openssh-portable/buffer.c

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C
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/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Functions for manipulating fifo buffers (that can grow if needed).
*
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/09/05 02:59:57 [session.c] print hostname (not hushlogin) - markus@cvs.openbsd.org 2000/09/05 13:18:48 [authfile.c ssh-add.c] enable ssh-add -d for DSA keys - markus@cvs.openbsd.org 2000/09/05 13:20:49 [sftp-server.c] cleanup - markus@cvs.openbsd.org 2000/09/06 03:46:41 [authfile.h] prototype - deraadt@cvs.openbsd.org 2000/09/07 14:27:56 [ALL] cleanup copyright notices on all files. I have attempted to be accurate with the details. everything is now under Tatu's licence (which I copied from his readme), and/or the core-sdi bsd-ish thing for deattack, or various openbsd developers under a 2-term bsd licence. We're not changing any rules, just being accurate. - markus@cvs.openbsd.org 2000/09/07 14:40:30 [channels.c channels.h clientloop.c serverloop.c ssh.c] cleanup window and packet sizes for ssh2 flow control; ok niels - markus@cvs.openbsd.org 2000/09/07 14:53:00 [scp.c] typo - markus@cvs.openbsd.org 2000/09/07 15:13:37 [auth-options.c auth-options.h auth-rh-rsa.c auth-rsa.c auth.c] [authfile.h canohost.c channels.h compat.c hostfile.h log.c match.h] [pty.c readconf.c] some more Copyright fixes - markus@cvs.openbsd.org 2000/09/08 03:02:51 [README.openssh2] bye bye - deraadt@cvs.openbsd.org 2000/09/11 18:38:33 [LICENCE cipher.c] a few more comments about it being ARC4 not RC4 - markus@cvs.openbsd.org 2000/09/12 14:53:11 [log-client.c log-server.c log.c ssh.1 ssh.c ssh.h sshd.8 sshd.c] multiple debug levels - markus@cvs.openbsd.org 2000/09/14 14:25:15 [clientloop.c] typo - deraadt@cvs.openbsd.org 2000/09/15 01:13:51 [ssh-agent.c] check return value for setenv(3) for failure, and deal appropriately
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* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
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#include "includes.h"
- (djm) Merge OpenBSD changes: - markus@cvs.openbsd.org 2000/09/05 02:59:57 [session.c] print hostname (not hushlogin) - markus@cvs.openbsd.org 2000/09/05 13:18:48 [authfile.c ssh-add.c] enable ssh-add -d for DSA keys - markus@cvs.openbsd.org 2000/09/05 13:20:49 [sftp-server.c] cleanup - markus@cvs.openbsd.org 2000/09/06 03:46:41 [authfile.h] prototype - deraadt@cvs.openbsd.org 2000/09/07 14:27:56 [ALL] cleanup copyright notices on all files. I have attempted to be accurate with the details. everything is now under Tatu's licence (which I copied from his readme), and/or the core-sdi bsd-ish thing for deattack, or various openbsd developers under a 2-term bsd licence. We're not changing any rules, just being accurate. - markus@cvs.openbsd.org 2000/09/07 14:40:30 [channels.c channels.h clientloop.c serverloop.c ssh.c] cleanup window and packet sizes for ssh2 flow control; ok niels - markus@cvs.openbsd.org 2000/09/07 14:53:00 [scp.c] typo - markus@cvs.openbsd.org 2000/09/07 15:13:37 [auth-options.c auth-options.h auth-rh-rsa.c auth-rsa.c auth.c] [authfile.h canohost.c channels.h compat.c hostfile.h log.c match.h] [pty.c readconf.c] some more Copyright fixes - markus@cvs.openbsd.org 2000/09/08 03:02:51 [README.openssh2] bye bye - deraadt@cvs.openbsd.org 2000/09/11 18:38:33 [LICENCE cipher.c] a few more comments about it being ARC4 not RC4 - markus@cvs.openbsd.org 2000/09/12 14:53:11 [log-client.c log-server.c log.c ssh.1 ssh.c ssh.h sshd.8 sshd.c] multiple debug levels - markus@cvs.openbsd.org 2000/09/14 14:25:15 [clientloop.c] typo - deraadt@cvs.openbsd.org 2000/09/15 01:13:51 [ssh-agent.c] check return value for setenv(3) for failure, and deal appropriately
2000-09-16 04:29:08 +02:00
RCSID("$OpenBSD: buffer.c,v 1.8 2000/09/07 20:27:50 deraadt Exp $");
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#include "xmalloc.h"
#include "buffer.h"
#include "ssh.h"
/* Initializes the buffer structure. */
void
buffer_init(Buffer *buffer)
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{
buffer->alloc = 4096;
buffer->buf = xmalloc(buffer->alloc);
buffer->offset = 0;
buffer->end = 0;
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}
/* Frees any memory used for the buffer. */
void
buffer_free(Buffer *buffer)
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{
memset(buffer->buf, 0, buffer->alloc);
xfree(buffer->buf);
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}
/*
* Clears any data from the buffer, making it empty. This does not actually
* zero the memory.
*/
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void
buffer_clear(Buffer *buffer)
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{
buffer->offset = 0;
buffer->end = 0;
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}
/* Appends data to the buffer, expanding it if necessary. */
void
buffer_append(Buffer *buffer, const char *data, unsigned int len)
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{
char *cp;
buffer_append_space(buffer, &cp, len);
memcpy(cp, data, len);
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}
/*
* Appends space to the buffer, expanding the buffer if necessary. This does
* not actually copy the data into the buffer, but instead returns a pointer
* to the allocated region.
*/
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void
buffer_append_space(Buffer *buffer, char **datap, unsigned int len)
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{
/* If the buffer is empty, start using it from the beginning. */
if (buffer->offset == buffer->end) {
buffer->offset = 0;
buffer->end = 0;
}
restart:
/* If there is enough space to store all data, store it now. */
if (buffer->end + len < buffer->alloc) {
*datap = buffer->buf + buffer->end;
buffer->end += len;
return;
}
/*
* If the buffer is quite empty, but all data is at the end, move the
* data to the beginning and retry.
*/
if (buffer->offset > buffer->alloc / 2) {
memmove(buffer->buf, buffer->buf + buffer->offset,
buffer->end - buffer->offset);
buffer->end -= buffer->offset;
buffer->offset = 0;
goto restart;
}
/* Increase the size of the buffer and retry. */
buffer->alloc += len + 32768;
buffer->buf = xrealloc(buffer->buf, buffer->alloc);
goto restart;
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}
/* Returns the number of bytes of data in the buffer. */
unsigned int
buffer_len(Buffer *buffer)
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{
return buffer->end - buffer->offset;
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}
/* Gets data from the beginning of the buffer. */
void
buffer_get(Buffer *buffer, char *buf, unsigned int len)
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{
if (len > buffer->end - buffer->offset)
fatal("buffer_get: trying to get more bytes than in buffer");
memcpy(buf, buffer->buf + buffer->offset, len);
buffer->offset += len;
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}
/* Consumes the given number of bytes from the beginning of the buffer. */
void
buffer_consume(Buffer *buffer, unsigned int bytes)
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{
if (bytes > buffer->end - buffer->offset)
fatal("buffer_consume: trying to get more bytes than in buffer");
buffer->offset += bytes;
}
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/* Consumes the given number of bytes from the end of the buffer. */
void
buffer_consume_end(Buffer *buffer, unsigned int bytes)
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{
if (bytes > buffer->end - buffer->offset)
fatal("buffer_consume_end: trying to get more bytes than in buffer");
buffer->end -= bytes;
}
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/* Returns a pointer to the first used byte in the buffer. */
char *
buffer_ptr(Buffer *buffer)
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{
return buffer->buf + buffer->offset;
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}
/* Dumps the contents of the buffer to stderr. */
void
buffer_dump(Buffer *buffer)
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{
int i;
unsigned char *ucp = (unsigned char *) buffer->buf;
for (i = buffer->offset; i < buffer->end; i++)
fprintf(stderr, " %02x", ucp[i]);
fprintf(stderr, "\n");
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}