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/*
* lib/krb5/rcache/rc_dfl.c
*
* This file of the Kerberos V5 software is derived from public-domain code
* contributed by Daniel J. Bernstein, <brnstnd@acf10.nyu.edu>.
*
*/
/*
* An implementation for the default replay cache type.
*/
#define FREE(x) ((void) free((char *) (x)))
#include "rc_base.h"
#include "rc_dfl.h"
#include "rc_io.h"
#include <k5-int.h>
/*
* If NOIOSTUFF is defined at compile time, dfl rcaches will be per-process.
*/
/*
Local stuff:
static int hash(krb5_donot_replay *rep, int hsize)
returns hash value of *rep, between 0 and hsize - 1
HASHSIZE
size of hash table (constant), can be preset
static int cmp(krb5_donot_replay *old, krb5_donot_replay *new, krb5_deltat t)
compare old and new; return CMP_REPLAY or CMP_HOHUM
static int alive(krb5_context, krb5_donot_replay *new, krb5_deltat t)
see if new is still alive; return CMP_EXPIRED or CMP_HOHUM
CMP_MALLOC, CMP_EXPIRED, CMP_REPLAY, CMP_HOHUM
return codes from cmp(), alive(), and store()
struct dfl_data
data stored in this cache type, namely "dfl"
struct authlist
multilinked list of reps
static int rc_store(context, krb5_rcache id, krb5_donot_replay *rep)
store rep in cache id; return CMP_REPLAY if replay, else CMP_MALLOC/CMP_HOHUM
*/
#ifndef HASHSIZE
#define HASHSIZE 997 /* a convenient prime */
#endif
#ifndef EXCESSREPS
#define EXCESSREPS 30
#endif
/*
* The rcache will be automatically expunged when the number of
* expired krb5_donot_replays encountered incidentally in searching
* exceeds the number of live krb5_donot_replays by EXCESSREPS. With
* the defaults here, a typical cache might build up some 10K of
* expired krb5_donot_replays before an automatic expunge, with the
* waste basically independent of the number of stores per minute.
*
* The rcache will also automatically be expunged when it encounters
* more than EXCESSREPS expired entries when recovering a cache in
* dfl_recover.
*/
static int
hash(krb5_donot_replay *rep, int hsize)
{
return (int) ((((rep->cusec + rep->ctime + *rep->server + *rep->client)
% hsize) + hsize) % hsize);
/* We take this opportunity to once again complain about C's idiotic %. */
}
#define CMP_MALLOC -3
#define CMP_EXPIRED -2
#define CMP_REPLAY -1
#define CMP_HOHUM 0
/*ARGSUSED*/
static int
cmp(krb5_donot_replay *old, krb5_donot_replay *new, krb5_deltat t)
{
if ((old->cusec == new->cusec) && /* most likely to distinguish */
(old->ctime == new->ctime) &&
(strcmp(old->client, new->client) == 0) &&
(strcmp(old->server, new->server) == 0)) /* always true */
return CMP_REPLAY;
return CMP_HOHUM;
}
static int
alive(krb5_context context, krb5_donot_replay *new, krb5_deltat t)
{
krb5_int32 mytime;
if (krb5_timeofday(context, &mytime))
return CMP_HOHUM; /* who cares? */
/* I hope we don't have to worry about overflow */
if (new->ctime + t < mytime)
return CMP_EXPIRED;
return CMP_HOHUM;
}
struct dfl_data
{
char *name;
krb5_deltat lifespan;
int hsize;
int numhits;
int nummisses;
struct authlist **h;
struct authlist *a;
#ifndef NOIOSTUFF
krb5_rc_iostuff d;
#endif
char recovering;
};
struct authlist
{
krb5_donot_replay rep;
struct authlist *na;
struct authlist *nh;
};
/* of course, list is backwards from file */
/* hash could be forwards since we have to search on match, but naaaah */
static int
rc_store(krb5_context context, krb5_rcache id, krb5_donot_replay *rep)
{
struct dfl_data *t = (struct dfl_data *)id->data;
int rephash;
struct authlist *ta;
rephash = hash(rep, t->hsize);
for (ta = t->h[rephash]; ta; ta = ta->nh) {
switch(cmp(&ta->rep, rep, t->lifespan))
{
case CMP_REPLAY:
return CMP_REPLAY;
case CMP_HOHUM:
if (alive(context, &ta->rep, t->lifespan) == CMP_EXPIRED)
t->nummisses++;
else
t->numhits++;
break;
default:
; /* wtf? */
}
}
if (!(ta = (struct authlist *) malloc(sizeof(struct authlist))))
return CMP_MALLOC;
ta->na = t->a; t->a = ta;
ta->nh = t->h[rephash]; t->h[rephash] = ta;
ta->rep = *rep;
if (!(ta->rep.client = strdup(rep->client))) {
FREE(ta);
return CMP_MALLOC;
}
if (!(ta->rep.server = strdup(rep->server))) {
FREE(ta->rep.client);
FREE(ta);
return CMP_MALLOC;
}
return CMP_HOHUM;
}
char * KRB5_CALLCONV
krb5_rc_dfl_get_name(krb5_context context, krb5_rcache id)
{
return ((struct dfl_data *) (id->data))->name;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_get_span(krb5_context context, krb5_rcache id,
krb5_deltat *lifespan)
{
*lifespan = ((struct dfl_data *) (id->data))->lifespan;
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_init(krb5_context context, krb5_rcache id, krb5_deltat lifespan)
{
struct dfl_data *t = (struct dfl_data *)id->data;
krb5_error_code retval;
t->lifespan = lifespan ? lifespan : context->clockskew;
/* default to clockskew from the context */
#ifndef NOIOSTUFF
if ((retval = krb5_rc_io_creat(context, &t->d, &t->name)))
return retval;
if ((krb5_rc_io_write(context, &t->d,
(krb5_pointer) &t->lifespan, sizeof(t->lifespan))
|| krb5_rc_io_sync(context, &t->d)))
return KRB5_RC_IO;
#endif
return 0;
}
krb5_error_code
krb5_rc_dfl_close_no_free(krb5_context context, krb5_rcache id)
{
struct dfl_data *t = (struct dfl_data *)id->data;
struct authlist *q;
FREE(t->h);
if (t->name)
FREE(t->name);
while ((q = t->a))
{
t->a = q->na;
FREE(q->rep.client);
FREE(q->rep.server);
FREE(q);
}
#ifndef NOIOSTUFF
if (t->d.fd >= 0)
(void) krb5_rc_io_close(context, &t->d);
#endif
FREE(t);
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_close(krb5_context context, krb5_rcache id)
{
krb5_rc_dfl_close_no_free(context, id);
free(id);
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_destroy(krb5_context context, krb5_rcache id)
{
#ifndef NOIOSTUFF
if (krb5_rc_io_destroy(context, &((struct dfl_data *) (id->data))->d))
return KRB5_RC_IO;
#endif
return krb5_rc_dfl_close(context, id);
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_resolve(krb5_context context, krb5_rcache id, char *name)
{
struct dfl_data *t = 0;
krb5_error_code retval;
/* allocate id? no */
if (!(t = (struct dfl_data *) malloc(sizeof(struct dfl_data))))
return KRB5_RC_MALLOC;
id->data = (krb5_pointer) t;
memset(t, 0, sizeof(struct dfl_data));
if (name) {
t->name = malloc(strlen(name)+1);
if (!t->name) {
retval = KRB5_RC_MALLOC;
goto cleanup;
}
strcpy(t->name, name);
} else
t->name = 0;
t->numhits = t->nummisses = 0;
t->hsize = HASHSIZE; /* no need to store---it's memory-only */
t->h = (struct authlist **) malloc(t->hsize*sizeof(struct authlist *));
if (!t->h) {
retval = KRB5_RC_MALLOC;
goto cleanup;
}
memset(t->h, 0, t->hsize*sizeof(struct authlist *));
t->a = (struct authlist *) 0;
#ifndef NOIOSTUFF
t->d.fd = -1;
#endif
t->recovering = 0;
return 0;
cleanup:
if (t) {
if (t->name)
krb5_xfree(t->name);
if (t->h)
krb5_xfree(t->h);
krb5_xfree(t);
}
return retval;
}
void
krb5_rc_free_entry(krb5_context context, krb5_donot_replay **rep)
{
krb5_donot_replay *rp = *rep;
*rep = NULL;
if (rp)
{
if (rp->client)
free(rp->client);
if (rp->server)
free(rp->server);
rp->client = NULL;
rp->server = NULL;
free(rp);
}
}
static krb5_error_code
krb5_rc_io_fetch(krb5_context context, struct dfl_data *t,
krb5_donot_replay *rep, int maxlen)
{
int len;
krb5_error_code retval;
rep->client = rep->server = 0;
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) &len, sizeof(len));
if (retval)
return retval;
if ((len <= 0) || (len >= maxlen))
return KRB5_RC_IO_EOF;
rep->client = malloc (len);
if (!rep->client)
return KRB5_RC_MALLOC;
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) rep->client, len);
if (retval)
goto errout;
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) &len, sizeof(len));
if (retval)
goto errout;
if ((len <= 0) || (len >= maxlen)) {
retval = KRB5_RC_IO_EOF;
goto errout;
}
rep->server = malloc (len);
if (!rep->server) {
retval = KRB5_RC_MALLOC;
goto errout;
}
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) rep->server, len);
if (retval)
goto errout;
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) &rep->cusec,
sizeof(rep->cusec));
if (retval)
goto errout;
retval = krb5_rc_io_read(context, &t->d, (krb5_pointer) &rep->ctime,
sizeof(rep->ctime));
if (retval)
goto errout;
return 0;
errout:
if (rep->client)
krb5_xfree(rep->client);
if (rep->server)
krb5_xfree(rep->server);
rep->client = rep->server = 0;
return retval;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_recover(krb5_context context, krb5_rcache id)
{
#ifdef NOIOSTUFF
return KRB5_RC_NOIO;
#else
struct dfl_data *t = (struct dfl_data *)id->data;
krb5_donot_replay *rep = 0;
krb5_error_code retval;
long max_size;
int expired_entries = 0;
if ((retval = krb5_rc_io_open(context, &t->d, t->name)))
return retval;
t->recovering = 1;
max_size = krb5_rc_io_size(context, &t->d);
rep = NULL;
if (krb5_rc_io_read(context, &t->d, (krb5_pointer) &t->lifespan,
sizeof(t->lifespan))) {
retval = KRB5_RC_IO;
goto io_fail;
}
if (!(rep = (krb5_donot_replay *) malloc(sizeof(krb5_donot_replay)))) {
retval = KRB5_RC_MALLOC;
goto io_fail;
}
rep->client = NULL;
rep->server = NULL;
/* now read in each auth_replay and insert into table */
for (;;) {
if (krb5_rc_io_mark(context, &t->d)) {
retval = KRB5_RC_IO;
goto io_fail;
}
retval = krb5_rc_io_fetch(context, t, rep, (int) max_size);
if (retval == KRB5_RC_IO_EOF)
break;
else if (retval != 0)
goto io_fail;
if (alive(context, rep, t->lifespan) != CMP_EXPIRED) {
if (rc_store(context, id, rep) == CMP_MALLOC) {
retval = KRB5_RC_MALLOC; goto io_fail;
}
} else {
expired_entries++;
}
/*
* free fields allocated by rc_io_fetch
*/
FREE(rep->server);
FREE(rep->client);
rep->server = 0;
rep->client = 0;
}
retval = 0;
krb5_rc_io_unmark(context, &t->d);
/*
* An automatic expunge here could remove the need for
* mark/unmark but that would be inefficient.
*/
io_fail:
krb5_rc_free_entry(context, &rep);
if (retval)
krb5_rc_io_close(context, &t->d);
else if (expired_entries > EXCESSREPS)
retval = krb5_rc_dfl_expunge(context, id);
t->recovering = 0;
return retval;
#endif
}
static krb5_error_code
krb5_rc_io_store(krb5_context context, struct dfl_data *t,
krb5_donot_replay *rep)
{
unsigned int clientlen, serverlen, len;
char *buf, *ptr;
krb5_error_code ret;
clientlen = strlen(rep->client) + 1;
serverlen = strlen(rep->server) + 1;
len = sizeof(clientlen) + clientlen + sizeof(serverlen) + serverlen +
sizeof(rep->cusec) + sizeof(rep->ctime);
buf = malloc(len);
if (buf == 0)
return KRB5_RC_MALLOC;
ptr = buf;
memcpy(ptr, &clientlen, sizeof(clientlen)); ptr += sizeof(clientlen);
memcpy(ptr, rep->client, clientlen); ptr += clientlen;
memcpy(ptr, &serverlen, sizeof(serverlen)); ptr += sizeof(serverlen);
memcpy(ptr, rep->server, serverlen); ptr += serverlen;
memcpy(ptr, &rep->cusec, sizeof(rep->cusec)); ptr += sizeof(rep->cusec);
memcpy(ptr, &rep->ctime, sizeof(rep->ctime)); ptr += sizeof(rep->ctime);
ret = krb5_rc_io_write(context, &t->d, buf, len);
free(buf);
return ret;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_store(krb5_context context, krb5_rcache id, krb5_donot_replay *rep)
{
krb5_error_code ret;
struct dfl_data *t = (struct dfl_data *)id->data;
switch(rc_store(context, id, rep)) {
case CMP_MALLOC:
return KRB5_RC_MALLOC;
case CMP_REPLAY:
return KRB5KRB_AP_ERR_REPEAT;
case 0: break;
default: /* wtf? */ ;
}
#ifndef NOIOSTUFF
ret = krb5_rc_io_store(context, t, rep);
if (ret)
return ret;
#endif
/* Shall we automatically expunge? */
if (t->nummisses > t->numhits + EXCESSREPS)
{
return krb5_rc_dfl_expunge(context, id);
}
#ifndef NOIOSTUFF
else
{
if (krb5_rc_io_sync(context, &t->d))
return KRB5_RC_IO;
}
#endif
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_rc_dfl_expunge(krb5_context context, krb5_rcache id)
{
struct dfl_data *t = (struct dfl_data *)id->data;
#ifdef NOIOSTUFF
int i;
struct authlist **q;
struct authlist **qt;
struct authlist *r;
struct authlist *rt;
for (q = &t->a; *q; q = qt) {
qt = &(*q)->na;
if (alive(context, &(*q)->rep, t->lifespan) == CMP_EXPIRED) {
FREE((*q)->rep.client);
FREE((*q)->rep.server);
FREE(*q);
*q = *qt; /* why doesn't this feel right? */
}
}
for (i = 0; i < t->hsize; i++)
t->h[i] = (struct authlist *) 0;
for (r = t->a; r; r = r->na) {
i = hash(&r->rep, t->hsize);
rt = t->h[i];
t->h[i] = r;
r->nh = rt;
}
#else
struct authlist *q;
char *name;
krb5_error_code retval;
krb5_rcache tmp;
krb5_deltat lifespan = t->lifespan; /* save original lifespan */
if (! t->recovering) {
name = t->name;
t->name = 0; /* Clear name so it isn't freed */
(void) krb5_rc_dfl_close_no_free(context, id);
retval = krb5_rc_dfl_resolve(context, id, name);
free(name);
if (retval)
return retval;
retval = krb5_rc_dfl_recover(context, id);
if (retval)
return retval;
t = (struct dfl_data *)id->data; /* point to recovered cache */
}
tmp = (krb5_rcache) malloc(sizeof(*tmp));
if (!tmp)
return ENOMEM;
retval = krb5_rc_resolve_type(context, &tmp, "dfl");
if (retval)
return retval;
retval = krb5_rc_resolve(context, tmp, 0);
if (retval)
return retval;
retval = krb5_rc_initialize(context, tmp, lifespan);
if (retval)
return retval;
for (q = t->a; q; q = q->na) {
if (krb5_rc_io_store(context, (struct dfl_data *)tmp->data, &q->rep))
return KRB5_RC_IO;
}
if (krb5_rc_io_sync(context, &t->d))
return KRB5_RC_IO;
if (krb5_rc_io_move(context, &t->d, &((struct dfl_data *)tmp->data)->d))
return KRB5_RC_IO;
(void) krb5_rc_dfl_close(context, tmp);
#endif
return 0;
}
|