CIFS: Add readdir support for SMB2

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 168 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a1314f99b4cc..21b3a652e192 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -45,6 +45,7 @@
 #include "ntlmssp.h"
 #include "smb2status.h"
 #include "smb2glob.h"
+#include "cifspdu.h"
 
 /*
  *  The following table defines the expected "StructureSize" of SMB2 requests
@@ -1603,6 +1604,173 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
 	return rc;
 }
 
+static unsigned int
+num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
+{
+	int len;
+	unsigned int entrycount = 0;
+	unsigned int next_offset = 0;
+	FILE_DIRECTORY_INFO *entryptr;
+
+	if (bufstart == NULL)
+		return 0;
+
+	entryptr = (FILE_DIRECTORY_INFO *)bufstart;
+
+	while (1) {
+		entryptr = (FILE_DIRECTORY_INFO *)
+					((char *)entryptr + next_offset);
+
+		if ((char *)entryptr + size > end_of_buf) {
+			cERROR(1, "malformed search entry would overflow");
+			break;
+		}
+
+		len = le32_to_cpu(entryptr->FileNameLength);
+		if ((char *)entryptr + len + size > end_of_buf) {
+			cERROR(1, "directory entry name would overflow frame "
+				  "end of buf %p", end_of_buf);
+			break;
+		}
+
+		*lastentry = (char *)entryptr;
+		entrycount++;
+
+		next_offset = le32_to_cpu(entryptr->NextEntryOffset);
+		if (!next_offset)
+			break;
+	}
+
+	return entrycount;
+}
+
+/*
+ * Readdir/FindFirst
+ */
+int
+SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
+		     u64 persistent_fid, u64 volatile_fid, int index,
+		     struct cifs_search_info *srch_inf)
+{
+	struct smb2_query_directory_req *req;
+	struct smb2_query_directory_rsp *rsp = NULL;
+	struct kvec iov[2];
+	int rc = 0;
+	int len;
+	int resp_buftype;
+	unsigned char *bufptr;
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses = tcon->ses;
+	__le16 asteriks = cpu_to_le16('*');
+	char *end_of_smb;
+	unsigned int output_size = CIFSMaxBufSize;
+	size_t info_buf_size;
+
+	if (ses && (ses->server))
+		server = ses->server;
+	else
+		return -EIO;
+
+	rc = small_smb2_init(SMB2_QUERY_DIRECTORY, tcon, (void **) &req);
+	if (rc)
+		return rc;
+
+	switch (srch_inf->info_level) {
+	case SMB_FIND_FILE_DIRECTORY_INFO:
+		req->FileInformationClass = FILE_DIRECTORY_INFORMATION;
+		info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
+		break;
+	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
+		req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
+		info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
+		break;
+	default:
+		cERROR(1, "info level %u isn't supported",
+		       srch_inf->info_level);
+		rc = -EINVAL;
+		goto qdir_exit;
+	}
+
+	req->FileIndex = cpu_to_le32(index);
+	req->PersistentFileId = persistent_fid;
+	req->VolatileFileId = volatile_fid;
+
+	len = 0x2;
+	bufptr = req->Buffer;
+	memcpy(bufptr, &asteriks, len);
+
+	req->FileNameOffset =
+		cpu_to_le16(sizeof(struct smb2_query_directory_req) - 1 - 4);
+	req->FileNameLength = cpu_to_le16(len);
+	/*
+	 * BB could be 30 bytes or so longer if we used SMB2 specific
+	 * buffer lengths, but this is safe and close enough.
+	 */
+	output_size = min_t(unsigned int, output_size, server->maxBuf);
+	output_size = min_t(unsigned int, output_size, 2 << 15);
+	req->OutputBufferLength = cpu_to_le32(output_size);
+
+	iov[0].iov_base = (char *)req;
+	/* 4 for RFC1001 length and 1 for Buffer */
+	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
+
+	iov[1].iov_base = (char *)(req->Buffer);
+	iov[1].iov_len = len;
+
+	inc_rfc1001_len(req, len - 1 /* Buffer */);
+
+	rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, 0);
+	if (rc) {
+		cifs_stats_fail_inc(tcon, SMB2_QUERY_DIRECTORY_HE);
+		goto qdir_exit;
+	}
+	rsp = (struct smb2_query_directory_rsp *)iov[0].iov_base;
+
+	rc = validate_buf(le16_to_cpu(rsp->OutputBufferOffset),
+			  le32_to_cpu(rsp->OutputBufferLength), &rsp->hdr,
+			  info_buf_size);
+	if (rc)
+		goto qdir_exit;
+
+	srch_inf->unicode = true;
+
+	if (srch_inf->ntwrk_buf_start) {
+		if (srch_inf->smallBuf)
+			cifs_small_buf_release(srch_inf->ntwrk_buf_start);
+		else
+			cifs_buf_release(srch_inf->ntwrk_buf_start);
+	}
+	srch_inf->ntwrk_buf_start = (char *)rsp;
+	srch_inf->srch_entries_start = srch_inf->last_entry = 4 /* rfclen */ +
+		(char *)&rsp->hdr + le16_to_cpu(rsp->OutputBufferOffset);
+	/* 4 for rfc1002 length field */
+	end_of_smb = get_rfc1002_length(rsp) + 4 + (char *)&rsp->hdr;
+	srch_inf->entries_in_buffer =
+			num_entries(srch_inf->srch_entries_start, end_of_smb,
+				    &srch_inf->last_entry, info_buf_size);
+	srch_inf->index_of_last_entry += srch_inf->entries_in_buffer;
+	cFYI(1, "num entries %d last_index %lld srch start %p srch end %p",
+		srch_inf->entries_in_buffer, srch_inf->index_of_last_entry,
+		srch_inf->srch_entries_start, srch_inf->last_entry);
+	if (resp_buftype == CIFS_LARGE_BUFFER)
+		srch_inf->smallBuf = false;
+	else if (resp_buftype == CIFS_SMALL_BUFFER)
+		srch_inf->smallBuf = true;
+	else
+		cERROR(1, "illegal search buffer type");
+
+	if (rsp->hdr.Status == STATUS_NO_MORE_FILES)
+		srch_inf->endOfSearch = 1;
+	else
+		srch_inf->endOfSearch = 0;
+
+	return rc;
+
+qdir_exit:
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}
+
 static int
 send_set_info(const unsigned int xid, struct cifs_tcon *tcon,
 	       u64 persistent_fid, u64 volatile_fid, u32 pid, int info_class,