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2017-11-15ipv6: set all.accept_dad to 0 by defaultNicolas Dichtel1-1/+1
With commits 35e015e1f577 and a2d3f3e33853, the global 'accept_dad' flag is also taken into account (default value is 1). If either global or per-interface flag is non-zero, DAD will be enabled on a given interface. This is not backward compatible: before those patches, the user could disable DAD just by setting the per-interface flag to 0. Now, the user instead needs to set both flags to 0 to actually disable DAD. Restore the previous behaviour by setting the default for the global 'accept_dad' flag to 0. This way, DAD is still enabled by default, as per-interface flags are set to 1 on device creation, but setting them to 0 is enough to disable DAD on a given interface. - Before 35e015e1f57a7 and a2d3f3e33853: global per-interface DAD enabled [default] 1 1 yes X 0 no X 1 yes - After 35e015e1f577 and a2d3f3e33853: global per-interface DAD enabled [default] 1 1 yes 0 0 no 0 1 yes 1 0 yes - After this fix: global per-interface DAD enabled 1 1 yes 0 0 no [default] 0 1 yes 1 0 yes Fixes: 35e015e1f577 ("ipv6: fix net.ipv6.conf.all interface DAD handlers") Fixes: a2d3f3e33853 ("ipv6: fix net.ipv6.conf.all.accept_dad behaviour for real") CC: Stefano Brivio <sbrivio@redhat.com> CC: Matteo Croce <mcroce@redhat.com> CC: Erik Kline <ek@google.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11net: ipv6: sysctl to specify IPv6 ND traffic classMaciej Żenczykowski1-0/+11
Add a per-device sysctl to specify the default traffic class to use for kernel originated IPv6 Neighbour Discovery packets. Currently this includes: - Router Solicitation (ICMPv6 type 133) ndisc_send_rs() -> ndisc_send_skb() -> ip6_nd_hdr() - Neighbour Solicitation (ICMPv6 type 135) ndisc_send_ns() -> ndisc_send_skb() -> ip6_nd_hdr() - Neighbour Advertisement (ICMPv6 type 136) ndisc_send_na() -> ndisc_send_skb() -> ip6_nd_hdr() - Redirect (ICMPv6 type 137) ndisc_send_redirect() -> ndisc_send_skb() -> ip6_nd_hdr() and if the kernel ever gets around to generating RA's, it would presumably also include: - Router Advertisement (ICMPv6 type 134) (radvd daemon could pick up on the kernel setting and use it) Interface drivers may examine the Traffic Class value and translate the DiffServ Code Point into a link-layer appropriate traffic prioritization scheme. An example of mapping IETF DSCP values to IEEE 802.11 User Priority values can be found here: https://tools.ietf.org/html/draft-ietf-tsvwg-ieee-802-11 The expected primary use case is to properly prioritize ND over wifi. Testing: jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass 0 jzem22:~# echo -1 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass -bash: echo: write error: Invalid argument jzem22:~# echo 256 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass -bash: echo: write error: Invalid argument jzem22:~# echo 0 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass jzem22:~# echo 255 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass 255 jzem22:~# echo 34 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass 34 jzem22:~# echo $[0xDC] > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass jzem22:~# tcpdump -v -i eth0 icmp6 and src host jzem22.pgc and dst host fe80::1 tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes IP6 (class 0xdc, hlim 255, next-header ICMPv6 (58) payload length: 24) jzem22.pgc > fe80::1: [icmp6 sum ok] ICMP6, neighbor advertisement, length 24, tgt is jzem22.pgc, Flags [solicited] (based on original change written by Erik Kline, with minor changes) v2: fix 'suspicious rcu_dereference_check() usage' by explicitly grabbing the rcu_read_lock. Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Erik Kline <ek@google.com> Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-07ipv6: addrconf: fix a lockdep splatEric Dumazet1-5/+7
Fixes a case where GFP_ATOMIC allocation must be used instead of GFP_KERNEL one. [ 54.891146] lock_acquire+0xb3/0x2f0 [ 54.891153] ? fs_reclaim_acquire.part.60+0x5/0x30 [ 54.891165] fs_reclaim_acquire.part.60+0x29/0x30 [ 54.891170] ? fs_reclaim_acquire.part.60+0x5/0x30 [ 54.891178] kmem_cache_alloc_trace+0x3f/0x500 [ 54.891186] ? cyc2ns_read_end+0x1e/0x30 [ 54.891196] ipv6_add_addr+0x15a/0xc30 [ 54.891217] ? ipv6_create_tempaddr+0x2ea/0x5d0 [ 54.891223] ipv6_create_tempaddr+0x2ea/0x5d0 [ 54.891238] ? manage_tempaddrs+0x195/0x220 [ 54.891249] ? addrconf_prefix_rcv_add_addr+0x1c0/0x4f0 [ 54.891255] addrconf_prefix_rcv_add_addr+0x1c0/0x4f0 [ 54.891268] addrconf_prefix_rcv+0x2e5/0x9b0 [ 54.891279] ? neigh_update+0x446/0xb90 [ 54.891298] ? ndisc_router_discovery+0x5ab/0xf00 [ 54.891303] ndisc_router_discovery+0x5ab/0xf00 [ 54.891311] ? retint_kernel+0x2d/0x2d [ 54.891331] ndisc_rcv+0x1b6/0x270 [ 54.891340] icmpv6_rcv+0x6aa/0x9f0 [ 54.891345] ? ipv6_chk_mcast_addr+0x176/0x530 [ 54.891351] ? do_csum+0x17b/0x260 [ 54.891360] ip6_input_finish+0x194/0xb20 [ 54.891372] ip6_input+0x5b/0x2c0 [ 54.891380] ? ip6_rcv_finish+0x320/0x320 [ 54.891389] ip6_mc_input+0x15a/0x250 [ 54.891396] ipv6_rcv+0x772/0x1050 [ 54.891403] ? consume_skb+0xbe/0x2d0 [ 54.891412] ? ip6_make_skb+0x2a0/0x2a0 [ 54.891418] ? ip6_input+0x2c0/0x2c0 [ 54.891425] __netif_receive_skb_core+0xa0f/0x1600 [ 54.891436] ? process_backlog+0xac/0x400 [ 54.891441] process_backlog+0xfa/0x400 [ 54.891448] ? net_rx_action+0x145/0x1130 [ 54.891456] net_rx_action+0x310/0x1130 [ 54.891524] ? RTUSBBulkReceive+0x11d/0x190 [mt7610u_sta] [ 54.891538] __do_softirq+0x140/0xaba [ 54.891553] irq_exit+0x10b/0x160 [ 54.891561] do_IRQ+0xbb/0x1b0 Fixes: f3d9832e56c4 ("ipv6: addrconf: cleanup locking in ipv6_add_addr") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Acked-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05ipv6: remove IN6_ADDR_HSIZE from addrconf.hEric Dumazet1-0/+2
IN6_ADDR_HSIZE is private to addrconf.c, move it here to avoid confusion. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+1
Smooth Cong Wang's bug fix into 'net-next'. Basically put the bulk of the tcf_block_put() logic from 'net' into tcf_block_put_ext(), but after the offload unbind. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01ipv6: addrconf: increment ifp refcount before ipv6_del_addr()Eric Dumazet1-0/+1
In the (unlikely) event fixup_permanent_addr() returns a failure, addrconf_permanent_addr() calls ipv6_del_addr() without the mandatory call to in6_ifa_hold(), leading to a refcount error, spotted by syzkaller : WARNING: CPU: 1 PID: 3142 at lib/refcount.c:227 refcount_dec+0x4c/0x50 lib/refcount.c:227 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 3142 Comm: ip Not tainted 4.14.0-rc4-next-20171009+ #33 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x41c kernel/panic.c:181 __warn+0x1c4/0x1e0 kernel/panic.c:544 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178 do_trap_no_signal arch/x86/kernel/traps.c:212 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:261 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905 RIP: 0010:refcount_dec+0x4c/0x50 lib/refcount.c:227 RSP: 0018:ffff8801ca49e680 EFLAGS: 00010286 RAX: 000000000000002c RBX: ffff8801d07cfcdc RCX: 0000000000000000 RDX: 000000000000002c RSI: 1ffff10039493c90 RDI: ffffed0039493cc4 RBP: ffff8801ca49e688 R08: ffff8801ca49dd70 R09: 0000000000000000 R10: ffff8801ca49df58 R11: 0000000000000000 R12: 1ffff10039493cd9 R13: ffff8801ca49e6e8 R14: ffff8801ca49e7e8 R15: ffff8801d07cfcdc __in6_ifa_put include/net/addrconf.h:369 [inline] ipv6_del_addr+0x42b/0xb60 net/ipv6/addrconf.c:1208 addrconf_permanent_addr net/ipv6/addrconf.c:3327 [inline] addrconf_notify+0x1c66/0x2190 net/ipv6/addrconf.c:3393 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1697 call_netdevice_notifiers net/core/dev.c:1715 [inline] __dev_notify_flags+0x15d/0x430 net/core/dev.c:6843 dev_change_flags+0xf5/0x140 net/core/dev.c:6879 do_setlink+0xa1b/0x38e0 net/core/rtnetlink.c:2113 rtnl_newlink+0xf0d/0x1a40 net/core/rtnetlink.c:2661 rtnetlink_rcv_msg+0x733/0x1090 net/core/rtnetlink.c:4301 netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2408 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4313 netlink_unicast_kernel net/netlink/af_netlink.c:1273 [inline] netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1299 netlink_sendmsg+0xa4a/0xe70 net/netlink/af_netlink.c:1862 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x75b/0x8a0 net/socket.c:2049 __sys_sendmsg+0xe5/0x210 net/socket.c:2083 SYSC_sendmsg net/socket.c:2094 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2090 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7fa9174d3320 RSP: 002b:00007ffe302ae9e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffe302b2ae0 RCX: 00007fa9174d3320 RDX: 0000000000000000 RSI: 00007ffe302aea20 RDI: 0000000000000016 RBP: 0000000000000082 R08: 0000000000000000 R09: 000000000000000f R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe302b32a0 R13: 0000000000000000 R14: 00007ffe302b2ab8 R15: 00007ffe302b32b8 Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Ahern <dsahern@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01net: display hw address of source machine during ipv6 DAD failureVishwanath Pai1-3/+3
This patch updates the error messages displayed in kernel log to include hwaddress of the source machine that caused ipv6 duplicate address detection failures. Examples: a) When we receive a NA packet from another machine advertising our address: ICMPv6: NA: 34:ab:cd:56:11:e8 advertised our address 2001:db8:: on eth0! b) When we detect DAD failure during address assignment to an interface: IPv6: eth0: IPv6 duplicate address 2001:db8:: used by 34:ab:cd:56:11:e8 detected! v2: Changed %pI6 to %pI6c in ndisc_recv_na() Chaged the v6 address in the commit message to 2001:db8:: Suggested-by: Igor Lubashev <ilubashe@akamai.com> Signed-off-by: Vishwanath Pai <vpai@akamai.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: do not block BH in ipv6_chk_home_addr()Eric Dumazet1-3/+3
rcu_read_lock() is enough here, no need to block BH. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: do not block BH in /proc/net/if_inet6 handlingEric Dumazet1-8/+8
Table is really RCU protected, no need to block BH Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: do not block BH in ipv6_get_ifaddr()Eric Dumazet1-3/+3
rcu_read_lock() is enough here, no need to block BH. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: do not block BH in ipv6_chk_addr_and_flags()Eric Dumazet1-3/+3
rcu_read_lock() is enough here, as inet6_ifa_finish_destroy() uses kfree_rcu() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: add per netns perturbation in inet6_addr_hash()Eric Dumazet1-7/+9
Bring IPv6 in par with IPv4 : - Use net_hash_mix() to spread addresses a bit more. - Use 256 slots hash table instead of 16 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: factorize inet6_addr_hash() callEric Dumazet1-10/+5
ipv6_add_addr_hash() can compute the hash value outside of locked section and pass it to ipv6_chk_same_addr(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-24ipv6: addrconf: move ipv6_chk_same_addr() to avoid forward declarationEric Dumazet1-18/+17
ipv6_chk_same_addr() is only used by ipv6_add_addr_hash(), so moving it avoids a forward declaration. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20net: Add extack to validator_info structs used for address notifierDavid Ahern1-10/+12
Add extack to in_validator_info and in6_validator_info. Update the one user of each, ipvlan, to return an error message for failures. Only manual configuration of an address is plumbed in the IPv6 code path. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20net: ipv6: Make inet6addr_validator a blocking notifierDavid Ahern1-7/+14
inet6addr_validator chain was added by commit 3ad7d2468f79f ("Ipvlan should return an error when an address is already in use") to allow address validation before changes are committed and to be able to fail the address change with an error back to the user. The address validation is not done for addresses received from router advertisements. Handling RAs in softirq context is the only reason for the notifier chain to be atomic versus blocking. Since the only current user, ipvlan, of the validator chain ignores softirq context, the notifier can be made blocking and simply not invoked for softirq path. The blocking option is needed by spectrum for example to validate resources for an adding an address to an interface. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20ipv6: addrconf: cleanup locking in ipv6_add_addrDavid Ahern1-44/+60
ipv6_add_addr is called in process context with rtnl lock held (e.g., manual config of an address) or during softirq processing (e.g., autoconf and address from a router advertisement). Currently, ipv6_add_addr calls rcu_read_lock_bh shortly after entry and does not call unlock until exit, minus the call around the address validator notifier. Similarly, addrconf_hash_lock is taken after the validator notifier and held until exit. This forces the allocation of inet6_ifaddr to always be atomic. Refactor ipv6_add_addr as follows: 1. add an input boolean to discriminate the call path (process context or softirq). This new flag controls whether the alloc can be done with GFP_KERNEL or GFP_ATOMIC. 2. Move the rcu_read_lock_bh and unlock calls only around functions that do rcu updates. 3. Remove the in6_dev_hold and put added by 3ad7d2468f79f ("Ipvlan should return an error when an address is already in use."). This was done presumably because rcu_read_unlock_bh needs to be called before calling the validator. Since rcu_read_lock is not needed before the validator runs revert the hold and put added by 3ad7d2468f79f and only do the hold when setting ifp->idev. 4. move duplicate address check and insertion of new address in the global address hash into a helper. The helper is called after an ifa is allocated and filled in. This allows the ifa for manually configured addresses to be done with GFP_KERNEL and reduces the overall amount of time with rcu_read_lock held and hash table spinlock held. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-11ipv6: addrconf: don't use rtnl mutex in RTM_GETADDRFlorian Westphal1-7/+7
Similar to the previous patch, use the device lookup functions that bump device refcount and flag this as DOIT_UNLOCKED to avoid rtnl mutex. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-11ipv6: addrconf: don't use rtnl mutex in RTM_GETNETCONFFlorian Westphal1-10/+14
Instead of relying on rtnl mutex bump device reference count. After this change, values reported can change in parallel, but thats not much different from current state, as anyone can change the settings right after rtnl_unlock (and before userspace processed reply). While at it, switch to GFP_KERNEL allocation. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+2
2017-10-08ipv6: avoid cache line dirtying in ipv6_dev_get_saddr()Eric Dumazet1-11/+6
By extending the rcu section a bit, we can avoid these very expensive in6_ifa_put()/in6_ifa_hold() calls done in __ipv6_dev_get_saddr() and ipv6_dev_get_saddr() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-08ipv6: __ipv6_dev_get_saddr() rcu conversionEric Dumazet1-3/+1
Callers hold rcu_read_lock(), so we do not need the rcu_read_lock()/rcu_read_unlock() pair. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-08ipv6: ipv6_chk_prefix() rcu conversionEric Dumazet1-5/+3
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-08ipv6: ipv6_chk_custom_prefix() rcu conversionEric Dumazet1-5/+3
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-08ipv6: ipv6_count_addresses() rcu conversionEric Dumazet1-6/+6
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-08ipv6: prepare RCU lookups for idev->addr_listEric Dumazet1-15/+6
inet6_ifa_finish_destroy() already uses kfree_rcu() to free inet6_ifaddr structs. We need to use proper list additions/deletions in order to allow readers to use RCU instead of idev->lock rwlock. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: fix net.ipv6.conf.all.accept_dad behaviour for realMatteo Croce1-2/+2
Commit 35e015e1f577 ("ipv6: fix net.ipv6.conf.all interface DAD handlers") was intended to affect accept_dad flag handling in such a way that DAD operation and mode on a given interface would be selected according to the maximum value of conf/{all,interface}/accept_dad. However, addrconf_dad_begin() checks for particular cases in which we need to skip DAD, and this check was modified in the wrong way. Namely, it was modified so that, if the accept_dad flag is 0 for the given interface *or* for all interfaces, DAD would be skipped. We have instead to skip DAD if accept_dad is 0 for the given interface *and* for all interfaces. Fixes: 35e015e1f577 ("ipv6: fix net.ipv6.conf.all interface DAD handlers") Acked-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Matteo Croce <mcroce@redhat.com> Reported-by: Erik Kline <ek@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: replace rwlock with rcu and spinlock in fib6_tableWei Wang1-6/+5
With all the preparation work before, we are now ready to replace rwlock with rcu and spinlock in fib6_table. That means now all fib6_node in fib6_table are protected by rcu. And when freeing fib6_node, call_rcu() is used to wait for the rcu grace period before releasing the memory. When accessing fib6_node, corresponding rcu APIs need to be used. And all previous sessions protected by the write lock will now be protected by the spin lock per table. All previous sessions protected by read lock will now be protected by rcu_read_lock(). A couple of things to note here: 1. As part of the work of replacing rwlock with rcu, the linked list of fn->leaf now has to be rcu protected as well. So both fn->leaf and rt->dst.rt6_next are now __rcu tagged and corresponding rcu APIs are used when manipulating them. 2. For fn->rr_ptr, first of all, it also needs to be rcu protected now and is tagged with __rcu and rcu APIs are used in corresponding places. Secondly, fn->rr_ptr is changed in rt6_select() which is a reader thread. This makes the issue a bit complicated. We think a valid solution for it is to let rt6_select() grab the tb6_lock if it decides to change it. As it is not in the normal operation and only happens when there is no valid neighbor cache for the route, we think the performance impact should be low. 3. fib6_walk_continue() has to be called with tb6_lock held even in the route dumping related functions, e.g. inet6_dump_fib(), fib6_tables_dump() and ipv6_route_seq_ops. It is because fib6_walk_continue() makes modifications to the walker structure, and so are fib6_repair_tree() and fib6_del_route(). In order to do proper syncing between them, we need to let fib6_walk_continue() hold the lock. We may be able to do further improvement on the way we do the tree walk to get rid of the need for holding the spin lock. But not for now. 4. When fib6_del_route() removes a route from the tree, we no longer mark rt->dst.rt6_next to NULL to make simultaneous reader be able to further traverse the list with rcu. However, rt->dst.rt6_next is only valid within this same rcu period. No one should access it later. 5. All the operation of atomic_inc(rt->rt6i_ref) is changed to be performed before we publish this route (either by linking it to fn->leaf or insert it in the list pointed by fn->leaf) just to be safe because as soon as we publish the route, some read thread will be able to access it. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: replace dst_hold() with dst_hold_safe() in routing codeWei Wang1-1/+2
With rwlock, it is safe to call dst_hold() in the read thread because read thread is guaranteed to be separated from write thread. However, after we replace rwlock with rcu, it is no longer safe to use dst_hold(). A dst might already have been deleted but is waiting for the rcu grace period to pass before freeing the memory when a read thread is trying to do dst_hold(). This could potentially cause double free issue. So this commit replaces all dst_hold() with dst_hold_safe() in all read thread to avoid this double free issue. And in order to make the code more compact, a new function ip6_hold_safe() is introduced. It calls dst_hold_safe() first, and if that fails, it will either fall back to hold and return net->ipv6.ip6_null_entry or set rt to NULL according to the caller's need. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: hook up exception table to store dst cacheWei Wang1-1/+0
This commit makes use of the exception hash table implementation to store dst caches created by pmtu discovery and ip redirect into the hash table under the rt_info and no longer inserts these routes into fib6 tree. This makes the fib6 tree only contain static configured routes and could now be protected by rcu instead of a rw lock. With this change, in the route lookup related functions, after finding the rt6_info with the longest prefix, we also need to search for the exception table before doing backtracking. In the route delete function, if the route being deleted is not a dst cache, deletion of this route also need to flush the whole hash table under it. If it is a dst cache, then only delete the cached dst in the hash table. Note: for fib6_walk_continue() function, w->root now is always pointing to a root node considering that fib6_prune_clones() is removed from the code. So we add a WARN_ON() msg to make sure w->root always points to a root node and also removed the update of w->root in fib6_repair_tree(). This is a prerequisite for later patch because we don't need to make w->root as rcu protected when replacing rwlock with RCU. Also, we remove all prune related variables as it is no longer used. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: prepare fib6_locate() for exception tableWei Wang1-1/+1
fib6_locate() is used to find the fib6_node according to the passed in prefix address key. It currently tries to find the fib6_node with the exact match of the passed in key. However, when we move cached routes into the exception table, fib6_locate() will fail to find the fib6_node for it as the cached routes will be stored in the exception table under the fib6_node with the longest prefix match of the cache's dst addr key. This commit adds a new parameter to let the caller specify if it needs exact match or longest prefix match. Right now, all callers still does exact match when calling fib6_locate(). It will be changed in later commit where exception table is hooked up to store cached routes. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04rtnetlink: remove __rtnl_af_unregisterFlorian Westphal1-2/+2
switch the only caller to rtnl_af_unregister. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-30net: ipv6: send NS for DAD when link operationally upMike Manning1-6/+6
The NS for DAD are sent on admin up as long as a valid qdisc is found. A race condition exists by which these packets will not egress the interface if the operational state of the lower device is not yet up. The solution is to delay DAD until the link is operationally up according to RFC2863. Rather than only doing this, follow the existing code checks by deferring IPv6 device initialization altogether. The fix allows DAD on devices like tunnels that are controlled by userspace control plane. The fix has no impact on regular deployments, but means that there is no IPv6 connectivity until the port has been opened in the case of port-based network access control, which should be desirable. Signed-off-by: Mike Manning <mmanning@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-26ipv6: Remove redundant unlikely()Tobias Klauser1-1/+1
IS_ERR() already implies unlikely(), so it can be omitted. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19ipv6: fix net.ipv6.conf.all interface DAD handlersMatteo Croce1-7/+20
Currently, writing into net.ipv6.conf.all.{accept_dad,use_optimistic,optimistic_dad} has no effect. Fix handling of these flags by: - using the maximum of global and per-interface values for the accept_dad flag. That is, if at least one of the two values is non-zero, enable DAD on the interface. If at least one value is set to 2, enable DAD and disable IPv6 operation on the interface if MAC-based link-local address was found - using the logical OR of global and per-interface values for the optimistic_dad flag. If at least one of them is set to one, optimistic duplicate address detection (RFC 4429) is enabled on the interface - using the logical OR of global and per-interface values for the use_optimistic flag. If at least one of them is set to one, optimistic addresses won't be marked as deprecated during source address selection on the interface. While at it, as we're modifying the prototype for ipv6_use_optimistic_addr(), drop inline, and let the compiler decide. Fixes: 7fd2561e4ebd ("net: ipv6: Add a sysctl to make optimistic addresses useful candidates") Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-19net: ipv6: fix regression of no RTM_DELADDR sent after DAD failureMike Manning1-2/+3
Commit f784ad3d79e5 ("ipv6: do not send RTM_DELADDR for tentative addresses") incorrectly assumes that no RTM_NEWADDR are sent for addresses in tentative state, as this does happen for the standard IPv6 use-case of DAD failure, see the call to ipv6_ifa_notify() in addconf_dad_stop(). So as a result of this change, no RTM_DELADDR is sent after DAD failure for a link-local when strict DAD (accept_dad=2) is configured, or on the next admin down in other cases. The absence of this notification breaks backwards compatibility and causes problems after DAD failure if this notification was being relied on. The solution is to allow RTM_DELADDR to still be sent after DAD failure. Fixes: f784ad3d79e5 ("ipv6: do not send RTM_DELADDR for tentative addresses") Signed-off-by: Mike Manning <mmanning@brocade.com> Cc: Mahesh Bandewar <maheshb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+1
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28ipv6: fix sparse warning on rt6i_nodeWei Wang1-1/+1
Commit c5cff8561d2d adds rcu grace period before freeing fib6_node. This generates a new sparse warning on rt->rt6i_node related code: net/ipv6/route.c:1394:30: error: incompatible types in comparison expression (different address spaces) ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison expression (different address spaces) This commit adds "__rcu" tag for rt6i_node and makes sure corresponding rcu API is used for it. After this fix, sparse no longer generates the above warning. Fixes: c5cff8561d2d ("ipv6: add rcu grace period before freeing fib6_node") Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21net: ipv6: put host and anycast routes on device with addressDavid Ahern1-42/+0
One nagging difference between ipv4 and ipv6 is host routes for ipv6 addresses are installed using the loopback device or VRF / L3 Master device. e.g., 2001:db8:1::/120 dev veth0 proto kernel metric 256 pref medium local 2001:db8:1::1 dev lo table local proto kernel metric 0 pref medium Using the loopback device is convenient -- necessary for local tx, but has some nasty side effects, most notably setting the 'lo' device down causes all host routes for all local IPv6 address to be removed from the FIB and completely breaks IPv6 networking across all interfaces. This patch puts FIB entries for IPv6 routes against the device. This simplifies the routes in the FIB, for example by making dst->dev and rt6i_idev->dev the same (a future patch can look at removing the device reference taken for rt6i_idev for FIB entries). When copies are made on FIB lookups, the cloned route has dst->dev set to loopback (or the L3 master device). This is needed for the local Tx of packets to local addresses. With fib entries allocated against the real network device, the addrconf code that reinserts host routes on admin up of 'lo' is no longer needed. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09rtnetlink: make rtnl_register accept a flags parameterFlorian Westphal1-7/+7
This change allows us to later indicate to rtnetlink core that certain doit functions should be called without acquiring rtnl_mutex. This change should have no effect, we simply replace the last (now unused) calcit argument with the new flag. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03ipv6: Regenerate host route according to node pointer upon interface upIdo Schimmel1-2/+2
When an interface is brought back up, the kernel tries to restore the host routes tied to its permanent addresses. However, if the host route was removed from the FIB, then we need to reinsert it. This is done by releasing the current dst and allocating a new, so as to not reuse a dst with obsolete values. Since this function is called under RTNL and using the same explanation from the previous patch, we can test if the route is in the FIB by checking its node pointer instead of its reference count. Tested using the following script and Andrey's reproducer mentioned in commit 8048ced9beb2 ("net: ipv6: regenerate host route if moved to gc list") and linked below: $ ip link set dev lo up $ ip link add dummy1 type dummy $ ip -6 address add cafe::1/64 dev dummy1 $ ip link set dev lo down # cafe::1/128 is removed $ ip link set dev dummy1 up $ ip link set dev lo up The host route is correctly regenerated. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Link: http://lkml.kernel.org/r/CAAeHK+zSe82vc5gCRgr_EoUwiALPnWVdWJBPwJZBpbxYz=kGJw@mail.gmail.com Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03ipv6: Regenerate host route according to node pointer upon loopback upIdo Schimmel1-1/+1
When the loopback device is brought back up we need to check if the host route attached to the address is still in the FIB and regenerate one in case it's not. Host routes using the loopback device are always inserted into and removed from the FIB under RTNL (under which this function is called), so we can test their node pointer instead of the reference count in order to check if the route is in the FIB or not. Tested using the following script from Nicolas mentioned in commit a220445f9f43 ("ipv6: correctly add local routes when lo goes up"): $ ip link add dummy1 type dummy $ ip link set dummy1 up $ ip link set lo down ; ip link set lo up The host route is correctly regenerated. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04net, ipv6: convert inet6_ifaddr.refcnt from atomic_t to refcount_tReshetova, Elena1-1/+1
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04net, ipv6: convert inet6_dev.refcnt from atomic_t to refcount_tReshetova, Elena1-1/+1
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-03ipv6: dad: don't remove dynamic addresses if link is downSabrina Dubroca1-9/+9
Currently, when the link for $DEV is down, this command succeeds but the address is removed immediately by DAD (1): ip addr add 1111::12/64 dev $DEV valid_lft 3600 preferred_lft 1800 In the same situation, this will succeed and not remove the address (2): ip addr add 1111::12/64 dev $DEV ip addr change 1111::12/64 dev $DEV valid_lft 3600 preferred_lft 1800 The comment in addrconf_dad_begin() when !IF_READY makes it look like this is the intended behavior, but doesn't explain why: * If the device is not ready: * - keep it tentative if it is a permanent address. * - otherwise, kill it. We clearly cannot prevent userspace from doing (2), but we can make (1) work consistently with (2). addrconf_dad_stop() is only called in two cases: if DAD failed, or to skip DAD when the link is down. In that second case, the fix is to avoid deleting the address, like we already do for permanent addresses. Fixes: 3c21edbd1137 ("[IPV6]: Defer IPv6 device initialization until the link becomes ready.") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+3
A set of overlapping changes in macvlan and the rocker driver, nothing serious. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22ipv6: avoid unregistering inet6_dev for loopbackWANG Cong1-2/+3
The per netns loopback_dev->ip6_ptr is unregistered and set to NULL when its mtu is set to smaller than IPV6_MIN_MTU, this leads to that we could set rt->rt6i_idev NULL after a rt6_uncached_list_flush_dev() and then crash after another call. In this case we should just bring its inet6_dev down, rather than unregistering it, at least prior to commit 176c39af29bc ("netns: fix addrconf_ifdown kernel panic") we always override the case for loopback. Thanks a lot to Andrey for finding a reliable reproducer. Fixes: 176c39af29bc ("netns: fix addrconf_ifdown kernel panic") Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Daniel Lezcano <dlezcano@fr.ibm.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-3/+3
Two entries being added at the same time to the IFLA policy table, whilst parallel bug fixes to decnet routing dst handling overlapping with the dst gc removal in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17ipv6: call dst_hold_safe() properlyWei Wang1-2/+2
Similar as ipv4, ipv6 path also needs to call dst_hold_safe() when necessary to avoid double free issue on the dst. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15ipv6: fix calling in6_ifa_hold incorrectly for dad workXin Long1-3/+3
Now when starting the dad work in addrconf_mod_dad_work, if the dad work is idle and queued, it needs to hold ifa. The problem is there's one gap in [1], during which if the pending dad work is removed elsewhere. It will miss to hold ifa, but the dad word is still idea and queue. if (!delayed_work_pending(&ifp->dad_work)) in6_ifa_hold(ifp); <--------------[1] mod_delayed_work(addrconf_wq, &ifp->dad_work, delay); An use-after-free issue can be caused by this. Chen Wei found this issue when WARN_ON(!hlist_unhashed(&ifp->addr_lst)) in net6_ifa_finish_destroy was hit because of it. As Hannes' suggestion, this patch is to fix it by holding ifa first in addrconf_mod_dad_work, then calling mod_delayed_work and putting ifa if the dad_work is already in queue. Note that this patch did not choose to fix it with: if (!mod_delayed_work(delay)) in6_ifa_hold(ifp); As with it, when delay == 0, dad_work would be scheduled immediately, all addrconf_mod_dad_work(0) callings had to be moved under ifp->lock. Reported-by: Wei Chen <weichen@redhat.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>