From 498a87d196ac72cc446b7700c0953f2f9256e70f Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Wed, 20 Nov 2002 22:07:05 +0000 Subject: [PATCH] Rework usershell.c, as the old one was packed full of unhandled failures, returned stack allocated memory, and misbehaved itself in a number of other annoying ways, -Erik --- libc/unistd/usershell.c | 157 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 114 insertions(+), 43 deletions(-) diff --git a/libc/unistd/usershell.c b/libc/unistd/usershell.c index dcd95fb6d..13351de9f 100644 --- a/libc/unistd/usershell.c +++ b/libc/unistd/usershell.c @@ -1,63 +1,134 @@ -/* vi: set sw=4 ts=4: */ -/* getusershell and friends for uClibc +/* + * Copyright (c) 1985, 1993 + * The Regents of the University of California. All rights reserved. * - * Copyright (C) 2002 by Robert Griebl + * 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. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU Library General Public License as published by - * the Free Software Foundation; either version 2 of the License, or (at your - * option) any later version. + * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License - * for more details. - * - * You should have received a copy of the GNU Library General Public License - * along with this program; if not, write to the Free Software Foundation, - * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * This version has been hevily modified for use with uClibc + * November 2002, Erik Andersen */ +#include +#include +#include #include +#include +#include +#include #include +#include + +/* + * Local shells should NOT be added here. They should be added in + * /etc/shells. + */ -/* Rely on the .bss to zero these */ -static FILE *fp; -static int isopen; -static char **cursh; -static char *validsh [] = { "/bin/sh", "/bin/csh", 0 }; +static const char * const validsh[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; +static char **curshell, **shells, *strings; +static char **initshells __P((void)); -void endusershell ( void ) +/* + * Get a list of shells from _PATH_SHELLS, if it exists. + */ +char * getusershell(void) { - if ( fp && isopen ) - fclose ( fp ); - isopen = 0; + char *ret; + + if (curshell == NULL) + curshell = initshells(); + ret = *curshell; + if (ret != NULL) + curshell++; + return (ret); } -void setusershell ( void ) +static void __free_initshell_memory(void) { - if ( isopen ) - endusershell ( ); - fp = fopen ( "/etc/shells", "r" ); - cursh = validsh; - isopen = 1; + if (shells != NULL) { + free(shells); + } + shells = NULL; + if (strings != NULL) { + free(strings); + } + strings = NULL; } -char *getusershell ( void ) +void endusershell(void) { - char line [BUFSIZ]; - - if ( !isopen ) - setusershell ( ); + __free_initshell_memory(); + curshell = NULL; +} - if ( fp ) { - return fgets ( line, sizeof( line ) - 1, fp ); - } else { - char *result = *cursh; +void setusershell(void) +{ - if ( result ) - cursh++; - return result; - } + curshell = initshells(); } +static char ** initshells(void) +{ + register char **sp, *cp; + register FILE *fp; + struct stat statb; + int flen; + + __free_initshell_memory(); + + if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) + return (char **) validsh; + if (fstat(fileno(fp), &statb) == -1) { + goto cleanup; + } + if ((strings = malloc((unsigned)statb.st_size + 1)) == NULL) { + goto cleanup; + } + if ((shells = calloc((unsigned)statb.st_size / 3, sizeof (char *))) == NULL) { + goto cleanup; + } + /* No threads using this stream. */ + __fsetlocking (fp, FSETLOCKING_BYCALLER); + sp = shells; + cp = strings; + flen = statb.st_size; + while (fgets_unlocked(cp, flen - (cp - strings), fp) != NULL) { + while (*cp != '#' && *cp != '/' && *cp != '\0') + cp++; + if (*cp == '#' || *cp == '\0') + continue; + *sp++ = cp; + while (!isspace(*cp) && *cp != '#' && *cp != '\0') + cp++; + *cp++ = '\0'; + } + *sp = NULL; + fclose(fp); + return (shells); + +cleanup: + __free_initshell_memory(); + fclose(fp); + return (char **) validsh; +} -- 2.11.0