xref: /netbsd-src/bin/sh/error.c (revision 53d1339bf7f9c7367b35a9e1ebe693f9b047a47b)
1 /*	$NetBSD: error.c,v 1.43 2019/02/04 11:16:41 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 1.43 2019/02/04 11:16:41 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
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
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
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
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
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
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
222 sh_exit(int rval)
223 {
224 	exerrno = rval & 255;
225 	exraise(EXEXEC);
226 }
227 
228 void
229 sh_err(int status, const char *fmt, ...)
230 {
231 	va_list ap;
232 
233 	va_start(ap, fmt);
234 	exvwarning(errno, fmt, ap);
235 	va_end(ap);
236 	sh_exit(status);
237 }
238 
239 void
240 sh_verr(int status, const char *fmt, va_list ap)
241 {
242 	exvwarning(errno, fmt, ap);
243 	sh_exit(status);
244 }
245 
246 void
247 sh_errx(int status, const char *fmt, ...)
248 {
249 	va_list ap;
250 
251 	va_start(ap, fmt);
252 	exvwarning(-1, fmt, ap);
253 	va_end(ap);
254 	sh_exit(status);
255 }
256 
257 void
258 sh_verrx(int status, const char *fmt, va_list ap)
259 {
260 	exvwarning(-1, fmt, ap);
261 	sh_exit(status);
262 }
263 
264 void
265 sh_warn(const char *fmt, ...)
266 {
267 	va_list ap;
268 
269 	va_start(ap, fmt);
270 	exvwarning(errno, fmt, ap);
271 	va_end(ap);
272 }
273 
274 void
275 sh_vwarn(const char *fmt, va_list ap)
276 {
277 	exvwarning(errno, fmt, ap);
278 }
279 
280 void
281 sh_warnx(const char *fmt, ...)
282 {
283 	va_list ap;
284 
285 	va_start(ap, fmt);
286 	exvwarning(-1, fmt, ap);
287 	va_end(ap);
288 }
289 
290 void
291 sh_vwarnx(const char *fmt, va_list ap)
292 {
293 	exvwarning(-1, fmt, ap);
294 }
295 
296 
297 /*
298  * Table of error messages.
299  */
300 
301 struct errname {
302 	short errcode;		/* error number */
303 	short action;		/* operation which encountered the error */
304 	const char *msg;	/* text describing the error */
305 };
306 
307 
308 #define ALL (E_OPEN|E_CREAT|E_EXEC)
309 
310 STATIC const struct errname errormsg[] = {
311 	{ EINTR,	ALL,	"interrupted" },
312 	{ EACCES,	ALL,	"permission denied" },
313 	{ EIO,		ALL,	"I/O error" },
314 	{ EEXIST,	ALL,	"file exists" },
315 	{ ENOENT,	E_OPEN,	"no such file" },
316 	{ ENOENT,	E_CREAT,"directory nonexistent" },
317 	{ ENOENT,	E_EXEC,	"not found" },
318 	{ ENOTDIR,	E_OPEN,	"no such file" },
319 	{ ENOTDIR,	E_CREAT,"directory nonexistent" },
320 	{ ENOTDIR,	E_EXEC,	"not found" },
321 	{ EISDIR,	ALL,	"is a directory" },
322 #ifdef EMFILE
323 	{ EMFILE,	ALL,	"too many open files" },
324 #endif
325 	{ ENFILE,	ALL,	"file table overflow" },
326 	{ ENOSPC,	ALL,	"file system full" },
327 #ifdef EDQUOT
328 	{ EDQUOT,	ALL,	"disk quota exceeded" },
329 #endif
330 #ifdef ENOSR
331 	{ ENOSR,	ALL,	"no streams resources" },
332 #endif
333 	{ ENXIO,	ALL,	"no such device or address" },
334 	{ EROFS,	ALL,	"read-only file system" },
335 	{ ETXTBSY,	ALL,	"text busy" },
336 #ifdef EAGAIN
337 	{ EAGAIN,	E_EXEC,	"not enough memory" },
338 #endif
339 	{ ENOMEM,	ALL,	"not enough memory" },
340 #ifdef ENOLINK
341 	{ ENOLINK,	ALL,	"remote access failed" },
342 #endif
343 #ifdef EMULTIHOP
344 	{ EMULTIHOP,	ALL,	"remote access failed" },
345 #endif
346 #ifdef ECOMM
347 	{ ECOMM,	ALL,	"remote access failed" },
348 #endif
349 #ifdef ESTALE
350 	{ ESTALE,	ALL,	"remote access failed" },
351 #endif
352 #ifdef ETIMEDOUT
353 	{ ETIMEDOUT,	ALL,	"remote access failed" },
354 #endif
355 #ifdef ELOOP
356 	{ ELOOP,	ALL,	"symbolic link loop" },
357 #endif
358 #ifdef ENAMETOOLONG
359 	{ ENAMETOOLONG,	ALL,	"file name too long" },
360 #endif
361 	{ E2BIG,	E_EXEC,	"argument list too long" },
362 #ifdef ELIBACC
363 	{ ELIBACC,	E_EXEC,	"shared library missing" },
364 #endif
365 	{ 0,		0,	NULL },
366 };
367 
368 
369 /*
370  * Return a string describing an error.  The returned string may be a
371  * pointer to a static buffer that will be overwritten on the next call.
372  * Action describes the operation that got the error.
373  */
374 
375 const char *
376 errmsg(int e, int action)
377 {
378 	struct errname const *ep;
379 	static char buf[12];
380 
381 	for (ep = errormsg ; ep->errcode ; ep++) {
382 		if (ep->errcode == e && (ep->action & action) != 0)
383 			return ep->msg;
384 	}
385 	fmtstr(buf, sizeof buf, "error %d", e);
386 	return buf;
387 }
388