Re: [PATCH v5 1/3] qio: add support for SO_PEERCRED for socket channel

2024-04-12 Thread Paolo Bonzini
On Thu, Apr 11, 2024 at 2:14 PM Anthony Harivel  wrote:
>
> The function qio_channel_get_peercred() returns a pointer to the
> credentials of the peer process connected to this socket.
>
> This credentials structure is defined in  as follows:
>
> struct ucred {
> pid_t pid;/* Process ID of the sending process */
> uid_t uid;/* User ID of the sending process */
> gid_t gid;/* Group ID of the sending process */
> };
>
> The use of this function is possible only for connected AF_UNIX stream
> sockets and for AF_UNIX stream and datagram socket pairs.
>
> On platform other than Linux, the function return 0.
>
> Signed-off-by: Anthony Harivel 
> ---
>  include/io/channel.h | 21 +
>  io/channel-socket.c  | 28 
>  io/channel.c | 13 +
>  3 files changed, 62 insertions(+)
>
> diff --git a/include/io/channel.h b/include/io/channel.h
> index 7986c49c713a..bdf0bca92ae2 100644
> --- a/include/io/channel.h
> +++ b/include/io/channel.h
> @@ -160,6 +160,9 @@ struct QIOChannelClass {
>void *opaque);
>  int (*io_flush)(QIOChannel *ioc,
>  Error **errp);
> +int (*io_peerpid)(QIOChannel *ioc,
> +   unsigned int *pid,
> +   Error **errp);
>  };
>
>  /* General I/O handling functions */
> @@ -981,4 +984,22 @@ int coroutine_mixed_fn 
> qio_channel_writev_full_all(QIOChannel *ioc,
>  int qio_channel_flush(QIOChannel *ioc,
>Error **errp);
>
> +/**
> + * qio_channel_get_peercred:
> + * @ioc: the channel object
> + * @pid: pointer to pid
> + * @errp: pointer to a NULL-initialized error object
> + *
> + * Returns the pid of the peer process connected to this socket.
> + *
> + * The use of this function is possible only for connected
> + * AF_UNIX stream sockets and for AF_UNIX stream and datagram
> + * socket pairs on Linux.
> + * Return -1 on error with pid -1 for the non-Linux OS.

with pid -1 -> and set *pid to -1.

> + */
>  static const TypeInfo qio_channel_socket_info = {
> diff --git a/io/channel.c b/io/channel.c
> index a1f12f8e9096..e3f17c24a00f 100644
> --- a/io/channel.c
> +++ b/io/channel.c
> @@ -548,6 +548,19 @@ void qio_channel_set_cork(QIOChannel *ioc,
>  }
>  }
>
> +int qio_channel_get_peerpid(QIOChannel *ioc,
> + unsigned int *pid,
> + Error **errp)
> +{
> +QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
> +
> +if (!klass->io_peerpid) {
> +error_setg(errp, "Channel does not support peer pid");

Missing for consistency:

+*pid = -1;

> +return -1;
> +}
> +klass->io_peerpid(ioc, pid, errp);
> +return 0;

The error from klass->io_peerpid is ignored:

-klass->io_peerpid(ioc, pid, errp);
-return 0;
+return klass->io_peerpid(ioc, pid, errp);

Paolo




[PATCH v5 1/3] qio: add support for SO_PEERCRED for socket channel

2024-04-11 Thread Anthony Harivel
The function qio_channel_get_peercred() returns a pointer to the
credentials of the peer process connected to this socket.

This credentials structure is defined in  as follows:

struct ucred {
pid_t pid;/* Process ID of the sending process */
uid_t uid;/* User ID of the sending process */
gid_t gid;/* Group ID of the sending process */
};

The use of this function is possible only for connected AF_UNIX stream
sockets and for AF_UNIX stream and datagram socket pairs.

On platform other than Linux, the function return 0.

Signed-off-by: Anthony Harivel 
---
 include/io/channel.h | 21 +
 io/channel-socket.c  | 28 
 io/channel.c | 13 +
 3 files changed, 62 insertions(+)

diff --git a/include/io/channel.h b/include/io/channel.h
index 7986c49c713a..bdf0bca92ae2 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -160,6 +160,9 @@ struct QIOChannelClass {
   void *opaque);
 int (*io_flush)(QIOChannel *ioc,
 Error **errp);
+int (*io_peerpid)(QIOChannel *ioc,
+   unsigned int *pid,
+   Error **errp);
 };
 
 /* General I/O handling functions */
@@ -981,4 +984,22 @@ int coroutine_mixed_fn 
qio_channel_writev_full_all(QIOChannel *ioc,
 int qio_channel_flush(QIOChannel *ioc,
   Error **errp);
 
+/**
+ * qio_channel_get_peercred:
+ * @ioc: the channel object
+ * @pid: pointer to pid
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Returns the pid of the peer process connected to this socket.
+ *
+ * The use of this function is possible only for connected
+ * AF_UNIX stream sockets and for AF_UNIX stream and datagram
+ * socket pairs on Linux.
+ * Return -1 on error with pid -1 for the non-Linux OS.
+ *
+ */
+int qio_channel_get_peerpid(QIOChannel *ioc,
+ unsigned int *pid,
+ Error **errp);
+
 #endif /* QIO_CHANNEL_H */
diff --git a/io/channel-socket.c b/io/channel-socket.c
index 3a899b060858..608bcf066ecd 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -841,6 +841,33 @@ qio_channel_socket_set_cork(QIOChannel *ioc,
 socket_set_cork(sioc->fd, v);
 }
 
+static int
+qio_channel_socket_get_peerpid(QIOChannel *ioc,
+   unsigned int *pid,
+   Error **errp)
+{
+#ifdef CONFIG_LINUX
+QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
+Error *err = NULL;
+socklen_t len = sizeof(struct ucred);
+
+struct ucred cred;
+if (getsockopt(sioc->fd,
+   SOL_SOCKET, SO_PEERCRED,
+   , ) == -1) {
+error_setg_errno(, errno, "Unable to get peer credentials");
+error_propagate(errp, err);
+*pid = -1;
+return -1;
+}
+*pid = (unsigned int)cred.pid;
+return 0;
+#else
+error_setg(errp, "Unsupported feature");
+*pid = -1;
+return -1;
+#endif
+}
 
 static int
 qio_channel_socket_close(QIOChannel *ioc,
@@ -938,6 +965,7 @@ static void qio_channel_socket_class_init(ObjectClass 
*klass,
 #ifdef QEMU_MSG_ZEROCOPY
 ioc_klass->io_flush = qio_channel_socket_flush;
 #endif
+ioc_klass->io_peerpid = qio_channel_socket_get_peerpid;
 }
 
 static const TypeInfo qio_channel_socket_info = {
diff --git a/io/channel.c b/io/channel.c
index a1f12f8e9096..e3f17c24a00f 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -548,6 +548,19 @@ void qio_channel_set_cork(QIOChannel *ioc,
 }
 }
 
+int qio_channel_get_peerpid(QIOChannel *ioc,
+ unsigned int *pid,
+ Error **errp)
+{
+QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
+
+if (!klass->io_peerpid) {
+error_setg(errp, "Channel does not support peer pid");
+return -1;
+}
+klass->io_peerpid(ioc, pid, errp);
+return 0;
+}
 
 off_t qio_channel_io_seek(QIOChannel *ioc,
   off_t offset,
-- 
2.44.0