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/* Copyright (c) 2005-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "ioloop.h"
#include "hostpid.h"
#include "istream.h"
#include "ostream.h"
#include "str.h"
#include "str-sanitize.h"
#include "var-expand.h"
#include "message-date.h"
#include "message-size.h"
#include "message-address.h"
#include "istream-header-filter.h"
#include "mail-storage.h"
#include "mail-storage-settings.h"
#include "iostream-ssl.h"
#include "lda-settings.h"
#include "mail-deliver.h"
#include "smtp-address.h"
#include "smtp-submit.h"
#include "mail-send.h"
#include <sys/wait.h>
static const struct var_expand_table *
get_var_expand_table(struct mail *mail,
const struct smtp_address *recipient,
const char *reason)
{
const char *subject;
if (mail_get_first_header(mail, "Subject", &subject) <= 0)
subject = "";
const struct var_expand_table stack_tab[] = {
{ 'n', "\r\n", "crlf" },
{ 'r', reason, "reason" },
{ 's', str_sanitize(subject, 80), "subject" },
{ 't', smtp_address_encode(recipient), "to" },
{ '\0', NULL, NULL }
};
struct var_expand_table *tab;
tab = t_malloc_no0(sizeof(stack_tab));
memcpy(tab, stack_tab, sizeof(stack_tab));
return tab;
}
int mail_send_rejection(struct mail_deliver_context *ctx,
const struct smtp_address *recipient,
const char *reason)
{
struct mail_user *user = ctx->rcpt_user;
struct ssl_iostream_settings ssl_set;
struct mail *mail = ctx->src_mail;
struct istream *input;
struct smtp_submit_input smtp_input;
struct smtp_submit *smtp_submit;
struct ostream *output;
const struct message_address *postmaster_addr;
const struct smtp_address *return_addr;
const char *hdr, *value, *msgid, *orig_msgid, *boundary, *error;
const struct var_expand_table *vtable;
string_t *str;
int ret;
if (mail_get_first_header(mail, "Message-ID", &orig_msgid) < 0)
orig_msgid = NULL;
if (mail_get_first_header(mail, "Auto-Submitted", &value) > 0 &&
strcasecmp(value, "no") != 0) {
i_info("msgid=%s: Auto-submitted message discarded: %s",
orig_msgid == NULL ? "" : str_sanitize(orig_msgid, 80),
str_sanitize(reason, 512));
return 0;
}
return_addr = mail_deliver_get_return_address(ctx);
if (smtp_address_isnull(return_addr)) {
i_info("msgid=%s: Return-Path missing, rejection reason: %s",
orig_msgid == NULL ? "" : str_sanitize(orig_msgid, 80),
str_sanitize(reason, 512));
return 0;
}
if (!mail_user_get_postmaster_address(user, &postmaster_addr, &error)) {
i_error("msgid=%s: Invalid postmaster_address - can't send rejection: %s",
orig_msgid == NULL ? "" : str_sanitize(orig_msgid, 80), error);
return -1;
}
e_debug(mail_event(mail), "Sending a rejection to <%s>: %s",
smtp_address_encode(return_addr),
str_sanitize(reason, 512));
vtable = get_var_expand_table(mail, recipient, reason);
mail_user_init_ssl_client_settings(user, &ssl_set);
i_zero(&smtp_input);
smtp_input.ssl = &ssl_set;
smtp_submit = smtp_submit_init_simple(&smtp_input, ctx->smtp_set, NULL);
smtp_submit_add_rcpt(smtp_submit, return_addr);
output = smtp_submit_send(smtp_submit);
msgid = mail_deliver_get_new_message_id(ctx);
boundary = t_strdup_printf("%s/%s", my_pid, user->set->hostname);
str = t_str_new(512);
str_printfa(str, "Message-ID: %s\r\n", msgid);
str_printfa(str, "Date: %s\r\n", message_date_create(ioloop_time));
str_append(str, "From: ");
message_address_write(str, postmaster_addr);
str_append(str, "\r\n");
str_printfa(str, "To: <%s>\r\n", smtp_address_encode(return_addr));
str_append(str, "MIME-Version: 1.0\r\n");
str_printfa(str, "Content-Type: "
"multipart/report; report-type=%s;\r\n"
"\tboundary=\"%s\"\r\n",
ctx->dsn ? "delivery-status" : "disposition-notification",
boundary);
str_append(str, "Subject: ");
if (var_expand(str, ctx->set->rejection_subject,
vtable, &error) <= 0) {
i_error("Failed to expand rejection_subject=%s: %s",
ctx->set->rejection_subject, error);
}
str_append(str, "\r\n");
str_append(str, "Auto-Submitted: auto-replied (rejected)\r\n");
str_append(str, "Precedence: bulk\r\n");
str_append(str, "\r\nThis is a MIME-encapsulated message\r\n\r\n");
/* human readable status report */
str_printfa(str, "--%s\r\n", boundary);
str_append(str, "Content-Type: text/plain; charset=utf-8\r\n");
str_append(str, "Content-Disposition: inline\r\n");
str_append(str, "Content-Transfer-Encoding: 8bit\r\n\r\n");
if (var_expand(str, ctx->set->rejection_reason,
vtable, &error) <= 0) {
i_error("Failed to expand rejection_reason=%s: %s",
ctx->set->rejection_reason, error);
}
str_append(str, "\r\n");
if (ctx->dsn) {
/* DSN status report: For LDA rejects. currently only used when
user is out of quota */
str_printfa(str, "--%s\r\n"
"Content-Type: message/delivery-status\r\n\r\n",
boundary);
str_printfa(str, "Reporting-MTA: dns; %s\r\n", user->set->hostname);
if (mail_get_first_header(mail, "Original-Recipient", &hdr) > 0)
str_printfa(str, "Original-Recipient: rfc822; %s\r\n", hdr);
str_printfa(str, "Final-Recipient: rfc822; %s\r\n",
smtp_address_encode(recipient));
str_append(str, "Action: failed\r\n");
str_printfa(str, "Status: %s\r\n", ctx->mailbox_full ? "5.2.2" : "5.2.0");
} else {
/* MDN status report: For Sieve "reject" */
str_printfa(str, "--%s\r\n"
"Content-Type: message/disposition-notification\r\n\r\n",
boundary);
str_printfa(str, "Reporting-UA: %s; Dovecot Mail Delivery Agent\r\n",
user->set->hostname);
if (mail_get_first_header(mail, "Original-Recipient", &hdr) > 0)
str_printfa(str, "Original-Recipient: rfc822; %s\r\n", hdr);
str_printfa(str, "Final-Recipient: rfc822; %s\r\n",
smtp_address_encode(recipient));
if (orig_msgid != NULL)
str_printfa(str, "Original-Message-ID: %s\r\n", orig_msgid);
str_append(str, "Disposition: "
"automatic-action/MDN-sent-automatically; deleted\r\n");
}
str_append(str, "\r\n");
/* original message's headers */
str_printfa(str, "--%s\r\nContent-Type: message/rfc822\r\n\r\n", boundary);
o_stream_nsend(output, str_data(str), str_len(str));
if (mail_get_hdr_stream(mail, NULL, &input) == 0) {
/* Note: If you add more headers, they need to be sorted.
We'll drop Content-Type because we're not including the message
body, and having a multipart Content-Type may confuse some
MIME parsers when they don't see the message boundaries. */
static const char *const exclude_headers[] = {
"Content-Type"
};
input = i_stream_create_header_filter(input,
HEADER_FILTER_EXCLUDE | HEADER_FILTER_NO_CR |
HEADER_FILTER_HIDE_BODY, exclude_headers,
N_ELEMENTS(exclude_headers),
*null_header_filter_callback, NULL);
o_stream_nsend_istream(output, input);
i_stream_unref(&input);
}
str_truncate(str, 0);
str_printfa(str, "\r\n\r\n--%s--\r\n", boundary);
o_stream_nsend(output, str_data(str), str_len(str));
if ((ret = smtp_submit_run(smtp_submit, &error)) < 0) {
i_error("msgid=%s: Temporarily failed to send rejection: %s",
orig_msgid == NULL ? "" : str_sanitize(orig_msgid, 80),
str_sanitize(error, 512));
} else if (ret == 0) {
i_info("msgid=%s: Permanently failed to send rejection: %s",
orig_msgid == NULL ? "" : str_sanitize(orig_msgid, 80),
str_sanitize(error, 512));
}
smtp_submit_deinit(&smtp_submit);
return ret < 0 ? -1 : 0;
}
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