[Dovecot] Implementation of editheaders in dovecot

Konstantin Lepa konstantin.lepa at gmail.com
Fri Apr 3 13:12:38 EEST 2009


Hello.

I wrote the hook function for deliver. I want to add support of  
editheaders in the plug-in for dovecot. For this purpose I wrote the  
function rarules_get_stream. Remover of headrs works properly, but  
adding does not work. I took Timo Sirainen's advice from http://markmail.org/message/skb6arnll5gaopdr 
  . Do I use a correct way of creation of a message?

I give backtrace and a part of my code.

Thanks, Konstantin


uname -a:
FreeBSD bsdman.virtualworld.com 6.4-RELEASE FreeBSD 6.4-RELEASE #0:  
Wed Nov 26 11:43:51 UTC 2008     root at dessler.cse.buffalo.edu:/usr/obj/ 
usr/src/sys/GENERIC  i386

dovecot --version:
1.1.11

build:
  $ ./configure --localstatedir=/var --with-statedir=/var/db/dovecot -- 
without-shadow --enable-debug --with-ioloop=kqueue --disable-ipv6 -- 
with-gssapi --without-vpopmail --without-ldap --without-pgsql --with- 
mysql --without-sqlite --prefix=/usr/local --mandir=/usr/local/man -- 
infodir=/usr/local/info/ --build=i386-portbld-freebsd6.4

patches: in freebsd ports

(gdb) bt
#0  0x282f3a01 in memcpy () from /lib/libc.so.6
#1  0x080df555 in i_stream_concat_read_next (cstream=0x814aa00) at  
istream-concat.c:79
#2  0x080df784 in i_stream_concat_read (stream=0x814aa00) at istream- 
concat.c:136
#3  0x080de659 in i_stream_read (stream=0x814aa28) at istream.c:78
#4  0x080cd99a in i_stream_header_filter_read (stream=0x814e400) at  
istream-header-filter.c:322
#5  0x080de659 in i_stream_read (stream=0x814e428) at istream.c:78
#6  0x080dff26 in i_stream_crlf_read_common (cstream=0x814ad00) at  
istream-crlf.c:41
#7  0x080e01b3 in i_stream_crlf_read_lf (stream=0x814ad00) at istream- 
crlf.c:103
#8  0x080de659 in i_stream_read (stream=0x814ad28) at istream.c:78
#9  0x080e2611 in i_stream_tee_read (stream=0x814ae00) at istream- 
tee.c:122
#10 0x080de659 in i_stream_read (stream=0x814ae28) at istream.c:78
#11 0x080deea3 in i_stream_read_data (stream=0x814ae28,  
data_r=0xbfbfea88, size_r=0xbfbfea8c, threshold=1) at istream.c:322
#12 0x080d1744 in message_parser_read_more (ctx=0x8156468,  
block_r=0xbfbfea80, full_r=0xbfbfea27) at message-parser.c:117
#13 0x080d20ac in parse_next_body_to_eof (ctx=0x8156468,  
block_r=0xbfbfea80) at message-parser.c:411
#14 0x080d2ccf in message_parser_parse_next_block (ctx=0x8156468,  
block_r=0xbfbfea80) at message-parser.c:765
#15 0x080931d9 in index_mail_cache_parse_continue (_mail=0x8150060) at  
index-mail.c:1316
#16 0x0807838d in mbox_save_continue (_ctx=0x811bb00) at mbox-save.c:582
#17 0x080a05a8 in mailbox_save_continue (ctx=0x811bb00) at mail- 
storage.c:740
#18 0x0809d9df in mail_storage_copy (t=0x811b980, mail=0x8141860,  
flags=0, keywords=0x0, dest_mail=0x0) at mail-copy.c:33
#19 0x080a0632 in mailbox_copy (t=0x811b980, mail=0x8141860, flags=0,  
keywords=0x0, dest_mail=0x0) at mail-storage.c:763
#20 0x0805960d in deliver_save (namespaces=0x8121c68,  
storage_r=0xbfbfee14, mailbox=0x811a370 "Draft", mail=0x8141860,
     flags=0, keywords=0x0) at deliver.c:234
#21 0x2831fe8f in store_in (arg=0x811a370 "Draft", md=0xbfbfed00) at / 
home/pitman/work/rarules/src/actions.c:220
#22 0x2831f759 in rarules_execute_action  
(type=RARULES_ACTION_STORE_IN, arg=0x811a370 "Draft", md=0xbfbfed00)
     at /home/pitman/work/rarules/src/actions.c:57
#23 0x2831e70d in execute_actions (action=0x811a360, md=0xbfbfed00)  
at /home/pitman/work/rarules/src/rarules.c:98
#24 0x2831e692 in apply_rules (rule=0x811a320, md=0xbfbfed00) at /home/ 
pitman/work/rarules/src/rarules.c:80
#25 0x2831e56a in rarules_main (namespaces=0x8121c68,  
storage_r=0xbfbfee14, mail=0x8141860, db=0x8121000,
     destaddr=0xbfbfef62 "pitman at virtualworld.com", username=0x8113525  
"pitman at virtualworld.com", mailbox=0x80f2a19 "INBOX")
     at /home/pitman/work/rarules/src/rarules.c:52
#26 0x2831da37 in rarules_deliver_mail (namespaces=0x8121c68,  
storage_r=0xbfbfee14, mail=0x8141860,
     destaddr=0xbfbfef62 "pitman at virtualworld.com", mailbox=0x80f2a19  
"INBOX")
     at /home/pitman/work/rarules/src/rarules_plugin.c:126
#27 0x0805b69a in main (argc=3, argv=0xbfbfeeac) at deliver.c:1084

(gdb) f 1
#1  0x080df555 in i_stream_concat_read_next (cstream=0x814aa00) at  
istream-concat.c:79
79              memcpy(cstream->istream.w_buffer, data, data_size);

(gdb) p data
$4 = (const unsigned char *) 0x15 <Address 0x15 out of bounds>
(gdb) p data_size
$5 = 1

/////////////////////////////////////////My  
code/////////////////////////////////////////////////////////

static int rarules_get_stream(struct mail * mail, struct message_size  
* hdr_size,
                               struct message_size * body_size,
                               struct istream ** stream_r)
{
	struct rarules_mail * ra_mail = RARULES_MAIL_CONTEXT(mail);
	struct istream * stream = NULL;
	struct istream ** chunks = NULL;
	const unsigned int max_chunks = 4;

	unsigned int i = 0;
	unsigned int cnt = 0;
	unsigned int exclude_cnt = 0;
	unsigned int include_cnt = 0;

	int ret = 0;

#if 1
	{/* Test code */
		const char * str = "Subject";
		const char * str2 = "X-DSPAM: test value\n\n";

		array_append(&ra_mail->exclude_headers, &str, 1);
		array_append(&ra_mail->include_headers, &str2, 1);
	}
#endif

	DPRINT("Standard get_stream for mail storage format");
	ret = ra_mail->module_ctx.super.get_stream(mail, hdr_size, body_size,  
&stream);

	include_cnt = array_count(&ra_mail->include_headers);
	exclude_cnt = array_count(&ra_mail->exclude_headers);

	if ((!exclude_cnt && !include_cnt) || ret < 0) {
		*stream_r = stream;
		return ret;
	}

	DPRINT("Create message from chunks with new headers and skip excluded  
headers");
	chunks = t_new(struct istream *, max_chunks);
	chunks[cnt++] = header_filter(stream, &ra_mail->exclude_headers,  
exclude_cnt);
	if (include_cnt) {
		chunks[cnt++] = create_header_stream(&ra_mail->include_headers,  
include_cnt);
	}
	chunks[cnt++] = create_stream_for_msgbody(stream);
	chunks[cnt++] = NULL;

	*stream_r = i_stream_create_concat(chunks);

	DPRINT("Cleanup");

	array_clear(&ra_mail->include_headers);
	array_clear(&ra_mail->exclude_headers);

	for (i = 0; chunks[i] != NULL; ++i) { i_stream_unref(&chunks[i]); }
	i_stream_unref(&stream);

	DPRINTF("Func `%s' executed", __FUNCTION__);

	return ret;
}


inline static struct istream *
create_stream_for_msgbody(struct istream * stream)
{
	struct istream * tmp = stream;
	struct message_size hdr_size;
	struct message_size body_size;

	DPRINTF("Func `%s' called", __FUNCTION__);

	message_get_body_size(stream, &body_size, NULL);
	message_get_header_size(stream, &hdr_size, NULL);

	i_stream_seek(stream, hdr_size.physical_size);
	stream = i_stream_create_limit(stream, body_size.physical_size);

	i_stream_unref(&tmp);

	return stream;
}


inline static struct istream *
header_filter(struct istream * stream, ARRAY_TYPE(const_string) *  
headers_arr,
               unsigned int count)
{
	const char * const * headers = NULL;

	DPRINTF("Func `%s' called", __FUNCTION__);

	if (count) { headers = (const char **)array_idx(headers_arr, 0); }

	return i_stream_create_header_filter(stream,
					     HEADER_FILTER_EXCLUDE |
		                             HEADER_FILTER_NO_CR |
		                             HEADER_FILTER_HIDE_BODY,
					     headers,
					     count,
					     null_header_filter_callback,
					     NULL);
}


inline static struct istream *
create_header_stream(ARRAY_TYPE(const_string) * headers_arr, unsigned  
int count)
{
	unsigned int i = 0;
	struct istream  * result = NULL;
	struct istream ** chunks = NULL;
	const char * const * headers = NULL;

	DPRINTF("Func `%s' called", __FUNCTION__);
	i_assert(count != 0);

	headers = (const char **)array_idx(headers_arr, 0);

	DPRINT("Create streams for new included headers from headers");
	chunks = t_new(struct istream *, count + 1);
	for (i = 0; i < count; ++i) {
		struct istream * tmp = NULL;

		tmp = i_stream_create_from_data(headers[i], strlen(headers[i]));
		chunks[i] = i_stream_create_lf(tmp);
		i_stream_unref(&tmp);
	}
	chunks[count] = NULL;
	result = i_stream_create_concat(chunks);

	for (i = 0; chunks[i] != NULL; ++i) { i_stream_unref(&chunks[i]); }

	return result;
}



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