Mercurial > hg > nginx-quic
view src/mail/ngx_mail_pop3_handler.c @ 8551:c35b255d80dc quic
HTTP/3: close connection on keepalive_requests * 2.
After receiving GOAWAY, client is not supposed to create new streams. However,
until client reads this frame, we allow it to create new streams, which are
gracefully rejected. To prevent client from abusing this algorithm, a new
limit is introduced. Upon reaching keepalive_requests * 2, server now closes
the entire QUIC connection claiming excessive load.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 29 Jul 2021 16:01:37 +0300 |
parents | 815c63581be4 |
children |
line wrap: on
line source
/* * 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_pop3_module.h> static ngx_int_t ngx_mail_pop3_user(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c, ngx_int_t stls); static ngx_int_t ngx_mail_pop3_stls(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c); static ngx_int_t ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c); static u_char pop3_greeting[] = "+OK POP3 ready" CRLF; static u_char pop3_ok[] = "+OK" CRLF; static u_char pop3_next[] = "+ " CRLF; static u_char pop3_username[] = "+ VXNlcm5hbWU6" CRLF; static u_char pop3_password[] = "+ UGFzc3dvcmQ6" CRLF; static u_char pop3_invalid_command[] = "-ERR invalid command" CRLF; void ngx_mail_pop3_init_session(ngx_mail_session_t *s, ngx_connection_t *c) { u_char *p; ngx_mail_core_srv_conf_t *cscf; ngx_mail_pop3_srv_conf_t *pscf; pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); if (pscf->auth_methods & (NGX_MAIL_AUTH_APOP_ENABLED|NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) { if (ngx_mail_salt(s, c, cscf) != NGX_OK) { ngx_mail_session_internal_server_error(s); return; } s->out.data = ngx_pnalloc(c->pool, sizeof(pop3_greeting) + s->salt.len); if (s->out.data == NULL) { ngx_mail_session_internal_server_error(s); return; } p = ngx_cpymem(s->out.data, pop3_greeting, sizeof(pop3_greeting) - 3); *p++ = ' '; p = ngx_cpymem(p, s->salt.data, s->salt.len); s->out.len = p - s->out.data; } else { ngx_str_set(&s->out, pop3_greeting); } c->read->handler = ngx_mail_pop3_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_pop3_init_protocol(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; 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; } s->buffer = ngx_create_temp_buf(c->pool, 128); if (s->buffer == NULL) { ngx_mail_session_internal_server_error(s); return; } } s->mail_state = ngx_pop3_start; c->read->handler = ngx_mail_pop3_auth_state; ngx_mail_pop3_auth_state(rev); } void ngx_mail_pop3_auth_state(ngx_event_t *rev) { ngx_int_t rc; 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, "pop3 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, "pop3 send handler busy"); s->blocked = 1; if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } return; } s->blocked = 0; rc = ngx_mail_read_command(s, c); if (rc == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_session_internal_server_error(s); return; } return; } if (rc == NGX_ERROR) { return; } ngx_str_set(&s->out, pop3_ok); if (rc == NGX_OK) { switch (s->mail_state) { case ngx_pop3_start: switch (s->command) { case NGX_POP3_USER: rc = ngx_mail_pop3_user(s, c); break; case NGX_POP3_CAPA: rc = ngx_mail_pop3_capa(s, c, 1); break; case NGX_POP3_APOP: rc = ngx_mail_pop3_apop(s, c); break; case NGX_POP3_AUTH: rc = ngx_mail_pop3_auth(s, c); break; case NGX_POP3_QUIT: s->quit = 1; break; case NGX_POP3_NOOP: break; case NGX_POP3_STLS: rc = ngx_mail_pop3_stls(s, c); break; default: rc = NGX_MAIL_PARSE_INVALID_COMMAND; break; } break; case ngx_pop3_user: switch (s->command) { case NGX_POP3_PASS: rc = ngx_mail_pop3_pass(s, c); break; case NGX_POP3_CAPA: rc = ngx_mail_pop3_capa(s, c, 0); break; case NGX_POP3_QUIT: s->quit = 1; break; case NGX_POP3_NOOP: break; default: rc = NGX_MAIL_PARSE_INVALID_COMMAND; break; } break; /* suppress warnings */ case ngx_pop3_passwd: break; case ngx_pop3_auth_login_username: rc = ngx_mail_auth_login_username(s, c, 0); ngx_str_set(&s->out, pop3_password); s->mail_state = ngx_pop3_auth_login_password; break; case ngx_pop3_auth_login_password: rc = ngx_mail_auth_login_password(s, c); break; case ngx_pop3_auth_plain: rc = ngx_mail_auth_plain(s, c, 0); break; case ngx_pop3_auth_cram_md5: rc = ngx_mail_auth_cram_md5(s, c); break; case ngx_pop3_auth_external: rc = ngx_mail_auth_external(s, c, 0); break; } } if (s->buffer->pos < s->buffer->last) { s->blocked = 1; } 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->mail_state = ngx_pop3_start; s->state = 0; ngx_str_set(&s->out, pop3_invalid_command); /* fall through */ case NGX_OK: s->args.nelts = 0; if (s->buffer->pos == s->buffer->last) { s->buffer->pos = s->buffer->start; s->buffer->last = s->buffer->start; } if (s->state) { s->arg_start = s->buffer->pos; } if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_session_internal_server_error(s); return; } ngx_mail_send(c->write); } } static ngx_int_t ngx_mail_pop3_user(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 if (s->args.nelts != 1) { return NGX_MAIL_PARSE_INVALID_COMMAND; } arg = s->args.elts; 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); ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 login: \"%V\"", &s->login); s->mail_state = ngx_pop3_user; return NGX_OK; } static ngx_int_t ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_str_t *arg; if (s->args.nelts != 1) { return NGX_MAIL_PARSE_INVALID_COMMAND; } arg = s->args.elts; s->passwd.len = arg[0].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[0].data, s->passwd.len); #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 passwd: \"%V\"", &s->passwd); #endif return NGX_DONE; } static ngx_int_t ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c, ngx_int_t stls) { ngx_mail_pop3_srv_conf_t *pscf; pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module); #if (NGX_MAIL_SSL) if (stls && 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->out = pscf->starttls_capability; return NGX_OK; } if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) { s->out = pscf->starttls_only_capability; return NGX_OK; } } #endif s->out = pscf->capability; return NGX_OK; } static ngx_int_t ngx_mail_pop3_stls(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) { s->buffer->pos = s->buffer->start; s->buffer->last = s->buffer->start; c->read->handler = ngx_mail_starttls_handler; return NGX_OK; } } #endif return NGX_MAIL_PARSE_INVALID_COMMAND; } static ngx_int_t ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_str_t *arg; ngx_mail_pop3_srv_conf_t *pscf; #if (NGX_MAIL_SSL) if (ngx_mail_starttls_only(s, c)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } #endif if (s->args.nelts != 2) { return NGX_MAIL_PARSE_INVALID_COMMAND; } pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module); if (!(pscf->auth_methods & NGX_MAIL_AUTH_APOP_ENABLED)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } arg = s->args.elts; 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); ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 apop: \"%V\" \"%V\"", &s->login, &s->passwd); s->auth_method = NGX_MAIL_AUTH_APOP; return NGX_DONE; } static ngx_int_t ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_int_t rc; ngx_mail_pop3_srv_conf_t *pscf; #if (NGX_MAIL_SSL) if (ngx_mail_starttls_only(s, c)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } #endif pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module); if (s->args.nelts == 0) { s->out = pscf->auth_capability; s->state = 0; return NGX_OK; } rc = ngx_mail_auth_parse(s, c); switch (rc) { case NGX_MAIL_AUTH_LOGIN: ngx_str_set(&s->out, pop3_username); s->mail_state = ngx_pop3_auth_login_username; return NGX_OK; case NGX_MAIL_AUTH_LOGIN_USERNAME: ngx_str_set(&s->out, pop3_password); s->mail_state = ngx_pop3_auth_login_password; return ngx_mail_auth_login_username(s, c, 1); case NGX_MAIL_AUTH_PLAIN: ngx_str_set(&s->out, pop3_next); s->mail_state = ngx_pop3_auth_plain; return NGX_OK; case NGX_MAIL_AUTH_CRAM_MD5: if (!(pscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) { s->mail_state = ngx_pop3_auth_cram_md5; return NGX_OK; } return NGX_ERROR; case NGX_MAIL_AUTH_EXTERNAL: if (!(pscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) { return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_str_set(&s->out, pop3_username); s->mail_state = ngx_pop3_auth_external; return NGX_OK; } return rc; }