ipv4: Sanitize and simplify ip_route_{connect,newports}()
These functions are used together as a unit for route resolution
during connect(). They address the chicken-and-egg problem that
exists when ports need to be allocated during connect() processing,
yet such port allocations require addressing information from the
routing code.
It's currently more heavy handed than it needs to be, and in
particular we allocate and initialize a flow object twice.
Let the callers provide the on-stack flow object. That way we only
need to initialize it once in the ip_route_connect() call.
Later, if ip_route_newports() needs to do anything, it re-uses that
flow object as-is except for the ports which it updates before the
route re-lookup.
Also, describe why this set of facilities are needed and how it works
in a big comment.
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index ae451c6..b92ab65 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -40,12 +40,13 @@
int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
+ const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
struct inet_sock *inet = inet_sk(sk);
struct dccp_sock *dp = dccp_sk(sk);
- const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
__be16 orig_sport, orig_dport;
- struct rtable *rt;
__be32 daddr, nexthop;
+ struct flowi4 fl4;
+ struct rtable *rt;
int err;
dp->dccps_role = DCCP_ROLE_CLIENT;
@@ -65,7 +66,7 @@
orig_sport = inet->inet_sport;
orig_dport = usin->sin_port;
- rt = ip_route_connect(nexthop, inet->inet_saddr,
+ rt = ip_route_connect(&fl4, nexthop, inet->inet_saddr,
RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
IPPROTO_DCCP,
orig_sport, orig_dport, sk, true);
@@ -101,8 +102,7 @@
if (err != 0)
goto failure;
- rt = ip_route_newports(rt, IPPROTO_DCCP,
- orig_sport, orig_dport,
+ rt = ip_route_newports(&fl4, rt, orig_sport, orig_dport,
inet->inet_sport, inet->inet_dport, sk);
if (IS_ERR(rt)) {
rt = NULL;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index cae75ef..0413af3 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1103,6 +1103,7 @@
struct inet_sock *inet = inet_sk(sk);
__be32 old_saddr = inet->inet_saddr;
__be32 daddr = inet->inet_daddr;
+ struct flowi4 fl4;
struct rtable *rt;
__be32 new_saddr;
@@ -1110,7 +1111,7 @@
daddr = inet->opt->faddr;
/* Query new route. */
- rt = ip_route_connect(daddr, 0, RT_CONN_FLAGS(sk),
+ rt = ip_route_connect(&fl4, daddr, 0, RT_CONN_FLAGS(sk),
sk->sk_bound_dev_if, sk->sk_protocol,
inet->inet_sport, inet->inet_dport, sk, false);
if (IS_ERR(rt))
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 85bd24c..216ba23 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -24,6 +24,7 @@
{
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
+ struct flowi4 fl4;
struct rtable *rt;
__be32 saddr;
int oif;
@@ -46,7 +47,7 @@
if (!saddr)
saddr = inet->mc_addr;
}
- rt = ip_route_connect(usin->sin_addr.s_addr, saddr,
+ rt = ip_route_connect(&fl4, usin->sin_addr.s_addr, saddr,
RT_CONN_FLAGS(sk), oif,
sk->sk_protocol,
inet->inet_sport, usin->sin_port, sk, true);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index edf18bd..310454c 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -146,12 +146,13 @@
/* This will initiate an outgoing connection. */
int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
+ struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
struct inet_sock *inet = inet_sk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
__be16 orig_sport, orig_dport;
- struct rtable *rt;
__be32 daddr, nexthop;
+ struct flowi4 fl4;
+ struct rtable *rt;
int err;
if (addr_len < sizeof(struct sockaddr_in))
@@ -169,7 +170,7 @@
orig_sport = inet->inet_sport;
orig_dport = usin->sin_port;
- rt = ip_route_connect(nexthop, inet->inet_saddr,
+ rt = ip_route_connect(&fl4, nexthop, inet->inet_saddr,
RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
IPPROTO_TCP,
orig_sport, orig_dport, sk, true);
@@ -236,8 +237,7 @@
if (err)
goto failure;
- rt = ip_route_newports(rt, IPPROTO_TCP,
- orig_sport, orig_dport,
+ rt = ip_route_newports(&fl4, rt, orig_sport, orig_dport,
inet->inet_sport, inet->inet_dport, sk);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index fce9bd3..cc67367 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -296,12 +296,12 @@
static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
- int rc;
- struct inet_sock *inet = inet_sk(sk);
struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
+ struct inet_sock *inet = inet_sk(sk);
+ struct flowi4 fl4;
struct rtable *rt;
__be32 saddr;
- int oif;
+ int oif, rc;
rc = -EINVAL;
if (addr_len < sizeof(*lsa))
@@ -320,7 +320,7 @@
if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
goto out;
- rt = ip_route_connect(lsa->l2tp_addr.s_addr, saddr,
+ rt = ip_route_connect(&fl4, lsa->l2tp_addr.s_addr, saddr,
RT_CONN_FLAGS(sk), oif,
IPPROTO_L2TP,
0, 0, sk, true);