2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2002 Tim J. Robbins.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include "namespace.h"
30 #include <sys/cdefs.h>
31 #include <sys/types.h>
43 #include "un-namespace.h"
44 #include "libc_private.h"
46 __FBSDID("$FreeBSD$");
48 static int we_askshell(const char *, wordexp_t *, int);
49 static int we_check(const char *);
53 * Perform shell word expansion on `words' and place the resulting list
54 * of words in `we'. See wordexp(3).
56 * Specified by IEEE Std. 1003.1-2001.
59 wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags)
63 if (flags & WRDE_REUSE)
65 if ((flags & WRDE_APPEND) == 0) {
68 we->we_strings = NULL;
71 if ((error = we_check(words)) != 0) {
75 if ((error = we_askshell(words, we, flags)) != 0) {
83 we_read_fully(int fd, char *buffer, size_t len)
90 nread = _read(fd, buffer + done, len - done);
91 if (nread == -1 && errno == EINTR)
96 } while (done != len);
101 we_write_fully(int fd, const char *buffer, size_t len)
108 nwritten = _write(fd, buffer + done, len - done);
109 if (nwritten == -1 && errno == EINTR)
114 } while (done != len);
120 * Use the `freebsd_wordexp' /bin/sh builtin function to do most of the
121 * work in expanding the word string. This function is complicated by
125 we_askshell(const char *words, wordexp_t *we, int flags)
127 int pdesw[2]; /* Pipe for writing words */
128 int pdes[2]; /* Pipe for reading output */
129 char wfdstr[sizeof(int) * 3 + 1];
130 char buf[35]; /* Buffer for byte and word count */
131 long nwords, nbytes; /* Number of words, bytes from child */
132 long i; /* Handy integer */
133 size_t sofs; /* Offset into we->we_strings */
134 size_t vofs; /* Offset into we->we_wordv */
135 pid_t pid; /* Process ID of child */
136 pid_t wpid; /* waitpid return value */
137 int status; /* Child exit status */
138 int error; /* Our return value */
139 int serrno; /* errno to return */
140 char *np, *p; /* Handy pointers */
141 char *nstrings; /* Temporary for realloc() */
142 char **nwv; /* Temporary for realloc() */
143 sigset_t newsigblock, oldsigblock;
149 if (pipe2(pdesw, O_CLOEXEC) < 0)
150 return (WRDE_NOSPACE); /* XXX */
151 snprintf(wfdstr, sizeof(wfdstr), "%d", pdesw[0]);
152 if (pipe2(pdes, O_CLOEXEC) < 0) {
155 return (WRDE_NOSPACE); /* XXX */
157 (void)sigemptyset(&newsigblock);
158 (void)sigaddset(&newsigblock, SIGCHLD);
159 (void)__libc_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock);
160 if ((pid = fork()) < 0) {
166 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
168 return (WRDE_NOSPACE); /* XXX */
172 * We are the child; make /bin/sh expand `words'.
174 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
175 if ((pdes[1] != STDOUT_FILENO ?
176 _dup2(pdes[1], STDOUT_FILENO) :
177 _fcntl(pdes[1], F_SETFD, 0)) < 0)
179 if (_fcntl(pdesw[0], F_SETFD, 0) < 0)
181 execl(_PATH_BSHELL, "sh", flags & WRDE_UNDEF ? "-u" : "+u",
182 "-c", "IFS=$1;eval \"$2\";"
183 "freebsd_wordexp -f \"$3\" ${4:+\"$4\"}",
185 ifs != NULL ? ifs : " \t\n",
186 flags & WRDE_SHOWERR ? "" : "exec 2>/dev/null",
188 flags & WRDE_NOCMD ? "-p" : "",
194 * We are the parent; write the words.
198 if (!we_write_fully(pdesw[1], words, strlen(words))) {
205 * Read the output of the shell wordexp function,
206 * which is a byte indicating that the words were parsed successfully,
207 * a 64-bit hexadecimal word count, a dummy byte, a 64-bit hexadecimal
208 * byte count (not including terminating null bytes), followed by the
209 * expanded words separated by nulls.
211 switch (we_read_fully(pdes[0], buf, 34)) {
213 error = buf[0] == 'C' ? WRDE_CMDSUB : WRDE_BADVAL;
224 nwords = strtol(buf + 1, NULL, 16);
226 nbytes = strtol(buf + 18, NULL, 16) + nwords;
229 * Allocate or reallocate (when flags & WRDE_APPEND) the word vector
230 * and string storage buffers for the expanded words we're about to
231 * read from the child.
233 sofs = we->we_nbytes;
235 if ((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS|WRDE_APPEND))
237 we->we_wordc += nwords;
238 we->we_nbytes += nbytes;
239 if ((nwv = reallocarray(we->we_wordv, (we->we_wordc + 1 +
240 (flags & WRDE_DOOFFS ? we->we_offs : 0)),
241 sizeof(char *))) == NULL) {
242 error = WRDE_NOSPACE;
246 if ((nstrings = realloc(we->we_strings, we->we_nbytes)) == NULL) {
247 error = WRDE_NOSPACE;
250 for (i = 0; i < vofs; i++)
251 if (we->we_wordv[i] != NULL)
252 we->we_wordv[i] += nstrings - we->we_strings;
253 we->we_strings = nstrings;
255 if (we_read_fully(pdes[0], we->we_strings + sofs, nbytes) != nbytes) {
256 error = WRDE_NOSPACE; /* abort for unknown reason */
265 wpid = _waitpid(pid, &status, 0);
266 while (wpid < 0 && errno == EINTR);
267 (void)__libc_sigprocmask(SIG_SETMASK, &oldsigblock, NULL);
272 if (wpid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0)
273 return (WRDE_NOSPACE); /* abort for unknown reason */
276 * Break the null-terminated expanded word strings out into
279 if (vofs == 0 && flags & WRDE_DOOFFS)
280 while (vofs < we->we_offs)
281 we->we_wordv[vofs++] = NULL;
282 p = we->we_strings + sofs;
283 while (nwords-- != 0) {
284 we->we_wordv[vofs++] = p;
285 if ((np = memchr(p, '\0', nbytes)) == NULL)
286 return (WRDE_NOSPACE); /* XXX */
287 nbytes -= np - p + 1;
290 we->we_wordv[vofs] = NULL;
297 * Check that the string contains none of the following unquoted
298 * special characters: <newline> |&;<>(){}
299 * This mainly serves for {} which are normally legal in sh.
300 * It deliberately does not attempt to model full sh syntax.
303 we_check(const char *words)
306 /* Saw \ or $, possibly not special: */
307 bool quote = false, dollar = false;
308 /* Saw ', ", ${, ` or $(, possibly not special: */
309 bool have_sq = false, have_dq = false, have_par_begin = false;
310 bool have_cmd = false;
311 /* Definitely saw a ', ", ${, ` or $(, need a closing character: */
312 bool need_sq = false, need_dq = false, need_par_end = false;
313 bool need_cmd_old = false, need_cmd_new = false;
315 while ((c = *words++) != '\0') {
327 if (!quote && !have_sq && !have_dq)
334 if (!quote && !have_sq && !have_dq)
341 if (!quote && !have_sq && !have_cmd)
344 need_cmd_old = false;
348 if (!quote && !dollar && !have_sq && !have_dq &&
350 return (WRDE_BADCHAR);
352 if (!quote && !have_sq)
354 have_par_begin = true;
358 if (!quote && !have_sq && !have_dq && !have_par_begin &&
360 return (WRDE_BADCHAR);
361 need_par_end = false;
364 if (!quote && !dollar && !have_sq && !have_dq &&
366 return (WRDE_BADCHAR);
368 if (!quote && !have_sq)
374 if (!quote && !have_sq && !have_dq && !have_cmd)
375 return (WRDE_BADCHAR);
376 need_cmd_new = false;
378 case '|': case '&': case ';': case '<': case '>': case '\n':
379 if (!quote && !have_sq && !have_dq && !have_cmd)
380 return (WRDE_BADCHAR);
385 quote = dollar = false;
387 if (quote || dollar || need_sq || need_dq || need_par_end ||
388 need_cmd_old || need_cmd_new)
389 return (WRDE_SYNTAX);
396 * Free the result of wordexp(). See wordexp(3).
398 * Specified by IEEE Std. 1003.1-2001.
401 wordfree(wordexp_t *we)
407 free(we->we_strings);
409 we->we_strings = NULL;