1 /* $NetBSD: bounce_notify_service.c,v 1.1.1.1 2009/06/23 10:08:42 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* bounce_notify_service 3 6 /* SUMMARY 7 /* send non-delivery report to sender, server side 8 /* SYNOPSIS 9 /* #include "bounce_service.h" 10 /* 11 /* int bounce_notify_service(flags, queue_name, queue_id, encoding, 12 /* sender, dsn_envid, dsn_ret, templates) 13 /* int flags; 14 /* char *queue_name; 15 /* char *queue_id; 16 /* char *encoding; 17 /* char *sender; 18 /* char *dsn_envid; 19 /* int dsn_ret; 20 /* BOUNCE_TEMPLATES *templates; 21 /* DESCRIPTION 22 /* This module implements the server side of the bounce_flush() 23 /* (send bounce message) request. 24 /* 25 /* When a message bounces, a full copy is sent to the originator, 26 /* and an optional copy of the diagnostics with message headers is 27 /* sent to the postmaster. The result is non-zero when the operation 28 /* should be tried again. Otherwise, the logfile is removed. 29 /* 30 /* When a bounce is sent, the sender address is the empty 31 /* address. When a bounce bounces, an optional double bounce 32 /* with the entire undeliverable mail is sent to the postmaster, 33 /* with as sender address the double bounce address. 34 /* DIAGNOSTICS 35 /* Fatal error: error opening existing file. 36 /* BUGS 37 /* SEE ALSO 38 /* bounce(3) basic bounce service client interface 39 /* LICENSE 40 /* .ad 41 /* .fi 42 /* The Secure Mailer license must be distributed with this software. 43 /* AUTHOR(S) 44 /* Wietse Venema 45 /* IBM T.J. Watson Research 46 /* P.O. Box 704 47 /* Yorktown Heights, NY 10598, USA 48 /*--*/ 49 50 /* System library. */ 51 52 #include <sys_defs.h> 53 #include <fcntl.h> 54 #include <errno.h> 55 #include <string.h> 56 #include <ctype.h> 57 58 #ifdef STRCASECMP_IN_STRINGS_H 59 #include <strings.h> 60 #endif 61 62 /* Utility library. */ 63 64 #include <msg.h> 65 #include <vstream.h> 66 #include <name_mask.h> 67 68 /* Global library. */ 69 70 #include <mail_params.h> 71 #include <mail_queue.h> 72 #include <post_mail.h> 73 #include <mail_addr.h> 74 #include <mail_error.h> 75 #include <bounce.h> 76 #include <dsn_mask.h> 77 78 /* Application-specific. */ 79 80 #include "bounce_service.h" 81 82 #define STR vstring_str 83 84 /* bounce_notify_service - send a bounce */ 85 86 int bounce_notify_service(int flags, char *service, char *queue_name, 87 char *queue_id, char *encoding, 88 char *recipient, char *dsn_envid, 89 int dsn_ret, BOUNCE_TEMPLATES *ts) 90 { 91 BOUNCE_INFO *bounce_info; 92 int bounce_status = 1; 93 int postmaster_status = 1; 94 VSTREAM *bounce; 95 int notify_mask = name_mask(VAR_NOTIFY_CLASSES, mail_error_masks, 96 var_notify_classes); 97 VSTRING *new_id = vstring_alloc(10); 98 char *postmaster; 99 int count; 100 101 /* 102 * Initialize. Open queue file, bounce log, etc. 103 * 104 * XXX DSN The bounce service produces RFC 3464-style "failed mail" reports 105 * from information in two following types of logfile: 106 * 107 * 1 - bounce: this file is used for RFC 3464-style reports of permanent 108 * delivery errors by the bounce(8) service. This reports to the sender 109 * all recipients that have no DSN NOTIFY information (compatibility) and 110 * all recipients that have DSN NOTIFY=FAILURE; this reports to 111 * postmaster all recipients, if postmaster notification is enabled. 112 * 113 * 2 - defer: this file is used for three types of report: 114 * 115 * 2a) RFC 3464-style "mail is too old" reports by the bounce(8) service. 116 * This reports to the sender all recipients that have no DSN NOTIFY 117 * information (compatibility) and all recipients that have DSN 118 * NOTIFY=FAILURE; this reports to postmaster all recipients, if 119 * postmaster notification is enabled. 120 * 121 * Other reports that other servers produce from the defer logfile: 122 * 123 * 2b) On-demand reports of all delayed deliveries by the showq(8) service 124 * and mailq(1) command. This reports all recipients that have a 125 * transient delivery error. 126 * 127 * 2c) RFC 3464-style "delayed mail" notifications by the defer(8) service. 128 * This reports to the sender all recipients that have no DSN NOTIFY 129 * information (compatibility) and all recipients that have DSN 130 * NOTIFY=DELAY; this reports to postmaster all recipients, if postmaster 131 * notification is enabled. 132 */ 133 bounce_info = bounce_mail_init(service, queue_name, queue_id, 134 encoding, dsn_envid, ts->failure); 135 136 #define NULL_SENDER MAIL_ADDR_EMPTY /* special address */ 137 #define NULL_TRACE_FLAGS 0 138 139 /* 140 * The choice of sender address depends on the recipient address. For a 141 * single bounce (a non-delivery notification to the message originator), 142 * the sender address is the empty string. For a double bounce (typically 143 * a failed single bounce, or a postmaster notification that was produced 144 * by any of the mail processes) the sender address is defined by the 145 * var_double_bounce_sender configuration variable. When a double bounce 146 * cannot be delivered, the queue manager blackholes the resulting triple 147 * bounce message. 148 */ 149 150 /* 151 * Double bounce failed. Never send a triple bounce. 152 * 153 * However, this does not prevent double bounces from bouncing on other 154 * systems. In order to cope with this, either the queue manager must 155 * recognize the double-bounce recipient address and discard mail, or 156 * every delivery agent must recognize the double-bounce sender address 157 * and substitute something else so mail does not come back at us. 158 */ 159 if (strcasecmp(recipient, mail_addr_double_bounce()) == 0) { 160 msg_warn("%s: undeliverable postmaster notification discarded", 161 queue_id); 162 bounce_status = 0; 163 } 164 165 /* 166 * Single bounce failed. Optionally send a double bounce to postmaster, 167 * subject to notify_classes restrictions. 168 */ 169 #define ANY_BOUNCE (MAIL_ERROR_2BOUNCE | MAIL_ERROR_BOUNCE) 170 #define SEND_POSTMASTER_ANY_BOUNCE_NOTICE (notify_mask & ANY_BOUNCE) 171 172 else if (*recipient == 0) { 173 if (!SEND_POSTMASTER_ANY_BOUNCE_NOTICE) { 174 bounce_status = 0; 175 } else { 176 postmaster = var_2bounce_rcpt; 177 if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(), 178 postmaster, 179 INT_FILT_MASK_BOUNCE, 180 NULL_TRACE_FLAGS, 181 new_id)) != 0) { 182 183 /* 184 * Double bounce to Postmaster. This is the last opportunity 185 * for this message to be delivered. Send the text with 186 * reason for the bounce, and the headers of the original 187 * message. Don't bother sending the boiler-plate text. 188 */ 189 count = -1; 190 if (bounce_header(bounce, bounce_info, postmaster, 191 POSTMASTER_COPY) == 0 192 && (count = bounce_diagnostic_log(bounce, bounce_info, 193 DSN_NOTIFY_OVERRIDE)) > 0 194 && bounce_header_dsn(bounce, bounce_info) == 0 195 && bounce_diagnostic_dsn(bounce, bounce_info, 196 DSN_NOTIFY_OVERRIDE) > 0) { 197 bounce_original(bounce, bounce_info, DSN_RET_FULL); 198 bounce_status = post_mail_fclose(bounce); 199 if (bounce_status == 0) 200 msg_info("%s: postmaster non-delivery notification: %s", 201 queue_id, STR(new_id)); 202 } else { 203 /* No applicable recipients found - cancel this notice. */ 204 (void) vstream_fclose(bounce); 205 if (count == 0) 206 bounce_status = 0; 207 } 208 } 209 } 210 } 211 212 /* 213 * Non-bounce failed. Send a single bounce to the sender, subject to DSN 214 * NOTIFY restrictions. 215 */ 216 else { 217 if ((bounce = post_mail_fopen_nowait(NULL_SENDER, recipient, 218 INT_FILT_MASK_BOUNCE, 219 NULL_TRACE_FLAGS, 220 new_id)) != 0) { 221 222 /* 223 * Send the bounce message header, some boilerplate text that 224 * pretends that we are a polite mail system, the text with 225 * reason for the bounce, and a copy of the original message. 226 */ 227 count = -1; 228 if (bounce_header(bounce, bounce_info, recipient, 229 NO_POSTMASTER_COPY) == 0 230 && bounce_boilerplate(bounce, bounce_info) == 0 231 && (count = bounce_diagnostic_log(bounce, bounce_info, 232 DSN_NOTIFY_FAILURE)) > 0 233 && bounce_header_dsn(bounce, bounce_info) == 0 234 && bounce_diagnostic_dsn(bounce, bounce_info, 235 DSN_NOTIFY_FAILURE) > 0) { 236 bounce_original(bounce, bounce_info, dsn_ret ? 237 dsn_ret : DSN_RET_FULL); 238 bounce_status = post_mail_fclose(bounce); 239 if (bounce_status == 0) 240 msg_info("%s: sender non-delivery notification: %s", 241 queue_id, STR(new_id)); 242 } else { 243 /* No applicable recipients found - cancel this notice. */ 244 (void) vstream_fclose(bounce); 245 if (count == 0) 246 bounce_status = 0; 247 } 248 } 249 250 /* 251 * Optionally, send a postmaster notice, subject to notify_classes 252 * restrictions. 253 * 254 * This postmaster notice is not critical, so if it fails don't 255 * retransmit the bounce that we just generated, just log a warning. 256 */ 257 #define SEND_POSTMASTER_SINGLE_BOUNCE_NOTICE (notify_mask & MAIL_ERROR_BOUNCE) 258 259 if (bounce_status == 0 && SEND_POSTMASTER_SINGLE_BOUNCE_NOTICE 260 && strcasecmp(recipient, mail_addr_double_bounce()) != 0) { 261 262 /* 263 * Send the text with reason for the bounce, and the headers of 264 * the original message. Don't bother sending the boiler-plate 265 * text. This postmaster notice is not critical, so if it fails 266 * don't retransmit the bounce that we just generated, just log a 267 * warning. 268 */ 269 postmaster = var_bounce_rcpt; 270 if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(), 271 postmaster, 272 INT_FILT_MASK_BOUNCE, 273 NULL_TRACE_FLAGS, 274 new_id)) != 0) { 275 count = -1; 276 if (bounce_header(bounce, bounce_info, postmaster, 277 POSTMASTER_COPY) == 0 278 && (count = bounce_diagnostic_log(bounce, bounce_info, 279 DSN_NOTIFY_OVERRIDE)) > 0 280 && bounce_header_dsn(bounce, bounce_info) == 0 281 && bounce_diagnostic_dsn(bounce, bounce_info, 282 DSN_NOTIFY_OVERRIDE) > 0) { 283 bounce_original(bounce, bounce_info, DSN_RET_HDRS); 284 postmaster_status = post_mail_fclose(bounce); 285 if (postmaster_status == 0) 286 msg_info("%s: postmaster non-delivery notification: %s", 287 queue_id, STR(new_id)); 288 } else { 289 /* No applicable recipients found - cancel this notice. */ 290 (void) vstream_fclose(bounce); 291 if (count == 0) 292 postmaster_status = 0; 293 } 294 } 295 if (postmaster_status) 296 msg_warn("%s: postmaster notice failed while bouncing to %s", 297 queue_id, recipient); 298 } 299 } 300 301 /* 302 * Optionally, delete the recipients from the queue file. 303 */ 304 if (bounce_status == 0 && (flags & BOUNCE_FLAG_DELRCPT)) 305 bounce_delrcpt(bounce_info); 306 307 /* 308 * Examine the completion status. Delete the bounce log file only when 309 * the bounce was posted successfully, and only if we are bouncing for 310 * real, not just warning. 311 */ 312 if (bounce_status == 0 && mail_queue_remove(service, queue_id) 313 && errno != ENOENT) 314 msg_fatal("remove %s %s: %m", service, queue_id); 315 316 /* 317 * Cleanup. 318 */ 319 bounce_mail_free(bounce_info); 320 vstring_free(new_id); 321 322 return (bounce_status); 323 } 324