[ovs-dev] [PATCH 1/3] datapath: Add genl_exec().
Pravin B Shelar
pshelar at nicira.com
Thu Dec 22 04:28:13 UTC 2011
Resending this patch as net-namespace patches depends on it.
--8<--------------------------cut here-------------------------->8-
genl_lock is not exported from older kernel. Following patch add
genl_exec() which can run any function (passed as arg) with
genl_lock held.
Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
---
acinclude.m4 | 2 +
datapath/datapath.c | 9 ++-
datapath/linux/compat/genetlink.inc | 126 +++++++++++++++++++++++++
datapath/linux/compat/include/linux/skbuff.h | 6 +
datapath/linux/compat/include/net/genetlink.h | 6 +
5 files changed, 148 insertions(+), 1 deletions(-)
diff --git a/acinclude.m4 b/acinclude.m4
index 648132a..4c1b065 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -230,6 +230,8 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
[OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
[skb_copy_from_linear_data_offset])
+ OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
+ [skb_reset_tail_pointer])
OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],
[OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
diff --git a/datapath/datapath.c b/datapath/datapath.c
index c86c20b..025d932 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -2049,10 +2049,14 @@ static int __init dp_init(void)
pr_info("Open vSwitch switching datapath %s, built "__DATE__" "__TIME__"\n",
VERSION BUILDNR);
- err = ovs_tnl_init();
+ err = genl_exec_init();
if (err)
goto error;
+ err = ovs_tnl_init();
+ if (err)
+ goto error_genl_exec;
+
err = ovs_flow_init();
if (err)
goto error_tnl_exit;
@@ -2079,6 +2083,8 @@ error_flow_exit:
ovs_flow_exit();
error_tnl_exit:
ovs_tnl_exit();
+error_genl_exec:
+ genl_exec_exit();
error:
return err;
}
@@ -2091,6 +2097,7 @@ static void dp_cleanup(void)
ovs_vport_exit();
ovs_flow_exit();
ovs_tnl_exit();
+ genl_exec_exit();
}
module_init(dp_init);
diff --git a/datapath/linux/compat/genetlink.inc b/datapath/linux/compat/genetlink.inc
index bf96980..1301006 100644
--- a/datapath/linux/compat/genetlink.inc
+++ b/datapath/linux/compat/genetlink.inc
@@ -146,3 +146,129 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
{
}
#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35)
+
+static DEFINE_MUTEX(genl_exec_lock);
+
+static genl_exec_func_t genl_exec_function;
+static int genl_exec_function_ret;
+static void *genl_exec_data;
+static struct completion done;
+
+
+static int genl_exec_cmd(struct sk_buff *dummy, struct genl_info *dummy2)
+{
+ genl_exec_function_ret = genl_exec_function(genl_exec_data);
+ complete(&done);
+ return 0;
+}
+
+enum exec_cmd {
+ GENL_EXEC_UNSPEC,
+ GENL_EXEC_RUN,
+};
+
+static struct genl_family genl_exec_family = {
+ .id = GENL_ID_GENERATE,
+ .name = "ovs_genl_exec",
+ .version = 1,
+};
+
+static struct genl_ops genl_exec_ops[] = {
+ {
+ .cmd = GENL_EXEC_RUN,
+ .doit = genl_exec_cmd,
+ .flags = CAP_NET_ADMIN,
+ },
+};
+
+static struct sk_buff *genlmsg_skb;
+
+int genl_exec_init(void)
+{
+ int err;
+
+ err = genl_register_family_with_ops(&genl_exec_family,
+ genl_exec_ops,
+ ARRAY_SIZE(genl_exec_ops));
+
+ if (err)
+ return err;
+
+ genlmsg_skb = genlmsg_new( NLMSG_HDRLEN, GFP_KERNEL);
+ if (!genlmsg_skb) {
+ genl_unregister_family(&genl_exec_family);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void genl_exec_exit(void)
+{
+ genl_unregister_family(&genl_exec_family);
+ mutex_lock(&genl_exec_lock);
+ kfree_skb(genlmsg_skb);
+ genlmsg_skb = NULL;
+ mutex_unlock(&genl_exec_lock);
+}
+
+/* genl_lock() is not exported from older kernel.
+ * Following function allows any function to be executed with
+ * genl_mutex held. */
+
+int genl_exec(genl_exec_func_t func, void *data)
+{
+ int ret;
+ struct nlmsghdr *nlh;
+
+ mutex_lock(&genl_exec_lock);
+ if (!genlmsg_skb) {
+ ret = -ESHUTDOWN;
+ goto out;
+ }
+
+ skb_get(genlmsg_skb);
+
+ nlh = genlmsg_put(genlmsg_skb, 0, 0, &genl_exec_family, NLM_F_REQUEST, GENL_EXEC_RUN);
+ genl_exec_function = func;
+ genl_exec_data = data;
+ init_completion(&done);
+
+ ret = genlmsg_unicast(&init_net, genlmsg_skb, 0);
+ if (!ret) {
+ wait_for_completion(&done);
+ ret = genl_exec_function_ret;
+ } else
+ printk(KERN_ERR "[%s] Msg send error %d\n",__func__, ret);
+
+ genlmsg_skb->data = genlmsg_skb->head;
+ skb_reset_tail_pointer(genlmsg_skb);
+
+out:
+ mutex_unlock(&genl_exec_lock);
+
+ return ret;
+}
+
+#else
+
+int genl_exec(genl_exec_func_t func, void *data)
+{
+ int ret;
+
+ genl_lock();
+ ret = func(data);
+ genl_unlock();
+ return ret;
+}
+
+int genl_exec_init(void)
+{
+ return 0;
+}
+
+void genl_exec_exit(void)
+{
+}
+#endif
diff --git a/datapath/linux/compat/include/linux/skbuff.h b/datapath/linux/compat/include/linux/skbuff.h
index 96d8012..01e524e 100644
--- a/datapath/linux/compat/include/linux/skbuff.h
+++ b/datapath/linux/compat/include/linux/skbuff.h
@@ -34,6 +34,12 @@ static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
#endif /* !HAVE_SKB_COPY_FROM_LINEAR_DATA_OFFSET */
+#ifndef HAVE_SKB_RESET_TAIL_POINTER
+static inline void skb_reset_tail_pointer(struct sk_buff *skb)
+{
+ skb->tail = skb->data;
+}
+#endif
/*
* The networking layer reserves some headroom in skb data (via
* dev_alloc_skb). This is used to avoid having to reallocate skb data when
diff --git a/datapath/linux/compat/include/net/genetlink.h b/datapath/linux/compat/include/net/genetlink.h
index a1ff7c1..1bbb559 100644
--- a/datapath/linux/compat/include/net/genetlink.h
+++ b/datapath/linux/compat/include/net/genetlink.h
@@ -170,4 +170,10 @@ static inline struct net *genl_info_net(struct genl_info *info)
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,32)
#define genlmsg_unicast(ignore_net, skb, pid) genlmsg_unicast(skb, pid)
#endif
+
+typedef int (*genl_exec_func_t)(void *data);
+int genl_exec(genl_exec_func_t func, void *data);
+int genl_exec_init(void);
+void genl_exec_exit(void);
+
#endif /* genetlink.h */
--
1.7.1
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