USS : fill proper uid and gid during a access call from nfs

Problem : when an user tries to access a file/folder for which
he does not have a proper permission required then fuse gives out
a proper error "Permission denied", but nfs does not give out that
error, rather he can access the file/folder. The reason being uid and
gid of call frame stack takes a default value of uid and gid which
point to root permission.

Solution : Set a proper uid and gid during a access call from nfs

Change-Id: Ib060706fde66ec7e60f242fab1f3e59122ed2245
BUG: 1167580
Signed-off-by: Sachin Pandit <spandit@redhat.com>
Reviewed-on: http://review.gluster.org/9194
Reviewed-by: Vijaikumar Mallikarjuna <vmallika@redhat.com>
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

2 files changed, 207 insertions, 1 deletions

diff --git a/tests/bugs/bug-1167580-set-proper-uid-and-gid-during-nfs-access.t b/tests/bugs/bug-1167580-set-proper-uid-and-gid-during-nfs-access.t
new file mode 100644
index 00000000000..1eb3d55e36c
--- /dev/null
+++ b/tests/bugs/bug-1167580-set-proper-uid-and-gid-during-nfs-access.t
@@ -0,0 +1,201 @@
+#!/bin/bash
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../nfs.rc
+. $(dirname $0)/../volume.rc
+. $(dirname $0)/../snapshot.rc
+
+# This function returns a value "Y" if user can execute
+# the given command. Else it will return "N"
+# @arg-1 : Name of the user
+# @arg-2 : Path of the file
+# @arg-3 : command to be executed
+function check_if_permitted () {
+        local usr=$1
+        local path=$2
+        local cmd=$3
+        local var
+        local ret
+        var=$(su - $usr -c "$cmd $path")
+        ret=$?
+
+        if [ "$cmd" == "cat" ]
+        then
+                if [ "$var" == "Test" ]
+                then
+                        echo "Y"
+                else
+                        echo "N"
+                fi
+        else
+                if [ "$ret" == "0" ]
+                then
+                        echo "Y"
+                else
+                        echo "N"
+                fi
+        fi
+}
+
+# Create a directory in /tmp to specify which directory to make
+# as home directory for user
+home_dir=$(cat /dev/urandom | tr -dc 'a-zA-Z' | fold -w 8 | head -n 1)
+home_dir="/tmp/bug-1167580-$home_dir"
+mkdir $home_dir
+
+function get_new_user() {
+        local temp=$(cat /dev/urandom | tr -dc 'a-zA-Z' | fold -w 8 | head -n 1)
+        id $temp
+        if [ "$?" == "0" ]
+        then
+                get_new_user
+        else
+                echo $temp
+        fi
+}
+
+function create_user() {
+        local user=$1
+        local group=$2
+
+        if [ "$group" == "" ]
+        then
+                useradd -d $home_dir/$user $user
+        else
+                useradd -d $home_dir/$user -G $group $user
+        fi
+
+        return $?
+}
+
+cleanup;
+
+TEST setup_lvm 1
+TEST glusterd
+
+TEST $CLI volume create $V0 $H0:$L1
+TEST $CLI volume start $V0
+
+# Mount the volume as both fuse and nfs mount
+EXPECT_WITHIN $NFS_EXPORT_TIMEOUT "1" is_nfs_export_available
+TEST glusterfs -s $H0 --volfile-id $V0 $M0
+TEST mount_nfs $H0:/$V0 $N0 nolock
+
+# Create 2 user
+user1=$(get_new_user)
+create_user $user1
+user2=$(get_new_user)
+create_user $user2
+
+# create a file for which only user1 has access
+echo "Test" > $M0/README
+chown $user1 $M0/README
+chmod 700 $M0/README
+
+# enable uss and take a snapshot
+TEST $CLI volume set $V0 uss enable
+TEST $CLI snapshot config activate-on-create on
+TEST $CLI snapshot create snap1 $V0
+
+# try to access the file using user1 account.
+# It should succeed with both normal mount and snapshot world.
+# There is time delay in which snapd might not have got the notification
+# from glusterd about snapshot create hence using "EXPECT_WITHIN"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user1 $M0/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user1 $N0/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user1 $M0/.snaps/snap1/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user1 $N0/.snaps/snap1/README cat
+
+
+# try to access the file using user2 account
+# It should fail from both normal mount and snapshot world
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user2 $M0/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user2 $N0/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user2 $M0/.snaps/snap1/README cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user2 $N0/.snaps/snap1/README cat
+
+# We need to test another scenario where user belonging to one group
+# tries to access files from user belonging to another group
+# instead of using the already created users and making the test case look complex
+# I thought of using two different users.
+
+# The test case written below does the following things
+# 1) Create 2 users (user{3,4}), belonging to 2 different groups (group{3,4})
+# 2) Take a snapshot "snap2"
+# 3) Create a file for which only users belonging to group3 have
+# permission to read
+# 4) Test various combinations of Read-Write, Fuse-NFS mount, User{3,4,5}
+#    from both normal mount, and USS world.
+
+echo "Test" > $M0/file3
+
+chmod 740 $M0/file3
+
+group3=$(get_new_user)
+groupadd $group3
+
+group4=$(get_new_user)
+groupadd $group4
+
+user3=$(get_new_user)
+create_user $user3 $group3
+
+user4=$(get_new_user)
+create_user $user4 $group4
+
+user5=$(get_new_user)
+create_user $user5
+
+chgrp $group3 $M0/file3
+
+TEST $CLI snapshot create snap2 $V0
+
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user3 $M0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user3 $M0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user3 $M0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user3 $M0/.snaps/snap2/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user3 $N0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "Y" check_if_permitted $user3 $N0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user3 $N0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user3 $N0/.snaps/snap2/file3 "echo Hello >"
+
+
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $M0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $M0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $M0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $M0/.snaps/snap2/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $N0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $N0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $N0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user4 $N0/.snaps/snap2/file3 "echo Hello >"
+
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $M0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $M0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $M0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $M0/.snaps/snap2/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $N0/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $N0/.snaps/snap2/file3 cat
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $N0/file3 "echo Hello >"
+EXPECT_WITHIN $PROCESS_UP_TIMEOUT "N" check_if_permitted $user5 $N0/.snaps/snap2/file3 "echo Hello >"
+
+# cleanup
+/usr/sbin/userdel -f -r $user1
+/usr/sbin/userdel -f -r $user2
+/usr/sbin/userdel -f -r $user3
+/usr/sbin/userdel -f -r $user4
+/usr/sbin/userdel -f -r $user5
+
+#cleanup all the home directory which is created as part of this test case
+if [ -d "$home_dir" ]
+then
+        rm -rf $home_dir
+fi
+
+
+groupdel $group3
+groupdel $group4
+
+TEST $CLI snapshot delete all
+
+cleanup;
+
+
diff --git a/xlators/features/snapview-server/src/snapview-server.c b/xlators/features/snapview-server/src/snapview-server.c
index d66150e769a..8655bf5636c 100644
--- a/xlators/features/snapview-server/src/snapview-server.c
+++ b/xlators/features/snapview-server/src/snapview-server.c
@@ -2016,8 +2016,13 @@ svs_access (call_frame_t *frame, xlator_t *this, loc_t *loc, int mask,
            fuse and nfs. So set frame->root->pid as fspid of the syncop
            if the call came from nfs
         */
-        if (!is_fuse_call)
+        if (!is_fuse_call) {
                 syncopctx_setfspid (&frame->root->pid);
+                syncopctx_setfsuid (&frame->root->uid);
+                syncopctx_setfsgid (&frame->root->gid);
+                syncopctx_setfsgroups (frame->root->ngrps,
+                                       frame->root->groups);
+        }
 
         ret = glfs_h_access (fs, object, mask);
         if (ret < 0) {