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2022-07-11netfilter: nf_flow_table: count pending offload workqueue tasksVlad Buslov1-0/+6
To improve hardware offload debuggability count pending 'add', 'del' and 'stats' flow_table offload workqueue tasks. Counters are incremented before scheduling new task and decremented when workqueue handler finishes executing. These counters allow user to diagnose congestion on hardware offload workqueues that can happen when either CPU is starved and workqueue jobs are executed at lower rate than new ones are added or when hardware/driver can't keep up with the rate. Implement the described counters as percpu counters inside new struct netns_ft which is stored inside struct net. Expose them via new procfs file '/proc/net/stats/nf_flowtable' that is similar to existing 'nf_conntrack' file. Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: Oz Shlomo <ozsh@nvidia.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-06-22af_unix: Define a per-netns hash table.Kuniyuki Iwashima1-0/+2
This commit adds a per netns hash table for AF_UNIX, which size is fixed as UNIX_HASH_SIZE for now. The first implementation defines a per-netns hash table as a single array of lock and list: struct unix_hashbucket { spinlock_t lock; struct hlist_head head; }; struct netns_unix { struct unix_hashbucket *hash; ... }; But, Eric pointed out memory cost that the structure has holes because of sizeof(spinlock_t), which is 4 (or more if LOCKDEP is enabled). [0] It could be expensive on a host with thousands of netns and few AF_UNIX sockets. For this reason, a per-netns hash table uses two dense arrays. struct unix_table { spinlock_t *locks; struct hlist_head *buckets; }; struct netns_unix { struct unix_table table; ... }; Note the length of the list has a significant impact rather than lock contention, so having shared locks can be an option. But, per-netns locks and lists still perform better than the global locks and per-netns lists. [1] Also, this patch adds a change so that struct netns_unix disappears from struct net if CONFIG_UNIX is disabled. [0]: https://lore.kernel.org/netdev/CANn89iLVxO5aqx16azNU7p7Z-nz5NrnM5QTqOzueVxEnkVTxyg@mail.gmail.com/ [1]: https://lore.kernel.org/netdev/20220617175215.1769-1-kuniyu@amazon.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-10net: make net->dev_unreg_count atomicEric Dumazet1-1/+1
Having to acquire rtnl from netdev_run_todo() for every dismantled device is not desirable when/if rtnl is under stress. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-06net: initialize init_net earlierEric Dumazet1-0/+6
While testing a patch that will follow later ("net: add netns refcount tracker to struct nsproxy") I found that devtmpfs_init() was called before init_net was initialized. This is a bug, because devtmpfs_setup() calls ksys_unshare(CLONE_NEWNS); This has the effect of increasing init_net refcount, which will be later overwritten to 1, as part of setup_net(&init_net) We had too many prior patches [1] trying to work around the root cause. Really, make sure init_net is in BSS section, and that net_ns_init() is called earlier at boot time. Note that another patch ("vfs: add netns refcount tracker to struct fs_context") also will need net_ns_init() being called before vfs_caches_init() As a bonus, this patch saves around 4KB in .data section. [1] f8c46cb39079 ("netns: do not call pernet ops for not yet set up init_net namespace") b5082df8019a ("net: Initialise init_net.count to 1") 734b65417b24 ("net: Statically initialize init_net.dev_base_head") v2: fixed a build error reported by kernel build bots (CONFIG_NET=n) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-10net: add networking namespace refcount trackerEric Dumazet1-0/+34
We have 100+ syzbot reports about netns being dismantled too soon, still unresolved as of today. We think a missing get_net() or an extra put_net() is the root cause. In order to find the bug(s), and be able to spot future ones, this patch adds CONFIG_NET_NS_REFCNT_TRACKER and new helpers to precisely pair all put_net() with corresponding get_net(). To use these helpers, each data structure owning a refcount should also use a "netns_tracker" to pair the get and put. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-01netfilter: remove xt pernet dataFlorian Westphal1-2/+0
clusterip is now handled via net_generic. NOTRACK is tiny compared to rest of xt_CT feature set, even the existing deprecation warning is bigger than the actual functionality. Just remove the warning, its not worth keeping/adding a net_generic one. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-07-29mctp: Add initial routing frameworkJeremy Kerr1-0/+4
Add a simple routing table, and a couple of route output handlers, and the mctp packet_type & handler. Includes changes from Matt Johnston <matt@codeconstruct.com.au>. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+13
Trivial conflicts in net/can/isotp.c and tools/testing/selftests/net/mptcp/mptcp_connect.sh scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c to include/linux/ptp_clock_kernel.h in -next so re-apply the fix there. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-16net/smc: Make SMC statistics network namespace awareGuvenc Gulce1-0/+4
Make the gathered SMC statistics network namespace aware, for each namespace collect an own set of statistic information. Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-15net: inline function get_net_ns_by_fd if NET_NS is disabledChangbin Du1-1/+6
The function get_net_ns_by_fd() could be inlined when NET_NS is not enabled. Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12net: make get_net_ns return error if NET_NS is disabledChangbin Du1-0/+7
There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled. The reason is that nsfs tries to access ns->ops but the proc_ns_operations is not implemented in this case. [7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010 [7.670268] pgd = 32b54000 [7.670544] [00000010] *pgd=00000000 [7.671861] Internal error: Oops: 5 [#1] SMP ARM [7.672315] Modules linked in: [7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16 [7.673309] Hardware name: Generic DT based system [7.673642] PC is at nsfs_evict+0x24/0x30 [7.674486] LR is at clear_inode+0x20/0x9c The same to tun SIOCGSKNS command. To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is disabled. Meanwhile move it to right place net/core/net_namespace.c. Signed-off-by: Changbin Du <changbin.du@gmail.com> Fixes: c62cce2caee5 ("net: add an ioctl to get a socket network namespace") Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Christian Brauner <christian.brauner@ubuntu.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-09net: dccp: use net_generic storageFlorian Westphal1-4/+0
DCCP is virtually never used, so no need to use space in struct net for it. Put the pernet ipv4/v6 socket in the dccp ipv4/ipv6 modules instead. Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20210408174502.1625-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-9/+0
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following batch contains Netfilter/IPVS updates for your net-next tree: 1) Simplify log infrastructure modularity: Merge ipv4, ipv6, bridge, netdev and ARP families to nf_log_syslog.c. Add module softdeps. This fixes a rare deadlock condition that might occur when log module autoload is required. From Florian Westphal. 2) Moves part of netfilter related pernet data from struct net to net_generic() infrastructure. All of these users can be modules, so if they are not loaded there is no need to waste space. Size reduction is 7 cachelines on x86_64, also from Florian. 2) Update nftables audit support to report events once per table, to get it aligned with iptables. From Richard Guy Briggs. 3) Check for stale routes from the flowtable garbage collector path. This is fixing IPv6 which breaks due missing check for the dst_cookie. 4) Add a nfnl_fill_hdr() function to simplify netlink + nfnetlink headers setup. 5) Remove documentation on several statified functions. 6) Remove printk on netns creation for the FTP IPVS tracker, from Florian Westphal. 7) Remove unnecessary nf_tables_destroy_list_lock spinlock initialization, from Yang Yingliang. 7) Remove a duplicated forward declaration in ipset, from Wan Jiabing. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-06net: remove obsolete members from struct netFlorian Westphal1-9/+0
all have been moved to generic_net infra. On x86_64, this reduces struct net size from 70 to 63 cache lines (4480 to 4032 byte). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-01include: net: Remove repeated struct declarationWan Jiabing1-1/+0
struct ctl_table_header is declared twice. One is declared at 46th line. The blew one is not needed. Remove the duplicate. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11net: initialize net->net_cookie at netns setupEric Dumazet1-3/+1
It is simpler to make net->net_cookie a plain u64 written once in setup_net() instead of looping and using atomic64 helpers. Lorenz Bauer wants to add SO_NETNS_COOKIE socket option and this patch would makes his patch series simpler. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Lorenz Bauer <lmb@cloudflare.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-15Merge tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-3/+0
Pull networking updates from Jakub Kicinski: "Core: - support "prefer busy polling" NAPI operation mode, where we defer softirq for some time expecting applications to periodically busy poll - AF_XDP: improve efficiency by more batching and hindering the adjacency cache prefetcher - af_packet: make packet_fanout.arr size configurable up to 64K - tcp: optimize TCP zero copy receive in presence of partial or unaligned reads making zero copy a performance win for much smaller messages - XDP: add bulk APIs for returning / freeing frames - sched: support fragmenting IP packets as they come out of conntrack - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs BPF: - BPF switch from crude rlimit-based to memcg-based memory accounting - BPF type format information for kernel modules and related tracing enhancements - BPF implement task local storage for BPF LSM - allow the FENTRY/FEXIT/RAW_TP tracing programs to use bpf_sk_storage Protocols: - mptcp: improve multiple xmit streams support, memory accounting and many smaller improvements - TLS: support CHACHA20-POLY1305 cipher - seg6: add support for SRv6 End.DT4/DT6 behavior - sctp: Implement RFC 6951: UDP Encapsulation of SCTP - ppp_generic: add ability to bridge channels directly - bridge: Connectivity Fault Management (CFM) support as is defined in IEEE 802.1Q section 12.14. Drivers: - mlx5: make use of the new auxiliary bus to organize the driver internals - mlx5: more accurate port TX timestamping support - mlxsw: - improve the efficiency of offloaded next hop updates by using the new nexthop object API - support blackhole nexthops - support IEEE 802.1ad (Q-in-Q) bridging - rtw88: major bluetooth co-existance improvements - iwlwifi: support new 6 GHz frequency band - ath11k: Fast Initial Link Setup (FILS) - mt7915: dual band concurrent (DBDC) support - net: ipa: add basic support for IPA v4.5 Refactor: - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej Siewior - phy: add support for shared interrupts; get rid of multiple driver APIs and have the drivers write a full IRQ handler, slight growth of driver code should be compensated by the simpler API which also allows shared IRQs - add common code for handling netdev per-cpu counters - move TX packet re-allocation from Ethernet switch tag drivers to a central place - improve efficiency and rename nla_strlcpy - number of W=1 warning cleanups as we now catch those in a patchwork build bot Old code removal: - wan: delete the DLCI / SDLA drivers - wimax: move to staging - wifi: remove old WDS wifi bridging support" * tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits) net: hns3: fix expression that is currently always true net: fix proc_fs init handling in af_packet and tls nfc: pn533: convert comma to semicolon af_vsock: Assign the vsock transport considering the vsock address flags af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path vsock_addr: Check for supported flag values vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag vm_sockets: Add flags field in the vsock address data structure net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context nfc: s3fwrn5: Release the nfc firmware net: vxget: clean up sparse warnings mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3 mlxsw: spectrum_router_xm: Introduce basic XM cache flushing mlxsw: reg: Add Router LPM Cache Enable Register mlxsw: reg: Add Router LPM Cache ML Delete Register mlxsw: spectrum_router_xm: Implement L-value tracking for M-index mlxsw: reg: Add XM Router M Table Register ...
2020-12-14Merge tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linuxLinus Torvalds1-7/+4
Pull misc fixes from Christian Brauner: "This contains several fixes which felt worth being combined into a single branch: - Use put_nsproxy() instead of open-coding it switch_task_namespaces() - Kirill's work to unify lifecycle management for all namespaces. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This work allows us to unify the type of the counters and reduces maintenance cost by moving the counter in one place and indicating that basic lifetime management is identical for all namespaces. - Peilin's fix adding three byte padding to Dmitry's PTRACE_GET_SYSCALL_INFO uapi struct to prevent an info leak. - Two smal patches to convert from the /* fall through */ comment annotation to the fallthrough keyword annotation which I had taken into my branch and into -next before df561f6688fe ("treewide: Use fallthrough pseudo-keyword") made it upstream which fixed this tree-wide. Since I didn't want to invalidate all testing for other commits I didn't rebase and kept them" * tag 'fixes-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: nsproxy: use put_nsproxy() in switch_task_namespaces() sys: Convert to the new fallthrough notation signal: Convert to the new fallthrough notation time: Use generic ns_common::count cgroup: Use generic ns_common::count mnt: Use generic ns_common::count user: Use generic ns_common::count pid: Use generic ns_common::count ipc: Use generic ns_common::count uts: Use generic ns_common::count net: Use generic ns_common::count ns: Add a common refcount into ns_common ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info()
2020-12-01netfilter: nfnl_acct: remove data from struct netWang Shanker1-3/+0
This patch removes nfnl_acct_list from struct net to reduce the default memory footprint for the netns structure. Signed-off-by: Miao Wang <shankerwangmiao@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-09-30bpf, net: Rework cookie generator as per-cpu oneDaniel Borkmann1-1/+1
With its use in BPF, the cookie generator can be called very frequently in particular when used out of cgroup v2 hooks (e.g. connect / sendmsg) and attached to the root cgroup, for example, when used in v1/v2 mixed environments. In particular, when there's a high churn on sockets in the system there can be many parallel requests to the bpf_get_socket_cookie() and bpf_get_netns_cookie() helpers which then cause contention on the atomic counter. As similarly done in f991bd2e1421 ("fs: introduce a per-cpu last_ino allocator"), add a small helper library that both can use for the 64 bit counters. Given this can be called from different contexts, we also need to deal with potential nested calls even though in practice they are considered extremely rare. One idea as suggested by Eric Dumazet was to use a reverse counter for this situation since we don't expect 64 bit overflows anyways; that way, we can avoid bigger gaps in the 64 bit counter space compared to just batch-wise increase. Even on machines with small number of cores (e.g. 4) the cookie generation shrinks from min/max/med/avg (ns) of 22/50/40/38.9 down to 10/35/14/17.3 when run in parallel from multiple CPUs. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Link: https://lore.kernel.org/bpf/8a80b8d27d3c49f9a14e1d5213c19d8be87d1dc8.1601477936.git.daniel@iogearbox.net
2020-08-19net: Use generic ns_common::countChristian Brauner1-7/+4
Switch over network namespaces to use the newly introduced common lifetime counter. Network namespaces have an additional counter named "passive". This counter does not guarantee that the network namespace is not already de-initialized and so isn't concerned with the actual lifetime of the network namespace; only the "count" counter is. So the latter is moved into struct ns_common. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> [christian.brauner@ubuntu.com: rewrite commit] Link: https://lore.kernel.org/r/159644977635.604812.1319877322927063560.stgit@localhost.localdomain Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-06-01net: Introduce netns_bpf for BPF programs attached to netnsJakub Sitnicki1-1/+3
In order to: (1) attach more than one BPF program type to netns, or (2) support attaching BPF programs to netns with bpf_link, or (3) support multi-prog attach points for netns we will need to keep more state per netns than a single pointer like we have now for BPF flow dissector program. Prepare for the above by extracting netns_bpf that is part of struct net, for storing all state related to BPF programs attached to netns. Turn flow dissector callbacks for querying/attaching/detaching a program into generic ones that operate on netns_bpf. Next patch will move the generic callbacks into their own module. This is similar to how it is organized for cgroup with cgroup_bpf. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20200531082846.2117903-3-jakub@cloudflare.com
2020-05-01ipv6: Use global sernum for dst validation with nexthop objectsDavid Ahern1-0/+7
Nik reported a bug with pcpu dst cache when nexthop objects are used illustrated by the following: $ ip netns add foo $ ip -netns foo li set lo up $ ip -netns foo addr add 2001:db8:11::1/128 dev lo $ ip netns exec foo sysctl net.ipv6.conf.all.forwarding=1 $ ip li add veth1 type veth peer name veth2 $ ip li set veth1 up $ ip addr add 2001:db8:10::1/64 dev veth1 $ ip li set dev veth2 netns foo $ ip -netns foo li set veth2 up $ ip -netns foo addr add 2001:db8:10::2/64 dev veth2 $ ip -6 nexthop add id 100 via 2001:db8:10::2 dev veth1 $ ip -6 route add 2001:db8:11::1/128 nhid 100 Create a pcpu entry on cpu 0: $ taskset -a -c 0 ip -6 route get 2001:db8:11::1 Re-add the route entry: $ ip -6 ro del 2001:db8:11::1 $ ip -6 route add 2001:db8:11::1/128 nhid 100 Route get on cpu 0 returns the stale pcpu: $ taskset -a -c 0 ip -6 route get 2001:db8:11::1 RTNETLINK answers: Network is unreachable While cpu 1 works: $ taskset -a -c 1 ip -6 route get 2001:db8:11::1 2001:db8:11::1 from :: via 2001:db8:10::2 dev veth1 src 2001:db8:10::1 metric 1024 pref medium Conversion of FIB entries to work with external nexthop objects missed an important difference between IPv4 and IPv6 - how dst entries are invalidated when the FIB changes. IPv4 has a per-network namespace generation id (rt_genid) that is bumped on changes to the FIB. Checking if a dst_entry is still valid means comparing rt_genid in the rtable to the current value of rt_genid for the namespace. IPv6 also has a per network namespace counter, fib6_sernum, but the count is saved per fib6_node. With the per-node counter only dst_entries based on fib entries under the node are invalidated when changes are made to the routes - limiting the scope of invalidations. IPv6 uses a reference in the rt6_info, 'from', to track the corresponding fib entry used to create the dst_entry. When validating a dst_entry, the 'from' is used to backtrack to the fib6_node and check the sernum of it to the cookie passed to the dst_check operation. With the inline format (nexthop definition inline with the fib6_info), dst_entries cached in the fib6_nh have a 1:1 correlation between fib entries, nexthop data and dst_entries. With external nexthops, IPv6 looks more like IPv4 which means multiple fib entries across disparate fib6_nodes can all reference the same fib6_nh. That means validation of dst_entries based on external nexthops needs to use the IPv4 format - the per-network namespace counter. Add sernum to rt6_info and set it when creating a pcpu dst entry. Update rt6_get_cookie to return sernum if it is set and update dst_check for IPv6 to look for sernum set and based the check on it if so. Finally, rt6_get_pcpu_route needs to validate the cached entry before returning a pcpu entry (similar to the rt_cache_valid calls in __mkroute_input and __mkroute_output for IPv4). This problem only affects routes using the new, external nexthops. Thanks to the kbuild test robot for catching the IS_ENABLED needed around rt_genid_ipv6 before I sent this out. Fixes: 5b98324ebe29 ("ipv6: Allow routes to use nexthop objects") Reported-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@kernel.org> Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Tested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-30bpf, net: Fix build issue when net ns not configuredDaniel Borkmann1-7/+2
Fix a redefinition of 'net_gen_cookie' error that was overlooked when net ns is not configured. Fixes: f318903c0bf4 ("bpf: Add netns cookie and enable it for bpf cgroup hooks") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2020-03-27bpf: Add netns cookie and enable it for bpf cgroup hooksDaniel Borkmann1-0/+10
In Cilium we're mainly using BPF cgroup hooks today in order to implement kube-proxy free Kubernetes service translation for ClusterIP, NodePort (*), ExternalIP, and LoadBalancer as well as HostPort mapping [0] for all traffic between Cilium managed nodes. While this works in its current shape and avoids packet-level NAT for inter Cilium managed node traffic, there is one major limitation we're facing today, that is, lack of netns awareness. In Kubernetes, the concept of Pods (which hold one or multiple containers) has been built around network namespaces, so while we can use the global scope of attaching to root BPF cgroup hooks also to our advantage (e.g. for exposing NodePort ports on loopback addresses), we also have the need to differentiate between initial network namespaces and non-initial one. For example, ExternalIP services mandate that non-local service IPs are not to be translated from the host (initial) network namespace as one example. Right now, we have an ugly work-around in place where non-local service IPs for ExternalIP services are not xlated from connect() and friends BPF hooks but instead via less efficient packet-level NAT on the veth tc ingress hook for Pod traffic. On top of determining whether we're in initial or non-initial network namespace we also have a need for a socket-cookie like mechanism for network namespaces scope. Socket cookies have the nice property that they can be combined as part of the key structure e.g. for BPF LRU maps without having to worry that the cookie could be recycled. We are planning to use this for our sessionAffinity implementation for services. Therefore, add a new bpf_get_netns_cookie() helper which would resolve both use cases at once: bpf_get_netns_cookie(NULL) would provide the cookie for the initial network namespace while passing the context instead of NULL would provide the cookie from the application's network namespace. We're using a hole, so no size increase; the assignment happens only once. Therefore this allows for a comparison on initial namespace as well as regular cookie usage as we have today with socket cookies. We could later on enable this helper for other program types as well as we would see need. (*) Both externalTrafficPolicy={Local|Cluster} types [0] https://github.com/cilium/cilium/blob/master/bpf/bpf_sock.c Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/c47d2346982693a9cf9da0e12690453aded4c788.1585323121.git.daniel@iogearbox.net
2020-01-17netns: Constify exported functionsGuillaume Nault1-5/+5
Mark function parameters as 'const' where possible. Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-1/+1
The only slightly tricky merge conflict was the netdevsim because the mutex locking fix overlapped a lot of driver reload reorganization. The rest were (relatively) trivial in nature. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-25netns: fix GFP flags in rtnl_net_notifyid()Guillaume Nault1-1/+1
In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances, but there are a few paths calling rtnl_net_notifyid() from atomic context or from RCU critical sections. The later also precludes the use of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new() call is wrong too, as it uses GFP_KERNEL unconditionally. Therefore, we need to pass the GFP flags as parameter and propagate it through function calls until the proper flags can be determined. In most cases, GFP_KERNEL is fine. The exceptions are: * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump() indirectly call rtnl_net_notifyid() from RCU critical section, * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as parameter. Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used by nlmsg_new(). The function is allowed to sleep, so better make the flags consistent with the ones used in the following ovs_vport_cmd_fill_info() call. Found by code inspection. Fixes: 9a9634545c70 ("netns: notify netns id events") Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-8/+17
Several cases of overlapping changes which were for the most part trivially resolvable. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-19net: reorder 'struct net' fields to avoid false sharingEric Dumazet1-8/+17
Intel test robot reported a ~7% regression on TCP_CRR tests that they bisected to the cited commit. Indeed, every time a new TCP socket is created or deleted, the atomic counter net->count is touched (via get_net(net) and put_net(net) calls) So cpus might have to reload a contended cache line in net_hash_mix(net) calls. We need to reorder 'struct net' fields to move @hash_mix in a read mostly cache line. We move in the first cache line fields that can be dirtied often. We probably will have to address in a followup patch the __randomize_layout that was added in linux-4.13, since this might break our placement choices. Fixes: 355b98553789 ("netns: provide pure entropy for net_hash_mix()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02net: introduce per-netns netdevice notifiersJiri Pirko1-0/+3
Often the code for example in drivers is interested in getting notifier call only from certain network namespace. In addition to the existing global netdevice notifier chain introduce per-netns chains and allow users to register to that. Eventually this would eliminate unnecessary overhead in case there are many netdevices in many network namespaces. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02net: push loops and nb calls into helper functionsJiri Pirko1-1/+2
Push iterations over net namespaces and netdevices from register_netdevice_notifier() and unregister_netdevice_notifier() into helper functions. Along with that introduce continue_reverse macros to make the code a bit nicer allowing to get rid of "last" marks. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-3/+0
Pull networking updates from David Miller: 1) Support IPV6 RA Captive Portal Identifier, from Maciej Żenczykowski. 2) Use bio_vec in the networking instead of custom skb_frag_t, from Matthew Wilcox. 3) Make use of xmit_more in r8169 driver, from Heiner Kallweit. 4) Add devmap_hash to xdp, from Toke Høiland-Jørgensen. 5) Support all variants of 5750X bnxt_en chips, from Michael Chan. 6) More RTNL avoidance work in the core and mlx5 driver, from Vlad Buslov. 7) Add TCP syn cookies bpf helper, from Petar Penkov. 8) Add 'nettest' to selftests and use it, from David Ahern. 9) Add extack support to drop_monitor, add packet alert mode and support for HW drops, from Ido Schimmel. 10) Add VLAN offload to stmmac, from Jose Abreu. 11) Lots of devm_platform_ioremap_resource() conversions, from YueHaibing. 12) Add IONIC driver, from Shannon Nelson. 13) Several kTLS cleanups, from Jakub Kicinski. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1930 commits) mlxsw: spectrum_buffers: Add the ability to query the CPU port's shared buffer mlxsw: spectrum: Register CPU port with devlink mlxsw: spectrum_buffers: Prevent changing CPU port's configuration net: ena: fix incorrect update of intr_delay_resolution net: ena: fix retrieval of nonadaptive interrupt moderation intervals net: ena: fix update of interrupt moderation register net: ena: remove all old adaptive rx interrupt moderation code from ena_com net: ena: remove ena_restore_ethtool_params() and relevant fields net: ena: remove old adaptive interrupt moderation code from ena_netdev net: ena: remove code duplication in ena_com_update_nonadaptive_moderation_interval _*() net: ena: enable the interrupt_moderation in driver_supported_features net: ena: reimplement set/get_coalesce() net: ena: switch to dim algorithm for rx adaptive interrupt moderation net: ena: add intr_moder_rx_interval to struct ena_com_dev and use it net: phy: adin: implement Energy Detect Powerdown mode via phy-tunable ethtool: implement Energy Detect Powerdown support via phy-tunable xen-netfront: do not assume sk_buff_head list is empty in error handling s390/ctcm: Delete unnecessary checks before the macro call “dev_kfree_skb” net: ena: don't wake up tx queue when down drop_monitor: Better sanitize notified packets ...
2019-09-18Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds1-0/+3
Pull crypto updates from Herbert Xu: "API: - Add the ability to abort a skcipher walk. Algorithms: - Fix XTS to actually do the stealing. - Add library helpers for AES and DES for single-block users. - Add library helpers for SHA256. - Add new DES key verification helper. - Add surrounding bits for ESSIV generator. - Add accelerations for aegis128. - Add test vectors for lzo-rle. Drivers: - Add i.MX8MQ support to caam. - Add gcm/ccm/cfb/ofb aes support in inside-secure. - Add ofb/cfb aes support in media-tek. - Add HiSilicon ZIP accelerator support. Others: - Fix potential race condition in padata. - Use unbound workqueues in padata" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (311 commits) crypto: caam - Cast to long first before pointer conversion crypto: ccree - enable CTS support in AES-XTS crypto: inside-secure - Probe transform record cache RAM sizes crypto: inside-secure - Base RD fetchcount on actual RD FIFO size crypto: inside-secure - Base CD fetchcount on actual CD FIFO size crypto: inside-secure - Enable extended algorithms on newer HW crypto: inside-secure: Corrected configuration of EIP96_TOKEN_CTRL crypto: inside-secure - Add EIP97/EIP197 and endianness detection padata: remove cpu_index from the parallel_queue padata: unbind parallel jobs from specific CPUs padata: use separate workqueues for parallel and serial work padata, pcrypt: take CPU hotplug lock internally in padata_alloc_possible crypto: pcrypt - remove padata cpumask notifier padata: make padata_do_parallel find alternate callback CPU workqueue: require CPU hotplug read exclusion for apply_workqueue_attrs workqueue: unconfine alloc/apply/free_workqueue_attrs() padata: allocate workqueue internally arm64: dts: imx8mq: Add CAAM node random: Use wait_event_freezable() in add_hwgenerator_randomness() crypto: ux500 - Fix COMPILE_TEST warnings ...
2019-09-07net: fib_notifier: move fib_notifier_ops from struct net into per-net structJiri Pirko1-3/+0
No need for fib_notifier_ops to be in struct net. It is used only by fib_notifier as a private data. Use net_generic to introduce per-net fib_notifier struct and move fib_notifier_ops there. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-21trivial: netns: fix typo in 'struct net.passive' descriptionMike Rapoport1-1/+1
Replace 'decided' with 'decide' so that comment would be /* To decide when the network namespace should be freed. */ Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-09sock: make cookie generation global instead of per netnsDaniel Borkmann1-1/+0
Generating and retrieving socket cookies are a useful feature that is exposed to BPF for various program types through bpf_get_socket_cookie() helper. The fact that the cookie counter is per netns is quite a limitation for BPF in practice in particular for programs in host namespace that use socket cookies as part of a map lookup key since they will be causing socket cookie collisions e.g. when attached to BPF cgroup hooks or cls_bpf on tc egress in host namespace handling container traffic from veth or ipvlan devices with peer in different netns. Change the counter to be global instead. Socket cookie consumers must assume the value as opqaue in any case. Not every socket must have a cookie generated and knowledge of the counter value itself does not provide much value either way hence conversion to global is fine. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Cc: Martynas Pumputis <m@lambda.lt> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-26crypto: user - make NETLINK_CRYPTO work inside netnsOndrej Mosnacek1-0/+3
Currently, NETLINK_CRYPTO works only in the init network namespace. It doesn't make much sense to cut it out of the other network namespaces, so do the minor plumbing work necessary to make it work in any network namespace. Code inspired by net/core/sock_diag.c. Tested using kcapi-dgst from libkcapi [1]: Before: # unshare -n kcapi-dgst -c sha256 </dev/null | wc -c libkcapi - Error: Netlink error: sendmsg failed libkcapi - Error: Netlink error: sendmsg failed libkcapi - Error: NETLINK_CRYPTO: cannot obtain cipher information for hmac(sha512) (is required crypto_user.c patch missing? see documentation) 0 After: # unshare -n kcapi-dgst -c sha256 </dev/null | wc -c 32 [1] https://github.com/smuellerDD/libkcapi Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-0/+7
Pull networking updates from David Miller: "Some highlights from this development cycle: 1) Big refactoring of ipv6 route and neigh handling to support nexthop objects configurable as units from userspace. From David Ahern. 2) Convert explored_states in BPF verifier into a hash table, significantly decreased state held for programs with bpf2bpf calls, from Alexei Starovoitov. 3) Implement bpf_send_signal() helper, from Yonghong Song. 4) Various classifier enhancements to mvpp2 driver, from Maxime Chevallier. 5) Add aRFS support to hns3 driver, from Jian Shen. 6) Fix use after free in inet frags by allocating fqdirs dynamically and reworking how rhashtable dismantle occurs, from Eric Dumazet. 7) Add act_ctinfo packet classifier action, from Kevin Darbyshire-Bryant. 8) Add TFO key backup infrastructure, from Jason Baron. 9) Remove several old and unused ISDN drivers, from Arnd Bergmann. 10) Add devlink notifications for flash update status to mlxsw driver, from Jiri Pirko. 11) Lots of kTLS offload infrastructure fixes, from Jakub Kicinski. 12) Add support for mv88e6250 DSA chips, from Rasmus Villemoes. 13) Various enhancements to ipv6 flow label handling, from Eric Dumazet and Willem de Bruijn. 14) Support TLS offload in nfp driver, from Jakub Kicinski, Dirk van der Merwe, and others. 15) Various improvements to axienet driver including converting it to phylink, from Robert Hancock. 16) Add PTP support to sja1105 DSA driver, from Vladimir Oltean. 17) Add mqprio qdisc offload support to dpaa2-eth, from Ioana Radulescu. 18) Add devlink health reporting to mlx5, from Moshe Shemesh. 19) Convert stmmac over to phylink, from Jose Abreu. 20) Add PTP PHC (Physical Hardware Clock) support to mlxsw, from Shalom Toledo. 21) Add nftables SYNPROXY support, from Fernando Fernandez Mancera. 22) Convert tcp_fastopen over to use SipHash, from Ard Biesheuvel. 23) Track spill/fill of constants in BPF verifier, from Alexei Starovoitov. 24) Support bounded loops in BPF, from Alexei Starovoitov. 25) Various page_pool API fixes and improvements, from Jesper Dangaard Brouer. 26) Just like ipv4, support ref-countless ipv6 route handling. From Wei Wang. 27) Support VLAN offloading in aquantia driver, from Igor Russkikh. 28) Add AF_XDP zero-copy support to mlx5, from Maxim Mikityanskiy. 29) Add flower GRE encap/decap support to nfp driver, from Pieter Jansen van Vuuren. 30) Protect against stack overflow when using act_mirred, from John Hurley. 31) Allow devmap map lookups from eBPF, from Toke Høiland-Jørgensen. 32) Use page_pool API in netsec driver, Ilias Apalodimas. 33) Add Google gve network driver, from Catherine Sullivan. 34) More indirect call avoidance, from Paolo Abeni. 35) Add kTLS TX HW offload support to mlx5, from Tariq Toukan. 36) Add XDP_REDIRECT support to bnxt_en, from Andy Gospodarek. 37) Add MPLS manipulation actions to TC, from John Hurley. 38) Add sending a packet to connection tracking from TC actions, and then allow flower classifier matching on conntrack state. From Paul Blakey. 39) Netfilter hw offload support, from Pablo Neira Ayuso" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2080 commits) net/mlx5e: Return in default case statement in tx_post_resync_params mlx5: Return -EINVAL when WARN_ON_ONCE triggers in mlx5e_tls_resync(). net: dsa: add support for BRIDGE_MROUTER attribute pkt_sched: Include const.h net: netsec: remove static declaration for netsec_set_tx_de() net: netsec: remove superfluous if statement netfilter: nf_tables: add hardware offload support net: flow_offload: rename tc_cls_flower_offload to flow_cls_offload net: flow_offload: add flow_block_cb_is_busy() and use it net: sched: remove tcf block API drivers: net: use flow block API net: sched: use flow block API net: flow_offload: add flow_block_cb_{priv, incref, decref}() net: flow_offload: add list handling functions net: flow_offload: add flow_block_cb_alloc() and flow_block_cb_free() net: flow_offload: rename TCF_BLOCK_BINDER_TYPE_* to FLOW_BLOCK_BINDER_TYPE_* net: flow_offload: rename TC_BLOCK_{UN}BIND to FLOW_BLOCK_{UN}BIND net: flow_offload: add flow_block_cb_setup_simple() net: hisilicon: Add an tx_desc to adapt HI13X1_GMAC net: hisilicon: Add an rx_desc to adapt HI13X1_GMAC ...
2019-06-26keys: Network namespace domain tagDavid Howells1-0/+3
Create key domain tags for network namespaces and make it possible to automatically tag keys that are used by networked services (e.g. AF_RXRPC, AFS, DNS) with the default network namespace if not set by the caller. This allows keys with the same description but in different namespaces to coexist within a keyring. Signed-off-by: David Howells <dhowells@redhat.com> cc: netdev@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-afs@lists.infradead.org
2019-06-19netns: add pre_exit method to struct pernet_operationsEric Dumazet1-0/+5
Current struct pernet_operations exit() handlers are highly discouraged to call synchronize_rcu(). There are cases where we need them, and exit_batch() does not help the common case where a single netns is dismantled. This patch leverages the existing synchronize_rcu() call in cleanup_net() Calling optional ->pre_exit() method before ->exit() or ->exit_batch() allows to benefit from a single synchronize_rcu() call. Note that the synchronize_rcu() calls added in this patch are only in error paths or slow paths. Tested: $ time for i in {1..1000}; do unshare -n /bin/false;done real 0m2.612s user 0m0.171s sys 0m2.216s Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-28net: Initial nexthop codeDavid Ahern1-0/+2
Barebones start point for nexthops. Implementation for RTM commands, notifications, management of rbtree for holding nexthops by id, and kernel side data structures for nexthops and nexthop config. Nexthops are maintained in an rbtree sorted by id. Similar to routes, nexthops are configured per namespace using netns_nexthop struct added to struct net. Nexthop notifications are sent when a nexthop is added or deleted, but NOT if the delete is due to a device event or network namespace teardown (which also involves device events). Applications are expected to use the device down event to flush nexthops and any routes used by the nexthops. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-28netns: provide pure entropy for net_hash_mix()Eric Dumazet1-0/+1
net_hash_mix() currently uses kernel address of a struct net, and is used in many places that could be used to reveal this address to a patient attacker, thus defeating KASLR, for the typical case (initial net namespace, &init_net is not dynamically allocated) I believe the original implementation tried to avoid spending too many cycles in this function, but security comes first. Also provide entropy regardless of CONFIG_NET_NS. Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Benny Pinkas <benny@pinkas.net> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-25net: xsk: track AF_XDP sockets on a per-netns listBjörn Töpel1-0/+4
Track each AF_XDP socket in a per-netns list. This will be used later by the sock_diag interface for querying sockets from userspace. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-14flow_dissector: implements flow dissector BPF hookPetar Penkov1-0/+3
Adds a hook for programs of type BPF_PROG_TYPE_FLOW_DISSECTOR and attach type BPF_FLOW_DISSECTOR that is executed in the flow dissector path. The BPF program is per-network namespace. Signed-off-by: Petar Penkov <ppenkov@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-20net: create reusable function for getting ownership info of sysfs inodesTyler Hicks1-0/+10
Make net_ns_get_ownership() reusable by networking code outside of core. This is useful, for example, to allow bridge related sysfs files to be owned by container root. Add a function comment since this is a potentially dangerous function to use given the way that kobject_get_ownership() works by initializing uid and gid before calling .get_ownership(). Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-18netfilter: ipv6: nf_defrag: reduce struct net memory wasteEric Dumazet1-0/+1
It is a waste of memory to use a full "struct netns_sysctl_ipv6" while only one pointer is really used, considering netns_sysctl_ipv6 keeps growing. Also, since "struct netns_frags" has cache line alignment, it is better to move the frags_hdr pointer outside, otherwise we spend a full cache line for this pointer. This saves 192 bytes of memory per netns. Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-03-29net: Introduce net_rwsem to protect net_namespace_listKirill Tkhai1-0/+1
rtnl_lock() is used everywhere, and contention is very high. When someone wants to iterate over alive net namespaces, he/she has no a possibility to do that without exclusive lock. But the exclusive rtnl_lock() in such places is overkill, and it just increases the contention. Yes, there is already for_each_net_rcu() in kernel, but it requires rcu_read_lock(), and this can't be sleepable. Also, sometimes it may be need really prevent net_namespace_list growth, so for_each_net_rcu() is not fit there. This patch introduces new rw_semaphore, which will be used instead of rtnl_mutex to protect net_namespace_list. It is sleepable and allows not-exclusive iterations over net namespaces list. It allows to stop using rtnl_lock() in several places (what is made in next patches) and makes less the time, we keep rtnl_mutex. Here we just add new lock, while the explanation of we can remove rtnl_lock() there are in next patches. Fine grained locks generally are better, then one big lock, so let's do that with net_namespace_list, while the situation allows that. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Add more commentsKirill Tkhai1-0/+4
This adds comments to different places to improve readability. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Rename net_sem to pernet_ops_rwsemKirill Tkhai1-5/+7
net_sem is some undefined area name, so it will be better to make the area more defined. Rename it to pernet_ops_rwsem for better readability and better intelligibility. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>