d79d4a7ced
- Get all functions prototyped or at least defined before use.
- Make code compile (Mostly) clean with -Wall set
- Start to reduce the degree to which DES aka libdes is built in.
- get all functions to the same uniform standard of definition:
int
foo(a, b)
int a;
int *b;
{
:
}
- fix numerous bugs exposed by above processes.
Note - this replaces the previous work which used an unpopular function
definition style.
177 lines
4.1 KiB
C
177 lines
4.1 KiB
C
/*
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* Copyright 1988 by the Massachusetts Institute of Technology.
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* For copying and distribution information, please see the file
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* <Copyright.MIT>.
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*
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* Shared memory segment functions for session keys. Derived from code
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* contributed by Dan Kolkowitz (kolk@jessica.stanford.edu).
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*
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* from: tf_shm.c,v 4.2 89/10/25 23:26:46 qjb Exp $
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* $Id: tf_shm.c,v 1.3 1995/07/18 16:39:48 mark Exp $
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*/
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#if 0
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#ifndef lint
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static char rcsid[] =
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"$Id: tf_shm.c,v 1.3 1995/07/18 16:39:48 mark Exp $";
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#endif lint
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#endif
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <krb.h>
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#include <des.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#define MAX_BUFF sizeof(des_cblock)*1000 /* room for 1k keys */
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extern int errno;
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extern int krb_debug;
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/*
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* krb_create_shmtkt:
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*
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* create a shared memory segment for session keys, leaving its id
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* in the specified filename.
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*/
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int
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krb_shm_create(file_name)
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char *file_name;
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{
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int retval;
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int shmid;
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struct shmid_ds shm_buf;
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FILE *sfile;
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uid_t me, metoo, getuid(), geteuid();
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(void) krb_shm_dest(file_name); /* nuke it if it exists...
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this cleans up to make sure we
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don't slowly lose memory. */
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shmid = shmget((long)IPC_PRIVATE,MAX_BUFF, IPC_CREAT);
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if (shmid == -1) {
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if (krb_debug)
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perror("krb_shm_create shmget");
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return(KFAILURE); /* XXX */
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}
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me = getuid();
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metoo = geteuid();
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/*
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* now set up the buffer so that we can modify it
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*/
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shm_buf.shm_perm.uid = me;
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shm_buf.shm_perm.gid = getgid();
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shm_buf.shm_perm.mode = 0600;
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if (shmctl(shmid,IPC_SET,&shm_buf) < 0) { /*can now map it */
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if (krb_debug)
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perror("krb_shm_create shmctl");
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(void) shmctl(shmid, IPC_RMID, 0);
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return(KFAILURE); /* XXX */
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}
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(void) shmctl(shmid, SHM_LOCK, 0); /* attempt to lock-in-core */
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/* arrange so the file is owned by the ruid
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(swap real & effective uid if necessary). */
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if (me != metoo) {
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if (setreuid(metoo, me) < 0) {
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/* can't switch??? barf! */
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if (krb_debug)
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perror("krb_shm_create: setreuid");
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(void) shmctl(shmid, IPC_RMID, 0);
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return(KFAILURE);
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} else
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if (krb_debug)
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printf("swapped UID's %d and %d\n",metoo,me);
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}
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if ((sfile = fopen(file_name,"w")) == 0) {
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if (krb_debug)
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perror("krb_shm_create file");
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(void) shmctl(shmid, IPC_RMID, 0);
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return(KFAILURE); /* XXX */
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}
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if (fchmod(fileno(sfile),0600) < 0) {
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if (krb_debug)
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perror("krb_shm_create fchmod");
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(void) shmctl(shmid, IPC_RMID, 0);
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return(KFAILURE); /* XXX */
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}
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if (me != metoo) {
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if (setreuid(me, metoo) < 0) {
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/* can't switch??? barf! */
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if (krb_debug)
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perror("krb_shm_create: setreuid2");
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(void) shmctl(shmid, IPC_RMID, 0);
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return(KFAILURE);
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} else
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if (krb_debug)
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printf("swapped UID's %d and %d\n",me,metoo);
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}
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(void) fprintf(sfile,"%d",shmid);
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(void) fflush(sfile);
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(void) fclose(sfile);
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return(KSUCCESS);
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}
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/*
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* krb_is_diskless:
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*
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* check / to see if file .diskless exists. If so it is diskless.
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* Do it this way now to avoid dependencies on a particular routine.
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* Choose root file system since that will be private to the client.
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*/
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int krb_is_diskless()
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{
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struct stat buf;
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if (stat("/.diskless",&buf) < 0)
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return(0);
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else return(1);
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}
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/*
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* krb_shm_dest: destroy shared memory segment with session keys, and remove
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* file pointing to it.
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*/
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int krb_shm_dest(file)
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char *file;
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{
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int shmid;
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FILE *sfile;
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struct stat st_buf;
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if (stat(file,&st_buf) == 0) {
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/* successful stat */
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if ((sfile = fopen(file,"r")) == 0) {
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if (krb_debug)
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perror("cannot open shared memory file");
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return(KFAILURE); /* XXX */
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}
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if (fscanf(sfile,"%d",&shmid) == 1) {
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if (shmctl(shmid,IPC_RMID,0) != 0) {
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if (krb_debug)
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perror("krb_shm_dest: cannot delete shm segment");
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(void) fclose(sfile);
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return(KFAILURE); /* XXX */
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}
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} else {
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if (krb_debug)
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fprintf(stderr, "bad format in shmid file\n");
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(void) fclose(sfile);
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return(KFAILURE); /* XXX */
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}
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(void) fclose(sfile);
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(void) unlink(file);
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return(KSUCCESS);
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} else
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return(RET_TKFIL); /* XXX */
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}
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