/* $OpenBSD: getusershell.c,v 1.9 2012/04/06 20:54:41 deraadt Exp $ */ /* * Copyright (c) 1985, 1993 * The Regents of the University of California. 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. * 3. 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 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. */ #include #include #include #include #include #include #include #include /* * Local shells should NOT be added here. They should be added in * /etc/shells. */ static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, _PATH_KSHELL, NULL }; static char **curshell, **shells, *strings; static char **initshells(void); /* * Get a list of shells from _PATH_SHELLS, if it exists. */ char * getusershell(void) { char *ret; if (curshell == NULL) curshell = initshells(); ret = *curshell; if (ret != NULL) curshell++; return (ret); } void endusershell(void) { if (shells != NULL) free(shells); shells = NULL; if (strings != NULL) free(strings); strings = NULL; curshell = NULL; } void setusershell(void) { curshell = initshells(); } static char ** initshells(void) { char **sp, *cp; FILE *fp; struct stat statb; if (shells != NULL) free(shells); shells = NULL; if (strings != NULL) free(strings); strings = NULL; if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) return (okshells); if (fstat(fileno(fp), &statb) == -1) { (void)fclose(fp); return (okshells); } if (statb.st_size > SIZE_T_MAX) { (void)fclose(fp); return (okshells); } if ((strings = malloc((size_t)statb.st_size)) == NULL) { (void)fclose(fp); return (okshells); } shells = calloc((size_t)(statb.st_size / 3), sizeof (char *)); if (shells == NULL) { (void)fclose(fp); free(strings); strings = NULL; return (okshells); } sp = shells; cp = strings; while (fgets(cp, MAXPATHLEN + 1, 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; (void)fclose(fp); return (shells); }