Mail: max_errors directive.
Similarly to smtpd_hard_error_limit in Postfix and smtp_max_unknown_commands
in Exim, specifies the number of errors after which the connection is closed.
diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
index 07104df..21178c3 100644
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -115,6 +115,8 @@
ngx_msec_t timeout;
ngx_msec_t resolver_timeout;
+ ngx_uint_t max_errors;
+
ngx_str_t server_name;
u_char *file_name;
@@ -231,6 +233,7 @@
ngx_uint_t command;
ngx_array_t args;
+ ngx_uint_t errors;
ngx_uint_t login_attempt;
/* used to parse POP3/IMAP/SMTP command */
diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c
index 4083124..115671c 100644
--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -85,6 +85,13 @@
offsetof(ngx_mail_core_srv_conf_t, resolver_timeout),
NULL },
+ { ngx_string("max_errors"),
+ NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
+ ngx_conf_set_num_slot,
+ NGX_MAIL_SRV_CONF_OFFSET,
+ offsetof(ngx_mail_core_srv_conf_t, max_errors),
+ NULL },
+
ngx_null_command
};
@@ -163,6 +170,8 @@
cscf->timeout = NGX_CONF_UNSET_MSEC;
cscf->resolver_timeout = NGX_CONF_UNSET_MSEC;
+ cscf->max_errors = NGX_CONF_UNSET_UINT;
+
cscf->resolver = NGX_CONF_UNSET_PTR;
cscf->file_name = cf->conf_file->file.name.data;
@@ -182,6 +191,7 @@
ngx_conf_merge_msec_value(conf->resolver_timeout, prev->resolver_timeout,
30000);
+ ngx_conf_merge_uint_value(conf->max_errors, prev->max_errors, 5);
ngx_conf_merge_str_value(conf->server_name, prev->server_name, "");
diff --git a/src/mail/ngx_mail_handler.c b/src/mail/ngx_mail_handler.c
index 57503e9..246ba97 100644
--- a/src/mail/ngx_mail_handler.c
+++ b/src/mail/ngx_mail_handler.c
@@ -874,7 +874,20 @@
return NGX_MAIL_PARSE_INVALID_COMMAND;
}
- if (rc == NGX_IMAP_NEXT || rc == NGX_MAIL_PARSE_INVALID_COMMAND) {
+ if (rc == NGX_MAIL_PARSE_INVALID_COMMAND) {
+
+ s->errors++;
+
+ if (s->errors >= cscf->max_errors) {
+ ngx_log_error(NGX_LOG_INFO, c->log, 0,
+ "client sent too many invalid commands");
+ s->quit = 1;
+ }
+
+ return rc;
+ }
+
+ if (rc == NGX_IMAP_NEXT) {
return rc;
}