svmode == HIST_DISCARD) {
613 afree(enqueued, APERM);
614 enqueued = NULL;
615 return;
616 }
617
618 if (svmode == HIST_APPEND) {
619 if (!enqueued)
620 svmode = HIST_STORE;
621 } else if (enqueued) {
622 c = enqueued;
623 enqueued = NULL;
624 --*lnp;
625 histsave(lnp, c, HIST_STORE, true);
626 afree(c, APERM);
627 }
628
629 if (svmode == HIST_FLUSH)
630 return;
631
632 ccp = strnul(cmd);
633 while (ccp > cmd && ccp[-1] == '\n')
634 --ccp;
635 strndupx(c, cmd, ccp - cmd, APERM);
636
637 if (svmode != HIST_APPEND) {
638 if (ignoredups &&
639 histptr >= history &&
640 !strcmp(c, *histptr)
641 #if !defined(MKSH_SMALL) && HAVE_PERSISTENT_HISTORY
642 && !histsync()
643 #endif
644 ) {
645 afree(c, APERM);
646 return;
647 }
648 ++*lnp;
649 }
650
651 #if HAVE_PERSISTENT_HISTORY
652 if (svmode == HIST_STORE && histfd != -1)
653 writehistfile(*lnp, c);
654 #endif
655
656 if (svmode == HIST_QUEUE || svmode == HIST_APPEND) {
657 size_t nenq, ncmd;
658
659 if (!enqueued) {
660 if (*c)
661 enqueued = c;
662 else
663 afree(c, APERM);
664 return;
665 }
666
667 nenq = strlen(enqueued);
668 ncmd = strlen(c);
669 enqueued = aresize(enqueued, nenq + 1 + ncmd + 1, APERM);
670 enqueued[nenq] = '\n';
671 memcpy(enqueued + nenq + 1, c, ncmd + 1);
672 afree(c, APERM);
673 return;
674 }
675
676 hp = histptr;
677
678 if (++hp >= history + histsize) {
679 /* remove oldest command */
680 afree(*history, APERM);
681 for (hp = history; hp < history + histsize - 1; hp++)
682 hp[0] = hp[1];
683 }
684 *hp = c;
685 histptr = hp;
686 }
687
688 /*
689 * Write history data to a file nominated by HISTFILE;
690 * if HISTFILE is unset then history still happens, but
691 * the data is not written to a file. All copies of ksh
692 * looking at the file will maintain the same history.
693 * This is ksh behaviour.
694 *
695 * This stuff uses mmap()
696 *
697 * This stuff is so totally broken it must eventually be
698 * redesigned, without mmap, better checks, support for
699 * larger files, etc. and handle partially corrupted files
700 */
701
702 /*-
703 * Open a history file
704 * Format is:
705 * Bytes 1, 2:
706 * HMAGIC - just to check that we are dealing with the correct object
707 * Then follows a number of stored commands
708 * Each command is
709 * <command byte><command number(4 octets, big endian)><bytes><NUL>
710 */
711 #define HMAGIC1 0xAB
712 #define HMAGIC2 0xCD
713 #define COMMAND 0xFF
714
715 #if HAVE_PERSISTENT_HISTORY
716 static const unsigned char sprinkle[2] = { HMAGIC1, HMAGIC2 };
717
718 static int
hist_persist_back(int srcfd)719 hist_persist_back(int srcfd)
720 {
721 off_t tot, mis;
722 ssize_t n, w;
723 char *buf, *cp;
724 int rv = 0;
725 #define MKSH_HS_BUFSIZ 4096
726
727 if ((tot = lseek(srcfd, (off_t)0, SEEK_END)) < 0 ||
728 lseek(srcfd, (off_t)0, SEEK_SET) < 0 ||
729 lseek(histfd, (off_t)0, SEEK_SET) < 0)
730 return (1);
731
732 if ((buf = malloc_osfunc(MKSH_HS_BUFSIZ)) == NULL)
733 return (1);
734
735 mis = tot;
736 while (mis > 0) {
737 if ((n = blocking_read(srcfd, (cp = buf),
738 MKSH_HS_BUFSIZ)) == -1) {
739 if (errno == EINTR) {
740 intrcheck();
741 continue;
742 }
743 goto copy_error;
744 }
745 mis -= n;
746 while (n) {
747 if (intrsig)
748 goto has_intrsig;
749 if ((w = write(histfd, cp, n)) != -1) {
750 n -= w;
751 cp += w;
752 continue;
753 }
754 if (errno == EINTR) {
755 has_intrsig:
756 intrcheck();
757 continue;
758 }
759 goto copy_error;
760 }
761 }
762 if (ftruncate(histfd, tot)) {
763 copy_error:
764 rv = 1;
765 }
766 free_osfunc(buf);
767 return (rv);
768 }
769
770 static void
hist_persist_init(void)771 hist_persist_init(void)
772 {
773 unsigned char *base;
774 int lines, fd;
775 enum { hist_init_first, hist_init_retry, hist_use_it } hs;
776
777 if (((hname = str_val(global("HISTFILE"))) == NULL) || !*hname) {
778 hname = NULL;
779 return;
780 }
781 strdupx(hname, hname, APERM);
782 hs = hist_init_first;
783
784 retry:
785 /* we have a file and are interactive */
786 if ((fd = binopen3(hname, O_RDWR | O_CREAT | O_APPEND, 0600)) < 0)
787 return;
788 if ((histfd = savefd(fd)) < 0)
789 return;
790 if (histfd != fd)
791 close(fd);
792
793 mksh_lockfd(histfd);
794
795 histfsize = lseek(histfd, (off_t)0, SEEK_END);
796 if (histfsize > MKSH_MAXHISTFSIZE) {
797 /* we ignore too large files but still append to them */
798 goto hist_init_tail;
799 } else if (histfsize > 2) {
800 /* we have some data, check its validity */
801 base = (void *)mmap(NULL, (size_t)histfsize, PROT_READ,
802 MAP_FILE | MAP_PRIVATE, histfd, (off_t)0);
803 if (base == (unsigned char *)MAP_FAILED)
804 goto hist_init_fail;
805 if (base[0] != HMAGIC1 || base[1] != HMAGIC2) {
806 munmap(caddr_cast(base), (size_t)histfsize);
807 goto hist_init_fail;
808 }
809 /* load _all_ data */
810 lines = histload(hist_source, base + 2, (size_t)histfsize - 2);
811 munmap(caddr_cast(base), (size_t)histfsize);
812 /* check if the file needs to be truncated */
813 if (lines > histsize && histptr >= history) {
814 /* you're fucked up with the current code, trust me */
815 char *nhname, **hp;
816 struct stat sb;
817
818 /* create temporary file */
819 nhname = shf_smprintf("%s.%d", hname, (int)procpid);
820 if ((fd = binopen3(nhname, O_RDWR | O_CREAT | O_TRUNC |
821 O_EXCL, 0600)) < 0) {
822 /* just don't truncate then, meh. */
823 hs = hist_use_it;
824 goto hist_trunc_dont;
825 }
826 if (fstat(histfd, &sb) >= 0 &&
827 chown(nhname, sb.st_uid, sb.st_gid)) {
828 /* abort the truncation then, meh. */
829 goto hist_trunc_abort;
830 }
831 /* we definitively want some magic in that file */
832 if (write(fd, sprinkle, 2) != 2)
833 goto hist_trunc_abort;
834 /* and of course the entries */
835 hp = history;
836 while (hp < histptr) {
837 if (!writehistline(fd,
838 hist_source->line - (histptr - hp), *hp))
839 goto hist_trunc_abort;
840 ++hp;
841 }
842 /* now transfer back */
843 if (!hist_persist_back(fd)) {
844 /* success! */
845 hs = hist_use_it;
846 }
847 hist_trunc_abort:
848 /* remove temporary file */
849 close(fd);
850 fd = -1;
851 unlink(nhname);
852 /* use whatever is in the file now */
853 hist_trunc_dont:
854 afree(nhname, ATEMP);
855 if (hs == hist_use_it)
856 goto hist_trunc_done;
857 goto hist_init_fail;
858 }
859 } else if (histfsize != 0) {
860 /* negative or too small... */
861 hist_init_fail:
862 /* ... or mmap failed or illegal */
863 hist_finish();
864 /* nuke the bogus file then retry, at most once */
865 if (!unlink(hname) && hs != hist_init_retry) {
866 hs = hist_init_retry;
867 goto retry;
868 }
869 if (hs != hist_init_retry)
870 bi_errorf(Tf_cant_ss_s,
871 "unlink HISTFILE", hname, cstrerror(errno));
872 histfsize = 0;
873 return;
874 } else {
875 /* size 0, add magic to the history file */
876 if (write(histfd, sprinkle, 2) != 2) {
877 hist_finish();
878 return;
879 }
880 }
881 hist_trunc_done:
882 if ((histfsize = lseek(histfd, (off_t)0, SEEK_END)) < 0)
883 goto hist_init_fail;
884 hist_init_tail:
885 mksh_unlkfd(histfd);
886 }
887 #endif
888
889 void
hist_init(Source * s)890 hist_init(Source *s)
891 {
892 histsave(NULL, NULL, HIST_DISCARD, true);
893
894 if (Flag(FTALKING) == 0)
895 return;
896
897 hstarted = true;
898 hist_source = s;
899
900 #if HAVE_PERSISTENT_HISTORY
901 hist_persist_init();
902 #endif
903 }
904
905 #if HAVE_PERSISTENT_HISTORY
906 /*
907 * load the history structure from the stored data
908 */
909 static int
histload(Source * s,unsigned char * base,size_t bytes)910 histload(Source *s, unsigned char *base, size_t bytes)
911 {
912 int lno = 0, lines = 0;
913 unsigned char *cp;
914
915 histload_loop:
916 /* !bytes check as some systems (older FreeBSDs) have buggy memchr */
917 if (!bytes || (cp = memchr(base, COMMAND, bytes)) == NULL)
918 return (lines);
919 /* advance base pointer past COMMAND byte */
920 bytes -= ++cp - base;
921 base = cp;
922 /* if there is no full string left, don't bother with the rest */
923 if (bytes < 5 || (cp = memchr(base + 4, '\0', bytes - 4)) == NULL)
924 return (lines);
925 /* load the stored line number */
926 lno = ((base[0] & 0xFF) << 24) | ((base[1] & 0xFF) << 16) |
927 ((base[2] & 0xFF) << 8) | (base[3] & 0xFF);
928 /* store away the found line (@base[4]) */
929 ++lines;
930 if (histptr >= history && lno - 1 != s->line) {
931 /* a replacement? */
932 char **hp;
933
934 if (lno >= s->line - (histptr - history) && lno <= s->line) {
935 hp = &histptr[lno - s->line];
936 afree(*hp, APERM);
937 strdupx(*hp, (char *)(base + 4), APERM);
938 }
939 } else {
940 s->line = lno--;
941 histsave(&lno, (char *)(base + 4), HIST_NOTE, false);
942 }
943 /* advance base pointer past NUL */
944 bytes -= ++cp - base;
945 base = cp;
946 /* repeat until no more */
947 goto histload_loop;
948 }
949
950 /*
951 * write a command to the end of the history file
952 *
953 * This *MAY* seem easy but it's also necessary to check
954 * that the history file has not changed in size.
955 * If it has - then some other shell has written to it and
956 * we should (re)read those commands to update our history
957 */
958 static void
writehistfile(int lno,const char * cmd)959 writehistfile(int lno, const char *cmd)
960 {
961 off_t sizenow;
962 size_t bytes;
963 unsigned char *base, *news;
964
965 mksh_lockfd(histfd);
966 if ((sizenow = lseek(histfd, (off_t)0, SEEK_END)) < 0)
967 goto bad;
968 else if (sizenow < histfsize) {
969 /* the file has shrunk; trust it just appending the new data */
970 /* well, for now, anyway… since mksh strdups all into memory */
971 /* we can use a nicer approach some time later… */
972 ;
973 } else if (
974 /* ignore changes when the file is too large */
975 sizenow <= MKSH_MAXHISTFSIZE
976 &&
977 /* the size has changed, we need to do read updates */
978 sizenow > histfsize
979 ) {
980 /* both sizenow and histfsize are <= MKSH_MAXHISTFSIZE */
981 bytes = (size_t)(sizenow - histfsize);
982 base = (void *)mmap(NULL, (size_t)sizenow, PROT_READ,
983 MAP_FILE | MAP_PRIVATE, histfd, (off_t)0);
984 if (base == (unsigned char *)MAP_FAILED)
985 goto bad;
986 news = base + (size_t)histfsize;
987 if (*news == COMMAND) {
988 hist_source->line--;
989 histload(hist_source, news, bytes);
990 hist_source->line++;
991 lno = hist_source->line;
992 } else
993 bytes = 0;
994 munmap(caddr_cast(base), (size_t)sizenow);
995 if (!bytes)
996 goto bad;
997 }
998 if (cmd && !writehistline(histfd, lno, cmd)) {
999 bad:
1000 hist_finish();
1001 return;
1002 }
1003 if ((histfsize = lseek(histfd, (off_t)0, SEEK_END)) < 0)
1004 goto bad;
1005 mksh_unlkfd(histfd);
1006 }
1007
1008 static int
writehistline(int fd,int lno,const char * cmd)1009 writehistline(int fd, int lno, const char *cmd)
1010 {
1011 ssize_t n;
1012 unsigned char hdr[5];
1013
1014 hdr[0] = COMMAND;
1015 hdr[1] = (lno >> 24) & 0xFF;
1016 hdr[2] = (lno >> 16) & 0xFF;
1017 hdr[3] = (lno >> 8) & 0xFF;
1018 hdr[4] = lno & 0xFF;
1019 n = strlen(cmd) + 1;
1020 return (write(fd, hdr, 5) == 5 && write(fd, cmd, n) == n);
1021 }
1022
1023 void
hist_finish(void)1024 hist_finish(void)
1025 {
1026 if (histfd >= 0) {
1027 mksh_unlkfd(histfd);
1028 (void)close(histfd);
1029 }
1030 histfd = -1;
1031 }
1032 #endif
1033
1034
1035 #if !HAVE_SYS_SIGNAME
1036 static const struct mksh_sigpair {
1037 const char * const name;
1038 int nr;
1039 } mksh_sigpairs[] = {
1040 #include "signames.inc"
1041 { NULL, 0 }
1042 };
1043 #endif
1044
1045 #if HAVE_SYS_SIGLIST
1046 #if !HAVE_SYS_SIGLIST_DECL
1047 extern const char * const sys_siglist[];
1048 #endif
1049 #endif
1050
1051 void
inittraps(void)1052 inittraps(void)
1053 {
1054 int i;
1055 const char *cs;
1056 #if !HAVE_SYS_SIGNAME
1057 const struct mksh_sigpair *pair;
1058 #endif
1059
1060 trap_exstat = -1;
1061
1062 /* populate sigtraps based on sys_signame and sys_siglist */
1063 for (i = 1; i < ksh_NSIG; i++) {
1064 sigtraps[i].signal = i;
1065 #if HAVE_SYS_SIGNAME
1066 cs = sys_signame[i];
1067 #else
1068 pair = mksh_sigpairs;
1069 while ((pair->nr != i) && (pair->name != NULL))
1070 ++pair;
1071 cs = pair->name;
1072 #endif
1073 if ((cs == NULL) ||
1074 (cs[0] == '\0'))
1075 sigtraps[i].name = null;
1076 else {
1077 char *s;
1078
1079 /* this is not optimal, what about SIGSIG1? */
1080 if (ksh_eq(cs[0], 'S', 's') &&
1081 ksh_eq(cs[1], 'I', 'i') &&
1082 ksh_eq(cs[2], 'G', 'g') &&
1083 cs[3] != '\0') {
1084 /* skip leading "SIG" */
1085 cs += 3;
1086 }
1087 strdupx(s, cs, APERM);
1088 sigtraps[i].name = s;
1089 while ((*s = ksh_toupper(*s)))
1090 ++s;
1091 /* check for reserved names */
1092 if (!strcmp(sigtraps[i].name, "EXIT") ||
1093 !strcmp(sigtraps[i].name, "ERR")) {
1094 #ifndef MKSH_SMALL
1095 internal_warningf(Tinvname, sigtraps[i].name,
1096 "signal");
1097 #endif
1098 sigtraps[i].name = null;
1099 }
1100 }
1101 if (sigtraps[i].name == null)
1102 sigtraps[i].name = shf_smprintf(Tf_d, i);
1103 #if HAVE_SYS_SIGLIST
1104 sigtraps[i].mess = sys_siglist[i];
1105 #elif HAVE_STRSIGNAL
1106 sigtraps[i].mess = strsignal(i);
1107 #else
1108 sigtraps[i].mess = NULL;
1109 #endif
1110 if ((sigtraps[i].mess == NULL) ||
1111 (sigtraps[i].mess[0] == '\0'))
1112 sigtraps[i].mess = shf_smprintf(Tf_sd,
1113 "Signal", i);
1114 }
1115 sigtraps[ksh_SIGEXIT].signal = ksh_SIGEXIT;
1116 sigtraps[ksh_SIGEXIT].name = "EXIT";
1117 sigtraps[ksh_SIGEXIT].mess = "Exit trap";
1118 sigtraps[ksh_SIGERR].signal = ksh_SIGERR;
1119 sigtraps[ksh_SIGERR].name = "ERR";
1120 sigtraps[ksh_SIGERR].mess = "Error handler";
1121
1122 (void)sigemptyset(&Sigact_ign.sa_mask);
1123 Sigact_ign.sa_flags = 0; /* interruptible */
1124 Sigact_ign.sa_handler = SIG_IGN;
1125
1126 sigtraps[SIGINT].flags |= TF_DFL_INTR | TF_TTY_INTR;
1127 sigtraps[SIGQUIT].flags |= TF_DFL_INTR | TF_TTY_INTR;
1128 /* SIGTERM is not fatal for interactive */
1129 sigtraps[SIGTERM].flags |= TF_DFL_INTR;
1130 sigtraps[SIGHUP].flags |= TF_FATAL;
1131 sigtraps[SIGCHLD].flags |= TF_SHELL_USES;
1132
1133 /* these are always caught so we can clean up any temporary files. */
1134 setsig(&sigtraps[SIGINT], trapsig, SS_RESTORE_ORIG);
1135 setsig(&sigtraps[SIGQUIT], trapsig, SS_RESTORE_ORIG);
1136 setsig(&sigtraps[SIGTERM], trapsig, SS_RESTORE_ORIG);
1137 setsig(&sigtraps[SIGHUP], trapsig, SS_RESTORE_ORIG);
1138 }
1139
1140 static void alarm_catcher(int sig);
1141
1142 void
alarm_init(void)1143 alarm_init(void)
1144 {
1145 sigtraps[SIGALRM].flags |= TF_SHELL_USES;
1146 setsig(&sigtraps[SIGALRM], alarm_catcher,
1147 SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
1148 }
1149
1150 /* ARGSUSED */
1151 static void
alarm_catcher(int sig MKSH_A_UNUSED)1152 alarm_catcher(int sig MKSH_A_UNUSED)
1153 {
1154 /* this runs inside interrupt context, with errno saved */
1155
1156 if (ksh_tmout_state == TMOUT_READING) {
1157 int left = alarm(0);
1158
1159 if (left == 0) {
1160 ksh_tmout_state = TMOUT_LEAVING;
1161 intrsig = 1;
1162 } else
1163 alarm(left);
1164 }
1165 }
1166
1167 Trap *
gettrap(const char * cs,bool igncase,bool allsigs)1168 gettrap(const char *cs, bool igncase, bool allsigs)
1169 {
1170 int i;
1171 Trap *p;
1172 char *as;
1173
1174 /* signal number (1..ksh_NSIG) or 0? */
1175
1176 if (ctype(*cs, C_DIGIT))
1177 return ((getn(cs, &i) && 0 <= i && i < ksh_NSIG) ?
1178 (&sigtraps[i]) : NULL);
1179
1180 /* do a lookup by name then */
1181
1182 /* this breaks SIGSIG1, but we do that above anyway */
1183 if (ksh_eq(cs[0], 'S', 's') &&
1184 ksh_eq(cs[1], 'I', 'i') &&
1185 ksh_eq(cs[2], 'G', 'g') &&
1186 cs[3] != '\0') {
1187 /* skip leading "SIG" */
1188 cs += 3;
1189 }
1190 if (igncase) {
1191 char *s;
1192
1193 strdupx(as, cs, ATEMP);
1194 cs = s = as;
1195 while ((*s = ksh_toupper(*s)))
1196 ++s;
1197 } else
1198 as = NULL;
1199
1200 /* this is idiotic, we really want a hashtable here */
1201
1202 p = sigtraps;
1203 i = ksh_NSIG + 1;
1204 do {
1205 if (!strcmp(p->name, cs))
1206 goto found;
1207 ++p;
1208 } while (--i);
1209 goto notfound;
1210
1211 found:
1212 if (!allsigs) {
1213 if (p->signal == ksh_SIGEXIT || p->signal == ksh_SIGERR) {
1214 notfound:
1215 p = NULL;
1216 }
1217 }
1218 afree(as, ATEMP);
1219 return (p);
1220 }
1221
1222 /*
1223 * trap signal handler
1224 */
1225 void
trapsig(int i)1226 trapsig(int i)
1227 {
1228 Trap *p = &sigtraps[i];
1229 int eno = errno;
1230
1231 trap = p->set = 1;
1232 if (p->flags & TF_DFL_INTR)
1233 intrsig = 1;
1234 if ((p->flags & TF_FATAL) && !p->trap) {
1235 fatal_trap = 1;
1236 intrsig = 1;
1237 }
1238 if (p->shtrap)
1239 (*p->shtrap)(i);
1240 errno = eno;
1241 }
1242
1243 /*
1244 * called when we want to allow the user to ^C out of something - won't
1245 * work if user has trapped SIGINT.
1246 */
1247 void
intrcheck(void)1248 intrcheck(void)
1249 {
1250 if (intrsig)
1251 runtraps(TF_DFL_INTR|TF_FATAL);
1252 }
1253
1254 /*
1255 * called after EINTR to check if a signal with normally causes process
1256 * termination has been received.
1257 */
1258 int
fatal_trap_check(void)1259 fatal_trap_check(void)
1260 {
1261 Trap *p = sigtraps;
1262 int i = ksh_NSIG + 1;
1263
1264 /* todo: should check if signal is fatal, not the TF_DFL_INTR flag */
1265 do {
1266 if (p->set && (p->flags & (TF_DFL_INTR|TF_FATAL)))
1267 /* return value is used as an exit code */
1268 return (ksh_sigmask(p->signal));
1269 ++p;
1270 } while (--i);
1271 return (0);
1272 }
1273
1274 /*
1275 * Returns the signal number of any pending traps: ie, a signal which has
1276 * occurred for which a trap has been set or for which the TF_DFL_INTR flag
1277 * is set.
1278 */
1279 int
trap_pending(void)1280 trap_pending(void)
1281 {
1282 Trap *p = sigtraps;
1283 int i = ksh_NSIG + 1;
1284
1285 do {
1286 if (p->set && ((p->trap && p->trap[0]) ||
1287 ((p->flags & (TF_DFL_INTR|TF_FATAL)) && !p->trap)))
1288 return (p->signal);
1289 ++p;
1290 } while (--i);
1291 return (0);
1292 }
1293
1294 /*
1295 * run any pending traps. If intr is set, only run traps that
1296 * can interrupt commands.
1297 */
1298 void
runtraps(int flag)1299 runtraps(int flag)
1300 {
1301 Trap *p = sigtraps;
1302 int i = ksh_NSIG + 1;
1303
1304 if (ksh_tmout_state == TMOUT_LEAVING) {
1305 ksh_tmout_state = TMOUT_EXECUTING;
1306 warningf(false, "timed out waiting for input");
1307 unwind(LEXIT);
1308 } else
1309 /*
1310 * XXX: this means the alarm will have no effect if a trap
1311 * is caught after the alarm() was started...not good.
1312 */
1313 ksh_tmout_state = TMOUT_EXECUTING;
1314 if (!flag)
1315 trap = 0;
1316 if (flag & TF_DFL_INTR)
1317 intrsig = 0;
1318 if (flag & TF_FATAL)
1319 fatal_trap = 0;
1320 ++trap_nested;
1321 do {
1322 if (p->set && (!flag ||
1323 ((p->flags & flag) && p->trap == NULL)))
1324 runtrap(p, false);
1325 ++p;
1326 } while (--i);
1327 if (!--trap_nested)
1328 runtrap(NULL, true);
1329 }
1330
1331 void
runtrap(Trap * p,bool is_last)1332 runtrap(Trap *p, bool is_last)
1333 {
1334 int old_changed = 0, i;
1335 char *trapstr;
1336
1337 if (p == NULL)
1338 /* just clean up, see runtraps() above */
1339 goto donetrap;
1340 i = p->signal;
1341 trapstr = p->trap;
1342 p->set = 0;
1343 if (trapstr == NULL) {
1344 /* SIG_DFL */
1345 if (p->flags & (TF_FATAL | TF_DFL_INTR)) {
1346 exstat = (int)(128U + (unsigned)i);
1347 if ((unsigned)exstat > 255U)
1348 exstat = 255;
1349 }
1350 /* e.g. SIGHUP */
1351 if (p->flags & TF_FATAL)
1352 unwind(LLEAVE);
1353 /* e.g. SIGINT, SIGQUIT, SIGTERM, etc. */
1354 if (p->flags & TF_DFL_INTR)
1355 unwind(LINTR);
1356 goto donetrap;
1357 }
1358 if (trapstr[0] == '\0')
1359 /* SIG_IGN */
1360 goto donetrap;
1361 if (i == ksh_SIGEXIT || i == ksh_SIGERR) {
1362 /* avoid recursion on these */
1363 old_changed = p->flags & TF_CHANGED;
1364 p->flags &= ~TF_CHANGED;
1365 p->trap = NULL;
1366 }
1367 if (trap_exstat == -1)
1368 trap_exstat = exstat & 0xFF;
1369 /*
1370 * Note: trapstr is fully parsed before anything is executed, thus
1371 * no problem with afree(p->trap) in settrap() while still in use.
1372 */
1373 command(trapstr, current_lineno);
1374 if (i == ksh_SIGEXIT || i == ksh_SIGERR) {
1375 if (p->flags & TF_CHANGED)
1376 /* don't clear TF_CHANGED */
1377 afree(trapstr, APERM);
1378 else
1379 p->trap = trapstr;
1380 p->flags |= old_changed;
1381 }
1382
1383 donetrap:
1384 /* we're the last trap of a sequence executed */
1385 if (is_last && trap_exstat != -1) {
1386 exstat = trap_exstat;
1387 trap_exstat = -1;
1388 }
1389 }
1390
1391 /* clear pending traps and reset user's trap handlers; used after fork(2) */
1392 void
cleartraps(void)1393 cleartraps(void)
1394 {
1395 Trap *p = sigtraps;
1396 int i = ksh_NSIG + 1;
1397
1398 trap = 0;
1399 intrsig = 0;
1400 fatal_trap = 0;
1401
1402 do {
1403 p->set = 0;
1404 if ((p->flags & TF_USER_SET) && (p->trap && p->trap[0]))
1405 settrap(p, NULL);
1406 ++p;
1407 } while (--i);
1408 }
1409
1410 /* restore signals just before an exec(2) */
1411 void
restoresigs(void)1412 restoresigs(void)
1413 {
1414 Trap *p = sigtraps;
1415 int i = ksh_NSIG + 1;
1416
1417 do {
1418 if (p->flags & (TF_EXEC_IGN|TF_EXEC_DFL))
1419 setsig(p, (p->flags & TF_EXEC_IGN) ? SIG_IGN : SIG_DFL,
1420 SS_RESTORE_CURR|SS_FORCE);
1421 ++p;
1422 } while (--i);
1423 }
1424
1425 void
settrap(Trap * p,const char * s)1426 settrap(Trap *p, const char *s)
1427 {
1428 sig_t f;
1429
1430 afree(p->trap, APERM);
1431 /* handles s == NULL */
1432 strdupx(p->trap, s, APERM);
1433 p->flags |= TF_CHANGED;
1434 f = !s ? SIG_DFL : s[0] ? trapsig : SIG_IGN;
1435
1436 p->flags |= TF_USER_SET;
1437 if ((p->flags & (TF_DFL_INTR|TF_FATAL)) && f == SIG_DFL)
1438 f = trapsig;
1439 else if (p->flags & TF_SHELL_USES) {
1440 if (!(p->flags & TF_ORIG_IGN) || Flag(FTALKING)) {
1441 /* do what user wants at exec time */
1442 p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
1443 if (f == SIG_IGN)
1444 p->flags |= TF_EXEC_IGN;
1445 else
1446 p->flags |= TF_EXEC_DFL;
1447 }
1448
1449 /*
1450 * assumes handler already set to what shell wants it
1451 * (normally trapsig, but could be j_sigchld() or SIG_IGN)
1452 */
1453 return;
1454 }
1455
1456 /* todo: should we let user know signal is ignored? how? */
1457 setsig(p, f, SS_RESTORE_CURR|SS_USER);
1458 }
1459
1460 /*
1461 * called by c_print() when writing to a co-process to ensure
1462 * SIGPIPE won't kill shell (unless user catches it and exits)
1463 */
1464 bool
block_pipe(void)1465 block_pipe(void)
1466 {
1467 bool restore_dfl = false;
1468 Trap *p = &sigtraps[SIGPIPE];
1469
1470 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
1471 setsig(p, SIG_IGN, SS_RESTORE_CURR);
1472 if (p->flags & TF_ORIG_DFL)
1473 restore_dfl = true;
1474 } else if (p->cursig == SIG_DFL) {
1475 setsig(p, SIG_IGN, SS_RESTORE_CURR);
1476 /* restore to SIG_DFL */
1477 restore_dfl = true;
1478 }
1479 return (restore_dfl);
1480 }
1481
1482 /* called by c_print() to undo whatever block_pipe() did */
1483 void
restore_pipe(void)1484 restore_pipe(void)
1485 {
1486 setsig(&sigtraps[SIGPIPE], SIG_DFL, SS_RESTORE_CURR);
1487 }
1488
1489 /*
1490 * Set action for a signal. Action may not be set if original
1491 * action was SIG_IGN, depending on the value of flags and FTALKING.
1492 */
1493 int
setsig(Trap * p,sig_t f,int flags)1494 setsig(Trap *p, sig_t f, int flags)
1495 {
1496 struct sigaction sigact;
1497
1498 if (p->signal == ksh_SIGEXIT || p->signal == ksh_SIGERR)
1499 return (1);
1500
1501 memset(&sigact, 0, sizeof(sigact));
1502
1503 /*
1504 * First time setting this signal? If so, get and note the current
1505 * setting.
1506 */
1507 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
1508 sigaction(p->signal, &Sigact_ign, &sigact);
1509 p->flags |= sigact.sa_handler == SIG_IGN ?
1510 TF_ORIG_IGN : TF_ORIG_DFL;
1511 p->cursig = SIG_IGN;
1512 }
1513
1514 /*-
1515 * Generally, an ignored signal stays ignored, except if
1516 * - the user of an interactive shell wants to change it
1517 * - the shell wants for force a change
1518 */
1519 if ((p->flags & TF_ORIG_IGN) && !(flags & SS_FORCE) &&
1520 (!(flags & SS_USER) || !Flag(FTALKING)))
1521 return (0);
1522
1523 setexecsig(p, flags & SS_RESTORE_MASK);
1524
1525 /*
1526 * This is here 'cause there should be a way of clearing
1527 * shtraps, but don't know if this is a sane way of doing
1528 * it. At the moment, all users of shtrap are lifetime
1529 * users (SIGALRM, SIGCHLD, SIGWINCH).
1530 */
1531 if (!(flags & SS_USER))
1532 p->shtrap = (sig_t)NULL;
1533 if (flags & SS_SHTRAP) {
1534 p->shtrap = f;
1535 f = trapsig;
1536 }
1537
1538 if (p->cursig != f) {
1539 p->cursig = f;
1540 (void)sigemptyset(&sigact.sa_mask);
1541 /* interruptible */
1542 sigact.sa_flags = 0;
1543 sigact.sa_handler = f;
1544 sigaction(p->signal, &sigact, NULL);
1545 }
1546
1547 return (1);
1548 }
1549
1550 /* control what signal is set to before an exec() */
1551 void
setexecsig(Trap * p,int restore)1552 setexecsig(Trap *p, int restore)
1553 {
1554 /* XXX debugging */
1555 if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL)))
1556 internal_errorf("setexecsig: unset signal %d(%s)",
1557 p->signal, p->name);
1558
1559 /* restore original value for exec'd kids */
1560 p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
1561 switch (restore & SS_RESTORE_MASK) {
1562 case SS_RESTORE_CURR:
1563 /* leave things as they currently are */
1564 break;
1565 case SS_RESTORE_ORIG:
1566 p->flags |= p->flags & TF_ORIG_IGN ? TF_EXEC_IGN : TF_EXEC_DFL;
1567 break;
1568 case SS_RESTORE_DFL:
1569 p->flags |= TF_EXEC_DFL;
1570 break;
1571 case SS_RESTORE_IGN:
1572 p->flags |= TF_EXEC_IGN;
1573 break;
1574 }
1575 }
1576
1577 #if HAVE_PERSISTENT_HISTORY || defined(DF)
1578 /*
1579 * File descriptor locking and unlocking functions.
1580 * Could use some error handling, but hey, this is only
1581 * advisory locking anyway, will often not work over NFS,
1582 * and you are SOL if this fails...
1583 */
1584
1585 void
mksh_lockfd(int fd)1586 mksh_lockfd(int fd)
1587 {
1588 #if defined(__OpenBSD__)
1589 /* flock is not interrupted by signals */
1590 (void)flock(fd, LOCK_EX);
1591 #elif HAVE_FLOCK
1592 int rv;
1593
1594 /* e.g. on Linux */
1595 do {
1596 rv = flock(fd, LOCK_EX);
1597 } while (rv == 1 && errno == EINTR);
1598 #elif HAVE_LOCK_FCNTL
1599 int rv;
1600 struct flock lks;
1601
1602 memset(&lks, 0, sizeof(lks));
1603 lks.l_type = F_WRLCK;
1604 do {
1605 rv = fcntl(fd, F_SETLKW, &lks);
1606 } while (rv == 1 && errno == EINTR);
1607 #endif
1608 }
1609
1610 /* designed to not define mksh_unlkfd if none triggered */
1611 #if HAVE_FLOCK
1612 void
mksh_unlkfd(int fd)1613 mksh_unlkfd(int fd)
1614 {
1615 (void)flock(fd, LOCK_UN);
1616 }
1617 #elif HAVE_LOCK_FCNTL
1618 void
mksh_unlkfd(int fd)1619 mksh_unlkfd(int fd)
1620 {
1621 struct flock lks;
1622
1623 memset(&lks, 0, sizeof(lks));
1624 lks.l_type = F_UNLCK;
1625 (void)fcntl(fd, F_SETLKW, &lks);
1626 }
1627 #endif
1628 #endif
1629