126 lines
2.8 KiB
C
126 lines
2.8 KiB
C
/*-
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* perm.c - check user permission for at(1)
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (C) 1994 Thomas Koenig
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. The name of the author(s) may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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/* System Headers */
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#include <sys/types.h>
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#include <err.h>
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#include <errno.h>
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#include <pwd.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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/* Local headers */
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#include "at.h"
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#include "perm.h"
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#include "privs.h"
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/* Macros */
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#define MAXUSERID 10
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/* Structures and unions */
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/* Function declarations */
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static int check_for_user(FILE *fp,const char *name);
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/* Local functions */
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static int check_for_user(FILE *fp,const char *name)
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{
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char *buffer;
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size_t len;
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int found = 0;
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len = strlen(name);
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if ((buffer = malloc(len+2)) == NULL)
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errx(EXIT_FAILURE, "virtual memory exhausted");
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while(fgets(buffer, len+2, fp) != NULL)
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{
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if ((strncmp(name, buffer, len) == 0) &&
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(buffer[len] == '\n'))
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{
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found = 1;
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break;
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}
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}
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fclose(fp);
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free(buffer);
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return found;
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}
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/* Global functions */
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int check_permission(void)
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{
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FILE *fp;
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uid_t uid = geteuid();
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struct passwd *pentry;
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if (uid==0)
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return 1;
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if ((pentry = getpwuid(uid)) == NULL)
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err(EXIT_FAILURE, "cannot access user database");
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PRIV_START
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fp=fopen(PERM_PATH "at.allow","r");
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PRIV_END
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if (fp != NULL)
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{
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return check_for_user(fp, pentry->pw_name);
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}
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else if (errno == ENOENT)
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{
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PRIV_START
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fp=fopen(PERM_PATH "at.deny", "r");
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PRIV_END
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if (fp != NULL)
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{
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return !check_for_user(fp, pentry->pw_name);
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}
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else if (errno != ENOENT)
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warn("at.deny");
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}
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else
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warn("at.allow");
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return 0;
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}
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