diff mbox

[12/24] net, diet: Make rtnetlink optional

Message ID 1399328773-6531-13-git-send-email-andi@firstfloor.org
State RFC, archived
Delegated to: David Miller
Headers show

Commit Message

Andi Kleen May 5, 2014, 10:26 p.m. UTC 
From: Andi Kleen <ak@linux.intel.com>

Small systems can use ioctl/ifconfig for routing and
interface configuration. Make rtnetlink optional
This saves ~29k without LTO, more with LTO.

   text    data     bss     dec     hex filename
 483545   19371   13480  516396   7e12c net/built-in.o-with-rtnetlink
 454365   19275   12936  486576   76cb0 net/built-in.o-wo-rtnetlink

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 include/linux/rtnetlink.h | 56 +++++++++++++++++++++++++++++++++++++++++------
 include/net/rtnetlink.h   | 35 +++++++++++++++++++++++++++++
 net/Kconfig               |  8 +++++++
 net/core/Makefile         |  3 ++-
 net/ipv4/fib_frontend.c   |  7 ++++++
 net/ipv4/fib_lookup.h     | 12 ++++++++++
 net/ipv4/fib_semantics.c  |  4 ++++
 7 files changed, 117 insertions(+), 8 deletions(-)

Comments

David Miller May 6, 2014, 3:08 a.m. UTC | #1 
From: Andi Kleen <andi@firstfloor.org>
Date: Mon,  5 May 2014 15:26:01 -0700

> From: Andi Kleen <ak@linux.intel.com>
> 
> Small systems can use ioctl/ifconfig for routing and
> interface configuration. Make rtnetlink optional
> This saves ~29k without LTO, more with LTO.
> 
>    text    data     bss     dec     hex filename
>  483545   19371   13480  516396   7e12c net/built-in.o-with-rtnetlink
>  454365   19275   12936  486576   76cb0 net/built-in.o-wo-rtnetlink
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Andi, I've had about enough with this patch series.

We have moved several tools to only use netlink because it's
the only extensible facility, and we are not looking back.

The moment one of these "small" systems, or whatever you want to call
it, tries to use any feature added to device configuration in the last
20 years ioctl doesn't cut it.
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Andi Kleen May 6, 2014, 3:11 a.m. UTC | #2 
> The moment one of these "small" systems, or whatever you want to call
> it, tries to use any feature added to device configuration in the last
> 20 years ioctl doesn't cut it.

They will simply not use all that complexity ever, 400k is simply prohibitive
with 2MB.

If you want to keep netlink what would you remove instead?

-Andi
diff mbox

Patch

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 8e3e66a..e876aa2 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -7,15 +7,32 @@ 
 #include <uapi/linux/rtnetlink.h>
 
 extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
-extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
-extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
-			u32 group, struct nlmsghdr *nlh, gfp_t flags);
-extern void rtnl_set_sk_err(struct net *net, u32 group, int error);
-extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
 extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
 			      u32 id, long expires, u32 error);
 
+#ifdef CONFIG_RTNETLINK
+void rtnl_set_sk_err(struct net *net, u32 group, int error);
+int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
+void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
+			u32 group, struct nlmsghdr *nlh, gfp_t flags);
 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags);
+int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
+#else
+static inline int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid)
+{ return -EIO; }
+
+static inline void
+rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags) {}
+
+static inline void
+rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
+	    u32 group, struct nlmsghdr *nlh, gfp_t flags) {}
+
+static inline int
+rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics) { return -EINVAL; }
+
+static inline void rtnl_set_sk_err(struct net *net, u32 group, int error) {}
+#endif
 
 /* RTNL is used as a global lock for all changes to network configuration  */
 extern void rtnl_lock(void);
@@ -59,7 +76,12 @@  static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
 
 extern struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);
 
+#ifdef CONFIG_RTNETLINK
 extern void rtnetlink_init(void);
+#else
+static inline void rtnetlink_init(void) {}
+#endif
+
 extern void __rtnl_unlock(void);
 
 #define ASSERT_RTNL() do { \
@@ -70,6 +92,7 @@  extern void __rtnl_unlock(void);
 	} \
 } while(0)
 
+#ifdef CONFIG_RTNETLINK
 extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
 			     struct netlink_callback *cb,
 			     struct net_device *dev,
@@ -79,11 +102,30 @@  extern int ndo_dflt_fdb_add(struct ndmsg *ndm,
 			    struct net_device *dev,
 			    const unsigned char *addr,
 			     u16 flags);
+extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
+				   struct net_device *dev, u16 mode);
 extern int ndo_dflt_fdb_del(struct ndmsg *ndm,
 			    struct nlattr *tb[],
 			    struct net_device *dev,
 			    const unsigned char *addr);
 
-extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
-				   struct net_device *dev, u16 mode);
+#else
+static inline int ndo_dflt_fdb_dump(struct sk_buff *skb,
+			     struct netlink_callback *cb,
+			     struct net_device *dev,
+			     int idx) { return -EINVAL; }
+static inline int ndo_dflt_fdb_add(struct ndmsg *ndm,
+			    struct nlattr *tb[],
+			    struct net_device *dev,
+			    const unsigned char *addr,
+			     u16 flags) { return -EINVAL; }
+static inline int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
+				   struct net_device *dev, u16 mode)
+{ return -EINVAL; }
+static inline int ndo_dflt_fdb_del(struct ndmsg *ndm,
+			    struct nlattr *tb[],
+			    struct net_device *dev,
+			    const unsigned char *addr)
+{ return -EINVAL; }
+#endif	/* !CONFIG_RTNETLINK */
 #endif	/* __LINUX_RTNETLINK_H */
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 72240e5..859078b 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -8,12 +8,23 @@  typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *);
 typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);
 typedef u16 (*rtnl_calcit_func)(struct sk_buff *, struct nlmsghdr *);
 
+#ifdef CONFIG_RTNETLINK
 int __rtnl_register(int protocol, int msgtype,
 		    rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func);
 void rtnl_register(int protocol, int msgtype,
 		   rtnl_doit_func, rtnl_dumpit_func, rtnl_calcit_func);
 int rtnl_unregister(int protocol, int msgtype);
 void rtnl_unregister_all(int protocol);
+#else
+static inline int __rtnl_register(int protocol, int msgtype,
+		    rtnl_doit_func d, rtnl_dumpit_func du, rtnl_calcit_func c)
+{ return -EINVAL; }
+static inline void rtnl_register(int protocol, int msgtype,
+		   rtnl_doit_func d, rtnl_dumpit_func du, rtnl_calcit_func c)
+{ }
+static inline int rtnl_unregister(int protocol, int msgtype) { return 0; }
+static inline void rtnl_unregister_all(int protocol) {}
+#endif
 
 static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
 {
@@ -95,11 +106,25 @@  struct rtnl_link_ops {
 						   const struct net_device *slave_dev);
 };
 
+#ifdef CONFIG_RTNETLINK
 int __rtnl_link_register(struct rtnl_link_ops *ops);
 void __rtnl_link_unregister(struct rtnl_link_ops *ops);
 
 int rtnl_link_register(struct rtnl_link_ops *ops);
 void rtnl_link_unregister(struct rtnl_link_ops *ops);
+#else
+/* Return 0 to make the respective init functions not error out.
+ * We assume the subsystems are still somewhat useful even without
+ * rtnetlink.
+ */
+static inline int __rtnl_link_register(struct rtnl_link_ops *ops)
+{ return 0; }
+static inline void __rtnl_link_unregister(struct rtnl_link_ops *ops) {}
+
+static inline int rtnl_link_register(struct rtnl_link_ops *ops)
+{ return 0; }
+static inline void rtnl_link_unregister(struct rtnl_link_ops *ops) {}
+#endif
 
 /**
  * 	struct rtnl_af_ops - rtnetlink address family operations
@@ -129,10 +154,20 @@  struct rtnl_af_ops {
 					       const struct nlattr *attr);
 };
 
+#ifdef CONFIG_RTNETLINK
+int __rtnl_af_register(struct rtnl_af_ops *ops);
 void __rtnl_af_unregister(struct rtnl_af_ops *ops);
 
 void rtnl_af_register(struct rtnl_af_ops *ops);
 void rtnl_af_unregister(struct rtnl_af_ops *ops);
+#else
+static inline int __rtnl_af_register(struct rtnl_af_ops *ops)
+{ return -EINVAL; }
+static inline void __rtnl_af_unregister(struct rtnl_af_ops *ops) {}
+
+static inline int rtnl_af_register(struct rtnl_af_ops *ops) { return -EINVAL; }
+static inline void rtnl_af_unregister(struct rtnl_af_ops *ops) {}
+#endif
 
 struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
 struct net_device *rtnl_create_link(struct net *net, char *ifname,
diff --git a/net/Kconfig b/net/Kconfig
index 82a5764..f5196ba 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -24,6 +24,14 @@  menuconfig NET
 
 if NET
 
+config RTNETLINK
+       bool "rtnetlink"
+       default y
+       help
+         Enable rtnetlink to configure routing and related setups.
+	 This is needed for most modern configuration
+	 tools, but old ifconfig can do without it.
+
 config WANT_COMPAT_NETLINK_MESSAGES
 	bool
 	help
diff --git a/net/core/Makefile b/net/core/Makefile
index e05bd9c..50d4850 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -9,11 +9,12 @@  obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \
 obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
 
 obj-y		     += dev.o dev_addr_lists.o dst.o netevent.o \
-			neighbour.o rtnetlink.o utils.o link_watch.o \
+			neighbour.o utils.o link_watch.o \
 			sock_diag.o dev_ioctl.o
 
 obj-$(CONFIG_XFRM) += flow.o
 obj-y += net-sysfs.o
+obj-$(CONFIG_RTNETLINK) += rtnetlink.o
 obj-$(CONFIG_NET_ETHTOOL) += ethtool.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
 obj-$(CONFIG_NET_PKTGEN) += pktgen.o
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 255aa99..3221b0e 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -917,6 +917,9 @@  void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 #undef BRD1_OK
 }
 
+#ifdef CONFIG_RTNETLINK
+/* Isn't really rtnetlink, but close enough for this CONFIG. */
+
 static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
 {
 
@@ -994,6 +997,10 @@  static void nl_fib_lookup_exit(struct net *net)
 	netlink_kernel_release(net->ipv4.fibnl);
 	net->ipv4.fibnl = NULL;
 }
+#else
+static inline void nl_fib_lookup_exit(struct net *net) {}
+static inline int nl_fib_lookup_init(struct net *net) { return 0; }
+#endif
 
 static void fib_disable_ip(struct net_device *dev, int force)
 {
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index 1e4f660..ec29c81 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -27,11 +27,23 @@  static inline void fib_alias_accessed(struct fib_alias *fa)
 void fib_release_info(struct fib_info *);
 struct fib_info *fib_create_info(struct fib_config *cfg);
 int fib_nh_match(struct fib_config *cfg, struct fib_info *fi);
+#ifdef CONFIG_RTNETLINK
 int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event, u32 tb_id,
 		  u8 type, __be32 dst, int dst_len, u8 tos, struct fib_info *fi,
 		  unsigned int);
 void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, int dst_len,
 	       u32 tb_id, const struct nl_info *info, unsigned int nlm_flags);
+#else
+static inline int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq,
+		  int event, u32 tb_id,
+		  u8 type, __be32 dst, int dst_len, u8 tos,
+		  struct fib_info *fi,
+		  unsigned int f) { return -EINVAL; }
+static inline void
+rtmsg_fib(int event, __be32 key, struct fib_alias *fa, int dst_len,
+	       u32 tb_id, const struct nl_info *info, unsigned int nlm_flags)
+{}
+#endif
 struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio);
 
 static inline void fib_result_assign(struct fib_result *res,
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c3d4e4d..75be44d 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -356,6 +356,7 @@  int ip_fib_check_default(__be32 gw, struct net_device *dev)
 	return -1;
 }
 
+#ifdef CONFIG_RTNETLINK
 static inline size_t fib_nlmsg_size(struct fib_info *fi)
 {
 	size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
@@ -411,6 +412,7 @@  errout:
 	if (err < 0)
 		rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
 }
+#endif
 
 /* Return the first fib alias matching TOS with
  * priority less than or equal to PRIO.
@@ -998,6 +1000,7 @@  failure:
 	return ERR_PTR(err);
 }
 
+#ifdef CONFIG_RTNETLINK
 int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 		  u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
 		  struct fib_info *fi, unsigned int flags)
@@ -1089,6 +1092,7 @@  nla_put_failure:
 	nlmsg_cancel(skb, nlh);
 	return -EMSGSIZE;
 }
+#endif
 
 /*
  * Update FIB if: