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Diffstat (limited to 'lib/mbuffers.h')
| -rw-r--r-- | lib/mbuffers.h | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/lib/mbuffers.h b/lib/mbuffers.h new file mode 100644 index 0000000..a41850c --- /dev/null +++ b/lib/mbuffers.h @@ -0,0 +1,201 @@ +/* + * Copyright (C) 2009-2012 Free Software Foundation, Inc. + * + * Author: Jonathan Bastien-Filiatrault + * + * This file is part of GNUTLS. + * + * The GNUTLS library 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. + * + * This library 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 <https://www.gnu.org/licenses/> + * + */ + +#ifndef GNUTLS_LIB_MBUFFERS_H +#define GNUTLS_LIB_MBUFFERS_H + +#include "gnutls_int.h" +#include "errors.h" +#include <assert.h> + +void _mbuffer_head_init(mbuffer_head_st * buf); +void _mbuffer_head_clear(mbuffer_head_st * buf); +void _mbuffer_enqueue(mbuffer_head_st * buf, mbuffer_st * bufel); +mbuffer_st *_mbuffer_dequeue(mbuffer_head_st * buf, mbuffer_st * bufel); +int _mbuffer_head_remove_bytes(mbuffer_head_st * buf, size_t bytes); +mbuffer_st *_mbuffer_alloc(size_t maximum_size); +int _mbuffer_linearize(mbuffer_head_st * buf); + +mbuffer_st *_mbuffer_head_get_first(mbuffer_head_st * buf, + gnutls_datum_t * msg); +mbuffer_st *_mbuffer_head_get_next(mbuffer_st * cur, gnutls_datum_t * msg); + +void _mbuffer_head_push_first(mbuffer_head_st * buf, mbuffer_st * bufel); + +mbuffer_st *_mbuffer_head_pop_first(mbuffer_head_st * buf); + +/* This is dangerous since it will replace bufel with a new + * one. + */ +int _mbuffer_append_data(mbuffer_st * bufel, void *newdata, + size_t newdata_size); + + +/* For "user" use. One can have buffer data and header. + */ + +inline static void *_mbuffer_get_uhead_ptr(mbuffer_st * bufel) +{ + return bufel->msg.data + bufel->mark; +} + +inline static void *_mbuffer_get_udata_ptr(mbuffer_st * bufel) +{ + return bufel->msg.data + bufel->uhead_mark + bufel->mark; +} + +inline static void _mbuffer_set_udata_size(mbuffer_st * bufel, size_t size) +{ + bufel->msg.size = size + bufel->uhead_mark + bufel->mark; +} + +inline static void +_mbuffer_set_udata(mbuffer_st * bufel, void *data, size_t data_size) +{ + memcpy(_mbuffer_get_udata_ptr(bufel), data, + data_size); + _mbuffer_set_udata_size(bufel, data_size); +} + +inline static size_t _mbuffer_get_udata_size(mbuffer_st * bufel) +{ + return bufel->msg.size - bufel->uhead_mark - bufel->mark; +} + +/* discards size bytes from the begging of the buffer */ +inline static void +_mbuffer_consume(mbuffer_head_st * buf, mbuffer_st * bufel, size_t size) +{ + bufel->uhead_mark = 0; + if (bufel->mark + size < bufel->msg.size) + bufel->mark += size; + else + bufel->mark = bufel->msg.size; + + buf->byte_length -= size; +} + +inline static size_t _mbuffer_get_uhead_size(mbuffer_st * bufel) +{ + return bufel->uhead_mark; +} + +inline static void _mbuffer_set_uhead_size(mbuffer_st * bufel, size_t size) +{ + bufel->uhead_mark = size; +} + +inline static void _mbuffer_init(mbuffer_st *bufel, size_t max) +{ + memset(bufel, 0, sizeof(*bufel)); + bufel->maximum_size = max; + + /* payload points after the mbuffer_st structure */ + bufel->msg.data = (uint8_t *) bufel + sizeof(mbuffer_st); +} + +/* Helper functions to utilize a gnutls_buffer_st in order + * to generate a gnutls_mbuffer_st, without multiple allocations. + */ +inline static int _gnutls_buffer_init_mbuffer(gnutls_buffer_st * buf, size_t header_size) +{ + int ret; + mbuffer_st *bufel; + + _gnutls_buffer_init(buf); + + ret = _gnutls_buffer_resize(buf, sizeof(mbuffer_st)+header_size); + if (ret < 0) + return gnutls_assert_val(ret); + + /* we store the uhead size on the uninitialized bufel, only to read + * it back on _gnutls_buffer_to_mbuffer(). */ + bufel = (void*)buf->data; + _mbuffer_set_uhead_size(bufel, header_size); + + buf->length = sizeof(mbuffer_st)+header_size; + + return 0; +} + +#define _gnutls_buffer_init_handshake_mbuffer(b) _gnutls_buffer_init_mbuffer(b, HANDSHAKE_HEADER_SIZE(session)) + + +/* Cannot fail */ +inline static mbuffer_st *_gnutls_buffer_to_mbuffer(gnutls_buffer_st * buf) +{ + mbuffer_st *bufel; + unsigned header_size; + + bufel = (void*)buf->data; + + header_size = _mbuffer_get_uhead_size(bufel); + assert(buf->length >= sizeof(mbuffer_st)+header_size); + + _mbuffer_init(bufel, buf->length - sizeof(mbuffer_st)); + + _mbuffer_set_udata_size(bufel, buf->length - sizeof(mbuffer_st)); + _mbuffer_set_uhead_size(bufel, header_size); + + _gnutls_buffer_init(buf); /* avoid double frees */ + + return bufel; +} + +inline static mbuffer_st *_gnutls_handshake_alloc(gnutls_session_t session, + size_t maximum) +{ + mbuffer_st *bufel = + _mbuffer_alloc(HANDSHAKE_HEADER_SIZE(session) + maximum); + + if (!bufel) + return NULL; + + _mbuffer_set_uhead_size(bufel, HANDSHAKE_HEADER_SIZE(session)); + _mbuffer_set_udata_size(bufel, maximum); + + return bufel; +} + +/* Free a segment, if the pointer is not NULL + * + * We take a ** to detect and fix double free bugs (the dangling + * pointer case). It also makes sure the pointer has a known value + * after freeing. + */ +inline static void _mbuffer_xfree(mbuffer_st ** bufel) +{ + if (*bufel) + gnutls_free(*bufel); + + *bufel = NULL; +} + +#ifdef ENABLE_ALIGN16 +mbuffer_st *_mbuffer_alloc_align16(size_t maximum_size, unsigned align_pos); +int _mbuffer_linearize_align16(mbuffer_head_st * buf, unsigned align_pos); +#else +# define _mbuffer_alloc_align16(x,y) _mbuffer_alloc(x) +# define _mbuffer_linearize_align16(x,y) _mbuffer_linearize(x) +#endif + +#endif /* GNUTLS_LIB_MBUFFERS_H */ |