Reduce number of places knowing about filename-construction for mbox file-for-scanning
[exim.git] / src / src / spool_mbox.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
6 * License: GPL
7 * Copyright (c) The Exim Maintainers 2016
8 */
9
10 /* Code for setting up a MBOX style spool file inside a /scan/<msgid>
11 sub directory of exim's spool directory. */
12
13 #include "exim.h"
14 #ifdef WITH_CONTENT_SCAN
15
16 extern int malware_ok;
17 extern int spam_ok;
18
19 int spool_mbox_ok = 0;
20 uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
21
22 /*
23 Create an MBOX-style message file from the spooled files.
24
25 Returns a pointer to the FILE, and puts the size in bytes into mbox_file_size.
26 If mbox_fname is non-null, fill in a pointer to the name.
27 Normally, source_file_override is NULL
28 */
29
30 FILE *
31 spool_mbox(unsigned long *mbox_file_size, const uschar *source_file_override,
32 uschar ** mbox_fname)
33 {
34 uschar message_subdir[2];
35 uschar buffer[16384];
36 uschar *temp_string;
37 uschar *mbox_path;
38 FILE *mbox_file = NULL;
39 FILE *data_file = NULL;
40 FILE *yield = NULL;
41 header_line *my_headerlist;
42 struct stat statbuf;
43 int i, j;
44 void *reset_point;
45
46 mbox_path = string_sprintf("%s/scan/%s/%s.eml",
47 spool_directory, message_id, message_id);
48 if (mbox_fname) *mbox_fname = mbox_path;
49
50 reset_point = store_get(0);
51
52 /* Skip creation if already spooled out as mbox file */
53 if (!spool_mbox_ok)
54 {
55 /* create temp directory inside scan dir, directory_make works recursively */
56 temp_string = string_sprintf("scan/%s", message_id);
57 if (!directory_make(spool_directory, temp_string, 0750, FALSE))
58 {
59 log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
60 "scan directory %s/scan/%s", spool_directory, temp_string));
61 goto OUT;
62 }
63
64 /* open [message_id].eml file for writing */
65 mbox_file = modefopen(mbox_path, "wb", SPOOL_MODE);
66 if (mbox_file == NULL)
67 {
68 log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
69 "scan file %s", mbox_path));
70 goto OUT;
71 }
72
73 /* Generate mailbox headers. The $received_for variable is (up to at least
74 Exim 4.64) never set here, because it is only set when expanding the
75 contents of the Received: header line. However, the code below will use it
76 if it should become available in future. */
77
78 temp_string = expand_string(
79 US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"
80 "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}"
81 "${if def:recipients{X-Envelope-To: ${recipients}\n}}");
82
83 if (temp_string != NULL)
84 {
85 i = fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file);
86 if (i != 1)
87 {
88 log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
89 mailbox headers to %s", mbox_path);
90 goto OUT;
91 }
92 }
93
94 /* write all header lines to mbox file */
95 my_headerlist = header_list;
96 for (my_headerlist = header_list; my_headerlist != NULL;
97 my_headerlist = my_headerlist->next)
98 {
99 /* skip deleted headers */
100 if (my_headerlist->type == '*') continue;
101
102 i = fwrite(my_headerlist->text, my_headerlist->slen, 1, mbox_file);
103 if (i != 1)
104 {
105 log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
106 message headers to %s", mbox_path);
107 goto OUT;
108 }
109 }
110
111 /* End headers */
112 if (fwrite("\n", 1, 1, mbox_file) != 1)
113 {
114 log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
115 message headers to %s", mbox_path);
116 goto OUT;
117 }
118
119 /* copy body file */
120 if (!source_file_override)
121 {
122 message_subdir[1] = '\0';
123 for (i = 0; i < 2; i++)
124 {
125 message_subdir[0] = split_spool_directory == (i == 0) ? message_id[5] : 0;
126 temp_string = spool_fname(US"input", message_subdir, message_id, US"-D");
127 if ((data_file = Ufopen(temp_string, "rb"))) break;
128 }
129 }
130 else
131 data_file = Ufopen(source_file_override, "rb");
132
133 if (!data_file)
134 {
135 log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
136 message_id);
137 goto OUT;
138 }
139
140 /* The code used to use this line, but it doesn't work in Cygwin.
141
142 (void)fread(data_buffer, 1, 18, data_file);
143
144 What's happening is that spool_mbox used to use an fread to jump over the
145 file header. That fails under Cygwin because the header is locked, but
146 doing an fseek succeeds. We have to output the leading newline
147 explicitly, because the one in the file is parted of the locked area. */
148
149 if (!source_file_override)
150 (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
151
152 do
153 {
154 j = fread(buffer, 1, sizeof(buffer), data_file);
155
156 if (j > 0)
157 {
158 i = fwrite(buffer, j, 1, mbox_file);
159 if (i != 1)
160 {
161 log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
162 message body to %s", mbox_path);
163 goto OUT;
164 }
165 }
166 } while (j > 0);
167
168 (void)fclose(mbox_file);
169 mbox_file = NULL;
170
171 Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
172 spooled_message_id[sizeof(spooled_message_id)-1] = '\0';
173 spool_mbox_ok = 1;
174 }
175
176 /* get the size of the mbox message and open [message_id].eml file for reading*/
177
178 if ( !(yield = Ufopen(mbox_path,"rb"))
179 || fstat(fileno(yield), &statbuf) != 0
180 )
181 log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
182 "scan file %s", mbox_path));
183 else
184 *mbox_file_size = statbuf.st_size;
185
186 OUT:
187 if (data_file) (void)fclose(data_file);
188 if (mbox_file) (void)fclose(mbox_file);
189 store_reset(reset_point);
190 return yield;
191 }
192
193
194
195
196
197 /* remove mbox spool file and temp directory */
198 void
199 unspool_mbox(void)
200 {
201 spam_ok = 0;
202 malware_ok = 0;
203
204 if (spool_mbox_ok && !no_mbox_unspool)
205 {
206 uschar *mbox_path;
207 uschar *file_path;
208 struct dirent *entry;
209 DIR *tempdir;
210
211 mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
212
213 tempdir = opendir(CS mbox_path);
214 if (!tempdir)
215 {
216 debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
217 /* Just in case we still can: */
218 rmdir(CS mbox_path);
219 return;
220 }
221 /* loop thru dir & delete entries */
222 while((entry = readdir(tempdir)) != NULL)
223 {
224 uschar *name = US entry->d_name;
225 int dummy;
226 if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
227
228 file_path = string_sprintf("%s/%s", mbox_path, name);
229 debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
230 dummy = unlink(CS file_path);
231 }
232
233 closedir(tempdir);
234
235 /* remove directory */
236 rmdir(CS mbox_path);
237 store_reset(mbox_path);
238 }
239 spool_mbox_ok = 0;
240 }
241
242 #endif