/* assuan-inquire.c - handle inquire stuff
* Copyright (C) 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
*
* This file is part of Assuan.
*
* Assuan is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Assuan 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "assuan-defs.h"
#define digitp(a) ((a) >= '0' && (a) <= '9')
#define xtoi_1(p) (*(p) <= '9'? (*(p)- '0'): \
*(p) <= 'F'? (*(p)-'A'+10):(*(p)-'a'+10))
#define xtoi_2(p) ((xtoi_1(p) * 16) + xtoi_1((p)+1))
struct membuf
{
size_t len;
size_t size;
char *buf;
int out_of_core;
int too_large;
size_t maxlen;
};
/* A simple implementation of a dynamic buffer. Use init_membuf() to
create a buffer, put_membuf to append bytes and get_membuf to
release and return the buffer. Allocation errors are detected but
only returned at the final get_membuf(), this helps not to clutter
the code with out of core checks. */
static void
init_membuf (struct membuf *mb, int initiallen, size_t maxlen)
{
mb->len = 0;
mb->size = initiallen;
mb->out_of_core = 0;
mb->too_large = 0;
mb->maxlen = maxlen;
/* we need to allocate one byte more for get_membuf */
mb->buf = xtrymalloc (initiallen+1);
if (!mb->buf)
mb->out_of_core = 1;
}
static void
put_membuf (struct membuf *mb, const void *buf, size_t len)
{
if (mb->out_of_core || mb->too_large)
return;
if (mb->maxlen && mb->len + len > mb->maxlen)
{
mb->too_large = 1;
return;
}
if (mb->len + len >= mb->size)
{
char *p;
mb->size += len + 1024;
/* we need to allocate one byte more for get_membuf */
p = xtryrealloc (mb->buf, mb->size+1);
if (!p)
{
mb->out_of_core = 1;
return;
}
mb->buf = p;
}
memcpy (mb->buf + mb->len, buf, len);
mb->len += len;
}
static void *
get_membuf (struct membuf *mb, size_t *len)
{
char *p;
if (mb->out_of_core || mb->too_large)
{
xfree (mb->buf);
mb->buf = NULL;
return NULL;
}
mb->buf[mb->len] = 0; /* there is enough space for the hidden eos */
p = mb->buf;
*len = mb->len;
mb->buf = NULL;
mb->out_of_core = 1; /* don't allow a reuse */
return p;
}
static void
free_membuf (struct membuf *mb)
{
xfree (mb->buf);
mb->buf = NULL;
}
/**
* assuan_inquire:
* @ctx: An assuan context
* @keyword: The keyword used for the inquire
* @r_buffer: Returns an allocated buffer
* @r_length: Returns the length of this buffer
* @maxlen: If not 0, the size limit of the inquired data.
*
* A Server may use this to Send an inquire. r_buffer, r_length and
* maxlen may all be NULL/0 to indicate that no real data is expected.
*
* Return value: 0 on success or an ASSUAN error code
**/
assuan_error_t
assuan_inquire (assuan_context_t ctx, const char *keyword,
unsigned char **r_buffer, size_t *r_length, size_t maxlen)
{
assuan_error_t rc;
struct membuf mb;
char cmdbuf[LINELENGTH-10]; /* (10 = strlen ("INQUIRE ")+CR,LF) */
unsigned char *line, *p;
int linelen;
int nodataexpected;
if (!ctx || !keyword || (10 + strlen (keyword) >= sizeof (cmdbuf)))
return _assuan_error (ASSUAN_Invalid_Value);
nodataexpected = !r_buffer && !r_length && !maxlen;
if (!nodataexpected && (!r_buffer || !r_length))
return _assuan_error (ASSUAN_Invalid_Value);
if (!ctx->is_server)
return _assuan_error (ASSUAN_Not_A_Server);
if (ctx->in_inquire)
return _assuan_error (ASSUAN_Nested_Commands);
ctx->in_inquire = 1;
if (nodataexpected)
memset (&mb, 0, sizeof mb); /* avoid compiler warnings */
else
init_membuf (&mb, maxlen? maxlen:1024, maxlen);
strcpy (stpcpy (cmdbuf, "INQUIRE "), keyword);
rc = assuan_write_line (ctx, cmdbuf);
if (rc)
goto leave;
for (;;)
{
do
{
rc = _assuan_read_line (ctx);
if (rc)
goto leave;
line = (unsigned char *) ctx->inbound.line;
linelen = ctx->inbound.linelen;
}
while (*line == '#' || !linelen);
if (line[0] == 'E' && line[1] == 'N' && line[2] == 'D'
&& (!line[3] || line[3] == ' '))
break; /* END command received*/
if (line[0] == 'C' && line[1] == 'A' && line[2] == 'N')
{
rc = _assuan_error (ASSUAN_Canceled);
goto leave;
}
if (line[0] != 'D' || line[1] != ' ' || nodataexpected)
{
rc = _assuan_error (ASSUAN_Unexpected_Command);
goto leave;
}
if (linelen < 3)
continue;
line += 2;
linelen -= 2;
p = line;
while (linelen)
{
for (;linelen && *p != '%'; linelen--, p++)
;
put_membuf (&mb, line, p-line);
if (linelen > 2)
{ /* handle escaping */
unsigned char tmp[1];
p++;
*tmp = xtoi_2 (p);
p += 2;
linelen -= 3;
put_membuf (&mb, tmp, 1);
}
line = p;
}
if (mb.too_large)
{
rc = _assuan_error (ASSUAN_Too_Much_Data);
goto leave;
}
}
if (!nodataexpected)
{
*r_buffer = get_membuf (&mb, r_length);
if (!*r_buffer)
rc = _assuan_error (ASSUAN_Out_Of_Core);
}
leave:
if (!nodataexpected)
free_membuf (&mb);
ctx->in_inquire = 0;
return rc;
}
void
_assuan_inquire_release (assuan_context_t ctx)
{
if (ctx->in_inquire)
{
if (ctx->inquire_membuf)
{
free_membuf (ctx->inquire_membuf);
free (ctx->inquire_membuf);
}
ctx->in_inquire = 0;
}
}
int
_assuan_inquire_ext_cb (assuan_context_t ctx)
{
int rc;
unsigned char *line;
int linelen;
struct membuf *mb;
unsigned char *p;
line = (unsigned char *) ctx->inbound.line;
linelen = ctx->inbound.linelen;
mb = ctx->inquire_membuf;
if (line[0] == 'C' && line[1] == 'A' && line[2] == 'N')
{
rc = _assuan_error (ASSUAN_Canceled);
goto leave;
}
if (line[0] == 'E' && line[1] == 'N' && line[2] == 'D'
&& (!line[3] || line[3] == ' '))
{
rc = 0;
goto leave;
}
if (line[0] != 'D' || line[1] != ' ' || mb == NULL)
{
rc = _assuan_error (ASSUAN_Unexpected_Command);
goto leave;
}
if (linelen < 3)
return 0;
line += 2;
linelen -= 2;
p = line;
while (linelen)
{
for (;linelen && *p != '%'; linelen--, p++)
;
put_membuf (mb, line, p-line);
if (linelen > 2)
{ /* handle escaping */
unsigned char tmp[1];
p++;
*tmp = xtoi_2 (p);
p += 2;
linelen -= 3;
put_membuf (mb, tmp, 1);
}
line = p;
}
if (mb->too_large)
{
rc = _assuan_error (ASSUAN_Too_Much_Data);
goto leave;
}
return 0;
leave:
{
size_t buf_len = 0;
unsigned char *buf = NULL;
if (mb)
{
buf = get_membuf (mb, &buf_len);
if (!buf)
rc = _assuan_error (ASSUAN_Out_Of_Core);
free_membuf (mb);
free (mb);
ctx->inquire_membuf = NULL;
}
ctx->in_inquire = 0;
rc = (ctx->inquire_cb) (ctx->inquire_cb_data, rc, buf, buf_len);
}
return rc;
}
/**
* assuan_inquire_ext:
* @ctx: An assuan context
* @keyword: The keyword used for the inquire
* @maxlen: If not 0, the size limit of the inquired data.
* @cb: A callback handler which is invoked after the operation completed.
* @cb_data: A user-provided value passed to the callback handler.
*
* A Server may use this to Send an inquire. r_buffer, r_length and
* maxlen may all be NULL/0 to indicate that no real data is expected.
* When this function returns,
*
* Return value: 0 on success or an ASSUAN error code
**/
assuan_error_t
assuan_inquire_ext (assuan_context_t ctx, const char *keyword, size_t maxlen,
int (*cb) (void *cb_data, int rc, unsigned char *buf,
size_t len),
void *cb_data)
{
assuan_error_t rc;
struct membuf *mb = NULL;
char cmdbuf[LINELENGTH-10]; /* (10 = strlen ("INQUIRE ")+CR,LF) */
if (!ctx || !keyword || (10 + strlen (keyword) >= sizeof (cmdbuf)))
return _assuan_error (ASSUAN_Invalid_Value);
if (!ctx->is_server)
return _assuan_error (ASSUAN_Not_A_Server);
if (ctx->in_inquire)
return _assuan_error (ASSUAN_Nested_Commands);
mb = malloc (sizeof (struct membuf));
if (!mb)
return _assuan_error (ASSUAN_Out_Of_Core);
init_membuf (mb, maxlen ? maxlen : 1024, maxlen);
strcpy (stpcpy (cmdbuf, "INQUIRE "), keyword);
rc = assuan_write_line (ctx, cmdbuf);
if (rc)
{
free_membuf (mb);
free (mb);
return rc;
}
ctx->in_inquire = 1;
/* Set up the continuation. */
ctx->inquire_cb = cb;
ctx->inquire_cb_data = cb_data;
ctx->inquire_membuf = mb;
return 0;
}