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2023-12-29genetlink: Use internal flags for multicast groupsIdo Schimmel
As explained in commit e03781879a0d ("drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group"), the "flags" field in the multicast group structure reuses uAPI flags despite the field not being exposed to user space. This makes it impossible to extend its use without adding new uAPI flags, which is inappropriate for internal kernel checks. Solve this by adding internal flags (i.e., "GENL_MCAST_*") and convert the existing users to use them instead of the uAPI flags. Tested using the reproducers in commit 44ec98ea5ea9 ("psample: Require 'CAP_NET_ADMIN' when joining "packets" group") and commit e03781879a0d ("drop_monitor: Require 'CAP_SYS_ADMIN' when joining "events" group"). No functional changes intended. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-07psample: Require 'CAP_NET_ADMIN' when joining "packets" groupIdo Schimmel
The "psample" generic netlink family notifies sampled packets over the "packets" multicast group. This is problematic since by default generic netlink allows non-root users to listen to these notifications. Fix by marking the group with the 'GENL_UNS_ADMIN_PERM' flag. This will prevent non-root users or root without the 'CAP_NET_ADMIN' capability (in the user namespace owning the network namespace) from joining the group. Tested using [1]. Before: # capsh -- -c ./psample_repo # capsh --drop=cap_net_admin -- -c ./psample_repo After: # capsh -- -c ./psample_repo # capsh --drop=cap_net_admin -- -c ./psample_repo Failed to join "packets" multicast group [1] $ cat psample.c #include <stdio.h> #include <netlink/genl/ctrl.h> #include <netlink/genl/genl.h> #include <netlink/socket.h> int join_grp(struct nl_sock *sk, const char *grp_name) { int grp, err; grp = genl_ctrl_resolve_grp(sk, "psample", grp_name); if (grp < 0) { fprintf(stderr, "Failed to resolve \"%s\" multicast group\n", grp_name); return grp; } err = nl_socket_add_memberships(sk, grp, NFNLGRP_NONE); if (err) { fprintf(stderr, "Failed to join \"%s\" multicast group\n", grp_name); return err; } return 0; } int main(int argc, char **argv) { struct nl_sock *sk; int err; sk = nl_socket_alloc(); if (!sk) { fprintf(stderr, "Failed to allocate socket\n"); return -1; } err = genl_connect(sk); if (err) { fprintf(stderr, "Failed to connect socket\n"); return err; } err = join_grp(sk, "config"); if (err) return err; err = join_grp(sk, "packets"); if (err) return err; return 0; } $ gcc -I/usr/include/libnl3 -lnl-3 -lnl-genl-3 -o psample_repo psample.c Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling") Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231206213102.1824398-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-29genetlink: start to validate reserved header bytesJakub Kicinski
We had historically not checked that genlmsghdr.reserved is 0 on input which prevents us from using those precious bytes in the future. One use case would be to extend the cmd field, which is currently just 8 bits wide and 256 is not a lot of commands for some core families. To make sure that new families do the right thing by default put the onus of opting out of validation on existing families. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel) Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-14psample: Add additional metadata attributesIdo Schimmel
Extend psample to report the following attributes when available: * Output traffic class as a 16-bit value * Output traffic class occupancy in bytes as a 64-bit value * End-to-end latency of the packet in nanoseconds resolution * Software timestamp in nanoseconds resolution (always available) * Packet's protocol. Needed for packet dissection in user space (always available) Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-14psample: Encapsulate packet metadata in a structIdo Schimmel
Currently, callers of psample_sample_packet() pass three metadata attributes: Ingress port, egress port and truncated size. Subsequent patches are going to add more attributes (e.g., egress queue occupancy), which also need an indication whether they are valid or not. Encapsulate packet metadata in a struct in order to keep the number of arguments reasonable. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-25net: psample: Fix netlink skb length with tunnel infoChris Mi
Currently, the psample netlink skb is allocated with a size that does not account for the nested 'PSAMPLE_ATTR_TUNNEL' attribute and the padding required for the 64-bit attribute 'PSAMPLE_TUNNEL_KEY_ATTR_ID'. This can result in failure to add attributes to the netlink skb due to insufficient tail room. The following error message is printed to the kernel log: "Could not create psample log message". Fix this by adjusting the allocation size to take into account the nested attribute and the padding. Fixes: d8bed686ab96 ("net: psample: Add tunnel support") CC: Yotam Gigi <yotam.gi@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Chris Mi <cmi@nvidia.com> Link: https://lore.kernel.org/r/20210225075145.184314-1-cmi@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-27net: remove redundant 'depends on NET'Masahiro Yamada
These Kconfig files are included from net/Kconfig, inside the if NET ... endif. Remove 'depends on NET', which we know it is already met. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210125232026.106855-1-masahiroy@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-02genetlink: move to smaller ops wherever possibleJakub Kicinski
Bulk of the genetlink users can use smaller ops, move them. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-23net: psample: fix build error when CONFIG_INET is not enabledRandy Dunlap
Fix psample build error when CONFIG_INET is not set/enabled by bracketing the tunnel code in #ifdef CONFIG_NET / #endif. ../net/psample/psample.c: In function ‘__psample_ip_tun_to_nlattr’: ../net/psample/psample.c:216:25: error: implicit declaration of function ‘ip_tunnel_info_opts’; did you mean ‘ip_tunnel_info_opts_set’? [-Werror=implicit-function-declaration] Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Yotam Gigi <yotam.gi@gmail.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-21net: psample: Add tunnel supportChris Mi
Currently, psample can only send the packet bits after decapsulation. The tunnel information is lost. Add the tunnel support. If the sampled packet has no tunnel info, the behavior is the same as before. If it has, add a nested metadata field named PSAMPLE_ATTR_TUNNEL and include the tunnel subfields if applicable. Increase the metadata length for sampled packet with the tunnel info. If new subfields of tunnel info should be included, update the metadata length accordingly. Signed-off-by: Chris Mi <chrism@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26net: psample: fix skb_over_panicNikolay Aleksandrov
We need to calculate the skb size correctly otherwise we risk triggering skb_over_panic[1]. The issue is that data_len is added to the skb in a nl attribute, but we don't account for its header size (nlattr 4 bytes) and alignment. We account for it when calculating the total size in the > PSAMPLE_MAX_PACKET_SIZE comparison correctly, but not when allocating after that. The fix is simple - use nla_total_size() for data_len when allocating. To reproduce: $ tc qdisc add dev eth1 clsact $ tc filter add dev eth1 egress matchall action sample rate 1 group 1 trunc 129 $ mausezahn eth1 -b bcast -a rand -c 1 -p 129 < skb_over_panic BUG(), tail is 4 bytes past skb->end > [1] Trace: [ 50.459526][ T3480] skbuff: skb_over_panic: text:(____ptrval____) len:196 put:136 head:(____ptrval____) data:(____ptrval____) tail:0xc4 end:0xc0 dev:<NULL> [ 50.474339][ T3480] ------------[ cut here ]------------ [ 50.481132][ T3480] kernel BUG at net/core/skbuff.c:108! [ 50.486059][ T3480] invalid opcode: 0000 [#1] PREEMPT SMP [ 50.489463][ T3480] CPU: 3 PID: 3480 Comm: mausezahn Not tainted 5.4.0-rc7 #108 [ 50.492844][ T3480] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014 [ 50.496551][ T3480] RIP: 0010:skb_panic+0x79/0x7b [ 50.498261][ T3480] Code: bc 00 00 00 41 57 4c 89 e6 48 c7 c7 90 29 9a 83 4c 8b 8b c0 00 00 00 50 8b 83 b8 00 00 00 50 ff b3 c8 00 00 00 e8 ae ef c0 fe <0f> 0b e8 2f df c8 fe 48 8b 55 08 44 89 f6 4c 89 e7 48 c7 c1 a0 22 [ 50.504111][ T3480] RSP: 0018:ffffc90000447a10 EFLAGS: 00010282 [ 50.505835][ T3480] RAX: 0000000000000087 RBX: ffff888039317d00 RCX: 0000000000000000 [ 50.507900][ T3480] RDX: 0000000000000000 RSI: ffffffff812716e1 RDI: 00000000ffffffff [ 50.509820][ T3480] RBP: ffffc90000447a60 R08: 0000000000000001 R09: 0000000000000000 [ 50.511735][ T3480] R10: ffffffff81d4f940 R11: 0000000000000000 R12: ffffffff834a22b0 [ 50.513494][ T3480] R13: ffffffff82c10433 R14: 0000000000000088 R15: ffffffff838a8084 [ 50.515222][ T3480] FS: 00007f3536462700(0000) GS:ffff88803eac0000(0000) knlGS:0000000000000000 [ 50.517135][ T3480] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 50.518583][ T3480] CR2: 0000000000442008 CR3: 000000003b222000 CR4: 00000000000006e0 [ 50.520723][ T3480] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 50.522709][ T3480] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 50.524450][ T3480] Call Trace: [ 50.525214][ T3480] skb_put.cold+0x1b/0x1b [ 50.526171][ T3480] psample_sample_packet+0x1d3/0x340 [ 50.527307][ T3480] tcf_sample_act+0x178/0x250 [ 50.528339][ T3480] tcf_action_exec+0xb1/0x190 [ 50.529354][ T3480] mall_classify+0x67/0x90 [ 50.530332][ T3480] tcf_classify+0x72/0x160 [ 50.531286][ T3480] __dev_queue_xmit+0x3db/0xd50 [ 50.532327][ T3480] dev_queue_xmit+0x18/0x20 [ 50.533299][ T3480] packet_sendmsg+0xee7/0x2090 [ 50.534331][ T3480] sock_sendmsg+0x54/0x70 [ 50.535271][ T3480] __sys_sendto+0x148/0x1f0 [ 50.536252][ T3480] ? tomoyo_file_ioctl+0x23/0x30 [ 50.537334][ T3480] ? ksys_ioctl+0x5e/0xb0 [ 50.540068][ T3480] __x64_sys_sendto+0x2a/0x30 [ 50.542810][ T3480] do_syscall_64+0x73/0x1f0 [ 50.545383][ T3480] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.548477][ T3480] RIP: 0033:0x7f35357d6fb3 [ 50.551020][ T3480] Code: 48 8b 0d 18 90 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 d3 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 eb f6 ff ff 48 89 04 24 [ 50.558547][ T3480] RSP: 002b:00007ffe0c7212c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 50.561870][ T3480] RAX: ffffffffffffffda RBX: 0000000001dac010 RCX: 00007f35357d6fb3 [ 50.565142][ T3480] RDX: 0000000000000082 RSI: 0000000001dac2a2 RDI: 0000000000000003 [ 50.568469][ T3480] RBP: 00007ffe0c7212f0 R08: 00007ffe0c7212d0 R09: 0000000000000014 [ 50.571731][ T3480] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000082 [ 50.574961][ T3480] R13: 0000000001dac2a2 R14: 0000000000000001 R15: 0000000000000003 [ 50.578170][ T3480] Modules linked in: sch_ingress virtio_net [ 50.580976][ T3480] ---[ end trace 61a515626a595af6 ]--- CC: Yotam Gigi <yotamg@mellanox.com> CC: Jiri Pirko <jiri@mellanox.com> CC: Jamal Hadi Salim <jhs@mojatatu.com> CC: Simon Horman <simon.horman@netronome.com> CC: Roopa Prabhu <roopa@cumulusnetworks.com> Fixes: 6ae0a6286171 ("net: Introduce psample, a new genetlink channel for packet sampling") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-16net: sched: take reference to psample group in flow_action infraVlad Buslov
With recent patch set that removed rtnl lock dependency from cls hardware offload API rtnl lock is only taken when reading action data and can be released after action-specific data is parsed into intermediate representation. However, sample action psample group is passed by pointer without obtaining reference to it first, which makes it possible to concurrently overwrite the action and deallocate object pointed by psample_group pointer after rtnl lock is released but before driver finished using the pointer. To prevent such race condition, obtain reference to psample group while it is used by flow_action infra. Extend psample API with function psample_group_take() that increments psample group reference counter. Extend struct tc_action_ops with new get_psample_group() API. Implement the API for action sample using psample_group_take() and already existing psample_group_put() as a destructor. Use it in tc_setup_flow_action() to take reference to psample group pointed to by entry->sample.psample_group and release it in tc_cleanup_flow_action(). Disable bh when taking psample_groups_lock. The lock is now taken while holding action tcf_lock that is used by data path and requires bh to be disabled, so doing the same for psample_groups_lock is necessary to preserve SOFTIRQ-irq-safety. Fixes: 918190f50eb6 ("net: sched: flower: don't take rtnl lock for cls hw offloads API") Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-28net: sched: act_sample: fix psample group handling on overwriteVlad Buslov
Action sample doesn't properly handle psample_group pointer in overwrite case. Following issues need to be fixed: - In tcf_sample_init() function RCU_INIT_POINTER() is used to set s->psample_group, even though we neither setting the pointer to NULL, nor preventing concurrent readers from accessing the pointer in some way. Use rcu_swap_protected() instead to safely reset the pointer. - Old value of s->psample_group is not released or deallocated in any way, which results resource leak. Use psample_group_put() on non-NULL value obtained with rcu_swap_protected(). - The function psample_group_put() that released reference to struct psample_group pointed by rcu-pointer s->psample_group doesn't respect rcu grace period when deallocating it. Extend struct psample_group with rcu head and use kfree_rcu when freeing it. Fixes: 5c5670fae430 ("net/sched: Introduce sample tc action") Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27genetlink: optionally validate strictly/dumpsJohannes Berg
Add options to strictly validate messages and dump messages, sometimes perhaps validating dump messages non-strictly may be required, so add an option for that as well. Since none of this can really be applied to existing commands, set the options everwhere using the following spatch: @@ identifier ops; expression X; @@ struct genl_ops ops[] = { ..., { .cmd = X, + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, ... }, ... }; For new commands one should just not copy the .validate 'opt-out' flags and thus get strict validation. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01MAINTAINERS: Update Yotam's E-mailYotam Gigi
For the time being I will be available in my private mail. Update both the MAINTAINERS file and the individual modules MODULE_AUTHOR directive with the new address. Signed-off-by: Yotam Gigi <yotam.gi@gmail.com> Signed-off-by: Yuval Mintz <yuvalm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16networking: make skb_put & friends return void pointersJohannes Berg
It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions (skb_put, __skb_put and pskb_put) return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_put, __skb_put }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_put, __skb_put }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) which actually doesn't cover pskb_put since there are only three users overall. A handful of stragglers were converted manually, notably a macro in drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many instances in net/bluetooth/hci_sock.c. In the former file, I also had to fix one whitespace problem spatch introduced. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24net: Introduce psample, a new genetlink channel for packet samplingYotam Gigi
Add a general way for kernel modules to sample packets, without being tied to any specific subsystem. This netlink channel can be used by tc, iptables, etc. and allow to standardize packet sampling in the kernel. For every sampled packet, the psample module adds the following metadata fields: PSAMPLE_ATTR_IIFINDEX - the packets input ifindex, if applicable PSAMPLE_ATTR_OIFINDEX - the packet output ifindex, if applicable PSAMPLE_ATTR_ORIGSIZE - the packet's original size, in case it has been truncated during sampling PSAMPLE_ATTR_SAMPLE_GROUP - the packet's sample group, which is set by the user who initiated the sampling. This field allows the user to differentiate between several samplers working simultaneously and filter packets relevant to him PSAMPLE_ATTR_GROUP_SEQ - sequence counter of last sent packet. The sequence is kept for each group PSAMPLE_ATTR_SAMPLE_RATE - the sampling rate used for sampling the packets PSAMPLE_ATTR_DATA - the actual packet bits The sampled packets are sent to the PSAMPLE_NL_MCGRP_SAMPLE multicast group. In addition, add the GET_GROUPS netlink command which allows the user to see the current sample groups, their refcount and sequence number. This command currently supports only netlink dump mode. Signed-off-by: Yotam Gigi <yotamg@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>