[lxc-devel] [PATCH] Add get_interfaces to the API - v3
S.Çağlar Onur
caglar at 10ur.org
Wed Sep 18 18:53:33 UTC 2013
Do you want me to sync this on top of staging and re-send?I think they are
conflicting right now.
On Wed, Sep 18, 2013 at 2:47 PM, Stéphane Graber <stgraber at ubuntu.com>wrote:
> On Mon, Sep 16, 2013 at 05:01:11PM -0400, S.Çağlar Onur wrote:
> > get_ips accepts an interface name as a parameter but there was no
> > way to get the interfaces names from the container. This patch
> > introduces a new get_interfaces call to the API so that users
> > can obtain the name of the interfaces.
> >
> > Support for python bindings also introduced as a part of this version.
> >
> > Signed-off-by: S.Çağlar Onur <caglar at 10ur.org>
>
> Acked-by: Stéphane Graber <stgraber at ubuntu.com>
>
> > ---
> > src/lxc/lxccontainer.c | 129
> ++++++++++++++++++++++++++----------
> > src/lxc/lxccontainer.h | 3 +
> > src/lxc/utils.c | 22 +++++-
> > src/lxc/utils.h | 1 +
> > src/python-lxc/examples/api_test.py | 5 ++
> > src/python-lxc/lxc.c | 60 +++++++++++++++--
> > src/python-lxc/lxc/__init__.py | 8 +++
> > 7 files changed, 189 insertions(+), 39 deletions(-)
> >
> > diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> > index 79237df..8621cd8 100644
> > --- a/src/lxc/lxccontainer.c
> > +++ b/src/lxc/lxccontainer.c
> > @@ -1179,23 +1179,26 @@ static bool lxcapi_clear_config_item(struct
> lxc_container *c, const char *key)
> > return ret == 0;
> > }
> >
> > -char** lxcapi_get_ips(struct lxc_container *c, char* interface, char*
> family, int scope)
> > -{
> > - int count = 0;
> > - struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > - char addressOutputBuffer[INET6_ADDRSTRLEN];
> > - void *tempAddrPtr = NULL;
> > - char **addresses = NULL, **temp;
> > - char *address = NULL;
> > +static inline void exit_from_ns(struct lxc_container *c, int
> *old_netns, int *new_netns) {
> > + /* Switch back to original netns */
> > + if (*old_netns >= 0 && setns(*old_netns, CLONE_NEWNET))
> > + SYSERROR("failed to setns");
> > + if (*new_netns >= 0)
> > + close(*new_netns);
> > + if (*old_netns >= 0)
> > + close(*old_netns);
> > +}
> > +
> > +static inline bool enter_to_ns(struct lxc_container *c, int *old_netns,
> int *new_netns) {
> > + int ret = 0;
> > char new_netns_path[MAXPATHLEN];
> > - int old_netns = -1, new_netns = -1, ret = 0;
> >
> > if (!c->is_running(c))
> > goto out;
> >
> > /* Save reference to old netns */
> > - old_netns = open("/proc/self/ns/net", O_RDONLY);
> > - if (old_netns < 0) {
> > + *old_netns = open("/proc/self/ns/net", O_RDONLY);
> > + if (*old_netns < 0) {
> > SYSERROR("failed to open /proc/self/ns/net");
> > goto out;
> > }
> > @@ -1205,16 +1208,91 @@ char** lxcapi_get_ips(struct lxc_container *c,
> char* interface, char* family, in
> > if (ret < 0 || ret >= MAXPATHLEN)
> > goto out;
> >
> > - new_netns = open(new_netns_path, O_RDONLY);
> > - if (new_netns < 0) {
> > + *new_netns = open(new_netns_path, O_RDONLY);
> > + if (*new_netns < 0) {
> > SYSERROR("failed to open %s", new_netns_path);
> > goto out;
> > }
> >
> > - if (setns(new_netns, CLONE_NEWNET)) {
> > + if (setns(*new_netns, CLONE_NEWNET)) {
> > SYSERROR("failed to setns");
> > goto out;
> > }
> > + return true;
> > +out:
> > + exit_from_ns(c, old_netns, new_netns);
> > + return false;
> > +}
> > +
> > +static char** lxcapi_get_interfaces(struct lxc_container *c)
> > +{
> > + int count = 0, i;
> > + bool found = false;
> > + struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > + char **interfaces = NULL, **temp;
> > + int old_netns = -1, new_netns = -1;
> > +
> > + if (!enter_to_ns(c, &old_netns, &new_netns))
> > + goto out;
> > +
> > + /* Grab the list of interfaces */
> > + if (getifaddrs(&interfaceArray)) {
> > + SYSERROR("failed to get interfaces list");
> > + goto out;
> > + }
> > +
> > + /* Iterate through the interfaces */
> > + for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr =
> tempIfAddr->ifa_next) {
> > + /*
> > + * WARNING: Following "for" loop does a linear search over
> the interfaces array
> > + * For the containers with lots of interfaces this may be
> problematic.
> > + * I'm not expecting this to be the common usage but if it
> turns out to be
> > + * than using binary search or a hash table could be
> more elegant solution.
> > + */
> > + for (i = 0; i < count; i++) {
> > + if (strcmp(interfaces[i], tempIfAddr->ifa_name) ==
> 0) {
> > + found = true;
> > + break;
> > + }
> > + }
> > +
> > + if (!found) {
> > + count += 1;
> > + temp = realloc(interfaces, count *
> sizeof(*interfaces));
> > + if (!temp) {
> > + count -= 1;
> > + goto out;
> > + }
> > + interfaces = temp;
> > + interfaces[count - 1] =
> strdup(tempIfAddr->ifa_name);
> > + }
> > + found = false;
> > + }
> > +
> > +out:
> > + if (interfaceArray)
> > + freeifaddrs(interfaceArray);
> > +
> > + exit_from_ns(c, &old_netns, &new_netns);
> > +
> > + /* Append NULL to the array */
> > + interfaces = (char **)lxc_append_null_to_array((void
> **)interfaces, count);
> > +
> > + return interfaces;
> > +}
> > +
> > +static char** lxcapi_get_ips(struct lxc_container *c, char* interface,
> char* family, int scope)
> > +{
> > + int count = 0;
> > + struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
> > + char addressOutputBuffer[INET6_ADDRSTRLEN];
> > + void *tempAddrPtr = NULL;
> > + char **addresses = NULL, **temp;
> > + char *address = NULL;
> > + int old_netns = -1, new_netns = -1;
> > +
> > + if (!enter_to_ns(c, &old_netns, &new_netns))
> > + goto out;
> >
> > /* Grab the list of interfaces */
> > if (getifaddrs(&interfaceArray)) {
> > @@ -1265,28 +1343,10 @@ out:
> > if(interfaceArray)
> > freeifaddrs(interfaceArray);
> >
> > - /* Switch back to original netns */
> > - if (old_netns >= 0 && setns(old_netns, CLONE_NEWNET))
> > - SYSERROR("failed to setns");
> > - if (new_netns >= 0)
> > - close(new_netns);
> > - if (old_netns >= 0)
> > - close(old_netns);
> > + exit_from_ns(c, &old_netns, &new_netns);
> >
> > /* Append NULL to the array */
> > - if (count) {
> > - count++;
> > - temp = realloc(addresses, count * sizeof(*addresses));
> > - if (!temp) {
> > - int i;
> > - for (i = 0; i < count-1; i++)
> > - free(addresses[i]);
> > - free(addresses);
> > - return NULL;
> > - }
> > - addresses = temp;
> > - addresses[count - 1] = NULL;
> > - }
> > + addresses = (char **)lxc_append_null_to_array((void **)addresses,
> count);
> >
> > return addresses;
> > }
> > @@ -2576,6 +2636,7 @@ struct lxc_container *lxc_container_new(const char
> *name, const char *configpath
> > c->get_config_path = lxcapi_get_config_path;
> > c->set_config_path = lxcapi_set_config_path;
> > c->clone = lxcapi_clone;
> > + c->get_interfaces = lxcapi_get_interfaces;
> > c->get_ips = lxcapi_get_ips;
> > c->attach = lxcapi_attach;
> > c->attach_run_wait = lxcapi_attach_run_wait;
> > diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
> > index f9ae43b..89b55bd 100644
> > --- a/src/lxc/lxccontainer.h
> > +++ b/src/lxc/lxccontainer.h
> > @@ -90,6 +90,9 @@ struct lxc_container {
> > * the length which was our would be printed. */
> > int (*get_config_item)(struct lxc_container *c, const char *key,
> char *retv, int inlen);
> > int (*get_keys)(struct lxc_container *c, const char *key, char
> *retv, int inlen);
> > + // Return interface names. The result is strdup()d, so free the
> result.
> > + char** (*get_interfaces)(struct lxc_container *c);
> > + // Return IP addresses. The result is strdup()d, so free the
> result.
> > char** (*get_ips)(struct lxc_container *c, char* interface, char*
> family, int scope);
> > /*
> > * get_cgroup_item returns the number of bytes read, or an error
> (<0).
> > diff --git a/src/lxc/utils.c b/src/lxc/utils.c
> > index 78b234d..924cc19 100644
> > --- a/src/lxc/utils.c
> > +++ b/src/lxc/utils.c
> > @@ -852,7 +852,7 @@ int lxc_write_to_file(const char *filename, const
> void* buf, size_t count, bool
> > return -1;
> > ret = lxc_write_nointr(fd, buf, count);
> > if (ret < 0)
> > - goto out_error;
> > + goto out_error;
> > if ((size_t)ret != count)
> > goto out_error;
> > if (add_newline) {
> > @@ -899,3 +899,23 @@ int lxc_read_from_file(const char *filename, void*
> buf, size_t count)
> > errno = saved_errno;
> > return ret;
> > }
> > +
> > +void **lxc_append_null_to_array(void **array, size_t count)
> > +{
> > + void **temp;
> > +
> > + /* Append NULL to the array */
> > + if (count) {
> > + temp = realloc(array, (count + 1) * sizeof(*array));
> > + if (!temp) {
> > + int i;
> > + for (i = 0; i < count; i++)
> > + free(array[i]);
> > + free(array);
> > + return NULL;
> > + }
> > + array = temp;
> > + array[count] = NULL;
> > + }
> > + return array;
> > +}
> > diff --git a/src/lxc/utils.h b/src/lxc/utils.h
> > index ba7cfb3..55f98fa 100644
> > --- a/src/lxc/utils.h
> > +++ b/src/lxc/utils.h
> > @@ -236,4 +236,5 @@ extern void lxc_free_array(void **array, lxc_free_fn
> element_free_fn);
> > extern size_t lxc_array_len(void **array);
> > extern void **lxc_dup_array(void **array, lxc_dup_fn element_dup_fn,
> lxc_free_fn element_free_fn);
> >
> > +extern void **lxc_append_null_to_array(void **array, size_t count);
> > #endif
> > diff --git a/src/python-lxc/examples/api_test.py
> b/src/python-lxc/examples/api_test.py
> > index e078d2b..4754332 100644
> > --- a/src/python-lxc/examples/api_test.py
> > +++ b/src/python-lxc/examples/api_test.py
> > @@ -89,6 +89,11 @@ assert(container.init_pid > 1)
> > assert(container.running)
> > assert(container.state == "RUNNING")
> >
> > +
> > +## Checking IP address
> > +print("Getting the interface names")
> > +assert(container.get_interfaces() == ('lo', 'eth0'))
> > +
> > ## Checking IP address
> > print("Getting the IP addresses")
> >
> > diff --git a/src/python-lxc/lxc.c b/src/python-lxc/lxc.c
> > index bd053a7..b6e0804 100644
> > --- a/src/python-lxc/lxc.c
> > +++ b/src/python-lxc/lxc.c
> > @@ -411,6 +411,52 @@ Container_get_keys(Container *self, PyObject *args,
> PyObject *kwds)
> > }
> >
> > static PyObject *
> > +Container_get_interfaces(Container *self)
> > +{
> > + int i = 0;
> > + char** interfaces = NULL;
> > +
> > + PyObject* ret;
> > +
> > + /* Get the interfaces */
> > + interfaces = self->container->get_interfaces(self->container);
> > + if (!interfaces)
> > + return PyTuple_New(0);
> > +
> > + /* Count the entries */
> > + while (interfaces[i])
> > + i++;
> > +
> > + /* Create the new tuple */
> > + ret = PyTuple_New(i);
> > + if (!ret)
> > + return NULL;
> > +
> > + /* Add the entries to the tuple and free the memory */
> > + i = 0;
> > + while (interfaces[i]) {
> > + PyObject *unicode = PyUnicode_FromString(interfaces[i]);
> > + if (!unicode) {
> > + Py_DECREF(ret);
> > + ret = NULL;
> > + break;
> > + }
> > + PyTuple_SET_ITEM(ret, i, unicode);
> > + i++;
> > + }
> > +
> > + /* Free the list of IPs */
> > + i = 0;
> > + while (interfaces[i]) {
> > + free(interfaces[i]);
> > + i++;
> > + }
> > + free(interfaces);
> > +
> > + return ret;
> > +}
> > +
> > +static PyObject *
> > Container_get_ips(Container *self, PyObject *args, PyObject *kwds)
> > {
> > static char *kwlist[] = {"interface", "family", "scope", NULL};
> > @@ -898,15 +944,15 @@ LXC_arch_to_personality(PyObject *self, PyObject
> *arg)
> > PyErr_SetString(PyExc_ValueError, "Expected a string");
> > return NULL;
> > }
> > -
> > +
> > pystr = PyUnicode_AsUTF8String(arg);
> > if (!pystr)
> > return NULL;
> > -
> > +
> > str = PyBytes_AsString(pystr);
> > if (!str)
> > goto out;
> > -
> > +
> > rv = lxc_config_parse_arch(str);
> > if (rv == -1)
> > PyErr_SetString(PyExc_KeyError, "Failed to lookup
> architecture.");
> > @@ -1025,6 +1071,12 @@ static PyMethodDef Container_methods[] = {
> > "\n"
> > "Get a list of valid sub-keys for a key."
> > },
> > + {"get_interfaces", (PyCFunction)Container_get_interfaces,
> > + METH_NOARGS,
> > + "get_interface() -> tuple\n"
> > + "\n"
> > + "Get a tuple of interfaces for the container."
> > + },
> > {"get_ips", (PyCFunction)Container_get_ips,
> > METH_VARARGS|METH_KEYWORDS,
> > "get_ips(interface, family, scope) -> tuple\n"
> > @@ -1205,7 +1257,7 @@ PyInit__lxc(void)
> >
> > /* add constants */
> > d = PyModule_GetDict(m);
> > -
> > +
> > #define PYLXC_EXPORT_CONST(c) PyDict_SetItemString(d, #c,
> PyLong_FromLong(c))
> >
> > /* environment variable handling */
> > diff --git a/src/python-lxc/lxc/__init__.py
> b/src/python-lxc/lxc/__init__.py
> > index 3fb76dc..6a29903 100644
> > --- a/src/python-lxc/lxc/__init__.py
> > +++ b/src/python-lxc/lxc/__init__.py
> > @@ -333,6 +333,14 @@ class Container(_lxc.Container):
> > else:
> > return value
> >
> > + def get_interfaces(self):
> > + """
> > + Get a tuple of interfaces for the container.
> > + """
> > +
> > + return _lxc.Container.get_interfaces(self)
> > +
> > +
> > def get_ips(self, interface=None, family=None, scope=None,
> timeout=0):
> > """
> > Get a tuple of IPs for the container.
> > --
> > 1.8.1.2
> >
> >
> >
> ------------------------------------------------------------------------------
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> > _______________________________________________
> > Lxc-devel mailing list
> > Lxc-devel at lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/lxc-devel
>
> --
> Stéphane Graber
> Ubuntu developer
> http://www.ubuntu.com
>
--
S.Çağlar Onur <caglar at 10ur.org>
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