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gnupg/util/iobuf.c

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/* iobuf.c - file handling
* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG 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
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "memory.h"
#include "util.h"
#include "iobuf.h"
typedef struct {
FILE *fp; /* open file handle */
int print_only_name; /* flags indicating that fname is not a real file*/
char fname[1]; /* name of the file */
} file_filter_ctx_t ;
/* The first partial length header block must be of size 512
* to make it easier (and efficienter) we use a min. block size of 512
* for all chunks (but the last one) */
#define OP_MIN_PARTIAL_CHUNK 512
#define OP_MIN_PARTIAL_CHUNK_2POW 9
typedef struct {
int use;
size_t size;
size_t count;
int partial; /* 1 = partial header, 2 in last partial packet */
char *buffer; /* used for partial header */
size_t buflen; /* used size of buffer */
int first_c; /* of partial header (which is > 0)*/
int eof;
} block_filter_ctx_t;
static int underflow(IOBUF a);
static const char *get_real_fname( IOBUF a );
/****************
* Read data from a file into buf which has an allocated length of *LEN.
* return the number of read bytes in *LEN. OPAQUE is the FILE * of
* the stream. A is not used.
* control may be:
* IOBUFCTRL_INIT: called just before the function is linked into the
* list of function. This can be used to prepare internal
* data structures of the function.
* IOBUFCTRL_FREE: called just before the function is removed from the
* list of functions and can be used to release internal
* data structures or close a file etc.
* IOBUFCTRL_UNDERFLOW: called by iobuf_underflow to fill the buffer
* with new stuff. *RET_LEN is the available size of the
* buffer, and should be set to the number of bytes
* which were put into the buffer. The function
* returns 0 to indicate success, -1 on EOF and
* G10ERR_xxxxx for other errors.
*
* IOBUFCTRL_FLUSH: called by iobuf_flush() to write out the collected stuff.
* *RET_LAN is the number of bytes in BUF.
*
*/
static int
file_filter(void *opaque, int control, IOBUF chain, byte *buf, size_t *ret_len)
{
file_filter_ctx_t *a = opaque;
FILE *fp = a->fp;
size_t size = *ret_len;
size_t nbytes = 0;
int c, rc = 0;
char *p;
if( control == IOBUFCTRL_UNDERFLOW ) {
assert( size ); /* need a buffer */
for(; size; size-- ) {
if( (c=getc(fp)) == EOF ) {
if( ferror(fp) && errno != EPIPE ) {
log_error("%s: read error: %s\n",
a->fname, strerror(errno));
rc = G10ERR_READ_FILE;
}
else if( !nbytes )
rc = -1; /* okay: we can return EOF now. */
break;
}
buf[nbytes++] = c & 0xff;
}
*ret_len = nbytes;
}
else if( control == IOBUFCTRL_FLUSH ) {
for(p=buf; nbytes < size; nbytes++, p++ ) {
if( putc(*p, fp) == EOF ) {
log_error("%s: write error: %s\n",
a->fname, strerror(errno));
rc = G10ERR_WRITE_FILE;
break;
}
}
*ret_len = nbytes;
}
else if( control == IOBUFCTRL_INIT ) {
}
else if( control == IOBUFCTRL_DESC ) {
*(char**)buf = "file_filter";
}
else if( control == IOBUFCTRL_FREE ) {
if( fp != stdin && fp != stdout ) {
if( DBG_IOBUF )
log_debug("%s: close fd %d\n", a->fname, fileno(fp) );
fclose(fp);
}
fp = NULL;
m_free(a); /* we can free our context now */
}
return rc;
}
/****************
* This is used to implement the block write mode.
* Block reading is done on a byte by byte basis in readbyte(),
* without a filter
*/
static int
block_filter(void *opaque, int control, IOBUF chain, byte *buf, size_t *ret_len)
{
block_filter_ctx_t *a = opaque;
size_t size = *ret_len;
int c, rc = 0;
char *p;
if( control == IOBUFCTRL_UNDERFLOW ) {
size_t n=0;
p = buf;
assert( size ); /* need a buffer */
if( a->eof ) /* don't read any further */
rc = -1;
while( !rc && size ) {
if( !a->size ) { /* get the length bytes */
if( a->partial == 2 ) {
a->eof = 1;
if( !n )
rc = -1;
break;
}
else if( a->partial ) {
/* These OpenPGP introduced huffman encoded length
* bytes are really a mess :-( */
if( a->first_c ) {
c = a->first_c;
a->first_c = 0;
assert( c >= 224 && c < 255 );
}
else if( (c = iobuf_get(chain)) == -1 ) {
log_error("block_filter: 1st length byte missing\n");
rc = G10ERR_READ_FILE;
break;
}
if( c < 192 ) {
a->size = c;
a->partial = 2;
if( !a->size ) {
a->eof = 1;
if( !n )
rc = -1;
break;
}
}
else if( c < 224 ) {
a->size = (c - 192) * 256;
if( (c = iobuf_get(chain)) == -1 ) {
log_error("block_filter: 2nd length byte missing\n");
rc = G10ERR_READ_FILE;
break;
}
a->size += c + 192;
a->partial = 2;
if( !a->size ) {
a->eof = 1;
if( !n )
rc = -1;
break;
}
}
else if( c == 255 ) {
a->size = iobuf_get(chain) << 24;
a->size |= iobuf_get(chain) << 16;
a->size |= iobuf_get(chain) << 8;
if( (c = iobuf_get(chain)) == -1 ) {
log_error("block_filter: invalid 4 byte length\n");
rc = G10ERR_READ_FILE;
break;
}
a->size |= c;
}
else { /* next partial body length */
a->size = 1 << (c & 0x1f);
}
}
else { /* the gnupg partial length scheme - much better :-) */
c = iobuf_get(chain);
a->size = c << 8;
c = iobuf_get(chain);
a->size |= c;
if( c == -1 ) {
log_error("block_filter: error reading length info\n");
rc = G10ERR_READ_FILE;
}
if( !a->size ) {
a->eof = 1;
if( !n )
rc = -1;
break;
}
}
}
for(; !rc && size && a->size; size--, a->size-- ) {
if( (c=iobuf_get(chain)) == -1 ) {
log_error("block_filter %p: read error (size=%lu,a->size=%lu)\n",
a, (ulong)size, (ulong)a->size);
rc = G10ERR_READ_FILE;
}
else {
*p++ = c;
n++;
}
}
}
*ret_len = n;
}
else if( control == IOBUFCTRL_FLUSH ) {
if( a->partial ) { /* the complicated openpgp scheme */
size_t blen, n, nbytes = size + a->buflen;
assert( a->buflen <= OP_MIN_PARTIAL_CHUNK );
if( nbytes < OP_MIN_PARTIAL_CHUNK ) {
/* not enough to write a partial block out; so we store it*/
if( !a->buffer )
a->buffer = m_alloc( OP_MIN_PARTIAL_CHUNK );
memcpy( a->buffer + a->buflen, buf, size );
a->buflen += size;
}
else { /* okay, we can write out something */
/* do this in a loop to use the most efficient block lengths */
p = buf;
do {
/* find the best matching block length - this is limited
* by the size of the internal buffering */
for( blen=OP_MIN_PARTIAL_CHUNK*2,
c=OP_MIN_PARTIAL_CHUNK_2POW+1; blen <= nbytes;
blen *=2, c++ )
;
blen /= 2; c--;
/* write the partial length header */
assert( c <= 0x1f ); /*;-)*/
c |= 0xe0;
iobuf_put( chain, c );
if( (n=a->buflen) ) { /* write stuff from the buffer */
assert( n == OP_MIN_PARTIAL_CHUNK);
if( iobuf_write(chain, a->buffer, n ) )
rc = G10ERR_WRITE_FILE;
a->buflen = 0;
nbytes -= n;
}
if( (n = nbytes) > blen )
n = blen;
if( n && iobuf_write(chain, p, n ) )
rc = G10ERR_WRITE_FILE;
p += n;
nbytes -= n;
} while( !rc && nbytes >= OP_MIN_PARTIAL_CHUNK );
/* store the rest in the buffer */
if( !rc && nbytes ) {
assert( !a->buflen );
assert( nbytes < OP_MIN_PARTIAL_CHUNK );
if( !a->buffer )
a->buffer = m_alloc( OP_MIN_PARTIAL_CHUNK );
memcpy( a->buffer, p, nbytes );
a->buflen = nbytes;
}
}
}
else { /* the gnupg scheme (which is not openpgp compliant) */
size_t avail, n;
for(p=buf; !rc && size; ) {
n = size;
avail = a->size - a->count;
if( !avail ) {
if( n > a->size ) {
iobuf_put( chain, (a->size >> 8) & 0xff );
iobuf_put( chain, a->size & 0xff );
avail = a->size;
a->count = 0;
}
else {
iobuf_put( chain, (n >> 8) & 0xff );
iobuf_put( chain, n & 0xff );
avail = n;
a->count = a->size - n;
}
}
if( n > avail )
n = avail;
if( iobuf_write(chain, p, n ) )
rc = G10ERR_WRITE_FILE;
a->count += n;
p += n;
size -= n;
}
}
}
else if( control == IOBUFCTRL_INIT ) {
if( DBG_IOBUF )
log_debug("init block_filter %p\n", a );
if( a->partial )
a->count = 0;
else if( a->use == 1 )
a->count = a->size = 0;
else
a->count = a->size; /* force first length bytes */
a->eof = 0;
a->buffer = NULL;
a->buflen = 0;
}
else if( control == IOBUFCTRL_DESC ) {
*(char**)buf = "block_filter";
}
else if( control == IOBUFCTRL_FREE ) {
if( a->use == 2 ) { /* write the end markers */
if( a->partial ) {
u32 len;
/* write out the remaining bytes without a partial header
* the length of this header may be 0 - but if it is
* the first block we are not allowed to use a partial header
* and frankly we can't do so, because this length must be
* a power of 2. This is _really_ complicated because we
* have to check the possible length of a packet prior
* to it's creation: a chain of filters becomes complicated
* and we need a lot of code to handle compressed packets etc.
* :-(((((((
*/
/* construct header */
len = a->buflen;
if( len < 192 )
rc = iobuf_put(chain, len );
else if( len < 8384 ) {
if( !(rc=iobuf_put( chain, ((len-192) / 256) + 192)) )
rc = iobuf_put( chain, ((len-192) % 256));
}
else { /* use a 4 byte header */
if( !(rc=iobuf_put( chain, 0xff )) )
if( !(rc=iobuf_put( chain, (len >> 24)&0xff )) )
if( !(rc=iobuf_put( chain, (len >> 16)&0xff )) )
if( !(rc=iobuf_put( chain, (len >> 8)&0xff )))
rc=iobuf_put( chain, len & 0xff );
}
if( !rc && len )
rc = iobuf_write(chain, a->buffer, len );
if( rc ) {
log_error("block_filter: write error: %s\n",strerror(errno));
rc = G10ERR_WRITE_FILE;
}
m_free( a->buffer ); a->buffer = NULL; a->buflen = 0;
}
else {
iobuf_writebyte(chain, 0);
iobuf_writebyte(chain, 0);
}
}
else if( a->size ) {
log_error("block_filter: pending bytes!\n");
}
if( DBG_IOBUF )
log_debug("free block_filter %p\n", a );
m_free(a); /* we can free our context now */
}
return rc;
}
static void
print_chain( IOBUF a )
{
if( !DBG_IOBUF )
return;
for(; a; a = a->chain ) {
size_t dummy_len = 0;
const char *desc = "[none]";
if( a->filter )
a->filter( a->filter_ov, IOBUFCTRL_DESC, NULL,
(byte*)&desc, &dummy_len );
log_debug("iobuf chain: %d.%d `%s' filter_eof=%d start=%d len=%d\n",
a->no, a->subno, desc, a->filter_eof,
a->d.start, a->d.len );
}
}
/****************
* Allocate a new io buffer, with no function assigned.
* Use is the desired usage: 1 for input, 2 for output, 3 for temp buffer
* BUFSIZE is a suggested buffer size.
*/
IOBUF
iobuf_alloc(int use, size_t bufsize)
{
IOBUF a;
static int number=0;
a = m_alloc_clear(sizeof *a);
a->use = use;
a->d.buf = m_alloc( bufsize );
a->d.size = bufsize;
a->no = ++number;
a->subno = 0;
a->opaque = NULL;
return a;
}
int
iobuf_close( IOBUF a )
{
IOBUF a2;
size_t dummy_len;
int rc=0;
if( a && a->directfp ) {
fclose( a->directfp );
if( DBG_IOBUF )
log_debug("iobuf_close -> %p\n", a->directfp );
return 0;
}
for( ; a && !rc ; a = a2 ) {
a2 = a->chain;
if( a->use == 2 && (rc=iobuf_flush(a)) )
log_error("iobuf_flush failed on close: %s\n", g10_errstr(rc));
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: close `%s'\n", a->no, a->subno, a->desc );
if( a->filter && (rc = a->filter(a->filter_ov, IOBUFCTRL_FREE,
a->chain, NULL, &dummy_len)) )
log_error("IOBUFCTRL_FREE failed on close: %s\n", g10_errstr(rc) );
m_free(a->d.buf);
m_free(a);
}
return rc;
}
int
iobuf_cancel( IOBUF a )
{
const char *s;
if( a && a->use == 2 ) {
s = get_real_fname(a);
if( s && *s )
remove(s); /* remove the file. Fixme: this will fail for MSDOZE*/
} /* because the file is still open */
return iobuf_close(a);
}
/****************
* create a temporary iobuf, which can be used to collect stuff
* in an iobuf and later be written by iobuf_write_temp() to another
* iobuf.
*/
IOBUF
iobuf_temp()
{
IOBUF a;
a = iobuf_alloc(3, 8192 );
return a;
}
IOBUF
iobuf_temp_with_content( const char *buffer, size_t length )
{
IOBUF a;
a = iobuf_alloc(3, length );
memcpy( a->d.buf, buffer, length );
a->d.len = length;
return a;
}
/****************
* Create a head iobuf for reading from a file
* returns: NULL if an error occures and sets errno
*/
IOBUF
iobuf_open( const char *fname )
{
IOBUF a;
FILE *fp;
file_filter_ctx_t *fcx;
size_t len;
int print_only = 0;
if( !fname || (*fname=='-' && !fname[1]) ) {
fp = stdin; /* fixme: set binary mode for msdoze */
fname = "[stdin]";
print_only = 1;
}
else if( !(fp = fopen(fname, "rb")) )
return NULL;
a = iobuf_alloc(1, 8192 );
fcx = m_alloc( sizeof *fcx + strlen(fname) );
fcx->fp = fp;
fcx->print_only_name = print_only;
strcpy(fcx->fname, fname );
a->filter = file_filter;
a->filter_ov = fcx;
file_filter( fcx, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &len );
file_filter( fcx, IOBUFCTRL_INIT, NULL, NULL, &len );
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: open `%s' fd=%d\n",
a->no, a->subno, fname, fileno(fcx->fp) );
return a;
}
/****************
* Create a head iobuf for reading from a file
* returns: NULL if an error occures and sets errno
*/
IOBUF
iobuf_fdopen( int fd, const char *mode )
{
IOBUF a;
FILE *fp;
file_filter_ctx_t *fcx;
size_t len;
if( !(fp = fdopen(fd, mode)) )
return NULL;
a = iobuf_alloc( strchr( mode, 'w')? 2:1, 8192 );
fcx = m_alloc( sizeof *fcx + 20 );
fcx->fp = fp;
fcx->print_only_name = 1;
sprintf(fcx->fname, "[fd %d]", fd );
a->filter = file_filter;
a->filter_ov = fcx;
file_filter( fcx, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &len );
file_filter( fcx, IOBUFCTRL_INIT, NULL, NULL, &len );
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: fdopen `%s'\n", a->no, a->subno, fcx->fname );
return a;
}
/****************
* create an iobuf for writing to a file; the file will be created.
*/
IOBUF
iobuf_create( const char *fname )
{
IOBUF a;
FILE *fp;
file_filter_ctx_t *fcx;
size_t len;
int print_only = 0;
if( !fname || (*fname=='-' && !fname[1]) ) {
fp = stdout;
fname = "[stdout]";
print_only = 1;
}
else if( !(fp = fopen(fname, "wb")) )
return NULL;
a = iobuf_alloc(2, 8192 );
fcx = m_alloc( sizeof *fcx + strlen(fname) );
fcx->fp = fp;
fcx->print_only_name = print_only;
strcpy(fcx->fname, fname );
a->filter = file_filter;
a->filter_ov = fcx;
file_filter( fcx, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &len );
file_filter( fcx, IOBUFCTRL_INIT, NULL, NULL, &len );
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: create `%s'\n", a->no, a->subno, a->desc );
return a;
}
/****************
* append to an iobuf; if the file does not exist, create it.
* cannot be used for stdout.
*/
IOBUF
iobuf_append( const char *fname )
{
IOBUF a;
FILE *fp;
file_filter_ctx_t *fcx;
size_t len;
if( !fname )
return NULL;
else if( !(fp = fopen(fname, "ab")) )
return NULL;
a = iobuf_alloc(2, 8192 );
fcx = m_alloc( sizeof *fcx + strlen(fname) );
fcx->fp = fp;
strcpy(fcx->fname, fname );
a->filter = file_filter;
a->filter_ov = fcx;
file_filter( fcx, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &len );
file_filter( fcx, IOBUFCTRL_INIT, NULL, NULL, &len );
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: append `%s'\n", a->no, a->subno, a->desc );
return a;
}
IOBUF
iobuf_openrw( const char *fname )
{
IOBUF a;
FILE *fp;
file_filter_ctx_t *fcx;
size_t len;
if( !fname )
return NULL;
else if( !(fp = fopen(fname, "r+b")) )
return NULL;
a = iobuf_alloc(2, 8192 );
fcx = m_alloc( sizeof *fcx + strlen(fname) );
fcx->fp = fp;
strcpy(fcx->fname, fname );
a->filter = file_filter;
a->filter_ov = fcx;
file_filter( fcx, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &len );
file_filter( fcx, IOBUFCTRL_INIT, NULL, NULL, &len );
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: openrw `%s'\n", a->no, a->subno, a->desc );
return a;
}
/****************
* You can overwrite the normal iobuf behaviour by using this function.
* If used the iobuf is a simple wrapper around stdio.
* NULL if an error occures and sets errno
*/
IOBUF
iobuf_fopen( const char *fname, const char *mode )
{
IOBUF a;
FILE *fp;
int print_only = 0;
if( !fname || (*fname=='-' && !fname[1]) ) {
fp = stdin; /* fixme: set binary mode for msdoze */
fname = "[stdin]";
print_only = 1;
}
else if( !(fp = fopen(fname, mode) ) )
return NULL;
a = iobuf_alloc(1, 8192 );
a->directfp = fp;
if( DBG_IOBUF )
log_debug("iobuf_fopen -> %p\n", a->directfp );
return a;
}
/****************
* Register an i/o filter.
*/
int
iobuf_push_filter( IOBUF a,
int (*f)(void *opaque, int control,
IOBUF chain, byte *buf, size_t *len), void *ov )
{
return iobuf_push_filter2( a, f, ov, 0 );
}
int
iobuf_push_filter2( IOBUF a,
int (*f)(void *opaque, int control,
IOBUF chain, byte *buf, size_t *len),
void *ov, int rel_ov )
{
IOBUF b;
size_t dummy_len=0;
int rc=0;
if( a->directfp )
BUG();
if( a->use == 2 && (rc=iobuf_flush(a)) )
return rc;
/* make a copy of the current stream, so that
* A is the new stream and B the original one.
* The contents of the buffers are transferred to the
* new stream.
*/
b = m_alloc(sizeof *b);
memcpy(b, a, sizeof *b );
/* remove the filter stuff from the new stream */
a->filter = NULL;
a->filter_ov = NULL;
a->filter_ov_owner = 0;
a->filter_eof = 0;
if( a->use == 3 )
a->use = 2; /* make a write stream from a temp stream */
if( a->use == 2 ) { /* allocate a fresh buffer for the original stream */
b->d.buf = m_alloc( a->d.size );
b->d.len = 0;
b->d.start = 0;
}
else { /* allocate a fresh buffer for the new stream */
a->d.buf = m_alloc( a->d.size );
a->d.len = 0;
a->d.start = 0;
}
/* disable nlimit for the new stream */
a->ntotal = b->ntotal + b->nbytes;
a->nlimit = a->nbytes = 0;
a->nofast &= ~1;
/* make a link from the new stream to the original stream */
a->chain = b;
a->opaque = b->opaque;
/* setup the function on the new stream */
a->filter = f;
a->filter_ov = ov;
a->filter_ov_owner = rel_ov;
a->subno = b->subno + 1;
f( ov, IOBUFCTRL_DESC, NULL, (byte*)&a->desc, &dummy_len );
if( DBG_IOBUF ) {
log_debug("iobuf-%d.%d: push `%s'\n", a->no, a->subno, a->desc );
print_chain( a );
}
/* now we can initialize the new function if we have one */
if( a->filter && (rc = a->filter(a->filter_ov, IOBUFCTRL_INIT, a->chain,
NULL, &dummy_len)) )
log_error("IOBUFCTRL_INIT failed: %s\n", g10_errstr(rc) );
return rc;
}
/****************
* Remove an i/o filter.
*/
static int
pop_filter( IOBUF a, int (*f)(void *opaque, int control,
IOBUF chain, byte *buf, size_t *len), void *ov )
{
IOBUF b;
size_t dummy_len=0;
int rc=0;
if( a->directfp )
BUG();
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: pop `%s'\n", a->no, a->subno, a->desc );
if( !a->filter ) { /* this is simple */
b = a->chain;
assert(b);
m_free(a->d.buf);
memcpy(a,b, sizeof *a);
m_free(b);
return 0;
}
for(b=a ; b; b = b->chain )
if( b->filter == f && (!ov || b->filter_ov == ov) )
break;
if( !b )
log_bug("pop_filter(): filter function not found\n");
/* flush this stream if it is an output stream */
if( a->use == 2 && (rc=iobuf_flush(b)) ) {
log_error("iobuf_flush failed in pop_filter: %s\n", g10_errstr(rc));
return rc;
}
/* and tell the filter to free it self */
if( b->filter && (rc = b->filter(b->filter_ov, IOBUFCTRL_FREE, b->chain,
NULL, &dummy_len)) ) {
log_error("IOBUFCTRL_FREE failed: %s\n", g10_errstr(rc) );
return rc;
}
if( b->filter_ov && b->filter_ov_owner ) {
m_free( b->filter_ov );
b->filter_ov = NULL;
}
/* and see how to remove it */
if( a == b && !b->chain )
log_bug("can't remove the last filter from the chain\n");
else if( a == b ) { /* remove the first iobuf from the chain */
/* everything from b is copied to a. This is save because
* a flush has been done on the to be removed entry
*/
b = a->chain;
m_free(a->d.buf);
memcpy(a,b, sizeof *a);
m_free(b);
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: popped filter\n", a->no, a->subno );
}
else if( !b->chain ) { /* remove the last iobuf from the chain */
log_bug("Ohh jeee, trying to remove a head filter\n");
}
else { /* remove an intermediate iobuf from the chain */
log_bug("Ohh jeee, trying to remove an intermediate filter\n");
}
return rc;
}
/****************
* read underflow: read more bytes into the buffer and return
* the first byte or -1 on EOF.
*/
static int
underflow(IOBUF a)
{
size_t len;
int rc;
assert( a->d.start == a->d.len );
if( a->use == 3 )
return -1; /* EOF because a temp buffer can't do an underflow */
if( a->filter_eof ) {
if( a->chain && a->filter_eof == 1 ) {
IOBUF b = a->chain;
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: pop `%s' in underflow\n",
a->no, a->subno, a->desc );
m_free(a->d.buf);
memcpy(a, b, sizeof *a);
m_free(b);
print_chain(a);
}
else
a->filter_eof = 0;
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: underflow: eof (due to filter eof)\n",
a->no, a->subno );
return -1; /* return one(!) EOF */
}
if( a->error ) {
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: error\n", a->no, a->subno );
return -1;
}
if( a->directfp ) {
FILE *fp = a->directfp;
len = fread( a->d.buf, 1, a->d.size, fp);
if( len < a->d.size ) {
if( ferror(fp) )
a->error = 1;
}
a->d.len = len;
a->d.start = 0;
return len? a->d.buf[a->d.start++] : -1;
}
if( a->filter ) {
len = a->d.size;
rc = a->filter( a->filter_ov, IOBUFCTRL_UNDERFLOW, a->chain,
a->d.buf, &len );
if( DBG_IOBUF ) {
log_debug("iobuf-%d.%d: underflow: req=%lu got=%lu rc=%d\n",
a->no, a->subno, (ulong)a->d.size, (ulong)len, rc );
#if 0
if( a->no == 7 ) {
print_string(stderr, a->d.buf, len, 0 );
putc('\n', stderr );
}
#endif
}
if( a->use == 1 && rc == -1 ) { /* EOF: we can remove the filter */
size_t dummy_len;
/* and tell the filter to free itself */
if( (rc = a->filter(a->filter_ov, IOBUFCTRL_FREE, a->chain,
NULL, &dummy_len)) )
log_error("IOBUFCTRL_FREE failed: %s\n", g10_errstr(rc) );
if( a->filter_ov && a->filter_ov_owner ) {
m_free( a->filter_ov );
a->filter_ov = NULL;
}
a->filter = NULL;
a->desc = NULL;
a->filter_ov = NULL;
a->filter_eof = 1;
if( !len && a->chain ) {
IOBUF b = a->chain;
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: pop `%s' in underflow (!len)\n",
a->no, a->subno, a->desc );
print_chain(a);
m_free(a->d.buf);
memcpy(a,b, sizeof *a);
m_free(b);
print_chain(a);
}
}
else if( rc )
a->error = 1;
if( !len ) {
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: underflow: eof\n", a->no, a->subno );
return -1;
}
a->d.len = len;
a->d.start = 0;
return a->d.buf[a->d.start++];
}
else {
if( DBG_IOBUF )
log_debug("iobuf-%d.%d: underflow: eof (no filter)\n",
a->no, a->subno );
return -1; /* no filter; return EOF */
}
}
int
iobuf_flush(IOBUF a)
{
size_t len;
int rc;
if( a->directfp )
return 0;
/*log_debug("iobuf-%d.%d: flush\n", a->no, a->subno );*/
if( a->use == 3 ) { /* increase the temp buffer */
char *newbuf;
size_t newsize = a->d.size + 8192;
log_debug("increasing temp iobuf from %lu to %lu\n",
(ulong)a->d.size, (ulong)newsize );
newbuf = m_alloc( newsize );
memcpy( newbuf, a->d.buf, a->d.len );
m_free(a->d.buf);
a->d.buf = newbuf;
a->d.size = newsize;
return 0;
}
else if( a->use != 2 )
log_bug("flush on non-output iobuf\n");
else if( !a->filter )
log_bug("iobuf_flush: no filter\n");
len = a->d.len;
rc = a->filter( a->filter_ov, IOBUFCTRL_FLUSH, a->chain, a->d.buf, &len );
if( !rc && len != a->d.len ) {
log_info("iobuf_flush did not write all!\n");
rc = G10ERR_WRITE_FILE;
}
else if( rc )
a->error = 1;
a->d.len = 0;
return rc;
}
/****************
* Read a byte from the iobuf; returns -1 on EOF
*/
int
iobuf_readbyte(IOBUF a)
{
int c;
/* nlimit does not work together with unget */
/* nbytes is also not valid! */
if( a->unget.buf ) {
if( a->unget.start < a->unget.len )
return a->unget.buf[a->unget.start++];
m_free(a->unget.buf);
a->unget.buf = NULL;
a->nofast &= ~2;
}
if( a->nlimit && a->nbytes >= a->nlimit )
return -1; /* forced EOF */
if( a->d.start < a->d.len ) {
c = a->d.buf[a->d.start++];
}
else if( (c=underflow(a)) == -1 )
return -1; /* EOF */
a->nbytes++;
return c;
}
int
iobuf_read(IOBUF a, byte *buf, unsigned buflen )
{
int c, n;
if( a->unget.buf || a->nlimit ) {
/* handle special cases */
for(n=0 ; n < buflen; n++, buf++ ) {
if( (c = iobuf_readbyte(a)) == -1 ) {
if( !n )
return -1; /* eof */
break;
}
else
*buf = c;
}
return n;
}
n = 0;
do {
for( ; n < buflen && a->d.start < a->d.len; n++ )
*buf++ = a->d.buf[a->d.start++];
if( n < buflen ) {
if( (c=underflow(a)) == -1 ) {
a->nbytes += n;
return n? n : -1/*EOF*/;
}
*buf++ = c; n++;
}
} while( n < buflen );
a->nbytes += n;
return n;
}
/****************
* Have a look at the iobuf.
* NOTE: This only works in special cases.
*/
int
iobuf_peek(IOBUF a, byte *buf, unsigned buflen )
{
int n=0;
if( a->filter_eof )
return -1;
if( !(a->d.start < a->d.len) ) {
if( underflow(a) == -1 )
return -1;
/* and unget this character */
assert(a->d.start == 1);
a->d.start = 0;
}
for(n=0 ; n < buflen && (a->d.start+n) < a->d.len ; n++, buf++ )
*buf = a->d.buf[n];
return n;
}
int
iobuf_writebyte(IOBUF a, unsigned c)
{
if( a->directfp )
BUG();
if( a->d.len == a->d.size )
if( iobuf_flush(a) )
return -1;
assert( a->d.len < a->d.size );
a->d.buf[a->d.len++] = c;
return 0;
}
int
iobuf_write(IOBUF a, byte *buf, unsigned buflen )
{
if( a->directfp )
BUG();
do {
for( ; buflen && a->d.len < a->d.size; buflen--, buf++ )
a->d.buf[a->d.len++] = *buf;
if( buflen ) {
if( iobuf_flush(a) )
return -1;
}
} while( buflen );
return 0;
}
int
iobuf_writestr(IOBUF a, const char *buf )
{
for( ; *buf; buf++ )
if( iobuf_writebyte(a, *buf) )
return -1;
return 0;
}
/****************
* copy the contents of TEMP to A.
*/
int
iobuf_write_temp( IOBUF a, IOBUF temp )
{
while( temp->chain )
pop_filter( temp, temp->filter, NULL );
return iobuf_write(a, temp->d.buf, temp->d.len );
}
/****************
* copy the contents of the temp io stream to BUFFER.
*/
size_t
iobuf_temp_to_buffer( IOBUF a, byte *buffer, size_t buflen )
{
size_t n = a->d.len;
if( n > buflen )
n = buflen;
memcpy( buffer, a->d.buf, n );
return n;
}
/****************
* Call this function to terminate processing of the temp stream
* without closing it. This removes all filters from the stream
* makes sure that iobuf_get_temp_{buffer,length}() returns correct
* values.
*/
void
iobuf_flush_temp( IOBUF temp )
{
while( temp->chain )
pop_filter( temp, temp->filter, NULL );
}
/****************
* Set a limit on how many bytes may be read from the input stream A.
* Setting the limit to 0 disables this feature.
*/
void
iobuf_set_limit( IOBUF a, unsigned long nlimit )
{
if( nlimit )
a->nofast |= 1;
else
a->nofast &= ~1;
a->nlimit = nlimit;
a->ntotal += a->nbytes;
a->nbytes = 0;
}
/****************
* Return the length of an open file
*/
u32
iobuf_get_filelength( IOBUF a )
{
struct stat st;
if( a->directfp ) {
FILE *fp = a->directfp;
if( !fstat(fileno(fp), &st) )
return st.st_size;
log_error("fstat() failed: %s\n", strerror(errno) );
return 0;
}
for( ; a; a = a->chain )
if( !a->chain && a->filter == file_filter ) {
file_filter_ctx_t *b = a->filter_ov;
FILE *fp = b->fp;
if( !fstat(fileno(fp), &st) )
return st.st_size;
log_error("fstat() failed: %s\n", strerror(errno) );
break;
}
return 0;
}
/****************
* Tell the file position, where the next read will take place
*/
ulong
iobuf_tell( IOBUF a )
{
return a->ntotal + a->nbytes;
}
/****************
* This is a very limited implementation. It simply discards all internal
* buffering and removes all filters but the first one.
*/
int
iobuf_seek( IOBUF a, ulong newpos )
{
file_filter_ctx_t *b = NULL;
if( a->directfp ) {
FILE *fp = a->directfp;
if( fseek( fp, newpos, SEEK_SET ) ) {
log_error("can't seek to %lu: %s\n", newpos, strerror(errno) );
return -1;
}
clearerr(fp);
}
else {
for( ; a; a = a->chain ) {
if( !a->chain && a->filter == file_filter ) {
b = a->filter_ov;
break;
}
}
if( !a )
return -1;
if( fseek( b->fp, newpos, SEEK_SET ) ) {
log_error("can't seek to %lu: %s\n", newpos, strerror(errno) );
return -1;
}
}
a->d.len = 0; /* discard buffer */
a->d.start = 0;
a->nbytes = 0;
a->nlimit = 0;
a->nofast &= ~1;
a->ntotal = newpos;
a->error = 0;
/* remove filters, but the last */
if( a->chain )
log_debug("pop_filter called in iobuf_seek - please report\n");
while( a->chain )
pop_filter( a, a->filter, NULL );
return 0;
}
/****************
* Retrieve the real filename
*/
static const char *
get_real_fname( IOBUF a )
{
for( ; a; a = a->chain )
if( !a->chain && a->filter == file_filter ) {
file_filter_ctx_t *b = a->filter_ov;
return b->print_only_name? NULL : b->fname;
}
return NULL;
}
/****************
* Retrieve the filename
*/
const char *
iobuf_get_fname( IOBUF a )
{
for( ; a; a = a->chain )
if( !a->chain && a->filter == file_filter ) {
file_filter_ctx_t *b = a->filter_ov;
return b->fname;
}
return NULL;
}
/****************
* Start the block write mode, see rfc1991.new for details.
* A value of 0 for N stops this mode (flushes and writes
* the end marker)
*/
void
iobuf_set_block_mode( IOBUF a, size_t n )
{
block_filter_ctx_t *ctx = m_alloc_clear( sizeof *ctx );
assert( a->use == 1 || a->use == 2 );
ctx->use = a->use;
if( !n ) {
if( a->use == 1 )
log_debug("pop_filter called in set_block_mode - please report\n");
pop_filter(a, block_filter, NULL );
}
else {
ctx->size = n; /* only needed for use 2 */
iobuf_push_filter(a, block_filter, ctx );
}
}
/****************
* enable partial block mode as described in the OpenPGP draft.
* LEN is the first length byte on read, but ignored on writes.
*/
void
iobuf_set_partial_block_mode( IOBUF a, size_t len )
{
block_filter_ctx_t *ctx = m_alloc_clear( sizeof *ctx );
assert( a->use == 1 || a->use == 2 );
ctx->use = a->use;
if( !len ) {
if( a->use == 1 )
log_debug("pop_filter called in set_partial_block_mode"
" - please report\n");
pop_filter(a, block_filter, NULL );
}
else {
ctx->partial = 1;
ctx->size = 0;
ctx->first_c = len;
iobuf_push_filter(a, block_filter, ctx );
}
}
/****************
* Checks whether the stream is in block mode
* Note: This does not work if other filters are pushed on the stream.
*/
int
iobuf_in_block_mode( IOBUF a )
{
if( a && a->filter == block_filter )
return 1; /* yes */
return 0; /* no */
}
/****************
* Same as fgets() but if the buffer is too short a larger one will
* be allocated up to some limit *max_length.
* A line is considered a byte stream ending in a LF.
* Returns the length of the line. EOF is indicated by a line of
* length zero. The last LF may be missing due to an EOF.
* is max_length is zero on return, the line has been truncated.
*
* Note: The buffer is allocated with enough space to append a CR,LF,EOL
*/
unsigned
iobuf_read_line( IOBUF a, byte **addr_of_buffer,
unsigned *length_of_buffer, unsigned *max_length )
{
int c;
char *buffer = *addr_of_buffer;
unsigned length = *length_of_buffer;
unsigned nbytes = 0;
unsigned maxlen = *max_length;
char *p;
if( !buffer ) { /* must allocate a new buffer */
length = 256;
buffer = m_alloc( length );
*addr_of_buffer = buffer;
*length_of_buffer = length;
}
length -= 3; /* reserve 3 bytes (cr,lf,eol) */
p = buffer;
while( (c=iobuf_get(a)) != -1 ) {
if( nbytes == length ) { /* increase the buffer */
if( length > maxlen ) { /* this is out limit */
/* skip the rest of the line */
while( c != '\n' && (c=iobuf_get(a)) != -1 )
;
*p++ = '\n'; /* always append a LF (we have reserved space) */
nbytes++;
*max_length = 0; /* indicate truncation */
break;
}
length += 3; /* correct for the reserved byte */
length += length < 1024? 256 : 1024;
buffer = m_realloc( buffer, length );
*addr_of_buffer = buffer;
*length_of_buffer = length;
length -= 3; /* and reserve again */
p = buffer + nbytes;
}
*p++ = c;
nbytes++;
if( c == '\n' )
break;
}
*p = 0; /* make sure the line is a string */
return nbytes;
}
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