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2017-08-09net: call newid/getid without rtnl mutex heldFlorian Westphal
Both functions take nsid_lock and don't rely on rtnl lock. 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>
2017-08-09rtnetlink: make rtnl_register accept a flags parameterFlorian Westphal
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>
2017-07-01net: convert net.passive from atomic_t to refcount_tReshetova, Elena
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>
2017-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree. This batch contains connection tracking updates for the cleanup iteration path, patches from Florian Westphal: X) Skip unconfirmed conntracks in nf_ct_iterate_cleanup_net(), just set dying bit to let the CPU release them. X) Add nf_ct_iterate_destroy() to be used on module removal, to kill conntrack from all namespace. X) Restart iteration on hashtable resizing, since both may occur at the same time. X) Use the new nf_ct_iterate_destroy() to remove conntrack with NAT mapping on module removal. X) Use nf_ct_iterate_destroy() to remove conntrack entries helper module removal, from Liping Zhang. X) Use nf_ct_iterate_cleanup_net() to remove the timeout extension if user requests this, also from Liping. X) Add net_ns_barrier() and use it from FTP helper, so make sure no concurrent namespace removal happens at the same time while the helper module is being removed. X) Use NFPROTO_MAX in layer 3 conntrack protocol array, to reduce module size. Same thing in nf_tables. Updates for the nf_tables infrastructure: X) Prepare usage of the extended ACK reporting infrastructure for nf_tables. X) Remove unnecessary forward declaration in nf_tables hash set. X) Skip set size estimation if number of element is not specified. X) Changes to accomodate a (faster) unresizable hash set implementation, for anonymous sets and dynamic size fixed sets with no timeouts. X) Faster lookup function for unresizable hash table for 2 and 4 bytes key. And, finally, a bunch of asorted small updates and cleanups: X) Do not hold reference to netdev from ipt_CLUSTER, instead subscribe to device events and look up for index from the packet path, this is fixing an issue that is present since the very beginning, patch from Xin Long. X) Use nf_register_net_hook() in ipt_CLUSTER, from Florian Westphal. X) Use ebt_invalid_target() whenever possible in the ebtables tree, from Gao Feng. X) Calm down compilation warning in nf_dup infrastructure, patch from stephen hemminger. X) Statify functions in nftables rt expression, also from stephen. X) Update Makefile to use canonical method to specify nf_tables-objs. From Jike Song. X) Use nf_conntrack_helpers_register() in amanda and H323. X) Space cleanup for ctnetlink, from linzhang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-19netns: add and use net_ns_barrierFlorian Westphal
Quoting Joe Stringer: If a user loads nf_conntrack_ftp, sends FTP traffic through a network namespace, destroys that namespace then unloads the FTP helper module, then the kernel will crash. Events that lead to the crash: 1. conntrack is created with ftp helper in netns x 2. This netns is destroyed 3. netns destruction is scheduled 4. netns destruction wq starts, removes netns from global list 5. ftp helper is unloaded, which resets all helpers of the conntracks via for_each_net() but because netns is already gone from list the for_each_net() loop doesn't include it, therefore all of these conntracks are unaffected. 6. helper module unload finishes 7. netns wq invokes destructor for rmmod'ed helper CC: "Eric W. Biederman" <ebiederm@xmission.com> Reported-by: Joe Stringer <joe@ovn.org> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-06-10netns: fix error code when the nsid is already usedNicolas Dichtel
When the user tries to assign a specific nsid, idr_alloc() is called with the range [nsid, nsid+1]. If this nsid is already used, idr_alloc() returns ENOSPC (No space left on device). In our case, it's better to return EEXIST to make it clear that the nsid is not available. CC: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10netns: define extack error msg for nsis cmdsNicolas Dichtel
It helps the user to identify errors. CC: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25net: move somaxconn init from sysctl codeRoman Kapl
The default value for somaxconn is set in sysctl_core_net_init(), but this function is not called when kernel is configured without CONFIG_SYSCTL. This results in the kernel not being able to accept TCP connections, because the backlog has zero size. Usually, the user ends up with: "TCP: request_sock_TCP: Possible SYN flooding on port 7. Dropping request. Check SNMP counters." If SYN cookies are not enabled the connection is rejected. Before ef547f2ac16 (tcp: remove max_qlen_log), the effects were less severe, because the backlog was always at least eight slots long. Signed-off-by: Roman Kapl <roman.kapl@sysgo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-30net: Initialise init_net.count to 1David Howells
Initialise init_net.count to 1 for its pointer from init_nsproxy lest someone tries to do a get_net() and a put_net() in a process in which current->ns_proxy->net_ns points to the initial network namespace. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17net: rtnetlink: plumb extended ack to doit functionDavid Ahern
Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse for doit functions that call it directly. This is the first step to using extended error reporting in rtnetlink. >From here individual subsystems can be updated to set netlink_ext_ack as needed. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-02sched/headers: Prepare to move the task_lock()/unlock() APIs to ↵Ingo Molnar
<linux/sched/task.h> But first update the code that uses these facilities with the new header. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-14Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "After the small number of patches for v4.9, we've got a much bigger pile for v4.10. The bulk of these patches involve a rework of the audit backlog queue to enable us to move the netlink multicasting out of the task/thread that generates the audit record and into the kernel thread that emits the record (just like we do for the audit unicast to auditd). While we were playing with the backlog queue(s) we fixed a number of other little problems with the code, and from all the testing so far things look to be in much better shape now. Doing this also allowed us to re-enable disabling IRQs for some netns operations ("netns: avoid disabling irq for netns id"). The remaining patches fix some small problems that are well documented in the commit descriptions, as well as adding session ID filtering support" * 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit: audit: use proper refcount locking on audit_sock netns: avoid disabling irq for netns id audit: don't ever sleep on a command record/message audit: handle a clean auditd shutdown with grace audit: wake up kauditd_thread after auditd registers audit: rework audit_log_start() audit: rework the audit queue handling audit: rename the queues and kauditd related functions audit: queue netlink multicast sends just like we do for unicast sends audit: fixup audit_init() audit: move kaudit thread start from auditd registration to kaudit init (#2) audit: add support for session ID user filter audit: fix formatting of AUDIT_CONFIG_CHANGE events audit: skip sessionid sentinel value when auto-incrementing audit: tame initialization warning len_abuf in audit_log_execve_info audit: less stack usage for /proc/*/loginuid
2016-12-14netns: avoid disabling irq for netns idPaul Moore
Bring back commit bc51dddf98c9 ("netns: avoid disabling irq for netns id") now that we've fixed some audit multicast issues that caused problems with original attempt. Additional information, and history, can be found in the links below: * https://github.com/linux-audit/audit-kernel/issues/22 * https://github.com/linux-audit/audit-kernel/issues/23 Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-03netns: fix net_generic() "id - 1" bloatAlexey Dobriyan
net_generic() function is both a) inline and b) used ~600 times. It has the following code inside ... ptr = ng->ptr[id - 1]; ... "id" is never compile time constant so compiler is forced to subtract 1. And those decrements or LEA [r32 - 1] instructions add up. We also start id'ing from 1 to catch bugs where pernet sybsystem id is not initialized and 0. This is quite pointless idea (nothing will work or immediate interference with first registered subsystem) in general but it hints what needs to be done for code size reduction. Namely, overlaying allocation of pointer array and fixed part of structure in the beginning and using usual base-0 addressing. Ids are just cookies, their exact values do not matter, so lets start with 3 on x86_64. Code size savings (oh boy): -4.2 KB As usual, ignore the initial compiler stupidity part of the table. add/remove: 0/0 grow/shrink: 12/670 up/down: 89/-4297 (-4208) function old new delta tipc_nametbl_insert_publ 1250 1270 +20 nlmclnt_lookup_host 686 703 +17 nfsd4_encode_fattr 5930 5941 +11 nfs_get_client 1050 1061 +11 register_pernet_operations 333 342 +9 tcf_mirred_init 843 849 +6 tcf_bpf_init 1143 1149 +6 gss_setup_upcall 990 994 +4 idmap_name_to_id 432 434 +2 ops_init 274 275 +1 nfsd_inject_forget_client 259 260 +1 nfs4_alloc_client 612 613 +1 tunnel_key_walker 164 163 -1 ... tipc_bcbase_select_primary 392 360 -32 mac80211_hwsim_new_radio 2808 2767 -41 ipip6_tunnel_ioctl 2228 2186 -42 tipc_bcast_rcv 715 672 -43 tipc_link_build_proto_msg 1140 1089 -51 nfsd4_lock 3851 3796 -55 tipc_mon_rcv 1012 956 -56 Total: Before=156643951, After=156639743, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03netns: add dummy struct inside "struct net_generic"Alexey Dobriyan
This is precursor to fixing "[id - 1]" bloat inside net_generic(). Name "s" is chosen to complement name "u" often used for dummy unions. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03netns: publish net_generic correctlyAlexey Dobriyan
Publishing net_generic pointer is done with silly mistake: new array is published BEFORE setting freshly acquired pernet subsystem pointer. memcpy rcu_assign_pointer kfree_rcu ng->ptr[id - 1] = data; This bug was introduced with commit dec827d174d7f76c457238800183ca864a639365 ("[NETNS]: The generic per-net pointers.") in the glorious days of chopping networking stack into containers proper 8.5 years ago (whee...) How it didn't trigger for so long? Well, you need quite specific set of conditions: *) race window opens once per pernet subsystem addition (read: modprobe or boot) *) not every pernet subsystem is eligible (need ->id and ->size) *) not every pernet subsystem is vulnerable (need incorrect or absense of ordering of register_pernet_sybsys() and actually using net_generic()) *) to hide the bug even more, default is to preallocate 13 pointers which is actually quite a lot. You need IPv6, netfilter, bridging etc together loaded to trigger reallocation in the first place. Trimmed down config are OK. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
All conflicts were simple overlapping changes except perhaps for the Thunder driver. That driver has a change_mtu method explicitly for sending a message to the hardware. If that fails it returns an error. Normally a driver doesn't need an ndo_change_mtu method becuase those are usually just range changes, which are now handled generically. But since this extra operation is needed in the Thunder driver, it has to stay. However, if the message send fails we have to restore the original MTU before the change because the entire call chain expects that if an error is thrown by ndo_change_mtu then the MTU did not change. Therefore code is added to nicvf_change_mtu to remember the original MTU, and to restore it upon nicvf_update_hw_max_frs() failue. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18netns: make struct pernet_operations::id unsigned intAlexey Dobriyan
Make struct pernet_operations::id unsigned. There are 2 reasons to do so: 1) This field is really an index into an zero based array and thus is unsigned entity. Using negative value is out-of-bound access by definition. 2) On x86_64 unsigned 32-bit data which are mixed with pointers via array indexing or offsets added or subtracted to pointers are preffered to signed 32-bit data. "int" being used as an array index needs to be sign-extended to 64-bit before being used. void f(long *p, int i) { g(p[i]); } roughly translates to movsx rsi, esi mov rdi, [rsi+...] call g MOVSX is 3 byte instruction which isn't necessary if the variable is unsigned because x86_64 is zero extending by default. Now, there is net_generic() function which, you guessed it right, uses "int" as an array index: static inline void *net_generic(const struct net *net, int id) { ... ptr = ng->ptr[id - 1]; ... } And this function is used a lot, so those sign extensions add up. Patch snipes ~1730 bytes on allyesconfig kernel (without all junk messing with code generation): add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) Unfortunately some functions actually grow bigger. This is a semmingly random artefact of code generation with register allocator being used differently. gcc decides that some variable needs to live in new r8+ registers and every access now requires REX prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be used which is longer than [r8] However, overall balance is in negative direction: add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) function old new delta nfsd4_lock 3886 3959 +73 tipc_link_build_proto_msg 1096 1140 +44 mac80211_hwsim_new_radio 2776 2808 +32 tipc_mon_rcv 1032 1058 +26 svcauth_gss_legacy_init 1413 1429 +16 tipc_bcbase_select_primary 379 392 +13 nfsd4_exchange_id 1247 1260 +13 nfsd4_setclientid_confirm 782 793 +11 ... put_client_renew_locked 494 480 -14 ip_set_sockfn_get 730 716 -14 geneve_sock_add 829 813 -16 nfsd4_sequence_done 721 703 -18 nlmclnt_lookup_host 708 686 -22 nfsd4_lockt 1085 1063 -22 nfs_get_client 1077 1050 -27 tcf_bpf_init 1106 1076 -30 nfsd4_encode_fattr 5997 5930 -67 Total: Before=154856051, After=154854321, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-17net: check dead netns for peernet2id_alloc()WANG Cong
Andrei reports we still allocate netns ID from idr after we destroy it in cleanup_net(). cleanup_net(): ... idr_destroy(&net->netns_ids); ... list_for_each_entry_reverse(ops, &pernet_list, list) ops_exit_list(ops, &net_exit_list); -> rollback_registered_many() -> rtmsg_ifinfo_build_skb() -> rtnl_fill_ifinfo() -> peernet2id_alloc() After that point we should not even access net->netns_ids, we should check the death of the current netns as early as we can in peernet2id_alloc(). For net-next we can consider to avoid sending rtmsg totally, it is a good optimization for netns teardown path. Fixes: 0c7aecd4bde4 ("netns: add rtnl cmd to add and get peer netns ids") Reported-by: Andrei Vagin <avagin@gmail.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Mostly simple overlapping changes. For example, David Ahern's adjacency list revamp in 'net-next' conflicted with an adjacency list traversal bug fix in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-23net: allow to kill a task which waits net_mutex in copy_new_nsAndrey Vagin
net_mutex can be locked for a long time. It may be because many namespaces are being destroyed or many processes decide to create a network namespace. Both these operations are heavy, so it is better to have an ability to kill a process which is waiting net_mutex. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-22netns: revert "netns: avoid disabling irq for netns id"Paul Moore
This reverts commit bc51dddf98c9 ("netns: avoid disabling irq for netns id") as it was found to cause problems with systems running SELinux/audit, see the mailing list thread below: * http://marc.info/?t=147694653900002&r=1&w=2 Eventually we should be able to reintroduce this code once we have rewritten the audit multicast code to queue messages much the same way we do for unicast messages. A tracking issue for this can be found below: * https://github.com/linux-audit/audit-kernel/issues/23 Reported-by: Stephen Smalley <sds@tycho.nsa.gov> Reported-by: Elad Raz <e@eladraz.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This set of changes is a number of smaller things that have been overlooked in other development cycles focused on more fundamental change. The devpts changes are small things that were a distraction until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an trivial regression fix to autofs for the unprivileged mount changes that went in last cycle. A pair of ioctls has been added by Andrey Vagin making it is possible to discover the relationships between namespaces when referring to them through file descriptors. The big user visible change is starting to add simple resource limits to catch programs that misbehave. With namespaces in general and user namespaces in particular allowing users to use more kinds of resources, it has become important to have something to limit errant programs. Because the purpose of these limits is to catch errant programs the code needs to be inexpensive to use as it always on, and the default limits need to be high enough that well behaved programs on well behaved systems don't encounter them. To this end, after some review I have implemented per user per user namespace limits, and use them to limit the number of namespaces. The limits being per user mean that one user can not exhause the limits of another user. The limits being per user namespace allow contexts where the limit is 0 and security conscious folks can remove from their threat anlysis the code used to manage namespaces (as they have historically done as it root only). At the same time the limits being per user namespace allow other parts of the system to use namespaces. Namespaces are increasingly being used in application sand boxing scenarios so an all or nothing disable for the entire system for the security conscious folks makes increasing use of these sandboxes impossible. There is also added a limit on the maximum number of mounts present in a single mount namespace. It is nontrivial to guess what a reasonable system wide limit on the number of mount structure in the kernel would be, especially as it various based on how a system is using containers. A limit on the number of mounts in a mount namespace however is much easier to understand and set. In most cases in practice only about 1000 mounts are used. Given that some autofs scenarious have the potential to be 30,000 to 50,000 mounts I have set the default limit for the number of mounts at 100,000 which is well above every known set of users but low enough that the mount hash tables don't degrade unreaonsably. These limits are a start. I expect this estabilishes a pattern that other limits for resources that namespaces use will follow. There has been interest in making inotify event limits per user per user namespace as well as interest expressed in making details about what is going on in the kernel more visible" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits) autofs: Fix automounts by using current_real_cred()->uid mnt: Add a per mount namespace limit on the number of mounts netns: move {inc,dec}_net_namespaces into #ifdef nsfs: Simplify __ns_get_path tools/testing: add a test to check nsfs ioctl-s nsfs: add ioctl to get a parent namespace nsfs: add ioctl to get an owning user namespace for ns file descriptor kernel: add a helper to get an owning user namespace for a namespace devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts devpts: Remove sync_filesystems devpts: Make devpts_kill_sb safe if fsi is NULL devpts: Simplify devpts_mount by using mount_nodev devpts: Move the creation of /dev/pts/ptmx into fill_super devpts: Move parse_mount_options into fill_super userns: When the per user per user namespace limit is reached return ENOSPC userns; Document per user per user namespace limits. mntns: Add a limit on the number of mount namespaces. netns: Add a limit on the number of net namespaces cgroupns: Add a limit on the number of cgroup namespaces ipcns: Add a limit on the number of ipc namespaces ...
2016-09-23netns: move {inc,dec}_net_namespaces into #ifdefArnd Bergmann
With the newly enforced limit on the number of namespaces, we get a build warning if CONFIG_NETNS is disabled: net/core/net_namespace.c:273:13: error: 'dec_net_namespaces' defined but not used [-Werror=unused-function] net/core/net_namespace.c:268:24: error: 'inc_net_namespaces' defined but not used [-Werror=unused-function] This moves the two added functions inside the #ifdef that guards their callers. Fixes: 703286608a22 ("netns: Add a limit on the number of net namespaces") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-09-22Merge branch 'nsfs-ioctls' into HEADEric W. Biederman
From: Andrey Vagin <avagin@openvz.org> Each namespace has an owning user namespace and now there is not way to discover these relationships. Pid and user namepaces are hierarchical. There is no way to discover parent-child relationships too. Why we may want to know relationships between namespaces? One use would be visualization, in order to understand the running system. Another would be to answer the question: what capability does process X have to perform operations on a resource governed by namespace Y? One more use-case (which usually called abnormal) is checkpoint/restart. In CRIU we are going to dump and restore nested namespaces. There [1] was a discussion about which interface to choose to determing relationships between namespaces. Eric suggested to add two ioctl-s [2]: > Grumble, Grumble. I think this may actually a case for creating ioctls > for these two cases. Now that random nsfs file descriptors are bind > mountable the original reason for using proc files is not as pressing. > > One ioctl for the user namespace that owns a file descriptor. > One ioctl for the parent namespace of a namespace file descriptor. Here is an implementaions of these ioctl-s. $ man man7/namespaces.7 ... Since Linux 4.X, the following ioctl(2) calls are supported for namespace file descriptors. The correct syntax is: fd = ioctl(ns_fd, ioctl_type); where ioctl_type is one of the following: NS_GET_USERNS Returns a file descriptor that refers to an owning user names‐ pace. NS_GET_PARENT Returns a file descriptor that refers to a parent namespace. This ioctl(2) can be used for pid and user namespaces. For user namespaces, NS_GET_PARENT and NS_GET_USERNS have the same meaning. In addition to generic ioctl(2) errors, the following specific ones can occur: EINVAL NS_GET_PARENT was called for a nonhierarchical namespace. EPERM The requested namespace is outside of the current namespace scope. [1] https://lkml.org/lkml/2016/7/6/158 [2] https://lkml.org/lkml/2016/7/9/101 Changes for v2: * don't return ENOENT for init_user_ns and init_pid_ns. There is nothing outside of the init namespace, so we can return EPERM in this case too. > The fewer special cases the easier the code is to get > correct, and the easier it is to read. // Eric Changes for v3: * rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> Cc: "W. Trevor King" <wking@tremily.us> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@canonical.com>
2016-09-22kernel: add a helper to get an owning user namespace for a namespaceAndrey Vagin
Return -EPERM if an owning user namespace is outside of a process current user namespace. v2: In a first version ns_get_owner returned ENOENT for init_user_ns. This special cases was removed from this version. There is nothing outside of init_user_ns, so we can return EPERM. v3: rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-09-22userns: When the per user per user namespace limit is reached return ENOSPCEric W. Biederman
The current error codes returned when a the per user per user namespace limit are hit (EINVAL, EUSERS, and ENFILE) are wrong. I asked for advice on linux-api and it we made clear that those were the wrong error code, but a correct effor code was not suggested. The best general error code I have found for hitting a resource limit is ENOSPC. It is not perfect but as it is unambiguous it will serve until someone comes up with a better error code. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-09-04netns: avoid disabling irq for netns idWANG Cong
We never read or change netns id in hardirq context, the only place we read netns id in softirq context is in vxlan_xmit(). So, it should be enough to just disable BH. Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-04vxlan: call peernet2id() in fdb notificationWANG Cong
netns id should be already allocated each time we change netns, that is, in dev_change_net_namespace() (more precisely in rtnl_fill_ifinfo()). It is safe to just call peernet2id() here. Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01netns: make nla_policy conststephen hemminger
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-14netns: do not call pernet ops for not yet set up init_net namespaceDmitry Torokhov
When CONFIG_NET_NS is disabled, registering pernet operations causes init() to be called immediately with init_net as an argument. Unfortunately this leads to some pernet ops, such as proc_net_ns_init() to be called too early, when init_net namespace has not been fully initialized. This causes issues when we want to change pernet ops to use more data from the net namespace in question, for example reference user namespace that owns our network namespace. To fix this we could either play game of musical chairs and rearrange init order, or we could do the same as when CONFIG_NET_NS is enabled, and postpone calling pernet ops->init() until namespace is set up properly. Note that we can not simply undo commit ed160e839d2e ("[NET]: Cleanup pernet operation without CONFIG_NET_NS") and use the same implementations for __register_pernet_operations() and __unregister_pernet_operations(), because many pernet ops are marked as __net_initdata and will be discarded, which wreaks havoc on our ops lists. Here we rely on the fact that we only use lists until init_net is fully initialized, which happens much earlier than discarding __net_initdata sections. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08netns: Add a limit on the number of net namespacesEric W. Biederman
Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-05-17netns: make nsid_lock per netWANG Cong
The spinlock is used to protect netns_ids which is per net, so there is no need to use a global spinlock. Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-14netns: fix unbalanced spin_lock on errorNicolas Dichtel
Unlock was missing on error path. Fixes: 95f38411df05 ("netns: use a spin_lock to protect nsid management") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Four minor merge conflicts: 1) qca_spi.c renamed the local variable used for the SPI device from spi_device to spi, meanwhile the spi_set_drvdata() call got moved further up in the probe function. 2) Two changes were both adding new members to codel params structure, and thus we had overlapping changes to the initializer function. 3) 'net' was making a fix to sk_release_kernel() which is completely removed in 'net-next'. 4) In net_namespace.c, the rtnl_net_fill() call for GET operations had the command value fixed, meanwhile 'net-next' adjusted the argument signature a bit. This also matches example merge resolutions posted by Stephen Rothwell over the past two days. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-12netns: return RTM_NEWNSID instead of RTM_GETNSID on a getNicolas Dichtel
Usually, RTM_NEWxxx is returned on a get (same as a dump). Fixes: 0c7aecd4bde4 ("netns: add rtnl cmd to add and get peer netns ids") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netlink: allow to listen "all" netnsNicolas Dichtel
More accurately, listen all netns that have a nsid assigned into the netns where the netlink socket is opened. For this purpose, a netlink socket option is added: NETLINK_LISTEN_ALL_NSID. When this option is set on a netlink socket, this socket will receive netlink notifications from all netns that have a nsid assigned into the netns where the socket has been opened. The nsid is sent to userland via an anscillary data. With this patch, a daemon needs only one socket to listen many netns. This is useful when the number of netns is high. Because 0 is a valid value for a nsid, the field nsid_is_set indicates if the field nsid is valid or not. skb->cb is initialized to 0 on skb allocation, thus we are sure that we will never send a nsid 0 by error to the userland. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netns: use a spin_lock to protect nsid managementNicolas Dichtel
Before this patch, nsid were protected by the rtnl lock. The goal of this patch is to be able to find a nsid without needing to hold the rtnl lock. The next patch will introduce a netlink socket option to listen to all netns that have a nsid assigned into the netns where the socket is opened. Thus, it's important to call rtnl_net_notifyid() outside the spinlock, to avoid a recursive lock (nsid are notified via rtnl). This was the main reason of the previous patch. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netns: notify new nsid outside __peernet2id()Nicolas Dichtel
There is no functional change with this patch. It will ease the refactoring of the locking system that protects nsids and the support of the netlink socket option NETLINK_LISTEN_ALL_NSID. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netns: rename peernet2id() to peernet2id_alloc()Nicolas Dichtel
In a following commit, a new function will be introduced to only lookup for a nsid (no allocation if the nsid doesn't exist). To avoid confusion, the existing function is renamed. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netns: always provide the id to rtnl_net_fill()Nicolas Dichtel
The goal of this commit is to prepare the rework of the locking of nsnid protection. After this patch, rtnl_net_notifyid() will not call anymore __peernet2id(), ie no idr_* operation into this function. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-09netns: returns always an id in __peernet2id()Nicolas Dichtel
All callers of this function expect a nsid, not an error. Thus, returns NETNSA_NSID_NOT_ASSIGNED in case of error so that callers don't have to convert the error to NETNSA_NSID_NOT_ASSIGNED. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16netns: remove duplicated include from net_namespace.cWei Yongjun
Remove duplicated include. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-07netns: allow to dump netns idsNicolas Dichtel
Which this patch, it's possible to dump the list of ids allocated for peer netns. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-07netns: notify netns id eventsNicolas Dichtel
With this patch, netns ids that are created and deleted are advertised into the group RTNLGRP_NSID. Because callers of rtnl_net_notifyid() already know the id of the peer, there is no need to call __peernet2id() in rtnl_net_fill(). Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-07netns: minor cleanup in rtnl_net_getid()Nicolas Dichtel
No need to initialize err, it will be overridden by the value of nlmsg_parse(). Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mellanox/mlx4/cmd.c net/core/fib_rules.c net/ipv4/fib_frontend.c The fib_rules.c and fib_frontend.c conflicts were locking adjustments in 'net' overlapping addition and removal of code in 'net-next'. The mlx4 conflict was a bug fix in 'net' happening in the same place a constant was being replaced with a more suitable macro. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03netns: don't allocate an id for dead netnsNicolas Dichtel
First, let's explain the problem. Suppose you have an ipip interface that stands in the netns foo and its link part in the netns bar (so the netns bar has an nsid into the netns foo). Now, you remove the netns bar: - the bar nsid into the netns foo is removed - the netns exit method of ipip is called, thus our ipip iface is removed: => a netlink message is built in the netns foo to advertise this deletion => this netlink message requests an nsid for bar, thus a new nsid is allocated for bar and never removed. This patch adds a check in peernet2id() so that an id cannot be allocated for a netns which is currently destroyed. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-03Revert "netns: don't clear nsid too early on removal"Nicolas Dichtel
This reverts commit 4217291e592d ("netns: don't clear nsid too early on removal"). This is not the right fix, it introduces races. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>