[PATCH v2] ipv4: Make IP_MULTICAST_ALL and IP_MSFILTER work on raw sockets

[PATCH v2] ipv4: Make IP_MULTICAST_ALL and IP_MSFILTER work on raw sockets

[Quentin Armitage]

Currently, although IP_MULTICAST_ALL and IP_MSFILTER ioctl calls succeed on
raw sockets, there is no code to implement the functionality on received
packets; it is only implemented for UDP sockets. The raw(7) man page states:
"In addition, all ip(7) IPPROTO_IP socket options valid for datagram sockets
are supported", which implies these ioctls should work on raw sockets.

To fix this, add a call to ip_mc_sf_allow on raw sockets.

This should not break any existing code, since the current position of
not calling ip_mc_sf_filter makes it behave as if neither the IP_MULTICAST_ALL
nor the IP_MSFILTER ioctl had been called. Adding the call to ip_mc_sf_allow
will therefore maintain the current behaviour so long as IP_MULTICAST_ALL and
IP_MSFILTER ioctls are not called. Any code that currently is calling
IP_MULTICAST_ALL or IP_MSFILTER ioctls on raw sockets presumably is wanting
the filter to be applied, although no filtering will currently be occurring.

Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>
---
v2: * Fixed subject line
---
 net/ipv4/raw.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 2c65160..2e1628c 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -58,6 +58,7 @@
 #include <linux/in_route.h>
 #include <linux/route.h>
 #include <linux/skbuff.h>
+#include <linux/igmp.h>
 #include <net/net_namespace.h>
 #include <net/dst.h>
 #include <net/sock.h>
@@ -174,7 +175,9 @@ static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
 
        while (sk) {
                delivered = 1;
-               if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
+               if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) &&
+                   ip_mc_sf_allow(sk, iph->daddr, iph->saddr,
+                                  skb->dev->ifindex)) {
                        struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
 
                        /* Not releasing hash table! */
-- 
1.7.7.6

Re: [PATCH v2] ipv4: Make IP_MULTICAST_ALL and IP_MSFILTER work on raw sockets

[David Miller]

From: Quentin Armitage <quentin@armitage.org.uk>
Date: Tue, 22 Jul 2014 09:10:10 +0100

> Currently, although IP_MULTICAST_ALL and IP_MSFILTER ioctl calls succeed on
> raw sockets, there is no code to implement the functionality on received
> packets; it is only implemented for UDP sockets. The raw(7) man page states:
> "In addition, all ip(7) IPPROTO_IP socket options valid for datagram sockets
> are supported", which implies these ioctls should work on raw sockets.
> 
> To fix this, add a call to ip_mc_sf_allow on raw sockets.
> 
> This should not break any existing code, since the current position of
> not calling ip_mc_sf_filter makes it behave as if neither the IP_MULTICAST_ALL
> nor the IP_MSFILTER ioctl had been called. Adding the call to ip_mc_sf_allow
> will therefore maintain the current behaviour so long as IP_MULTICAST_ALL and
> IP_MSFILTER ioctls are not called. Any code that currently is calling
> IP_MULTICAST_ALL or IP_MSFILTER ioctls on raw sockets presumably is wanting
> the filter to be applied, although no filtering will currently be occurring.
> 
> Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>
> ---
> v2: * Fixed subject line

Your email client has corrupted the patch, transforming TAB characters
into spaces, amongst other things.

Please correct this and resubmit your patch.