[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
Linus Torvalds
parent
5c04c46aec
commit
7c9fdcfb1b
2 changed files with 148 additions and 7 deletions
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@ -832,6 +832,74 @@ out:
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return stat;
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}
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static inline int
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total_buf_len(struct xdr_buf *buf)
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{
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return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
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}
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static void
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fix_priv_head(struct xdr_buf *buf, int pad)
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{
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if (buf->page_len == 0) {
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/* We need to adjust head and buf->len in tandem in this
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* case to make svc_defer() work--it finds the original
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* buffer start using buf->len - buf->head[0].iov_len. */
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buf->head[0].iov_len -= pad;
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}
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}
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static int
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unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
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{
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u32 priv_len, maj_stat;
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int pad, saved_len, remaining_len, offset;
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rqstp->rq_sendfile_ok = 0;
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priv_len = ntohl(svc_getu32(&buf->head[0]));
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if (rqstp->rq_deferred) {
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/* Already decrypted last time through! The sequence number
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* check at out_seq is unnecessary but harmless: */
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goto out_seq;
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}
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/* buf->len is the number of bytes from the original start of the
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* request to the end, where head[0].iov_len is just the bytes
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* not yet read from the head, so these two values are different: */
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remaining_len = total_buf_len(buf);
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if (priv_len > remaining_len)
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return -EINVAL;
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pad = remaining_len - priv_len;
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buf->len -= pad;
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fix_priv_head(buf, pad);
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/* Maybe it would be better to give gss_unwrap a length parameter: */
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saved_len = buf->len;
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buf->len = priv_len;
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maj_stat = gss_unwrap(ctx, 0, buf);
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pad = priv_len - buf->len;
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buf->len = saved_len;
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buf->len -= pad;
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/* The upper layers assume the buffer is aligned on 4-byte boundaries.
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* In the krb5p case, at least, the data ends up offset, so we need to
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* move it around. */
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/* XXX: This is very inefficient. It would be better to either do
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* this while we encrypt, or maybe in the receive code, if we can peak
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* ahead and work out the service and mechanism there. */
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offset = buf->head[0].iov_len % 4;
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if (offset) {
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buf->buflen = RPCSVC_MAXPAYLOAD;
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xdr_shift_buf(buf, offset);
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fix_priv_head(buf, pad);
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}
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if (maj_stat != GSS_S_COMPLETE)
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return -EINVAL;
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out_seq:
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if (ntohl(svc_getu32(&buf->head[0])) != seq)
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return -EINVAL;
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return 0;
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}
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struct gss_svc_data {
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/* decoded gss client cred: */
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struct rpc_gss_wire_cred clcred;
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@ -1047,7 +1115,14 @@ svcauth_gss_accept(struct svc_rqst *rqstp, u32 *authp)
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svc_putu32(resv, 0);
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break;
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case RPC_GSS_SVC_PRIVACY:
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/* currently unsupported */
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if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
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gc->gc_seq, rsci->mechctx))
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goto auth_err;
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/* placeholders for length and seq. number: */
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svcdata->body_start = resv->iov_base + resv->iov_len;
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svc_putu32(resv, 0);
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svc_putu32(resv, 0);
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break;
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default:
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goto auth_err;
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}
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@ -1089,9 +1164,8 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
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gsd->body_start = NULL;
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/* move accept_stat to right place: */
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memcpy(p, p + 2, 4);
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/* don't wrap in failure case: */
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/* Note: counting on not getting here if call was not even
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* accepted! */
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/* Don't wrap in failure case: */
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/* Counting on not getting here if call was not even accepted! */
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if (*p != rpc_success) {
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resbuf->head[0].iov_len -= 2 * 4;
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goto out;
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@ -1138,6 +1212,65 @@ out_err:
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return stat;
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}
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static inline int
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svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
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{
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struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
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struct rpc_gss_wire_cred *gc = &gsd->clcred;
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struct xdr_buf *resbuf = &rqstp->rq_res;
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struct page **inpages = NULL;
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u32 *p;
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int offset, *len;
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int pad;
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p = gsd->body_start;
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gsd->body_start = NULL;
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/* move accept_stat to right place: */
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memcpy(p, p + 2, 4);
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/* Don't wrap in failure case: */
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/* Counting on not getting here if call was not even accepted! */
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if (*p != rpc_success) {
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resbuf->head[0].iov_len -= 2 * 4;
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return 0;
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}
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p++;
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len = p++;
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offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
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*p++ = htonl(gc->gc_seq);
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inpages = resbuf->pages;
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/* XXX: Would be better to write some xdr helper functions for
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* nfs{2,3,4}xdr.c that place the data right, instead of copying: */
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if (resbuf->tail[0].iov_base && rqstp->rq_restailpage == 0) {
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BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
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+ PAGE_SIZE);
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BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
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if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
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+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
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return -ENOMEM;
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memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
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resbuf->tail[0].iov_base,
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resbuf->tail[0].iov_len);
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resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
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}
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if (resbuf->tail[0].iov_base == NULL) {
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if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
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return -ENOMEM;
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resbuf->tail[0].iov_base = resbuf->head[0].iov_base
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+ resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
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resbuf->tail[0].iov_len = 0;
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rqstp->rq_restailpage = 0;
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}
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if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
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return -ENOMEM;
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*len = htonl(resbuf->len - offset);
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pad = 3 - ((resbuf->len - offset - 1)&3);
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p = (u32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
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memset(p, 0, pad);
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resbuf->tail[0].iov_len += pad;
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resbuf->len += pad;
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return 0;
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}
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static int
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svcauth_gss_release(struct svc_rqst *rqstp)
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{
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@ -1152,15 +1285,22 @@ svcauth_gss_release(struct svc_rqst *rqstp)
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if (gsd->body_start == NULL)
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goto out;
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/* normally not set till svc_send, but we need it here: */
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resbuf->len = resbuf->head[0].iov_len
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+ resbuf->page_len + resbuf->tail[0].iov_len;
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/* XXX: what for? Do we mess it up the moment we call svc_putu32
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* or whatever? */
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resbuf->len = total_buf_len(resbuf);
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switch (gc->gc_svc) {
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case RPC_GSS_SVC_NONE:
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break;
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case RPC_GSS_SVC_INTEGRITY:
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svcauth_gss_wrap_resp_integ(rqstp);
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stat = svcauth_gss_wrap_resp_integ(rqstp);
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if (stat)
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goto out_err;
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break;
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case RPC_GSS_SVC_PRIVACY:
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stat = svcauth_gss_wrap_resp_priv(rqstp);
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if (stat)
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goto out_err;
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break;
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default:
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goto out_err;
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}
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@ -280,6 +280,7 @@ svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
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rqstp->rq_res.page_base = 0;
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rqstp->rq_res.page_len = 0;
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rqstp->rq_res.buflen = PAGE_SIZE;
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rqstp->rq_res.tail[0].iov_base = NULL;
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rqstp->rq_res.tail[0].iov_len = 0;
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/* Will be turned off only in gss privacy case: */
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rqstp->rq_sendfile_ok = 1;
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