posix/afr: handle backward compatibility for rchecksum fop

Added a volume option 'fips-mode-rchecksum' tied to op version 4.
If not set, rchecksum fop will use MD5 instead of SHA256.

updates: #230
Change-Id: Id8ea1303777e6450852c0bc25503cda341a6aec2
Signed-off-by: Ravishankar N <ravishankar@redhat.com>

3 files changed, 41 insertions, 3 deletions

diff --git a/xlators/storage/posix/src/posix-common.c b/xlators/storage/posix/src/posix-common.c
index a67b3d7dc70..f1fa81e056b 100644
--- a/xlators/storage/posix/src/posix-common.c
+++ b/xlators/storage/posix/src/posix-common.c
@@ -387,6 +387,9 @@ posix_reconfigure (xlator_t *this, dict_t *options)
 
         GF_OPTION_RECONF ("max-hardlinks", priv->max_hardlinks,
                           options, uint32, out);
+
+        GF_OPTION_RECONF ("fips-mode-rchecksum", priv->fips_mode_rchecksum,
+                          options, bool, out);
         ret = 0;
 out:
         return ret;
@@ -1076,6 +1079,9 @@ posix_init (xlator_t *this)
         _private->create_directory_mask = create_directory_mask;
 
         GF_OPTION_INIT ("max-hardlinks", _private->max_hardlinks, uint32, out);
+
+        GF_OPTION_INIT ("fips-mode-rchecksum", _private->fips_mode_rchecksum,
+                        bool, out);
 out:
         if (ret) {
                 if (_private) {
@@ -1362,5 +1368,15 @@ struct volume_options options[] = {
           .description = "max number of hardlinks allowed on any one inode.\n"
                          "0 is unlimited, 1 prevents any hardlinking at all."
         },
+        {
+          .key = {"fips-mode-rchecksum"},
+          .type = GF_OPTION_TYPE_BOOL,
+          .default_value = "off",
+          .op_version  = {GD_OP_VERSION_4_0_0},
+          .flags = OPT_FLAG_SETTABLE,
+          .tags = {"posix"},
+          .description = "If enabled, posix_rchecksum uses the FIPS compliant"
+                         "SHA256 checksum. MD5 otherwise."
+        },
         { .key  = {NULL} }
 };
diff --git a/xlators/storage/posix/src/posix-inode-fd-ops.c b/xlators/storage/posix/src/posix-inode-fd-ops.c
index 812cf792874..f3a2a7bfb83 100644
--- a/xlators/storage/posix/src/posix-inode-fd-ops.c
+++ b/xlators/storage/posix/src/posix-inode-fd-ops.c
@@ -4873,7 +4873,9 @@ posix_rchecksum (call_frame_t *frame, xlator_t *this,
         ssize_t                 bytes_read      = 0;
         int32_t                 weak_checksum   = 0;
         int32_t                 zerofillcheck   = 0;
+        unsigned char           md5_checksum[MD5_DIGEST_LENGTH] = {0};
         unsigned char           strong_checksum[SHA256_DIGEST_LENGTH] = {0};
+        unsigned char           *checksum = NULL;
         struct posix_private    *priv           = NULL;
         dict_t                  *rsp_xdata      = NULL;
         gf_boolean_t            buf_has_zeroes  = _gf_false;
@@ -4942,13 +4944,31 @@ posix_rchecksum (call_frame_t *frame, xlator_t *this,
                 }
         }
         weak_checksum = gf_rsync_weak_checksum ((unsigned char *) buf, (size_t) ret);
-        gf_rsync_strong_checksum ((unsigned char *) buf, (size_t) bytes_read,
-                                  (unsigned char *) strong_checksum);
 
+        if (priv->fips_mode_rchecksum) {
+                ret = dict_set_int32 (rsp_xdata, "fips-mode-rchecksum", 1);
+                if (ret) {
+                        gf_msg (this->name, GF_LOG_WARNING, -ret,
+                                P_MSG_DICT_SET_FAILED, "%s: Failed to set "
+                                "dictionary value for key: %s",
+                                uuid_utoa (fd->inode->gfid),
+                                "fips-mode-rchecksum");
+                        goto out;
+                }
+                checksum = strong_checksum;
+                gf_rsync_strong_checksum ((unsigned char *)buf,
+                                          (size_t) bytes_read,
+                                          (unsigned char *)checksum);
+        } else {
+                checksum = md5_checksum;
+                gf_rsync_md5_checksum ((unsigned char *)buf,
+                                       (size_t) bytes_read,
+                                       (unsigned char *)checksum);
+        }
         op_ret = 0;
 out:
         STACK_UNWIND_STRICT (rchecksum, frame, op_ret, op_errno,
-                             weak_checksum, strong_checksum, rsp_xdata);
+                             weak_checksum, checksum, rsp_xdata);
         if (rsp_xdata)
                 dict_unref (rsp_xdata);
         GF_FREE (alloc_buf);
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index 5a623aa657a..08bcb1bddae 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -243,6 +243,8 @@ struct posix_private {
         mode_t          create_mask;
         mode_t          create_directory_mask;
         uint32_t max_hardlinks;
+
+        gf_boolean_t fips_mode_rchecksum;
 };
 
 typedef struct {