kernel/include/net/ip6_fib.h, branch linux-3.4.y

ipv6: fix handling of blackhole and prohibit routes

2016-10-26T15:15:43Z

commit ef2c7d7b59708d54213c7556a82d14de9a7e4475 upstream. When adding a blackhole or a prohibit route, they were handling like classic routes. Moreover, it was only possible to add this kind of routes by specifying an interface. Bug already reported here: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=498498 Before the patch: $ ip route add blackhole 2001::1/128 RTNETLINK answers: No such device $ ip route add blackhole 2001::1/128 dev eth0 $ ip -6 route | grep 2001 2001::1 dev eth0 metric 1024 After: $ ip route add blackhole 2001::1/128 $ ip -6 route | grep 2001 blackhole 2001::1 dev lo metric 1024 error -22 v2: wrong patch v3: add a field fc_type in struct fib6_config to store RTN_* type Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller Signed-off-by: Zefan Li

ipv6: prevent fib6_run_gc() contention

2016-03-21T01:17:57Z

commit 2ac3ac8f86f2fe065d746d9a9abaca867adec577 upstream. On a high-traffic router with many processors and many IPv6 dst entries, soft lockup in fib6_run_gc() can occur when number of entries reaches gc_thresh. This happens because fib6_run_gc() uses fib6_gc_lock to allow only one thread to run the garbage collector but ip6_dst_gc() doesn't update net->ipv6.ip6_rt_last_gc until fib6_run_gc() returns. On a system with many entries, this can take some time so that in the meantime, other threads pass the tests in ip6_dst_gc() (ip6_rt_last_gc is still not updated) and wait for the lock. They then have to run the garbage collector one after another which blocks them for quite long. Resolve this by replacing special value ~0UL of expire parameter to fib6_run_gc() by explicit "force" parameter to choose between spin_lock_bh() and spin_trylock_bh() and call fib6_run_gc() with force=false if gc_thresh is reached but not max_size. Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li

ipv6: clean up rt6_clean_expires

2012-04-18T02:31:59Z

Functionally, this change is a NOP. Semantically, rt6_clean_expires() wants to do rt->dst.from = NULL instead of rt->dst.expires = 0. It is clearing the RTF_EXPIRES flag, so the union is going to be treated as a pointer (dst.from) not a long (dst.expires). Signed-off-by: Jiri Bohac Signed-off-by: David S. Miller

ipv6: fix rt6_update_expires

2012-04-18T02:31:51Z

Commit 1716a961 (ipv6: fix problem with expired dst cache) broke PMTU discovery. rt6_update_expires() calls dst_set_expires(), which only updates dst->expires if it has not been set previously (expires == 0) or if the new expires is earlier than the current dst->expires. rt6_update_expires() needs to zero rt->dst.expires, otherwise it will contain ivalid data left over from rt->dst.from and will confuse dst_set_expires(). Signed-off-by: Jiri Bohac Signed-off-by: David S. Miller

ipv6: fix problem with expired dst cache

2012-04-13T16:58:29Z

If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. this dst cache will not check expire because it has no RTF_EXPIRES flag. So this dst cache will always be used until the dst gc run. Change the struct dst_entry,add a union contains new pointer from and expires. When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. we can use this field to point to where the dst cache copy from. The dst.from is only used in IPV6. rt6_check_expired check if rt6_info.dst.from is expired. ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. ip6_dst_destroy release the ort. Add some functions to operate the RTF_EXPIRES flag and expires(from) together. and change the code to use these new adding functions. Changes from v5: modify ip6_route_add and ndisc_router_discovery to use new adding functions. Only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. Signed-off-by: Gao feng Signed-off-by: David S. Miller

IPv6: Avoid taking write lock for /proc/net/ipv6_route

2011-12-30T22:07:33Z

During some debugging I needed to look into how /proc/net/ipv6_route operated and in my digging I found its calling fib6_clean_all() which uses "write_lock_bh(&table->tb6_lock)" before doing the walk of the table. I found this on 2.6.32, but reading the code I believe the same basic idea exists currently. Looking at the rtnetlink code they are only calling "read_lock_bh(&table->tb6_lock);" via fib6_dump_table(). While I realize reading from proc isn't the recommended way of fetching the ipv6 route table; taking a write lock seems unnecessary and would probably cause network performance issues. To verify this I loaded up the ipv6 route table and then ran iperf in 3 cases: * doing nothing * reading ipv6 route table via proc (while :; do cat /proc/net/ipv6_route > /dev/null; done) * reading ipv6 route table via rtnetlink (while :; do ip -6 route show table all > /dev/null; done) * Load the ipv6 route table up with: * for ((i = 0;i < 4000;i++)); do ip route add unreachable 2000::$i; done * iperf commands: * client: iperf -i 1 -V -c * server: iperf -V -s * iperf results - 3 runs each (in Mbits/sec) * nothing: client: 927,927,927 server: 927,927,927 * proc: client: 179,97,96,113 server: 142,112,133 * iproute: client: 928,927,928 server: 927,927,927 lock_stat shows taking the write lock is causing the slowdown. Using this info I decided to write a version of fib6_clean_all() which replaces write_lock_bh(&table->tb6_lock) with read_lock_bh(&table->tb6_lock). With this new function I see the same results as with my rtnetlink iperf test. Signed-off-by: Josh Hunt Signed-off-by: David S. Miller

ipv6: Kill rt6i_dev and rt6i_expires defines.

2011-12-29T01:19:20Z

It just obscures that the netdevice pointer and the expires value are implemented in the dst_entry sub-object of the ipv6 route. And it makes grepping for dst_entry member uses much harder too. Signed-off-by: David S. Miller

ipv6: Get rid of rt6i_nexthop macro.

2011-07-18T06:11:35Z

It just makes it harder to see 1) what the code is doing and 2) grep for all users of dst{->,.}neighbour Signed-off-by: David S. Miller

net: Remove KERNEL cpp checks from include/net

2011-04-24T17:54:56Z

These header files are never installed to user consumption, so any __KERNEL__ cpp checks are superfluous. Projects should also not copy these files into their userland utility sources and try to use them there. If they insist on doing so, the onus is on them to sanitize the headers as needed. Signed-off-by: David S. Miller

inet: constify ip headers and in6_addr

2011-04-22T18:04:14Z

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers where possible, to make code intention more obvious. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller