Mercurial > hg > nginx
view src/mail/ngx_mail.c @ 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 | 12ea1de7d87c |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> static char *ngx_mail_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_int_t ngx_mail_add_ports(ngx_conf_t *cf, ngx_array_t *ports, ngx_mail_listen_t *listen); static char *ngx_mail_optimize_servers(ngx_conf_t *cf, ngx_array_t *ports); static ngx_int_t ngx_mail_add_addrs(ngx_conf_t *cf, ngx_mail_port_t *mport, ngx_mail_conf_addr_t *addr); #if (NGX_HAVE_INET6) static ngx_int_t ngx_mail_add_addrs6(ngx_conf_t *cf, ngx_mail_port_t *mport, ngx_mail_conf_addr_t *addr); #endif static ngx_int_t ngx_mail_cmp_conf_addrs(const void *one, const void *two); ngx_uint_t ngx_mail_max_module; static ngx_command_t ngx_mail_commands[] = { { ngx_string("mail"), NGX_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_NOARGS, ngx_mail_block, 0, 0, NULL }, ngx_null_command }; static ngx_core_module_t ngx_mail_module_ctx = { ngx_string("mail"), NULL, NULL }; ngx_module_t ngx_mail_module = { NGX_MODULE_V1, &ngx_mail_module_ctx, /* module context */ ngx_mail_commands, /* module directives */ NGX_CORE_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static char * ngx_mail_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { char *rv; ngx_uint_t i, m, mi, s; ngx_conf_t pcf; ngx_array_t ports; ngx_mail_listen_t *listen; ngx_mail_module_t *module; ngx_mail_conf_ctx_t *ctx; ngx_mail_core_srv_conf_t **cscfp; ngx_mail_core_main_conf_t *cmcf; if (*(ngx_mail_conf_ctx_t **) conf) { return "is duplicate"; } /* the main mail context */ ctx = ngx_pcalloc(cf->pool, sizeof(ngx_mail_conf_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } *(ngx_mail_conf_ctx_t **) conf = ctx; /* count the number of the mail modules and set up their indices */ ngx_mail_max_module = ngx_count_modules(cf->cycle, NGX_MAIL_MODULE); /* the mail main_conf context, it is the same in the all mail contexts */ ctx->main_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_mail_max_module); if (ctx->main_conf == NULL) { return NGX_CONF_ERROR; } /* * the mail null srv_conf context, it is used to merge * the server{}s' srv_conf's */ ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_mail_max_module); if (ctx->srv_conf == NULL) { return NGX_CONF_ERROR; } /* * create the main_conf's and the null srv_conf's of the all mail modules */ for (m = 0; cf->cycle->modules[m]; m++) { if (cf->cycle->modules[m]->type != NGX_MAIL_MODULE) { continue; } module = cf->cycle->modules[m]->ctx; mi = cf->cycle->modules[m]->ctx_index; if (module->create_main_conf) { ctx->main_conf[mi] = module->create_main_conf(cf); if (ctx->main_conf[mi] == NULL) { return NGX_CONF_ERROR; } } if (module->create_srv_conf) { ctx->srv_conf[mi] = module->create_srv_conf(cf); if (ctx->srv_conf[mi] == NULL) { return NGX_CONF_ERROR; } } } /* parse inside the mail{} block */ pcf = *cf; cf->ctx = ctx; cf->module_type = NGX_MAIL_MODULE; cf->cmd_type = NGX_MAIL_MAIN_CONF; rv = ngx_conf_parse(cf, NULL); if (rv != NGX_CONF_OK) { *cf = pcf; return rv; } /* init mail{} main_conf's, merge the server{}s' srv_conf's */ cmcf = ctx->main_conf[ngx_mail_core_module.ctx_index]; cscfp = cmcf->servers.elts; for (m = 0; cf->cycle->modules[m]; m++) { if (cf->cycle->modules[m]->type != NGX_MAIL_MODULE) { continue; } module = cf->cycle->modules[m]->ctx; mi = cf->cycle->modules[m]->ctx_index; /* init mail{} main_conf's */ cf->ctx = ctx; if (module->init_main_conf) { rv = module->init_main_conf(cf, ctx->main_conf[mi]); if (rv != NGX_CONF_OK) { *cf = pcf; return rv; } } for (s = 0; s < cmcf->servers.nelts; s++) { /* merge the server{}s' srv_conf's */ cf->ctx = cscfp[s]->ctx; if (module->merge_srv_conf) { rv = module->merge_srv_conf(cf, ctx->srv_conf[mi], cscfp[s]->ctx->srv_conf[mi]); if (rv != NGX_CONF_OK) { *cf = pcf; return rv; } } } } *cf = pcf; if (ngx_array_init(&ports, cf->temp_pool, 4, sizeof(ngx_mail_conf_port_t)) != NGX_OK) { return NGX_CONF_ERROR; } listen = cmcf->listen.elts; for (i = 0; i < cmcf->listen.nelts; i++) { if (ngx_mail_add_ports(cf, &ports, &listen[i]) != NGX_OK) { return NGX_CONF_ERROR; } } return ngx_mail_optimize_servers(cf, &ports); } static ngx_int_t ngx_mail_add_ports(ngx_conf_t *cf, ngx_array_t *ports, ngx_mail_listen_t *listen) { in_port_t p; ngx_uint_t i; struct sockaddr *sa; ngx_mail_conf_port_t *port; ngx_mail_conf_addr_t *addr; sa = listen->sockaddr; p = ngx_inet_get_port(sa); port = ports->elts; for (i = 0; i < ports->nelts; i++) { if (p == port[i].port && sa->sa_family == port[i].family) { /* a port is already in the port list */ port = &port[i]; goto found; } } /* add a port to the port list */ port = ngx_array_push(ports); if (port == NULL) { return NGX_ERROR; } port->family = sa->sa_family; port->port = p; if (ngx_array_init(&port->addrs, cf->temp_pool, 2, sizeof(ngx_mail_conf_addr_t)) != NGX_OK) { return NGX_ERROR; } found: addr = ngx_array_push(&port->addrs); if (addr == NULL) { return NGX_ERROR; } addr->opt = *listen; return NGX_OK; } static char * ngx_mail_optimize_servers(ngx_conf_t *cf, ngx_array_t *ports) { ngx_uint_t i, p, last, bind_wildcard; ngx_listening_t *ls; ngx_mail_port_t *mport; ngx_mail_conf_port_t *port; ngx_mail_conf_addr_t *addr; ngx_mail_core_srv_conf_t *cscf; port = ports->elts; for (p = 0; p < ports->nelts; p++) { ngx_sort(port[p].addrs.elts, (size_t) port[p].addrs.nelts, sizeof(ngx_mail_conf_addr_t), ngx_mail_cmp_conf_addrs); addr = port[p].addrs.elts; last = port[p].addrs.nelts; /* * if there is the binding to the "*:port" then we need to bind() * to the "*:port" only and ignore the other bindings */ if (addr[last - 1].opt.wildcard) { addr[last - 1].opt.bind = 1; bind_wildcard = 1; } else { bind_wildcard = 0; } i = 0; while (i < last) { if (bind_wildcard && !addr[i].opt.bind) { i++; continue; } ls = ngx_create_listening(cf, addr[i].opt.sockaddr, addr[i].opt.socklen); if (ls == NULL) { return NGX_CONF_ERROR; } ls->addr_ntop = 1; ls->handler = ngx_mail_init_connection; ls->pool_size = 256; cscf = addr->opt.ctx->srv_conf[ngx_mail_core_module.ctx_index]; ls->logp = cscf->error_log; ls->log.data = &ls->addr_text; ls->log.handler = ngx_accept_log_error; ls->backlog = addr[i].opt.backlog; ls->rcvbuf = addr[i].opt.rcvbuf; ls->sndbuf = addr[i].opt.sndbuf; ls->keepalive = addr[i].opt.so_keepalive; #if (NGX_HAVE_KEEPALIVE_TUNABLE) ls->keepidle = addr[i].opt.tcp_keepidle; ls->keepintvl = addr[i].opt.tcp_keepintvl; ls->keepcnt = addr[i].opt.tcp_keepcnt; #endif #if (NGX_HAVE_INET6) ls->ipv6only = addr[i].opt.ipv6only; #endif mport = ngx_palloc(cf->pool, sizeof(ngx_mail_port_t)); if (mport == NULL) { return NGX_CONF_ERROR; } ls->servers = mport; mport->naddrs = i + 1; switch (ls->sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: if (ngx_mail_add_addrs6(cf, mport, addr) != NGX_OK) { return NGX_CONF_ERROR; } break; #endif default: /* AF_INET */ if (ngx_mail_add_addrs(cf, mport, addr) != NGX_OK) { return NGX_CONF_ERROR; } break; } addr++; last--; } } return NGX_CONF_OK; } static ngx_int_t ngx_mail_add_addrs(ngx_conf_t *cf, ngx_mail_port_t *mport, ngx_mail_conf_addr_t *addr) { ngx_uint_t i; ngx_mail_in_addr_t *addrs; struct sockaddr_in *sin; mport->addrs = ngx_pcalloc(cf->pool, mport->naddrs * sizeof(ngx_mail_in_addr_t)); if (mport->addrs == NULL) { return NGX_ERROR; } addrs = mport->addrs; for (i = 0; i < mport->naddrs; i++) { sin = (struct sockaddr_in *) addr[i].opt.sockaddr; addrs[i].addr = sin->sin_addr.s_addr; addrs[i].conf.ctx = addr[i].opt.ctx; #if (NGX_MAIL_SSL) addrs[i].conf.ssl = addr[i].opt.ssl; #endif addrs[i].conf.proxy_protocol = addr[i].opt.proxy_protocol; addrs[i].conf.addr_text = addr[i].opt.addr_text; } return NGX_OK; } #if (NGX_HAVE_INET6) static ngx_int_t ngx_mail_add_addrs6(ngx_conf_t *cf, ngx_mail_port_t *mport, ngx_mail_conf_addr_t *addr) { ngx_uint_t i; ngx_mail_in6_addr_t *addrs6; struct sockaddr_in6 *sin6; mport->addrs = ngx_pcalloc(cf->pool, mport->naddrs * sizeof(ngx_mail_in6_addr_t)); if (mport->addrs == NULL) { return NGX_ERROR; } addrs6 = mport->addrs; for (i = 0; i < mport->naddrs; i++) { sin6 = (struct sockaddr_in6 *) addr[i].opt.sockaddr; addrs6[i].addr6 = sin6->sin6_addr; addrs6[i].conf.ctx = addr[i].opt.ctx; #if (NGX_MAIL_SSL) addrs6[i].conf.ssl = addr[i].opt.ssl; #endif addrs6[i].conf.proxy_protocol = addr[i].opt.proxy_protocol; addrs6[i].conf.addr_text = addr[i].opt.addr_text; } return NGX_OK; } #endif static ngx_int_t ngx_mail_cmp_conf_addrs(const void *one, const void *two) { ngx_mail_conf_addr_t *first, *second; first = (ngx_mail_conf_addr_t *) one; second = (ngx_mail_conf_addr_t *) two; if (first->opt.wildcard) { /* a wildcard must be the last resort, shift it to the end */ return 1; } if (second->opt.wildcard) { /* a wildcard must be the last resort, shift it to the end */ return -1; } if (first->opt.bind && !second->opt.bind) { /* shift explicit bind()ed addresses to the start */ return -1; } if (!first->opt.bind && second->opt.bind) { /* shift explicit bind()ed addresses to the start */ return 1; } /* do not sort by default */ return 0; }