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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?4JxMNdGsFF8jSR0MccGTgrD5E0+qv6i639nHVNzt7/CSJivPggbFKzpKCQXq?= =?us-ascii?Q?IT7HJH7YNGCr9/6g5GAsBhW5JQmr39cLvUuLCkJ7NZR9SDP+qqAQUyAhNO5Z?= =?us-ascii?Q?Hp1v9GuctjQTWJg1Ynx43gvQZyY+0jkGbohKW4DPFzVX0VGMhtPiwOZq1D4J?= =?us-ascii?Q?5e3KAeJhJf8HN6eccH7P000xaXJQLNaHg18wEOOlsa84lrKOXb/89L/PHjhL?= =?us-ascii?Q?u+gQOed3yvGZkQoDUx9figLqFqESHR6pVQkD1Kh7YJMbvAFc14W7QKZHkgCR?= =?us-ascii?Q?wA7ZlSQScysJfMCGhEFrEoqZbjTdSDBpyirfJmQPakCVDqZVfWHgSPOcr+QO?= =?us-ascii?Q?2kCt/0NPN/KJbxyFc3vazxuvaz9qcQ7EUAAoaZGjVrrJnNhzLa4NPd06bJNJ?= =?us-ascii?Q?qzK0ZVS8hVBp3XWUTPYymTUF721fYQR6pZhnVPT79POEz34AuU/vDJgas0fQ?= =?us-ascii?Q?8XUjfDnpsePbkxaZ9lb3jTHnwOpAmNYy2BmaZZs5t72O1/FAjE9cv1EzT1NL?= =?us-ascii?Q?hBTHrZInDffNLikzNDG54qfIHrciYMffPH2+SHrTSVXRn/paj01wBP4JiKEV?= =?us-ascii?Q?79taO8ENZGkj59+2J6HvMPCDYBLwSAEzvKe5JYNlptHP03q7M5sHZcYfpJSX?= =?us-ascii?Q?QiiJVnqVtjsBaBSVOGiMoXGLqiMNcxK2MzvpIi6oxpYt128TNuOcqN9My0Wz?= =?us-ascii?Q?FYaUHtGM7JMGxfJWN/ONEbiOTgPWUw4A2Uy6LyWK/HKwymCF9sozJUftDPq4?= =?us-ascii?Q?8XazscQkFWleH3moswcV3oBuPSDmD4qn+zy+JUgwz9F8BlCs/48S47MuORLd?= =?us-ascii?Q?lCPZaWuldPAI0ByJZMhwt2eUW2HRr/aGGmB8i7LNkr0ZaOZPOfv4G7k3/P8J?= =?us-ascii?Q?ub/bYLhOQEDb+IywqrJMLVPBVXFXq8uf7Yx4bQxTABpBc+8MhZalkqDAWdDD?= =?us-ascii?Q?ZbX2hGlIq95wLDk6UwOUPUmg95ZHCDp0diMwc/Qle68QFBS7kFU37RokReMf?= =?us-ascii?Q?iRvQA9m7n/lR+qteb7lzLBBoKs4ZL65e7d7kRRff59r7Qp9rPBZ5FyzU/Vxu?= =?us-ascii?Q?zozjVMgJvDuE82Jqk27FTTz1fzy6jqiifTUxbCrRjjybRPYTHn1abeXTTYQi?= =?us-ascii?Q?ecttwHr62YNHc2DYShB1nhefVILUA7/KeOeEjWLS6dj4ANRB9glE++swOIne?= =?us-ascii?Q?HAT4QerLYeQy3hhkQD+arHkPA4mf7Apwm77i8f0Hh/UifHn8BZKkltTCa9q1?= =?us-ascii?Q?RVFSpB+Vdt2M3BNgexZrpjuOXrX712QxVFw8IIMeODP5Ms9qa3znahgUyWL6?= =?us-ascii?Q?IgbfZr+3u0x0heiBpIxi6b5li42X1weC4Zgp85aLRVyaJC4V5HypBNwPpaX6?= =?us-ascii?Q?N2cqTJn3zHwC+Ry9bTAHzqe7KrnRP4nmIgvaVHBa2KVLFRlMUhgoGgUEspyC?= =?us-ascii?Q?ohXd6+BwTyDqUKFouFqfbWQ1vC0uMo8YlpzegqCQdMjjTVllrYqZ76ZgoUjC?= =?us-ascii?Q?cDfK9ucBYBUWGL5GWaoS6zfZAalwNyQnB/TAS3vm+rfgfiF191NpUqnhDY7I?= =?us-ascii?Q?1D+HgAoBKfzZBnAsPEPAmQTASxi4THqnV64cRpTkVBbHGeFLfDbzRzKT5FSk?= =?us-ascii?Q?A3DEUISMXRfgN5fkLhZMlIXoPOz7xZwKx41I3U5WYTOqL6xIM55c+s556f6B?= =?us-ascii?Q?UioNzaJckv1ih7QIYDamwBX86+n0XNFNSVkCPu3+9qea2a61?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1230cb70-6feb-47d5-4e44-08df072d62f3 X-MS-Exchange-CrossTenant-AuthSource: PH0PR12MB7957.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Aug 2026 06:59:22.7014 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: q8GvR57Zn+01aqib8RWuMMNioduDTfVD51y4Wqqyq8qRGZaInSQBtwl9j3P7xmkPhQF8HcJcJIUu85S2JG6+tA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB7996 On Fri, Aug 28, 2026 at 10:23:44PM +0300, Ido Schimmel wrote: > Add a test for the IPv4 and IPv6 exception caches, covering the > exceptions that are created in response to ICMP errors quoting a UDP > packet. > > The topology consists of a host (h1) that reaches a remote host (h2) > via a router (r1), with a second router (r2) attached to the segment > shared by h1 and r1. UDP packets are injected using a packet socket, so > that an ICMP error quoting them is only matched to a socket when one was > opened separately with the same source port. PMTU errors are provoked by > lowering the MTU of the far end of the path and redirects by pointing > r1's route towards h2 back over the segment it received the packet from. > > The following is tested for both address families and for both PMTU and > redirect exceptions: > > * An error that is not matched to a socket creates an exception that > carries the new MTU or gateway. > * An error that is matched to a socket creates the same exception. > > The PMTU tests further verify that a lower PMTU replaces the one stored > in the exception whereas a higher one does not, and that a socket which > disabled PMTU discovery using IP{,V6}_PMTUDISC_OMIT gets the same > exception as the other cases. > > Without "ipv4: udp: Create exceptions before socket matching" and "ipv6: > udp: Create exceptions before socket matching", the tests that do not > open a socket fail: Both of the comments from Sashiko are nits. The test passes when it should and fails otherwise, so it's doing its job. " This isn't a bug, but a question about what the "with a socket" cases assert. pmtu_socket(), pmtu_omit() and redirect_socket() only look at the route exception, and with the two accompanying kernel changes that exception is created before the socket lookup: " It asserts that an exception is created regardless of whether the ICMP error matched a socket or not. " Is the ICMP input counter a strong enough barrier for this check? " Yes.