| 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 - 2018 |
| 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, *l_data_file = NULL, *yield = NULL; |
| 39 | struct stat statbuf; |
| 40 | int j; |
| 41 | rmark reset_point; |
| 42 | |
| 43 | mbox_path = string_sprintf("%s/scan/%s/%s.eml", |
| 44 | spool_directory, message_id, message_id); |
| 45 | if (mbox_fname) *mbox_fname = mbox_path; |
| 46 | |
| 47 | reset_point = store_mark(); |
| 48 | |
| 49 | /* Skip creation if already spooled out as mbox file */ |
| 50 | if (!spool_mbox_ok) |
| 51 | { |
| 52 | /* create temp directory inside scan dir, directory_make works recursively */ |
| 53 | temp_string = string_sprintf("scan/%s", message_id); |
| 54 | if (!directory_make(spool_directory, temp_string, 0750, FALSE)) |
| 55 | { |
| 56 | log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno, |
| 57 | "scan directory %s/scan/%s", spool_directory, temp_string)); |
| 58 | goto OUT; |
| 59 | } |
| 60 | |
| 61 | /* open [message_id].eml file for writing */ |
| 62 | |
| 63 | if (!(mbox_file = modefopen(mbox_path, "wb", SPOOL_MODE))) |
| 64 | { |
| 65 | log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno, |
| 66 | "scan file %s", mbox_path)); |
| 67 | goto OUT; |
| 68 | } |
| 69 | |
| 70 | /* Generate mailbox headers. The $received_for variable is (up to at least |
| 71 | Exim 4.64) never set here, because it is only set when expanding the |
| 72 | contents of the Received: header line. However, the code below will use it |
| 73 | if it should become available in future. */ |
| 74 | |
| 75 | temp_string = expand_string( |
| 76 | US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n" |
| 77 | "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}" |
| 78 | "${if def:recipients{X-Envelope-To: ${recipients}\n}}"); |
| 79 | |
| 80 | if (temp_string) |
| 81 | if (fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file) != 1) |
| 82 | { |
| 83 | log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \ |
| 84 | mailbox headers to %s", mbox_path); |
| 85 | goto OUT; |
| 86 | } |
| 87 | |
| 88 | /* write all non-deleted header lines to mbox file */ |
| 89 | |
| 90 | for (header_line * my_headerlist = header_list; my_headerlist; |
| 91 | my_headerlist = my_headerlist->next) |
| 92 | if (my_headerlist->type != '*') |
| 93 | if (fwrite(my_headerlist->text, my_headerlist->slen, 1, mbox_file) != 1) |
| 94 | { |
| 95 | log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \ |
| 96 | message headers to %s", mbox_path); |
| 97 | goto OUT; |
| 98 | } |
| 99 | |
| 100 | /* End headers */ |
| 101 | if (fwrite("\n", 1, 1, mbox_file) != 1) |
| 102 | { |
| 103 | log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \ |
| 104 | message headers to %s", mbox_path); |
| 105 | goto OUT; |
| 106 | } |
| 107 | |
| 108 | /* Copy body file. If the main receive still has it open then it is holding |
| 109 | a lock, and we must not close it (which releases the lock), so just use the |
| 110 | global file handle. */ |
| 111 | if (source_file_override) |
| 112 | l_data_file = Ufopen(source_file_override, "rb"); |
| 113 | else if (spool_data_file) |
| 114 | l_data_file = spool_data_file; |
| 115 | else |
| 116 | { |
| 117 | message_subdir[1] = '\0'; |
| 118 | for (int i = 0; i < 2; i++) |
| 119 | { |
| 120 | set_subdir_str(message_subdir, message_id, i); |
| 121 | temp_string = spool_fname(US"input", message_subdir, message_id, US"-D"); |
| 122 | if ((l_data_file = Ufopen(temp_string, "rb"))) break; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | if (!l_data_file) |
| 127 | { |
| 128 | log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s", |
| 129 | message_id); |
| 130 | goto OUT; |
| 131 | } |
| 132 | |
| 133 | /* The code used to use this line, but it doesn't work in Cygwin. |
| 134 | |
| 135 | (void)fread(data_buffer, 1, 18, l_data_file); |
| 136 | |
| 137 | What's happening is that spool_mbox used to use an fread to jump over the |
| 138 | file header. That fails under Cygwin because the header is locked, but |
| 139 | doing an fseek succeeds. We have to output the leading newline |
| 140 | explicitly, because the one in the file is parted of the locked area. */ |
| 141 | |
| 142 | if (!source_file_override) |
| 143 | (void)fseek(l_data_file, SPOOL_DATA_START_OFFSET, SEEK_SET); |
| 144 | |
| 145 | do |
| 146 | { |
| 147 | uschar * s; |
| 148 | |
| 149 | if (!f.spool_file_wireformat || source_file_override) |
| 150 | j = fread(buffer, 1, sizeof(buffer), l_data_file); |
| 151 | else /* needs CRLF -> NL */ |
| 152 | if ((s = US fgets(CS buffer, sizeof(buffer), l_data_file))) |
| 153 | { |
| 154 | uschar * p = s + Ustrlen(s) - 1; |
| 155 | |
| 156 | if (*p == '\n' && p[-1] == '\r') |
| 157 | *--p = '\n'; |
| 158 | else if (*p == '\r') |
| 159 | ungetc(*p--, l_data_file); |
| 160 | |
| 161 | j = p - buffer; |
| 162 | } |
| 163 | else |
| 164 | j = 0; |
| 165 | |
| 166 | if (j > 0) |
| 167 | if (fwrite(buffer, j, 1, mbox_file) != 1) |
| 168 | { |
| 169 | log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \ |
| 170 | message body to %s", mbox_path); |
| 171 | goto OUT; |
| 172 | } |
| 173 | } while (j > 0); |
| 174 | |
| 175 | (void)fclose(mbox_file); |
| 176 | mbox_file = NULL; |
| 177 | |
| 178 | Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id)); |
| 179 | spooled_message_id[sizeof(spooled_message_id)-1] = '\0'; |
| 180 | spool_mbox_ok = 1; |
| 181 | } |
| 182 | |
| 183 | /* get the size of the mbox message and open [message_id].eml file for reading*/ |
| 184 | |
| 185 | if ( !(yield = Ufopen(mbox_path,"rb")) |
| 186 | || fstat(fileno(yield), &statbuf) != 0 |
| 187 | ) |
| 188 | log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno, |
| 189 | "scan file %s", mbox_path)); |
| 190 | else |
| 191 | *mbox_file_size = statbuf.st_size; |
| 192 | |
| 193 | OUT: |
| 194 | if (l_data_file && !spool_data_file) (void)fclose(l_data_file); |
| 195 | if (mbox_file) (void)fclose(mbox_file); |
| 196 | store_reset(reset_point); |
| 197 | return yield; |
| 198 | } |
| 199 | |
| 200 | |
| 201 | |
| 202 | |
| 203 | |
| 204 | /* remove mbox spool file and temp directory */ |
| 205 | void |
| 206 | unspool_mbox(void) |
| 207 | { |
| 208 | spam_ok = 0; |
| 209 | malware_ok = 0; |
| 210 | |
| 211 | if (spool_mbox_ok && !f.no_mbox_unspool) |
| 212 | { |
| 213 | uschar *file_path; |
| 214 | struct dirent *entry; |
| 215 | DIR *tempdir; |
| 216 | rmark reset_point = store_mark(); |
| 217 | uschar * mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id); |
| 218 | |
| 219 | if (!(tempdir = opendir(CS mbox_path))) |
| 220 | { |
| 221 | debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno)); |
| 222 | /* Just in case we still can: */ |
| 223 | rmdir(CS mbox_path); |
| 224 | return; |
| 225 | } |
| 226 | /* loop thru dir & delete entries */ |
| 227 | while((entry = readdir(tempdir))) |
| 228 | { |
| 229 | uschar *name = US entry->d_name; |
| 230 | int dummy; |
| 231 | if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue; |
| 232 | |
| 233 | file_path = string_sprintf("%s/%s", mbox_path, name); |
| 234 | debug_printf("unspool_mbox(): unlinking '%s'\n", file_path); |
| 235 | dummy = unlink(CS file_path); dummy = dummy; /* compiler quietening */ |
| 236 | } |
| 237 | |
| 238 | closedir(tempdir); |
| 239 | |
| 240 | /* remove directory */ |
| 241 | rmdir(CS mbox_path); |
| 242 | store_reset(reset_point); |
| 243 | } |
| 244 | spool_mbox_ok = 0; |
| 245 | } |
| 246 | |
| 247 | #endif |