ivshmem: use little-endian int64_t for the protocol

The current ivshmem protocol uses 'long' for integers. But the
sizeof(long) depends on the host and the endianess is not defined, which
may cause portability troubles.

Instead, switch to using little-endian int64_t. This breaks the
protocol, except on x64 little-endian host where this change
should be compatible.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>

3 files changed, 21 insertions, 19 deletions

diff --git a/contrib/ivshmem-client/ivshmem-client.c b/contrib/ivshmem-client/ivshmem-client.c
index 076e3ec31c..31619d80e9 100644
--- a/contrib/ivshmem-client/ivshmem-client.c
+++ b/contrib/ivshmem-client/ivshmem-client.c
@@ -24,7 +24,7 @@
 
 /* read message from the unix socket */
 static int
-ivshmem_client_read_one_msg(IvshmemClient *client, long *index, int *fd)
+ivshmem_client_read_one_msg(IvshmemClient *client, int64_t *index, int *fd)
 {
     int ret;
     struct msghdr msg;
@@ -45,7 +45,7 @@ ivshmem_client_read_one_msg(IvshmemClient *client, long *index, int *fd)
     msg.msg_controllen = sizeof(msg_control);
 
     ret = recvmsg(client->sock_fd, &msg, 0);
-    if (ret < 0) {
+    if (ret < sizeof(*index)) {
         IVSHMEM_CLIENT_DEBUG(client, "cannot read message: %s\n",
                              strerror(errno));
         return -1;
@@ -55,6 +55,7 @@ ivshmem_client_read_one_msg(IvshmemClient *client, long *index, int *fd)
         return -1;
     }
 
+    *index = GINT64_FROM_LE(*index);
     *fd = -1;
 
     for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
@@ -91,7 +92,7 @@ static int
 ivshmem_client_handle_server_msg(IvshmemClient *client)
 {
     IvshmemClientPeer *peer;
-    long peer_id;
+    int64_t peer_id;
     int ret, fd;
 
     ret = ivshmem_client_read_one_msg(client, &peer_id, &fd);
@@ -107,11 +108,11 @@ ivshmem_client_handle_server_msg(IvshmemClient *client)
 
         if (peer == NULL || peer == &client->local) {
             IVSHMEM_CLIENT_DEBUG(client, "receive delete for invalid "
-                                 "peer %ld\n", peer_id);
+                                 "peer %" PRId64 "\n", peer_id);
             return -1;
         }
 
-        IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %ld\n", peer_id);
+        IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %" PRId64 "\n", peer_id);
         ivshmem_client_free_peer(client, peer);
         return 0;
     }
@@ -122,12 +123,12 @@ ivshmem_client_handle_server_msg(IvshmemClient *client)
         peer->id = peer_id;
         peer->vectors_count = 0;
         QTAILQ_INSERT_TAIL(&client->peer_list, peer, next);
-        IVSHMEM_CLIENT_DEBUG(client, "new peer id = %ld\n", peer_id);
+        IVSHMEM_CLIENT_DEBUG(client, "new peer id = %" PRId64 "\n", peer_id);
     }
 
     /* new vector */
-    IVSHMEM_CLIENT_DEBUG(client, "  new vector %d (fd=%d) for peer id %ld\n",
-                         peer->vectors_count, fd, peer->id);
+    IVSHMEM_CLIENT_DEBUG(client, "  new vector %d (fd=%d) for peer id %"
+                         PRId64 "\n", peer->vectors_count, fd, peer->id);
     if (peer->vectors_count >= G_N_ELEMENTS(peer->vectors)) {
         IVSHMEM_CLIENT_DEBUG(client, "Too many vectors received, failing");
         return -1;
@@ -180,7 +181,7 @@ ivshmem_client_connect(IvshmemClient *client)
 {
     struct sockaddr_un sun;
     int fd, ret;
-    long tmp;
+    int64_t tmp;
 
     IVSHMEM_CLIENT_DEBUG(client, "connect to client %s\n",
                          client->unix_sock_path);
@@ -219,7 +220,7 @@ ivshmem_client_connect(IvshmemClient *client)
         IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n");
         goto err_close;
     }
-    IVSHMEM_CLIENT_DEBUG(client, "our_id=%ld\n", client->local.id);
+    IVSHMEM_CLIENT_DEBUG(client, "our_id=%" PRId64 "\n", client->local.id);
 
     /* now, we expect shared mem fd + a -1 index, note that shm fd
      * is not used */
@@ -350,13 +351,13 @@ ivshmem_client_notify(const IvshmemClient *client,
     int fd;
 
     if (vector >= peer->vectors_count) {
-        IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %ld\n",
+        IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %" PRId64 "\n",
                              vector, peer->id);
         return -1;
     }
     fd = peer->vectors[vector];
-    IVSHMEM_CLIENT_DEBUG(client, "notify peer %ld on vector %d, fd %d\n",
-                         peer->id, vector, fd);
+    IVSHMEM_CLIENT_DEBUG(client, "notify peer %" PRId64
+                         " on vector %d, fd %d\n", peer->id, vector, fd);
 
     kick = 1;
     if (write(fd, &kick, sizeof(kick)) != sizeof(kick)) {
@@ -402,7 +403,7 @@ ivshmem_client_notify_broadcast(const IvshmemClient *client)
 
 /* lookup peer from its id */
 IvshmemClientPeer *
-ivshmem_client_search_peer(IvshmemClient *client, long peer_id)
+ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id)
 {
     IvshmemClientPeer *peer;
 
@@ -427,7 +428,7 @@ ivshmem_client_dump(const IvshmemClient *client)
 
     /* dump local infos */
     peer = &client->local;
-    printf("our_id = %ld\n", peer->id);
+    printf("our_id = %" PRId64 "\n", peer->id);
     for (vector = 0; vector < peer->vectors_count; vector++) {
         printf("  vector %d is enabled (fd=%d)\n", vector,
                peer->vectors[vector]);
@@ -435,7 +436,7 @@ ivshmem_client_dump(const IvshmemClient *client)
 
     /* dump peers */
     QTAILQ_FOREACH(peer, &client->peer_list, next) {
-        printf("peer_id = %ld\n", peer->id);
+        printf("peer_id = %" PRId64 "\n", peer->id);
 
         for (vector = 0; vector < peer->vectors_count; vector++) {
             printf("  vector %d is enabled (fd=%d)\n", vector,
diff --git a/contrib/ivshmem-client/ivshmem-client.h b/contrib/ivshmem-client/ivshmem-client.h
index 9215f3420e..3a4f809682 100644
--- a/contrib/ivshmem-client/ivshmem-client.h
+++ b/contrib/ivshmem-client/ivshmem-client.h
@@ -43,7 +43,7 @@
  */
 typedef struct IvshmemClientPeer {
     QTAILQ_ENTRY(IvshmemClientPeer) next;    /**< next in list*/
-    long id;                                 /**< the id of the peer */
+    int64_t id;                              /**< the id of the peer */
     int vectors[IVSHMEM_CLIENT_MAX_VECTORS]; /**< one fd per vector */
     unsigned vectors_count;                  /**< number of vectors */
 } IvshmemClientPeer;
@@ -198,7 +198,7 @@ int ivshmem_client_notify_broadcast(const IvshmemClient *client);
  * Returns:  The peer structure, or NULL if not found
  */
 IvshmemClientPeer *
-ivshmem_client_search_peer(IvshmemClient *client, long peer_id);
+ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id);
 
 /**
  * Dump information of this ivshmem client on stdout
diff --git a/contrib/ivshmem-client/main.c b/contrib/ivshmem-client/main.c
index 28dd81e5a1..c004870ae3 100644
--- a/contrib/ivshmem-client/main.c
+++ b/contrib/ivshmem-client/main.c
@@ -179,7 +179,8 @@ ivshmem_client_notification_cb(const IvshmemClient *client,
 {
     (void)client;
     (void)arg;
-    printf("receive notification from peer_id=%ld vector=%d\n", peer->id, vect);
+    printf("receive notification from peer_id=%" PRId64 " vector=%u\n",
+           peer->id, vect);
 }
 
 int