/*- * Copyright (c) 2002 Tim J. Robbins. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/lib/libc/gen/wordexp.c,v 1.6 2004/06/30 13:55:08 tjr Exp $ */ #include "namespace.h" #include #include #include #include #include #include #include #include #include #include "un-namespace.h" static int we_askshell(const char *, wordexp_t *, int); static int we_check(const char *, int); /* * wordexp -- * Perform shell word expansion on `words' and place the resulting list * of words in `we'. See wordexp(3). * * Specified by IEEE Std. 1003.1-2001. */ int wordexp(const char * __restrict words, wordexp_t * __restrict we, int flags) { int error; if (flags & WRDE_REUSE) wordfree(we); if ((flags & WRDE_APPEND) == 0) { we->we_wordc = 0; we->we_wordv = NULL; we->we_strings = NULL; we->we_nbytes = 0; } if ((error = we_check(words, flags)) != 0) { wordfree(we); return (error); } if ((error = we_askshell(words, we, flags)) != 0) { wordfree(we); return (error); } return (0); } /* * we_askshell -- * Use the `wordexp' /bin/sh builtin function to do most of the work * in expanding the word string. This function is complicated by * memory management. */ static int we_askshell(const char *words, wordexp_t *we, int flags) { int pdes[2]; /* Pipe to child */ char bbuf[9]; /* Buffer for byte count */ char wbuf[9]; /* Buffer for word count */ long nwords, nbytes; /* Number of words, bytes from child */ long i; /* Handy integer */ size_t sofs; /* Offset into we->we_strings */ size_t vofs; /* Offset into we->we_wordv */ pid_t pid; /* Process ID of child */ int status; /* Child exit status */ char *ifs; /* IFS env. var. */ char *np, *p; /* Handy pointers */ char *nstrings; /* Temporary for realloc() */ char **nwv; /* Temporary for realloc() */ if ((ifs = getenv("IFS")) == NULL) ifs = " \t\n"; if (pipe2(pdes, O_CLOEXEC) < 0) return (WRDE_NOSPACE); /* XXX */ if ((pid = fork()) < 0) { _close(pdes[0]); _close(pdes[1]); return (WRDE_NOSPACE); /* XXX */ } else if (pid == 0) { /* * We are the child; just get /bin/sh to run the wordexp * builtin on `words'. */ int devnull; char *cmd; _close(pdes[0]); _fcntl(pdes[1], F_SETFD, 0); if (_dup2(pdes[1], STDOUT_FILENO) < 0) _exit(1); _close(pdes[1]); if (asprintf(&cmd, "wordexp%c%s\n", *ifs, words) < 0) _exit(1); if ((flags & WRDE_SHOWERR) == 0) { if ((devnull = _open(_PATH_DEVNULL, O_RDWR, 0666)) < 0) _exit(1); if (_dup2(devnull, STDERR_FILENO) < 0) _exit(1); _close(devnull); } execl(_PATH_BSHELL, "sh", flags & WRDE_UNDEF ? "-u" : "+u", "-c", cmd, NULL); _exit(1); } /* * We are the parent; read the output of the shell wordexp function, * which is a 32-bit hexadecimal word count, a 32-bit hexadecimal * byte count (not including terminating null bytes), followed by * the expanded words separated by nulls. */ _close(pdes[1]); if (_read(pdes[0], wbuf, 8) != 8 || _read(pdes[0], bbuf, 8) != 8) { _close(pdes[0]); _waitpid(pid, &status, 0); return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX); } wbuf[8] = bbuf[8] = '\0'; nwords = strtol(wbuf, NULL, 16); nbytes = strtol(bbuf, NULL, 16) + nwords; /* * Allocate or reallocate (when flags & WRDE_APPEND) the word vector * and string storage buffers for the expanded words we're about to * read from the child. */ sofs = we->we_nbytes; vofs = we->we_wordc; if ((flags & (WRDE_DOOFFS|WRDE_APPEND)) == (WRDE_DOOFFS|WRDE_APPEND)) vofs += we->we_offs; we->we_wordc += nwords; we->we_nbytes += nbytes; if ((nwv = realloc(we->we_wordv, (we->we_wordc + 1 + (flags & WRDE_DOOFFS ? we->we_offs : 0)) * sizeof(char *))) == NULL) { _close(pdes[0]); _waitpid(pid, &status, 0); return (WRDE_NOSPACE); } we->we_wordv = nwv; if ((nstrings = realloc(we->we_strings, we->we_nbytes)) == NULL) { _close(pdes[0]); _waitpid(pid, &status, 0); return (WRDE_NOSPACE); } for (i = 0; i < vofs; i++) if (we->we_wordv[i] != NULL) we->we_wordv[i] += nstrings - we->we_strings; we->we_strings = nstrings; if (_read(pdes[0], we->we_strings + sofs, nbytes) != nbytes) { _close(pdes[0]); _waitpid(pid, &status, 0); return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX); } if (_waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { _close(pdes[0]); return (flags & WRDE_UNDEF ? WRDE_BADVAL : WRDE_SYNTAX); } _close(pdes[0]); /* * Break the null-terminated expanded word strings out into * the vector. */ if (vofs == 0 && flags & WRDE_DOOFFS) while (vofs < we->we_offs) we->we_wordv[vofs++] = NULL; p = we->we_strings + sofs; while (nwords-- != 0) { we->we_wordv[vofs++] = p; if ((np = memchr(p, '\0', nbytes)) == NULL) return (WRDE_NOSPACE); /* XXX */ nbytes -= np - p + 1; p = np + 1; } we->we_wordv[vofs] = NULL; return (0); } /* * we_check -- * Check that the string contains none of the following unquoted * special characters: |&;<>(){} * or command substitutions when WRDE_NOCMD is set in flags. */ static int we_check(const char *words, int flags) { char c; int dquote, level, quote, squote; quote = squote = dquote = 0; while ((c = *words++) != '\0') { switch (c) { case '\\': quote ^= 1; continue; case '\'': if (quote + dquote == 0) squote ^= 1; break; case '"': if (quote + squote == 0) dquote ^= 1; break; case '`': if (quote + squote == 0 && flags & WRDE_NOCMD) return (WRDE_CMDSUB); while ((c = *words++) != '\0' && c != '`') if (c == '\\' && (c = *words++) == '\0') break; if (c == '\0') return (WRDE_SYNTAX); break; case '|': case '&': case ';': case '<': case '>': case '{': case '}': case '(': case ')': case '\n': if (quote + squote + dquote == 0) return (WRDE_BADCHAR); break; case '$': if ((c = *words++) == '\0') break; else if (quote + squote == 0 && c == '(') { if (flags & WRDE_NOCMD && *words != '(') return (WRDE_CMDSUB); level = 1; while ((c = *words++) != '\0') { if (c == '\\') { if ((c = *words++) == '\0') break; } else if (c == '(') level++; else if (c == ')' && --level == 0) break; } if (c == '\0' || level != 0) return (WRDE_SYNTAX); } else if (quote + squote == 0 && c == '{') { level = 1; while ((c = *words++) != '\0') { if (c == '\\') { if ((c = *words++) == '\0') break; } else if (c == '{') level++; else if (c == '}' && --level == 0) break; } if (c == '\0' || level != 0) return (WRDE_SYNTAX); } else c = *--words; break; default: break; } quote = 0; } if (quote + squote + dquote != 0) return (WRDE_SYNTAX); return (0); } /* * wordfree -- * Free the result of wordexp(). See wordexp(3). * * Specified by IEEE Std. 1003.1-2001. */ void wordfree(wordexp_t *we) { if (we == NULL) return; free(we->we_wordv); free(we->we_strings); we->we_wordv = NULL; we->we_strings = NULL; we->we_nbytes = 0; we->we_wordc = 0; }