[Devel] Re: [PATCH 2/2] netns: Add network namespace argument in rt6_fill_node() and ipv6_dev_get_saddr()
Daniel Lezcano
dlezcano at fr.ibm.com
Sat Aug 16 15:47:12 PDT 2008
Brian Haley wrote:
> Add network namespace argument to rt6_fill_node() and
> ipv6_dev_get_saddr(). This required adding a namespace pointer in the
> IPv6 fib dump callback routine.
>
> -Brian
>
> Signed-off-by: Brian Haley <brian.haley at hp.com>
> ---
This patch is to fix a kernel panic in ipv6_dev_get_saddr.
That happens because the dev parameter can be null and we try to
dereference dev->nd_net, right ?
The approach looks correct except with the network namespace passed as
parameter, it must never be NULL.
> diff --git a/include/net/addrconf.h b/include/net/addrconf.h
> index 06b2814..c216de5 100644
> --- a/include/net/addrconf.h
> +++ b/include/net/addrconf.h
> @@ -80,7 +80,8 @@ extern struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net,
> struct net_device *dev,
> int strict);
>
> -extern int ipv6_dev_get_saddr(struct net_device *dev,
> +extern int ipv6_dev_get_saddr(struct net *net,
> + struct net_device *dev,
> const struct in6_addr *daddr,
> unsigned int srcprefs,
> struct in6_addr *saddr);
> diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
> index bc391ba..5f53db7 100644
> --- a/include/net/ip6_route.h
> +++ b/include/net/ip6_route.h
> @@ -107,6 +107,7 @@ struct rt6_rtnl_dump_arg
> {
> struct sk_buff *skb;
> struct netlink_callback *cb;
> + struct net *net;
> };
>
> extern int rt6_dump_route(struct rt6_info *rt, void *p_arg);
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index a7842c5..dea420a 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -1106,17 +1106,19 @@ out:
> return ret;
> }
>
> -int ipv6_dev_get_saddr(struct net_device *dst_dev,
> +int ipv6_dev_get_saddr(struct net *net, struct net_device *dst_dev,
> const struct in6_addr *daddr, unsigned int prefs,
> struct in6_addr *saddr)
> {
> struct ipv6_saddr_score scores[2],
> *score = &scores[0], *hiscore = &scores[1];
> - struct net *net = dev_net(dst_dev);
> struct ipv6_saddr_dst dst;
> struct net_device *dev;
> int dst_type;
>
> + if (!net)
> + net = dev_net(dst_dev);
These lines are not needed, because the net parameter will be never
NULL, see below.
> dst_type = __ipv6_addr_type(daddr);
> dst.addr = daddr;
> dst.ifindex = dst_dev ? dst_dev->ifindex : 0;
> diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
> index 8d05527..f5de3f9 100644
> --- a/net/ipv6/fib6_rules.c
> +++ b/net/ipv6/fib6_rules.c
> @@ -93,7 +93,8 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
> if (flags & RT6_LOOKUP_F_SRCPREF_COA)
> srcprefs |= IPV6_PREFER_SRC_COA;
>
> - if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev,
> + if (ipv6_dev_get_saddr(net,
> + ip6_dst_idev(&rt->u.dst)->dev,
> &flp->fl6_dst, srcprefs,
> &saddr))
> goto again;
> diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
> index 52dddc2..29c7c99 100644
> --- a/net/ipv6/ip6_fib.c
> +++ b/net/ipv6/ip6_fib.c
> @@ -378,6 +378,7 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
>
> arg.skb = skb;
> arg.cb = cb;
> + arg.net = net;
> w->args = &arg;
>
> for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
> index a4402de..0e844c2 100644
> --- a/net/ipv6/ip6_output.c
> +++ b/net/ipv6/ip6_output.c
> @@ -934,7 +934,7 @@ static int ip6_dst_lookup_tail(struct sock *sk,
> goto out_err_release;
>
> if (ipv6_addr_any(&fl->fl6_src)) {
> - err = ipv6_dev_get_saddr(ip6_dst_idev(*dst)->dev,
> + err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev,
> &fl->fl6_dst,
> sk ? inet6_sk(sk)->srcprefs : 0,
> &fl->fl6_src);
> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
> index beb48e3..f1c62ba 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -549,7 +549,7 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
> override = 0;
> in6_ifa_put(ifp);
> } else {
> - if (ipv6_dev_get_saddr(dev, daddr,
> + if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
> inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
> &tmpaddr))
> return;
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 41b165f..9af6115 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -2106,7 +2106,8 @@ static inline size_t rt6_nlmsg_size(void)
> + nla_total_size(sizeof(struct rta_cacheinfo));
> }
>
> -static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
> +static int rt6_fill_node(struct net *net,
> + struct sk_buff *skb, struct rt6_info *rt,
> struct in6_addr *dst, struct in6_addr *src,
> int iif, int type, u32 pid, u32 seq,
> int prefix, int nowait, unsigned int flags)
> @@ -2189,7 +2190,7 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
> } else if (dst) {
> struct inet6_dev *idev = ip6_dst_idev(&rt->u.dst);
> struct in6_addr saddr_buf;
> - if (ipv6_dev_get_saddr(idev ? idev->dev : NULL,
> + if (ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
> dst, 0, &saddr_buf) == 0)
> NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
> }
> @@ -2234,7 +2235,8 @@ int rt6_dump_route(struct rt6_info *rt, void *p_arg)
> } else
> prefix = 0;
>
> - return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
> + return rt6_fill_node(arg->net,
> + arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
> NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
> prefix, 0, NLM_F_MULTI);
> }
> @@ -2300,7 +2302,7 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
> rt = (struct rt6_info*) ip6_route_output(net, NULL, &fl);
> skb->dst = &rt->u.dst;
>
> - err = rt6_fill_node(skb, rt, &fl.fl6_dst, &fl.fl6_src, iif,
> + err = rt6_fill_node(net, skb, rt, &fl.fl6_dst, &fl.fl6_src, iif,
> RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
> nlh->nlmsg_seq, 0, 0, 0);
> if (err < 0) {
> @@ -2327,7 +2329,7 @@ void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
> if (skb == NULL)
> goto errout;
>
> - err = rt6_fill_node(skb, rt, NULL, NULL, 0,
> + err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
> event, info->pid, seq, 0, 0, 0);
> if (err < 0) {
> /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
> diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
> index 8f1e054..5c36ef2 100644
> --- a/net/ipv6/xfrm6_policy.c
> +++ b/net/ipv6/xfrm6_policy.c
> @@ -57,7 +57,7 @@ static int xfrm6_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
> if (IS_ERR(dst))
> return -EHOSTUNREACH;
>
> - ipv6_dev_get_saddr(ip6_dst_idev(dst)->dev,
> + ipv6_dev_get_saddr(NULL, ip6_dst_idev(dst)->dev,
ipv6_dev_get_saddr(&init_net, ...
> (struct in6_addr *)&daddr->a6, 0,
> (struct in6_addr *)&saddr->a6);
> dst_release(dst);
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 483a01d..e0945d4 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -319,7 +319,8 @@ static void sctp_v6_get_saddr(struct sctp_sock *sk,
> __func__, asoc, dst, NIP6(daddr->v6.sin6_addr));
>
> if (!asoc) {
> - ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL,
> + ipv6_dev_get_saddr(NULL,
ipv6_dev_get_saddr(&init_net, ...
Using init_net instead of NULL makes sense for xfrm6 and sctp, because
they are not yet supported by the namespaces :) Furthermore it is more
practical to track the places where we have to take care of the namespaces.
Thanks.
-- Daniel
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