[ovs-dev] [PATCH] netdev: Add methods to do netdev-specific argument comparisons.
Justin Pettit
jpettit at nicira.com
Tue Jun 14 02:44:21 UTC 2011
When doing a netdev_open(), a check is first done to make sure the
arguments are equivalent for any open devices with the same name. In
most cases, a simple shash comparison is sufficient. However, IPsec
key configuration is handled by an external program, so it is not pushed
down into the kernel module. Thus, when the "unparse_config" method is
called on an existing IPsec-based vport, a simple comparison with the
returned data will not match the original configuration. This commit
adds code to allow netdev-specific argument comparisons and has
"ipsec_gre" make use of them.
Bug #5575
---
lib/netdev-dummy.c | 3 +-
lib/netdev-linux.c | 1 +
lib/netdev-provider.h | 11 +++++++++
lib/netdev-vport.c | 55 +++++++++++++++++++++++++++++++++++++++++++++---
lib/netdev.c | 17 +++++++++++++-
5 files changed, 80 insertions(+), 7 deletions(-)
diff --git a/lib/netdev-dummy.c b/lib/netdev-dummy.c
index 472bdb8..9cd06f1 100644
--- a/lib/netdev-dummy.c
+++ b/lib/netdev-dummy.c
@@ -226,7 +226,8 @@ static const struct netdev_class dummy_class = {
netdev_dummy_create,
netdev_dummy_destroy,
- NULL,
+ NULL, /* set_config */
+ NULL, /* config_equal */
netdev_dummy_open,
netdev_dummy_close,
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index 04c6226..1667282 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -2247,6 +2247,7 @@ netdev_linux_change_seq(const struct netdev *netdev)
CREATE, \
netdev_linux_destroy, \
NULL, /* set_config */ \
+ NULL, /* config_equal */ \
\
netdev_linux_open, \
netdev_linux_close, \
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index 6769014..94d22d5 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -52,6 +52,8 @@ const char *netdev_dev_get_name(const struct netdev_dev *);
struct netdev_dev *netdev_dev_from_name(const char *name);
void netdev_dev_get_devices(const struct netdev_class *,
struct shash *device_list);
+bool netdev_dev_args_equal(const struct netdev_dev *netdev_dev,
+ const struct shash *args);
static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
const struct netdev_class *class_)
@@ -135,6 +137,15 @@ struct netdev_class {
*/
int (*set_config)(struct netdev_dev *netdev_dev, const struct shash *args);
+ /* Returns true if 'args' is equivalent to the 'args' field in
+ * 'netdev_dev', otherwise false.
+ *
+ * If no special processing needs to be done beyond a simple
+ * shash comparison, this may be a null pointer.
+ */
+ bool (*config_equal)(const struct netdev_dev *netdev_dev,
+ const struct shash *args);
+
/* Attempts to open a network device. On success, sets 'netdevp'
* to the new network device.
*
diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c
index 28a1bfb..bc7d050 100644
--- a/lib/netdev-vport.c
+++ b/lib/netdev-vport.c
@@ -68,6 +68,7 @@ struct vport_class {
int (*unparse_config)(const char *name, const char *type,
const struct nlattr *options, size_t options_len,
struct shash *args);
+ bool (*config_equal)(const struct shash *nd_args, const struct shash *args);
};
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
@@ -315,6 +316,20 @@ netdev_vport_set_config(struct netdev_dev *dev_, const struct shash *args)
return error;
}
+static bool
+netdev_vport_config_equal(const struct netdev_dev *dev_,
+ const struct shash *args)
+{
+ const struct netdev_class *netdev_class = netdev_dev_get_class(dev_);
+ const struct vport_class *vport_class = vport_class_cast(netdev_class);
+
+ if (vport_class->config_equal) {
+ return vport_class->config_equal(&dev_->args, args);
+ } else {
+ return smap_equal(&dev_->args, args);
+ }
+}
+
static int
netdev_vport_send(struct netdev *netdev, const void *data, size_t size)
{
@@ -868,6 +883,37 @@ unparse_patch_config(const char *name OVS_UNUSED, const char *type OVS_UNUSED,
smap_add(args, "peer", nl_attr_get_string(a[ODP_PATCH_ATTR_PEER]));
return 0;
}
+
+/* Returns true if 'nd_args' is equivalent to 'args', otherwise false.
+ * Typically, 'nd_args' is the result of a call to unparse_tunnel_config()
+ * and 'args' is the original definition of the port.
+ *
+ * IPsec key configuration is handled by an external program, so it is not
+ * pushed down into the kernel module. Thus, when the "unparse_config"
+ * method is called on an existing IPsec-based vport, a simple
+ * comparison with the returned data will not match the original
+ * configuration. This function ignores configuration about keys when
+ * doing a comparison.
+ */
+static bool
+config_equal_ipsec(const struct shash *nd_args, const struct shash *args)
+{
+ struct shash tmp;
+ bool result;
+
+ smap_clone(&tmp, args);
+
+ shash_find_and_delete(&tmp, "psk");
+ shash_find_and_delete(&tmp, "peer_cert");
+ shash_find_and_delete(&tmp, "certificate");
+ shash_find_and_delete(&tmp, "private_key");
+ shash_find_and_delete(&tmp, "use_ssl_cert");
+
+ result = smap_equal(&tmp, nd_args);
+ smap_destroy(&tmp);
+
+ return result;
+}
#define VPORT_FUNCTIONS(GET_STATUS) \
NULL, \
@@ -877,6 +923,7 @@ unparse_patch_config(const char *name OVS_UNUSED, const char *type OVS_UNUSED,
netdev_vport_create, \
netdev_vport_destroy, \
netdev_vport_set_config, \
+ netdev_vport_config_equal, \
\
netdev_vport_open, \
netdev_vport_close, \
@@ -933,19 +980,19 @@ netdev_vport_register(void)
static const struct vport_class vport_classes[] = {
{ ODP_VPORT_TYPE_GRE,
{ "gre", VPORT_FUNCTIONS(netdev_vport_get_status) },
- parse_tunnel_config, unparse_tunnel_config },
+ parse_tunnel_config, unparse_tunnel_config, NULL },
{ ODP_VPORT_TYPE_GRE,
{ "ipsec_gre", VPORT_FUNCTIONS(netdev_vport_get_status) },
- parse_tunnel_config, unparse_tunnel_config },
+ parse_tunnel_config, unparse_tunnel_config, config_equal_ipsec },
{ ODP_VPORT_TYPE_CAPWAP,
{ "capwap", VPORT_FUNCTIONS(netdev_vport_get_status) },
- parse_tunnel_config, unparse_tunnel_config },
+ parse_tunnel_config, unparse_tunnel_config, NULL },
{ ODP_VPORT_TYPE_PATCH,
{ "patch", VPORT_FUNCTIONS(NULL) },
- parse_patch_config, unparse_patch_config }
+ parse_patch_config, unparse_patch_config, NULL }
};
int i;
diff --git a/lib/netdev.c b/lib/netdev.c
index 1f0b764..b8592c1 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -243,7 +243,7 @@ netdev_open(struct netdev_options *options, struct netdev **netdevp)
assert(netdev_dev->netdev_class == class);
} else if (!shash_is_empty(options->args) &&
- !smap_equal(&netdev_dev->args, options->args)) {
+ !netdev_dev_args_equal(netdev_dev, options->args)) {
VLOG_WARN("%s: attempted to open already open netdev with "
"different arguments", options->name);
@@ -289,7 +289,7 @@ netdev_set_config(struct netdev *netdev, const struct shash *args)
}
if (netdev_dev->netdev_class->set_config) {
- if (!smap_equal(&netdev_dev->args, args)) {
+ if (!netdev_dev_args_equal(netdev_dev, args)) {
update_device_args(netdev_dev, args);
return netdev_dev->netdev_class->set_config(netdev_dev, args);
}
@@ -1382,6 +1382,19 @@ netdev_dev_get_devices(const struct netdev_class *netdev_class,
}
}
+/* Returns true if 'args' is equivalent to the "args" field in
+ * 'netdev_dev', otherwise false. */
+bool
+netdev_dev_args_equal(const struct netdev_dev *netdev_dev,
+ const struct shash *args)
+{
+ if (netdev_dev->netdev_class->config_equal) {
+ return netdev_dev->netdev_class->config_equal(netdev_dev, args);
+ } else {
+ return smap_equal(&netdev_dev->args, args);
+ }
+}
+
/* Initializes 'netdev' as a instance of the netdev_dev.
*
* This function adds 'netdev' to a netdev-owned linked list, so it is very
--
1.7.1
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