From: Ilya Maximets Date: Mon, 26 Feb 2018 08:39:00 +0000 (+0100) Subject: vhost: add note about sockets in server mode X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=1cf62d96850b54a96d20ac173229814292fedb9f;p=dpdk.git vhost: add note about sockets in server mode From time to time, someone sends patches about unlinking existing sockets when registering a vhost user in server mode. A recent example: http://dpdk.org/ml/archives/dev/2018-February/090025.html This problem has been discussed many times, and it was made clear that the library should not unlink files given by the application in order to avoid possible security problems, such as removing random files used by other programs. One of the first discussions: http://dpdk.org/ml/archives/dev/2015-December/030326.html To avoid such patches in the future, it was decided to add a comment that explains what is happening and tries to describe the reasoning. Signed-off-by: Ilya Maximets Reviewed-by: Maxime Coquelin --- diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c index 6ba60f5dcd..cfc31e1797 100644 --- a/lib/librte_vhost/socket.c +++ b/lib/librte_vhost/socket.c @@ -329,6 +329,16 @@ vhost_user_start_server(struct vhost_user_socket *vsocket) int fd = vsocket->socket_fd; const char *path = vsocket->path; + /* + * bind () may fail if the socket file with the same name already + * exists. But the library obviously should not delete the file + * provided by the user, since we can not be sure that it is not + * being used by other applications. Moreover, many applications form + * socket names based on user input, which is prone to errors. + * + * The user must ensure that the socket does not exist before + * registering the vhost driver in server mode. + */ ret = bind(fd, (struct sockaddr *)&vsocket->un, sizeof(vsocket->un)); if (ret < 0) { RTE_LOG(ERR, VHOST_CONFIG,