ngx_mail_smtp_module.c revision e18a033b
1
2/*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8#include <ngx_config.h>
9#include <ngx_core.h>
10#include <ngx_event.h>
11#include <ngx_mail.h>
12#include <ngx_mail_smtp_module.h>
13
14
15static void *ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf);
16static char *ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent,
17    void *child);
18
19
20static ngx_conf_bitmask_t  ngx_mail_smtp_auth_methods[] = {
21    { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED },
22    { ngx_string("login"), NGX_MAIL_AUTH_LOGIN_ENABLED },
23    { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED },
24    { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED },
25    { ngx_string("none"), NGX_MAIL_AUTH_NONE_ENABLED },
26    { ngx_null_string, 0 }
27};
28
29
30static ngx_str_t  ngx_mail_smtp_auth_methods_names[] = {
31    ngx_string("PLAIN"),
32    ngx_string("LOGIN"),
33    ngx_null_string,  /* APOP */
34    ngx_string("CRAM-MD5"),
35    ngx_string("EXTERNAL"),
36    ngx_null_string   /* NONE */
37};
38
39
40static ngx_mail_protocol_t  ngx_mail_smtp_protocol = {
41    ngx_string("smtp"),
42    { 25, 465, 587, 0 },
43    NGX_MAIL_SMTP_PROTOCOL,
44
45    ngx_mail_smtp_init_session,
46    ngx_mail_smtp_init_protocol,
47    ngx_mail_smtp_parse_command,
48    ngx_mail_smtp_auth_state,
49
50    ngx_string("451 4.3.2 Internal server error" CRLF),
51    ngx_string("421 4.7.1 SSL certificate error" CRLF),
52    ngx_string("421 4.7.1 No required SSL certificate" CRLF)
53};
54
55
56static ngx_command_t  ngx_mail_smtp_commands[] = {
57
58    { ngx_string("smtp_client_buffer"),
59      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
60      ngx_conf_set_size_slot,
61      NGX_MAIL_SRV_CONF_OFFSET,
62      offsetof(ngx_mail_smtp_srv_conf_t, client_buffer_size),
63      NULL },
64
65    { ngx_string("smtp_greeting_delay"),
66      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1,
67      ngx_conf_set_msec_slot,
68      NGX_MAIL_SRV_CONF_OFFSET,
69      offsetof(ngx_mail_smtp_srv_conf_t, greeting_delay),
70      NULL },
71
72    { ngx_string("smtp_capabilities"),
73      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
74      ngx_mail_capabilities,
75      NGX_MAIL_SRV_CONF_OFFSET,
76      offsetof(ngx_mail_smtp_srv_conf_t, capabilities),
77      NULL },
78
79    { ngx_string("smtp_auth"),
80      NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
81      ngx_conf_set_bitmask_slot,
82      NGX_MAIL_SRV_CONF_OFFSET,
83      offsetof(ngx_mail_smtp_srv_conf_t, auth_methods),
84      &ngx_mail_smtp_auth_methods },
85
86      ngx_null_command
87};
88
89
90static ngx_mail_module_t  ngx_mail_smtp_module_ctx = {
91    &ngx_mail_smtp_protocol,               /* protocol */
92
93    NULL,                                  /* create main configuration */
94    NULL,                                  /* init main configuration */
95
96    ngx_mail_smtp_create_srv_conf,         /* create server configuration */
97    ngx_mail_smtp_merge_srv_conf           /* merge server configuration */
98};
99
100
101ngx_module_t  ngx_mail_smtp_module = {
102    NGX_MODULE_V1,
103    &ngx_mail_smtp_module_ctx,             /* module context */
104    ngx_mail_smtp_commands,                /* module directives */
105    NGX_MAIL_MODULE,                       /* module type */
106    NULL,                                  /* init master */
107    NULL,                                  /* init module */
108    NULL,                                  /* init process */
109    NULL,                                  /* init thread */
110    NULL,                                  /* exit thread */
111    NULL,                                  /* exit process */
112    NULL,                                  /* exit master */
113    NGX_MODULE_V1_PADDING
114};
115
116
117static void *
118ngx_mail_smtp_create_srv_conf(ngx_conf_t *cf)
119{
120    ngx_mail_smtp_srv_conf_t  *sscf;
121
122    sscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_smtp_srv_conf_t));
123    if (sscf == NULL) {
124        return NULL;
125    }
126
127    sscf->client_buffer_size = NGX_CONF_UNSET_SIZE;
128    sscf->greeting_delay = NGX_CONF_UNSET_MSEC;
129
130    if (ngx_array_init(&sscf->capabilities, cf->pool, 4, sizeof(ngx_str_t))
131        != NGX_OK)
132    {
133        return NULL;
134    }
135
136    return sscf;
137}
138
139
140static char *
141ngx_mail_smtp_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
142{
143    ngx_mail_smtp_srv_conf_t *prev = parent;
144    ngx_mail_smtp_srv_conf_t *conf = child;
145
146    u_char                    *p, *auth, *last;
147    size_t                     size;
148    ngx_str_t                 *c;
149    ngx_uint_t                 i, m, auth_enabled;
150    ngx_mail_core_srv_conf_t  *cscf;
151
152    ngx_conf_merge_size_value(conf->client_buffer_size,
153                              prev->client_buffer_size,
154                              (size_t) ngx_pagesize);
155
156    ngx_conf_merge_msec_value(conf->greeting_delay,
157                              prev->greeting_delay, 0);
158
159    ngx_conf_merge_bitmask_value(conf->auth_methods,
160                              prev->auth_methods,
161                              (NGX_CONF_BITMASK_SET
162                               |NGX_MAIL_AUTH_PLAIN_ENABLED
163                               |NGX_MAIL_AUTH_LOGIN_ENABLED));
164
165
166    cscf = ngx_mail_conf_get_module_srv_conf(cf, ngx_mail_core_module);
167
168    size = sizeof("220  ESMTP ready" CRLF) - 1 + cscf->server_name.len;
169
170    p = ngx_pnalloc(cf->pool, size);
171    if (p == NULL) {
172        return NGX_CONF_ERROR;
173    }
174
175    conf->greeting.len = size;
176    conf->greeting.data = p;
177
178    *p++ = '2'; *p++ = '2'; *p++ = '0'; *p++ = ' ';
179    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
180    ngx_memcpy(p, " ESMTP ready" CRLF, sizeof(" ESMTP ready" CRLF) - 1);
181
182
183    size = sizeof("250 " CRLF) - 1 + cscf->server_name.len;
184
185    p = ngx_pnalloc(cf->pool, size);
186    if (p == NULL) {
187        return NGX_CONF_ERROR;
188    }
189
190    conf->server_name.len = size;
191    conf->server_name.data = p;
192
193    *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' ';
194    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
195    *p++ = CR; *p = LF;
196
197
198    if (conf->capabilities.nelts == 0) {
199        conf->capabilities = prev->capabilities;
200    }
201
202    size = sizeof("250-") - 1 + cscf->server_name.len + sizeof(CRLF) - 1;
203
204    c = conf->capabilities.elts;
205    for (i = 0; i < conf->capabilities.nelts; i++) {
206        size += sizeof("250 ") - 1 + c[i].len + sizeof(CRLF) - 1;
207    }
208
209    auth_enabled = 0;
210
211    for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
212         m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
213         m <<= 1, i++)
214    {
215        if (m & conf->auth_methods) {
216            size += 1 + ngx_mail_smtp_auth_methods_names[i].len;
217            auth_enabled = 1;
218        }
219    }
220
221    if (auth_enabled) {
222        size += sizeof("250 AUTH") - 1 + sizeof(CRLF) - 1;
223    }
224
225    p = ngx_pnalloc(cf->pool, size);
226    if (p == NULL) {
227        return NGX_CONF_ERROR;
228    }
229
230    conf->capability.len = size;
231    conf->capability.data = p;
232
233    last = p;
234
235    *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-';
236    p = ngx_cpymem(p, cscf->server_name.data, cscf->server_name.len);
237    *p++ = CR; *p++ = LF;
238
239    for (i = 0; i < conf->capabilities.nelts; i++) {
240        last = p;
241        *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = '-';
242        p = ngx_cpymem(p, c[i].data, c[i].len);
243        *p++ = CR; *p++ = LF;
244    }
245
246    auth = p;
247
248    if (auth_enabled) {
249        last = p;
250
251        *p++ = '2'; *p++ = '5'; *p++ = '0'; *p++ = ' ';
252        *p++ = 'A'; *p++ = 'U'; *p++ = 'T'; *p++ = 'H';
253
254        for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0;
255             m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED;
256             m <<= 1, i++)
257        {
258            if (m & conf->auth_methods) {
259                *p++ = ' ';
260                p = ngx_cpymem(p, ngx_mail_smtp_auth_methods_names[i].data,
261                               ngx_mail_smtp_auth_methods_names[i].len);
262            }
263        }
264
265        *p++ = CR; *p = LF;
266
267    } else {
268        last[3] = ' ';
269    }
270
271    size += sizeof("250 STARTTLS" CRLF) - 1;
272
273    p = ngx_pnalloc(cf->pool, size);
274    if (p == NULL) {
275        return NGX_CONF_ERROR;
276    }
277
278    conf->starttls_capability.len = size;
279    conf->starttls_capability.data = p;
280
281    p = ngx_cpymem(p, conf->capability.data, conf->capability.len);
282
283    ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1);
284
285    p = conf->starttls_capability.data
286        + (last - conf->capability.data) + 3;
287    *p = '-';
288
289    size = (auth - conf->capability.data)
290            + sizeof("250 STARTTLS" CRLF) - 1;
291
292    p = ngx_pnalloc(cf->pool, size);
293    if (p == NULL) {
294        return NGX_CONF_ERROR;
295    }
296
297    conf->starttls_only_capability.len = size;
298    conf->starttls_only_capability.data = p;
299
300    p = ngx_cpymem(p, conf->capability.data, auth - conf->capability.data);
301
302    ngx_memcpy(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1);
303
304    if (last < auth) {
305        p = conf->starttls_only_capability.data
306            + (last - conf->capability.data) + 3;
307        *p = '-';
308    }
309
310    return NGX_CONF_OK;
311}
312