Re: [PATCH v11 02/10] migration: convert migration 'uri' into 'MigrateAddress'

[Fabiano Rosas <farosas@suse.de>]

Het Gala <het.gala@nutanix.com> writes:

> This patch parses 'migrate' and 'migrate-incoming' QAPI's 'uri'
> string containing migration connection related information
> and stores them inside well defined 'MigrateAddress' struct.
>
> Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
> Signed-off-by: Het Gala <het.gala@nutanix.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  migration/exec.c      |  1 -
>  migration/exec.h      |  4 ++++
>  migration/migration.c | 55 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/migration/exec.c b/migration/exec.c
> index 2bf882bbe1..32f5143dfd 100644
> --- a/migration/exec.c
> +++ b/migration/exec.c
> @@ -27,7 +27,6 @@
>  #include "qemu/cutils.h"
>  
>  #ifdef WIN32
> -const char *exec_get_cmd_path(void);
>  const char *exec_get_cmd_path(void)
>  {
>      g_autofree char *detected_path = g_new(char, MAX_PATH);
> diff --git a/migration/exec.h b/migration/exec.h
> index b210ffde7a..736cd71028 100644
> --- a/migration/exec.h
> +++ b/migration/exec.h
> @@ -19,6 +19,10 @@
>  
>  #ifndef QEMU_MIGRATION_EXEC_H
>  #define QEMU_MIGRATION_EXEC_H
> +
> +#ifdef WIN32
> +const char *exec_get_cmd_path(void);
> +#endif
>  void exec_start_incoming_migration(const char *host_port, Error **errp);
>  
>  void exec_start_outgoing_migration(MigrationState *s, const char *host_port,
> diff --git a/migration/migration.c b/migration/migration.c
> index 6d3cf5d5cd..dcbd509d56 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -65,6 +65,7 @@
>  #include "sysemu/qtest.h"
>  #include "options.h"
>  #include "sysemu/dirtylimit.h"
> +#include "qemu/sockets.h"
>  
>  static NotifierList migration_state_notifiers =
>      NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
> @@ -427,15 +428,64 @@ void migrate_add_address(SocketAddress *address)
>                        QAPI_CLONE(SocketAddress, address));
>  }
>  
> +static bool migrate_uri_parse(const char *uri,
> +                              MigrationAddress **channel,
> +                              Error **errp)
> +{
> +    g_autoptr(MigrationAddress) addr = g_new0(MigrationAddress, 1);

This cannot be g_autoptr because you're passing it out of scope at the
end of the function.

> +    SocketAddress *saddr = &addr->u.socket;

This attribution is useless. Down below you overwrite it with the result
of socket_parse.

> +    InetSocketAddress *isock = &addr->u.rdma;
> +    strList **tail = &addr->u.exec.args;
> +
> +    if (strstart(uri, "exec:", NULL)) {
> +        addr->transport = MIGRATION_ADDRESS_TYPE_EXEC;
> +#ifdef WIN32
> +        QAPI_LIST_APPEND(tail, g_strdup(exec_get_cmd_path()));
> +        QAPI_LIST_APPEND(tail, g_strdup("/c"));
> +#else
> +        QAPI_LIST_APPEND(tail, g_strdup("/bin/sh"));
> +        QAPI_LIST_APPEND(tail, g_strdup("-c"));
> +#endif
> +        QAPI_LIST_APPEND(tail, g_strdup(uri + strlen("exec:")));
> +    } else if (strstart(uri, "rdma:", NULL)) {
> +        if (inet_parse(isock, uri + strlen("rdma:"), errp)) {
> +            qapi_free_InetSocketAddress(isock);
> +            return false;
> +        }
> +        addr->transport = MIGRATION_ADDRESS_TYPE_RDMA;
> +    } else if (strstart(uri, "tcp:", NULL) ||
> +                strstart(uri, "unix:", NULL) ||
> +                strstart(uri, "vsock:", NULL) ||
> +                strstart(uri, "fd:", NULL)) {
> +        addr->transport = MIGRATION_ADDRESS_TYPE_SOCKET;
> +        saddr = socket_parse(uri, errp);
> +        if (!saddr) {
> +            qapi_free_SocketAddress(saddr);

Shouldn't free here. socket_parse() already does so on failure.

> +            return false;
> +        }

Then here you can set the values you intended to set.

addr->u.socket.type = saddr->type;
addr->u.socket.u = saddr->u;

> +    } else {
> +        error_setg(errp, "unknown migration protocol: %s", uri);
> +        return false;
> +    }
> +
> +    *channel = addr;
> +    return true;
> +}
> +
>  static void qemu_start_incoming_migration(const char *uri, Error **errp)
>  {
>      const char *p = NULL;
> +    g_autoptr(MigrationAddress) channel = g_new0(MigrationAddress, 1);

The memory is leaked here because the pointer is overwritten below. Just
set it to NULL. You can keep the g_autoptr.

>  
>      /* URI is not suitable for migration? */
>      if (!migration_channels_and_uri_compatible(uri, errp)) {
>          return;
>      }
>  
> +    if (uri && !migrate_uri_parse(uri, &channel, errp)) {
> +        return;
> +    }
> +
>      qapi_event_send_migration(MIGRATION_STATUS_SETUP);
>      if (strstart(uri, "tcp:", &p) ||
>          strstart(uri, "unix:", NULL) ||
> @@ -1671,12 +1721,17 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>      Error *local_err = NULL;
>      MigrationState *s = migrate_get_current();
>      const char *p = NULL;
> +    g_autoptr(MigrationAddress) channel = g_new0(MigrationAddress, 1);

Same here.

>  
>      /* URI is not suitable for migration? */
>      if (!migration_channels_and_uri_compatible(uri, errp)) {
>          return;
>      }
>  
> +    if (!migrate_uri_parse(uri, &channel, errp)) {
> +        return;
> +    }
> +
>      resume_requested = has_resume && resume;
>      if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
>                           resume_requested, errp)) {