kernel/linux.git/include/net/ip6_tunnel.h, branch v6.6.131

ip_gre, ip6_gre: Fix race condition on o_seqno in collect_md mode

2022-04-25T10:40:45+00:00

As pointed out by Jakub Kicinski, currently using TUNNEL_SEQ in collect_md mode is racy for [IP6]GRE[TAP] devices. Consider the following sequence of events: 1. An [IP6]GRE[TAP] device is created in collect_md mode using "ip link add ... external". "ip" ignores "[o]seq" if "external" is specified, so TUNNEL_SEQ is off, and the device is marked as NETIF_F_LLTX (i.e. it uses lockless TX); 2. Someone sets TUNNEL_SEQ on outgoing skb's, using e.g. bpf_skb_set_tunnel_key() in an eBPF program attached to this device; 3. gre_fb_xmit() or __gre6_xmit() processes these skb's: gre_build_header(skb, tun_hlen, flags, protocol, tunnel_id_to_key32(tun_info->key.tun_id), (flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++) : 0); ^^^^^^^^^^^^^^^^^ Since we are not using the TX lock (&txq->_xmit_lock), multiple CPUs may try to do this tunnel->o_seqno++ in parallel, which is racy. Fix it by making o_seqno atomic_t. As mentioned by Eric Dumazet in commit b790e01aee74 ("ip_gre: lockless xmit"), making o_seqno atomic_t increases "chance for packets being out of order at receiver" when NETIF_F_LLTX is on. Maybe a better fix would be: 1. Do not ignore "oseq" in external mode. Users MUST specify "oseq" if they want the kernel to allow sequencing of outgoing packets; 2. Reject all outgoing TUNNEL_SEQ packets if the device was not created with "oseq". Unfortunately, that would break userspace. We could now make [IP6]GRE[TAP] devices always NETIF_F_LLTX, but let us do it in separate patches to keep this fix minimal. Suggested-by: Jakub Kicinski Fixes: 77a5196a804e ("gre: add sequence number for collect md mode.") Signed-off-by: Peilin Ye Acked-by: William Tu Signed-off-by: David S. Miller

ipv6: add net device refcount tracker to struct ip6_tnl

2021-12-07T00:05:11+00:00

Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL

2019-06-19T00:48:45+00:00

A similar fix to Patch "ip_tunnel: allow not to count pkts on tstats by setting skb's dev to NULL" is also needed by ip6_tunnel. Signed-off-by: Xin Long Signed-off-by: David S. Miller

udp: Support for error handlers of tunnels with arbitrary destination port

2018-11-09T01:13:08+00:00

ICMP error handling is currently not possible for UDP tunnels not employing a receiving socket with local destination port matching the remote one, because we have no way to look them up. Add an err_handler tunnel encapsulation operation that can be exported by tunnels in order to pass the error to the protocol implementing the encapsulation. We can't easily use a lookup function as we did for VXLAN and GENEVE, as protocol error handlers, which would be in turn called by implementations of this new operation, handle the errors themselves, together with the tunnel lookup. Without a socket, we can't be sure which encapsulation error handler is the appropriate one: encapsulation handlers (the ones for FoU and GUE introduced in the next patch, e.g.) will need to check the new error codes returned by protocol handlers to figure out if errors match the given encapsulation, and, in turn, report this error back, so that we can try all of them in __udp{4,6}_lib_err_encap_no_sk() until we have a match. v2: - Name all arguments in err_handler prototypes (David Miller) Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller

ip6_gre: add erspan v2 support

2017-12-15T17:34:00+00:00

Similar to support for ipv4 erspan, this patch adds erspan v2 to ip6erspan tunnel. Signed-off-by: William Tu Signed-off-by: David S. Miller

ip6_gre: Add ERSPAN native tunnel support

2017-12-01T20:33:27+00:00

The patch adds support for ERSPAN tunnel over ipv6. Signed-off-by: William Tu Signed-off-by: David S. Miller

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

ip6_tunnel: Allow policy-based routing through tunnels

2017-04-21T17:21:30+00:00

This feature allows the administrator to set an fwmark for packets traversing a tunnel. This allows the use of independent routing tables for tunneled packets without the use of iptables. Signed-off-by: Craig Gallek Signed-off-by: David S. Miller

ip6_tunnel: Clear IP6CB in ip6tunnel_xmit()

2016-11-02T19:18:36+00:00

skb->cb may contain data from previous layers. In the observed scenario, the garbage data were misinterpreted as IP6CB(skb)->frag_max_size, so that small packets sent through the tunnel are mistakenly fragmented. This patch unconditionally clears the control buffer in ip6tunnel_xmit(), which affects ip6_tunnel, ip6_udp_tunnel and ip6_gre. Currently none of these tunnels set IP6CB(skb)->flags, otherwise it needs to be done earlier. Cc: stable@vger.kernel.org Signed-off-by: Eli Cooper Signed-off-by: David S. Miller

ip6_tunnel: add collect_md mode to IPv6 tunnels

2016-09-17T14:13:07+00:00

Similar to gre, vxlan, geneve tunnels allow IPIP6 and IP6IP6 tunnels to operate in 'collect metadata' mode. Unlike ipv4 code here it's possible to reuse ip6_tnl_xmit() function for both collect_md and traditional tunnels. bpf_skb_[gs]et_tunnel_key() helpers and ovs (in the future) are the users. Signed-off-by: Alexei Starovoitov Acked-by: Thomas Graf Acked-by: Daniel Borkmann Signed-off-by: David S. Miller