/*++ /* NAME /* bounce_append_service 3 /* SUMMARY /* append record to bounce log, server side /* SYNOPSIS /* #include "bounce_service.h" /* /* int bounce_append_service(queue_id, recipient, why) /* char *queue_id; /* char *recipient; /* char *why; /* DESCRIPTION /* This module implements the server side of the bounce_append() /* (append bounce log) request. This routine either succeeds or /* it raises a fatal error. /* DIAGNOSTICS /* Fatal errors: all file access errors; memory allocation errors. /* 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 <unistd.h> #include <fcntl.h> #include <errno.h> #include <ctype.h> #include <string.h> /* Utility library. */ #include <msg.h> #include <vstring.h> #include <vstream.h> #include <stringops.h> /* Global library. */ #include <mail_queue.h> #include <quote_822_local.h> #include <deliver_flock.h> /* Application-specific. */ #include "bounce_service.h" /* bounce_append_service - append bounce log */ int bounce_append_service(char *service, char *queue_id, char *recipient, char *why) { VSTRING *in_buf = vstring_alloc(100); VSTRING *out_buf = vstring_alloc(100); VSTREAM *log; long orig_length; /* * This code is paranoid for a good reason. Once the bounce service takes * responsibility, the mail system will make no further attempts to * deliver this recipient. Whenever file access fails, assume that the * system is under stress or that something has been mis-configured, and * force a backoff by raising a fatal run-time error. */ log = mail_queue_open(service, queue_id, O_WRONLY | O_APPEND | O_CREAT, 0600); if (log == 0) msg_fatal("open file %s %s: %m", service, queue_id); /* * Lock out other processes to avoid truncating someone else's data in * case of trouble. */ if (deliver_flock(vstream_fileno(log), INTERNAL_LOCK, (VSTRING *) 0) < 0) msg_fatal("lock file %s %s: %m", service, queue_id); /* * Now, go for it. Append a record. Truncate the log to the original * length when the append operation fails. We use the plain stream-lf * file format because we do not need anything more complicated. As a * benefit, we can still recover some data when the file is a little * garbled. * * XXX addresses in defer logfiles are in printable quoted form, while * addresses in message envelope records are in raw unquoted form. This * may change once we replace the present ad-hoc bounce/defer logfile * format by one that is transparent for control etc. characters. See * also: showq/showq.c. */ if ((orig_length = vstream_fseek(log, 0L, SEEK_END)) < 0) msg_fatal("seek file %s %s: %m", service, queue_id); if (*recipient) vstream_fprintf(log, "<%s>: ", printable(vstring_str(quote_822_local(in_buf, recipient)), '?')); else vstream_fprintf(log, "<>: "); vstream_fputs(printable(why, '?'), log); vstream_fputs("\n\n", log); if (vstream_fflush(log) != 0 || fsync(vstream_fileno(log)) < 0) { #ifndef NO_TRUNCATE if (ftruncate(vstream_fileno(log), (off_t) orig_length) < 0) msg_fatal("truncate file %s %s: %m", service, queue_id); #endif msg_fatal("append file %s %s: %m", service, queue_id); } /* * Darn. If closing the log detects a problem, the only way to undo the * damage is to open the log once more, and to truncate the log to the * original length. But, this could happen only when the log is kept on a * remote file system, and that is not recommended practice anyway. */ if (vstream_fclose(log) != 0) msg_warn("append file %s %s: %m", service, queue_id); vstring_free(in_buf); vstring_free(out_buf); return (0); }