Re: [PATCH for-9.1 6/9] block/nbd: Use URI parsing code from glib

["Richard W.M. Jones" <rjones@redhat.com>]

On Thu, Mar 28, 2024 at 02:13:42PM +0000, Richard W.M. Jones wrote:
> On Thu, Mar 28, 2024 at 03:06:03PM +0100, Thomas Huth wrote:
> > Since version 2.66, glib has useful URI parsing functions, too.
> > Use those instead of the QEMU-internal ones to be finally able
> > to get rid of the latter. The g_uri_get_host() also takes care
> > of removing the square brackets from IPv6 addresses, so we can
> > drop that part of the QEMU code now, too.
> > 
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >  block/nbd.c | 66 ++++++++++++++++++++++++++++++-----------------------
> >  1 file changed, 38 insertions(+), 28 deletions(-)
> > 
> > diff --git a/block/nbd.c b/block/nbd.c
> > index ef05f7cdfd..95b507f872 100644
> > --- a/block/nbd.c
> > +++ b/block/nbd.c
> > @@ -31,7 +31,6 @@
> >  #include "qemu/osdep.h"
> >  
> >  #include "trace.h"
> > -#include "qemu/uri.h"
> >  #include "qemu/option.h"
> >  #include "qemu/cutils.h"
> >  #include "qemu/main-loop.h"
> > @@ -1514,30 +1513,34 @@ static void nbd_client_close(BlockDriverState *bs)
> >  
> >  static int nbd_parse_uri(const char *filename, QDict *options)
> >  {
> > -    URI *uri;
> > +    GUri *uri;
> >      const char *p;
> > -    QueryParams *qp = NULL;
> > +    GHashTable *qp = NULL;
> > +    int qp_n;
> >      int ret = 0;
> >      bool is_unix;
> > +    const char *uri_scheme, *uri_query, *uri_server;
> > +    int uri_port;
> >  
> > -    uri = uri_parse(filename);
> > +    uri = g_uri_parse(filename, G_URI_FLAGS_NONE, NULL);
> >      if (!uri) {
> >          return -EINVAL;
> >      }
> >  
> >      /* transport */
> > -    if (!g_strcmp0(uri->scheme, "nbd")) {
> > +    uri_scheme = g_uri_get_scheme(uri);
> > +    if (!g_strcmp0(uri_scheme, "nbd")) {
> >          is_unix = false;
> > -    } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) {
> > +    } else if (!g_strcmp0(uri_scheme, "nbd+tcp")) {
> >          is_unix = false;
> > -    } else if (!g_strcmp0(uri->scheme, "nbd+unix")) {
> > +    } else if (!g_strcmp0(uri_scheme, "nbd+unix")) {
> >          is_unix = true;
> >      } else {
> >          ret = -EINVAL;
> >          goto out;
> >      }
> >  
> > -    p = uri->path ? uri->path : "";
> > +    p = g_uri_get_path(uri) ?: "";
> >      if (p[0] == '/') {
> >          p++;
> >      }
> > @@ -1545,51 +1548,58 @@ static int nbd_parse_uri(const char *filename, QDict *options)
> >          qdict_put_str(options, "export", p);
> >      }
> >  
> > -    qp = query_params_parse(uri->query);
> > -    if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
> > -        ret = -EINVAL;
> > -        goto out;
> > +    uri_query = g_uri_get_query(uri);
> > +    if (uri_query) {
> > +        qp = g_uri_parse_params(uri_query, -1, "&", G_URI_PARAMS_NONE, NULL);
> > +        if (!qp) {
> > +            ret = -EINVAL;
> > +            goto out;
> > +        }
> > +        qp_n = g_hash_table_size(qp);
> > +        if (qp_n > 1 || (is_unix && !qp_n) || (!is_unix && qp_n)) {
> > +            ret = -EINVAL;
> > +            goto out;
> > +        }
> > +     }
> > +
> > +    uri_server = g_uri_get_host(uri);
> > +    if (uri_server && !uri_server[0]) {
> > +        uri_server = NULL;
> >      }
> > +    uri_port = g_uri_get_port(uri);
> >  
> >      if (is_unix) {
> >          /* nbd+unix:///export?socket=path */
> > -        if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) {
> > +        const char *uri_socket = g_hash_table_lookup(qp, "socket");
> > +        if (uri_server || uri_port != -1 || !uri_socket) {
> >              ret = -EINVAL;
> >              goto out;
> >          }
> >          qdict_put_str(options, "server.type", "unix");
> > -        qdict_put_str(options, "server.path", qp->p[0].value);
> > +        qdict_put_str(options, "server.path", uri_socket);
> >      } else {
> > -        QString *host;
> >          char *port_str;
> >  
> >          /* nbd[+tcp]://host[:port]/export */
> > -        if (!uri->server) {
> > +        if (!uri_server) {
> >              ret = -EINVAL;
> >              goto out;
> >          }
> >  
> > -        /* strip braces from literal IPv6 address */
> > -        if (uri->server[0] == '[') {
> > -            host = qstring_from_substr(uri->server, 1,
> > -                                       strlen(uri->server) - 1);
> > -        } else {
> > -            host = qstring_from_str(uri->server);
> > -        }
> > -
> >          qdict_put_str(options, "server.type", "inet");
> > -        qdict_put(options, "server.host", host);
> > +        qdict_put_str(options, "server.host", uri_server);
> >  
> > -        port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT);
> > +        port_str = g_strdup_printf("%d", uri_port != -1 ? uri_port
> > +                                                        : NBD_DEFAULT_PORT);
> >          qdict_put_str(options, "server.port", port_str);
> >          g_free(port_str);
> >      }
> >  
> >  out:
> >      if (qp) {
> > -        query_params_free(qp);
> > +        g_hash_table_destroy(qp);
> >      }
> > -    uri_free(uri);
> > +    g_uri_unref(uri);
> >      return ret;
> >  }
> 
> Looks ok,
>
> Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

Or maybe not.  This caused a regression in the nbdkit test suite (when
we use qemu-img from 9.1).  It seems the exportname part of the NBD
URI gets munged:

https://gitlab.com/qemu-project/qemu/-/issues/2584

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html