experimental, non-working imap implementation

svn path=/trunk/; revision=22061

1 files changed, 761 insertions, 0 deletions

diff --git a/camel/providers/imapp/camel-imapp-stream.c b/camel/providers/imapp/camel-imapp-stream.c
new file mode 100644
index 0000000000..a9567bf4f8
--- /dev/null
+++ b/camel/providers/imapp/camel-imapp-stream.c
@@ -0,0 +1,761 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; fill-column: 160 -*-
+ *
+ * Author:
+ *  Michael Zucchi <notzed@ximian.com>
+ *
+ * Copyright 1999, 2000 Ximian, Inc. (www.ximian.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include <glib.h>
+
+#include <camel/camel-stream-mem.h>
+
+#include "camel-imapp-stream.h"
+#include "camel-imapp-exception.h"
+
+#define t(x) 
+#define io(x) x
+
+static void setup_table(void);
+
+static CamelObjectClass *parent_class = NULL;
+
+/* Returns the class for a CamelStream */
+#define CS_CLASS(so) CAMEL_IMAPP_STREAM_CLASS(CAMEL_OBJECT_GET_CLASS(so))
+
+#define CAMEL_IMAPP_STREAM_SIZE (4096)
+#define CAMEL_IMAPP_STREAM_TOKEN (4096) /* maximum token size */
+
+static int
+stream_fill(CamelIMAPPStream *is)
+{
+	int left = 0;
+
+	if (is->source) {
+		left = is->end - is->ptr;
+		memcpy(is->buf, is->ptr, left);
+		is->end = is->buf + left;
+		is->ptr = is->buf;
+		left = camel_stream_read(is->source, is->end, CAMEL_IMAPP_STREAM_SIZE - (is->end - is->buf));
+		if (left > 0) {
+			is->end += left;
+			io(printf("camel_imapp_read: buffer is '%.*s'\n", is->end - is->ptr, is->ptr));
+			return is->end - is->ptr;
+		} else {
+			io(printf("camel_imapp_read: -1\n"));
+			return -1;
+		}
+	}
+
+	printf("camel_imapp_read: 0\n");
+
+	return 0;
+}
+
+static ssize_t
+stream_read(CamelStream *stream, char *buffer, size_t n)
+{
+	CamelIMAPPStream *is = (CamelIMAPPStream *)stream;
+	ssize_t max;
+
+	if (is->literal == 0 || n == 0)
+		return 0;
+
+	max = is->end - is->ptr;
+	if (max > 0) {
+		max = MIN(max, is->literal);
+		max = MIN(max, n);
+		memcpy(buffer, is->ptr, max);
+		is->ptr += max;
+	} else {
+		max = MIN(is->literal, n);
+		max = camel_stream_read(is->source, buffer, max);
+		if (max <= 0)
+			return max;
+	}
+
+	is->literal -= max;
+	
+	return max;
+}
+
+static ssize_t
+stream_write(CamelStream *stream, const char *buffer, size_t n)
+{
+	CamelIMAPPStream *is = (CamelIMAPPStream *)stream;
+
+	return camel_stream_write(is->source, buffer, n);
+}
+
+static int
+stream_close(CamelStream *stream)
+{
+	/* nop? */
+	return 0;
+}
+
+static int
+stream_flush(CamelStream *stream)
+{
+	/* nop? */
+	return 0;
+}
+
+static gboolean
+stream_eos(CamelStream *stream)
+{
+	CamelIMAPPStream *is = (CamelIMAPPStream *)stream;
+
+	return is->literal == 0;
+}
+
+static int
+stream_reset(CamelStream *stream)
+{
+	/* nop?  reset literal mode? */
+	return 0;
+}
+
+static void
+camel_imapp_stream_class_init (CamelStreamClass *camel_imapp_stream_class)
+{
+	CamelStreamClass *camel_stream_class = (CamelStreamClass *)camel_imapp_stream_class;
+
+	parent_class = camel_type_get_global_classfuncs( CAMEL_OBJECT_TYPE );
+
+	/* virtual method definition */
+	camel_stream_class->read = stream_read;
+	camel_stream_class->write = stream_write;
+	camel_stream_class->close = stream_close;
+	camel_stream_class->flush = stream_flush;
+	camel_stream_class->eos = stream_eos;
+	camel_stream_class->reset = stream_reset;
+}
+
+static void
+camel_imapp_stream_init(CamelIMAPPStream *is, CamelIMAPPStreamClass *isclass)
+{
+	/* +1 is room for appending a 0 if we need to for a token */
+	is->ptr = is->end = is->buf = g_malloc(CAMEL_IMAPP_STREAM_SIZE+1);
+	is->tokenptr = is->tokenbuf = g_malloc(CAMEL_IMAPP_STREAM_SIZE+1);
+	is->tokenend = is->tokenbuf + CAMEL_IMAPP_STREAM_SIZE;
+}
+
+static void
+camel_imapp_stream_finalise(CamelIMAPPStream *is)
+{
+	g_free(is->buf);
+	if (is->source)
+		camel_object_unref((CamelObject *)is->source);
+}
+
+CamelType
+camel_imapp_stream_get_type (void)
+{
+	static CamelType camel_imapp_stream_type = CAMEL_INVALID_TYPE;
+
+	if (camel_imapp_stream_type == CAMEL_INVALID_TYPE) {
+		setup_table();
+		camel_imapp_stream_type = camel_type_register( camel_stream_get_type(),
+							    "CamelIMAPPStream",
+							    sizeof( CamelIMAPPStream ),
+							    sizeof( CamelIMAPPStreamClass ),
+							    (CamelObjectClassInitFunc) camel_imapp_stream_class_init,
+							    NULL,
+							    (CamelObjectInitFunc) camel_imapp_stream_init,
+							    (CamelObjectFinalizeFunc) camel_imapp_stream_finalise );
+	}
+
+	return camel_imapp_stream_type;
+}
+
+/**
+ * camel_imapp_stream_new:
+ *
+ * Returns a NULL stream.  A null stream is always at eof, and
+ * always returns success for all reads and writes.
+ *
+ * Return value: the stream
+ **/
+CamelStream *
+camel_imapp_stream_new(CamelStream *source)
+{
+	CamelIMAPPStream *is;
+
+	is = (CamelIMAPPStream *)camel_object_new(camel_imapp_stream_get_type ());
+	camel_object_ref((CamelObject *)source);
+	is->source = source;
+
+	return (CamelStream *)is;
+}
+
+
+/*
+ From rfc2060
+
+ATOM_CHAR       ::= <any CHAR except atom_specials>
+
+atom_specials   ::= "(" / ")" / "{" / SPACE / CTL / list_wildcards /
+                    quoted_specials
+
+CHAR            ::= <any 7-bit US-ASCII character except NUL,
+                     0x01 - 0x7f>
+
+CTL             ::= <any ASCII control character and DEL,
+                        0x00 - 0x1f, 0x7f>
+
+SPACE           ::= <ASCII SP, space, 0x20>
+
+list_wildcards  ::= "%" / "*"
+
+quoted_specials ::= <"> / "\"
+*/
+
+static unsigned char imap_specials[256] = {
+/* 00 */0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+/* 10 */0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+/* 20 */0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1,
+/* 30 */1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+/* 40 */1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+/* 50 */1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1,
+/* 60 */1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+/* 70 */1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+};
+
+#define imap_is_atom(c) ((imap_specials[(c)&0xff] & 0x01) != 0)
+#define imap_is_simple(c) ((imap_specials[(c)&0xff] & 0x02) != 0)
+#define imap_not_id(c) ((imap_specials[(c)&0xff] & 0x04) != 0)
+
+/* could be pregenerated, but this is cheap */
+static struct {
+	unsigned char *chars;
+	unsigned char mask;
+} is_masks[] = {
+	{ "\n*()[]+", 2 },
+	{ " \r\n()[]+", 4 },
+};
+
+static void setup_table(void)
+{
+	int i;
+	unsigned char *p, c;
+
+	for (i=0;i<(int)(sizeof(is_masks)/sizeof(is_masks[0]));i++) {
+		p = is_masks[i].chars;
+		while ((c = *p++))
+			imap_specials[c] |= is_masks[i].mask;
+	}
+}
+
+#if 0
+
+static int
+skip_ws(CamelIMAPPStream *is, unsigned char *pp, unsigned char *pe)
+{
+	register unsigned char c, *p;
+	unsigned char *e;
+
+	p = is->ptr;
+	e = is->end;
+
+	do {
+		while (p >= e ) {
+			is->ptr = p;
+			if (stream_fill(is) == IMAP_TOK_ERROR)
+				return IMAP_TOK_ERROR;
+			p = is->ptr;
+			e = is->end;
+		}
+		c = *p++;
+	} while (c == ' ' || c == '\r');
+
+	is->ptr = p;
+	is->end = e;
+
+	return c;
+}
+#endif
+
+/* FIXME: these should probably handle it themselves,
+   and get rid of the token interface? */
+int
+camel_imapp_stream_atom(CamelIMAPPStream *is, unsigned char **data, unsigned int *lenp)
+{
+	unsigned char *p, c;
+
+	/* this is only 'approximate' atom */
+	switch(camel_imapp_stream_token(is, data, lenp)) {
+	case IMAP_TOK_TOKEN:
+		p = *data;
+		while ((c = *p))
+			*p++ = toupper(c);
+	case IMAP_TOK_INT:
+		return 0;
+	case IMAP_TOK_ERROR:
+		return IMAP_TOK_ERROR;
+	default:
+		camel_exception_throw(1, "expecting atom");
+		printf("expecting atom!\n");
+		return IMAP_TOK_PROTOCOL;
+	}
+}
+
+/* gets an atom, a quoted_string, or a literal */
+int
+camel_imapp_stream_astring(CamelIMAPPStream *is, unsigned char **data)
+{
+	unsigned char *p, *start;
+	unsigned int len, inlen;
+
+	switch(camel_imapp_stream_token(is, data, &len)) {
+	case IMAP_TOK_TOKEN:
+	case IMAP_TOK_INT:
+	case IMAP_TOK_STRING:
+		return 0;
+	case IMAP_TOK_LITERAL:
+		/* FIXME: just grow buffer */
+		if (len >= CAMEL_IMAPP_STREAM_TOKEN) {
+			camel_exception_throw(1, "astring: literal too long");
+			printf("astring too long\n");
+			return IMAP_TOK_PROTOCOL;
+		}
+		p = is->tokenptr;
+		camel_imapp_stream_set_literal(is, len);
+		do {
+			len = camel_imapp_stream_getl(is, &start, &inlen);
+			if (len < 0)
+				return len;
+			memcpy(p, start, inlen);
+			p += inlen;
+		} while (len > 0);
+		*data = is->tokenptr;
+		return 0;
+	case IMAP_TOK_ERROR:
+		/* wont get unless no exception hanlder*/
+		return IMAP_TOK_ERROR;
+	default:
+		camel_exception_throw(1, "expecting astring");
+		printf("expecting astring!\n");
+		return IMAP_TOK_PROTOCOL;
+	}
+}
+
+/* check for NIL or (small) quoted_string or literal */
+int
+camel_imapp_stream_nstring(CamelIMAPPStream *is, unsigned char **data)
+{
+	unsigned char *p, *start;
+	unsigned int len, inlen;
+
+	switch(camel_imapp_stream_token(is, data, &len)) {
+	case IMAP_TOK_STRING:
+		return 0;
+	case IMAP_TOK_LITERAL:
+		/* FIXME: just grow buffer */
+		if (len >= CAMEL_IMAPP_STREAM_TOKEN) {
+			camel_exception_throw(1, "nstring: literal too long");
+			return IMAP_TOK_PROTOCOL;
+		}
+		p = is->tokenptr;
+		camel_imapp_stream_set_literal(is, len);
+		do {
+			len = camel_imapp_stream_getl(is, &start, &inlen);
+			if (len < 0)
+				return len;
+			memcpy(p, start, inlen);
+			p += inlen;
+		} while (len > 0);
+		*data = is->tokenptr;
+		return 0;
+	case IMAP_TOK_TOKEN:
+		p = *data;
+		if (toupper(p[0]) == 'N' && toupper(p[1]) == 'I' && toupper(p[2]) == 'L' && p[3] == 0) {
+			*data = NULL;
+			return 0;
+		}
+	default:
+		camel_exception_throw(1, "expecting nstring");
+		return IMAP_TOK_PROTOCOL;
+	case IMAP_TOK_ERROR:
+		/* we'll never get this unless there are no exception  handlers anyway */
+		return IMAP_TOK_ERROR;
+
+	}
+}
+
+/* parse an nstring as a stream */
+int
+camel_imapp_stream_nstring_stream(CamelIMAPPStream *is, CamelStream **stream)
+/* throws IO,PARSE exception */
+{
+	unsigned char *token;
+	unsigned int len;
+	int ret = 0;
+	CamelStream * volatile mem = NULL;
+
+	*stream = NULL;
+
+	CAMEL_TRY {
+		switch(camel_imapp_stream_token(is, &token, &len)) {
+		case IMAP_TOK_STRING:
+			mem = camel_stream_mem_new_with_buffer(token, len);
+			*stream = mem;
+			break;
+		case IMAP_TOK_LITERAL:
+			/* if len is big, we could automatically use a file backing */
+			camel_imapp_stream_set_literal(is, len);
+			mem = camel_stream_mem_new();
+			if (camel_stream_write_to_stream((CamelStream *)is, mem) == -1)
+				camel_exception_throw(1, "nstring: io error: %s", strerror(errno));
+			camel_stream_reset(mem);
+			*stream = mem;
+			break;
+		case IMAP_TOK_TOKEN:
+			if (toupper(token[0]) == 'N' && toupper(token[1]) == 'I' && toupper(token[2]) == 'L' && token[3] == 0) {
+				*stream = NULL;
+				break;
+			}
+		default:
+			ret = -1;
+			camel_exception_throw(1, "nstring: token not string");
+		}
+	} CAMEL_CATCH(ex) {
+		if (mem)
+			camel_object_unref((CamelObject *)mem);
+		camel_exception_throw_ex(ex);
+	} CAMEL_DONE;
+
+	/* never reaches here anyway */
+	return ret;
+}
+
+guint32
+camel_imapp_stream_number(CamelIMAPPStream *is)
+{
+	unsigned char *token;
+	unsigned int len;
+
+	if (camel_imapp_stream_token(is, &token, &len) != IMAP_TOK_INT) {
+		camel_exception_throw(1, "expecting number");
+		return 0;
+	}
+
+	return strtoul(token, 0, 10);
+}
+
+int
+camel_imapp_stream_text(CamelIMAPPStream *is, unsigned char **text)
+{
+	GByteArray *build = g_byte_array_new();
+	unsigned char *token;
+	unsigned int len;
+	int tok;
+
+	CAMEL_TRY {
+		while (is->unget > 0) {
+			switch (is->unget_tok) {
+			case IMAP_TOK_TOKEN:
+			case IMAP_TOK_STRING:
+			case IMAP_TOK_INT:
+				g_byte_array_append(build, is->unget_token, is->unget_len);
+				g_byte_array_append(build, " ", 1);
+			default: /* invalid, but we'll ignore */
+				break;
+			}
+			is->unget--;
+		}
+
+		do {
+			tok = camel_imapp_stream_gets(is, &token, &len);
+			if (tok < 0)
+				camel_exception_throw(1, "io error: %s", strerror(errno));
+			if (len)
+				g_byte_array_append(build, token, len);
+		} while (tok > 0);
+	} CAMEL_CATCH(ex) {
+		*text = NULL;
+		g_byte_array_free(build, TRUE);
+		camel_exception_throw_ex(ex);
+	} CAMEL_DONE;
+
+	g_byte_array_append(build, "", 1);
+	*text = build->data;
+	g_byte_array_free(build, FALSE);
+
+	return 0;
+}
+
+/* Get one token from the imap stream */
+camel_imapp_token_t
+/* throws IO,PARSE exception */
+camel_imapp_stream_token(CamelIMAPPStream *is, unsigned char **data, unsigned int *len)
+{
+	register unsigned char c, *p, *o, *oe;
+	unsigned char *e;
+	unsigned int literal;
+	int digits;
+
+	if (is->unget > 0) {
+		is->unget--;
+		*data = is->unget_token;
+		*len = is->unget_len;
+		/*printf("token UNGET '%c' %s\n", is->unget_tok, is->unget_token);*/
+		return is->unget_tok;
+	}
+
+	if (is->literal > 0)
+		g_warning("stream_token called with literal %d", is->literal);
+
+	p = is->ptr;
+	e = is->end;
+
+	/* skip whitespace/prefill buffer */
+	do {
+		while (p >= e ) {
+			is->ptr = p;
+			if (stream_fill(is) == IMAP_TOK_ERROR)
+				goto io_error;
+			p = is->ptr;
+			e = is->end;
+		}
+		c = *p++;
+	} while (c == ' ' || c == '\r');
+
+	/*strchr("\n*()[]+", c)*/
+	if (imap_is_simple(c)) {
+		is->ptr = p;
+		t(printf("token '%c'\n", c));
+		return c;
+	} else if (c == '{') {
+		literal = 0;
+		*data = p;
+		while (1) {
+			while (p < e) {
+				c = *p++;
+				if (isdigit(c) && literal < (UINT_MAX/10)) {
+					literal = literal * 10 + (c - '0');
+				} else if (c == '}') {
+					while (1) {
+						while (p < e) {
+							c = *p++;
+							if (c == '\n') {
+								*len = literal;
+								is->ptr = p;
+								is->literal = literal;
+								t(printf("token LITERAL %d\n", literal));
+								return IMAP_TOK_LITERAL;
+							}
+						}
+						is->ptr = p;
+						if (stream_fill(is) == IMAP_TOK_ERROR)
+							goto io_error;
+						p = is->ptr;
+						e = is->end;
+					}
+				} else {
+					if (isdigit(c))
+						printf("Protocol error: literal too big\n");
+					else
+						printf("Protocol error: literal contains invalid char %02x '%c'\n", c, isprint(c)?c:c);
+					goto protocol_error;
+				}
+			}
+			is->ptr = p;
+			if (stream_fill(is) == IMAP_TOK_ERROR)
+				goto io_error;
+			p = is->ptr;
+			e = is->end;
+		}
+	} else if (c == '"') {
+		o = is->tokenptr;
+		oe = is->tokenptr + CAMEL_IMAPP_STREAM_TOKEN - 1;
+		while (1) {
+			while (p < e) {
+				c = *p++;
+				if (c == '\\') {
+					while (p >= e) {
+						is->ptr = p;
+						if (stream_fill(is) == IMAP_TOK_ERROR)
+							goto io_error;
+						p = is->ptr;
+						e = is->end;
+					}
+					c = *p++;
+				} else if (c == '\"') {
+					is->ptr = p;
+					*o = 0;
+					*data = is->tokenbuf;
+					*len = o - is->tokenbuf;
+					t(printf("token STRING '%s'\n", is->tokenbuf));
+					return IMAP_TOK_STRING;
+				}
+
+				if (c == '\n' || c == '\r' || o>=oe) {
+					if (o >= oe)
+						printf("Protocol error: string too long\n");
+					else
+						printf("Protocol error: truncated string\n");
+					goto protocol_error;
+				} else {
+					*o++ = c;
+				}
+			}
+			is->ptr = p;
+			if (stream_fill(is) == IMAP_TOK_ERROR)
+				goto io_error;
+			p = is->ptr;
+			e = is->end;
+		}
+	} else {
+		o = is->tokenptr;
+		oe = is->tokenptr + CAMEL_IMAPP_STREAM_TOKEN - 1;
+		digits = isdigit(c);
+		*o++ = c;
+		while (1) {
+			while (p < e) {
+				c = *p++;
+				/*if (strchr(" \r\n*()[]+", c) != NULL) {*/
+				if (imap_not_id(c)) {
+					if (c == ' ' || c == '\r')
+						is->ptr = p;
+					else
+						is->ptr = p-1;
+					*o = 0;
+					*data = is->tokenbuf;
+					*len = o - is->tokenbuf;
+					t(printf("token TOKEN '%s'\n", is->tokenbuf));
+					return digits?IMAP_TOK_INT:IMAP_TOK_TOKEN;
+				} else if (o < oe) {
+					digits &= isdigit(c);
+					*o++ = c;
+				} else {
+					printf("Protocol error: token too long\n");
+					goto protocol_error;
+				}
+			}
+			is->ptr = p;
+			if (stream_fill(is) == IMAP_TOK_ERROR)
+				goto io_error;
+			p = is->ptr;
+			e = is->end;
+		}
+	}
+
+	/* Had an i/o erorr */
+io_error:
+	printf("Got io error\n");
+	camel_exception_throw(1, "io error");
+	return IMAP_TOK_ERROR;
+
+	/* Protocol error, skip until next lf? */
+protocol_error:
+	printf("Got protocol error\n");
+
+	if (c == '\n')
+		is->ptr = p-1;
+	else
+		is->ptr = p;
+
+	camel_exception_throw(1, "protocol error");
+	return IMAP_TOK_PROTOCOL;
+}
+
+void
+camel_imapp_stream_ungettoken(CamelIMAPPStream *is, camel_imapp_token_t tok, unsigned char *token, unsigned int len)
+{
+	/*printf("ungettoken: '%c' '%s'\n", tok, token);*/
+	is->unget_tok = tok;
+	is->unget_token = token;
+	is->unget_len = len;
+	is->unget++;
+}
+
+/* returns -1 on error, 0 if last lot of data, >0 if more remaining */
+int camel_imapp_stream_gets(CamelIMAPPStream *is, unsigned char **start, unsigned int *len)
+{
+	int max;
+	unsigned char *end;
+
+	*len = 0;
+
+	max = is->end - is->ptr;
+	if (max == 0) {
+		max = stream_fill(is);
+		if (max <= 0)
+			return max;
+	}
+
+	*start = is->ptr;
+	end = memchr(is->ptr, '\n', max);
+	if (end)
+		max = (end - is->ptr) + 1;
+	*start = is->ptr;
+	*len = max;
+	is->ptr += max;
+
+	return end == NULL?1:0;
+}
+
+void camel_imapp_stream_set_literal(CamelIMAPPStream *is, unsigned int literal)
+{
+	is->literal = literal;
+}
+
+/* returns -1 on erorr, 0 if last data, >0 if more data left */
+int camel_imapp_stream_getl(CamelIMAPPStream *is, unsigned char **start, unsigned int *len)
+{
+	int max;
+
+	*len = 0;
+
+	if (is->literal > 0) {
+		max = is->end - is->ptr;
+		if (max == 0) {
+			max = stream_fill(is);
+			if (max <= 0)
+				return max;
+		}
+
+		max = MIN(max, is->literal);
+		*start = is->ptr;
+		*len = max;
+		is->ptr += max;
+		is->literal -= max;
+	}
+
+	if (is->literal > 0)
+		return 1;
+
+	return 0;
+}