Merge branch 'ipv6-udp-set-dst-cache-for-a-connected-sk-if-current-not-valid'

Alexey Kodanev says:

====================
ipv6: udp: set dst cache for a connected sk if current not valid

A new RTF_CACHE route can be created with the socket's dst cache
update between the below calls in udpv6_sendmsg(), when datagram
sending results to ICMPV6_PKT_TOOBIG error:

   dst = ip6_sk_dst_lookup_flow(...)
   ...
release_dst:
    if (dst) {
        if (connected) {
            ip6_dst_store(sk, dst)

Therefore, the new socket's dst cache reset to the old one on
"release_dst:".

The first three patches prepare the code to store dst cache
with ip6_sk_dst_lookup_flow():

  * the first patch adds ip6_sk_dst_store_flow() function with
    commonly used source and destiantion addresses checks using
    the flow information.

  * the second patch adds a new argument to ip6_sk_dst_lookup_flow()
    and ability to store dst in the socket's cache. Also, the two
    users of the function are updated without enabling the new
    behavior: pingv6_sendmsg() and udpv6_sendmsg().

  * the third patch makes 'connected' variable in udpv6_sendmsg()
    to be consistent with ip6_sk_dst_store_flow(), changes its type
    from int to bool.

The last patch contains the actual fix that removes sk dst cache
update in the end of udpv6_sendmsg(), and allows to do it in
ip6_sk_dst_lookup_flow().

v6: * use bool type for a new parameter in ip_sk_dst_lookup_flow()
    * add one more patch to convert 'connected' variable in
      udpv6_sendmsg() from int to bool type. If it shouldn't be
      here I will resend it when the net-next is opened.

v5: * relocate ip6_sk_dst_store_flow() to net/ipv6/route.c and
      rename ip6_dst_store_flow() to ip6_sk_dst_store_flow() as
      suggested by Martin

v4: * fix the error in the build of ip_dst_store_flow() reported by
      kbuild test robot due to missing checks for CONFIG_IPV6: add
      new function to ip6_output.c instead of ip6_route.h
    * add 'const' to struct flowi6 in ip6_dst_store_flow()
    * minor commit messages fixes

v3: * instead of moving ip6_dst_store() above udp_v6_send_skb(),
      update socket's dst cache inside ip6_sk_dst_lookup_flow()
      if the current one is invalid
    * the issue not reproduced in 4.1, but starting from 4.2. Add
      one more 'Fixes:' commit that creates new RTF_CACHE route.
      Though, it is also mentioned in the first one
====================

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2018-04-04 11:31:58 -04:00
commit f51ffde927
7 changed files with 43 additions and 37 deletions

View File

@ -214,6 +214,9 @@ static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
#endif
}
void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
const struct flowi6 *fl6);
static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
{
struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);

View File

@ -965,7 +965,8 @@ int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
const struct in6_addr *final_dst);
struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
const struct in6_addr *final_dst);
const struct in6_addr *final_dst,
bool connected);
struct dst_entry *ip6_blackhole_route(struct net *net,
struct dst_entry *orig_dst);

View File

@ -106,14 +106,7 @@ int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
}
}
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
&sk->sk_v6_daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
ip6_sk_dst_store_flow(sk, dst, &fl6);
out:
fl6_sock_release(flowlabel);

View File

@ -1105,23 +1105,32 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
* @sk: socket which provides the dst cache and route info
* @fl6: flow to lookup
* @final_dst: final destination address for ipsec lookup
* @connected: whether @sk is connected or not
*
* This function performs a route lookup on the given flow with the
* possibility of using the cached route in the socket if it is valid.
* It will take the socket dst lock when operating on the dst cache.
* As a result, this function can only be used in process context.
*
* In addition, for a connected socket, cache the dst in the socket
* if the current cache is not valid.
*
* It returns a valid dst pointer on success, or a pointer encoded
* error code.
*/
struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
const struct in6_addr *final_dst)
const struct in6_addr *final_dst,
bool connected)
{
struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
dst = ip6_sk_dst_check(sk, dst, fl6);
if (!dst)
dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
if (dst)
return dst;
dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
if (connected && !IS_ERR(dst))
ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
return dst;
}

View File

@ -121,7 +121,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
ipc6.tclass = np->tclass;
fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr);
dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
if (IS_ERR(dst))
return PTR_ERR(dst);
rt = (struct rt6_info *) dst;

View File

@ -2229,6 +2229,23 @@ void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
}
EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
const struct flowi6 *fl6)
{
#ifdef CONFIG_IPV6_SUBTREES
struct ipv6_pinfo *np = inet6_sk(sk);
#endif
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
&sk->sk_v6_daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
}
/* Handle redirects */
struct ip6rd_flowi {
struct flowi6 fl6;

View File

@ -1116,10 +1116,10 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
struct dst_entry *dst;
struct ipcm6_cookie ipc6;
int addr_len = msg->msg_namelen;
bool connected = false;
int ulen = len;
int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
int err;
int connected = 0;
int is_udplite = IS_UDPLITE(sk);
int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
struct sockcm_cookie sockc;
@ -1241,7 +1241,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
fl6.fl6_dport = inet->inet_dport;
daddr = &sk->sk_v6_daddr;
fl6.flowlabel = np->flow_label;
connected = 1;
connected = true;
}
if (!fl6.flowi6_oif)
@ -1271,7 +1271,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
}
if (!(opt->opt_nflen|opt->opt_flen))
opt = NULL;
connected = 0;
connected = false;
}
if (!opt) {
opt = txopt_get(np);
@ -1293,11 +1293,11 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
final_p = fl6_update_dst(&fl6, opt, &final);
if (final_p)
connected = 0;
connected = false;
if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
fl6.flowi6_oif = np->mcast_oif;
connected = 0;
connected = false;
} else if (!fl6.flowi6_oif)
fl6.flowi6_oif = np->ucast_oif;
@ -1308,7 +1308,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
dst = NULL;
@ -1333,7 +1333,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
err = PTR_ERR(skb);
if (!IS_ERR_OR_NULL(skb))
err = udp_v6_send_skb(skb, &fl6);
goto release_dst;
goto out;
}
lock_sock(sk);
@ -1367,23 +1367,6 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
err = np->recverr ? net_xmit_errno(err) : 0;
release_sock(sk);
release_dst:
if (dst) {
if (connected) {
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
&sk->sk_v6_daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
} else {
dst_release(dst);
}
dst = NULL;
}
out:
dst_release(dst);
fl6_sock_release(flowlabel);