NetBSD/gnu/dist/postfix/global/mail_copy.c
2000-05-13 14:50:45 +00:00

219 lines
6.5 KiB
C

/*++
/* NAME
/* mail_copy 3
/* SUMMARY
/* copy message with extreme prejudice
/* SYNOPSIS
/* #include <mail_copy.h>
/*
/* int mail_copy(sender, delivered, src, dst, flags, why)
/* const char *sender;
/* const char *delivered;
/* VSTREAM *src;
/* VSTREAM *dst;
/* int flags;
/* VSTRING *why;
/* DESCRIPTION
/* mail_copy() copies a mail message from record stream to stream-lf
/* stream, and attempts to detect all possible I/O errors.
/*
/* Arguments:
/* .IP sender
/* The sender envelope address.
/* .IP delivered
/* Null pointer or delivered-to: header address.
/* .IP src
/* The source record stream, positioned at the beginning of the
/* message contents.
/* .IP dst
/* The destination byte stream (in stream-lf format). If the message
/* ends in an incomplete line, a newline character is appended to
/* the output.
/* .IP flags
/* The binary OR of zero or more of the following:
/* .RS
/* .IP MAIL_COPY_QUOTE
/* Prepend a `>' character to lines beginning with `From '.
/* .IP MAIL_COPY_DOT
/* Prepend a `.' character to lines beginning with `.'.
/* .IP MAIL_COPY_TOFILE
/* On systems that support this, use fsync() to flush the
/* data to stable storage, and truncate the destination
/* file to its original length in case of problems.
/* .IP MAIL_COPY_FROM
/* Prepend a UNIX-style From_ line to the message, and append
/* an empty line to the end of the message.
/* .IP MAIL_COPY_DELIVERED
/* Prepend a Delivered-To: header with the name of the
/* \fIdelivered\fR attribute.
/* .IP MAIL_COPY_RETURN_PATH
/* Prepend a Return-Path: header with the value of the
/* \fIsender\fR attribute.
/* .RE
/* The manifest constant MAIL_COPY_MBOX is a convenient shorthand for
/* all MAIL_COPY_XXX options that are appropriate for mailbox delivery.
/* Use MAIL_COPY_NONE to copy a message without any options enabled.
/* .IP why
/* A null pointer, or storage for the reason of failure.
/* DIAGNOSTICS
/* A non-zero result means the operation failed. Warnings: corrupt
/* message file. A corrupt message is marked as corrupt.
/* SEE ALSO
/* mark_corrupt(3), mark queue file as corrupted.
/* 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 <string.h>
#include <unistd.h>
#include <time.h>
/* Utility library. */
#include <msg.h>
#include <htable.h>
#include <vstream.h>
#include <vstring.h>
#include <vstring_vstream.h>
#include <stringops.h>
/* Global library. */
#include "quote_822_local.h"
#include "record.h"
#include "rec_type.h"
#include "mail_queue.h"
#include "mail_addr.h"
#include "mail_copy.h"
#include "mark_corrupt.h"
/* mail_copy - copy message with extreme prejudice */
int mail_copy(const char *sender, const char *delivered,
VSTREAM *src, VSTREAM *dst,
int flags, VSTRING *why)
{
char *myname = "mail_copy";
VSTRING *buf;
char *bp;
long orig_length;
int read_error;
int write_error;
int corrupt_error = 0;
time_t now;
int type;
int prev_type;
/*
* Initialize.
*/
#ifndef NO_TRUNCATE
if ((flags & MAIL_COPY_TOFILE) != 0)
if ((orig_length = vstream_fseek(dst, 0L, SEEK_END)) < 0)
msg_fatal("seek file %s: %m", VSTREAM_PATH(dst));
#endif
buf = vstring_alloc(100);
/*
* Prepend a bunch of headers to the message.
*/
if (flags & (MAIL_COPY_FROM | MAIL_COPY_RETURN_PATH)) {
if (sender == 0)
msg_panic("%s: null sender", myname);
quote_822_local(buf, sender);
if (flags & MAIL_COPY_FROM) {
time(&now);
vstream_fprintf(dst, "From %s %s", *sender == 0 ?
MAIL_ADDR_MAIL_DAEMON :
vstring_str(buf),
asctime(localtime(&now)));
}
if (flags & MAIL_COPY_RETURN_PATH) {
vstream_fprintf(dst, "Return-Path: <%s>\n",
*sender ? vstring_str(buf) : "");
}
}
if (flags & MAIL_COPY_DELIVERED) {
if (delivered == 0)
msg_panic("%s: null delivered", myname);
quote_822_local(buf, delivered);
vstream_fprintf(dst, "Delivered-To: %s\n", lowercase(vstring_str(buf)));
}
/*
* Copy the message. Escape lines that could be confused with the ugly
* From_ line. Make sure that there is a blank line at the end of the
* message so that the next ugly From_ can be found by mail reading
* software.
*
* XXX Rely on the front-end services to enforce record size limits.
*/
#define VSTREAM_FWRITE_BUF(s,b) \
vstream_fwrite((s),vstring_str(b),VSTRING_LEN(b))
prev_type = REC_TYPE_NORM;
while ((type = rec_get(src, buf, 0)) > 0) {
if (type != REC_TYPE_NORM && type != REC_TYPE_CONT)
break;
bp = vstring_str(buf);
if (prev_type == REC_TYPE_NORM) {
if ((flags & MAIL_COPY_QUOTE) && *bp == 'F' && !strncmp(bp, "From ", 5))
VSTREAM_PUTC('>', dst);
if ((flags & MAIL_COPY_DOT) && *bp == '.')
VSTREAM_PUTC('.', dst);
}
if (VSTRING_LEN(buf) && VSTREAM_FWRITE_BUF(dst, buf) != VSTRING_LEN(buf))
break;
if (type == REC_TYPE_NORM && VSTREAM_PUTC('\n', dst) == VSTREAM_EOF)
break;
prev_type = type;
}
if (vstream_ferror(dst) == 0) {
if (type != REC_TYPE_XTRA)
corrupt_error = mark_corrupt(src);
if (prev_type != REC_TYPE_NORM)
VSTREAM_PUTC('\n', dst);
if (flags & MAIL_COPY_FROM)
VSTREAM_PUTC('\n', dst);
}
vstring_free(buf);
/*
* Make sure we read and wrote all. Truncate the file to its original
* length when the delivery failed. POSIX does not require ftruncate(),
* so we may have a portability problem. Note that fclose() may fail even
* while fflush and fsync() succeed. Think of remote file systems such as
* AFS that copy the file back to the server upon close. Oh well, no
* point optimizing the error case. XXX On systems that use flock()
* locking, we must truncate the file file before closing it (and losing
* the exclusive lock).
*/
read_error = vstream_ferror(src);
write_error = vstream_fflush(dst);
#ifdef HAS_FSYNC
if ((flags & MAIL_COPY_TOFILE) != 0)
write_error |= fsync(vstream_fileno(dst));
#endif
#ifndef NO_TRUNCATE
if ((flags & MAIL_COPY_TOFILE) != 0)
if (read_error || write_error)
ftruncate(vstream_fileno(dst), (off_t) orig_length);
#endif
write_error |= vstream_fclose(dst);
if (why && read_error)
vstring_sprintf(why, "error reading message: %m");
if (why && write_error)
vstring_sprintf(why, "error writing message: %m");
return (corrupt_error || read_error || write_error);
}