| Message ID | 4A8BC92B.70302@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 19 Aug 2009 15:13:07 +0530 Suresh Jayaraman <sjayaraman@suse.de> wrote: > Just noticed that there was a undesired fall-through bug with the > previous version of the patch. Fixed it. > > It seems there is a regression that got introduced while Jeff fixed > all the mount/umount races. While attempting to find whether a tcp > session is already existing, we were not checking whether the "port" > used are the same. When a second mount is attempted with a different > "port=" option, it is being ignored. Because of this the cifs mounts > that uses a SSH tunnel appears to be broken. > > Steps to reproduce: > > 1. create 2 shares > # SSH Tunnel a SMB session > 2. ssh -f -L 6111:127.0.0.1:445 root@localhost "sleep 86400" > 3. ssh -f -L 6222:127.0.0.1:445 root@localhost "sleep 86400" > 4. tcpdump -i lo 6111 & > 5. mkdir -p /mnt/mnt1 > 6. mkdir -p /mnt/mnt2 > 7. mount.cifs //localhost/a /mnt/mnt1 -o username=guest,ip=127.0.0.1,port=6111 > #(shows tcpdump activity on port 6111) > 8. mount.cifs //localhost/b /mnt/mnt2 -o username=guest,ip=127.0.0.1,port=6222 > #(shows tcpdump activity only on port 6111 and not on 6222 > > Fix by adding a check to compare the port _only_ if the user tries to > override the tcp port with "port=" option, before deciding that an > existing tcp session is found. Also, clean up a bit by replacing > if-else if by a switch statment while at it as suggested by Jeff. > > Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de> > --- > > fs/cifs/connect.c | 57 +++++++++++++++++++++++++++++++++++++++++----------- > 1 files changed, 45 insertions(+), 12 deletions(-) > A couple of minor comments below. In general, I find it better to structure the code so that you end up with less indentation, and unneeded else clauses, etc... > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 1f3345d..bfc5fa9 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -1377,7 +1377,7 @@ cifs_parse_mount_options(char *options, const char *devname, > } > > static struct TCP_Server_Info * > -cifs_find_tcp_session(struct sockaddr_storage *addr) > +cifs_find_tcp_session(struct sockaddr_storage *addr, unsigned short int port) > { > struct list_head *tmp; > struct TCP_Server_Info *server; > @@ -1397,16 +1397,49 @@ cifs_find_tcp_session(struct sockaddr_storage *addr) > if (server->tcpStatus == CifsNew) > continue; > > - if (addr->ss_family == AF_INET && > - (addr4->sin_addr.s_addr != > - server->addr.sockAddr.sin_addr.s_addr)) > - continue; > - else if (addr->ss_family == AF_INET6 && > - (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, > - &addr6->sin6_addr) || > - server->addr.sockAddr6.sin6_scope_id != > - addr6->sin6_scope_id)) > - continue; > + switch (addr->ss_family) { > + case AF_INET: > + /* user overrode default port? */ > + if (port) { ^^^^ this is rather awkward since you now have 2 copies of each address comparison per family. If you compare the address before checking for the port then this function will be slightly more efficient and will look cleaner. > + addr4->sin_port = htons(port); > + if (addr4->sin_addr.s_addr != > + server->addr.sockAddr.sin_addr.s_addr || > + addr4->sin_port != > + server->addr.sockAddr.sin_port) > + continue; > + else > + break; ^^^ no need for the else's here, just move the break outside of the outer "if's". > + } else { > + if (addr4->sin_addr.s_addr != > + server->addr.sockAddr.sin_addr.s_addr) > + continue; > + else > + break; > + } > + > + case AF_INET6: > + /* user overrode default port? */ > + if (port) { > + addr6->sin6_port = htons(port); > + if (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, > + &addr6->sin6_addr) || > + server->addr.sockAddr6.sin6_scope_id != > + addr6->sin6_scope_id || > + server->addr.sockAddr6.sin6_port != > + addr6->sin6_port) > + continue; > + else > + break; > + } else { > + if (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, > + &addr6->sin6_addr) || > + server->addr.sockAddr6.sin6_scope_id != > + addr6->sin6_scope_id) > + continue; > + else > + break; > + } > + } The same comments apply to the IPv6 stanza here too. > > ++server->srv_count; > write_unlock(&cifs_tcp_ses_lock); > @@ -1475,7 +1508,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info) > } > > /* see if we already have a matching tcp_ses */ > - tcp_ses = cifs_find_tcp_session(&addr); > + tcp_ses = cifs_find_tcp_session(&addr, volume_info->port); > if (tcp_ses) > return tcp_ses; >
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 1f3345d..bfc5fa9 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1377,7 +1377,7 @@ cifs_parse_mount_options(char *options, const char *devname, } static struct TCP_Server_Info * -cifs_find_tcp_session(struct sockaddr_storage *addr) +cifs_find_tcp_session(struct sockaddr_storage *addr, unsigned short int port) { struct list_head *tmp; struct TCP_Server_Info *server; @@ -1397,16 +1397,49 @@ cifs_find_tcp_session(struct sockaddr_storage *addr) if (server->tcpStatus == CifsNew) continue; - if (addr->ss_family == AF_INET && - (addr4->sin_addr.s_addr != - server->addr.sockAddr.sin_addr.s_addr)) - continue; - else if (addr->ss_family == AF_INET6 && - (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, - &addr6->sin6_addr) || - server->addr.sockAddr6.sin6_scope_id != - addr6->sin6_scope_id)) - continue; + switch (addr->ss_family) { + case AF_INET: + /* user overrode default port? */ + if (port) { + addr4->sin_port = htons(port); + if (addr4->sin_addr.s_addr != + server->addr.sockAddr.sin_addr.s_addr || + addr4->sin_port != + server->addr.sockAddr.sin_port) + continue; + else + break; + } else { + if (addr4->sin_addr.s_addr != + server->addr.sockAddr.sin_addr.s_addr) + continue; + else + break; + } + + case AF_INET6: + /* user overrode default port? */ + if (port) { + addr6->sin6_port = htons(port); + if (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, + &addr6->sin6_addr) || + server->addr.sockAddr6.sin6_scope_id != + addr6->sin6_scope_id || + server->addr.sockAddr6.sin6_port != + addr6->sin6_port) + continue; + else + break; + } else { + if (!ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr, + &addr6->sin6_addr) || + server->addr.sockAddr6.sin6_scope_id != + addr6->sin6_scope_id) + continue; + else + break; + } + } ++server->srv_count; write_unlock(&cifs_tcp_ses_lock); @@ -1475,7 +1508,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info) } /* see if we already have a matching tcp_ses */ - tcp_ses = cifs_find_tcp_session(&addr); + tcp_ses = cifs_find_tcp_session(&addr, volume_info->port); if (tcp_ses) return tcp_ses;
Just noticed that there was a undesired fall-through bug with the previous version of the patch. Fixed it. It seems there is a regression that got introduced while Jeff fixed all the mount/umount races. While attempting to find whether a tcp session is already existing, we were not checking whether the "port" used are the same. When a second mount is attempted with a different "port=" option, it is being ignored. Because of this the cifs mounts that uses a SSH tunnel appears to be broken. Steps to reproduce: 1. create 2 shares # SSH Tunnel a SMB session 2. ssh -f -L 6111:127.0.0.1:445 root@localhost "sleep 86400" 3. ssh -f -L 6222:127.0.0.1:445 root@localhost "sleep 86400" 4. tcpdump -i lo 6111 & 5. mkdir -p /mnt/mnt1 6. mkdir -p /mnt/mnt2 7. mount.cifs //localhost/a /mnt/mnt1 -o username=guest,ip=127.0.0.1,port=6111 #(shows tcpdump activity on port 6111) 8. mount.cifs //localhost/b /mnt/mnt2 -o username=guest,ip=127.0.0.1,port=6222 #(shows tcpdump activity only on port 6111 and not on 6222 Fix by adding a check to compare the port _only_ if the user tries to override the tcp port with "port=" option, before deciding that an existing tcp session is found. Also, clean up a bit by replacing if-else if by a switch statment while at it as suggested by Jeff. Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de> --- fs/cifs/connect.c | 57 +++++++++++++++++++++++++++++++++++++++++----------- 1 files changed, 45 insertions(+), 12 deletions(-)