From deb4d858377e4a19d28697a553f8e39fa16fbbd8 Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Wed, 26 Mar 2014 19:35:41 +0900 Subject: [PATCH] ANDROID: net: ipv6: autoconf routes into per-device tables Currently, IPv6 router discovery always puts routes into RT6_TABLE_MAIN. This causes problems for connection managers that want to support multiple simultaneous network connections and want control over which one is used by default (e.g., wifi and wired). To work around this connection managers typically take the routes they prefer and copy them to static routes with low metrics in the main table. This puts the burden on the connection manager to watch netlink to see if the routes have changed, delete the routes when their lifetime expires, etc. Instead, this patch adds a per-interface sysctl to have the kernel put autoconf routes into different tables. This allows each interface to have its own autoconf table, and choosing the default interface (or using different interfaces at the same time for different types of traffic) can be done using appropriate ip rules. The sysctl behaves as follows: - = 0: default. Put routes into RT6_TABLE_MAIN as before. - > 0: manual. Put routes into the specified table. - < 0: automatic. Add the absolute value of the sysctl to the device's ifindex, and use that table. The automatic mode is most useful in conjunction with net.ipv6.conf.default.accept_ra_rt_table. A connection manager or distribution could set it to, say, -100 on boot, and thereafter just use IP rules. Change-Id: I82d16e3737d9cdfa6489e649e247894d0d60cbb1 Signed-off-by: Lorenzo Colitti [AmitP: Refactored original changes to align with the changes introduced by upstream commit 830218c1add1 ("net: ipv6: Fix processing of RAs in presence of VRF") Also folded following android-4.9 commit changes into this patch be65fb01da4d ("ANDROID: net: ipv6: remove unused variable ifindex in")] Signed-off-by: Amit Pundir --- include/linux/ipv6.h | 1 + include/net/addrconf.h | 2 ++ include/uapi/linux/ipv6.h | 1 + net/ipv6/addrconf.c | 39 ++++++++++++++++++++++++++++-- net/ipv6/route.c | 50 +++++++++------------------------------ 5 files changed, 52 insertions(+), 41 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index ea04ca024f0d..cfd0cc158326 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -42,6 +42,7 @@ struct ipv6_devconf { __s32 accept_ra_rt_info_max_plen; #endif #endif + __s32 accept_ra_rt_table; __s32 proxy_ndp; __s32 accept_source_route; __s32 accept_ra_from_local; diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 35f5aabd432f..bcd9b88bc4e8 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -261,6 +261,8 @@ static inline bool ipv6_is_mld(struct sk_buff *skb, int nexthdr, int offset) void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao); +u32 addrconf_rt_table(const struct net_device *dev, u32 default_table); + /* * anycast prototypes (anycast.c) */ diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index b22a9c4e1b12..8c3ea81d5bd7 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -166,6 +166,7 @@ enum { DEVCONF_ACCEPT_DAD, DEVCONF_FORCE_TLLAO, DEVCONF_NDISC_NOTIFY, + DEVCONF_ACCEPT_RA_RT_TABLE, DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL, DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL, DEVCONF_SUPPRESS_FRAG_NDISC, diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 8a1c846d3df9..135c8703047c 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -228,6 +228,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .accept_ra_rt_info_max_plen = 0, #endif #endif + .accept_ra_rt_table = 0, .proxy_ndp = 0, .accept_source_route = 0, /* we do not accept RH0 by default. */ .disable_ipv6 = 0, @@ -282,6 +283,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .accept_ra_rt_info_max_plen = 0, #endif #endif + .accept_ra_rt_table = 0, .proxy_ndp = 0, .accept_source_route = 0, /* we do not accept RH0 by default. */ .disable_ipv6 = 0, @@ -2273,6 +2275,31 @@ static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpad ipv6_regen_rndid(idev); } +u32 addrconf_rt_table(const struct net_device *dev, u32 default_table) { + /* Determines into what table to put autoconf PIO/RIO/default routes + * learned on this device. + * + * - If 0, use the same table for every device. This puts routes into + * one of RT_TABLE_{PREFIX,INFO,DFLT} depending on the type of route + * (but note that these three are currently all equal to + * RT6_TABLE_MAIN). + * - If > 0, use the specified table. + * - If < 0, put routes into table dev->ifindex + (-rt_table). + */ + struct inet6_dev *idev = in6_dev_get(dev); + u32 table; + int sysctl = idev->cnf.accept_ra_rt_table; + if (sysctl == 0) { + table = default_table; + } else if (sysctl > 0) { + table = (u32) sysctl; + } else { + table = (unsigned) dev->ifindex + (-sysctl); + } + in6_dev_put(idev); + return table; +} + /* * Add prefix route. */ @@ -2282,7 +2309,7 @@ addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev, unsigned long expires, u32 flags) { struct fib6_config cfg = { - .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX, + .fc_table = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_PREFIX), .fc_metric = IP6_RT_PRIO_ADDRCONF, .fc_ifindex = dev->ifindex, .fc_expires = expires, @@ -2315,7 +2342,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx, struct fib6_node *fn; struct rt6_info *rt = NULL; struct fib6_table *table; - u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX; + u32 tb_id = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_PREFIX); table = fib6_get_table(dev_net(dev), tb_id); if (!table) @@ -5021,6 +5048,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen; #endif #endif + array[DEVCONF_ACCEPT_RA_RT_TABLE] = cnf->accept_ra_rt_table; array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp; array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route; #ifdef CONFIG_IPV6_OPTIMISTIC_DAD @@ -6180,6 +6208,13 @@ static const struct ctl_table addrconf_sysctl[] = { }, #endif #endif + { + .procname = "accept_ra_rt_table", + .data = &ipv6_devconf.accept_ra_rt_table, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, { .procname = "proxy_ndp", .data = &ipv6_devconf.proxy_ndp, diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a96d5b385d8f..278271d6bd47 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2501,8 +2501,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net, const struct in6_addr *gwaddr, struct net_device *dev) { - u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; - int ifindex = dev->ifindex; + u32 tb_id = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_INFO); struct fib6_node *fn; struct rt6_info *rt = NULL; struct fib6_table *table; @@ -2517,7 +2516,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net, goto out; for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { - if (rt->dst.dev->ifindex != ifindex) + if (rt->dst.dev->ifindex != dev->ifindex) continue; if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) continue; @@ -2549,7 +2548,7 @@ static struct rt6_info *rt6_add_route_info(struct net *net, .fc_nlinfo.nl_net = net, }; - cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO, + cfg.fc_table = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_INFO), cfg.fc_dst = *prefix; cfg.fc_gateway = *gwaddr; @@ -2565,7 +2564,7 @@ static struct rt6_info *rt6_add_route_info(struct net *net, struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev) { - u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT; + u32 tb_id = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_MAIN); struct rt6_info *rt; struct fib6_table *table; @@ -2591,7 +2590,7 @@ struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr, unsigned int pref) { struct fib6_config cfg = { - .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, + .fc_table = l3mdev_fib_table(dev) ? : addrconf_rt_table(dev, RT6_TABLE_DFLT), .fc_metric = IP6_RT_PRIO_USER, .fc_ifindex = dev->ifindex, .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | @@ -2615,43 +2614,16 @@ struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr, return rt6_get_dflt_router(gwaddr, dev); } -static void __rt6_purge_dflt_routers(struct fib6_table *table) -{ - struct rt6_info *rt; - -restart: - read_lock_bh(&table->tb6_lock); - for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) { - if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) && - (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) { - dst_hold(&rt->dst); - read_unlock_bh(&table->tb6_lock); - ip6_del_rt(rt); - goto restart; - } - } - read_unlock_bh(&table->tb6_lock); - - table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER; +int rt6_addrconf_purge(struct rt6_info *rt, void *arg) { + if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) && + (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) + return -1; + return 0; } void rt6_purge_dflt_routers(struct net *net) { - struct fib6_table *table; - struct hlist_head *head; - unsigned int h; - - rcu_read_lock(); - - for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { - head = &net->ipv6.fib_table_hash[h]; - hlist_for_each_entry_rcu(table, head, tb6_hlist) { - if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER) - __rt6_purge_dflt_routers(table); - } - } - - rcu_read_unlock(); + fib6_clean_all(net, rt6_addrconf_purge, NULL); } static void rtmsg_to_fib6_config(struct net *net, -- 2.20.1