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authorErich E. Hoover <ehoover@mines.edu>2012-02-08 09:11:07 +0000
committerDavid S. Miller <davem@davemloft.net>2012-02-08 15:52:45 -0500
commit76e21053b5bf33a07c76f99d27a74238310e3c71 (patch)
tree70ac2a67be8f19da96896950447567e156975149 /net/ipv4
parent43480aecb1f538d4f6dd8b2c5d2b71fb98659072 (diff)
downloadop-kernel-dev-76e21053b5bf33a07c76f99d27a74238310e3c71.zip
op-kernel-dev-76e21053b5bf33a07c76f99d27a74238310e3c71.tar.gz
ipv4: Implement IP_UNICAST_IF socket option.
The IP_UNICAST_IF feature is needed by the Wine project. This patch implements the feature by setting the outgoing interface in a similar fashion to that of IP_MULTICAST_IF. A separate option is needed to handle this feature since the existing options do not provide all of the characteristics required by IP_UNICAST_IF, a summary is provided below. SO_BINDTODEVICE: * SO_BINDTODEVICE requires administrative privileges, IP_UNICAST_IF does not. From reading some old mailing list articles my understanding is that SO_BINDTODEVICE requires administrative privileges because it can override the administrator's routing settings. * The SO_BINDTODEVICE option restricts both outbound and inbound traffic, IP_UNICAST_IF only impacts outbound traffic. IP_PKTINFO: * Since IP_PKTINFO and IP_UNICAST_IF are independent options, implementing IP_UNICAST_IF with IP_PKTINFO will likely break some applications. * Implementing IP_UNICAST_IF on top of IP_PKTINFO significantly complicates the Wine codebase and reduces the socket performance (doing this requires a lot of extra communication between the "server" and "user" layers). bind(): * bind() does not work on broadcast packets, IP_UNICAST_IF is specifically intended to work with broadcast packets. * Like SO_BINDTODEVICE, bind() restricts both outbound and inbound traffic. Signed-off-by: Erich E. Hoover <ehoover@mines.edu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/ip_sockglue.c33
-rw-r--r--net/ipv4/ping.c3
-rw-r--r--net/ipv4/raw.c3
-rw-r--r--net/ipv4/udp.c3
4 files changed, 39 insertions, 3 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 8aa87c1..9125529 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -469,6 +469,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
(1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
(1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) |
(1<<IP_MINTTL) | (1<<IP_NODEFRAG))) ||
+ optname == IP_UNICAST_IF ||
optname == IP_MULTICAST_TTL ||
optname == IP_MULTICAST_ALL ||
optname == IP_MULTICAST_LOOP ||
@@ -628,6 +629,35 @@ static int do_ip_setsockopt(struct sock *sk, int level,
goto e_inval;
inet->mc_loop = !!val;
break;
+ case IP_UNICAST_IF:
+ {
+ struct net_device *dev = NULL;
+ int ifindex;
+
+ if (optlen != sizeof(int))
+ goto e_inval;
+
+ ifindex = (__force int)ntohl((__force __be32)val);
+ if (ifindex == 0) {
+ inet->uc_index = 0;
+ err = 0;
+ break;
+ }
+
+ dev = dev_get_by_index(sock_net(sk), ifindex);
+ err = -EADDRNOTAVAIL;
+ if (!dev)
+ break;
+ dev_put(dev);
+
+ err = -EINVAL;
+ if (sk->sk_bound_dev_if)
+ break;
+
+ inet->uc_index = ifindex;
+ err = 0;
+ break;
+ }
case IP_MULTICAST_IF:
{
struct ip_mreqn mreq;
@@ -1178,6 +1208,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
case IP_MULTICAST_LOOP:
val = inet->mc_loop;
break;
+ case IP_UNICAST_IF:
+ val = (__force int)htonl((__u32) inet->uc_index);
+ break;
case IP_MULTICAST_IF:
{
struct in_addr addr;
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index aea5a19..cfc82cf 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -556,7 +556,8 @@ static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
- }
+ } else if (!ipc.oif)
+ ipc.oif = inet->uc_index;
flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
RT_SCOPE_UNIVERSE, sk->sk_protocol,
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 3ccda5a..ab46630 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -563,7 +563,8 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
- }
+ } else if (!ipc.oif)
+ ipc.oif = inet->uc_index;
flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
RT_SCOPE_UNIVERSE,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 5d075b5..cd99f1a 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -917,7 +917,8 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (!saddr)
saddr = inet->mc_addr;
connected = 0;
- }
+ } else if (!ipc.oif)
+ ipc.oif = inet->uc_index;
if (connected)
rt = (struct rtable *)sk_dst_check(sk, 0);
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