libceph: message signature support

Signed-off-by: Yan, Zheng <zyan@redhat.com>

8 files changed, 162 insertions, 4 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index fc74617069a3..9f00853f6d42 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3744,6 +3744,20 @@ static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
         return msg;
 }
 
+static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
+{
+       struct ceph_mds_session *s = con->private;
+       struct ceph_auth_handshake *auth = &s->s_auth;
+       return ceph_auth_sign_message(auth, msg);
+}
+
+static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
+{
+       struct ceph_mds_session *s = con->private;
+       struct ceph_auth_handshake *auth = &s->s_auth;
+       return ceph_auth_check_message_signature(auth, msg);
+}
+
 static const struct ceph_connection_operations mds_con_ops = {
         .get = con_get,
         .put = con_put,
@@ -3753,6 +3767,8 @@ static const struct ceph_connection_operations mds_con_ops = {
         .invalidate_authorizer = invalidate_authorizer,
         .peer_reset = peer_reset,
         .alloc_msg = mds_alloc_msg,
+        .sign_message = sign_message,
+        .check_message_signature = check_message_signature,
 };
 
 /* eof */
diff --git a/include/linux/ceph/auth.h b/include/linux/ceph/auth.h
index 5f3386844134..260d78b587c4 100644
--- a/include/linux/ceph/auth.h
+++ b/include/linux/ceph/auth.h
@@ -13,6 +13,7 @@
 
 struct ceph_auth_client;
 struct ceph_authorizer;
+struct ceph_msg;
 
 struct ceph_auth_handshake {
         struct ceph_authorizer *authorizer;
@@ -20,6 +21,10 @@ struct ceph_auth_handshake {
         size_t authorizer_buf_len;
         void *authorizer_reply_buf;
         size_t authorizer_reply_buf_len;
+        int (*sign_message)(struct ceph_auth_handshake *auth,
+                            struct ceph_msg *msg);
+        int (*check_message_signature)(struct ceph_auth_handshake *auth,
+                                       struct ceph_msg *msg);
 };
 
 struct ceph_auth_client_ops {
@@ -66,6 +71,11 @@ struct ceph_auth_client_ops {
         void (*reset)(struct ceph_auth_client *ac);
 
         void (*destroy)(struct ceph_auth_client *ac);
+
+        int (*sign_message)(struct ceph_auth_handshake *auth,
+                            struct ceph_msg *msg);
+        int (*check_message_signature)(struct ceph_auth_handshake *auth,
+                                       struct ceph_msg *msg);
 };
 
 struct ceph_auth_client {
@@ -113,4 +123,20 @@ extern int ceph_auth_verify_authorizer_reply(struct ceph_auth_client *ac,
 extern void ceph_auth_invalidate_authorizer(struct ceph_auth_client *ac,
                                             int peer_type);
 
+static inline int ceph_auth_sign_message(struct ceph_auth_handshake *auth,
+                                         struct ceph_msg *msg)
+{
+        if (auth->sign_message)
+                return auth->sign_message(auth, msg);
+        return 0;
+}
+
+static inline
+int ceph_auth_check_message_signature(struct ceph_auth_handshake *auth,
+                                      struct ceph_msg *msg)
+{
+        if (auth->check_message_signature)
+                return auth->check_message_signature(auth, msg);
+        return 0;
+}
 #endif
diff --git a/include/linux/ceph/ceph_features.h b/include/linux/ceph/ceph_features.h
index d12659ce550d..71e05bbf8ceb 100644
--- a/include/linux/ceph/ceph_features.h
+++ b/include/linux/ceph/ceph_features.h
@@ -84,6 +84,7 @@ static inline u64 ceph_sanitize_features(u64 features)
          CEPH_FEATURE_PGPOOL3 |                 \
          CEPH_FEATURE_OSDENC |                  \
          CEPH_FEATURE_CRUSH_TUNABLES |          \
+         CEPH_FEATURE_MSG_AUTH |                \
          CEPH_FEATURE_CRUSH_TUNABLES2 |         \
          CEPH_FEATURE_REPLY_CREATE_INODE |      \
          CEPH_FEATURE_OSDHASHPSPOOL |           \
diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h
index 40ae58e3e9db..d9d396c16503 100644
--- a/include/linux/ceph/messenger.h
+++ b/include/linux/ceph/messenger.h
@@ -42,6 +42,10 @@ struct ceph_connection_operations {
         struct ceph_msg * (*alloc_msg) (struct ceph_connection *con,
                                         struct ceph_msg_header *hdr,
                                         int *skip);
+        int (*sign_message) (struct ceph_connection *con, struct ceph_msg *msg);
+
+        int (*check_message_signature) (struct ceph_connection *con,
+                                        struct ceph_msg *msg);
 };
 
 /* use format string %s%d */
@@ -142,7 +146,10 @@ struct ceph_msg_data_cursor {
  */
 struct ceph_msg {
         struct ceph_msg_header hdr;     /* header */
-        struct ceph_msg_footer footer;  /* footer */
+        union {
+                struct ceph_msg_footer footer;          /* footer */
+                struct ceph_msg_footer_old old_footer;  /* old format footer */
+        };
         struct kvec front;              /* unaligned blobs of message */
         struct ceph_buffer *middle;
 
diff --git a/include/linux/ceph/msgr.h b/include/linux/ceph/msgr.h
index 3d94a73b5f30..cac4b28ac1c0 100644
--- a/include/linux/ceph/msgr.h
+++ b/include/linux/ceph/msgr.h
@@ -164,13 +164,21 @@ struct ceph_msg_header {
 /*
  * follows data payload
  */
+struct ceph_msg_footer_old {
+        __le32 front_crc, middle_crc, data_crc;
+        __u8 flags;
+} __attribute__ ((packed));
+
 struct ceph_msg_footer {
         __le32 front_crc, middle_crc, data_crc;
+        // sig holds the 64 bits of the digital signature for the message PLR
+        __le64  sig;
         __u8 flags;
 } __attribute__ ((packed));
 
 #define CEPH_MSG_FOOTER_COMPLETE  (1<<0)   /* msg wasn't aborted */
 #define CEPH_MSG_FOOTER_NOCRC     (1<<1)   /* no data crc */
+#define CEPH_MSG_FOOTER_SIGNED    (1<<2)   /* msg was signed */
 
 
 #endif
diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c
index 77f3885c16bc..15845814a0f2 100644
--- a/net/ceph/auth_x.c
+++ b/net/ceph/auth_x.c
@@ -8,6 +8,7 @@
 
 #include <linux/ceph/decode.h>
 #include <linux/ceph/auth.h>
+#include <linux/ceph/messenger.h>
 
 #include "crypto.h"
 #include "auth_x.h"
@@ -567,6 +568,8 @@ static int ceph_x_create_authorizer(
         auth->authorizer_buf_len = au->buf->vec.iov_len;
         auth->authorizer_reply_buf = au->reply_buf;
         auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
+        auth->sign_message = ac->ops->sign_message;
+        auth->check_message_signature = ac->ops->check_message_signature;
 
         return 0;
 }
@@ -667,6 +670,59 @@ static void ceph_x_invalidate_authorizer(struct ceph_auth_client *ac,
                 memset(&th->validity, 0, sizeof(th->validity));
 }
 
+static int calcu_signature(struct ceph_x_authorizer *au,
+                           struct ceph_msg *msg, __le64 *sig)
+{
+        int ret;
+        char tmp_enc[40];
+        __le32 tmp[5] = {
+                16u, msg->hdr.crc, msg->footer.front_crc,
+                msg->footer.middle_crc, msg->footer.data_crc,
+        };
+        ret = ceph_x_encrypt(&au->session_key, &tmp, sizeof(tmp),
+                             tmp_enc, sizeof(tmp_enc));
+        if (ret < 0)
+                return ret;
+        *sig = *(__le64*)(tmp_enc + 4);
+        return 0;
+}
+
+static int ceph_x_sign_message(struct ceph_auth_handshake *auth,
+                               struct ceph_msg *msg)
+{
+        int ret;
+        if (!auth->authorizer)
+                return 0;
+        ret = calcu_signature((struct ceph_x_authorizer *)auth->authorizer,
+                              msg, &msg->footer.sig);
+        if (ret < 0)
+                return ret;
+        msg->footer.flags |= CEPH_MSG_FOOTER_SIGNED;
+        return 0;
+}
+
+static int ceph_x_check_message_signature(struct ceph_auth_handshake *auth,
+                                          struct ceph_msg *msg)
+{
+        __le64 sig_check;
+        int ret;
+
+        if (!auth->authorizer)
+                return 0;
+        ret = calcu_signature((struct ceph_x_authorizer *)auth->authorizer,
+                              msg, &sig_check);
+        if (ret < 0)
+                return ret;
+        if (sig_check == msg->footer.sig)
+                return 0;
+        if (msg->footer.flags & CEPH_MSG_FOOTER_SIGNED)
+                dout("ceph_x_check_message_signature %p has signature %llx "
+                     "expect %llx\n", msg, msg->footer.sig, sig_check);
+        else
+                dout("ceph_x_check_message_signature %p sender did not set "
+                     "CEPH_MSG_FOOTER_SIGNED\n", msg);
+        return -EBADMSG;
+}
 
 static const struct ceph_auth_client_ops ceph_x_ops = {
         .name = "x",
@@ -681,6 +737,8 @@ static const struct ceph_auth_client_ops ceph_x_ops = {
         .invalidate_authorizer = ceph_x_invalidate_authorizer,
         .reset =  ceph_x_reset,
         .destroy = ceph_x_destroy,
+        .sign_message = ceph_x_sign_message,
+        .check_message_signature = ceph_x_check_message_signature,
 };
 
 
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 863d07ab2129..33a2f201e460 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1196,8 +1196,18 @@ static void prepare_write_message_footer(struct ceph_connection *con)
         dout("prepare_write_message_footer %p\n", con);
         con->out_kvec_is_msg = true;
         con->out_kvec[v].iov_base = &m->footer;
-        con->out_kvec[v].iov_len = sizeof(m->footer);
-        con->out_kvec_bytes += sizeof(m->footer);
+        if (con->peer_features & CEPH_FEATURE_MSG_AUTH) {
+                if (con->ops->sign_message)
+                        con->ops->sign_message(con, m);
+                else
+                        m->footer.sig = 0;
+                con->out_kvec[v].iov_len = sizeof(m->footer);
+                con->out_kvec_bytes += sizeof(m->footer);
+        } else {
+                m->old_footer.flags = m->footer.flags;
+                con->out_kvec[v].iov_len = sizeof(m->old_footer);
+                con->out_kvec_bytes += sizeof(m->old_footer);
+        }
         con->out_kvec_left++;
         con->out_more = m->more_to_follow;
         con->out_msg_done = true;
@@ -2249,6 +2259,7 @@ static int read_partial_message(struct ceph_connection *con)
         int ret;
         unsigned int front_len, middle_len, data_len;
         bool do_datacrc = !con->msgr->nocrc;
+        bool need_sign = (con->peer_features & CEPH_FEATURE_MSG_AUTH);
         u64 seq;
         u32 crc;
 
@@ -2361,12 +2372,21 @@ static int read_partial_message(struct ceph_connection *con)
         }
 
         /* footer */
-        size = sizeof (m->footer);
+        if (need_sign)
+                size = sizeof(m->footer);
+        else
+                size = sizeof(m->old_footer);
+
         end += size;
         ret = read_partial(con, end, size, &m->footer);
         if (ret <= 0)
                 return ret;
 
+        if (!need_sign) {
+                m->footer.flags = m->old_footer.flags;
+                m->footer.sig = 0;
+        }
+
         dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
              m, front_len, m->footer.front_crc, middle_len,
              m->footer.middle_crc, data_len, m->footer.data_crc);
@@ -2390,6 +2410,12 @@ static int read_partial_message(struct ceph_connection *con)
                 return -EBADMSG;
         }
 
+        if (need_sign && con->ops->check_message_signature &&
+            con->ops->check_message_signature(con, m)) {
+                pr_err("read_partial_message %p signature check failed\n", m);
+                return -EBADMSG;
+        }
+
         return 1; /* done! */
 }
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 6f164289bde8..1f6c4055adaf 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -2920,6 +2920,20 @@ static int invalidate_authorizer(struct ceph_connection *con)
         return ceph_monc_validate_auth(&osdc->client->monc);
 }
 
+static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
+{
+        struct ceph_osd *o = con->private;
+        struct ceph_auth_handshake *auth = &o->o_auth;
+        return ceph_auth_sign_message(auth, msg);
+}
+
+static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
+{
+        struct ceph_osd *o = con->private;
+        struct ceph_auth_handshake *auth = &o->o_auth;
+        return ceph_auth_check_message_signature(auth, msg);
+}
+
 static const struct ceph_connection_operations osd_con_ops = {
         .get = get_osd_con,
         .put = put_osd_con,
@@ -2928,5 +2942,7 @@ static const struct ceph_connection_operations osd_con_ops = {
         .verify_authorizer_reply = verify_authorizer_reply,
         .invalidate_authorizer = invalidate_authorizer,
         .alloc_msg = alloc_msg,
+        .sign_message = sign_message,
+        .check_message_signature = check_message_signature,
         .fault = osd_reset,
 };