Mercurial > hg > nginx
view src/mail/ngx_mail_imap_handler.c @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | b2915d99ee8d |
children | ab6257dac2a8 |
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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> #include <ngx_mail_imap_module.h> static ngx_int_t ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c); static u_char imap_greeting[] = "* OK IMAP4 ready" CRLF; static u_char imap_star[] = "* "; static u_char imap_ok[] = "OK completed" CRLF; static u_char imap_next[] = "+ OK" CRLF; static u_char imap_plain_next[] = "+ " CRLF; static u_char imap_username[] = "+ VXNlcm5hbWU6" CRLF; static u_char imap_password[] = "+ UGFzc3dvcmQ6" CRLF; static u_char imap_bye[] = "* BYE" CRLF; static u_char imap_invalid_command[] = "BAD invalid command" CRLF; void ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_mail_core_srv_conf_t *cscf; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_str_set(&s->out, imap_greeting); c->read->handler = ngx_mail_imap_init_protocol; ngx_add_timer(c->read, cscf->timeout); if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_close_connection(c); } ngx_mail_send(c->write); } void ngx_mail_imap_init_protocol(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_imap_srv_conf_t *iscf; c = rev->data; c->log->action = "in auth state"; if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; ngx_mail_close_connection(c); return; } s = c->data; if (s->buffer == NULL) { if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t)) == NGX_ERROR) { ngx_mail_session_internal_server_error(s); return; } iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module); s->buffer = ngx_create_temp_buf(c->pool, iscf->client_buffer_size); if (s->buffer == NULL) { ngx_mail_session_internal_server_error(s); return; } } s->mail_state = ngx_imap_start; c->read->handler = ngx_mail_imap_auth_state; ngx_mail_imap_auth_state(rev); } void ngx_mail_imap_auth_state(ngx_event_t *rev) { u_char *p, *dst, *src, *end; ngx_str_t *arg; ngx_int_t rc; ngx_uint_t tag, i; ngx_connection_t *c; ngx_mail_session_t *s; c = rev->data; s = c->data; ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth state"); if (rev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; ngx_mail_close_connection(c); return; } if (s->out.len) { ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap send handler busy"); s->blocked = 1; return; } s->blocked = 0; rc = ngx_mail_read_command(s, c); if (rc == NGX_AGAIN || rc == NGX_ERROR) { return; } tag = 1; s->text.len = 0; ngx_str_set(&s->out, imap_ok); if (rc == NGX_OK) { ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i", s->command); if (s->backslash) { arg = s->args.elts; for (i = 0; i < s->args.nelts; i++) { dst = arg[i].data; end = dst + arg[i].len; for (src = dst; src < end; dst++) { *dst = *src; if (*src++ == '\\') { *dst = *src++; } } arg[i].len = dst - arg[i].data; } s->backslash = 0; } switch (s->mail_state) { case ngx_imap_start: switch (s->command) { case NGX_IMAP_LOGIN: rc = ngx_mail_imap_login(s, c); break; case NGX_IMAP_AUTHENTICATE: rc = ngx_mail_imap_authenticate(s, c); tag = (rc != NGX_OK); break; case NGX_IMAP_CAPABILITY: rc = ngx_mail_imap_capability(s, c); break; case NGX_IMAP_LOGOUT: s->quit = 1; ngx_str_set(&s->text, imap_bye); break; case NGX_IMAP_NOOP: break; case NGX_IMAP_STARTTLS: rc = ngx_mail_imap_starttls(s, c); break; default: rc = NGX_MAIL_PARSE_INVALID_COMMAND; break; } break; case ngx_imap_auth_login_username: rc = ngx_mail_auth_login_username(s, c, 0); tag = 0; ngx_str_set(&s->out, imap_password); s->mail_state = ngx_imap_auth_login_password; break; case ngx_imap_auth_login_password: rc = ngx_mail_auth_login_password(s, c); break; case ngx_imap_auth_plain: rc = ngx_mail_auth_plain(s, c, 0); break; case ngx_imap_auth_cram_md5: rc = ngx_mail_auth_cram_md5(s, c); break; case ngx_imap_auth_external: rc = ngx_mail_auth_external(s, c, 0); break; } } else if (rc == NGX_IMAP_NEXT) { tag = 0; ngx_str_set(&s->out, imap_next); } switch (rc) { case NGX_DONE: ngx_mail_auth(s, c); return; case NGX_ERROR: ngx_mail_session_internal_server_error(s); return; case NGX_MAIL_PARSE_INVALID_COMMAND: s->state = 0; ngx_str_set(&s->out, imap_invalid_command); s->mail_state = ngx_imap_start; break; } if (tag) { if (s->tag.len == 0) { ngx_str_set(&s->tag, imap_star); } if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) { s->tagged_line.len = s->tag.len + s->text.len + s->out.len; s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len); if (s->tagged_line.data == NULL) { ngx_mail_close_connection(c); return; } } p = s->tagged_line.data; if (s->text.len) { p = ngx_cpymem(p, s->text.data, s->text.len); } p = ngx_cpymem(p, s->tag.data, s->tag.len); ngx_memcpy(p, s->out.data, s->out.len); s->out.len = s->text.len + s->tag.len + s->out.len; s->out.data = s->tagged_line.data; } if (rc != NGX_IMAP_NEXT) { s->args.nelts = 0; if (s->state) { /* preserve tag */ s->arg_start = s->buffer->start + s->tag.len; s->buffer->pos = s->arg_start; s->buffer->last = s->arg_start; } else { s->buffer->pos = s->buffer->start; s->buffer->last = s->buffer->start; s->tag.len = 0; } } ngx_mail_send(c->write); } static ngx_int_t ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_str_t *arg; #if (NGX_MAIL_SSL) if (ngx_mail_starttls_only(s, c)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } #endif arg = s->args.elts; if (s->args.nelts != 2 || arg[0].len == 0) { return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = arg[0].len; s->login.data = ngx_pnalloc(c->pool, s->login.len); if (s->login.data == NULL) { return NGX_ERROR; } ngx_memcpy(s->login.data, arg[0].data, s->login.len); s->passwd.len = arg[1].len; s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len); if (s->passwd.data == NULL) { return NGX_ERROR; } ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len); #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap login:\"%V\" passwd:\"%V\"", &s->login, &s->passwd); #else ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap login:\"%V\"", &s->login); #endif return NGX_DONE; } static ngx_int_t ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_int_t rc; ngx_mail_core_srv_conf_t *cscf; ngx_mail_imap_srv_conf_t *iscf; #if (NGX_MAIL_SSL) if (ngx_mail_starttls_only(s, c)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } #endif iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module); rc = ngx_mail_auth_parse(s, c); switch (rc) { case NGX_MAIL_AUTH_LOGIN: ngx_str_set(&s->out, imap_username); s->mail_state = ngx_imap_auth_login_username; return NGX_OK; case NGX_MAIL_AUTH_LOGIN_USERNAME: ngx_str_set(&s->out, imap_password); s->mail_state = ngx_imap_auth_login_password; return ngx_mail_auth_login_username(s, c, 1); case NGX_MAIL_AUTH_PLAIN: ngx_str_set(&s->out, imap_plain_next); s->mail_state = ngx_imap_auth_plain; return NGX_OK; case NGX_MAIL_AUTH_CRAM_MD5: if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } if (s->salt.data == NULL) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); if (ngx_mail_salt(s, c, cscf) != NGX_OK) { return NGX_ERROR; } } if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) { s->mail_state = ngx_imap_auth_cram_md5; return NGX_OK; } return NGX_ERROR; case NGX_MAIL_AUTH_EXTERNAL: if (!(iscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_str_set(&s->out, imap_username); s->mail_state = ngx_imap_auth_external; return NGX_OK; } return rc; } static ngx_int_t ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_mail_imap_srv_conf_t *iscf; iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module); #if (NGX_MAIL_SSL) if (c->ssl == NULL) { ngx_mail_ssl_conf_t *sslcf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) { s->text = iscf->starttls_capability; return NGX_OK; } if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) { s->text = iscf->starttls_only_capability; return NGX_OK; } } #endif s->text = iscf->capability; return NGX_OK; } static ngx_int_t ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c) { #if (NGX_MAIL_SSL) ngx_mail_ssl_conf_t *sslcf; if (c->ssl == NULL) { sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->starttls) { c->read->handler = ngx_mail_starttls_handler; return NGX_OK; } } #endif return NGX_MAIL_PARSE_INVALID_COMMAND; }