[PATCH] knfsd: svcrpc: gss: server-side implementation of rpcsec_gss privacy

Server-side implementation of rpcsec_gss privacy, which enables encryption of
the payload of every rpc request and response.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
J. Bruce Fields 2006-06-30 01:56:19 -07:00 committed by Linus Torvalds
parent 5c04c46aec
commit 7c9fdcfb1b
2 changed files with 148 additions and 7 deletions

View file

@ -832,6 +832,74 @@ out:
return stat;
}
static inline int
total_buf_len(struct xdr_buf *buf)
{
return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
}
static void
fix_priv_head(struct xdr_buf *buf, int pad)
{
if (buf->page_len == 0) {
/* We need to adjust head and buf->len in tandem in this
* case to make svc_defer() work--it finds the original
* buffer start using buf->len - buf->head[0].iov_len. */
buf->head[0].iov_len -= pad;
}
}
static int
unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
{
u32 priv_len, maj_stat;
int pad, saved_len, remaining_len, offset;
rqstp->rq_sendfile_ok = 0;
priv_len = ntohl(svc_getu32(&buf->head[0]));
if (rqstp->rq_deferred) {
/* Already decrypted last time through! The sequence number
* check at out_seq is unnecessary but harmless: */
goto out_seq;
}
/* buf->len is the number of bytes from the original start of the
* request to the end, where head[0].iov_len is just the bytes
* not yet read from the head, so these two values are different: */
remaining_len = total_buf_len(buf);
if (priv_len > remaining_len)
return -EINVAL;
pad = remaining_len - priv_len;
buf->len -= pad;
fix_priv_head(buf, pad);
/* Maybe it would be better to give gss_unwrap a length parameter: */
saved_len = buf->len;
buf->len = priv_len;
maj_stat = gss_unwrap(ctx, 0, buf);
pad = priv_len - buf->len;
buf->len = saved_len;
buf->len -= pad;
/* The upper layers assume the buffer is aligned on 4-byte boundaries.
* In the krb5p case, at least, the data ends up offset, so we need to
* move it around. */
/* XXX: This is very inefficient. It would be better to either do
* this while we encrypt, or maybe in the receive code, if we can peak
* ahead and work out the service and mechanism there. */
offset = buf->head[0].iov_len % 4;
if (offset) {
buf->buflen = RPCSVC_MAXPAYLOAD;
xdr_shift_buf(buf, offset);
fix_priv_head(buf, pad);
}
if (maj_stat != GSS_S_COMPLETE)
return -EINVAL;
out_seq:
if (ntohl(svc_getu32(&buf->head[0])) != seq)
return -EINVAL;
return 0;
}
struct gss_svc_data {
/* decoded gss client cred: */
struct rpc_gss_wire_cred clcred;
@ -1047,7 +1115,14 @@ svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp)
svc_putu32(resv, 0);
break;
case RPC_GSS_SVC_PRIVACY:
/* currently unsupported */
if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
gc->gc_seq, rsci->mechctx))
goto auth_err;
/* placeholders for length and seq. number: */
svcdata->body_start = resv->iov_base + resv->iov_len;
svc_putu32(resv, 0);
svc_putu32(resv, 0);
break;
default:
goto auth_err;
}
@ -1089,9 +1164,8 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
gsd->body_start = NULL;
/* move accept_stat to right place: */
memcpy(p, p + 2, 4);
/* don't wrap in failure case: */
/* Note: counting on not getting here if call was not even
* accepted! */
/* Don't wrap in failure case: */
/* Counting on not getting here if call was not even accepted! */
if (*p != rpc_success) {
resbuf->head[0].iov_len -= 2 * 4;
goto out;
@ -1138,6 +1212,65 @@ out_err:
return stat;
}
static inline int
svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
{
struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
struct rpc_gss_wire_cred *gc = &gsd->clcred;
struct xdr_buf *resbuf = &rqstp->rq_res;
struct page **inpages = NULL;
u32 *p;
int offset, *len;
int pad;
p = gsd->body_start;
gsd->body_start = NULL;
/* move accept_stat to right place: */
memcpy(p, p + 2, 4);
/* Don't wrap in failure case: */
/* Counting on not getting here if call was not even accepted! */
if (*p != rpc_success) {
resbuf->head[0].iov_len -= 2 * 4;
return 0;
}
p++;
len = p++;
offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
*p++ = htonl(gc->gc_seq);
inpages = resbuf->pages;
/* XXX: Would be better to write some xdr helper functions for
* nfs{2,3,4}xdr.c that place the data right, instead of copying: */
if (resbuf->tail[0].iov_base && rqstp->rq_restailpage == 0) {
BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
+ PAGE_SIZE);
BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
return -ENOMEM;
memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
resbuf->tail[0].iov_base,
resbuf->tail[0].iov_len);
resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
}
if (resbuf->tail[0].iov_base == NULL) {
if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
return -ENOMEM;
resbuf->tail[0].iov_base = resbuf->head[0].iov_base
+ resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
resbuf->tail[0].iov_len = 0;
rqstp->rq_restailpage = 0;
}
if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
return -ENOMEM;
*len = htonl(resbuf->len - offset);
pad = 3 - ((resbuf->len - offset - 1)&3);
p = (u32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
memset(p, 0, pad);
resbuf->tail[0].iov_len += pad;
resbuf->len += pad;
return 0;
}
static int
svcauth_gss_release(struct svc_rqst *rqstp)
{
@ -1152,15 +1285,22 @@ svcauth_gss_release(struct svc_rqst *rqstp)
if (gsd->body_start == NULL)
goto out;
/* normally not set till svc_send, but we need it here: */
resbuf->len = resbuf->head[0].iov_len
+ resbuf->page_len + resbuf->tail[0].iov_len;
/* XXX: what for? Do we mess it up the moment we call svc_putu32
* or whatever? */
resbuf->len = total_buf_len(resbuf);
switch (gc->gc_svc) {
case RPC_GSS_SVC_NONE:
break;
case RPC_GSS_SVC_INTEGRITY:
svcauth_gss_wrap_resp_integ(rqstp);
stat = svcauth_gss_wrap_resp_integ(rqstp);
if (stat)
goto out_err;
break;
case RPC_GSS_SVC_PRIVACY:
stat = svcauth_gss_wrap_resp_priv(rqstp);
if (stat)
goto out_err;
break;
default:
goto out_err;
}

View file

@ -280,6 +280,7 @@ svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
rqstp->rq_res.page_base = 0;
rqstp->rq_res.page_len = 0;
rqstp->rq_res.buflen = PAGE_SIZE;
rqstp->rq_res.tail[0].iov_base = NULL;
rqstp->rq_res.tail[0].iov_len = 0;
/* Will be turned off only in gss privacy case: */
rqstp->rq_sendfile_ok = 1;