4e35c1cb94
It is possible that two concurrent packets originating from the same socket of a connection-less protocol (e.g. UDP) can end up having different IP_CT_DIR_REPLY tuples which results in one of the packets being dropped. To illustrate this, consider the following simplified scenario: 1. Packet A and B are sent at the same time from two different threads by same UDP socket. No matching conntrack entry exists yet. Both packets cause allocation of a new conntrack entry. 2. get_unique_tuple gets called for A. No clashing entry found. conntrack entry for A is added to main conntrack table. 3. get_unique_tuple is called for B and will find that the reply tuple of B is already taken by A. It will allocate a new UDP source port for B to resolve the clash. 4. conntrack entry for B cannot be added to main conntrack table because its ORIGINAL direction is clashing with A and the REPLY directions of A and B are not the same anymore due to UDP source port reallocation done in step 3. This patch modifies nf_conntrack_tuple_taken so it doesn't consider colliding reply tuples if the IP_CT_DIR_ORIGINAL tuples are equal. [ Florian: simplify patch to not use .allow_clash setting and always ignore identical flows ] Signed-off-by: Martynas Pumputis <martynas@weave.works> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.