1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
Patch-Source: https://github.com/nginx/nginx/commit/173f16f736c10eae46cd15dd861b04b82d91a37a
commit 173f16f736c10eae46cd15dd861b04b82d91a37a
Author: Maxim Dounin <mdounin@mdounin.ru>
Date: Wed May 19 03:13:31 2021 +0300
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 07104df6..21178c3e 100644
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -115,6 +115,8 @@ typedef struct {
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 @@ typedef struct {
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 40831242..115671ca 100644
--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -85,6 +85,13 @@ static ngx_command_t ngx_mail_core_commands[] = {
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 @@ ngx_mail_core_create_srv_conf(ngx_conf_t *cf)
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_mail_core_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
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 57503e9a..246ba97c 100644
--- a/src/mail/ngx_mail_handler.c
+++ b/src/mail/ngx_mail_handler.c
@@ -874,7 +874,20 @@ ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c)
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;
}
|
