src/patches/suse-2.6.27.39/patches.fixes/cifs-fix-ssh-tunneled-mounts

   1 From: Suresh Jayaraman <sjayaraman@suse.de>
   2 Subject: [PATCH] cifs: fix broken mounts when a SSH tunnel is used (try #4)
   3 References: bnc#527754
   4 Patch-mainline: in cifs-2.6.git (merge expected in 2.6.32-rcX)
   5
   6     It seems there is a regression that got introduced while Jeff fixed
   7     all the mount/umount races. While attempting to find whether a tcp
   8     session is already existing, we were not checking whether the "port"
   9     used are the same. When a second mount is attempted with a different
  10     "port=" option, it is being ignored. Because of this the cifs mounts
  11     that uses a SSH tunnel appears to be broken.
  12
  13     Steps to reproduce:
  14
  15     1. create 2 shares
  16     # SSH Tunnel a SMB session
  17     2. ssh -f -L 6111:127.0.0.1:445 root@localhost "sleep 86400"
  18     3. ssh -f -L 6222:127.0.0.1:445 root@localhost "sleep 86400"
  19     4. tcpdump -i lo 6111 &
  20     5. mkdir -p /mnt/mnt1
  21     6. mkdir -p /mnt/mnt2
  22     7. mount.cifs //localhost/a /mnt/mnt1 -o username=guest,ip=127.0.0.1,port=6111
  23     #(shows tcpdump activity on port 6111)
  24     8. mount.cifs //localhost/b /mnt/mnt2 -o username=guest,ip=127.0.0.1,port=6222
  25     #(shows tcpdump activity only on port 6111 and not on 6222
  26
  27     Fix by adding a check to compare the port _only_ if the user tries to
  28     override the tcp port with "port=" option, before deciding that an
  29     existing tcp session is found. Also, clean up a bit by replacing
  30     if-else if by a switch statment while at it as suggested by Jeff.
  31
  32 Reviewed-by: Jeff Layton <jlayton@redhat.com>
  33 Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
  34 Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
  35 Signed-off-by: Steve French <sfrench@us.ibm.com>
  36 ---
  37  fs/cifs/connect.c |   44 ++++++++++++++++++++++++++++++++++----------
  38  1 file changed, 34 insertions(+), 10 deletions(-)
  39
  40 Index: linux-2.6.27-SLE11_BRANCH/fs/cifs/connect.c
  41 ===================================================================
  42 --- linux-2.6.27-SLE11_BRANCH.orig/fs/cifs/connect.c
  43 +++ linux-2.6.27-SLE11_BRANCH/fs/cifs/connect.c
  44 @@ -35,6 +35,7 @@
  45  #include <linux/freezer.h>
  46  #include <asm/uaccess.h>
  47  #include <asm/processor.h>
  48 +#include <net/ipv6.h>
  49  #include "cifspdu.h"
  50  #include "cifsglob.h"
  51  #include "cifsproto.h"
  52 @@ -1349,7 +1350,7 @@ cifs_parse_mount_options(char *options,
  53  }
  54
  55  static struct TCP_Server_Info *
  56 -cifs_find_tcp_session(struct sockaddr_storage *addr)
  57 +cifs_find_tcp_session(struct sockaddr_storage *addr, unsigned short int port)
  58  {
  59         struct list_head *tmp;
  60         struct TCP_Server_Info *server;
  61 @@ -1369,14 +1370,37 @@ cifs_find_tcp_session(struct sockaddr_st
  62                 if (server->tcpStatus == CifsNew)
  63                         continue;
  64
  65 -               if (addr->ss_family == AF_INET &&
  66 -                   (addr4->sin_addr.s_addr !=
  67 -                    server->addr.sockAddr.sin_addr.s_addr))
  68 -                       continue;
  69 -               else if (addr->ss_family == AF_INET6 &&
  70 -                        memcmp(&server->addr.sockAddr6.sin6_addr,
  71 -                               &addr6->sin6_addr, sizeof(addr6->sin6_addr)))
  72 -                       continue;
  73 +               switch (addr->ss_family) {
  74 +               case AF_INET:
  75 +                       if (addr4->sin_addr.s_addr ==
  76 +                           server->addr.sockAddr.sin_addr.s_addr) {
  77 +                               addr4->sin_port = htons(port);
  78 +                               /* user overrode default port? */
  79 +                               if (addr4->sin_port) {
  80 +                                       if (addr4->sin_port !=
  81 +                                           server->addr.sockAddr.sin_port)
  82 +                                               continue;
  83 +                               }
  84 +                               break;
  85 +                       } else
  86 +                               continue;
  87 +
  88 +               case AF_INET6:
  89 +                       if (ipv6_addr_equal(&addr6->sin6_addr,
  90 +                           &server->addr.sockAddr6.sin6_addr) &&
  91 +                           (addr6->sin6_scope_id ==
  92 +                           server->addr.sockAddr6.sin6_scope_id)) {
  93 +                               addr6->sin6_port = htons(port);
  94 +                               /* user overrode default port? */
  95 +                               if (addr6->sin6_port) {
  96 +                                       if (addr6->sin6_port !=
  97 +                                          server->addr.sockAddr6.sin6_port)
  98 +                                               continue;
  99 +                               }
 100 +                               break;
 101 +                       } else
 102 +                               continue;
 103 +               }
 104
 105                 ++server->srv_count;
 106                 write_unlock(&cifs_tcp_ses_lock);
 107 @@ -2111,7 +2135,7 @@ cifs_mount(struct super_block *sb, struc
 108                 }
 109         }
 110
 111 -       srvTcp = cifs_find_tcp_session(&addr);
 112 +       srvTcp = cifs_find_tcp_session(&addr, volume_info.port);
 113         if (!srvTcp) { /* create socket */
 114                 if (addr.ss_family == AF_INET6) {
 115                         cFYI(1, ("attempting ipv6 connect"));