/* * perm.c - check user permission for at(1) * Copyright (C) 1994 Thomas Koenig * * 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. The name of the author(s) may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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(S) 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, WETHER 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. */ #ifndef lint static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ /* System Headers */ #include <sys/types.h> #include <err.h> #include <errno.h> #include <pwd.h> #include <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> /* Local headers */ #include "privs.h" #include "at.h" /* Macros */ #define MAXUSERID 10 /* Structures and unions */ /* Function declarations */ static int check_for_user(FILE *fp,const char *name); /* Local functions */ static int check_for_user(FILE *fp,const char *name) { char *buffer; size_t len; int found = 0; len = strlen(name); if ((buffer = malloc(len+2)) == NULL) errx(EXIT_FAILURE, "virtual memory exhausted"); while(fgets(buffer, len+2, fp) != NULL) { if ((strncmp(name, buffer, len) == 0) && (buffer[len] == '\n')) { found = 1; break; } } fclose(fp); free(buffer); return found; } /* Global functions */ int check_permission() { FILE *fp; uid_t uid = geteuid(); struct passwd *pentry; if (uid==0) return 1; if ((pentry = getpwuid(uid)) == NULL) err(EXIT_FAILURE, "cannot access user database"); PRIV_START fp=fopen(PERM_PATH "at.allow","r"); PRIV_END if (fp != NULL) { return check_for_user(fp, pentry->pw_name); } else if (errno == ENOENT) { PRIV_START fp=fopen(PERM_PATH "at.deny", "r"); PRIV_END if (fp != NULL) { return !check_for_user(fp, pentry->pw_name); } else if (errno != ENOENT) warn("at.deny"); } else warn("at.allow"); return 0; }