/*++ /* NAME /* bounce_notify_service 3 /* SUMMARY /* send non-delivery report to sender, server side /* SYNOPSIS /* #include "bounce_service.h" /* /* int bounce_notify_service(flags, queue_name, queue_id, encoding, /* sender) /* int flags; /* char *queue_name; /* char *queue_id; /* char *encoding; /* char *sender; /* int flush; /* DESCRIPTION /* This module implements the server side of the bounce_notify() /* (send bounce message) request. The logfile is removed after a /* warning is posted. /* /* When a message bounces, a full copy is sent to the originator, /* and an optional copy of the diagnostics with message headers is /* sent to the postmaster. The result is non-zero when the operation /* should be tried again. /* /* When a bounce is sent, the sender address is the empty /* address. When a bounce bounces, an optional double bounce /* with the entire undeliverable mail is sent to the postmaster, /* with as sender address the double bounce address. /* DIAGNOSTICS /* Fatal error: error opening existing file. Warnings: corrupt /* message file. A corrupt message is saved to the "corrupt" /* queue for further inspection. /* BUGS /* SEE ALSO /* bounce(3) basic bounce service client interface /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ /* System library. */ #include <sys_defs.h> #include <fcntl.h> #include <errno.h> #include <string.h> #include <ctype.h> #ifdef STRCASECMP_IN_STRINGS_H #include <strings.h> #endif /* Utility library. */ #include <msg.h> #include <vstream.h> #include <name_mask.h> /* Global library. */ #include <mail_params.h> #include <mail_queue.h> #include <post_mail.h> #include <mail_addr.h> #include <mail_error.h> #include <bounce.h> /* Application-specific. */ #include "bounce_service.h" #define STR vstring_str /* bounce_notify_service - send a bounce */ int bounce_notify_service(int flags, char *service, char *queue_name, char *queue_id, char *encoding, char *recipient) { BOUNCE_INFO *bounce_info; int bounce_status = 1; int postmaster_status = 1; VSTREAM *bounce; int notify_mask = name_mask(VAR_NOTIFY_CLASSES, mail_error_masks, var_notify_classes); char *postmaster; /* * Initialize. Open queue file, bounce log, etc. */ bounce_info = bounce_mail_init(service, queue_name, queue_id, encoding, BOUNCE_MSG_FAIL); #define NULL_SENDER MAIL_ADDR_EMPTY /* special address */ #define NULL_TRACE_FLAGS 0 #define BOUNCE_HEADERS 1 #define BOUNCE_ALL 0 /* * The choice of sender address depends on the recipient address. For a * single bounce (a non-delivery notification to the message originator), * the sender address is the empty string. For a double bounce (typically * a failed single bounce, or a postmaster notification that was produced * by any of the mail processes) the sender address is defined by the * var_double_bounce_sender configuration variable. When a double bounce * cannot be delivered, the queue manager blackholes the resulting triple * bounce message. */ /* * Double bounce failed. Never send a triple bounce. * * However, this does not prevent double bounces from bouncing on other * systems. In order to cope with this, either the queue manager must * recognize the double-bounce recipient address and discard mail, or * every delivery agent must recognize the double-bounce sender address * and substitute something else so mail does not come back at us. */ if (strcasecmp(recipient, mail_addr_double_bounce()) == 0) { msg_warn("%s: undeliverable postmaster notification discarded", queue_id); bounce_status = 0; } /* * Single bounce failed. Optionally send a double bounce to postmaster. */ #define ANY_BOUNCE (MAIL_ERROR_2BOUNCE | MAIL_ERROR_BOUNCE) #define SKIP_IF_BOUNCE ((notify_mask & ANY_BOUNCE) == 0) else if (*recipient == 0) { if (SKIP_IF_BOUNCE) { bounce_status = 0; } else { postmaster = var_2bounce_rcpt; if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(), postmaster, CLEANUP_FLAG_MASK_INTERNAL, NULL_TRACE_FLAGS)) != 0) { /* * Double bounce to Postmaster. This is the last opportunity * for this message to be delivered. Send the text with * reason for the bounce, and the headers of the original * message. Don't bother sending the boiler-plate text. */ if (!bounce_header(bounce, bounce_info, postmaster) && bounce_diagnostic_log(bounce, bounce_info) == 0 && bounce_header_dsn(bounce, bounce_info) == 0 && bounce_diagnostic_dsn(bounce, bounce_info) == 0) bounce_original(bounce, bounce_info, BOUNCE_ALL); bounce_status = post_mail_fclose(bounce); } } } /* * Non-bounce failed. Send a single bounce. */ else { if ((bounce = post_mail_fopen_nowait(NULL_SENDER, recipient, CLEANUP_FLAG_MASK_INTERNAL, NULL_TRACE_FLAGS)) != 0) { /* * Send the bounce message header, some boilerplate text that * pretends that we are a polite mail system, the text with * reason for the bounce, and a copy of the original message. */ if (bounce_header(bounce, bounce_info, recipient) == 0 && bounce_boilerplate(bounce, bounce_info) == 0 && bounce_diagnostic_log(bounce, bounce_info) == 0 && bounce_header_dsn(bounce, bounce_info) == 0 && bounce_diagnostic_dsn(bounce, bounce_info) == 0) bounce_original(bounce, bounce_info, BOUNCE_ALL); bounce_status = post_mail_fclose(bounce); } /* * Optionally, send a postmaster notice. * * This postmaster notice is not critical, so if it fails don't * retransmit the bounce that we just generated, just log a warning. */ #define WANT_IF_BOUNCE ((notify_mask & MAIL_ERROR_BOUNCE)) if (bounce_status == 0 && (WANT_IF_BOUNCE) && strcasecmp(recipient, mail_addr_double_bounce()) != 0) { /* * Send the text with reason for the bounce, and the headers of * the original message. Don't bother sending the boiler-plate * text. This postmaster notice is not critical, so if it fails * don't retransmit the bounce that we just generated, just log a * warning. */ postmaster = var_bounce_rcpt; if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(), postmaster, CLEANUP_FLAG_MASK_INTERNAL, NULL_TRACE_FLAGS)) != 0) { if (bounce_header(bounce, bounce_info, postmaster) == 0 && bounce_diagnostic_log(bounce, bounce_info) == 0 && bounce_header_dsn(bounce, bounce_info) == 0 && bounce_diagnostic_dsn(bounce, bounce_info) == 0) bounce_original(bounce, bounce_info, BOUNCE_HEADERS); postmaster_status = post_mail_fclose(bounce); } if (postmaster_status) msg_warn("postmaster notice failed while bouncing to %s", recipient); } } /* * Optionally, delete the recipients from the queue file. */ if (bounce_status == 0 && (flags & BOUNCE_FLAG_DELRCPT)) bounce_delrcpt(bounce_info); /* * Examine the completion status. Delete the bounce log file only when * the bounce was posted successfully, and only if we are bouncing for * real, not just warning. */ if (bounce_status == 0 && mail_queue_remove(service, queue_id) && errno != ENOENT) msg_fatal("remove %s %s: %m", service, queue_id); /* * Cleanup. */ bounce_mail_free(bounce_info); return (bounce_status); }