[v5,12/12] livepatch: Add python bindings for livepatch operations
diff mbox series

Message ID 20191114130653.51185-13-wipawel@amazon.de
State Superseded
Headers show
Series
  • livepatch: new features and fixes
Related show

Commit Message

Pawel Wieczorkiewicz Nov. 14, 2019, 1:06 p.m. UTC
Extend the XC python bindings library to support also all common
livepatch operations and actions.

Add the python bindings for the following operations:
- status (pyxc_livepatch_status):
  Requires a payload name as an input.
  Returns a status dict containing a state string and a return code
  integer.
- action (pyxc_livepatch_action):
  Requires a payload name and an action id as an input. Timeout and
  flags are optional parameters.
  Returns None or throws an exception.
- upload (pyxc_livepatch_upload):
  Requires a payload name and a module's filename as an input.
  Returns None or throws an exception.
- list (pyxc_livepatch_list):
  Takes no parameters.
  Returns a list of dicts containing each payload's:
  * name as a string
  * state as a string
  * return code as an integer
  * list of metadata key=value strings

Each functions throws an exception error based on the errno value
received from its corresponding libxc function call.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Martin Mazein <amazein@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Leonard Foerster <foersleo@amazon.de>
Reviewed-by: Norbert Manthey <nmanthey@amazon.de>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
Changed since v4:
  * changed flags field type from uint64_t to uint32_t
  * fixed leaking fd in pyxc_livepatch_upload()

Changed since v3:
  * return None instead of integer 0 from pyxc_livepatch_action()
    and pyxc_livepatch_upload()
  * use fstat() instead of stat()
  * simplify error condition handling code for pyxc_livepatch_upload
    and also save and restore errno value
  * check done and left values to handle errors in
    pyxc_livepatch_list()
  * use PyList_SET_ITEM() to avoid the need for PyDECREF

Changed since v1:
  * changed PyList_Append() with PyList_SetItem() as requested by
    Marek
---
 tools/python/xen/lowlevel/xc/xc.c | 268 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 268 insertions(+)

Comments

Ross Lagerwall Nov. 19, 2019, 5:23 p.m. UTC | #1
On 11/14/19 1:06 PM, Pawel Wieczorkiewicz wrote:
> Extend the XC python bindings library to support also all common
> livepatch operations and actions.
> 
> Add the python bindings for the following operations:
> - status (pyxc_livepatch_status):
>   Requires a payload name as an input.
>   Returns a status dict containing a state string and a return code
>   integer.
> - action (pyxc_livepatch_action):
>   Requires a payload name and an action id as an input. Timeout and
>   flags are optional parameters.
>   Returns None or throws an exception.
> - upload (pyxc_livepatch_upload):
>   Requires a payload name and a module's filename as an input.
>   Returns None or throws an exception.
> - list (pyxc_livepatch_list):
>   Takes no parameters.
>   Returns a list of dicts containing each payload's:
>   * name as a string
>   * state as a string
>   * return code as an integer
>   * list of metadata key=value strings
> 
> Each functions throws an exception error based on the errno value
> received from its corresponding libxc function call.
> 
> Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
> Reviewed-by: Martin Mazein <amazein@amazon.de>
> Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
> Reviewed-by: Leonard Foerster <foersleo@amazon.de>
> Reviewed-by: Norbert Manthey <nmanthey@amazon.de>
> Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
> ---
snip
> +static PyObject *pyxc_livepatch_upload(XcObject *self,
> +                                       PyObject *args,
> +                                       PyObject *kwds)
> +{
> +    unsigned char *fbuf = MAP_FAILED;
> +    char *name, *filename;
> +    struct stat buf;
> +    int fd = 0, rc = -1, saved_errno;

Does fd actually need to be initialized here?

Also, initializing it to 0 seems odd because 0 is a valid fd.

> +    ssize_t len;
> +
> +    static char *kwd_list[] = { "name", "filename", NULL };
> +
> +    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "ss", kwd_list,
> +                                      &name, &filename))
> +        goto error;
> +
> +    fd = open(filename, O_RDONLY);
> +    if ( fd < 0 )
> +        goto error;
> +
> +    if ( fstat(fd, &buf) != 0 )
> +        goto error_fd;
> +
> +    len = buf.st_size;
> +    fbuf = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0);
> +    if ( fbuf == MAP_FAILED )
> +        goto error_fd;
> +
> +    rc = xc_livepatch_upload(self->xc_handle, name, fbuf, len);
> +
> +    saved_errno = errno;
> +    munmap(fbuf, len);
> +    errno = saved_errno;
> +
> +error_fd:
> +    close(fd);
> +error:
> +    return rc ? pyxc_error_to_exception(self->xc_handle) : Py_None;
> +}
snip>  static PyMethodDef pyxc_methods[] = {
>      { "domain_create", 
>        (PyCFunction)pyxc_domain_create, 
> @@ -2542,6 +2761,44 @@ static PyMethodDef pyxc_methods[] = {
>        "Returns: [int]: 0 on all permission granted; -1 if any permissions are \
>         denied\n" }, 
>  
> +    { "livepatch_status",
> +      (PyCFunction)pyxc_livepatch_status,
> +      METH_KEYWORDS, "\n"
> +      "Gets current state and return code for a specified module.\n"
> +      " name     [str]: Module name to be used\n"
> +      "Returns: [dict] on success; throwing an exception on error\n"
> +      " state    [int]: Module current state: CHECKED or APPLIED\n"
> +      " rc       [int]: Return code of last module's operation\n" },
> +
> +    { "livepatch_upload",
> +      (PyCFunction)pyxc_livepatch_upload,
> +      METH_KEYWORDS, "\n"
> +      "Uploads a module with specified name from filename.\n"
> +      " name     [str]: Module name to be used\n"
> +      " filename [str]: Filename of a module to be uploaded\n"
> +      "Returns: None on success; throwing an exception on error\n" },
> +
> +    { "livepatch_action",
> +      (PyCFunction)pyxc_livepatch_action,
> +      METH_KEYWORDS, "\n"
> +      "Performs an action (unload, revert, apply or replace) on a specified \
> +       module.\n"
> +      " name      [str]: Module name to be used\n"
> +      " action   [uint]: Action enum id\n"
> +      " timeout  [uint]: Action scheduled execution timeout\n"
> +      " flags   [ulong]: Flags specifying action's extra parameters\n"

Should this be uint and not ulong?

I expect these things could be fixed up on commit.

Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Patch
diff mbox series

diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
index 44d3606141..9a1d3b6b92 100644
--- a/tools/python/xen/lowlevel/xc/xc.c
+++ b/tools/python/xen/lowlevel/xc/xc.c
@@ -1979,6 +1979,225 @@  static PyObject *pyflask_access(PyObject *self, PyObject *args,
     return Py_BuildValue("i",ret);
 }
 
+static PyObject *pyxc_livepatch_status(XcObject *self,
+                                       PyObject *args,
+                                       PyObject *kwds)
+{
+    xen_livepatch_status_t status;
+    PyObject *info_dict = NULL;
+    char *name;
+    int rc;
+
+    static char *kwd_list[] = { "name", NULL };
+
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "s", kwd_list, &name) )
+        goto error;
+
+    rc = xc_livepatch_get(self->xc_handle, name, &status);
+    if ( rc )
+        goto error;
+
+    info_dict = Py_BuildValue(
+            "{s:i,s:i}",
+            "state",    status.state,
+            "rc",       status.rc);
+
+error:
+    return info_dict ?: pyxc_error_to_exception(self->xc_handle);
+}
+
+static PyObject *pyxc_livepatch_action(XcObject *self,
+                                       PyObject *args,
+                                       PyObject *kwds)
+{
+    int (*action_func)(xc_interface *xch, char *name, uint32_t timeout, uint32_t flags);
+    char *name;
+    unsigned int action;
+    uint32_t timeout;
+    uint32_t flags;
+    int rc = -1;
+
+    static char *kwd_list[] = { "name", "action", "timeout", "flags", NULL };
+
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "sI|Ik", kwd_list,
+                                      &name, &action, &timeout, &flags) )
+        goto error;
+
+    switch (action)
+    {
+    case LIVEPATCH_ACTION_UNLOAD:
+        action_func = xc_livepatch_unload;
+        break;
+    case LIVEPATCH_ACTION_REVERT:
+        action_func = xc_livepatch_revert;
+        break;
+    case LIVEPATCH_ACTION_APPLY:
+        action_func = xc_livepatch_apply;
+        break;
+    case LIVEPATCH_ACTION_REPLACE:
+        action_func = xc_livepatch_replace;
+        break;
+    default:
+        goto error;
+    }
+
+    rc = action_func(self->xc_handle, name, timeout, flags);
+
+error:
+    return rc ? pyxc_error_to_exception(self->xc_handle) : Py_None;
+}
+
+static PyObject *pyxc_livepatch_upload(XcObject *self,
+                                       PyObject *args,
+                                       PyObject *kwds)
+{
+    unsigned char *fbuf = MAP_FAILED;
+    char *name, *filename;
+    struct stat buf;
+    int fd = 0, rc = -1, saved_errno;
+    ssize_t len;
+
+    static char *kwd_list[] = { "name", "filename", NULL };
+
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "ss", kwd_list,
+                                      &name, &filename))
+        goto error;
+
+    fd = open(filename, O_RDONLY);
+    if ( fd < 0 )
+        goto error;
+
+    if ( fstat(fd, &buf) != 0 )
+        goto error_fd;
+
+    len = buf.st_size;
+    fbuf = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0);
+    if ( fbuf == MAP_FAILED )
+        goto error_fd;
+
+    rc = xc_livepatch_upload(self->xc_handle, name, fbuf, len);
+
+    saved_errno = errno;
+    munmap(fbuf, len);
+    errno = saved_errno;
+
+error_fd:
+    close(fd);
+error:
+    return rc ? pyxc_error_to_exception(self->xc_handle) : Py_None;
+}
+
+static PyObject *pyxc_livepatch_list(XcObject *self)
+{
+    PyObject *list = Py_None;
+    unsigned int nr, done, left, i;
+    xen_livepatch_status_t *info = NULL;
+    char *name = NULL;
+    char *metadata = NULL;
+    uint32_t *len = NULL;
+    uint32_t *metadata_len = NULL;
+    uint32_t name_total_size, metadata_total_size;
+    uint32_t name_off, metadata_off;
+    int rc;
+
+    done = left = 0;
+    rc = xc_livepatch_list_get_sizes(self->xc_handle, &nr,
+                                     &name_total_size, &metadata_total_size);
+    if ( rc )
+        goto error;
+
+    if ( nr == 0 )
+        return PyList_New(0);
+
+    rc = ENOMEM;
+    info = malloc(nr * sizeof(*info));
+    if ( !info )
+        goto error;
+
+    name = malloc(name_total_size * sizeof(*name));
+    if ( !name )
+        goto error;
+
+    len = malloc(nr * sizeof(*len));
+    if ( !len )
+        goto error;
+
+    metadata = malloc(metadata_total_size * sizeof(*metadata));
+    if ( !metadata )
+        goto error;
+
+    metadata_len = malloc(nr * sizeof(*metadata_len));
+    if ( !metadata_len )
+        goto error;
+
+    rc = xc_livepatch_list(self->xc_handle, nr, 0, info,
+                           name, len, name_total_size,
+                           metadata, metadata_len, metadata_total_size,
+                           &done, &left);
+    if ( rc )
+        goto error;
+
+    if ( done != nr || left > 0 )
+    {
+        rc = EFAULT;
+        goto error;
+    }
+
+    list = PyList_New(done);
+    name_off = metadata_off = 0;
+    for ( i = 0; i < done; i++ )
+    {
+        PyObject *info_dict, *metadata_list;
+        char *name_str, *metadata_str;
+
+        name_str = name + name_off;
+        metadata_str = metadata + metadata_off;
+
+        metadata_list = PyList_New(0);
+        for ( char *s = metadata_str; s < metadata_str + metadata_len[i]; s += strlen(s) + 1 )
+        {
+            PyObject *field = Py_BuildValue("s", s);
+            if ( field == NULL )
+            {
+                Py_DECREF(list);
+                Py_DECREF(metadata_list);
+                rc = EFAULT;
+                goto error;
+            }
+
+            PyList_Append(metadata_list, field);
+            Py_DECREF(field);
+        }
+
+        info_dict = Py_BuildValue(
+            "{s:s,s:i,s:i,s:N}",
+            "name",     name_str,
+            "state",    info[i].state,
+            "rc",       info[i].rc,
+            "metadata", metadata_list);
+
+        if ( info_dict == NULL )
+        {
+            Py_DECREF(list);
+            Py_DECREF(metadata_list);
+            rc = EFAULT;
+            goto error;
+        }
+        PyList_SET_ITEM(list, i, info_dict);
+
+        name_off += len[i];
+        metadata_off += metadata_len[i];
+    }
+
+error:
+    free(info);
+    free(name);
+    free(len);
+    free(metadata);
+    free(metadata_len);
+    return rc ? pyxc_error_to_exception(self->xc_handle) : list;
+}
+
 static PyMethodDef pyxc_methods[] = {
     { "domain_create", 
       (PyCFunction)pyxc_domain_create, 
@@ -2542,6 +2761,44 @@  static PyMethodDef pyxc_methods[] = {
       "Returns: [int]: 0 on all permission granted; -1 if any permissions are \
        denied\n" }, 
 
+    { "livepatch_status",
+      (PyCFunction)pyxc_livepatch_status,
+      METH_KEYWORDS, "\n"
+      "Gets current state and return code for a specified module.\n"
+      " name     [str]: Module name to be used\n"
+      "Returns: [dict] on success; throwing an exception on error\n"
+      " state    [int]: Module current state: CHECKED or APPLIED\n"
+      " rc       [int]: Return code of last module's operation\n" },
+
+    { "livepatch_upload",
+      (PyCFunction)pyxc_livepatch_upload,
+      METH_KEYWORDS, "\n"
+      "Uploads a module with specified name from filename.\n"
+      " name     [str]: Module name to be used\n"
+      " filename [str]: Filename of a module to be uploaded\n"
+      "Returns: None on success; throwing an exception on error\n" },
+
+    { "livepatch_action",
+      (PyCFunction)pyxc_livepatch_action,
+      METH_KEYWORDS, "\n"
+      "Performs an action (unload, revert, apply or replace) on a specified \
+       module.\n"
+      " name      [str]: Module name to be used\n"
+      " action   [uint]: Action enum id\n"
+      " timeout  [uint]: Action scheduled execution timeout\n"
+      " flags   [ulong]: Flags specifying action's extra parameters\n"
+      "Returns: None on success; throwing an exception on error\n" },
+
+    { "livepatch_list",
+      (PyCFunction)pyxc_livepatch_list,
+      METH_NOARGS, "\n"
+      "List all uploaded livepatch modules with their current state and metadata.\n"
+      "Returns: [list of dicts] on success; throwing an exception on error\n"
+      " name     [str]: Module name\n"
+      " state    [int]: Module current state: CHECKED or APPLIED\n"
+      " rc       [int]: Return code of last module's operation\n"
+      " metadata [list]: List of module's metadata 'key=value' strings\n" },
+
     { NULL, NULL, 0, NULL }
 };
 
@@ -2653,6 +2910,17 @@  PyMODINIT_FUNC initxc(void)
     PyModule_AddIntConstant(m, "XEN_SCHEDULER_CREDIT", XEN_SCHEDULER_CREDIT);
     PyModule_AddIntConstant(m, "XEN_SCHEDULER_CREDIT2", XEN_SCHEDULER_CREDIT2);
 
+    /* Expose livepatch constants to Python */
+    PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_UNLOAD", LIVEPATCH_ACTION_UNLOAD);
+    PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_REVERT", LIVEPATCH_ACTION_REVERT);
+    PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_APPLY", LIVEPATCH_ACTION_APPLY);
+    PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_REPLACE", LIVEPATCH_ACTION_REPLACE);
+
+    PyModule_AddIntConstant(m, "LIVEPATCH_ACTION_APPLY_NODEPS", LIVEPATCH_ACTION_APPLY_NODEPS);
+
+    PyModule_AddIntConstant(m, "LIVEPATCH_STATE_APPLIED", LIVEPATCH_STATE_APPLIED);
+    PyModule_AddIntConstant(m, "LIVEPATCH_STATE_CHECKED", LIVEPATCH_STATE_CHECKED);
+
 #if PY_MAJOR_VERSION >= 3
     return m;
 #endif