RPCSEC_GSS: Simplify rpcsec_gss crypto code

 Factor out some code that will be shared by privacy crypto routines

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index ee6ae74..2baf93f 100644 (file)
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -139,6 +139,82 @@ buf_to_sg(struct scatterlist *sg, char *ptr, int len) {
        sg->length = len;
 }
 
+static int
+process_xdr_buf(struct xdr_buf *buf, int offset, int len,
+               int (*actor)(struct scatterlist *, void *), void *data)
+{
+       int i, page_len, thislen, page_offset, ret = 0;
+       struct scatterlist      sg[1];
+
+       if (offset >= buf->head[0].iov_len) {
+               offset -= buf->head[0].iov_len;
+       } else {
+               thislen = buf->head[0].iov_len - offset;
+               if (thislen > len)
+                       thislen = len;
+               buf_to_sg(sg, buf->head[0].iov_base + offset, thislen);
+               ret = actor(sg, data);
+               if (ret)
+                       goto out;
+               offset = 0;
+               len -= thislen;
+       }
+       if (len == 0)
+               goto out;
+
+       if (offset >= buf->page_len) {
+               offset -= buf->page_len;
+       } else {
+               page_len = buf->page_len - offset;
+               if (page_len > len)
+                       page_len = len;
+               len -= page_len;
+               page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
+               i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
+               thislen = PAGE_CACHE_SIZE - page_offset;
+               do {
+                       if (thislen > page_len)
+                               thislen = page_len;
+                       sg->page = buf->pages[i];
+                       sg->offset = page_offset;
+                       sg->length = thislen;
+                       ret = actor(sg, data);
+                       if (ret)
+                               goto out;
+                       page_len -= thislen;
+                       i++;
+                       page_offset = 0;
+                       thislen = PAGE_CACHE_SIZE;
+               } while (page_len != 0);
+               offset = 0;
+       }
+       if (len == 0)
+               goto out;
+
+       if (offset < buf->tail[0].iov_len) {
+               thislen = buf->tail[0].iov_len - offset;
+               if (thislen > len)
+                       thislen = len;
+               buf_to_sg(sg, buf->tail[0].iov_base + offset, thislen);
+               ret = actor(sg, data);
+               len -= thislen;
+       }
+       if (len != 0)
+               ret = -EINVAL;
+out:
+       return ret;
+}
+
+static int
+checksummer(struct scatterlist *sg, void *data)
+{
+       struct crypto_tfm *tfm = (struct crypto_tfm *)data;
+
+       crypto_digest_update(tfm, sg, 1);
+
+       return 0;
+}
+
 /* checksum the plaintext data and hdrlen bytes of the token header */
 s32
 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
@@ -148,8 +224,6 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
        struct crypto_tfm               *tfm = NULL; /* XXX add to ctx? */
        struct scatterlist              sg[1];
        u32                             code = GSS_S_FAILURE;
-       int                             len, thislen, offset;
-       int                             i;
 
        switch (cksumtype) {
                case CKSUMTYPE_RSA_MD5:
@@ -169,33 +243,7 @@ make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
        crypto_digest_init(tfm);
        buf_to_sg(sg, header, hdrlen);
        crypto_digest_update(tfm, sg, 1);
-       if (body->head[0].iov_len) {
-               buf_to_sg(sg, body->head[0].iov_base, body->head[0].iov_len);
-               crypto_digest_update(tfm, sg, 1);
-       }
-
-       len = body->page_len;
-       if (len != 0) {
-               offset = body->page_base & (PAGE_CACHE_SIZE - 1);
-               i = body->page_base >> PAGE_CACHE_SHIFT;
-               thislen = PAGE_CACHE_SIZE - offset;
-               do {
-                       if (thislen > len)
-                               thislen = len;
-                       sg->page = body->pages[i];
-                       sg->offset = offset;
-                       sg->length = thislen;
-                       crypto_digest_update(tfm, sg, 1);
-                       len -= thislen;
-                       i++;
-                       offset = 0;
-                       thislen = PAGE_CACHE_SIZE;
-               } while(len != 0);
-       }
-       if (body->tail[0].iov_len) {
-               buf_to_sg(sg, body->tail[0].iov_base, body->tail[0].iov_len);
-               crypto_digest_update(tfm, sg, 1);
-       }
+       process_xdr_buf(body, 0, body->len, checksummer, tfm);
        crypto_digest_final(tfm, cksum->data);
        code = 0;
 out: