[GSoC Encrypted Storage]Read encryption functionality with extents an…

…d chunking LINUX

Rough edges: iov_count considered to be zero, but
should be fixable

src/afs/VNOPS/afs_vnop_read.c

@@ -64,6 +64,7 @@ afs_MemRead(struct vcache *avc, struct uio *auio,
 #endif
     afs_int32 code;
     struct vrequest treq;
+
 
     AFS_STATCNT(afs_MemRead);
     if (avc->vc_error)
@@ -536,6 +537,7 @@ afs_UFSRead(struct vcache *avc, struct uio *auio,
     afs_int32 code;
     int trybusy = 1;
     struct vrequest treq;
+    struct afs_enc_chunk *chunk;
 
     AFS_STATCNT(afs_UFSRead);
     if (avc && avc->vc_error)
@@ -864,6 +866,7 @@ afs_UFSRead(struct vcache *avc, struct uio *auio,
 			printk("end excess extent\n");
 			afs_print_uioinfo(tuiop_e);
 		}
+		chunk = afs_prepare_chunk(tuiop_s1, tuiop1, tuiop_e1);
 
 		afsio_copy(&tuio, &tuio2, tvec2);
 #endif
@@ -934,13 +937,18 @@ afs_UFSRead(struct vcache *avc, struct uio *auio,
 	    AFS_GLOCK();
 #elif defined(AFS_LINUX20_ENV)
 	    AFS_GUNLOCK();
+
+	    if(start){
+	    	osi_rdwr(tfile, tuiop_s, UIO_READ);
+		    afs_chunk_append(chunk, tuiop_s, tuiop_s1);
+		}
 	    code = osi_rdwr(tfile, &tuio, UIO_READ);
-	    afs_print_uiodata(&tuio, tuiop1);
-	    if(start) osi_rdwr(tfile, tuiop_s, UIO_READ);
+	    afs_chunk_append(chunk, tuiop, tuiop1);
 	    if(end){
-	    	printk("trying to get data for last extent\n");
 	    	osi_rdwr(tfile, tuiop_e, UIO_READ);
+	    	afs_chunk_append(chunk, tuiop_e, tuiop_e1);
 	    }
+
 	    AFS_GLOCK();
 #elif defined(AFS_DARWIN80_ENV)
 	    AFS_GUNLOCK();
@@ -992,12 +1000,11 @@ afs_UFSRead(struct vcache *avc, struct uio *auio,
 	 */
 	if(tdc->f.fid.Fid.Vnode%2 == 0){
 		/* Even means file data */		
-		//struct afs_enc_chunk *chunk = afs_get_extent(tuiop_s, tuiop_s1, tuiop, tuiop1, tuiop_e, tuiop_e1);
-		//afs_print_chunk(chunk);
-		//afs_decrypt(chunk);	/* Decrypt chunk */
-
-		//afs_enc_chunk_wb(chunk, tuiop, tuiop1);
-		afs_decrypt1(tuiop, tuiop1);
+
+		afs_print_chunk(chunk);
+		afs_decrypt(chunk);	/* Decrypt chunk */		
+		afs_enc_chunk_wb(chunk, tuiop, tuiop1);
+
 	}
 
 	/* otherwise we've read some, fixup length, etc and continue with next seg */

src/afs/afs.h

@@ -1460,7 +1460,8 @@ afs_set_cr_rgid(afs_ucred_t *cred, gid_t gid) {
 struct afs_enc_chunk{
 
 	char *base;
-	int len;
+	int len;		/* Total length of the chunk */
+	int trans;		/* Length transferred */
 	int uio_start; /* Start index for the data to be read */
 	int uio_len;   /* Length of the data to be read */
 };

src/afs/afs_enc.c

@@ -260,8 +260,8 @@ void afs_print_chunk(struct afs_enc_chunk *chunk){
 
 	printk("Size: %d\nStart: %d\nEnd: %d\n", chunk->len, chunk->uio_start, chunk->uio_len);
 	afs_int32 i;
-	for(i=0;i<chunk->uio_len;i++);
-		//printk("%c", chunk->base[chunk->uio_start+i]);
+	for(i=0;i<chunk->len;i++)
+		printk("%c", chunk->base[i]);
 }
 
 void afs_enc_chunk_wb(struct afs_enc_chunk *chunk, struct uio *data, struct uio *basis){
@@ -272,12 +272,13 @@ void afs_enc_chunk_wb(struct afs_enc_chunk *chunk, struct uio *data, struct uio
 	while(chunk_len){
 		/* Transfer the chunk back to the tuiop structure */
 
-		space = basis->uio_iov[iov_no].iov_len - data->uio_iov[iov_no].iov_len;
+		space = basis->uio_iov[iov_no].iov_len;
 		char *d = (char *)basis->uio_iov[iov_no].iov_base;
 		i=0;
 		while(i<space && chunk_len){
-			d[i] = chunk->base[ind++];
+			d[i] = chunk->base[chunk->uio_start+ind];
 			i++;
+			ind++;
 			chunk_len--;
 		}
 
@@ -286,6 +287,19 @@ void afs_enc_chunk_wb(struct afs_enc_chunk *chunk, struct uio *data, struct uio
 }
 
 
+void afs_chunk_append(struct afs_enc_chunk *ch, struct uio *data, struct uio *basis){
+
+	/* Appends the data to the chunk */
+
+	if(basis!=NULL){
+
+		char *temp = (char *)basis->uio_iov[0].iov_base;
+		int i=0;
+		for(i=0;i<basis->uio_iov[0].iov_len;i++)
+			ch->base[i+ch->trans] = temp[i];
+		ch->trans += basis->uio_iov[0].iov_len;
+	}
+}
 
 struct afs_enc_chunk *afs_get_extent(struct uio *s, struct uio *s1, struct uio *t, struct uio *t1, struct uio *e, struct uio *e1)
 {
@@ -343,7 +357,21 @@ struct afs_enc_chunk *afs_get_extent(struct uio *s, struct uio *s1, struct uio *
 
 }
 
+struct afs_enc_chunk *afs_prepare_chunk(struct uio *s, struct uio *t, struct uio *e){
 
+	/* Sets the various checkpoints for the chunk which is to be read */
+
+	int len = (s?s->uio_iov[0].iov_len:0) + (t?t->uio_iov[0].iov_len:0) + (e?e->uio_iov[0].iov_len:0);
+
+	struct afs_enc_chunk *chunk = (struct afs_enc_chunk *)osi_Alloc(sizeof(struct afs_enc_chunk));
+
+	chunk->uio_start = s?s->uio_iov[0].iov_len:0;
+	chunk->uio_len = t?t->uio_iov[0].iov_len:0;
+	chunk->len = len;
+	chunk->base = (char *)osi_Alloc(len * sizeof(char));
+
+	return chunk;
+}
 
 
 

src/afs/afs_prototypes.h

@@ -1356,6 +1356,8 @@ extern unsigned long int do_mod64(long long int x, long long int y);
 extern struct afs_enc_chunk *afs_get_extent(struct uio *s, struct uio *s1, struct uio *t, struct uio *t1, struct uio *e, struct uio *e1);
 extern void afs_print_chunk(struct afs_enc_chunk *chunk);
 void afs_enc_chunk_wb(struct afs_enc_chunk *chunk, struct uio *data, struct uio *basis);
+struct afs_enc_chunk *afs_prepare_chunk(struct uio *s, struct uio *p, struct uio *e);
+void afs_chunk_append(struct afs_enc_chunk *ch, struct uio *data, struct uio *basis);
 /* Prototypes for generated files that aren't really in src/afs/ */
 
 /* afs_uuid.c */