[lxc-devel] [PATCH] Add get_interfaces to the API - v2
S.Çağlar Onur
caglar at 10ur.org
Mon Sep 16 18:26:47 UTC 2013
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.
Signed-off-by: S.Çağlar Onur <caglar at 10ur.org>
---
src/lxc/lxccontainer.c | 117 ++++++++++++++++++++++++++++++++++---------------
src/lxc/lxccontainer.h | 1 +
src/lxc/utils.c | 22 +++++++++-
src/lxc/utils.h | 1 +
4 files changed, 105 insertions(+), 36 deletions(-)
diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 79237df..6aa59fc 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 +1208,78 @@ 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;
+ 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) {
+ /* filter out loopback interface */
+ if(tempIfAddr->ifa_addr == NULL || tempIfAddr->ifa_addr->sa_family != AF_PACKET || strcmp("lo", tempIfAddr->ifa_name) == 0)
+ continue;
+
+ count += 1;
+ temp = realloc(interfaces, count * sizeof(*interfaces));
+ if (!temp) {
+ count -= 1;
+ goto out;
+ }
+ interfaces = temp;
+ interfaces[count - 1] = strdup(tempIfAddr->ifa_name);
+ }
+
+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)) {
@@ -1243,7 +1308,6 @@ char** lxcapi_get_ips(struct lxc_container *c, char* interface, char* family, in
continue;
else if (!interface && strcmp("lo", tempIfAddr->ifa_name) == 0)
continue;
-
address = (char *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
tempAddrPtr,
addressOutputBuffer,
@@ -1265,28 +1329,10 @@ 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 +2622,7 @@ 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..f17d975 100644
--- a/src/lxc/lxccontainer.h
+++ b/src/lxc/lxccontainer.h
@@ -90,6 +90,7 @@ 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);
+ char** (*get_interfaces)(struct lxc_container *c);
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
--
1.8.1.2
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