diff options
Diffstat (limited to 'eBones/krb/tf_shm.c')
| -rw-r--r-- | eBones/krb/tf_shm.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/eBones/krb/tf_shm.c b/eBones/krb/tf_shm.c new file mode 100644 index 0000000..5548f0d --- /dev/null +++ b/eBones/krb/tf_shm.c @@ -0,0 +1,174 @@ +/* + * Copyright 1988 by the Massachusetts Institute of Technology. + * For copying and distribution information, please see the file + * <Copyright.MIT>. + * + * Shared memory segment functions for session keys. Derived from code + * contributed by Dan Kolkowitz (kolk@jessica.stanford.edu). + * + * from: tf_shm.c,v 4.2 89/10/25 23:26:46 qjb Exp $ + * $Id: tf_shm.c,v 1.2 1994/07/19 19:26:26 g89r4222 Exp $ + */ + +#ifndef lint +static char rcsid[] = +"$Id: tf_shm.c,v 1.2 1994/07/19 19:26:26 g89r4222 Exp $"; +#endif lint + +#include <stdio.h> +#include <sys/types.h> +#include <sys/ipc.h> +#include <sys/shm.h> +#include <krb.h> +#include <des.h> +#include <sys/stat.h> +#include <fcntl.h> + +#define MAX_BUFF sizeof(des_cblock)*1000 /* room for 1k keys */ + +extern int errno; +extern int krb_debug; + +/* + * krb_create_shmtkt: + * + * create a shared memory segment for session keys, leaving its id + * in the specified filename. + */ + +int +krb_shm_create(file_name) +char *file_name; +{ + int retval; + int shmid; + struct shmid_ds shm_buf; + FILE *sfile; + uid_t me, metoo, getuid(), geteuid(); + + (void) krb_shm_dest(file_name); /* nuke it if it exists... + this cleans up to make sure we + don't slowly lose memory. */ + + shmid = shmget((long)IPC_PRIVATE,MAX_BUFF, IPC_CREAT); + if (shmid == -1) { + if (krb_debug) + perror("krb_shm_create shmget"); + return(KFAILURE); /* XXX */ + } + me = getuid(); + metoo = geteuid(); + /* + * now set up the buffer so that we can modify it + */ + shm_buf.shm_perm.uid = me; + shm_buf.shm_perm.gid = getgid(); + shm_buf.shm_perm.mode = 0600; + if (shmctl(shmid,IPC_SET,&shm_buf) < 0) { /*can now map it */ + if (krb_debug) + perror("krb_shm_create shmctl"); + (void) shmctl(shmid, IPC_RMID, 0); + return(KFAILURE); /* XXX */ + } + (void) shmctl(shmid, SHM_LOCK, 0); /* attempt to lock-in-core */ + /* arrange so the file is owned by the ruid + (swap real & effective uid if necessary). */ + if (me != metoo) { + if (setreuid(metoo, me) < 0) { + /* can't switch??? barf! */ + if (krb_debug) + perror("krb_shm_create: setreuid"); + (void) shmctl(shmid, IPC_RMID, 0); + return(KFAILURE); + } else + if (krb_debug) + printf("swapped UID's %d and %d\n",metoo,me); + } + if ((sfile = fopen(file_name,"w")) == 0) { + if (krb_debug) + perror("krb_shm_create file"); + (void) shmctl(shmid, IPC_RMID, 0); + return(KFAILURE); /* XXX */ + } + if (fchmod(fileno(sfile),0600) < 0) { + if (krb_debug) + perror("krb_shm_create fchmod"); + (void) shmctl(shmid, IPC_RMID, 0); + return(KFAILURE); /* XXX */ + } + if (me != metoo) { + if (setreuid(me, metoo) < 0) { + /* can't switch??? barf! */ + if (krb_debug) + perror("krb_shm_create: setreuid2"); + (void) shmctl(shmid, IPC_RMID, 0); + return(KFAILURE); + } else + if (krb_debug) + printf("swapped UID's %d and %d\n",me,metoo); + } + + (void) fprintf(sfile,"%d",shmid); + (void) fflush(sfile); + (void) fclose(sfile); + return(KSUCCESS); +} + + +/* + * krb_is_diskless: + * + * check / to see if file .diskless exists. If so it is diskless. + * Do it this way now to avoid dependencies on a particular routine. + * Choose root file system since that will be private to the client. + */ + +int krb_is_diskless() +{ + struct stat buf; + if (stat("/.diskless",&buf) < 0) + return(0); + else return(1); +} + +/* + * krb_shm_dest: destroy shared memory segment with session keys, and remove + * file pointing to it. + */ + +int krb_shm_dest(file) +char *file; +{ + int shmid; + FILE *sfile; + struct stat st_buf; + + if (stat(file,&st_buf) == 0) { + /* successful stat */ + if ((sfile = fopen(file,"r")) == 0) { + if (krb_debug) + perror("cannot open shared memory file"); + return(KFAILURE); /* XXX */ + } + if (fscanf(sfile,"%d",&shmid) == 1) { + if (shmctl(shmid,IPC_RMID,0) != 0) { + if (krb_debug) + perror("krb_shm_dest: cannot delete shm segment"); + (void) fclose(sfile); + return(KFAILURE); /* XXX */ + } + } else { + if (krb_debug) + fprintf(stderr, "bad format in shmid file\n"); + (void) fclose(sfile); + return(KFAILURE); /* XXX */ + } + (void) fclose(sfile); + (void) unlink(file); + return(KSUCCESS); + } else + return(RET_TKFIL); /* XXX */ +} + + + |
