[PATCH] ipv4/raw: support binding to nonlocal addresses

From: Riccardo Paolo Bestetti
Date: Sat Mar 20 2021 - 20:25:36 EST


Add support to inet raw sockets for binding to nonlocal addresses
through the IP_FREEBIND and IP_TRANSPARENT socket options, as well as
the ipv4.ip_nonlocal_bind kernel parameter.

Signed-off-by: Riccardo Paolo Bestetti <pbl@xxxxxxxxx>
---
net/ipv4/raw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 50a73178d63a..734c0332b54b 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -717,6 +717,7 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
+ struct net *net = sock_net(sk);
u32 tb_id = RT_TABLE_LOCAL;
int ret = -EINVAL;
int chk_addr_ret;
@@ -732,7 +733,8 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
tb_id);

ret = -EADDRNOTAVAIL;
- if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
+ if (!inet_can_nonlocal_bind(net, inet) &&
+ addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
goto out;
inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
--
2.31.0