This patchs adds the CONFIG_IGMP option which allows to remove support
for the Internet Group Management Protocol, used in
multicast. Multicast is not necessarly used by applications,
particularly on embedded devices. As this is a size-reduction option,
it depends on CONFIG_EMBEDDED. It allows to save ~10 kilobytes of
kernel code/data:
text data bss dec hex filename
1718857 143672 221184 2083713 1fcb81 vmlinux
1708838 143640 221184 2073662 1fa43e vmlinux.new
-10019 -32 0 -10051 -2743 +/-
This patch has been originally written by Matt Mackall
<mpm@xxxxxxxxxxx>, and is part of the Linux Tiny project.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: davem@xxxxxxxxxxxxx
Cc: mpm@xxxxxxxxxxx
Cc: akpm@xxxxxxxxxxxxxxxxxxxx
---
include/linux/igmp.h | 20 ++++++++++++++++++++
init/Kconfig | 8 ++++++++
net/ipv4/Makefile | 3 ++-
net/ipv4/af_inet.c | 2 --
net/ipv4/ip_sockglue.c | 4 ++++
net/ipv4/sysctl_net_ipv4.c | 2 ++
6 files changed, 36 insertions(+), 3 deletions(-)
Index: linuxdev/include/linux/igmp.h
===================================================================
--- linuxdev.orig/include/linux/igmp.h
+++ linuxdev/include/linux/igmp.h
@@ -215,6 +215,7 @@
#define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)
#define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)
+#ifdef CONFIG_IGMP
extern int ip_check_mc(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);
extern int igmp_rcv(struct sk_buff *);
extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);
@@ -235,6 +236,25 @@
extern void ip_mc_dec_group(struct in_device *in_dev, __be32 addr);
extern void ip_mc_inc_group(struct in_device *in_dev, __be32 addr);
extern void ip_mc_rejoin_group(struct ip_mc_list *im);
+#else /* !CONFIG_IGMP */
+#define ip_check_mc(a, b, c, d) (0)
+#define igmp_rcv(a) (0)
+#define ip_mc_join_group(a, b) (0)
+#define ip_mc_leave_group(a, b) (0)
+#define ip_mc_drop_socket(a)
+#define ip_mc_source(a, b, c, d, e) (0)
+#define ip_mc_msfilter(a, b, c) (0)
+#define ip_mc_msfget(a, b, c, d) (0)
+#define ip_mc_gsfget(a, b, c, d) (0)
+#define ip_mc_sf_allow(a, b, c, d) (0)
+#define ip_mc_init_dev(a)
+#define ip_mc_destroy_dev(a)
+#define ip_mc_up(a)
+#define ip_mc_down(a)
+#define ip_mc_dec_group(a)
+#define ip_mc_inc_group(a)
+#define ip_mc_rejoin_group(a)
+#endif /* CONFIG_IGMP */
#endif
#endif
Index: linuxdev/init/Kconfig
===================================================================
--- linuxdev.orig/init/Kconfig
+++ linuxdev/init/Kconfig
@@ -748,6 +748,14 @@
Disabling this option removes support for configuring
ethernet device features via ethtool. Saves about 6k.
+config IGMP
+ depends on INET
+ bool "Enable IGMP support" if EMBEDDED && !IP_MULTICAST
+ default y
+ help
+ Disabling this option removes support for the Internet group
+ management protocol, used for multicast. Saves about 10k.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
Index: linuxdev/net/ipv4/Makefile
===================================================================
--- linuxdev.orig/net/ipv4/Makefile
+++ linuxdev/net/ipv4/Makefile
@@ -9,13 +9,14 @@
tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
tcp_minisocks.o tcp_cong.o \
datagram.o raw.o udp.o udplite.o \
- arp.o icmp.o devinet.o af_inet.o igmp.o \
+ arp.o icmp.o devinet.o af_inet.o \
fib_frontend.o fib_semantics.o \
inet_fragment.o
obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o
obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o
+obj-$(CONFIG_IGMP) += igmp.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
obj-$(CONFIG_IP_MROUTE) += ipmr.o
Index: linuxdev/net/ipv4/af_inet.c
===================================================================
--- linuxdev.orig/net/ipv4/af_inet.c
+++ linuxdev/net/ipv4/af_inet.c
@@ -115,8 +115,6 @@
#include <linux/mroute.h>
#endif
-extern void ip_mc_drop_socket(struct sock *sk);
-
/* The inetsw table contains everything that inet_create needs to
* build a new socket.
*/
Index: linuxdev/net/ipv4/ip_sockglue.c
===================================================================
--- linuxdev.orig/net/ipv4/ip_sockglue.c
+++ linuxdev/net/ipv4/ip_sockglue.c
@@ -640,6 +640,7 @@
err = ip_mc_leave_group(sk, &mreq);
break;
}
+#ifdef CONFIG_IGMP
case IP_MSFILTER:
{
extern int sysctl_igmp_max_msf;
@@ -677,6 +678,7 @@
kfree(msf);
break;
}
+#endif
case IP_BLOCK_SOURCE:
case IP_UNBLOCK_SOURCE:
case IP_ADD_SOURCE_MEMBERSHIP:
@@ -794,6 +796,7 @@
greqs.gsr_interface);
break;
}
+#ifdef CONFIG_IGMP
case MCAST_MSFILTER:
{
extern int sysctl_igmp_max_msf;
@@ -860,6 +863,7 @@
kfree(gsf);
break;
}
+#endif
case IP_ROUTER_ALERT:
err = ip_ra_control(sk, val ? 1 : 0, NULL);
break;
Index: linuxdev/net/ipv4/sysctl_net_ipv4.c
===================================================================
--- linuxdev.orig/net/ipv4/sysctl_net_ipv4.c
+++ linuxdev/net/ipv4/sysctl_net_ipv4.c
@@ -412,6 +412,7 @@
},
#endif
+#ifdef CONFIG_IGMP
{
.ctl_name = NET_IPV4_IGMP_MAX_MSF,
.procname = "igmp_max_msf",
@@ -420,6 +421,7 @@
.mode = 0644,
.proc_handler = &proc_dointvec
},
+#endif
{
.ctl_name = NET_IPV4_INET_PEER_THRESHOLD,
.procname = "inet_peer_threshold",
--
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com
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