1 /*        $NetBSD: error.c,v 1.45 2023/03/19 17:55:57 kre Exp $       */
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *        The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)error.c     8.2 (Berkeley) 5/4/95";
39 #else
40 __RCSID("$NetBSD: error.c,v 1.45 2023/03/19 17:55:57 kre Exp $");
41 #endif
42 #endif /* not lint */
43 
44 /*
45  * Errors and exceptions.
46  */
47 
48 #include <signal.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 #include <errno.h>
52 #include <stdio.h>
53 #include <string.h>
54 
55 #include "shell.h"
56 #include "eval.h" /* for commandname */
57 #include "main.h"
58 #include "options.h"
59 #include "output.h"
60 #include "error.h"
61 #include "show.h"
62 
63 
64 /*
65  * Code to handle exceptions in C.
66  */
67 
68 struct jmploc *handler;
69 int exception;
70 volatile int suppressint;
71 volatile int intpending;
72 volatile int errors_suppressed;
73 const char * volatile currentcontext;
74 
75 
76 
77 static void exverror(int, const char *, va_list) __dead;
78 
79 /*
80  * Called to raise an exception.  Since C doesn't include exceptions, we
81  * just do a longjmp to the exception handler.  The type of exception is
82  * stored in the global variable "exception".
83  */
84 
85 void
exraise(int e)86 exraise(int e)
87 {
88           CTRACE(DBG_ERRS, ("exraise(%d)\n", e));
89           if (handler == NULL)
90                     abort();
91           exception = e;
92           longjmp(handler->loc, 1);
93 }
94 
95 
96 /*
97  * Called from trap.c when a SIGINT is received.  (If the user specifies
98  * that SIGINT is to be trapped or ignored using the trap builtin, then
99  * this routine is not called.)  Suppressint is nonzero when interrupts
100  * are held using the INTOFF macro.  The call to _exit is necessary because
101  * there is a short period after a fork before the signal handlers are
102  * set to the appropriate value for the child.  (The test for iflag is
103  * just defensive programming.)
104  */
105 
106 void
onint(void)107 onint(void)
108 {
109           sigset_t nsigset;
110 
111           if (suppressint) {
112                     intpending = 1;
113                     return;
114           }
115           intpending = 0;
116           sigemptyset(&nsigset);
117           sigprocmask(SIG_SETMASK, &nsigset, NULL);
118           if (rootshell && iflag)
119                     exraise(EXINT);
120           else {
121                     signal(SIGINT, SIG_DFL);
122                     raise(SIGINT);
123           }
124           /* NOTREACHED */
125 }
126 
127 static __printflike(2, 0) void
exvwarning(int sv_errno,const char * msg,va_list ap)128 exvwarning(int sv_errno, const char *msg, va_list ap)
129 {
130           /* Partially emulate line buffered output so that:
131            *        printf '%d\n' 1 a 2
132            * and
133            *        printf '%d %d %d\n' 1 a 2
134            * both generate sensible text when stdout and stderr are merged.
135            */
136           if (output.buf != NULL && output.nextc != output.buf &&
137               output.nextc[-1] == '\n')
138                     flushout(&output);
139 
140           if (errors_suppressed)
141                     return;
142 
143           if (commandname)
144                     outfmt(&errout, "%s: ", commandname);
145           else
146                     outfmt(&errout, "%s: ", getprogname());
147           if (currentcontext != NULL)
148                     outfmt(&errout, "%s: ", currentcontext);
149           if (msg != NULL) {
150                     doformat(&errout, msg, ap);
151                     if (sv_errno >= 0)
152                               outfmt(&errout, ": ");
153           }
154           if (sv_errno >= 0)
155                     outfmt(&errout, "%s", strerror(sv_errno));
156           out2c('\n');
157           flushout(&errout);
158 }
159 
160 /*
161  * Exverror is called to raise the error exception.  If the second argument
162  * is not NULL then error prints an error message using printf style
163  * formatting.  It then raises the error exception.
164  */
165 static __printflike(2, 0) void
exverror(int cond,const char * msg,va_list ap)166 exverror(int cond, const char *msg, va_list ap)
167 {
168           CLEAR_PENDING_INT;
169           INTOFF;
170 
171 #ifdef DEBUG
172           if (msg) {
173                     CTRACE(DBG_ERRS, ("exverror(%d, \"", cond));
174                     CTRACEV(DBG_ERRS, (msg, ap));
175                     CTRACE(DBG_ERRS, ("\") pid=%d\n", getpid()));
176           } else
177                     CTRACE(DBG_ERRS, ("exverror(%d, NULL) pid=%d\n", cond,
178                         getpid()));
179 #endif
180           if (msg)
181                     exvwarning(-1, msg, ap);
182 
183           flushall();
184           exraise(cond);
185           /* NOTREACHED */
186 }
187 
188 
189 void
error(const char * msg,...)190 error(const char *msg, ...)
191 {
192           va_list ap;
193 
194           /*
195            * On error, we certainly never want exit(0)...
196            */
197           if (exerrno == 0)
198                     exerrno = 1;
199           va_start(ap, msg);
200           exverror(EXERROR, msg, ap);
201           /* NOTREACHED */
202           va_end(ap);
203 }
204 
205 
206 void
exerror(int cond,const char * msg,...)207 exerror(int cond, const char *msg, ...)
208 {
209           va_list ap;
210 
211           va_start(ap, msg);
212           exverror(cond, msg, ap);
213           /* NOTREACHED */
214           va_end(ap);
215 }
216 
217 /*
218  * error/warning routines for external builtins
219  */
220 
221 void
sh_exit(int rval)222 sh_exit(int rval)
223 {
224           VTRACE(DBG_ERRS|DBG_PROCS|DBG_CMDS, ("sh_exit(%d)\n", rval));
225           exerrno = rval & 255;
226           exraise(EXEXEC);
227 }
228 
229 void
sh_err(int status,const char * fmt,...)230 sh_err(int status, const char *fmt, ...)
231 {
232           va_list ap;
233 
234           va_start(ap, fmt);
235           exvwarning(errno, fmt, ap);
236           va_end(ap);
237           sh_exit(status);
238 }
239 
240 void
sh_verr(int status,const char * fmt,va_list ap)241 sh_verr(int status, const char *fmt, va_list ap)
242 {
243           exvwarning(errno, fmt, ap);
244           sh_exit(status);
245 }
246 
247 void
sh_errx(int status,const char * fmt,...)248 sh_errx(int status, const char *fmt, ...)
249 {
250           va_list ap;
251 
252           va_start(ap, fmt);
253           exvwarning(-1, fmt, ap);
254           va_end(ap);
255           sh_exit(status);
256 }
257 
258 void
sh_verrx(int status,const char * fmt,va_list ap)259 sh_verrx(int status, const char *fmt, va_list ap)
260 {
261           exvwarning(-1, fmt, ap);
262           sh_exit(status);
263 }
264 
265 void
sh_warn(const char * fmt,...)266 sh_warn(const char *fmt, ...)
267 {
268           va_list ap;
269 
270           va_start(ap, fmt);
271           exvwarning(errno, fmt, ap);
272           va_end(ap);
273 }
274 
275 void
sh_vwarn(const char * fmt,va_list ap)276 sh_vwarn(const char *fmt, va_list ap)
277 {
278           exvwarning(errno, fmt, ap);
279 }
280 
281 void
sh_warnx(const char * fmt,...)282 sh_warnx(const char *fmt, ...)
283 {
284           va_list ap;
285 
286           va_start(ap, fmt);
287           exvwarning(-1, fmt, ap);
288           va_end(ap);
289 }
290 
291 void
sh_vwarnx(const char * fmt,va_list ap)292 sh_vwarnx(const char *fmt, va_list ap)
293 {
294           exvwarning(-1, fmt, ap);
295 }
296 
297 
298 /*
299  * Table of error messages.
300  */
301 
302 struct errname {
303           short errcode;                /* error number */
304           short action;                 /* operation which encountered the error */
305           const char *msg;    /* text describing the error */
306 };
307 
308 
309 #define ALL (E_OPEN|E_CREAT|E_EXEC)
310 
311 STATIC const struct errname errormsg[] = {
312           { EINTR,  ALL,      "interrupted" },
313           { EACCES, E_EXEC,   "no execute permission" },
314           { EACCES, ALL,      "permission denied" },
315           { EIO,              ALL,      "I/O error" },
316           { EEXIST, ALL,      "file exists" },
317           { ENOENT, E_OPEN,   "no such file" },
318           { ENOENT, E_CREAT,"directory nonexistent" },
319           { ENOENT, E_EXEC,   "not found" },
320           { ENOTDIR,          E_OPEN,   "no such file" },
321           { ENOTDIR,          E_CREAT,"directory nonexistent" },
322           { ENOTDIR,          E_EXEC,   "not found" },
323           { EISDIR, ALL,      "is a directory" },
324 #ifdef EMFILE
325           { EMFILE, ALL,      "too many open files" },
326 #endif
327           { ENFILE, ALL,      "file table overflow" },
328           { ENOSPC, ALL,      "file system full" },
329 #ifdef EDQUOT
330           { EDQUOT, ALL,      "disk quota exceeded" },
331 #endif
332 #ifdef ENOSR
333           { ENOSR,  ALL,      "no streams resources" },
334 #endif
335           { ENXIO,  ALL,      "no such device or address" },
336           { EROFS,  ALL,      "read-only file system" },
337           { ETXTBSY,          ALL,      "text busy" },
338 #ifdef EAGAIN
339           { EAGAIN, E_EXEC,   "not enough memory" },
340 #endif
341           { ENOMEM, ALL,      "not enough memory" },
342 #ifdef ENOLINK
343           { ENOLINK,          ALL,      "remote access failed" },
344 #endif
345 #ifdef EMULTIHOP
346           { EMULTIHOP,        ALL,      "remote access failed" },
347 #endif
348 #ifdef ECOMM
349           { ECOMM,  ALL,      "remote access failed" },
350 #endif
351 #ifdef ESTALE
352           { ESTALE, ALL,      "remote access failed" },
353 #endif
354 #ifdef ETIMEDOUT
355           { ETIMEDOUT,        ALL,      "remote access failed" },
356 #endif
357 #ifdef ELOOP
358           { ELOOP,  ALL,      "symbolic link loop" },
359 #endif
360 #ifdef ENAMETOOLONG
361           { ENAMETOOLONG,     ALL,      "file name too long" },
362 #endif
363           { E2BIG,  E_EXEC,   "argument list too long" },
364 #ifdef ELIBACC
365           { ELIBACC,          E_EXEC,   "shared library missing" },
366 #endif
367           { 0,                0,        NULL },
368 };
369 
370 
371 /*
372  * Return a string describing an error.  The returned string may be a
373  * pointer to a static buffer that will be overwritten on the next call.
374  * Action describes the operation that got the error.
375  */
376 
377 const char *
errmsg(int e,int action)378 errmsg(int e, int action)
379 {
380           struct errname const *ep;
381           static char buf[12];
382 
383           for (ep = errormsg ; ep->errcode ; ep++) {
384                     if (ep->errcode == e && (ep->action & action) != 0)
385                               return ep->msg;
386           }
387           fmtstr(buf, sizeof buf, "error %d", e);
388           return buf;
389 }
390