Mercurial > hg > nginx
view src/mail/ngx_mail_pop3_module.h @ 8913:40445fc7c403 quic
QUIC: fixed migration during NAT rebinding.
The RFC 9000 allows a packet from known CID arrive from unknown path:
These requirements regarding connection ID reuse apply only to the
sending of packets, as unintentional changes in path without a change
in connection ID are possible. For example, after a period of
network inactivity, NAT rebinding might cause packets to be sent on a
new path when the client resumes sending.
Before the patch, such packets were rejected with an error in the
ngx_quic_check_migration() function. Removing the check makes the
separate function excessive - remaining checks are early migration
check and "disable_active_migration" check. The latter is a transport
parameter sent to client and it should not be used by server.
The server should send "disable_active_migration" "if the endpoint does
not support active connection migration" (18.2). The support status depends
on nginx configuration: to have migration working with multiple workers,
you need bpf helper, available on recent Linux systems. The patch does
not set "disable_active_migration" automatically and leaves it for the
administrator. By default, active migration is enabled.
RFC 900 says that it is ok to migrate if the peer violates
"disable_active_migration" flag requirements:
If the peer violates this requirement,
the endpoint MUST either drop the incoming packets on that path without
generating a Stateless Reset
OR
proceed with path validation and allow the peer to migrate. Generating a
Stateless Reset or closing the connection would allow third parties in the
network to cause connections to close by spoofing or otherwise manipulating
observed traffic.
So, nginx adheres to the second option and proceeds to path validation.
Note:
The ngtcp2 may be used for testing both active migration and NAT rebinding:
ngtcp2/client --change-local-addr=200ms --delay-stream=500ms <ip> <port> <url>
ngtcp2/client --change-local-addr=200ms --delay-stream=500ms --nat-rebinding \
<ip> <port> <url>
author | Vladimir Homutov <vl@nginx.com> |
---|---|
date | Mon, 29 Nov 2021 11:51:14 +0300 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_MAIL_POP3_MODULE_H_INCLUDED_ #define _NGX_MAIL_POP3_MODULE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_mail.h> typedef struct { ngx_str_t capability; ngx_str_t starttls_capability; ngx_str_t starttls_only_capability; ngx_str_t auth_capability; ngx_uint_t auth_methods; ngx_array_t capabilities; } ngx_mail_pop3_srv_conf_t; void ngx_mail_pop3_init_session(ngx_mail_session_t *s, ngx_connection_t *c); void ngx_mail_pop3_init_protocol(ngx_event_t *rev); void ngx_mail_pop3_auth_state(ngx_event_t *rev); ngx_int_t ngx_mail_pop3_parse_command(ngx_mail_session_t *s); extern ngx_module_t ngx_mail_pop3_module; #endif /* _NGX_MAIL_POP3_MODULE_H_INCLUDED_ */