[patch] fixes for smbfs readdir in 2.2.18-pre18

From: Urban Widmark (urban@svenskatest.se)
Date: Sat Nov 04 2000 - 10:02:35 EST


Hello

The old problem with smbfs and listing directories continue. The change of
infolevel that was thought to fix things in 2.2.14 didn't fix everything.
Here is a patch for another thing smbfs doesn't really do right,
apparently.

There is a mismatch between the negotiated maximum transfer size and the
number of bytes smbfs tells the server it may return. This patch changes
it from using 2 completely magic values to use other magic values based on
the negotiated size.

There are mixed reports on this for some servers (OS/2 & NetApp), no luck
for AS/400 (but they send unicode stuff even when not negotiated). But it
fixes problems vs the much more common NT4 (and win2k?) servers.

I'd love to see this in 2.2.18-pre19.

/Urban

diff -ur -X exclude linux-2.2.18-pre18-orig/fs/smbfs/ChangeLog linux-2.2.18-pre18-smbfs/fs/smbfs/ChangeLog
--- linux-2.2.18-pre18-orig/fs/smbfs/ChangeLog Sat Nov 4 11:38:56 2000
+++ linux-2.2.18-pre18-smbfs/fs/smbfs/ChangeLog Sat Nov 4 11:59:11 2000
@@ -1,5 +1,11 @@
 ChangeLog for smbfs.
 
+2000-11-04 Urban Widmark <urban@svenskatest.se>
+
+ * proc.c, sock.c: adjust max parameters & max data to follow max_xmit
+ lots of servers were having find_next trouble with this.
+ * proc.c: use documented write method of truncating (NetApp fix)
+
 2000-09-01 Urban Widmark <urban@svenskatest.se>
 
         * proc.c: add back lanman2 support (OS/2 and others)
diff -ur -X exclude linux-2.2.18-pre18-orig/fs/smbfs/proc.c linux-2.2.18-pre18-smbfs/fs/smbfs/proc.c
--- linux-2.2.18-pre18-orig/fs/smbfs/proc.c Sat Nov 4 11:38:56 2000
+++ linux-2.2.18-pre18-smbfs/fs/smbfs/proc.c Sat Nov 4 12:07:58 2000
@@ -385,22 +385,16 @@
 }
 
 /*
- * Returns the maximum read or write size for the current packet size
- * and max_xmit value.
+ * Returns the maximum read or write size for the "payload". Making all of the
+ * packet fit within the negotiated max_xmit size.
+ *
  * N.B. Since this value is usually computed before locking the server,
  * the server's packet size must never be decreased!
  */
-static int
+static inline int
 smb_get_xmitsize(struct smb_sb_info *server, int overhead)
 {
- int size = server->packet_size;
-
- /*
- * Start with the smaller of packet size and max_xmit ...
- */
- if (size > server->opt.max_xmit)
- size = server->opt.max_xmit;
- return size - overhead;
+ return server->opt.max_xmit - overhead;
 }
 
 /*
@@ -751,6 +745,23 @@
                 server->opt.protocol, server->opt.max_xmit, server->conn_pid,
                 server->opt.capabilities);
 
+ /* Make sure we can fit a message of the negotiated size in our
+ packet buffer. */
+ if (server->opt.max_xmit > server->packet_size) {
+ int len = smb_round_length(server->opt.max_xmit);
+ char *buf = smb_vmalloc(len);
+ if (buf) {
+ server->packet = buf;
+ server->packet_size = len;
+ } else {
+ /* else continue with the too small buffer? */
+ PARANOIA("Failed to allocate new packet buffer: "
+ "max_xmit=%d, packet_size=%d\n",
+ server->opt.max_xmit, server->packet_size);
+ server->opt.max_xmit = server->packet_size;
+ }
+ }
+
 out:
 #ifdef SMB_RETRY_INTR
         wake_up_interruptible(&server->wait);
@@ -1348,17 +1359,16 @@
         smb_lock_server(server);
 
       retry:
- p = smb_setup_header(server, SMBwrite, 5, 0);
+ p = smb_setup_header(server, SMBwrite, 5, 3);
         WSET(server->packet, smb_vwv0, fid);
         WSET(server->packet, smb_vwv1, 0);
         DSET(server->packet, smb_vwv2, length);
         WSET(server->packet, smb_vwv4, 0);
- *p++ = 4;
- *p++ = 0;
- smb_setup_bcc(server, p);
 
- if ((result = smb_request_ok(server, SMBwrite, 1, 0)) < 0)
- {
+ *p++ = 1;
+ WSET(p, 0, 0);
+
+ if ((result = smb_request_ok(server, SMBwrite, 1, 0)) < 0) {
                 if (smb_retry(server))
                         goto retry;
                 goto out;
@@ -1487,8 +1497,8 @@
 smb_proc_readdir_long(struct smb_sb_info *server, struct dentry *dir, int fpos,
                       void *cachep)
 {
- unsigned char *p;
- char *mask, *lastname, *param = server->temp_buf;
+ unsigned char *p, *lastname;
+ char *mask, *param = server->temp_buf;
         __u16 command;
         int first, entries, entries_seen;
 
@@ -1521,7 +1531,7 @@
          * Encode the initial path
          */
         mask = param + 12;
- mask_len = smb_encode_path(server, mask, dir, &star);
+ mask_len = smb_encode_path(server, mask, dir, &star) - 1;
         if (mask_len < 0) {
                 entries = mask_len;
                 goto unlock_return;
@@ -1613,31 +1623,41 @@
                 if (ff_searchcount == 0)
                         break;
 
- /* we might need the lastname for continuations */
+ /*
+ * We might need the lastname for continuations.
+ *
+ * Note that some servers (win95) point to the filename and
+ * others (NT4, Samba using NT1) to the dir entry. We assume
+ * here that those who do not point to a filename do not need
+ * this info to continue the listing.
+ */
                 mask_len = 0;
- if (ff_lastname > 0) {
+ if (ff_lastname > 0 && ff_lastname < resp_data_len) {
                         lastname = resp_data + ff_lastname;
                         switch (info_level) {
                         case 260:
- if (ff_lastname < resp_data_len)
- mask_len = resp_data_len - ff_lastname;
+ mask_len = resp_data_len - ff_lastname;
                                 break;
                         case 1:
- /* Win NT 4.0 doesn't set the length byte */
- lastname++;
- if (ff_lastname + 2 < resp_data_len)
- mask_len = strlen(lastname);
+ /* lastname points to a length byte */
+ mask_len = *lastname++;
+ if (ff_lastname + 1 + mask_len > resp_data_len)
+ mask_len = resp_data_len - ff_lastname - 1;
                                 break;
                         }
                         /*
                          * Update the mask string for the next message.
                          */
+ if (mask_len < 0)
+ mask_len = 0;
                         if (mask_len > 255)
                                 mask_len = 255;
                         if (mask_len)
                                 strncpy(mask, lastname, mask_len);
                 }
                 mask[mask_len] = 0;
+ mask_len = strlen(mask); /* find the actual string len */
+
 
                 /* Now we are ready to parse smb directory entries. */
 
diff -ur -X exclude linux-2.2.18-pre18-orig/fs/smbfs/sock.c linux-2.2.18-pre18-smbfs/fs/smbfs/sock.c
--- linux-2.2.18-pre18-orig/fs/smbfs/sock.c Sat Nov 4 11:38:56 2000
+++ linux-2.2.18-pre18-smbfs/fs/smbfs/sock.c Sat Nov 4 11:52:32 2000
@@ -473,14 +473,12 @@
         unsigned int total_p = 0, total_d = 0, buf_len = 0;
         int result;
 
- while (1)
- {
+ while (1) {
                 result = smb_receive(server);
                 if (result < 0)
                         goto out;
                 inbuf = server->packet;
- if (server->rcls != 0)
- {
+ if (server->rcls != 0) {
                         *parm = *data = inbuf;
                         *ldata = *lparm = 0;
                         goto out;
@@ -504,13 +502,11 @@
                 parm_len += parm_count;
                 data_len += data_count;
 
- if (!rcv_buf)
- {
+ if (!rcv_buf) {
                         /*
                          * Check for fast track processing ... just this packet.
                          */
- if (parm_count == parm_tot && data_count == data_tot)
- {
+ if (parm_count == parm_tot && data_count == data_tot) {
                                 VERBOSE("fast track, parm=%u %u %u, data=%u %u %u\n",
                                         parm_disp, parm_offset, parm_count,
                                         data_disp, data_offset, data_count);
@@ -520,12 +516,10 @@
                                 goto success;
                         }
 
- if (parm_tot > TRANS2_MAX_TRANSFER ||
- data_tot > TRANS2_MAX_TRANSFER)
- goto out_too_long;
-
                         /*
- * Save the total parameter and data length.
+ * Allocate a new buffer for receiving multiple packets
+ * into. If we stick to the negotiated max_xmit this
+ * shouldn't have to happen.
                          */
                         total_d = data_tot;
                         total_p = parm_tot;
@@ -534,14 +528,15 @@
                         if (server->packet_size > buf_len)
                                 buf_len = server->packet_size;
                         buf_len = smb_round_length(buf_len);
+ if (buf_len > SMB_MAX_PACKET_SIZE)
+ goto out_no_mem;
 
                         rcv_buf = smb_vmalloc(buf_len);
                         if (!rcv_buf)
                                 goto out_no_mem;
                         *parm = rcv_buf;
                         *data = rcv_buf + total_p;
- }
- else if (data_tot > total_d || parm_tot > total_p)
+ } else if (data_tot > total_d || parm_tot > total_p)
                         goto out_data_grew;
 
                 if (parm_disp + parm_count > total_p)
@@ -568,8 +563,7 @@
          * old one, in which case we just copy the data.
          */
         inbuf = server->packet;
- if (buf_len >= server->packet_size)
- {
+ if (buf_len >= server->packet_size) {
                 server->packet_size = buf_len;
                 server->packet = rcv_buf;
                 rcv_buf = inbuf;
@@ -713,6 +707,7 @@
         struct socket *sock = server_sock(server);
         struct scm_cookie scm;
         int err;
+ int mparam, mdata;
 
         /* I know the following is very ugly, but I want to build the
            smb packet as efficiently as possible. */
@@ -733,19 +728,30 @@
         struct iovec iov[4];
         struct msghdr msg;
 
- /* N.B. This test isn't valid! packet_size may be < max_xmit */
+ /* FIXME! this test needs to include SMB overhead too, I think ... */
         if ((bcc + oparam) > server->opt.max_xmit)
- {
                 return -ENOMEM;
- }
         p = smb_setup_header(server, SMBtrans2, smb_parameters, bcc);
 
+ /*
+ * max parameters + max data + max setup == max_xmit to make NT4 happy
+ * and not abort the transfer or split into multiple packets.
+ *
+ * -100 is to make room for headers, which OS/2 seems to include in the
+ * size calculation NT4 does not?
+ */
+ mparam = SMB_TRANS2_MAX_PARAM;
+ mdata = server->opt.max_xmit - mparam - 100;
+ if (mdata < 1024) {
+ mdata = 1024;
+ mparam = 20;
+ }
+
         WSET(server->packet, smb_tpscnt, lparam);
         WSET(server->packet, smb_tdscnt, ldata);
- /* N.B. these values should reflect out current packet size */
- WSET(server->packet, smb_mprcnt, TRANS2_MAX_TRANSFER);
- WSET(server->packet, smb_mdrcnt, TRANS2_MAX_TRANSFER);
- WSET(server->packet, smb_msrcnt, 0);
+ WSET(server->packet, smb_mprcnt, mparam);
+ WSET(server->packet, smb_mdrcnt, mdata);
+ WSET(server->packet, smb_msrcnt, 0); /* max setup always 0 ? */
         WSET(server->packet, smb_flags, 0);
         DSET(server->packet, smb_timeout, 0);
         WSET(server->packet, smb_pscnt, lparam);
@@ -777,8 +783,7 @@
         iov[3].iov_len = ldata;
 
         err = scm_send(sock, &msg, &scm);
- if (err >= 0)
- {
+ if (err >= 0) {
                 err = sock->ops->sendmsg(sock, &msg, packet_length, &scm);
                 scm_destroy(&scm);
         }
diff -ur -X exclude linux-2.2.18-pre18-orig/include/linux/smb.h linux-2.2.18-pre18-smbfs/include/linux/smb.h
--- linux-2.2.18-pre18-orig/include/linux/smb.h Sat Nov 4 11:38:57 2000
+++ linux-2.2.18-pre18-smbfs/include/linux/smb.h Sat Nov 4 12:20:57 2000
@@ -119,11 +119,13 @@
 
 #define SMB_HEADER_LEN 37 /* includes everything up to, but not
                                  * including smb_bcc */
-#define SMB_DEF_MAX_XMIT 32768
-#define SMB_INITIAL_PACKET_SIZE 4000
 
-/* Allocate max. 1 page */
-#define TRANS2_MAX_TRANSFER (4096-17)
+#define SMB_INITIAL_PACKET_SIZE 4000
+#define SMB_MAX_PACKET_SIZE 32768
+
+/* reserve this much space for trans2 parameters. Shouldn't have to be more
+ than 10 or so, but OS/2 seems happier like this. */
+#define SMB_TRANS2_MAX_PARAM 64
 
 #endif
 #endif

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This archive was generated by hypermail 2b29 : Tue Nov 07 2000 - 21:00:16 EST